NEWS
author haftmann
Tue Jun 23 16:27:12 2009 +0200 (2009-06-23)
changeset 31784 bd3486c57ba3
parent 31726 ffd2dc631d88
child 31790 05c92381363c
permissions -rw-r--r--
tuned interfaces of datatype module
     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 * Class semiring_div requires superclass no_zero_divisors and proof of
    22 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    23 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    24 generalized to class semiring_div, subsuming former theorems
    25 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    26 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    27 INCOMPATIBILITY.
    28 
    29 * Power operations on relations and functions are now one dedicate
    30 constant compow with infix syntax "^^".  Power operations on
    31 multiplicative monoids retains syntax "^" and is now defined generic
    32 in class power.  INCOMPATIBILITY.
    33 
    34 * ML antiquotation @{code_datatype} inserts definition of a datatype
    35 generated by the code generator; see Predicate.thy for an example.
    36 
    37 * New method "linarith" invokes existing linear arithmetic decision
    38 procedure only.
    39 
    40 * Implementation of quickcheck using generic code generator; default generators
    41 are provided for all suitable HOL types, records and datatypes.
    42 
    43 * Constants Set.Pow and Set.image now with authentic syntax; object-logic definitions
    44 Set.Pow_def and Set.image_def.  INCOMPATIBILITY.
    45 
    46 * Discontinued ancient tradition to suffix certain ML module names with "_package", e.g.:
    47 
    48     DatatypePackage ~> Datatype
    49     InductivePackage ~> Inductive
    50 
    51     etc.
    52 
    53 INCOMPATIBILITY.
    54 
    55 * NewNumberTheory: Jeremy Avigad's new version of part of NumberTheory.
    56 If possible, use NewNumberTheory, not NumberTheory.
    57 
    58 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
    59 
    60 
    61 *** ML ***
    62 
    63 * Eliminated old Attrib.add_attributes, Method.add_methods and related
    64 cominators for "args".  INCOMPATIBILITY, need to use simplified
    65 Attrib/Method.setup introduced in Isabelle2009.
    66 
    67 
    68 *** System ***
    69 
    70 * Discontinued support for Poly/ML 4.x versions.
    71 
    72 * Removed "compress" option from isabelle-process and isabelle usedir;
    73 this is always enabled.
    74 
    75 
    76 
    77 New in Isabelle2009 (April 2009)
    78 --------------------------------
    79 
    80 *** General ***
    81 
    82 * Simplified main Isabelle executables, with less surprises on
    83 case-insensitive file-systems (such as Mac OS).
    84 
    85   - The main Isabelle tool wrapper is now called "isabelle" instead of
    86     "isatool."
    87 
    88   - The former "isabelle" alias for "isabelle-process" has been
    89     removed (should rarely occur to regular users).
    90 
    91   - The former "isabelle-interface" and its alias "Isabelle" have been
    92     removed (interfaces are now regular Isabelle tools).
    93 
    94 Within scripts and make files, the Isabelle environment variables
    95 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
    96 respectively.  (The latter are still available as legacy feature.)
    97 
    98 The old isabelle-interface wrapper could react in confusing ways if
    99 the interface was uninstalled or changed otherwise.  Individual
   100 interface tool configuration is now more explicit, see also the
   101 Isabelle system manual.  In particular, Proof General is now available
   102 via "isabelle emacs".
   103 
   104 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   105 purge installed copies of Isabelle executables and re-run "isabelle
   106 install -p ...", or use symlinks.
   107 
   108 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   109 old ~/isabelle, which was slightly non-standard and apt to cause
   110 surprises on case-insensitive file-systems (such as Mac OS).
   111 
   112 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   113 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   114 care is required when using older releases of Isabelle.  Note that
   115 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   116 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   117 
   118 * Proofs of fully specified statements are run in parallel on
   119 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   120 a regular 4-core machine, if the initial heap space is made reasonably
   121 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   122 
   123 * The main reference manuals ("isar-ref", "implementation", and
   124 "system") have been updated and extended.  Formally checked references
   125 as hyperlinks are now available uniformly.
   126 
   127 
   128 *** Pure ***
   129 
   130 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   131 respects.  The most important changes are listed below.  See the
   132 Tutorial on Locales ("locales" manual) for details.
   133 
   134 - In locale expressions, instantiation replaces renaming.  Parameters
   135 must be declared in a for clause.  To aid compatibility with previous
   136 parameter inheritance, in locale declarations, parameters that are not
   137 'touched' (instantiation position "_" or omitted) are implicitly added
   138 with their syntax at the beginning of the for clause.
   139 
   140 - Syntax from abbreviations and definitions in locales is available in
   141 locale expressions and context elements.  The latter is particularly
   142 useful in locale declarations.
   143 
   144 - More flexible mechanisms to qualify names generated by locale
   145 expressions.  Qualifiers (prefixes) may be specified in locale
   146 expressions, and can be marked as mandatory (syntax: "name!:") or
   147 optional (syntax "name?:").  The default depends for plain "name:"
   148 depends on the situation where a locale expression is used: in
   149 commands 'locale' and 'sublocale' prefixes are optional, in
   150 'interpretation' and 'interpret' prefixes are mandatory.  The old
   151 implicit qualifiers derived from the parameter names of a locale are
   152 no longer generated.
   153 
   154 - Command "sublocale l < e" replaces "interpretation l < e".  The
   155 instantiation clause in "interpretation" and "interpret" (square
   156 brackets) is no longer available.  Use locale expressions.
   157 
   158 - When converting proof scripts, mandatory qualifiers in
   159 'interpretation' and 'interpret' should be retained by default, even
   160 if this is an INCOMPATIBILITY compared to former behavior.  In the
   161 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   162 in locale expressions range over a single locale instance only.
   163 
   164 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   165 In existing theorem specifications replace the includes element by the
   166 respective context elements of the included locale, omitting those
   167 that are already present in the theorem specification.  Multiple
   168 assume elements of a locale should be replaced by a single one
   169 involving the locale predicate.  In the proof body, declarations (most
   170 notably theorems) may be regained by interpreting the respective
   171 locales in the proof context as required (command "interpret").
   172 
   173 If using "includes" in replacement of a target solely because the
   174 parameter types in the theorem are not as general as in the target,
   175 consider declaring a new locale with additional type constraints on
   176 the parameters (context element "constrains").
   177 
   178 - Discontinued "locale (open)".  INCOMPATIBILITY.
   179 
   180 - Locale interpretation commands no longer attempt to simplify goal.
   181 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   182 methods intro_locales and unfold_locales to clarify.
   183 
   184 - Locale interpretation commands no longer accept interpretation
   185 attributes.  INCOMPATIBILITY.
   186 
   187 * Class declaration: so-called "base sort" must not be given in import
   188 list any longer, but is inferred from the specification.  Particularly
   189 in HOL, write
   190 
   191     class foo = ...
   192 
   193 instead of
   194 
   195     class foo = type + ...
   196 
   197 * Class target: global versions of theorems stemming do not carry a
   198 parameter prefix any longer.  INCOMPATIBILITY.
   199 
   200 * Class 'instance' command no longer accepts attached definitions.
   201 INCOMPATIBILITY, use proper 'instantiation' target instead.
   202 
   203 * Recovered hiding of consts, which was accidentally broken in
   204 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   205 makes c inaccessible; consider using ``hide (open) const c'' instead.
   206 
   207 * Slightly more coherent Pure syntax, with updated documentation in
   208 isar-ref manual.  Removed locales meta_term_syntax and
   209 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   210 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   211 directly in regular applications.
   212 
   213 * There is a new syntactic category "float_const" for signed decimal
   214 fractions (e.g. 123.45 or -123.45).
   215 
   216 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   217 interface with 'setup' command instead.
   218 
   219 * Command 'local_setup' is similar to 'setup', but operates on a local
   220 theory context.
   221 
   222 * The 'axiomatization' command now only works within a global theory
   223 context.  INCOMPATIBILITY.
   224 
   225 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   226 hypotheses.  Sorts required in the course of reasoning need to be
   227 covered by the constraints in the initial statement, completed by the
   228 type instance information of the background theory.  Non-trivial sort
   229 hypotheses, which rarely occur in practice, may be specified via
   230 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   231 
   232   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   233 
   234 The result contains an implicit sort hypotheses as before --
   235 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   236 normalization.
   237 
   238 * Generalized Isar history, with support for linear undo, direct state
   239 addressing etc.
   240 
   241 * Changed defaults for unify configuration options:
   242 
   243   unify_trace_bound = 50 (formerly 25)
   244   unify_search_bound = 60 (formerly 30)
   245 
   246 * Different bookkeeping for code equations (INCOMPATIBILITY):
   247 
   248   a) On theory merge, the last set of code equations for a particular
   249      constant is taken (in accordance with the policy applied by other
   250      parts of the code generator framework).
   251 
   252   b) Code equations stemming from explicit declarations (e.g. code
   253      attribute) gain priority over default code equations stemming
   254      from definition, primrec, fun etc.
   255 
   256 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   257 
   258 * Unified theorem tables for both code generators.  Thus [code
   259 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   260 
   261 * Command 'find_consts' searches for constants based on type and name
   262 patterns, e.g.
   263 
   264     find_consts "_ => bool"
   265 
   266 By default, matching is against subtypes, but it may be restricted to
   267 the whole type.  Searching by name is possible.  Multiple queries are
   268 conjunctive and queries may be negated by prefixing them with a
   269 hyphen:
   270 
   271     find_consts strict: "_ => bool" name: "Int" -"int => int"
   272 
   273 * New 'find_theorems' criterion "solves" matches theorems that
   274 directly solve the current goal (modulo higher-order unification).
   275 
   276 * Auto solve feature for main theorem statements: whenever a new goal
   277 is stated, "find_theorems solves" is called; any theorems that could
   278 solve the lemma directly are listed as part of the goal state.
   279 Cf. associated options in Proof General Isabelle settings menu,
   280 enabled by default, with reasonable timeout for pathological cases of
   281 higher-order unification.
   282 
   283 
   284 *** Document preparation ***
   285 
   286 * Antiquotation @{lemma} now imitates a regular terminal proof,
   287 demanding keyword 'by' and supporting the full method expression
   288 syntax just like the Isar command 'by'.
   289 
   290 
   291 *** HOL ***
   292 
   293 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   294 points Main and Complex_Main remain as before.
   295 
   296 * Logic image HOL-Plain provides a minimal HOL with the most important
   297 tools available (inductive, datatype, primrec, ...).  This facilitates
   298 experimentation and tool development.  Note that user applications
   299 (and library theories) should never refer to anything below theory
   300 Main, as before.
   301 
   302 * Logic image HOL-Main stops at theory Main, and thus facilitates
   303 experimentation due to shorter build times.
   304 
   305 * Logic image HOL-NSA contains theories of nonstandard analysis which
   306 were previously part of former HOL-Complex.  Entry point Hyperreal
   307 remains valid, but theories formerly using Complex_Main should now use
   308 new entry point Hypercomplex.
   309 
   310 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   311 Posix processes.  Avoids potentially expensive forking of the ML
   312 process.  New thread-based implementation also works on non-Unix
   313 platforms (Cygwin).  Provers are no longer hardwired, but defined
   314 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   315 commands are covered in the isar-ref manual.
   316 
   317 * Wrapper scripts for remote SystemOnTPTP service allows to use
   318 sledgehammer without local ATP installation (Vampire etc.). Other
   319 provers may be included via suitable ML wrappers, see also
   320 src/HOL/ATP_Linkup.thy.
   321 
   322 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   323 menu.
   324 
   325 * The metis method no longer fails because the theorem is too trivial
   326 (contains the empty clause).
   327 
   328 * The metis method now fails in the usual manner, rather than raising
   329 an exception, if it determines that it cannot prove the theorem.
   330 
   331 * Method "coherent" implements a prover for coherent logic (see also
   332 src/Tools/coherent.ML).
   333 
   334 * Constants "undefined" and "default" replace "arbitrary".  Usually
   335 "undefined" is the right choice to replace "arbitrary", though
   336 logically there is no difference.  INCOMPATIBILITY.
   337 
   338 * Command "value" now integrates different evaluation mechanisms.  The
   339 result of the first successful evaluation mechanism is printed.  In
   340 square brackets a particular named evaluation mechanisms may be
   341 specified (currently, [SML], [code] or [nbe]).  See further
   342 src/HOL/ex/Eval_Examples.thy.
   343 
   344 * Normalization by evaluation now allows non-leftlinear equations.
   345 Declare with attribute [code nbe].
   346 
   347 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   348 as the structured Isar versions "cases" and "induct", cf. the
   349 corresponding "cases" and "induct" attributes.  Mutual induction rules
   350 are now presented as a list of individual projections
   351 (e.g. foo_bar.inducts for types foo and bar); the old format with
   352 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   353 rare situations a different rule is selected --- notably nested tuple
   354 elimination instead of former prod.exhaust: use explicit (case_tac t
   355 rule: prod.exhaust) here.
   356 
   357 * Attributes "cases", "induct", "coinduct" support "del" option.
   358 
   359 * Removed fact "case_split_thm", which duplicates "case_split".
   360 
   361 * The option datatype has been moved to a new theory Option.  Renamed
   362 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   363 
   364 * New predicate "strict_mono" classifies strict functions on partial
   365 orders.  With strict functions on linear orders, reasoning about
   366 (in)equalities is facilitated by theorems "strict_mono_eq",
   367 "strict_mono_less_eq" and "strict_mono_less".
   368 
   369 * Some set operations are now proper qualified constants with
   370 authentic syntax.  INCOMPATIBILITY:
   371 
   372     op Int ~>   Set.Int
   373     op Un ~>    Set.Un
   374     INTER ~>    Set.INTER
   375     UNION ~>    Set.UNION
   376     Inter ~>    Set.Inter
   377     Union ~>    Set.Union
   378     {} ~>       Set.empty
   379     UNIV ~>     Set.UNIV
   380 
   381 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   382 theory Set.
   383 
   384 * Auxiliary class "itself" has disappeared -- classes without any
   385 parameter are treated as expected by the 'class' command.
   386 
   387 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   388 
   389 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   390 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   391 
   392 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   393 method "approximation".  It proves formulas on real values by using
   394 interval arithmetic.  In the formulas are also the transcendental
   395 functions sin, cos, tan, atan, ln, exp and the constant pi are
   396 allowed. For examples see
   397 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   398 
   399 * Theory "Reflection" now resides in HOL/Library.
   400 
   401 * Entry point to Word library now simply named "Word".
   402 INCOMPATIBILITY.
   403 
   404 * Made source layout more coherent with logical distribution
   405 structure:
   406 
   407     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   408     src/HOL/Library/Code_Message.thy ~> src/HOL/
   409     src/HOL/Library/GCD.thy ~> src/HOL/
   410     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   411     src/HOL/Library/Parity.thy ~> src/HOL/
   412     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   413     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   414     src/HOL/Real/Lubs.thy ~> src/HOL/
   415     src/HOL/Real/PReal.thy ~> src/HOL/
   416     src/HOL/Real/Rational.thy ~> src/HOL/
   417     src/HOL/Real/RComplete.thy ~> src/HOL/
   418     src/HOL/Real/RealDef.thy ~> src/HOL/
   419     src/HOL/Real/RealPow.thy ~> src/HOL/
   420     src/HOL/Real/Real.thy ~> src/HOL/
   421     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   422     src/HOL/Complex/Complex.thy ~> src/HOL/
   423     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   424     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   425     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   426     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   427     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   428     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   429     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   430     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   431     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   432     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   433     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   434     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   435     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   436     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   437     src/HOL/Real/Float ~> src/HOL/Library/
   438     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   439     src/HOL/Real/RealVector.thy ~> src/HOL/
   440 
   441     src/HOL/arith_data.ML ~> src/HOL/Tools
   442     src/HOL/hologic.ML ~> src/HOL/Tools
   443     src/HOL/simpdata.ML ~> src/HOL/Tools
   444     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   445     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   446     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   447     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   448     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   449     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   450     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   451 
   452     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   453     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   454     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   455     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   456     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   457     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   458 
   459 * If methods "eval" and "evaluation" encounter a structured proof
   460 state with !!/==>, only the conclusion is evaluated to True (if
   461 possible), avoiding strange error messages.
   462 
   463 * Method "sizechange" automates termination proofs using (a
   464 modification of) the size-change principle.  Requires SAT solver.  See
   465 src/HOL/ex/Termination.thy for examples.
   466 
   467 * Simplifier: simproc for let expressions now unfolds if bound
   468 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   469 
   470 * Method "arith": Linear arithmetic now ignores all inequalities when
   471 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   472 
   473 * New attribute "arith" for facts that should always be used
   474 automatically by arithmetic. It is intended to be used locally in
   475 proofs, e.g.
   476 
   477   assumes [arith]: "x > 0"
   478 
   479 Global usage is discouraged because of possible performance impact.
   480 
   481 * New classes "top" and "bot" with corresponding operations "top" and
   482 "bot" in theory Orderings; instantiation of class "complete_lattice"
   483 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   484 
   485 * Changed definition lemma "less_fun_def" in order to provide an
   486 instance for preorders on functions; use lemma "less_le" instead.
   487 INCOMPATIBILITY.
   488 
   489 * Theory Orderings: class "wellorder" moved here, with explicit
   490 induction rule "less_induct" as assumption.  For instantiation of
   491 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   492 INCOMPATIBILITY.
   493 
   494 * Theory Orderings: added class "preorder" as superclass of "order".
   495 INCOMPATIBILITY: Instantiation proofs for order, linorder
   496 etc. slightly changed.  Some theorems named order_class.* now named
   497 preorder_class.*.
   498 
   499 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   500 "diag" to "Id_on".
   501 
   502 * Theory Finite_Set: added a new fold combinator of type
   503 
   504   ('a => 'b => 'b) => 'b => 'a set => 'b
   505 
   506 Occasionally this is more convenient than the old fold combinator
   507 which is now defined in terms of the new one and renamed to
   508 fold_image.
   509 
   510 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   511 and "ring_simps" have been replaced by "algebra_simps" (which can be
   512 extended with further lemmas!).  At the moment both still exist but
   513 the former will disappear at some point.
   514 
   515 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   516 class recpower.  Type-specific simp rules for various recpower types
   517 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   518 
   519 rat_power_0    -> power_0
   520 rat_power_Suc  -> power_Suc
   521 realpow_0      -> power_0
   522 realpow_Suc    -> power_Suc
   523 complexpow_0   -> power_0
   524 complexpow_Suc -> power_Suc
   525 power_poly_0   -> power_0
   526 power_poly_Suc -> power_Suc
   527 
   528 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   529 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   530 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   531 of lemmas from Divides has been generalized from nat to class
   532 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   533 renames resulting from duplicate elimination:
   534 
   535     dvd_def_mod ~>          dvd_eq_mod_eq_0
   536     zero_dvd_iff ~>         dvd_0_left_iff
   537     dvd_0 ~>                dvd_0_right
   538     DIVISION_BY_ZERO_DIV ~> div_by_0
   539     DIVISION_BY_ZERO_MOD ~> mod_by_0
   540     mult_div ~>             div_mult_self2_is_id
   541     mult_mod ~>             mod_mult_self2_is_0
   542 
   543 * Theory IntDiv: removed many lemmas that are instances of class-based
   544 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   545 rename old lemmas as follows:
   546 
   547 dvd_diff               -> nat_dvd_diff
   548 dvd_zminus_iff         -> dvd_minus_iff
   549 mod_add1_eq            -> mod_add_eq
   550 mod_mult1_eq           -> mod_mult_right_eq
   551 mod_mult1_eq'          -> mod_mult_left_eq
   552 mod_mult_distrib_mod   -> mod_mult_eq
   553 nat_mod_add_left_eq    -> mod_add_left_eq
   554 nat_mod_add_right_eq   -> mod_add_right_eq
   555 nat_mod_div_trivial    -> mod_div_trivial
   556 nat_mod_mod_trivial    -> mod_mod_trivial
   557 zdiv_zadd_self1        -> div_add_self1
   558 zdiv_zadd_self2        -> div_add_self2
   559 zdiv_zmult_self1       -> div_mult_self2_is_id
   560 zdiv_zmult_self2       -> div_mult_self1_is_id
   561 zdvd_triv_left         -> dvd_triv_left
   562 zdvd_triv_right        -> dvd_triv_right
   563 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   564 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   565 zmod_zadd_left_eq      -> mod_add_left_eq
   566 zmod_zadd_right_eq     -> mod_add_right_eq
   567 zmod_zadd_self1        -> mod_add_self1
   568 zmod_zadd_self2        -> mod_add_self2
   569 zmod_zadd1_eq          -> mod_add_eq
   570 zmod_zdiff1_eq         -> mod_diff_eq
   571 zmod_zdvd_zmod         -> mod_mod_cancel
   572 zmod_zmod_cancel       -> mod_mod_cancel
   573 zmod_zmult_self1       -> mod_mult_self2_is_0
   574 zmod_zmult_self2       -> mod_mult_self1_is_0
   575 zmod_1                 -> mod_by_1
   576 zdiv_1                 -> div_by_1
   577 zdvd_abs1              -> abs_dvd_iff
   578 zdvd_abs2              -> dvd_abs_iff
   579 zdvd_refl              -> dvd_refl
   580 zdvd_trans             -> dvd_trans
   581 zdvd_zadd              -> dvd_add
   582 zdvd_zdiff             -> dvd_diff
   583 zdvd_zminus_iff        -> dvd_minus_iff
   584 zdvd_zminus2_iff       -> minus_dvd_iff
   585 zdvd_zmultD            -> dvd_mult_right
   586 zdvd_zmultD2           -> dvd_mult_left
   587 zdvd_zmult_mono        -> mult_dvd_mono
   588 zdvd_0_right           -> dvd_0_right
   589 zdvd_0_left            -> dvd_0_left_iff
   590 zdvd_1_left            -> one_dvd
   591 zminus_dvd_iff         -> minus_dvd_iff
   592 
   593 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   594 
   595 * The real numbers offer decimal input syntax: 12.34 is translated
   596 into 1234/10^2. This translation is not reversed upon output.
   597 
   598 * Theory Library/Polynomial defines an abstract type 'a poly of
   599 univariate polynomials with coefficients of type 'a.  In addition to
   600 the standard ring operations, it also supports div and mod.  Code
   601 generation is also supported, using list-style constructors.
   602 
   603 * Theory Library/Inner_Product defines a class of real_inner for real
   604 inner product spaces, with an overloaded operation inner :: 'a => 'a
   605 => real.  Class real_inner is a subclass of real_normed_vector from
   606 theory RealVector.
   607 
   608 * Theory Library/Product_Vector provides instances for the product
   609 type 'a * 'b of several classes from RealVector and Inner_Product.
   610 Definitions of addition, subtraction, scalar multiplication, norms,
   611 and inner products are included.
   612 
   613 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   614 addition to the field operations, numerals and case syntax are also
   615 supported.
   616 
   617 * Theory Library/Diagonalize provides constructive version of Cantor's
   618 first diagonalization argument.
   619 
   620 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   621 zlcm (for int); carried together from various gcd/lcm developements in
   622 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   623 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   624 may recover tupled syntax as follows:
   625 
   626     hide (open) const gcd
   627     abbreviation gcd where
   628       "gcd == (%(a, b). GCD.gcd a b)"
   629     notation (output)
   630       GCD.gcd ("gcd '(_, _')")
   631 
   632 The same works for lcm, zgcd, zlcm.
   633 
   634 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   635 instantiations for algebraic structures.  Removed some duplicate
   636 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   637 
   638 * ML antiquotation @{code} takes a constant as argument and generates
   639 corresponding code in background and inserts name of the corresponding
   640 resulting ML value/function/datatype constructor binding in place.
   641 All occurrences of @{code} with a single ML block are generated
   642 simultaneously.  Provides a generic and safe interface for
   643 instrumentalizing code generation.  See
   644 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   645 In future you ought to refrain from ad-hoc compiling generated SML
   646 code on the ML toplevel.  Note that (for technical reasons) @{code}
   647 cannot refer to constants for which user-defined serializations are
   648 set.  Refer to the corresponding ML counterpart directly in that
   649 cases.
   650 
   651 * Command 'rep_datatype': instead of theorem names the command now
   652 takes a list of terms denoting the constructors of the type to be
   653 represented as datatype.  The characteristic theorems have to be
   654 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   655 have disappeared in favour of existing ones:
   656 
   657     unit_induct                 ~> unit.induct
   658     prod_induct                 ~> prod.induct
   659     sum_induct                  ~> sum.induct
   660     Suc_Suc_eq                  ~> nat.inject
   661     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   662 
   663 
   664 *** HOL-Algebra ***
   665 
   666 * New locales for orders and lattices where the equivalence relation
   667 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   668 locales use a record structure with field eq for the equivalence.
   669 
   670 * New theory of factorial domains.
   671 
   672 * Units_l_inv and Units_r_inv are now simp rules by default.
   673 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   674 and/or r_inv will now also require deletion of these lemmas.
   675 
   676 * Renamed the following theorems, INCOMPATIBILITY:
   677 
   678 UpperD ~> Upper_memD
   679 LowerD ~> Lower_memD
   680 least_carrier ~> least_closed
   681 greatest_carrier ~> greatest_closed
   682 greatest_Lower_above ~> greatest_Lower_below
   683 one_zero ~> carrier_one_zero
   684 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   685 
   686 
   687 *** HOL-Nominal ***
   688 
   689 * Nominal datatypes can now contain type-variables.
   690 
   691 * Commands 'nominal_inductive' and 'equivariance' work with local
   692 theory targets.
   693 
   694 * Nominal primrec can now works with local theory targets and its
   695 specification syntax now conforms to the general format as seen in
   696 'inductive' etc.
   697 
   698 * Method "perm_simp" honours the standard simplifier attributes
   699 (no_asm), (no_asm_use) etc.
   700 
   701 * The new predicate #* is defined like freshness, except that on the
   702 left hand side can be a set or list of atoms.
   703 
   704 * Experimental command 'nominal_inductive2' derives strong induction
   705 principles for inductive definitions.  In contrast to
   706 'nominal_inductive', which can only deal with a fixed number of
   707 binders, it can deal with arbitrary expressions standing for sets of
   708 atoms to be avoided.  The only inductive definition we have at the
   709 moment that needs this generalisation is the typing rule for Lets in
   710 the algorithm W:
   711 
   712  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   713  -----------------------------------------------------------------
   714          Gamma |- Let x be t1 in t2 : T2
   715 
   716 In this rule one wants to avoid all the binders that are introduced by
   717 "close Gamma T1".  We are looking for other examples where this
   718 feature might be useful.  Please let us know.
   719 
   720 
   721 *** HOLCF ***
   722 
   723 * Reimplemented the simplification procedure for proving continuity
   724 subgoals.  The new simproc is extensible; users can declare additional
   725 continuity introduction rules with the attribute [cont2cont].
   726 
   727 * The continuity simproc now uses a different introduction rule for
   728 solving continuity subgoals on terms with lambda abstractions.  In
   729 some rare cases the new simproc may fail to solve subgoals that the
   730 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   731 Potential INCOMPATIBILITY.
   732 
   733 * Command 'fixrec': specification syntax now conforms to the general
   734 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   735 examples.  INCOMPATIBILITY.
   736 
   737 
   738 *** ZF ***
   739 
   740 * Proof of Zorn's Lemma for partial orders.
   741 
   742 
   743 *** ML ***
   744 
   745 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   746 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   747 depends on multithreading, so timouts will not work before Poly/ML
   748 5.2.1!
   749 
   750 * High-level support for concurrent ML programming, see
   751 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   752 particularly convenient to organize independent functional
   753 computations.  The concept of "synchronized variables" provides a
   754 higher-order interface for components with shared state, avoiding the
   755 delicate details of mutexes and condition variables.  (Requires
   756 Poly/ML 5.2.1 or later.)
   757 
   758 * ML bindings produced via Isar commands are stored within the Isar
   759 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   760 become thread-safe and work with undo as expected (concerning
   761 top-level bindings, not side-effects on global references).
   762 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   763 compiler at runtime; really global bindings need to be given outside a
   764 theory.  (Requires Poly/ML 5.2 or later.)
   765 
   766 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   767 context.  Top-level ML bindings are stored within the proof context in
   768 a purely sequential fashion, disregarding the nested proof structure.
   769 ML bindings introduced by 'ML_prf' are discarded at the end of the
   770 proof.  (Requires Poly/ML 5.2 or later.)
   771 
   772 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   773 and Method.setup, as well as Isar commands 'attribute_setup' and
   774 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   775 existing code accordingly, or use plain 'setup' together with old
   776 Method.add_method.
   777 
   778 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   779 to 'a -> thm, while results are always tagged with an authentic oracle
   780 name.  The Isar command 'oracle' is now polymorphic, no argument type
   781 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   782 accordingly.  Note that extra performance may be gained by producing
   783 the cterm carefully, avoiding slow Thm.cterm_of.
   784 
   785 * Simplified interface for defining document antiquotations via
   786 ThyOutput.antiquotation, ThyOutput.output, and optionally
   787 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   788 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   789 examples.
   790 
   791 * More systematic treatment of long names, abstract name bindings, and
   792 name space operations.  Basic operations on qualified names have been
   793 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   794 Long_Name.append.  Old type bstring has been mostly replaced by
   795 abstract type binding (see structure Binding), which supports precise
   796 qualification by packages and local theory targets, as well as proper
   797 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   798 bstring values into Binding.name, or better pass through abstract
   799 bindings everywhere.  See further src/Pure/General/long_name.ML,
   800 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   801 
   802 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   803 LocalTheory.note etc.) now refer to the *full* internal name, not the
   804 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   805 
   806 * Disposed old type and term read functions (Sign.read_def_typ,
   807 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   808 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   809 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   810 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   811 resort for legacy applications.
   812 
   813 * Disposed old declarations, tactics, tactic combinators that refer to
   814 the simpset or claset of an implicit theory (such as Addsimps,
   815 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   816 embedded ML text, or local_simpset_of with a proper context passed as
   817 explicit runtime argument.
   818 
   819 * Rules and tactics that read instantiations (read_instantiate,
   820 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   821 context, which is required for parsing and type-checking.  Moreover,
   822 the variables are specified as plain indexnames, not string encodings
   823 thereof.  INCOMPATIBILITY.
   824 
   825 * Generic Toplevel.add_hook interface allows to analyze the result of
   826 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   827 for theorem dependency output of transactions resulting in a new
   828 theory state.
   829 
   830 * ML antiquotations: block-structured compilation context indicated by
   831 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   832 
   833   @{binding name}                         - basic name binding
   834   @{let ?pat = term}                      - term abbreviation (HO matching)
   835   @{note name = fact}                     - fact abbreviation
   836   @{thm fact}                             - singleton fact (with attributes)
   837   @{thms fact}                            - general fact (with attributes)
   838   @{lemma prop by method}                 - singleton goal
   839   @{lemma prop by meth1 meth2}            - singleton goal
   840   @{lemma prop1 ... propN by method}      - general goal
   841   @{lemma prop1 ... propN by meth1 meth2} - general goal
   842   @{lemma (open) ...}                     - open derivation
   843 
   844 
   845 *** System ***
   846 
   847 * The Isabelle "emacs" tool provides a specific interface to invoke
   848 Proof General / Emacs, with more explicit failure if that is not
   849 installed (the old isabelle-interface script silently falls back on
   850 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   851 installation location of the Proof General distribution.
   852 
   853 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   854 the Isabelle process into a JVM/Scala application.  See
   855 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   856 process wrapper has been discontinued.)
   857 
   858 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   859 
   860 * Various status messages (with exact source position information) are
   861 emitted, if proper markup print mode is enabled.  This allows
   862 user-interface components to provide detailed feedback on internal
   863 prover operations.
   864 
   865 
   866 
   867 New in Isabelle2008 (June 2008)
   868 -------------------------------
   869 
   870 *** General ***
   871 
   872 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   873 and updated, with formally checked references as hyperlinks.
   874 
   875 * Theory loader: use_thy (and similar operations) no longer set the
   876 implicit ML context, which was occasionally hard to predict and in
   877 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   878 provides a proper context already.
   879 
   880 * Theory loader: old-style ML proof scripts being *attached* to a thy
   881 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   882 'use' within a theory file will do the job.
   883 
   884 * Name space merge now observes canonical order, i.e. the second space
   885 is inserted into the first one, while existing entries in the first
   886 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   887 swap theory imports.
   888 
   889 * Syntax: symbol \<chi> is now considered a letter.  Potential
   890 INCOMPATIBILITY in identifier syntax etc.
   891 
   892 * Outer syntax: string tokens no longer admit escaped white space,
   893 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   894 white space without escapes.
   895 
   896 * Outer syntax: string tokens may contain arbitrary character codes
   897 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   898 "foo_bar".
   899 
   900 
   901 *** Pure ***
   902 
   903 * Context-dependent token translations.  Default setup reverts locally
   904 fixed variables, and adds hilite markup for undeclared frees.
   905 
   906 * Unused theorems can be found using the new command 'unused_thms'.
   907 There are three ways of invoking it:
   908 
   909 (1) unused_thms
   910      Only finds unused theorems in the current theory.
   911 
   912 (2) unused_thms thy_1 ... thy_n -
   913      Finds unused theorems in the current theory and all of its ancestors,
   914      excluding the theories thy_1 ... thy_n and all of their ancestors.
   915 
   916 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   917      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   918      their ancestors, excluding the theories thy_1 ... thy_n and all of
   919      their ancestors.
   920 
   921 In order to increase the readability of the list produced by
   922 unused_thms, theorems that have been created by a particular instance
   923 of a theory command such as 'inductive' or 'function' are considered
   924 to belong to the same "group", meaning that if at least one theorem in
   925 this group is used, the other theorems in the same group are no longer
   926 reported as unused.  Moreover, if all theorems in the group are
   927 unused, only one theorem in the group is displayed.
   928 
   929 Note that proof objects have to be switched on in order for
   930 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   931 usually the case when using Proof General with the default settings).
   932 
   933 * Authentic naming of facts disallows ad-hoc overwriting of previous
   934 theorems within the same name space.  INCOMPATIBILITY, need to remove
   935 duplicate fact bindings, or even accidental fact duplications.  Note
   936 that tools may maintain dynamically scoped facts systematically, using
   937 PureThy.add_thms_dynamic.
   938 
   939 * Command 'hide' now allows to hide from "fact" name space as well.
   940 
   941 * Eliminated destructive theorem database, simpset, claset, and
   942 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   943 update of theories within ML code.
   944 
   945 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   946 INCOMPATIBILITY, object-logics depending on former Pure require
   947 additional setup PureThy.old_appl_syntax_setup; object-logics
   948 depending on former CPure need to refer to Pure.
   949 
   950 * Commands 'use' and 'ML' are now purely functional, operating on
   951 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
   952 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
   953 INCOMPATIBILITY.
   954 
   955 * Command 'setup': discontinued implicit version with ML reference.
   956 
   957 * Instantiation target allows for simultaneous specification of class
   958 instance operations together with an instantiation proof.
   959 Type-checking phase allows to refer to class operations uniformly.
   960 See src/HOL/Complex/Complex.thy for an Isar example and
   961 src/HOL/Library/Eval.thy for an ML example.
   962 
   963 * Indexing of literal facts: be more serious about including only
   964 facts from the visible specification/proof context, but not the
   965 background context (locale etc.).  Affects `prop` notation and method
   966 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
   967 situations.
   968 
   969 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   970 "(open)" option, which used to expose internal bound variables to the
   971 proof text.
   972 
   973 * Isar statements: removed obsolete case "rule_context".
   974 INCOMPATIBILITY, better use explicit fixes/assumes.
   975 
   976 * Locale proofs: default proof step now includes 'unfold_locales';
   977 hence 'proof' without argument may be used to unfold locale
   978 predicates.
   979 
   980 
   981 *** Document preparation ***
   982 
   983 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   984 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   985 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   986 spot); renamed link color from "darkblue" to "linkcolor" (default
   987 value unchanged, can be redefined via \definecolor); no longer sets
   988 "a4paper" option (unnecessary or even intrusive).
   989 
   990 * Antiquotation @{lemma A method} proves proposition A by the given
   991 method (either a method name or a method name plus (optional) method
   992 arguments in parentheses) and prints A just like @{prop A}.
   993 
   994 
   995 *** HOL ***
   996 
   997 * New primrec package.  Specification syntax conforms in style to
   998 definition/function/....  No separate induction rule is provided.  The
   999 "primrec" command distinguishes old-style and new-style specifications
  1000 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1001 When adjusting theories, beware: constants stemming from new-style
  1002 primrec specifications have authentic syntax.
  1003 
  1004 * Metis prover is now an order of magnitude faster, and also works
  1005 with multithreading.
  1006 
  1007 * Metis: the maximum number of clauses that can be produced from a
  1008 theorem is now given by the attribute max_clauses.  Theorems that
  1009 exceed this number are ignored, with a warning printed.
  1010 
  1011 * Sledgehammer no longer produces structured proofs by default. To
  1012 enable, declare [[sledgehammer_full = true]].  Attributes
  1013 reconstruction_modulus, reconstruction_sorts renamed
  1014 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1015 
  1016 * Method "induct_scheme" derives user-specified induction rules
  1017 from well-founded induction and completeness of patterns. This factors
  1018 out some operations that are done internally by the function package
  1019 and makes them available separately.  See
  1020 src/HOL/ex/Induction_Scheme.thy for examples.
  1021 
  1022 * More flexible generation of measure functions for termination
  1023 proofs: Measure functions can be declared by proving a rule of the
  1024 form "is_measure f" and giving it the [measure_function] attribute.
  1025 The "is_measure" predicate is logically meaningless (always true), and
  1026 just guides the heuristic.  To find suitable measure functions, the
  1027 termination prover sets up the goal "is_measure ?f" of the appropriate
  1028 type and generates all solutions by prolog-style backwards proof using
  1029 the declared rules.
  1030 
  1031 This setup also deals with rules like 
  1032 
  1033   "is_measure f ==> is_measure (list_size f)"
  1034 
  1035 which accommodates nested datatypes that recurse through lists.
  1036 Similar rules are predeclared for products and option types.
  1037 
  1038 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1039 
  1040   INCOMPATIBILITIES:
  1041 
  1042   - Definitions of overloaded constants on sets have to be replaced by
  1043     definitions on => and bool.
  1044 
  1045   - Some definitions of overloaded operators on sets can now be proved
  1046     using the definitions of the operators on => and bool.  Therefore,
  1047     the following theorems have been renamed:
  1048 
  1049       subset_def   -> subset_eq
  1050       psubset_def  -> psubset_eq
  1051       set_diff_def -> set_diff_eq
  1052       Compl_def    -> Compl_eq
  1053       Sup_set_def  -> Sup_set_eq
  1054       Inf_set_def  -> Inf_set_eq
  1055       sup_set_def  -> sup_set_eq
  1056       inf_set_def  -> inf_set_eq
  1057 
  1058   - Due to the incompleteness of the HO unification algorithm, some
  1059     rules such as subst may require manual instantiation, if some of
  1060     the unknowns in the rule is a set.
  1061 
  1062   - Higher order unification and forward proofs:
  1063     The proof pattern
  1064 
  1065       have "P (S::'a set)" <...>
  1066       then have "EX S. P S" ..
  1067 
  1068     no longer works (due to the incompleteness of the HO unification
  1069     algorithm) and must be replaced by the pattern
  1070 
  1071       have "EX S. P S"
  1072       proof
  1073         show "P S" <...>
  1074       qed
  1075 
  1076   - Calculational reasoning with subst (or similar rules):
  1077     The proof pattern
  1078 
  1079       have "P (S::'a set)" <...>
  1080       also have "S = T" <...>
  1081       finally have "P T" .
  1082 
  1083     no longer works (for similar reasons as the previous example) and
  1084     must be replaced by something like
  1085 
  1086       have "P (S::'a set)" <...>
  1087       moreover have "S = T" <...>
  1088       ultimately have "P T" by simp
  1089 
  1090   - Tactics or packages written in ML code:
  1091     Code performing pattern matching on types via
  1092 
  1093       Type ("set", [T]) => ...
  1094 
  1095     must be rewritten. Moreover, functions like strip_type or
  1096     binder_types no longer return the right value when applied to a
  1097     type of the form
  1098 
  1099       T1 => ... => Tn => U => bool
  1100 
  1101     rather than
  1102 
  1103       T1 => ... => Tn => U set
  1104 
  1105 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1106 Wellfounded_Relations to theory Wellfounded.
  1107 
  1108 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1109 
  1110 * Class finite no longer treats UNIV as class parameter.  Use class
  1111 enum from theory Library/Enum instead to achieve a similar effect.
  1112 INCOMPATIBILITY.
  1113 
  1114 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1115 and "Cons".  INCOMPATIBILITY.
  1116 
  1117 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1118 Potential INCOMPATIBILITY.
  1119 
  1120 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1121 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1122 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1123 
  1124 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1125 the same name in theory Orderings:
  1126 
  1127   less_trans
  1128   less_linear
  1129   le_imp_less_or_eq
  1130   le_less_trans
  1131   less_le_trans
  1132   less_not_sym
  1133   less_asym
  1134 
  1135 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1136 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1137 and different variable names.
  1138 
  1139 * Library/Option_ord.thy: Canonical order on option type.
  1140 
  1141 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1142 finite maps.
  1143 
  1144 * Library/Countable.thy: Type class for countable types.
  1145 
  1146 * Theory Int: The representation of numerals has changed.  The infix
  1147 operator BIT and the bit datatype with constructors B0 and B1 have
  1148 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1149 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1150 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1151 accordingly.
  1152 
  1153 * Theory Nat: definition of <= and < on natural numbers no longer
  1154 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1155 le_def and less_def have disappeared.  Consider lemmas not_less
  1156 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1157 
  1158 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1159 (whose purpose mainly is for various fold_set functionals) have been
  1160 abandoned in favor of the existing algebraic classes
  1161 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1162 lower_semilattice (resp. upper_semilattice) and linorder.
  1163 INCOMPATIBILITY.
  1164 
  1165 * Theory Transitive_Closure: induct and cases rules now declare proper
  1166 case_names ("base" and "step").  INCOMPATIBILITY.
  1167 
  1168 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1169 lattices.  The form set-specific version is available as
  1170 Inductive.lfp_ordinal_induct_set.
  1171 
  1172 * Renamed theorems "power.simps" to "power_int.simps".
  1173 INCOMPATIBILITY.
  1174 
  1175 * Class semiring_div provides basic abstract properties of semirings
  1176 with division and modulo operations.  Subsumes former class dvd_mod.
  1177 
  1178 * Merged theories IntDef, Numeral and IntArith into unified theory
  1179 Int.  INCOMPATIBILITY.
  1180 
  1181 * Theory Library/Code_Index: type "index" now represents natural
  1182 numbers rather than integers.  INCOMPATIBILITY.
  1183 
  1184 * New class "uminus" with operation "uminus" (split of from class
  1185 "minus" which now only has operation "minus", binary).
  1186 INCOMPATIBILITY.
  1187 
  1188 * Constants "card", "internal_split", "option_map" now with authentic
  1189 syntax.  INCOMPATIBILITY.
  1190 
  1191 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1192 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1193 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1194 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1195 Sup_set_def, le_def, less_def, option_map_def now with object
  1196 equality.  INCOMPATIBILITY.
  1197 
  1198 * Records. Removed K_record, and replaced it by pure lambda term
  1199 %x. c. The simplifier setup is now more robust against eta expansion.
  1200 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1201 
  1202 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1203 
  1204 * Library/ListVector: new theory of arithmetic vector operations.
  1205 
  1206 * Library/Order_Relation: new theory of various orderings as sets of
  1207 pairs.  Defines preorders, partial orders, linear orders and
  1208 well-orders on sets and on types.
  1209 
  1210 
  1211 *** ZF ***
  1212 
  1213 * Renamed some theories to allow to loading both ZF and HOL in the
  1214 same session:
  1215 
  1216   Datatype  -> Datatype_ZF
  1217   Inductive -> Inductive_ZF
  1218   Int       -> Int_ZF
  1219   IntDiv    -> IntDiv_ZF
  1220   Nat       -> Nat_ZF
  1221   List      -> List_ZF
  1222   Main      -> Main_ZF
  1223 
  1224 INCOMPATIBILITY: ZF theories that import individual theories below
  1225 Main might need to be adapted.  Regular theory Main is still
  1226 available, as trivial extension of Main_ZF.
  1227 
  1228 
  1229 *** ML ***
  1230 
  1231 * ML within Isar: antiquotation @{const name} or @{const
  1232 name(typargs)} produces statically-checked Const term.
  1233 
  1234 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1235 (of the same name).  Removed obsolete print command.
  1236 
  1237 * Removed obsolete "use_legacy_bindings" function.
  1238 
  1239 * The ``print mode'' is now a thread-local value derived from a global
  1240 template (the former print_mode reference), thus access becomes
  1241 non-critical.  The global print_mode reference is for session
  1242 management only; user-code should use print_mode_value,
  1243 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1244 
  1245 * Functions system/system_out provide a robust way to invoke external
  1246 shell commands, with propagation of interrupts (requires Poly/ML
  1247 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1248 
  1249 
  1250 *** System ***
  1251 
  1252 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1253 in accordance with Proof General 3.7, which prefers GNU emacs.
  1254 
  1255 * isatool tty runs Isabelle process with plain tty interaction;
  1256 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1257 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1258 
  1259 * isatool browser now works with Cygwin as well, using general
  1260 "javapath" function defined in Isabelle process environment.
  1261 
  1262 * YXML notation provides a simple and efficient alternative to
  1263 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1264 isatool yxml as described in the Isabelle system manual.
  1265 
  1266 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1267 provides general wrapper for managing an Isabelle process in a robust
  1268 fashion, with ``cooked'' output from stdin/stderr.
  1269 
  1270 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1271 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1272 
  1273 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1274 way of changing the user's settings is via
  1275 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1276 script.
  1277 
  1278 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1279 cores of the underlying machine, which is a good starting point for
  1280 optimal performance tuning.  The corresponding usedir option -M allows
  1281 "max" as an alias for "0".  WARNING: does not work on certain versions
  1282 of Mac OS (with Poly/ML 5.1).
  1283 
  1284 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1285 adverse effect of Isabelle flooding interactive front-ends (notably
  1286 ProofGeneral / XEmacs).
  1287 
  1288 
  1289 
  1290 New in Isabelle2007 (November 2007)
  1291 -----------------------------------
  1292 
  1293 *** General ***
  1294 
  1295 * More uniform information about legacy features, notably a
  1296 warning/error of "Legacy feature: ...", depending on the state of the
  1297 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1298 legacy features will disappear eventually.
  1299 
  1300 * Theory syntax: the header format ``theory A = B + C:'' has been
  1301 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1302 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1303 
  1304 * Theory syntax: the old non-Isar theory file format has been
  1305 discontinued altogether.  Note that ML proof scripts may still be used
  1306 with Isar theories; migration is usually quite simple with the ML
  1307 function use_legacy_bindings.  INCOMPATIBILITY.
  1308 
  1309 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1310 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1311 quotes.
  1312 
  1313 * Theory loader: be more serious about observing the static theory
  1314 header specifications (including optional directories), but not the
  1315 accidental file locations of previously successful loads.  The strict
  1316 update policy of former update_thy is now already performed by
  1317 use_thy, so the former has been removed; use_thys updates several
  1318 theories simultaneously, just as 'imports' within a theory header
  1319 specification, but without merging the results.  Potential
  1320 INCOMPATIBILITY: may need to refine theory headers and commands
  1321 ROOT.ML which depend on load order.
  1322 
  1323 * Theory loader: optional support for content-based file
  1324 identification, instead of the traditional scheme of full physical
  1325 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1326 (cf. the system manual).  The new scheme allows to work with
  1327 non-finished theories in persistent session images, such that source
  1328 files may be moved later on without requiring reloads.
  1329 
  1330 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1331 file (with the same base name as the theory) are considered a legacy
  1332 feature, which will disappear eventually. Even now, the theory loader
  1333 no longer maintains dependencies on such files.
  1334 
  1335 * Syntax: the scope for resolving ambiguities via type-inference is
  1336 now limited to individual terms, instead of whole simultaneous
  1337 specifications as before. This greatly reduces the complexity of the
  1338 syntax module and improves flexibility by separating parsing and
  1339 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1340 'fixes' etc.) are required in rare situations.
  1341 
  1342 * Syntax: constants introduced by new-style packages ('definition',
  1343 'abbreviation' etc.) are passed through the syntax module in
  1344 ``authentic mode''. This means that associated mixfix annotations
  1345 really stick to such constants, independently of potential name space
  1346 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1347 trees are represented slightly differently, may need to adapt syntax
  1348 translations accordingly. Use CONST marker in 'translations' and
  1349 @{const_syntax} antiquotation in 'parse_translation' etc.
  1350 
  1351 * Legacy goal package: reduced interface to the bare minimum required
  1352 to keep existing proof scripts running.  Most other user-level
  1353 functions are now part of the OldGoals structure, which is *not* open
  1354 by default (consider isatool expandshort before open OldGoals).
  1355 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1356 these tend to cause confusion about the actual goal (!) context being
  1357 used here, which is not necessarily the same as the_context().
  1358 
  1359 * Command 'find_theorems': supports "*" wild-card in "name:"
  1360 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1361 support a specific search form (see ProofGeneral/CHANGES).
  1362 
  1363 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1364 by default, which means that "prems" (and also "fixed variables") are
  1365 suppressed from proof state output.  Note that the ProofGeneral
  1366 settings mechanism allows to change and save options persistently, but
  1367 older versions of Isabelle will fail to start up if a negative prems
  1368 limit is imposed.
  1369 
  1370 * Local theory targets may be specified by non-nested blocks of
  1371 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1372 contain definitions, theorems etc., including any derived mechanism
  1373 that has been implemented on top of these primitives.  This concept
  1374 generalizes the existing ``theorem (in ...)'' towards more versatility
  1375 and scalability.
  1376 
  1377 * Proof General interface: proper undo of final 'end' command;
  1378 discontinued Isabelle/classic mode (ML proof scripts).
  1379 
  1380 
  1381 *** Document preparation ***
  1382 
  1383 * Added antiquotation @{theory name} which prints the given name,
  1384 after checking that it refers to a valid ancestor theory in the
  1385 current context.
  1386 
  1387 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1388 check the given source text as ML type/structure, printing verbatim.
  1389 
  1390 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1391 "c args == rhs" given in the current context.  (Any number of
  1392 arguments may be given on the LHS.)
  1393 
  1394 
  1395 *** Pure ***
  1396 
  1397 * The 'class' package offers a combination of axclass and locale to
  1398 achieve Haskell-like type classes in Isabelle.  Definitions and
  1399 theorems within a class context produce both relative results (with
  1400 implicit parameters according to the locale context), and polymorphic
  1401 constants with qualified polymorphism (according to the class
  1402 context).  Within the body context of a 'class' target, a separate
  1403 syntax layer ("user space type system") takes care of converting
  1404 between global polymorphic consts and internal locale representation.
  1405 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1406 "isatool doc classes" provides a tutorial.
  1407 
  1408 * Generic code generator framework allows to generate executable
  1409 code for ML and Haskell (including Isabelle classes).  A short usage
  1410 sketch:
  1411 
  1412     internal compilation:
  1413         export_code <list of constants (term syntax)> in SML
  1414     writing SML code to a file:
  1415         export_code <list of constants (term syntax)> in SML <filename>
  1416     writing OCaml code to a file:
  1417         export_code <list of constants (term syntax)> in OCaml <filename>
  1418     writing Haskell code to a bunch of files:
  1419         export_code <list of constants (term syntax)> in Haskell <filename>
  1420 
  1421     evaluating closed propositions to True/False using code generation:
  1422         method ``eval''
  1423 
  1424 Reasonable default setup of framework in HOL.
  1425 
  1426 Theorem attributs for selecting and transforming function equations theorems:
  1427 
  1428     [code fun]:        select a theorem as function equation for a specific constant
  1429     [code fun del]:    deselect a theorem as function equation for a specific constant
  1430     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1431     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1432 
  1433 User-defined serializations (target in {SML, OCaml, Haskell}):
  1434 
  1435     code_const <and-list of constants (term syntax)>
  1436       {(target) <and-list of const target syntax>}+
  1437 
  1438     code_type <and-list of type constructors>
  1439       {(target) <and-list of type target syntax>}+
  1440 
  1441     code_instance <and-list of instances>
  1442       {(target)}+
  1443         where instance ::= <type constructor> :: <class>
  1444 
  1445     code_class <and_list of classes>
  1446       {(target) <and-list of class target syntax>}+
  1447         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1448 
  1449 code_instance and code_class only are effective to target Haskell.
  1450 
  1451 For example usage see src/HOL/ex/Codegenerator.thy and
  1452 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1453 generation from Isabelle/HOL theories is available via "isatool doc
  1454 codegen".
  1455 
  1456 * Code generator: consts in 'consts_code' Isar commands are now
  1457 referred to by usual term syntax (including optional type
  1458 annotations).
  1459 
  1460 * Command 'no_translations' removes translation rules from theory
  1461 syntax.
  1462 
  1463 * Overloaded definitions are now actually checked for acyclic
  1464 dependencies.  The overloading scheme is slightly more general than
  1465 that of Haskell98, although Isabelle does not demand an exact
  1466 correspondence to type class and instance declarations.
  1467 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1468 exotic versions of overloading -- at the discretion of the user!
  1469 
  1470 Polymorphic constants are represented via type arguments, i.e. the
  1471 instantiation that matches an instance against the most general
  1472 declaration given in the signature.  For example, with the declaration
  1473 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1474 as c(nat).  Overloading is essentially simultaneous structural
  1475 recursion over such type arguments.  Incomplete specification patterns
  1476 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1477 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1478 Command 'print_theory' outputs the normalized system of recursive
  1479 equations, see section "definitions".
  1480 
  1481 * Configuration options are maintained within the theory or proof
  1482 context (with name and type bool/int/string), providing a very simple
  1483 interface to a poor-man's version of general context data.  Tools may
  1484 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1485 these values using Config.get etc.  Users may change options via an
  1486 associated attribute of the same name.  This form of context
  1487 declaration works particularly well with commands 'declare' or
  1488 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1489 very easy to avoid global references, which would not observe Isar
  1490 toplevel undo/redo and fail to work with multithreading.
  1491 
  1492 Various global ML references of Pure and HOL have been turned into
  1493 configuration options:
  1494 
  1495   Unify.search_bound		unify_search_bound
  1496   Unify.trace_bound		unify_trace_bound
  1497   Unify.trace_simp		unify_trace_simp
  1498   Unify.trace_types		unify_trace_types
  1499   Simplifier.simp_depth_limit	simp_depth_limit
  1500   Blast.depth_limit		blast_depth_limit
  1501   DatatypeProp.dtK		datatype_distinctness_limit
  1502   fast_arith_neq_limit  	fast_arith_neq_limit
  1503   fast_arith_split_limit	fast_arith_split_limit
  1504 
  1505 * Named collections of theorems may be easily installed as context
  1506 data using the functor NamedThmsFun (see also
  1507 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1508 attributes; there is also a toplevel print command.  This facility is
  1509 just a common case of general context data, which is the preferred way
  1510 for anything more complex than just a list of facts in canonical
  1511 order.
  1512 
  1513 * Isar: command 'declaration' augments a local theory by generic
  1514 declaration functions written in ML.  This enables arbitrary content
  1515 being added to the context, depending on a morphism that tells the
  1516 difference of the original declaration context wrt. the application
  1517 context encountered later on.
  1518 
  1519 * Isar: proper interfaces for simplification procedures.  Command
  1520 'simproc_setup' declares named simprocs (with match patterns, and body
  1521 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1522 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1523 
  1524 * Isar: an extra pair of brackets around attribute declarations
  1525 abbreviates a theorem reference involving an internal dummy fact,
  1526 which will be ignored later --- only the effect of the attribute on
  1527 the background context will persist.  This form of in-place
  1528 declarations is particularly useful with commands like 'declare' and
  1529 'using', for example ``have A using [[simproc a]] by simp''.
  1530 
  1531 * Isar: method "assumption" (and implicit closing of subproofs) now
  1532 takes simple non-atomic goal assumptions into account: after applying
  1533 an assumption as a rule the resulting subgoals are solved by atomic
  1534 assumption steps.  This is particularly useful to finish 'obtain'
  1535 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1536 without referring to the original premise "!!x. P x ==> thesis" in the
  1537 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1538 more permissive.
  1539 
  1540 * Isar: implicit use of prems from the Isar proof context is
  1541 considered a legacy feature.  Common applications like ``have A .''
  1542 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1543 referencing facts explicitly here improves readability and
  1544 maintainability of proof texts.
  1545 
  1546 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1547 the obtained context from the course of reasoning!  For example:
  1548 
  1549   assume "EX x y. A x & B y"   -- "any previous fact"
  1550   then guess x and y by clarify
  1551 
  1552 This technique is potentially adventurous, depending on the facts and
  1553 proof tools being involved here.
  1554 
  1555 * Isar: known facts from the proof context may be specified as literal
  1556 propositions, using ASCII back-quote syntax.  This works wherever
  1557 named facts used to be allowed so far, in proof commands, proof
  1558 methods, attributes etc.  Literal facts are retrieved from the context
  1559 according to unification of type and term parameters.  For example,
  1560 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1561 theorems in the current context, then these are valid literal facts:
  1562 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1563 
  1564 There is also a proof method "fact" which does the same composition
  1565 for explicit goal states, e.g. the following proof texts coincide with
  1566 certain special cases of literal facts:
  1567 
  1568   have "A" by fact                 ==  note `A`
  1569   have "A ==> B" by fact           ==  note `A ==> B`
  1570   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1571   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1572 
  1573 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1574 outer syntax.  Thus symbolic identifiers may be used without
  1575 additional white space in declarations like this: ``assume *: A''.
  1576 
  1577 * Isar: 'print_facts' prints all local facts of the current context,
  1578 both named and unnamed ones.
  1579 
  1580 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1581 
  1582   def x == "t" and y == "u"
  1583 
  1584 * Isar: added command 'unfolding', which is structurally similar to
  1585 'using', but affects both the goal state and facts by unfolding given
  1586 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1587 'unfolded' attribute may be replaced by first-class proof text.
  1588 
  1589 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1590 and command 'unfolding' now all support object-level equalities
  1591 (potentially conditional).  The underlying notion of rewrite rule is
  1592 analogous to the 'rule_format' attribute, but *not* that of the
  1593 Simplifier (which is usually more generous).
  1594 
  1595 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1596 premises of a theorem by n. Useful in conjunction with drule.
  1597 
  1598 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1599 method expression within a sandbox consisting of the first N
  1600 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1601 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1602 simplifies all new goals that emerge from applying rule foo to the
  1603 originally first one.
  1604 
  1605 * Isar: schematic goals are no longer restricted to higher-order
  1606 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1607 expected.
  1608 
  1609 * Isar: the conclusion of a long theorem statement is now either
  1610 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1611 (essentially a disjunction of cases with local parameters and
  1612 assumptions).  The latter allows to express general elimination rules
  1613 adequately; in this notation common elimination rules look like this:
  1614 
  1615   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1616     assumes "EX x. P x"
  1617     obtains x where "P x"
  1618 
  1619   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1620     assumes "A & B"
  1621     obtains A and B
  1622 
  1623   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1624     assumes "A | B"
  1625     obtains
  1626       A
  1627     | B
  1628 
  1629 The subsequent classical rules even refer to the formal "thesis"
  1630 explicitly:
  1631 
  1632   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1633     obtains "~ thesis"
  1634 
  1635   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1636     obtains "thesis ==> something"
  1637 
  1638 The actual proof of an 'obtains' statement is analogous to that of the
  1639 Isar proof element 'obtain', only that there may be several cases.
  1640 Optional case names may be specified in parentheses; these will be
  1641 available both in the present proof and as annotations in the
  1642 resulting rule, for later use with the 'cases' method (cf. attribute
  1643 case_names).
  1644 
  1645 * Isar: the assumptions of a long theorem statement are available as
  1646 "assms" fact in the proof context.  This is more appropriate than the
  1647 (historical) "prems", which refers to all assumptions of the current
  1648 context, including those from the target locale, proof body etc.
  1649 
  1650 * Isar: 'print_statement' prints theorems from the current theory or
  1651 proof context in long statement form, according to the syntax of a
  1652 top-level lemma.
  1653 
  1654 * Isar: 'obtain' takes an optional case name for the local context
  1655 introduction rule (default "that").
  1656 
  1657 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1658 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1659 to occur.
  1660 
  1661 * Pure: syntax "CONST name" produces a fully internalized constant
  1662 according to the current context.  This is particularly useful for
  1663 syntax translations that should refer to internal constant
  1664 representations independently of name spaces.
  1665 
  1666 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1667 instead of "FOO ". This allows multiple binder declarations to coexist
  1668 in the same context.  INCOMPATIBILITY.
  1669 
  1670 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1671 primitive that also works in a locale context (both for constants and
  1672 fixed variables). Type declaration and internal syntactic representation
  1673 of given constants retrieved from the context. Likewise, the
  1674 'no_notation' command allows to remove given syntax annotations from the
  1675 current context.
  1676 
  1677 * Isar/locales: new derived specification elements 'axiomatization',
  1678 'definition', 'abbreviation', which support type-inference, admit
  1679 object-level specifications (equality, equivalence).  See also the
  1680 isar-ref manual.  Examples:
  1681 
  1682   axiomatization
  1683     eq  (infix "===" 50) where
  1684     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1685 
  1686   definition "f x y = x + y + 1"
  1687   definition g where "g x = f x x"
  1688 
  1689   abbreviation
  1690     neq  (infix "=!=" 50) where
  1691     "x =!= y == ~ (x === y)"
  1692 
  1693 These specifications may be also used in a locale context.  Then the
  1694 constants being introduced depend on certain fixed parameters, and the
  1695 constant name is qualified by the locale base name.  An internal
  1696 abbreviation takes care for convenient input and output, making the
  1697 parameters implicit and using the original short name.  See also
  1698 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1699 entities from a monomorphic theory.
  1700 
  1701 Presently, abbreviations are only available 'in' a target locale, but
  1702 not inherited by general import expressions.  Also note that
  1703 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1704 'translations' in common applications.  The "no_abbrevs" print mode
  1705 prevents folding of abbreviations in term output.
  1706 
  1707 Concrete syntax is attached to specified constants in internal form,
  1708 independently of name spaces.  The parse tree representation is
  1709 slightly different -- use 'notation' instead of raw 'syntax', and
  1710 'translations' with explicit "CONST" markup to accommodate this.
  1711 
  1712 * Pure/Isar: unified syntax for new-style specification mechanisms
  1713 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1714 full type inference and dummy patterns ("_").  For example:
  1715 
  1716   definition "K x _ = x"
  1717 
  1718   inductive conj for A B
  1719   where "A ==> B ==> conj A B"
  1720 
  1721 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1722 the current context.  Print mode "no_abbrevs" prevents inversion of
  1723 abbreviations on output.
  1724 
  1725 * Isar/locales: improved parameter handling: use of locales "var" and
  1726 "struct" no longer necessary; - parameter renamings are no longer
  1727 required to be injective.  For example, this allows to define
  1728 endomorphisms as locale endom = homom mult mult h.
  1729 
  1730 * Isar/locales: changed the way locales with predicates are defined.
  1731 Instead of accumulating the specification, the imported expression is
  1732 now an interpretation.  INCOMPATIBILITY: different normal form of
  1733 locale expressions.  In particular, in interpretations of locales with
  1734 predicates, goals repesenting already interpreted fragments are not
  1735 removed automatically.  Use methods `intro_locales' and
  1736 `unfold_locales'; see below.
  1737 
  1738 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1739 provide backward reasoning on locales predicates.  The methods are
  1740 aware of interpretations and discharge corresponding goals.
  1741 `intro_locales' is less aggressive then `unfold_locales' and does not
  1742 unfold predicates to assumptions.
  1743 
  1744 * Isar/locales: the order in which locale fragments are accumulated
  1745 has changed.  This enables to override declarations from fragments due
  1746 to interpretations -- for example, unwanted simp rules.
  1747 
  1748 * Isar/locales: interpretation in theories and proof contexts has been
  1749 extended.  One may now specify (and prove) equations, which are
  1750 unfolded in interpreted theorems.  This is useful for replacing
  1751 defined concepts (constants depending on locale parameters) by
  1752 concepts already existing in the target context.  Example:
  1753 
  1754   interpretation partial_order ["op <= :: [int, int] => bool"]
  1755     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1756 
  1757 Typically, the constant `partial_order.less' is created by a
  1758 definition specification element in the context of locale
  1759 partial_order.
  1760 
  1761 * Method "induct": improved internal context management to support
  1762 local fixes and defines on-the-fly. Thus explicit meta-level
  1763 connectives !!  and ==> are rarely required anymore in inductive goals
  1764 (using object-logic connectives for this purpose has been long
  1765 obsolete anyway). Common proof patterns are explained in
  1766 src/HOL/Induct/Common_Patterns.thy, see also
  1767 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1768 examples.
  1769 
  1770 * Method "induct": improved handling of simultaneous goals. Instead of
  1771 introducing object-level conjunction, the statement is now split into
  1772 several conclusions, while the corresponding symbolic cases are nested
  1773 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1774 see src/HOL/Induct/Common_Patterns.thy, for example.
  1775 
  1776 * Method "induct": mutual induction rules are now specified as a list
  1777 of rule sharing the same induction cases. HOL packages usually provide
  1778 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1779 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1780 mutual induction rules differently, i.e. like this:
  1781 
  1782   (induct rule: foo_bar.inducts)
  1783   (induct set: foo bar)
  1784   (induct pred: foo bar)
  1785   (induct type: foo bar)
  1786 
  1787 The ML function ProjectRule.projections turns old-style rules into the
  1788 new format.
  1789 
  1790 * Method "coinduct": dual of induction, see
  1791 src/HOL/Library/Coinductive_List.thy for various examples.
  1792 
  1793 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1794 considered a legacy feature.
  1795 
  1796 * Attribute "symmetric" produces result with standardized schematic
  1797 variables (index 0).  Potential INCOMPATIBILITY.
  1798 
  1799 * Simplifier: by default the simplifier trace only shows top level
  1800 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1801 default. Thus there is less danger of being flooded by the trace. The
  1802 trace indicates where parts have been suppressed.
  1803   
  1804 * Provers/classical: removed obsolete classical version of elim_format
  1805 attribute; classical elim/dest rules are now treated uniformly when
  1806 manipulating the claset.
  1807 
  1808 * Provers/classical: stricter checks to ensure that supplied intro,
  1809 dest and elim rules are well-formed; dest and elim rules must have at
  1810 least one premise.
  1811 
  1812 * Provers/classical: attributes dest/elim/intro take an optional
  1813 weight argument for the rule (just as the Pure versions).  Weights are
  1814 ignored by automated tools, but determine the search order of single
  1815 rule steps.
  1816 
  1817 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1818 where the body does not mention the bound variable.  Note that dummy
  1819 patterns implicitly depend on their context of bounds, which makes
  1820 "{_. _}" match any set comprehension as expected.  Potential
  1821 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1822 constant "_idtdummy" in the binding position.
  1823 
  1824 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1825 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1826 for example "A -> B" => "Pi A (%_. B)".
  1827 
  1828 * Pure: 'class_deps' command visualizes the subclass relation, using
  1829 the graph browser tool.
  1830 
  1831 * Pure: 'print_theory' now suppresses certain internal declarations by
  1832 default; use '!' option for full details.
  1833 
  1834 
  1835 *** HOL ***
  1836 
  1837 * Method "metis" proves goals by applying the Metis general-purpose
  1838 resolution prover (see also http://gilith.com/software/metis/).
  1839 Examples are in the directory MetisExamples.  WARNING: the
  1840 Isabelle/HOL-Metis integration does not yet work properly with
  1841 multi-threading.
  1842   
  1843 * Command 'sledgehammer' invokes external automatic theorem provers as
  1844 background processes.  It generates calls to the "metis" method if
  1845 successful. These can be pasted into the proof.  Users do not have to
  1846 wait for the automatic provers to return.  WARNING: does not really
  1847 work with multi-threading.
  1848 
  1849 * New "auto_quickcheck" feature tests outermost goal statements for
  1850 potential counter-examples.  Controlled by ML references
  1851 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1852 5000 milliseconds).  Fails silently if statements is outside of
  1853 executable fragment, or any other codgenerator problem occurs.
  1854 
  1855 * New constant "undefined" with axiom "undefined x = undefined".
  1856 
  1857 * Added class "HOL.eq", allowing for code generation with polymorphic
  1858 equality.
  1859 
  1860 * Some renaming of class constants due to canonical name prefixing in
  1861 the new 'class' package:
  1862 
  1863     HOL.abs ~> HOL.abs_class.abs
  1864     HOL.divide ~> HOL.divide_class.divide
  1865     0 ~> HOL.zero_class.zero
  1866     1 ~> HOL.one_class.one
  1867     op + ~> HOL.plus_class.plus
  1868     op - ~> HOL.minus_class.minus
  1869     uminus ~> HOL.minus_class.uminus
  1870     op * ~> HOL.times_class.times
  1871     op < ~> HOL.ord_class.less
  1872     op <= > HOL.ord_class.less_eq
  1873     Nat.power ~> Power.power_class.power
  1874     Nat.size ~> Nat.size_class.size
  1875     Numeral.number_of ~> Numeral.number_class.number_of
  1876     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1877     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1878     Orderings.min ~> Orderings.ord_class.min
  1879     Orderings.max ~> Orderings.ord_class.max
  1880     Divides.op div ~> Divides.div_class.div
  1881     Divides.op mod ~> Divides.div_class.mod
  1882     Divides.op dvd ~> Divides.div_class.dvd
  1883 
  1884 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1885 
  1886 a) User-defined constants using any of the names "plus", "minus",
  1887 "times", "less" or "less_eq". The standard syntax translations for
  1888 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1889 names.
  1890 
  1891 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1892 INCOMPATIBILITY: use more specific names.
  1893 
  1894 c) Permutative equations (e.g. "a + b = b + a")
  1895 Since the change of names also changes the order of terms, permutative
  1896 rewrite rules may get applied in a different order. Experience shows
  1897 that this is rarely the case (only two adaptions in the whole Isabelle
  1898 distribution).  INCOMPATIBILITY: rewrite proofs
  1899 
  1900 d) ML code directly refering to constant names
  1901 This in general only affects hand-written proof tactics, simprocs and
  1902 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1903 Consider using @{const_name} antiquotation.
  1904 
  1905 * New class "default" with associated constant "default".
  1906 
  1907 * Function "sgn" is now overloaded and available on int, real, complex
  1908 (and other numeric types), using class "sgn".  Two possible defs of
  1909 sgn are given as equational assumptions in the classes sgn_if and
  1910 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1911 INCOMPATIBILITY.
  1912 
  1913 * Locale "partial_order" now unified with class "order" (cf. theory
  1914 Orderings), added parameter "less".  INCOMPATIBILITY.
  1915 
  1916 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1917 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1918 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1919 
  1920 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1921 changed order of proof goals in instance proofs.
  1922 
  1923 * The transitivity reasoner for partial and linear orders is set up
  1924 for classes "order" and "linorder".  Instances of the reasoner are available
  1925 in all contexts importing or interpreting the corresponding locales.
  1926 Method "order" invokes the reasoner separately; the reasoner
  1927 is also integrated with the Simplifier as a solver.  Diagnostic
  1928 command 'print_orders' shows the available instances of the reasoner
  1929 in the current context.
  1930 
  1931 * Localized monotonicity predicate in theory "Orderings"; integrated
  1932 lemmas max_of_mono and min_of_mono with this predicate.
  1933 INCOMPATIBILITY.
  1934 
  1935 * Formulation of theorem "dense" changed slightly due to integration
  1936 with new class dense_linear_order.
  1937 
  1938 * Uniform lattice theory development in HOL.
  1939 
  1940     constants "meet" and "join" now named "inf" and "sup"
  1941     constant "Meet" now named "Inf"
  1942 
  1943     classes "meet_semilorder" and "join_semilorder" now named
  1944       "lower_semilattice" and "upper_semilattice"
  1945     class "lorder" now named "lattice"
  1946     class "comp_lat" now named "complete_lattice"
  1947 
  1948     Instantiation of lattice classes allows explicit definitions
  1949     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1950 
  1951   INCOMPATIBILITY.  Theorem renames:
  1952 
  1953     meet_left_le            ~> inf_le1
  1954     meet_right_le           ~> inf_le2
  1955     join_left_le            ~> sup_ge1
  1956     join_right_le           ~> sup_ge2
  1957     meet_join_le            ~> inf_sup_ord
  1958     le_meetI                ~> le_infI
  1959     join_leI                ~> le_supI
  1960     le_meet                 ~> le_inf_iff
  1961     le_join                 ~> ge_sup_conv
  1962     meet_idempotent         ~> inf_idem
  1963     join_idempotent         ~> sup_idem
  1964     meet_comm               ~> inf_commute
  1965     join_comm               ~> sup_commute
  1966     meet_leI1               ~> le_infI1
  1967     meet_leI2               ~> le_infI2
  1968     le_joinI1               ~> le_supI1
  1969     le_joinI2               ~> le_supI2
  1970     meet_assoc              ~> inf_assoc
  1971     join_assoc              ~> sup_assoc
  1972     meet_left_comm          ~> inf_left_commute
  1973     meet_left_idempotent    ~> inf_left_idem
  1974     join_left_comm          ~> sup_left_commute
  1975     join_left_idempotent    ~> sup_left_idem
  1976     meet_aci                ~> inf_aci
  1977     join_aci                ~> sup_aci
  1978     le_def_meet             ~> le_iff_inf
  1979     le_def_join             ~> le_iff_sup
  1980     join_absorp2            ~> sup_absorb2
  1981     join_absorp1            ~> sup_absorb1
  1982     meet_absorp1            ~> inf_absorb1
  1983     meet_absorp2            ~> inf_absorb2
  1984     meet_join_absorp        ~> inf_sup_absorb
  1985     join_meet_absorp        ~> sup_inf_absorb
  1986     distrib_join_le         ~> distrib_sup_le
  1987     distrib_meet_le         ~> distrib_inf_le
  1988 
  1989     add_meet_distrib_left   ~> add_inf_distrib_left
  1990     add_join_distrib_left   ~> add_sup_distrib_left
  1991     is_join_neg_meet        ~> is_join_neg_inf
  1992     is_meet_neg_join        ~> is_meet_neg_sup
  1993     add_meet_distrib_right  ~> add_inf_distrib_right
  1994     add_join_distrib_right  ~> add_sup_distrib_right
  1995     add_meet_join_distribs  ~> add_sup_inf_distribs
  1996     join_eq_neg_meet        ~> sup_eq_neg_inf
  1997     meet_eq_neg_join        ~> inf_eq_neg_sup
  1998     add_eq_meet_join        ~> add_eq_inf_sup
  1999     meet_0_imp_0            ~> inf_0_imp_0
  2000     join_0_imp_0            ~> sup_0_imp_0
  2001     meet_0_eq_0             ~> inf_0_eq_0
  2002     join_0_eq_0             ~> sup_0_eq_0
  2003     neg_meet_eq_join        ~> neg_inf_eq_sup
  2004     neg_join_eq_meet        ~> neg_sup_eq_inf
  2005     join_eq_if              ~> sup_eq_if
  2006 
  2007     mono_meet               ~> mono_inf
  2008     mono_join               ~> mono_sup
  2009     meet_bool_eq            ~> inf_bool_eq
  2010     join_bool_eq            ~> sup_bool_eq
  2011     meet_fun_eq             ~> inf_fun_eq
  2012     join_fun_eq             ~> sup_fun_eq
  2013     meet_set_eq             ~> inf_set_eq
  2014     join_set_eq             ~> sup_set_eq
  2015     meet1_iff               ~> inf1_iff
  2016     meet2_iff               ~> inf2_iff
  2017     meet1I                  ~> inf1I
  2018     meet2I                  ~> inf2I
  2019     meet1D1                 ~> inf1D1
  2020     meet2D1                 ~> inf2D1
  2021     meet1D2                 ~> inf1D2
  2022     meet2D2                 ~> inf2D2
  2023     meet1E                  ~> inf1E
  2024     meet2E                  ~> inf2E
  2025     join1_iff               ~> sup1_iff
  2026     join2_iff               ~> sup2_iff
  2027     join1I1                 ~> sup1I1
  2028     join2I1                 ~> sup2I1
  2029     join1I1                 ~> sup1I1
  2030     join2I2                 ~> sup1I2
  2031     join1CI                 ~> sup1CI
  2032     join2CI                 ~> sup2CI
  2033     join1E                  ~> sup1E
  2034     join2E                  ~> sup2E
  2035 
  2036     is_meet_Meet            ~> is_meet_Inf
  2037     Meet_bool_def           ~> Inf_bool_def
  2038     Meet_fun_def            ~> Inf_fun_def
  2039     Meet_greatest           ~> Inf_greatest
  2040     Meet_lower              ~> Inf_lower
  2041     Meet_set_def            ~> Inf_set_def
  2042 
  2043     Sup_def                 ~> Sup_Inf
  2044     Sup_bool_eq             ~> Sup_bool_def
  2045     Sup_fun_eq              ~> Sup_fun_def
  2046     Sup_set_eq              ~> Sup_set_def
  2047 
  2048     listsp_meetI            ~> listsp_infI
  2049     listsp_meet_eq          ~> listsp_inf_eq
  2050 
  2051     meet_min                ~> inf_min
  2052     join_max                ~> sup_max
  2053 
  2054 * Added syntactic class "size"; overloaded constant "size" now has
  2055 type "'a::size ==> bool"
  2056 
  2057 * Internal reorganisation of `size' of datatypes: size theorems
  2058 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2059 simplification rules by default!); theorems "prod.size" now named
  2060 "*.size".
  2061 
  2062 * Class "div" now inherits from class "times" rather than "type".
  2063 INCOMPATIBILITY.
  2064 
  2065 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2066 Linorder etc.  have disappeared; operations defined in terms of
  2067 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2068 
  2069 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2070 
  2071 * HOL-Word: New extensive library and type for generic, fixed size
  2072 machine words, with arithemtic, bit-wise, shifting and rotating
  2073 operations, reflection into int, nat, and bool lists, automation for
  2074 linear arithmetic (by automatic reflection into nat or int), including
  2075 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2076 arithmetic type classes, supporting automatic simplification of
  2077 numerals on all operations.
  2078 
  2079 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2080 
  2081 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2082 
  2083 * Code generator library theories:
  2084   - Code_Integer represents HOL integers by big integer literals in target
  2085     languages.
  2086   - Code_Char represents HOL characters by character literals in target
  2087     languages.
  2088   - Code_Char_chr like Code_Char, but also offers treatment of character
  2089     codes; includes Code_Integer.
  2090   - Executable_Set allows to generate code for finite sets using lists.
  2091   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2092     denominator).
  2093   - Executable_Real implements a subset of real numbers, namly those
  2094     representable by rational numbers.
  2095   - Efficient_Nat implements natural numbers by integers, which in general will
  2096     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2097     includes Code_Integer.
  2098   - Code_Index provides an additional datatype index which is mapped to
  2099     target-language built-in integers.
  2100   - Code_Message provides an additional datatype message_string which is isomorphic to
  2101     strings; messages are mapped to target-language strings.
  2102 
  2103 * New package for inductive predicates
  2104 
  2105   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2106 
  2107     inductive
  2108       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2109       for z_1 :: U_1 and ... and z_n :: U_m
  2110     where
  2111       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2112     | ...
  2113 
  2114   with full support for type-inference, rather than
  2115 
  2116     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2117 
  2118     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2119     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2120 
  2121     inductive "s z_1 ... z_m"
  2122     intros
  2123       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2124       ...
  2125 
  2126   For backward compatibility, there is a wrapper allowing inductive
  2127   sets to be defined with the new package via
  2128 
  2129     inductive_set
  2130       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2131       for z_1 :: U_1 and ... and z_n :: U_m
  2132     where
  2133       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2134     | ...
  2135 
  2136   or
  2137 
  2138     inductive_set
  2139       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2140       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2141       for z_1 :: U_1 and ... and z_n :: U_m
  2142     where
  2143       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2144     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2145     | ...
  2146 
  2147   if the additional syntax "p ..." is required.
  2148 
  2149   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2150   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2151 
  2152   INCOMPATIBILITIES:
  2153 
  2154   - Since declaration and definition of inductive sets or predicates
  2155     is no longer separated, abbreviations involving the newly
  2156     introduced sets or predicates must be specified together with the
  2157     introduction rules after the 'where' keyword (see above), rather
  2158     than before the actual inductive definition.
  2159 
  2160   - The variables in induction and elimination rules are now
  2161     quantified in the order of their occurrence in the introduction
  2162     rules, rather than in alphabetical order. Since this may break
  2163     some proofs, these proofs either have to be repaired, e.g. by
  2164     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2165     statements of the form
  2166 
  2167       case (rule_i a_i_1 ... a_i_{k_i})
  2168 
  2169     or the old order of quantification has to be restored by explicitly adding
  2170     meta-level quantifiers in the introduction rules, i.e.
  2171 
  2172       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2173 
  2174   - The format of the elimination rules is now
  2175 
  2176       p z_1 ... z_m x_1 ... x_n ==>
  2177         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2178         ==> ... ==> P
  2179 
  2180     for predicates and
  2181 
  2182       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2183         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2184         ==> ... ==> P
  2185 
  2186     for sets rather than
  2187 
  2188       x : s z_1 ... z_m ==>
  2189         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2190         ==> ... ==> P
  2191 
  2192     This may require terms in goals to be expanded to n-tuples
  2193     (e.g. using case_tac or simplification with the split_paired_all
  2194     rule) before the above elimination rule is applicable.
  2195 
  2196   - The elimination or case analysis rules for (mutually) inductive
  2197     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2198     list of rules "p_1_..._p_k.elims" is no longer available.
  2199 
  2200 * New package "function"/"fun" for general recursive functions,
  2201 supporting mutual and nested recursion, definitions in local contexts,
  2202 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2203 for small examples, and the separate tutorial on the function
  2204 package. The old recdef "package" is still available as before, but
  2205 users are encouraged to use the new package.
  2206 
  2207 * Method "lexicographic_order" automatically synthesizes termination
  2208 relations as lexicographic combinations of size measures. 
  2209 
  2210 * Case-expressions allow arbitrary constructor-patterns (including
  2211 "_") and take their order into account, like in functional
  2212 programming.  Internally, this is translated into nested
  2213 case-expressions; missing cases are added and mapped to the predefined
  2214 constant "undefined". In complicated cases printing may no longer show
  2215 the original input but the internal form. Lambda-abstractions allow
  2216 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2217 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2218 variable.
  2219 
  2220 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2221 is an abbreviation for "of_nat :: nat => int". The simplification
  2222 rules for "of_nat" have been changed to work like "int" did
  2223 previously.  Potential INCOMPATIBILITY:
  2224   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2225   - of_nat_diff and of_nat_mult are no longer default simp rules
  2226 
  2227 * Method "algebra" solves polynomial equations over (semi)rings using
  2228 Groebner bases. The (semi)ring structure is defined by locales and the
  2229 tool setup depends on that generic context. Installing the method for
  2230 a specific type involves instantiating the locale and possibly adding
  2231 declarations for computation on the coefficients.  The method is
  2232 already instantiated for natural numbers and for the axiomatic class
  2233 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2234 CALCULEMUS 2007 for the general principles underlying this
  2235 architecture of context-aware proof-tools.
  2236 
  2237 * Method "ferrack" implements quantifier elimination over
  2238 special-purpose dense linear orders using locales (analogous to
  2239 "algebra"). The method is already installed for class
  2240 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2241 rat, etc.
  2242 
  2243 * Former constant "List.op @" now named "List.append".  Use ML
  2244 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2245 circumvent possible incompatibilities when working on ML level.
  2246 
  2247 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2248 
  2249 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2250 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2251 
  2252 * New syntax for Haskell-like list comprehension (input only), eg.
  2253 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2254 
  2255 * The special syntax for function "filter" has changed from [x :
  2256 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2257 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2258 
  2259 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2260 defined on nat only, as an abbreviation for [a..<Suc b]
  2261 INCOMPATIBILITY.
  2262 
  2263 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2264 
  2265 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2266 
  2267 * New lemma collection field_simps (an extension of ring_simps) for
  2268 manipulating (in)equations involving division. Multiplies with all
  2269 denominators that can be proved to be non-zero (in equations) or
  2270 positive/negative (in inequations).
  2271 
  2272 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2273 have been improved and renamed to ring_simps, group_simps and
  2274 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2275 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2276 
  2277 * Theory Library/Commutative_Ring: switched from recdef to function
  2278 package; constants add, mul, pow now curried.  Infix syntax for
  2279 algebraic operations.
  2280 
  2281 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2282 INCOMPATIBILITY.
  2283 
  2284 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2285 INCOMPATIBILITY.
  2286 
  2287 * HOL/records: generalised field-update to take a function on the
  2288 field rather than the new value: r(|A := x|) is translated to A_update
  2289 (K x) r The K-combinator that is internally used is called K_record.
  2290 INCOMPATIBILITY: Usage of the plain update functions has to be
  2291 adapted.
  2292  
  2293 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2294 * x = 0, which are required for a semiring.  Richer structures do not
  2295 inherit from semiring_0 anymore, because this property is a theorem
  2296 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2297 there is more to prove, but this is mostly trivial.
  2298 
  2299 * Class "recpower" is generalized to arbitrary monoids, not just
  2300 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2301 commutativity or semiring properties additionally.
  2302 
  2303 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2304 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2305 better use 'abbreviation'.
  2306 
  2307 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2308 
  2309 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2310 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2311 significant changes for setting up numeral syntax for types:
  2312   - New constants Numeral.pred and Numeral.succ instead
  2313       of former Numeral.bin_pred and Numeral.bin_succ.
  2314   - Use integer operations instead of bin_add, bin_mult and so on.
  2315   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2316   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2317 
  2318 See src/HOL/Integ/IntArith.thy for an example setup.
  2319 
  2320 * Command 'normal_form' computes the normal form of a term that may
  2321 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2322 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2323 heavy-duty computations because the functions are compiled to ML
  2324 first.  Correspondingly, a method "normalization" is provided.  See
  2325 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2326 
  2327 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2328 25 like -->); output depends on the "iff" print_mode, the default is
  2329 "A = B" (with priority 50).
  2330 
  2331 * Relations less (<) and less_eq (<=) are also available on type bool.
  2332 Modified syntax to disallow nesting without explicit parentheses,
  2333 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2334 INCOMPATIBILITY.
  2335 
  2336 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2337 
  2338 * Relation composition operator "op O" now has precedence 75 and binds
  2339 stronger than union and intersection. INCOMPATIBILITY.
  2340 
  2341 * The old set interval syntax "{m..n(}" (and relatives) has been
  2342 removed.  Use "{m..<n}" (and relatives) instead.
  2343 
  2344 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2345 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2346 ``declare [[simproc del: neq]]''.
  2347 
  2348 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2349 True/False.
  2350 
  2351 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2352 
  2353 * Theorem setsum_mult renamed to setsum_right_distrib.
  2354 
  2355 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2356 ``rule'' method.
  2357 
  2358 * Reimplemented methods "sat" and "satx", with several improvements:
  2359 goals no longer need to be stated as "<prems> ==> False", equivalences
  2360 (i.e. "=" on type bool) are handled, variable names of the form
  2361 "lit_<n>" are no longer reserved, significant speedup.
  2362 
  2363 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2364 zChaff is still supported as well.
  2365 
  2366 * 'inductive' and 'datatype': provide projections of mutual rules,
  2367 bundled as foo_bar.inducts;
  2368 
  2369 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2370 Library.
  2371 
  2372 * Library: moved theory Accessible_Part to main HOL.
  2373 
  2374 * Library: added theory Coinductive_List of potentially infinite lists
  2375 as greatest fixed-point.
  2376 
  2377 * Library: added theory AssocList which implements (finite) maps as
  2378 association lists.
  2379 
  2380 * Method "evaluation" solves goals (i.e. a boolean expression)
  2381 efficiently by compiling it to ML.  The goal is "proved" (via an
  2382 oracle) if it evaluates to True.
  2383 
  2384 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2385 also when invoked by the simplifier.  This results in the Simplifier
  2386 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2387 Configuration option fast_arith_split_limit=0 recovers the old
  2388 behavior.
  2389 
  2390 * Support for hex (0x20) and binary (0b1001) numerals.
  2391 
  2392 * New method: reify eqs (t), where eqs are equations for an
  2393 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2394 parameter, computes a term s::'b and a list xs::'a list and proves the
  2395 theorem I xs s = t. This is also known as reification or quoting. The
  2396 resulting theorem is applied to the subgoal to substitute t with I xs
  2397 s.  If t is omitted, the subgoal itself is reified.
  2398 
  2399 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2400 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2401 where f is supposed to be a computable function (in the sense of code
  2402 generattion). The method uses reify to compute s and xs as above then
  2403 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2404 r and finally gets the theorem t = r, which is again applied to the
  2405 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2406 
  2407 * Reflection: Automatic reification now handels binding, an example is
  2408 available in src/HOL/ex/ReflectionEx.thy
  2409 
  2410 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2411 command 'statespace' that is similar to 'record', but introduces an
  2412 abstract specification based on the locale infrastructure instead of
  2413 HOL types.  This leads to extra flexibility in composing state spaces,
  2414 in particular multiple inheritance and renaming of components.
  2415 
  2416 
  2417 *** HOL-Complex ***
  2418 
  2419 * Hyperreal: Functions root and sqrt are now defined on negative real
  2420 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2421 Nonnegativity side conditions have been removed from many lemmas, so
  2422 that more subgoals may now be solved by simplification; potential
  2423 INCOMPATIBILITY.
  2424 
  2425 * Real: new type classes formalize real normed vector spaces and
  2426 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2427 and norm :: 'a => real.
  2428 
  2429 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2430 reals into other types. The overloaded constant Reals :: 'a set is now
  2431 defined as range of_real; potential INCOMPATIBILITY.
  2432 
  2433 * Real: proper support for ML code generation, including 'quickcheck'.
  2434 Reals are implemented as arbitrary precision rationals.
  2435 
  2436 * Hyperreal: Several constants that previously worked only for the
  2437 reals have been generalized, so they now work over arbitrary vector
  2438 spaces. Type annotations may need to be added in some cases; potential
  2439 INCOMPATIBILITY.
  2440 
  2441   Infinitesimal  :: ('a::real_normed_vector) star set
  2442   HFinite        :: ('a::real_normed_vector) star set
  2443   HInfinite      :: ('a::real_normed_vector) star set
  2444   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2445   monad          :: ('a::real_normed_vector) star => 'a star set
  2446   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2447   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2448   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2449   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2450   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2451   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2452   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2453   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2454   sgn            :: 'a::real_normed_vector => 'a
  2455   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2456 
  2457 * Complex: Some complex-specific constants are now abbreviations for
  2458 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2459 hnorm.  Other constants have been entirely removed in favor of the
  2460 polymorphic versions (INCOMPATIBILITY):
  2461 
  2462   approx        <-- capprox
  2463   HFinite       <-- CFinite
  2464   HInfinite     <-- CInfinite
  2465   Infinitesimal <-- CInfinitesimal
  2466   monad         <-- cmonad
  2467   galaxy        <-- cgalaxy
  2468   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2469   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2470   (ns)deriv     <-- (ns)cderiv
  2471 
  2472 
  2473 *** HOL-Algebra ***
  2474 
  2475 * Formalisation of ideals and the quotient construction over rings.
  2476 
  2477 * Order and lattice theory no longer based on records.
  2478 INCOMPATIBILITY.
  2479 
  2480 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2481 greatest_closed.  INCOMPATIBILITY.
  2482 
  2483 * Method algebra is now set up via an attribute.  For examples see
  2484 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2485 of algebraic structures.
  2486 
  2487 * Renamed theory CRing to Ring.
  2488 
  2489 
  2490 *** HOL-Nominal ***
  2491 
  2492 * Substantial, yet incomplete support for nominal datatypes (binding
  2493 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2494 src/HOL/Nominal/Examples.  Prospective users should consult
  2495 http://isabelle.in.tum.de/nominal/
  2496 
  2497 
  2498 *** ML ***
  2499 
  2500 * ML basics: just one true type int, which coincides with IntInf.int
  2501 (even on SML/NJ).
  2502 
  2503 * ML within Isar: antiquotations allow to embed statically-checked
  2504 formal entities in the source, referring to the context available at
  2505 compile-time.  For example:
  2506 
  2507 ML {* @{sort "{zero,one}"} *}
  2508 ML {* @{typ "'a => 'b"} *}
  2509 ML {* @{term "%x. x"} *}
  2510 ML {* @{prop "x == y"} *}
  2511 ML {* @{ctyp "'a => 'b"} *}
  2512 ML {* @{cterm "%x. x"} *}
  2513 ML {* @{cprop "x == y"} *}
  2514 ML {* @{thm asm_rl} *}
  2515 ML {* @{thms asm_rl} *}
  2516 ML {* @{type_name c} *}
  2517 ML {* @{type_syntax c} *}
  2518 ML {* @{const_name c} *}
  2519 ML {* @{const_syntax c} *}
  2520 ML {* @{context} *}
  2521 ML {* @{theory} *}
  2522 ML {* @{theory Pure} *}
  2523 ML {* @{theory_ref} *}
  2524 ML {* @{theory_ref Pure} *}
  2525 ML {* @{simpset} *}
  2526 ML {* @{claset} *}
  2527 ML {* @{clasimpset} *}
  2528 
  2529 The same works for sources being ``used'' within an Isar context.
  2530 
  2531 * ML in Isar: improved error reporting; extra verbosity with
  2532 ML_Context.trace enabled.
  2533 
  2534 * Pure/General/table.ML: the join operations now works via exceptions
  2535 DUP/SAME instead of type option. This is simpler in simple cases, and
  2536 admits slightly more efficient complex applications.
  2537 
  2538 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2539 use Context.generic instead of just theory.
  2540 
  2541 * Pure: datatype Context.generic joins theory/Proof.context and
  2542 provides some facilities for code that works in either kind of
  2543 context, notably GenericDataFun for uniform theory and proof data.
  2544 
  2545 * Pure: simplified internal attribute type, which is now always
  2546 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2547 local (Proof.context) attributes have been discontinued, while
  2548 minimizing code duplication. Thm.rule_attribute and
  2549 Thm.declaration_attribute build canonical attributes; see also structure
  2550 Context for further operations on Context.generic, notably
  2551 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2552 declarations and definitions.
  2553 
  2554 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2555 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2556 init only required for impure data. INCOMPATIBILITY: empty really need
  2557 to be empty (no dependencies on theory content!)
  2558 
  2559 * Pure/kernel: consts certification ignores sort constraints given in
  2560 signature declarations. (This information is not relevant to the
  2561 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2562 potential INCOMPATIBILITY.
  2563 
  2564 * Pure: axiomatic type classes are now purely definitional, with
  2565 explicit proofs of class axioms and super class relations performed
  2566 internally. See Pure/axclass.ML for the main internal interfaces --
  2567 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2568 AxClass.axiomatize_class/classrel/arity supersede
  2569 Sign.add_classes/classrel/arities.
  2570 
  2571 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2572 global/local versions on theory vs. Proof.context have been
  2573 discontinued; Attrib.syntax and Method.syntax have been adapted
  2574 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2575 attributes, methods, etc.
  2576 
  2577 * Pure: several functions of signature "... -> theory -> theory * ..."
  2578 have been reoriented to "... -> theory -> ... * theory" in order to
  2579 allow natural usage in combination with the ||>, ||>>, |-> and
  2580 fold_map combinators.
  2581 
  2582 * Pure: official theorem names (closed derivations) and additional
  2583 comments (tags) are now strictly separate.  Name hints -- which are
  2584 maintained as tags -- may be attached any time without affecting the
  2585 derivation.
  2586 
  2587 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2588 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2589 achieve the old behaviour.
  2590 
  2591 * Pure: the "Goal" constant is now called "prop", supporting a
  2592 slightly more general idea of ``protecting'' meta-level rule
  2593 statements.
  2594 
  2595 * Pure: Logic.(un)varify only works in a global context, which is now
  2596 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2597 Logic.legacy_(un)varify as temporary workaround.
  2598 
  2599 * Pure: structure Name provides scalable operations for generating
  2600 internal variable names, notably Name.variants etc.  This replaces
  2601 some popular functions from term.ML:
  2602 
  2603   Term.variant		->  Name.variant
  2604   Term.variantlist	->  Name.variant_list
  2605   Term.invent_names	->  Name.invent_list
  2606 
  2607 Note that low-level renaming rarely occurs in new code -- operations
  2608 from structure Variable are used instead (see below).
  2609 
  2610 * Pure: structure Variable provides fundamental operations for proper
  2611 treatment of fixed/schematic variables in a context.  For example,
  2612 Variable.import introduces fixes for schematics of given facts and
  2613 Variable.export reverses the effect (up to renaming) -- this replaces
  2614 various freeze_thaw operations.
  2615 
  2616 * Pure: structure Goal provides simple interfaces for
  2617 init/conclude/finish and tactical prove operations (replacing former
  2618 Tactic.prove).  Goal.prove is the canonical way to prove results
  2619 within a given context; Goal.prove_global is a degraded version for
  2620 theory level goals, including a global Drule.standard.  Note that
  2621 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2622 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2623 in a locale context).
  2624 
  2625 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2626 and type checking (Syntax.check_term etc.), with common combinations
  2627 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2628 which are considered legacy and await removal.
  2629 
  2630 * Pure/Syntax: generic interfaces for type unchecking
  2631 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2632 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2633 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2634 available for convenience, but refer to the very same operations using
  2635 a mere theory instead of a full context.
  2636 
  2637 * Isar: simplified treatment of user-level errors, using exception
  2638 ERROR of string uniformly.  Function error now merely raises ERROR,
  2639 without any side effect on output channels.  The Isar toplevel takes
  2640 care of proper display of ERROR exceptions.  ML code may use plain
  2641 handle/can/try; cat_error may be used to concatenate errors like this:
  2642 
  2643   ... handle ERROR msg => cat_error msg "..."
  2644 
  2645 Toplevel ML code (run directly or through the Isar toplevel) may be
  2646 embedded into the Isar toplevel with exception display/debug like
  2647 this:
  2648 
  2649   Isar.toplevel (fn () => ...)
  2650 
  2651 INCOMPATIBILITY, removed special transform_error facilities, removed
  2652 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2653 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2654 -- use plain ERROR instead.
  2655 
  2656 * Isar: theory setup now has type (theory -> theory), instead of a
  2657 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2658 
  2659 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2660 ProofContext.debug/verbose flags.
  2661 
  2662 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2663 theory before entering a proof state.  Transactions now always see a
  2664 quasi-functional intermediate checkpoint, both in interactive and
  2665 batch mode.
  2666 
  2667 * Isar: simplified interfaces for outer syntax.  Renamed
  2668 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2669 OuterSyntax.add_parsers -- this functionality is now included in
  2670 OuterSyntax.command etc.  INCOMPATIBILITY.
  2671 
  2672 * Simplifier: the simpset of a running simplification process now
  2673 contains a proof context (cf. Simplifier.the_context), which is the
  2674 very context that the initial simpset has been retrieved from (by
  2675 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2676 (solver, looper etc.) may depend on arbitrary proof data.
  2677 
  2678 * Simplifier.inherit_context inherits the proof context (plus the
  2679 local bounds) of the current simplification process; any simproc
  2680 etc. that calls the Simplifier recursively should do this!  Removed
  2681 former Simplifier.inherit_bounds, which is already included here --
  2682 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2683 specify an explicit context using Simplifier.context/theory_context.
  2684 
  2685 * Simplifier/Classical Reasoner: more abstract interfaces
  2686 change_simpset/claset for modifying the simpset/claset reference of a
  2687 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2688 INCOMPATIBILITY.
  2689 
  2690 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2691 "Trueprop" etc.
  2692 
  2693 
  2694 *** System ***
  2695 
  2696 * settings: the default heap location within ISABELLE_HOME_USER now
  2697 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2698 Isabelle installations.
  2699 
  2700 * isabelle-process: option -S (secure mode) disables some critical
  2701 operations, notably runtime compilation and evaluation of ML source
  2702 code.
  2703 
  2704 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2705 
  2706 * Support for parallel execution, using native multicore support of
  2707 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2708 independent theories, according to the given theory header
  2709 specifications. The maximum number of worker threads is specified via
  2710 usedir option -M or the "max-threads" setting in Proof General. A
  2711 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2712 to 6 on a 8-core machine.  User-code needs to observe certain
  2713 guidelines for thread-safe programming, see appendix A in the Isar
  2714 Implementation manual.
  2715 
  2716 
  2717 
  2718 New in Isabelle2005 (October 2005)
  2719 ----------------------------------
  2720 
  2721 *** General ***
  2722 
  2723 * Theory headers: the new header syntax for Isar theories is
  2724 
  2725   theory <name>
  2726   imports <theory1> ... <theoryN>
  2727   uses <file1> ... <fileM>
  2728   begin
  2729 
  2730 where the 'uses' part is optional.  The previous syntax
  2731 
  2732   theory <name> = <theory1> + ... + <theoryN>:
  2733 
  2734 will disappear in the next release.  Use isatool fixheaders to convert
  2735 existing theory files.  Note that there is no change in ancient
  2736 non-Isar theories now, but these will disappear soon.
  2737 
  2738 * Theory loader: parent theories can now also be referred to via
  2739 relative and absolute paths.
  2740 
  2741 * Command 'find_theorems' searches for a list of criteria instead of a
  2742 list of constants. Known criteria are: intro, elim, dest, name:string,
  2743 simp:term, and any term. Criteria can be preceded by '-' to select
  2744 theorems that do not match. Intro, elim, dest select theorems that
  2745 match the current goal, name:s selects theorems whose fully qualified
  2746 name contain s, and simp:term selects all simplification rules whose
  2747 lhs match term.  Any other term is interpreted as pattern and selects
  2748 all theorems matching the pattern. Available in ProofGeneral under
  2749 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2750 
  2751   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2752 
  2753 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2754 matching the current goal as introduction rule and not having "HOL."
  2755 in their name (i.e. not being defined in theory HOL).
  2756 
  2757 * Command 'thms_containing' has been discontinued in favour of
  2758 'find_theorems'; INCOMPATIBILITY.
  2759 
  2760 * Communication with Proof General is now 8bit clean, which means that
  2761 Unicode text in UTF-8 encoding may be used within theory texts (both
  2762 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2763 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2764 
  2765   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2766   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2767 
  2768 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2769 Classical Reasoner.  Typical big applications run around 2 times
  2770 faster.
  2771 
  2772 
  2773 *** Document preparation ***
  2774 
  2775 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2776 of raw sources.  Only those symbols that do not require additional
  2777 LaTeX packages (depending on comments in isabellesym.sty) are
  2778 displayed properly, everything else is left verbatim.  isatool display
  2779 and isatool print are used as front ends (these are subject to the
  2780 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2781 
  2782 * Command tags control specific markup of certain regions of text,
  2783 notably folding and hiding.  Predefined tags include "theory" (for
  2784 theory begin and end), "proof" for proof commands, and "ML" for
  2785 commands involving ML code; the additional tags "visible" and
  2786 "invisible" are unused by default.  Users may give explicit tag
  2787 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2788 interpretation of tags is determined by the LaTeX job during document
  2789 preparation: see option -V of isatool usedir, or options -n and -t of
  2790 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2791 \isadroptag.
  2792 
  2793 Several document versions may be produced at the same time via isatool
  2794 usedir (the generated index.html will link all of them).  Typical
  2795 specifications include ''-V document=theory,proof,ML'' to present
  2796 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2797 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2798 these parts without any formal replacement text.  The Isabelle site
  2799 default settings produce ''document'' and ''outline'' versions as
  2800 specified above.
  2801 
  2802 * Several new antiquotations:
  2803 
  2804   @{term_type term} prints a term with its type annotated;
  2805 
  2806   @{typeof term} prints the type of a term;
  2807 
  2808   @{const const} is the same as @{term const}, but checks that the
  2809   argument is a known logical constant;
  2810 
  2811   @{term_style style term} and @{thm_style style thm} print a term or
  2812   theorem applying a "style" to it
  2813 
  2814   @{ML text}
  2815 
  2816 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2817 definitions, equations, inequations etc., 'concl' printing only the
  2818 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2819 to print the specified premise.  TermStyle.add_style provides an ML
  2820 interface for introducing further styles.  See also the "LaTeX Sugar"
  2821 document practical applications.  The ML antiquotation prints
  2822 type-checked ML expressions verbatim.
  2823 
  2824 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2825 and 'text' support optional locale specification '(in loc)', which
  2826 specifies the default context for interpreting antiquotations.  For
  2827 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2828 
  2829 * Option 'locale=NAME' of antiquotations specifies an alternative
  2830 context interpreting the subsequent argument.  For example: @{thm
  2831 [locale=lattice] inf_assoc}.
  2832 
  2833 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2834 a proof context.
  2835 
  2836 * Proper output of antiquotations for theory commands involving a
  2837 proof context (such as 'locale' or 'theorem (in loc) ...').
  2838 
  2839 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2840 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2841 
  2842 * isatool usedir: new option -C (default true) controls whether option
  2843 -D should include a copy of the original document directory; -C false
  2844 prevents unwanted effects such as copying of administrative CVS data.
  2845 
  2846 
  2847 *** Pure ***
  2848 
  2849 * Considerably improved version of 'constdefs' command.  Now performs
  2850 automatic type-inference of declared constants; additional support for
  2851 local structure declarations (cf. locales and HOL records), see also
  2852 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2853 sequential dependencies of definitions within a single 'constdefs'
  2854 section; moreover, the declared name needs to be an identifier.  If
  2855 all fails, consider to fall back on 'consts' and 'defs' separately.
  2856 
  2857 * Improved indexed syntax and implicit structures.  First of all,
  2858 indexed syntax provides a notational device for subscripted
  2859 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2860 expressions.  Secondly, in a local context with structure
  2861 declarations, number indexes \<^sub>n or the empty index (default
  2862 number 1) refer to a certain fixed variable implicitly; option
  2863 show_structs controls printing of implicit structures.  Typical
  2864 applications of these concepts involve record types and locales.
  2865 
  2866 * New command 'no_syntax' removes grammar declarations (and
  2867 translations) resulting from the given syntax specification, which is
  2868 interpreted in the same manner as for the 'syntax' command.
  2869 
  2870 * 'Advanced' translation functions (parse_translation etc.) may depend
  2871 on the signature of the theory context being presently used for
  2872 parsing/printing, see also isar-ref manual.
  2873 
  2874 * Improved 'oracle' command provides a type-safe interface to turn an
  2875 ML expression of type theory -> T -> term into a primitive rule of
  2876 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2877 is already included here); see also FOL/ex/IffExample.thy;
  2878 INCOMPATIBILITY.
  2879 
  2880 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2881 before); "cI" is no longer bound, use "c.intro" instead.
  2882 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2883 axclasses vs. locales.
  2884 
  2885 * Improved internal renaming of symbolic identifiers -- attach primes
  2886 instead of base 26 numbers.
  2887 
  2888 * New flag show_question_marks controls printing of leading question
  2889 marks in schematic variable names.
  2890 
  2891 * In schematic variable names, *any* symbol following \<^isub> or
  2892 \<^isup> is now treated as part of the base name.  For example, the
  2893 following works without printing of awkward ".0" indexes:
  2894 
  2895   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2896     by simp
  2897 
  2898 * Inner syntax includes (*(*nested*) comments*).
  2899 
  2900 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2901 annotations as "(00...)".
  2902 
  2903 * Clear separation of logical types and nonterminals, where the latter
  2904 may only occur in 'syntax' specifications or type abbreviations.
  2905 Before that distinction was only partially implemented via type class
  2906 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2907 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2908 exotic syntax specifications may require further adaption
  2909 (e.g. Cube/Cube.thy).
  2910 
  2911 * Removed obsolete type class "logic", use the top sort {} instead.
  2912 Note that non-logical types should be declared as 'nonterminals'
  2913 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2914 specifications.
  2915 
  2916 * Attributes 'induct' and 'cases': type or set names may now be
  2917 locally fixed variables as well.
  2918 
  2919 * Simplifier: can now control the depth to which conditional rewriting
  2920 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2921 Limit.
  2922 
  2923 * Simplifier: simplification procedures may now take the current
  2924 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2925 interface), which is very useful for calling the Simplifier
  2926 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2927 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2928 low-level mk_simproc no longer applies Logic.varify internally, to
  2929 allow for use in a context of fixed variables.
  2930 
  2931 * thin_tac now works even if the assumption being deleted contains !!
  2932 or ==>.  More generally, erule now works even if the major premise of
  2933 the elimination rule contains !! or ==>.
  2934 
  2935 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2936 
  2937 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2938 from Pure, which contains all common declarations already.  Both
  2939 theories are defined via plain Isabelle/Isar .thy files.
  2940 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2941 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2942 use isatool fixcpure to adapt your theory and ML sources.
  2943 
  2944 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2945 selections of theorems in named facts via index ranges.
  2946 
  2947 * 'print_theorems': in theory mode, really print the difference
  2948 wrt. the last state (works for interactive theory development only),
  2949 in proof mode print all local facts (cf. 'print_facts');
  2950 
  2951 * 'hide': option '(open)' hides only base names.
  2952 
  2953 * More efficient treatment of intermediate checkpoints in interactive
  2954 theory development.
  2955 
  2956 * Code generator is now invoked via code_module (incremental code
  2957 generation) and code_library (modular code generation, ML structures
  2958 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2959 must be quoted when used as identifiers.
  2960 
  2961 * New 'value' command for reading, evaluating and printing terms using
  2962 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2963 quoted when used as identifier.
  2964 
  2965 
  2966 *** Locales ***
  2967 
  2968 * New commands for the interpretation of locale expressions in
  2969 theories (1), locales (2) and proof contexts (3).  These generate
  2970 proof obligations from the expression specification.  After the
  2971 obligations have been discharged, theorems of the expression are added
  2972 to the theory, target locale or proof context.  The synopsis of the
  2973 commands is a follows:
  2974 
  2975   (1) interpretation expr inst
  2976   (2) interpretation target < expr
  2977   (3) interpret expr inst
  2978 
  2979 Interpretation in theories and proof contexts require a parameter
  2980 instantiation of terms from the current context.  This is applied to
  2981 specifications and theorems of the interpreted expression.
  2982 Interpretation in locales only permits parameter renaming through the
  2983 locale expression.  Interpretation is smart in that interpretations
  2984 that are active already do not occur in proof obligations, neither are
  2985 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2986 inspect active interpretations of a particular locale.  For details,
  2987 see the Isar Reference manual.  Examples can be found in
  2988 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2989 
  2990 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2991 'interpret' instead.
  2992 
  2993 * New context element 'constrains' for adding type constraints to
  2994 parameters.
  2995 
  2996 * Context expressions: renaming of parameters with syntax
  2997 redeclaration.
  2998 
  2999 * Locale declaration: 'includes' disallowed.
  3000 
  3001 * Proper static binding of attribute syntax -- i.e. types / terms /
  3002 facts mentioned as arguments are always those of the locale definition
  3003 context, independently of the context of later invocations.  Moreover,
  3004 locale operations (renaming and type / term instantiation) are applied
  3005 to attribute arguments as expected.
  3006 
  3007 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3008 actual attributes; rare situations may require Attrib.attribute to
  3009 embed those attributes into Attrib.src that lack concrete syntax.
  3010 Attribute implementations need to cooperate properly with the static
  3011 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3012 Attrib.XXX_thm etc. already do the right thing without further
  3013 intervention.  Only unusual applications -- such as "where" or "of"
  3014 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3015 on the context and the facts involved -- may have to assign parsed
  3016 values to argument tokens explicitly.
  3017 
  3018 * Changed parameter management in theorem generation for long goal
  3019 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3020 theorem statement in rare situations.
  3021 
  3022 * Locale inspection command 'print_locale' omits notes elements.  Use
  3023 'print_locale!' to have them included in the output.
  3024 
  3025 
  3026 *** Provers ***
  3027 
  3028 * Provers/hypsubst.ML: improved version of the subst method, for
  3029 single-step rewriting: it now works in bound variable contexts. New is
  3030 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3031 rewrite a different subterm than the original subst method, which is
  3032 still available as 'simplesubst'.
  3033 
  3034 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3035 and quasi orders.
  3036 
  3037 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3038 reflexive-transitive closure of relations.
  3039 
  3040 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3041 limit (previously hard-coded with a value of 20) user-definable.
  3042 
  3043 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3044 is peformed already.  Object-logics merely need to finish their
  3045 initial simpset configuration as before.  INCOMPATIBILITY.
  3046 
  3047 
  3048 *** HOL ***
  3049 
  3050 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3051 
  3052   syntax (epsilon)
  3053     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3054 
  3055 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3056 and x-symbol; use option '-m epsilon' to get it actually printed.
  3057 Moreover, the mathematically important symbolic identifier \<epsilon>
  3058 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3059 
  3060 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3061 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3062 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3063 support corresponding Isar calculations.
  3064 
  3065 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3066 instead of ":".
  3067 
  3068 * theory SetInterval: changed the syntax for open intervals:
  3069 
  3070   Old       New
  3071   {..n(}    {..<n}
  3072   {)n..}    {n<..}
  3073   {m..n(}   {m..<n}
  3074   {)m..n}   {m<..n}
  3075   {)m..n(}  {m<..<n}
  3076 
  3077 The old syntax is still supported but will disappear in the next
  3078 release.  For conversion use the following Emacs search and replace
  3079 patterns (these are not perfect but work quite well):
  3080 
  3081   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3082   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3083 
  3084 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3085 equalities in commutative rings; method 'algebra' provides a generic
  3086 interface.
  3087 
  3088 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3089 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3090 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3091 be a tuple pattern.
  3092 
  3093 Some new syntax forms are available:
  3094 
  3095   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3096   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3097   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3098   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3099 
  3100 The latter form "\<Sum>x < k. e" used to be based on a separate
  3101 function "Summation", which has been discontinued.
  3102 
  3103 * theory Finite_Set: in structured induction proofs, the insert case
  3104 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3105 (insert F x)'.
  3106 
  3107 * The 'refute' command has been extended to support a much larger
  3108 fragment of HOL, including axiomatic type classes, constdefs and
  3109 typedefs, inductive datatypes and recursion.
  3110 
  3111 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3112 Requires zChaff with proof generation to be installed.  See
  3113 HOL/ex/SAT_Examples.thy for examples.
  3114 
  3115 * Datatype induction via method 'induct' now preserves the name of the
  3116 induction variable. For example, when proving P(xs::'a list) by
  3117 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3118 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3119 in unstructured proof scripts.
  3120 
  3121 * Reworked implementation of records.  Improved scalability for
  3122 records with many fields, avoiding performance problems for type
  3123 inference. Records are no longer composed of nested field types, but
  3124 of nested extension types. Therefore the record type only grows linear
  3125 in the number of extensions and not in the number of fields.  The
  3126 top-level (users) view on records is preserved.  Potential
  3127 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3128 old record representation. The type generated for a record is called
  3129 <record_name>_ext_type.
  3130 
  3131 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3132 proofs triggered by a record definition or a simproc (if
  3133 quick_and_dirty is enabled).  Definitions of large records can take
  3134 quite long.
  3135 
  3136 New simproc record_upd_simproc for simplification of multiple record
  3137 updates enabled by default.  Moreover, trivial updates are also
  3138 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3139 occasionally, since simplification is more powerful by default.
  3140 
  3141 * typedef: proper support for polymorphic sets, which contain extra
  3142 type-variables in the term.
  3143 
  3144 * Simplifier: automatically reasons about transitivity chains
  3145 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3146 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3147 old proofs break occasionally as simplification may now solve more
  3148 goals than previously.
  3149 
  3150 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3151 present.  Works for all partial orders (class "order"), in particular
  3152 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3153 just like y <= x.
  3154 
  3155 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3156 bound variable or a constant then the let is unfolded.  Otherwise
  3157 first a is simplified to b, and then f b is simplified to g. If
  3158 possible we abstract b from g arriving at "let x = b in h x",
  3159 otherwise we unfold the let and arrive at g.  The simproc can be
  3160 enabled/disabled by the reference use_let_simproc.  Potential
  3161 INCOMPATIBILITY since simplification is more powerful by default.
  3162 
  3163 * Classical reasoning: the meson method now accepts theorems as arguments.
  3164 
  3165 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3166 jobs to provide advice on the provability of subgoals.
  3167 
  3168 * Theory OrderedGroup and Ring_and_Field: various additions and
  3169 improvements to faciliate calculations involving equalities and
  3170 inequalities.
  3171 
  3172 The following theorems have been eliminated or modified
  3173 (INCOMPATIBILITY):
  3174 
  3175   abs_eq             now named abs_of_nonneg
  3176   abs_of_ge_0        now named abs_of_nonneg
  3177   abs_minus_eq       now named abs_of_nonpos
  3178   imp_abs_id         now named abs_of_nonneg
  3179   imp_abs_neg_id     now named abs_of_nonpos
  3180   mult_pos           now named mult_pos_pos
  3181   mult_pos_le        now named mult_nonneg_nonneg
  3182   mult_pos_neg_le    now named mult_nonneg_nonpos
  3183   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3184   mult_neg           now named mult_neg_neg
  3185   mult_neg_le        now named mult_nonpos_nonpos
  3186 
  3187 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3188      
  3189      zero_le_square
  3190      not_square_less_zero 
  3191 
  3192   The following lemmas have been deleted from Real/RealPow:
  3193   
  3194      realpow_zero_zero
  3195      realpow_two
  3196      realpow_less
  3197      zero_le_power
  3198      realpow_two_le
  3199      abs_realpow_two
  3200      realpow_two_abs     
  3201 
  3202 * Theory Parity: added rules for simplifying exponents.
  3203 
  3204 * Theory List:
  3205 
  3206 The following theorems have been eliminated or modified
  3207 (INCOMPATIBILITY):
  3208 
  3209   list_all_Nil       now named list_all.simps(1)
  3210   list_all_Cons      now named list_all.simps(2)
  3211   list_all_conv      now named list_all_iff
  3212   set_mem_eq         now named mem_iff
  3213 
  3214 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3215 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3216 
  3217 
  3218 *** HOL-Complex ***
  3219 
  3220 * Theory RealDef: better support for embedding natural numbers and
  3221 integers in the reals.
  3222 
  3223 The following theorems have been eliminated or modified
  3224 (INCOMPATIBILITY):
  3225 
  3226   exp_ge_add_one_self  now requires no hypotheses
  3227   real_of_int_add      reversed direction of equality (use [symmetric])
  3228   real_of_int_minus    reversed direction of equality (use [symmetric])
  3229   real_of_int_diff     reversed direction of equality (use [symmetric])
  3230   real_of_int_mult     reversed direction of equality (use [symmetric])
  3231 
  3232 * Theory RComplete: expanded support for floor and ceiling functions.
  3233 
  3234 * Theory Ln is new, with properties of the natural logarithm
  3235 
  3236 * Hyperreal: There is a new type constructor "star" for making
  3237 nonstandard types.  The old type names are now type synonyms:
  3238 
  3239   hypreal = real star
  3240   hypnat = nat star
  3241   hcomplex = complex star
  3242 
  3243 * Hyperreal: Many groups of similarly-defined constants have been
  3244 replaced by polymorphic versions (INCOMPATIBILITY):
  3245 
  3246   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3247 
  3248   starset      <-- starsetNat, starsetC
  3249   *s*          <-- *sNat*, *sc*
  3250   starset_n    <-- starsetNat_n, starsetC_n
  3251   *sn*         <-- *sNatn*, *scn*
  3252   InternalSets <-- InternalNatSets, InternalCSets
  3253 
  3254   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3255   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3256   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3257   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3258   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3259 
  3260 * Hyperreal: Many type-specific theorems have been removed in favor of
  3261 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3262 
  3263   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3264   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3265   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3266   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3267   right_minus <-- hypreal_add_minus
  3268   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3269   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3270   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3271   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3272   mult_1_right <-- hcomplex_mult_one_right
  3273   mult_zero_left <-- hcomplex_mult_zero_left
  3274   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3275   right_distrib <-- hypnat_add_mult_distrib2
  3276   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3277   right_inverse <-- hypreal_mult_inverse
  3278   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3279   order_refl <-- {hypreal,hypnat}_le_refl
  3280   order_trans <-- {hypreal,hypnat}_le_trans
  3281   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3282   order_less_le <-- {hypreal,hypnat}_less_le
  3283   linorder_linear <-- {hypreal,hypnat}_le_linear
  3284   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3285   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3286   add_nonneg_nonneg <-- hypreal_le_add_order
  3287 
  3288 * Hyperreal: Separate theorems having to do with type-specific
  3289 versions of constants have been merged into theorems that apply to the
  3290 new polymorphic constants (INCOMPATIBILITY):
  3291 
  3292   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3293   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3294   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3295   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3296   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3297   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3298   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3299   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3300   STAR_diff <-- {STAR,STARC}_diff
  3301   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3302     STARC_hcomplex_of_complex}_image_subset
  3303   starset_n_Un <-- starset{Nat,C}_n_Un
  3304   starset_n_Int <-- starset{Nat,C}_n_Int
  3305   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3306   starset_n_diff <-- starset{Nat,C}_n_diff
  3307   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3308   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3309   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3310   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3311   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3312   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3313   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3314   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3315   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3316   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3317   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3318   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3319   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3320   starfun_diff <-- starfun{C,RC,CR}_diff
  3321   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3322   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3323   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3324   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3325   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3326   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3327   starfun_Id <-- starfunC_Id
  3328   starfun_approx <-- starfun{Nat,CR}_approx
  3329   starfun_capprox <-- starfun{C,RC}_capprox
  3330   starfun_abs <-- starfunNat_rabs
  3331   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3332   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3333   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3334   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3335   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3336   starfun_add_approx <-- starfunCR_add_approx
  3337   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3338   starfun_divide <-- starfun{C,CR,RC}_divide
  3339   starfun_n <-- starfun{Nat,C}_n
  3340   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3341   starfun_n_add <-- starfun{Nat,C}_n_add
  3342   starfun_n_add_minus <-- starfunNat_n_add_minus
  3343   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3344   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3345   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3346 
  3347   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3348   star_n_minus <-- {hypreal,hcomplex}_minus
  3349   star_n_diff <-- {hypreal,hcomplex}_diff
  3350   star_n_mult <-- {hypreal,hcomplex}_mult
  3351   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3352   star_n_le <-- {hypreal,hypnat}_le
  3353   star_n_less <-- {hypreal,hypnat}_less
  3354   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3355   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3356   star_n_abs <-- hypreal_hrabs
  3357   star_n_divide <-- hcomplex_divide
  3358 
  3359   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3360   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3361   star_of_diff <-- hypreal_of_real_diff
  3362   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3363   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3364   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3365   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3366   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3367   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3368   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3369   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3370   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3371   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3372   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3373   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3374   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3375   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3376   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3377   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3378   star_of_power <-- hypreal_of_real_power
  3379   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3380 
  3381 * Hyperreal: new method "transfer" that implements the transfer
  3382 principle of nonstandard analysis. With a subgoal that mentions
  3383 nonstandard types like "'a star", the command "apply transfer"
  3384 replaces it with an equivalent one that mentions only standard types.
  3385 To be successful, all free variables must have standard types; non-
  3386 standard variables must have explicit universal quantifiers.
  3387 
  3388 * Hyperreal: A theory of Taylor series.
  3389 
  3390 
  3391 *** HOLCF ***
  3392 
  3393 * Discontinued special version of 'constdefs' (which used to support
  3394 continuous functions) in favor of the general Pure one with full
  3395 type-inference.
  3396 
  3397 * New simplification procedure for solving continuity conditions; it
  3398 is much faster on terms with many nested lambda abstractions (cubic
  3399 instead of exponential time).
  3400 
  3401 * New syntax for domain package: selector names are now optional.
  3402 Parentheses should be omitted unless argument is lazy, for example:
  3403 
  3404   domain 'a stream = cons "'a" (lazy "'a stream")
  3405 
  3406 * New command 'fixrec' for defining recursive functions with pattern
  3407 matching; defining multiple functions with mutual recursion is also
  3408 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3409 sinr, or any data constructor defined by the domain package. The given
  3410 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3411 syntax and examples.
  3412 
  3413 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3414 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3415 but the proof obligation additionally includes an admissibility
  3416 requirement. The packages generate instances of class cpo or pcpo,
  3417 with continuity and strictness theorems for Rep and Abs.
  3418 
  3419 * HOLCF: Many theorems have been renamed according to a more standard naming
  3420 scheme (INCOMPATIBILITY):
  3421 
  3422   foo_inject:  "foo$x = foo$y ==> x = y"
  3423   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3424   foo_less:    "(foo$x << foo$y) = (x << y)"
  3425   foo_strict:  "foo$UU = UU"
  3426   foo_defined: "... ==> foo$x ~= UU"
  3427   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3428 
  3429 
  3430 *** ZF ***
  3431 
  3432 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3433 including the First Isomorphism Theorem (on quotienting by the kernel
  3434 of a homomorphism).
  3435 
  3436 * ZF/Simplifier: install second copy of type solver that actually
  3437 makes use of TC rules declared to Isar proof contexts (or locales);
  3438 the old version is still required for ML proof scripts.
  3439 
  3440 
  3441 *** Cube ***
  3442 
  3443 * Converted to Isar theory format; use locales instead of axiomatic
  3444 theories.
  3445 
  3446 
  3447 *** ML ***
  3448 
  3449 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3450 for ||>, ||>>, |>>,
  3451 
  3452 * Pure/library.ML no longer defines its own option datatype, but uses
  3453 that of the SML basis, which has constructors NONE and SOME instead of
  3454 None and Some, as well as exception Option.Option instead of OPTION.
  3455 The functions the, if_none, is_some, is_none have been adapted
  3456 accordingly, while Option.map replaces apsome.
  3457 
  3458 * Pure/library.ML: the exception LIST has been given up in favour of
  3459 the standard exceptions Empty and Subscript, as well as
  3460 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3461 superceded by the standard hd and tl functions etc.
  3462 
  3463 A number of basic list functions are no longer exported to the ML
  3464 toplevel, as they are variants of predefined functions.  The following
  3465 suggests how one can translate existing code:
  3466 
  3467     rev_append xs ys = List.revAppend (xs, ys)
  3468     nth_elem (i, xs) = List.nth (xs, i)
  3469     last_elem xs = List.last xs
  3470     flat xss = List.concat xss
  3471     seq fs = List.app fs
  3472     partition P xs = List.partition P xs
  3473     mapfilter f xs = List.mapPartial f xs
  3474 
  3475 * Pure/library.ML: several combinators for linear functional
  3476 transformations, notably reverse application and composition:
  3477 
  3478   x |> f                f #> g
  3479   (x, y) |-> f          f #-> g
  3480 
  3481 * Pure/library.ML: introduced/changed precedence of infix operators:
  3482 
  3483   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3484   infix 2 ?;
  3485   infix 3 o oo ooo oooo;
  3486   infix 4 ~~ upto downto;
  3487 
  3488 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3489 infix operators.
  3490 
  3491 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3492 fold_map support linear functional transformations and nesting.  For
  3493 example:
  3494 
  3495   fold f [x1, ..., xN] y =
  3496     y |> f x1 |> ... |> f xN
  3497 
  3498   (fold o fold) f [xs1, ..., xsN] y =
  3499     y |> fold f xs1 |> ... |> fold f xsN
  3500 
  3501   fold f [x1, ..., xN] =
  3502     f x1 #> ... #> f xN
  3503 
  3504   (fold o fold) f [xs1, ..., xsN] =
  3505     fold f xs1 #> ... #> fold f xsN
  3506 
  3507 * Pure/library.ML: the following selectors on type 'a option are
  3508 available:
  3509 
  3510   the:               'a option -> 'a  (*partial*)
  3511   these:             'a option -> 'a  where 'a = 'b list
  3512   the_default: 'a -> 'a option -> 'a
  3513   the_list:          'a option -> 'a list
  3514 
  3515 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3516 basic operations for association lists, following natural argument
  3517 order; moreover the explicit equality predicate passed here avoids
  3518 potentially expensive polymorphic runtime equality checks.
  3519 The old functions may be expressed as follows:
  3520 
  3521   assoc = uncurry (AList.lookup (op =))
  3522   assocs = these oo AList.lookup (op =)
  3523   overwrite = uncurry (AList.update (op =)) o swap
  3524 
  3525 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3526 
  3527   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3528   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3529 
  3530 replacing make_keylist and keyfilter (occassionally used)
  3531 Naive rewrites:
  3532 
  3533   make_keylist = AList.make
  3534   keyfilter = AList.find (op =)
  3535 
  3536 * eq_fst and eq_snd now take explicit equality parameter, thus
  3537   avoiding eqtypes. Naive rewrites:
  3538 
  3539     eq_fst = eq_fst (op =)
  3540     eq_snd = eq_snd (op =)
  3541 
  3542 * Removed deprecated apl and apr (rarely used).
  3543   Naive rewrites:
  3544 
  3545     apl (n, op) =>>= curry op n
  3546     apr (op, m) =>>= fn n => op (n, m)
  3547 
  3548 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3549 provides a reasonably efficient light-weight implementation of sets as
  3550 lists.
  3551 
  3552 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3553 few new operations; existing lookup and update are now curried to
  3554 follow natural argument order (for use with fold etc.);
  3555 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3556 
  3557 * Pure/General: output via the Isabelle channels of
  3558 writeln/warning/error etc. is now passed through Output.output, with a
  3559 hook for arbitrary transformations depending on the print_mode
  3560 (cf. Output.add_mode -- the first active mode that provides a output
  3561 function wins).  Already formatted output may be embedded into further
  3562 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3563 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3564 accommodate easy composition of diagnostic messages etc.  Programmers
  3565 rarely need to care about Output.output or Output.raw at all, with
  3566 some notable exceptions: Output.output is required when bypassing the
  3567 standard channels (writeln etc.), or in token translations to produce
  3568 properly formatted results; Output.raw is required when capturing
  3569 already output material that will eventually be presented to the user
  3570 a second time.  For the default print mode, both Output.output and
  3571 Output.raw have no effect.
  3572 
  3573 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3574 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3575 cumulative results are displayed at the end of a batch session.
  3576 
  3577 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3578 replaced by File.platform_path and File.shell_path (with appropriate
  3579 hooks).  This provides a clean interface for unusual systems where the
  3580 internal and external process view of file names are different.
  3581 
  3582 * Pure: more efficient orders for basic syntactic entities: added
  3583 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3584 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3585 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3586 orders now -- potential INCOMPATIBILITY for code that depends on a
  3587 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3588 Library.sort_strings on result).
  3589 
  3590 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3591 fold_types traverse types/terms from left to right, observing natural
  3592 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3593 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3594 
  3595 * Pure: name spaces have been refined, with significant changes of the
  3596 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3597 to extern(_table).  The plain name entry path is superceded by a
  3598 general 'naming' context, which also includes the 'policy' to produce
  3599 a fully qualified name and external accesses of a fully qualified
  3600 name; NameSpace.extend is superceded by context dependent
  3601 Sign.declare_name.  Several theory and proof context operations modify
  3602 the naming context.  Especially note Theory.restore_naming and
  3603 ProofContext.restore_naming to get back to a sane state; note that
  3604 Theory.add_path is no longer sufficient to recover from
  3605 Theory.absolute_path in particular.
  3606 
  3607 * Pure: new flags short_names (default false) and unique_names
  3608 (default true) for controlling output of qualified names.  If
  3609 short_names is set, names are printed unqualified.  If unique_names is
  3610 reset, the name prefix is reduced to the minimum required to achieve
  3611 the original result when interning again, even if there is an overlap
  3612 with earlier declarations.
  3613 
  3614 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3615 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3616 (useful for printing error messages).  INCOMPATIBILITY.
  3617 
  3618 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3619 Theory.theory are now identified, referring to the universal
  3620 Context.theory (see Pure/context.ML).  Actual signature and theory
  3621 content is managed as theory data.  The old code and interfaces were
  3622 spread over many files and structures; the new arrangement introduces
  3623 considerable INCOMPATIBILITY to gain more clarity:
  3624 
  3625   Context -- theory management operations (name, identity, inclusion,
  3626     parents, ancestors, merge, etc.), plus generic theory data;
  3627 
  3628   Sign -- logical signature and syntax operations (declaring consts,
  3629     types, etc.), plus certify/read for common entities;
  3630 
  3631   Theory -- logical theory operations (stating axioms, definitions,
  3632     oracles), plus a copy of logical signature operations (consts,
  3633     types, etc.); also a few basic management operations (Theory.copy,
  3634     Theory.merge, etc.)
  3635 
  3636 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3637 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3638 for convenience -- they merely return the theory.
  3639 
  3640 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3641 
  3642 * Pure: the Isar proof context type is already defined early in Pure
  3643 as Context.proof (note that ProofContext.context and Proof.context are
  3644 aliases, where the latter is the preferred name).  This enables other
  3645 Isabelle components to refer to that type even before Isar is present.
  3646 
  3647 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3648 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3649 any of these kinds.  For example, Sign.intern typeK is now
  3650 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3651 Theory.hide_types.  Also note that former
  3652 Theory.hide_classes/types/consts are now
  3653 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3654 internalize their arguments!  INCOMPATIBILITY.
  3655 
  3656 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3657 datatype thmref (with constructors Name and NameSelection) instead of
  3658 plain string -- INCOMPATIBILITY;
  3659 
  3660 * Pure: cases produced by proof methods specify options, where NONE
  3661 means to remove case bindings -- INCOMPATIBILITY in
  3662 (RAW_)METHOD_CASES.
  3663 
  3664 * Pure: the following operations retrieve axioms or theorems from a
  3665 theory node or theory hierarchy, respectively:
  3666 
  3667   Theory.axioms_of: theory -> (string * term) list
  3668   Theory.all_axioms_of: theory -> (string * term) list
  3669   PureThy.thms_of: theory -> (string * thm) list
  3670   PureThy.all_thms_of: theory -> (string * thm) list
  3671 
  3672 * Pure: print_tac now outputs the goal through the trace channel.
  3673 
  3674 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3675 Reference Toplevel.debug (default false) controls detailed printing
  3676 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3677 controls execution profiling -- set to 1 for time and 2 for space
  3678 (both increase the runtime).
  3679 
  3680 * Isar session: The initial use of ROOT.ML is now always timed,
  3681 i.e. the log will show the actual process times, in contrast to the
  3682 elapsed wall-clock time that the outer shell wrapper produces.
  3683 
  3684 * Simplifier: improved handling of bound variables (nameless
  3685 representation, avoid allocating new strings).  Simprocs that invoke
  3686 the Simplifier recursively should use Simplifier.inherit_bounds to
  3687 avoid local name clashes.  Failure to do so produces warnings
  3688 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3689 for further details.
  3690 
  3691 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3692 bindings for all theorems stored within a given theory; this may help
  3693 in porting non-Isar theories to Isar ones, while keeping ML proof
  3694 scripts for the time being.
  3695 
  3696 * ML operator HTML.with_charset specifies the charset begin used for
  3697 generated HTML files.  For example:
  3698 
  3699   HTML.with_charset "utf-8" use_thy "Hebrew";
  3700   HTML.with_charset "utf-8" use_thy "Chinese";
  3701 
  3702 
  3703 *** System ***
  3704 
  3705 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3706 isabelle, isatool etc.).
  3707 
  3708 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3709 isatool doc, isatool mkdir, display_drafts etc.).
  3710 
  3711 * isatool usedir: option -f allows specification of the ML file to be
  3712 used by Isabelle; default is ROOT.ML.
  3713 
  3714 * New isatool version outputs the version identifier of the Isabelle
  3715 distribution being used.
  3716 
  3717 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3718 (containing Boolean satisfiability problems) into Isabelle/HOL
  3719 theories.
  3720 
  3721 
  3722 
  3723 New in Isabelle2004 (April 2004)
  3724 --------------------------------
  3725 
  3726 *** General ***
  3727 
  3728 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3729   Replaces linorder.ML.
  3730 
  3731 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3732   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3733   (\<a>...\<z>), are now considered normal letters, and can therefore
  3734   be used anywhere where an ASCII letter (a...zA...Z) has until
  3735   now. COMPATIBILITY: This obviously changes the parsing of some
  3736   terms, especially where a symbol has been used as a binder, say
  3737   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3738   as an identifier.  Fix it by inserting a space around former
  3739   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3740   existing theory and ML files.
  3741 
  3742 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3743 
  3744 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3745   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3746   a normal (but invisible) letter. For multiple letter subscripts repeat
  3747   \<^isub> like this: x\<^isub>1\<^isub>2.
  3748 
  3749 * Pure: There are now sub-/superscripts that can span more than one
  3750   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3751   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3752   superscript. The new control characters are not identifier parts.
  3753 
  3754 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3755   content of "..." to the latex file instead of \isacntrl... . The "..."
  3756   may consist of any printable characters excluding the end bracket >.
  3757 
  3758 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3759   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3760   declare constants "final", which prevents their being given a definition
  3761   later.  It is useful for constants whose behaviour is fixed axiomatically
  3762   rather than definitionally, such as the meta-logic connectives.
  3763 
  3764 * Pure: 'instance' now handles general arities with general sorts
  3765   (i.e. intersections of classes),
  3766 
  3767 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3768   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3769   It can be changed to alter the colors/layout of generated pages.
  3770 
  3771 
  3772 *** Isar ***
  3773 
  3774 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3775   cut_tac, subgoal_tac and thin_tac:
  3776   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3777     locales are no longer forced to write Isar proof scripts.
  3778     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3779     emulations.
  3780   - INCOMPATIBILITY: names of variables to be instantiated may no
  3781     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3782     This is consistent with the instantiation attribute "where".
  3783 
  3784 * Attributes "where" and "of":
  3785   - Now take type variables of instantiated theorem into account when reading
  3786     the instantiation string.  This fixes a bug that caused instantiated
  3787     theorems to have too special types in some circumstances.
  3788   - "where" permits explicit instantiations of type variables.
  3789 
  3790 * Calculation commands "moreover" and "also" no longer interfere with
  3791   current facts ("this"), admitting arbitrary combinations with "then"
  3792   and derived forms.
  3793 
  3794 * Locales:
  3795   - Goal statements involving the context element "includes" no longer
  3796     generate theorems with internal delta predicates (those ending on
  3797     "_axioms") in the premise.
  3798     Resolve particular premise with <locale>.intro to obtain old form.
  3799   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3800     specification and "includes" elements in goal statement.
  3801   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3802     [intro?] and [elim?] (respectively) by default.
  3803   - Experimental command for instantiation of locales in proof contexts:
  3804         instantiate <label>[<attrs>]: <loc>
  3805     Instantiates locale <loc> and adds all its theorems to the current context
  3806     taking into account their attributes.  Label and attrs are optional
  3807     modifiers, like in theorem declarations.  If present, names of
  3808     instantiated theorems are qualified with <label>, and the attributes
  3809     <attrs> are applied after any attributes these theorems might have already.
  3810       If the locale has assumptions, a chained fact of the form
  3811     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3812     are derived.  The command does not support old-style locales declared
  3813     with "locale (open)".
  3814       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3815 
  3816 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3817   (Isar) contexts.
  3818 
  3819 
  3820 *** HOL ***
  3821 
  3822 * Proof import: new image HOL4 contains the imported library from
  3823   the HOL4 system with about 2500 theorems. It is imported by
  3824   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3825   can be used like any other Isabelle image.  See
  3826   HOL/Import/HOL/README for more information.
  3827 
  3828 * Simplifier:
  3829   - Much improved handling of linear and partial orders.
  3830     Reasoners for linear and partial orders are set up for type classes
  3831     "linorder" and "order" respectively, and are added to the default simpset
  3832     as solvers.  This means that the simplifier can build transitivity chains
  3833     to solve goals from the assumptions.
  3834   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3835     of blast or auto after simplification become unnecessary because the goal
  3836     is solved by simplification already.
  3837 
  3838 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3839     all proved in axiomatic type classes for semirings, rings and fields.
  3840 
  3841 * Numerics:
  3842   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3843     now formalized using the Ring_and_Field theory mentioned above.
  3844   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3845     than before, because now they are set up once in a generic manner.
  3846   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3847     Look for the general versions in Ring_and_Field (and Power if they concern
  3848     exponentiation).
  3849 
  3850 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3851 
  3852 * Records:
  3853   - Record types are now by default printed with their type abbreviation
  3854     instead of the list of all field types. This can be configured via
  3855     the reference "print_record_type_abbr".
  3856   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3857     (not enabled by default).
  3858   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3859     EX x. x = sel r to True (not enabled by default).
  3860   - Tactic "record_split_simp_tac" to split and simplify records added.
  3861 
  3862 * 'specification' command added, allowing for definition by
  3863   specification.  There is also an 'ax_specification' command that
  3864   introduces the new constants axiomatically.
  3865 
  3866 * arith(_tac) is now able to generate counterexamples for reals as well.
  3867 
  3868 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3869 
  3870 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3871   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3872 
  3873 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3874   matrix theory to linear programming.
  3875 
  3876 * Unions and Intersections:
  3877   The latex output syntax of UN and INT has been changed
  3878   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3879   i.e. the index formulae has become a subscript.
  3880   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3881 
  3882 * Unions and Intersections over Intervals:
  3883   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3884   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3885   like in normal math, and corresponding versions for < and for intersection.
  3886 
  3887 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3888   lexicographic dictonary ordering has been added as "lexord".
  3889 
  3890 * ML: the legacy theory structures Int and List have been removed. They had
  3891   conflicted with ML Basis Library structures having the same names.
  3892 
  3893 * 'refute' command added to search for (finite) countermodels.  Only works
  3894   for a fragment of HOL.  The installation of an external SAT solver is
  3895   highly recommended.  See "HOL/Refute.thy" for details.
  3896 
  3897 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3898   formulae under an assignment of free variables to random values.
  3899   In contrast to 'refute', it can deal with inductive datatypes,
  3900   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3901   for examples.
  3902 
  3903 
  3904 *** HOLCF ***
  3905 
  3906 * Streams now come with concatenation and are part of the HOLCF image
  3907 
  3908 
  3909 
  3910 New in Isabelle2003 (May 2003)
  3911 ------------------------------
  3912 
  3913 *** General ***
  3914 
  3915 * Provers/simplifier:
  3916 
  3917   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3918     Assumptions are now subject to complete mutual simplification,
  3919     not just from left to right. The simplifier now preserves
  3920     the order of assumptions.
  3921 
  3922     Potential INCOMPATIBILITY:
  3923 
  3924     -- simp sometimes diverges where the old version did
  3925        not, e.g. invoking simp on the goal
  3926 
  3927         [| P (f x); y = x; f x = f y |] ==> Q
  3928 
  3929        now gives rise to the infinite reduction sequence
  3930 
  3931         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3932 
  3933        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3934        kind of problem.
  3935 
  3936     -- Tactics combining classical reasoner and simplification (such as auto)
  3937        are also affected by this change, because many of them rely on
  3938        simp. They may sometimes diverge as well or yield a different numbers
  3939        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3940        in case of problems. Sometimes subsequent calls to the classical
  3941        reasoner will fail because a preceeding call to the simplifier too
  3942        eagerly simplified the goal, e.g. deleted redundant premises.
  3943 
  3944   - The simplifier trace now shows the names of the applied rewrite rules
  3945 
  3946   - You can limit the number of recursive invocations of the simplifier
  3947     during conditional rewriting (where the simplifie tries to solve the
  3948     conditions before applying the rewrite rule):
  3949     ML "simp_depth_limit := n"
  3950     where n is an integer. Thus you can force termination where previously
  3951     the simplifier would diverge.
  3952 
  3953   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3954 
  3955   - No longer aborts on failed congruence proof.  Instead, the
  3956     congruence is ignored.
  3957 
  3958 * Pure: New generic framework for extracting programs from constructive
  3959   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3960   as HOL/Extraction for some case studies.
  3961 
  3962 * Pure: The main goal of the proof state is no longer shown by default, only
  3963 the subgoals. This behaviour is controlled by a new flag.
  3964    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3965 (ML: Proof.show_main_goal).
  3966 
  3967 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3968 rules whose conclusion matches subgoal 1:
  3969       PG menu: Isabelle/Isar -> Show me -> matching rules
  3970 The rules are ordered by how closely they match the subgoal.
  3971 In particular, rules that solve a subgoal outright are displayed first
  3972 (or rather last, the way they are printed).
  3973 (ML: ProofGeneral.print_intros())
  3974 
  3975 * Pure: New flag trace_unify_fail causes unification to print
  3976 diagnostic information (PG: in trace buffer) when it fails. This is
  3977 useful for figuring out why single step proofs like rule, erule or
  3978 assumption failed.
  3979 
  3980 * Pure: Locale specifications now produce predicate definitions
  3981 according to the body of text (covering assumptions modulo local
  3982 definitions); predicate "loc_axioms" covers newly introduced text,
  3983 while "loc" is cumulative wrt. all included locale expressions; the
  3984 latter view is presented only on export into the global theory
  3985 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3986 on the old view without predicates;
  3987 
  3988 * Pure: predefined locales "var" and "struct" are useful for sharing
  3989 parameters (as in CASL, for example); just specify something like
  3990 ``var x + var y + struct M'' as import;
  3991 
  3992 * Pure: improved thms_containing: proper indexing of facts instead of
  3993 raw theorems; check validity of results wrt. current name space;
  3994 include local facts of proof configuration (also covers active
  3995 locales), cover fixed variables in index; may use "_" in term
  3996 specification; an optional limit for the number of printed facts may
  3997 be given (the default is 40);
  3998 
  3999 * Pure: disallow duplicate fact bindings within new-style theory files
  4000 (batch-mode only);
  4001 
  4002 * Provers: improved induct method: assumptions introduced by case
  4003 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4004 the goal statement); "foo" still refers to all facts collectively;
  4005 
  4006 * Provers: the function blast.overloaded has been removed: all constants
  4007 are regarded as potentially overloaded, which improves robustness in exchange
  4008 for slight decrease in efficiency;
  4009 
  4010 * Provers/linorder: New generic prover for transitivity reasoning over
  4011 linear orders.  Note: this prover is not efficient!
  4012 
  4013 * Isar: preview of problems to finish 'show' now produce an error
  4014 rather than just a warning (in interactive mode);
  4015 
  4016 
  4017 *** HOL ***
  4018 
  4019 * arith(_tac)
  4020 
  4021  - Produces a counter example if it cannot prove a goal.
  4022    Note that the counter example may be spurious if the goal is not a formula
  4023    of quantifier-free linear arithmetic.
  4024    In ProofGeneral the counter example appears in the trace buffer.
  4025 
  4026  - Knows about div k and mod k where k is a numeral of type nat or int.
  4027 
  4028  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4029    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4030    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4031 
  4032 * simp's arithmetic capabilities have been enhanced a bit: it now
  4033 takes ~= in premises into account (by performing a case split);
  4034 
  4035 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4036 are distributed over a sum of terms;
  4037 
  4038 * New tactic "trans_tac" and method "trans" instantiate
  4039 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4040 "<=", "<" and "=").
  4041 
  4042 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4043 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4044 
  4045 * 'typedef' command has new option "open" to suppress the set
  4046 definition;
  4047 
  4048 * functions Min and Max on finite sets have been introduced (theory
  4049 Finite_Set);
  4050 
  4051 * attribute [symmetric] now works for relations as well; it turns
  4052 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4053 
  4054 * induct over a !!-quantified statement (say !!x1..xn):
  4055   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4056 
  4057 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4058 %x. None. Warning: empty_def now refers to the previously hidden definition
  4059 of the empty set.
  4060 
  4061 * Algebra: formalization of classical algebra.  Intended as base for
  4062 any algebraic development in Isabelle.  Currently covers group theory
  4063 (up to Sylow's theorem) and ring theory (Universal Property of
  4064 Univariate Polynomials).  Contributions welcome;
  4065 
  4066 * GroupTheory: deleted, since its material has been moved to Algebra;
  4067 
  4068 * Complex: new directory of the complex numbers with numeric constants,
  4069 nonstandard complex numbers, and some complex analysis, standard and
  4070 nonstandard (Jacques Fleuriot);
  4071 
  4072 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4073 
  4074 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4075 Fleuriot);
  4076 
  4077 * Real/HahnBanach: updated and adapted to locales;
  4078 
  4079 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4080 Gray and Kramer);
  4081 
  4082 * UNITY: added the Meier-Sanders theory of progress sets;
  4083 
  4084 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4085 as abstract algorithms, instantiated to the JVM;
  4086 
  4087 * Bali: Java source language formalization. Type system, operational
  4088 semantics, axiomatic semantics. Supported language features:
  4089 classes, interfaces, objects,virtual methods, static methods,
  4090 static/instance fields, arrays, access modifiers, definite
  4091 assignment, exceptions.
  4092 
  4093 
  4094 *** ZF ***
  4095 
  4096 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4097 universe, etc.);
  4098 
  4099 * Main ZF: virtually all theories converted to new-style format;
  4100 
  4101 
  4102 *** ML ***
  4103 
  4104 * Pure: Tactic.prove provides sane interface for internal proofs;
  4105 omits the infamous "standard" operation, so this is more appropriate
  4106 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4107 
  4108 * Pure: improved error reporting of simprocs;
  4109 
  4110 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4111 up simprocs;
  4112 
  4113 
  4114 *** Document preparation ***
  4115 
  4116 * uses \par instead of \\ for line breaks in theory text. This may
  4117 shift some page breaks in large documents. To get the old behaviour
  4118 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4119 
  4120 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4121 other packages
  4122 
  4123 * \<euro> now needs package babel/greek instead of marvosym (which
  4124 broke \Rightarrow)
  4125 
  4126 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4127 textcomp package)
  4128 
  4129 
  4130 
  4131 New in Isabelle2002 (March 2002)
  4132 --------------------------------
  4133 
  4134 *** Document preparation ***
  4135 
  4136 * greatly simplified document preparation setup, including more
  4137 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4138 instructive isatool mkdir; users should basically be able to get
  4139 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4140 users may run a separate document processing stage manually like this:
  4141 "isatool usedir -D output HOL Test && isatool document Test/output";
  4142 
  4143 * theory dependency graph may now be incorporated into documents;
  4144 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4145 with \includegraphics of LaTeX;
  4146 
  4147 * proper spacing of consecutive markup elements, especially text
  4148 blocks after section headings;
  4149 
  4150 * support bold style (for single symbols only), input syntax is like
  4151 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4152 
  4153 * \<bullet> is now output as bold \cdot by default, which looks much
  4154 better in printed text;
  4155 
  4156 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4157 note that these symbols are currently unavailable in Proof General /
  4158 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4159 
  4160 * isatool latex no longer depends on changed TEXINPUTS, instead
  4161 isatool document copies the Isabelle style files to the target
  4162 location;
  4163 
  4164 
  4165 *** Isar ***
  4166 
  4167 * Pure/Provers: improved proof by cases and induction;
  4168   - 'case' command admits impromptu naming of parameters (such as
  4169     "case (Suc n)");
  4170   - 'induct' method divinates rule instantiation from the inductive
  4171     claim; no longer requires excessive ?P bindings for proper
  4172     instantiation of cases;
  4173   - 'induct' method properly enumerates all possibilities of set/type
  4174     rules; as a consequence facts may be also passed through *type*
  4175     rules without further ado;
  4176   - 'induct' method now derives symbolic cases from the *rulified*
  4177     rule (before it used to rulify cases stemming from the internal
  4178     atomized version); this means that the context of a non-atomic
  4179     statement becomes is included in the hypothesis, avoiding the
  4180     slightly cumbersome show "PROP ?case" form;
  4181   - 'induct' may now use elim-style induction rules without chaining
  4182     facts, using ``missing'' premises from the goal state; this allows
  4183     rules stemming from inductive sets to be applied in unstructured
  4184     scripts, while still benefitting from proper handling of non-atomic
  4185     statements; NB: major inductive premises need to be put first, all
  4186     the rest of the goal is passed through the induction;
  4187   - 'induct' proper support for mutual induction involving non-atomic
  4188     rule statements (uses the new concept of simultaneous goals, see
  4189     below);
  4190   - append all possible rule selections, but only use the first
  4191     success (no backtracking);
  4192   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4193   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4194   - added 'print_induct_rules' (covered by help item in recent Proof
  4195     General versions);
  4196   - moved induct/cases attributes to Pure, methods to Provers;
  4197   - generic method setup instantiated for FOL and HOL;
  4198 
  4199 * Pure: support multiple simultaneous goal statements, for example
  4200 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4201 meta-level mechanism, this acts as if several individual goals had
  4202 been stated separately; in particular common proof methods need to be
  4203 repeated in order to cover all claims; note that a single elimination
  4204 step is *not* sufficient to establish the two conjunctions, so this
  4205 fails:
  4206 
  4207   assume "A & B" then have A and B ..   (*".." fails*)
  4208 
  4209 better use "obtain" in situations as above; alternative refer to
  4210 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4211 
  4212 * Pure: proper integration with ``locales''; unlike the original
  4213 version by Florian Kammller, Isar locales package high-level proof
  4214 contexts rather than raw logical ones (e.g. we admit to include
  4215 attributes everywhere); operations on locales include merge and
  4216 rename; support for implicit arguments (``structures''); simultaneous
  4217 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4218 some examples;
  4219 
  4220 * Pure: the following commands have been ``localized'', supporting a
  4221 target locale specification "(in name)": 'lemma', 'theorem',
  4222 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4223 stored both within the locale and at the theory level (exported and
  4224 qualified by the locale name);
  4225 
  4226 * Pure: theory goals may now be specified in ``long'' form, with
  4227 ad-hoc contexts consisting of arbitrary locale elements. for example
  4228 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4229 definitions may be given, too); the result is a meta-level rule with
  4230 the context elements being discharged in the obvious way;
  4231 
  4232 * Pure: new proof command 'using' allows to augment currently used
  4233 facts after a goal statement ('using' is syntactically analogous to
  4234 'apply', but acts on the goal's facts only); this allows chained facts
  4235 to be separated into parts given before and after a claim, as in
  4236 ``from a and b have C using d and e <proof>'';
  4237 
  4238 * Pure: renamed "antecedent" case to "rule_context";
  4239 
  4240 * Pure: new 'judgment' command records explicit information about the
  4241 object-logic embedding (used by several tools internally); no longer
  4242 use hard-wired "Trueprop";
  4243 
  4244 * Pure: added 'corollary' command;
  4245 
  4246 * Pure: fixed 'token_translation' command;
  4247 
  4248 * Pure: removed obsolete 'exported' attribute;
  4249 
  4250 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4251 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4252 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4253 
  4254 * Pure: method 'atomize' presents local goal premises as object-level
  4255 statements (atomic meta-level propositions); setup controlled via
  4256 rewrite rules declarations of 'atomize' attribute; example
  4257 application: 'induct' method with proper rule statements in improper
  4258 proof *scripts*;
  4259 
  4260 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4261 now consider the syntactic context of assumptions, giving a better
  4262 chance to get type-inference of the arguments right (this is
  4263 especially important for locales);
  4264 
  4265 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4266 mode;
  4267 
  4268 * Pure/obtain: the formal conclusion "thesis", being marked as
  4269 ``internal'', may no longer be reference directly in the text;
  4270 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4271 situations;
  4272 
  4273 * Pure: generic 'sym' attribute which declares a rule both as pure
  4274 'elim?' and for the 'symmetric' operation;
  4275 
  4276 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4277 text; the fixed correlation with particular command syntax has been
  4278 discontinued;
  4279 
  4280 * Pure: new method 'rules' is particularly well-suited for proof
  4281 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4282 but often produces more compact proof terms with less detours;
  4283 
  4284 * Pure/Provers/classical: simplified integration with pure rule
  4285 attributes and methods; the classical "intro?/elim?/dest?"
  4286 declarations coincide with the pure ones; the "rule" method no longer
  4287 includes classically swapped intros; "intro" and "elim" methods no
  4288 longer pick rules from the context; also got rid of ML declarations
  4289 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4290 INCOMPATIBILITY;
  4291 
  4292 * Provers/classical: attribute 'swapped' produces classical inversions
  4293 of introduction rules;
  4294 
  4295 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4296 rules instead of full simplifier context; 'iff' attribute handles
  4297 conditional rules;
  4298 
  4299 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4300 
  4301 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4302 "(permissive)" option to recover old behavior;
  4303 
  4304 * HOL: 'inductive' no longer features separate (collective) attributes
  4305 for 'intros' (was found too confusing);
  4306 
  4307 * HOL: properly declared induction rules less_induct and
  4308 wf_induct_rule;
  4309 
  4310 
  4311 *** HOL ***
  4312 
  4313 * HOL: moved over to sane numeral syntax; the new policy is as
  4314 follows:
  4315 
  4316   - 0 and 1 are polymorphic constants, which are defined on any
  4317   numeric type (nat, int, real etc.);
  4318 
  4319   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4320   binary representation internally;
  4321 
  4322   - type nat has special constructor Suc, and generally prefers Suc 0
  4323   over 1::nat and Suc (Suc 0) over 2::nat;
  4324 
  4325 This change may cause significant problems of INCOMPATIBILITY; here
  4326 are some hints on converting existing sources:
  4327 
  4328   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4329   entities, so expressions involving "-" (unary or binary minus) need
  4330   to be spaced properly;
  4331 
  4332   - existing occurrences of "1" may need to be constraint "1::nat" or
  4333   even replaced by Suc 0; similar for old "2";
  4334 
  4335   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4336 
  4337   - remove all special provisions on numerals in proofs;
  4338 
  4339 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4340 representation (depends on bin_arith_simps in the default context);
  4341 
  4342 * HOL: symbolic syntax for x^2 (numeral 2);
  4343 
  4344 * HOL: the class of all HOL types is now called "type" rather than
  4345 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4346 in axclass/classes, instance/arities, and (usually rare) occurrences
  4347 in typings (of consts etc.); internally the class is called
  4348 "HOL.type", ML programs should refer to HOLogic.typeS;
  4349 
  4350 * HOL/record package improvements:
  4351   - new derived operations "fields" to build a partial record section,
  4352     "extend" to promote a fixed record to a record scheme, and
  4353     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4354     declared as simp by default;
  4355   - shared operations ("more", "fields", etc.) now need to be always
  4356     qualified) --- potential INCOMPATIBILITY;
  4357   - removed "make_scheme" operations (use "make" with "extend") --
  4358     INCOMPATIBILITY;
  4359   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4360   - provides cases/induct rules for use with corresponding Isar
  4361     methods (for concrete records, record schemes, concrete more
  4362     parts, and schematic more parts -- in that order);
  4363   - internal definitions directly based on a light-weight abstract
  4364     theory of product types over typedef rather than datatype;
  4365 
  4366 * HOL: generic code generator for generating executable ML code from
  4367 specifications; specific support for HOL constructs such as inductive
  4368 datatypes and sets, as well as recursive functions; can be invoked
  4369 via 'generate_code' theory section;
  4370 
  4371 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4372 
  4373 * HOL: consolidated and renamed several theories.  In particular:
  4374         Ord.thy has been absorbed into HOL.thy
  4375         String.thy has been absorbed into List.thy
  4376 
  4377 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4378 (beware of argument permutation!);
  4379 
  4380 * HOL: linorder_less_split superseded by linorder_cases;
  4381 
  4382 * HOL/List: "nodups" renamed to "distinct";
  4383 
  4384 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4385 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4386   - Ex_def has changed, now need to use some_eq_ex
  4387 
  4388 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4389 in this (rare) case use:
  4390 
  4391   delSWrapper "split_all_tac"
  4392   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4393 
  4394 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4395 MAY FAIL;
  4396 
  4397 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4398 Isabelle's type classes, ^ on functions and relations has too general
  4399 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4400 necessary to attach explicit type constraints;
  4401 
  4402 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4403 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4404 renamed accordingly (eg "compI" -> "rel_compI").
  4405 
  4406 * HOL: syntax translations now work properly with numerals and records
  4407 expressions;
  4408 
  4409 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4410 of "lam" -- INCOMPATIBILITY;
  4411 
  4412 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4413 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4414 renamed "Product_Type.unit";
  4415 
  4416 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4417 
  4418 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4419 the "cases" method);
  4420 
  4421 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4422 Florian Kammller);
  4423 
  4424 * HOL/IMP: updated and converted to new-style theory format; several
  4425 parts turned into readable document, with proper Isar proof texts and
  4426 some explanations (by Gerwin Klein);
  4427 
  4428 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4429 
  4430 * HOL-Hyperreal is now a logic image;
  4431 
  4432 
  4433 *** HOLCF ***
  4434 
  4435 * Isar: consts/constdefs supports mixfix syntax for continuous
  4436 operations;
  4437 
  4438 * Isar: domain package adapted to new-style theory format, e.g. see
  4439 HOLCF/ex/Dnat.thy;
  4440 
  4441 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4442 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4443 lift.induct_tac, always use UU instead of Undef;
  4444 
  4445 * HOLCF/IMP: updated and converted to new-style theory;
  4446 
  4447 
  4448 *** ZF ***
  4449 
  4450 * Isar: proper integration of logic-specific tools and packages,
  4451 including theory commands '(co)inductive', '(co)datatype',
  4452 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4453 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4454 
  4455 * theory Main no longer includes AC; for the Axiom of Choice, base
  4456 your theory on Main_ZFC;
  4457 
  4458 * the integer library now covers quotients and remainders, with many
  4459 laws relating division to addition, multiplication, etc.;
  4460 
  4461 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4462 typeless version of the formalism;
  4463 
  4464 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4465 format;
  4466 
  4467 * ZF/Induct: new directory for examples of inductive definitions,
  4468 including theory Multiset for multiset orderings; converted to
  4469 new-style theory format;
  4470 
  4471 * ZF: many new theorems about lists, ordinals, etc.;
  4472 
  4473 
  4474 *** General ***
  4475 
  4476 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4477 variable proof controls level of detail: 0 = no proofs (only oracle
  4478 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4479 also ref manual for further ML interfaces;
  4480 
  4481 * Pure/axclass: removed obsolete ML interface
  4482 goal_subclass/goal_arity;
  4483 
  4484 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4485 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4486 separate tokens, so expressions involving minus need to be spaced
  4487 properly;
  4488 
  4489 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4490 rather than "infixl" or "infixr";
  4491 
  4492 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4493 sort constraint specifications in type inference; e.g. "x::_::foo"
  4494 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4495 type variable);
  4496 
  4497 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4498 control output of nested => (types); the default behavior is
  4499 "type_brackets";
  4500 
  4501 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4502 tokens into AST constants;
  4503 
  4504 * Pure/syntax: prefer later declarations of translations and print
  4505 translation functions; potential INCOMPATIBILITY: need to reverse
  4506 multiple declarations for same syntax element constant;
  4507 
  4508 * Pure/show_hyps reset by default (in accordance to existing Isar
  4509 practice);
  4510 
  4511 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4512 addSafter;
  4513 
  4514 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4515 as well;
  4516 
  4517 * system: tested support for MacOS X; should be able to get Isabelle +
  4518 Proof General to work in a plain Terminal after installing Poly/ML
  4519 (e.g. from the Isabelle distribution area) and GNU bash alone
  4520 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4521 support requires further installations, e.g. from
  4522 http://fink.sourceforge.net/);
  4523 
  4524 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4525 
  4526 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4527 of 40 MB), cf. ML_OPTIONS;
  4528 
  4529 * system: Proof General keywords specification is now part of the
  4530 Isabelle distribution (see etc/isar-keywords.el);
  4531 
  4532 * system: support for persistent Proof General sessions (refrain from
  4533 outdating all loaded theories on startup); user may create writable
  4534 logic images like this: ``isabelle -q HOL Test'';
  4535 
  4536 * system: smart selection of Isabelle process versus Isabelle
  4537 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4538 run both "isabelle" and "Isabelle" even if file names are badly
  4539 damaged (executable inspects the case of the first letter of its own
  4540 name); added separate "isabelle-process" and "isabelle-interface";
  4541 
  4542 * system: refrain from any attempt at filtering input streams; no
  4543 longer support ``8bit'' encoding of old isabelle font, instead proper
  4544 iso-latin characters may now be used; the related isatools
  4545 "symbolinput" and "nonascii" have disappeared as well;
  4546 
  4547 * system: removed old "xterm" interface (the print modes "xterm" and
  4548 "xterm_color" are still available for direct use in a suitable
  4549 terminal);
  4550 
  4551 
  4552 
  4553 New in Isabelle99-2 (February 2001)
  4554 -----------------------------------
  4555 
  4556 *** Overview of INCOMPATIBILITIES ***
  4557 
  4558 * HOL: please note that theories in the Library and elsewhere often use the
  4559 new-style (Isar) format; to refer to their theorems in an ML script you must
  4560 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4561 
  4562 * HOL: inductive package no longer splits induction rule aggressively,
  4563 but only as far as specified by the introductions given; the old
  4564 format may be recovered via ML function complete_split_rule or attribute
  4565 'split_rule (complete)';
  4566 
  4567 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4568 gfp_Tarski to gfp_unfold;
  4569 
  4570 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4571 
  4572 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4573 relation); infix "^^" has been renamed "``"; infix "``" has been
  4574 renamed "`"; "univalent" has been renamed "single_valued";
  4575 
  4576 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4577 operation;
  4578 
  4579 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4580 
  4581 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4582 
  4583 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4584 consequence, it is no longer monotonic wrt. the local goal context
  4585 (which is now passed through the inductive cases);
  4586 
  4587 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4588 \<gg> to \<ggreater>;
  4589 
  4590 
  4591 *** Document preparation ***
  4592 
  4593 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4594 available: are "it" for near math-mode best-style output, "sl" for
  4595 slanted text style, and "tt" for plain type-writer; if no
  4596 \isabellestyle command is given, output is according to slanted
  4597 type-writer);
  4598 
  4599 * support sub/super scripts (for single symbols only), input syntax is
  4600 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4601 
  4602 * some more standard symbols; see Appendix A of the system manual for
  4603 the complete list of symbols defined in isabellesym.sty;
  4604 
  4605 * improved isabelle style files; more abstract symbol implementation
  4606 (should now use \isamath{...} and \isatext{...} in custom symbol
  4607 definitions);
  4608 
  4609 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4610 state; Note that presentation of goal states does not conform to
  4611 actual human-readable proof documents.  Please do not include goal
  4612 states into document output unless you really know what you are doing!
  4613 
  4614 * proper indentation of antiquoted output with proportional LaTeX
  4615 fonts;
  4616 
  4617 * no_document ML operator temporarily disables LaTeX document
  4618 generation;
  4619 
  4620 * isatool unsymbolize tunes sources for plain ASCII communication;
  4621 
  4622 
  4623 *** Isar ***
  4624 
  4625 * Pure: Isar now suffers initial goal statements to contain unbound
  4626 schematic variables (this does not conform to actual readable proof
  4627 documents, due to unpredictable outcome and non-compositional proof
  4628 checking); users who know what they are doing may use schematic goals
  4629 for Prolog-style synthesis of proven results;
  4630 
  4631 * Pure: assumption method (an implicit finishing) now handles actual
  4632 rules as well;
  4633 
  4634 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4635 initial goal, declare "that" only as Pure intro (only for single
  4636 steps); the "that" rule assumption may now be involved in implicit
  4637 finishing, thus ".." becomes a feasible for trivial obtains;
  4638 
  4639 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4640 instance proofs may be performed by "..";
  4641 
  4642 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4643 statements as well;
  4644 
  4645 * Pure: more robust selection of calculational rules;
  4646 
  4647 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4648 rule (as well as the assumption rule);
  4649 
  4650 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4651 lemmas, using the graph browser tool;
  4652 
  4653 * Pure: predict failure of "show" in interactive mode;
  4654 
  4655 * Pure: 'thms_containing' now takes actual terms as arguments;
  4656 
  4657 * HOL: improved method 'induct' --- now handles non-atomic goals
  4658 (potential INCOMPATIBILITY); tuned error handling;
  4659 
  4660 * HOL: cases and induct rules now provide explicit hints about the
  4661 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4662 any remaining facts are inserted into the goal verbatim;
  4663 
  4664 * HOL: local contexts (aka cases) may now contain term bindings as
  4665 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4666 the result to be shown in each case;
  4667 
  4668 * HOL: added 'recdef_tc' command;
  4669 
  4670 * isatool convert assists in eliminating legacy ML scripts;
  4671 
  4672 
  4673 *** HOL ***
  4674 
  4675 * HOL/Library: a collection of generic theories to be used together
  4676 with main HOL; the theory loader path already includes this directory
  4677 by default; the following existing theories have been moved here:
  4678 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4679 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4680 
  4681 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4682 modelling and verification task performed in Isabelle/HOL +
  4683 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4684 
  4685 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4686 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4687 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4688 'domain', this makes the theory consistent with mathematical
  4689 literature;
  4690 
  4691 * HOL basics: added overloaded operations "inverse" and "divide"
  4692 (infix "/"), syntax for generic "abs" operation, generic summation
  4693 operator \<Sum>;
  4694 
  4695 * HOL/typedef: simplified package, provide more useful rules (see also
  4696 HOL/subset.thy);
  4697 
  4698 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4699 now expressed as a proper nested rule (old-style tactic scripts may
  4700 require atomize_strip_tac to cope with non-atomic premises);
  4701 
  4702 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4703 to "split_conv" (old name still available for compatibility);
  4704 
  4705 * HOL: improved concrete syntax for strings (e.g. allows translation
  4706 rules with string literals);
  4707 
  4708 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4709  and Fleuriot's mechanization of analysis, including the transcendental
  4710  functions for the reals;
  4711 
  4712 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4713 
  4714 
  4715 *** CTT ***
  4716 
  4717 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4718 "lam" is displayed as TWO lambda-symbols
  4719 
  4720 * CTT: theory Main now available, containing everything (that is, Bool
  4721 and Arith);
  4722 
  4723 
  4724 *** General ***
  4725 
  4726 * Pure: the Simplifier has been implemented properly as a derived rule
  4727 outside of the actual kernel (at last!); the overall performance
  4728 penalty in practical applications is about 50%, while reliability of
  4729 the Isabelle inference kernel has been greatly improved;
  4730 
  4731 * print modes "brackets" and "no_brackets" control output of nested =>
  4732 (types) and ==> (props); the default behaviour is "brackets";
  4733 
  4734 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4735 as assumptions as well;
  4736 
  4737 * system: support Poly/ML 4.0;
  4738 
  4739 * system: isatool install handles KDE version 1 or 2;
  4740 
  4741 
  4742 
  4743 New in Isabelle99-1 (October 2000)
  4744 ----------------------------------
  4745 
  4746 *** Overview of INCOMPATIBILITIES ***
  4747 
  4748 * HOL: simplification of natural numbers is much changed; to partly
  4749 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4750 issue the following ML commands:
  4751 
  4752   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4753   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4754 
  4755 * HOL: simplification no longer dives into case-expressions; this is
  4756 controlled by "t.weak_case_cong" for each datatype t;
  4757 
  4758 * HOL: nat_less_induct renamed to less_induct;
  4759 
  4760 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4761 fixsome to patch .thy and .ML sources automatically;
  4762 
  4763   select_equality  -> some_equality
  4764   select_eq_Ex     -> some_eq_ex
  4765   selectI2EX       -> someI2_ex
  4766   selectI2         -> someI2
  4767   selectI          -> someI
  4768   select1_equality -> some1_equality
  4769   Eps_sym_eq       -> some_sym_eq_trivial
  4770   Eps_eq           -> some_eq_trivial
  4771 
  4772 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4773 
  4774 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4775 instead);
  4776 
  4777 * HOL: the recursion equations generated by 'recdef' are now called
  4778 f.simps instead of f.rules;
  4779 
  4780 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4781 
  4782 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4783 sometimes be needed;
  4784 
  4785 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4786 
  4787 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4788 
  4789 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4790 product is now "<*>" instead of "Times"; the lexicographic product is
  4791 now "<*lex*>" instead of "**";
  4792 
  4793 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4794 of main HOL, but was unused); better use HOL's datatype package;
  4795 
  4796 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4797 the old syntax may be recovered as follows:
  4798 
  4799   syntax (symbols)
  4800     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4801       (infixl "\\<oplus>" 100)
  4802 
  4803 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4804 
  4805 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4806 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4807 internally;
  4808 
  4809 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4810 changed from A/r to A//r;
  4811 
  4812 * ZF: new treatment of arithmetic (nat & int) may break some old
  4813 proofs;
  4814 
  4815 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4816 rulify -> rule_format, elimify -> elim_format, ...);
  4817 
  4818 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4819 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4820 should have to change intro!! to intro? only); replaced "delrule" by
  4821 "rule del";
  4822 
  4823 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4824 
  4825 * Provers: strengthened force_tac by using new first_best_tac;
  4826 
  4827 * LaTeX document preparation: several changes of isabelle.sty (see
  4828 lib/texinputs);
  4829 
  4830 
  4831 *** Document preparation ***
  4832 
  4833 * formal comments (text blocks etc.) in new-style theories may now
  4834 contain antiquotations of thm/prop/term/typ/text to be presented
  4835 according to latex print mode; concrete syntax is like this:
  4836 @{term[show_types] "f(x) = a + x"};
  4837 
  4838 * isatool mkdir provides easy setup of Isabelle session directories,
  4839 including proper document sources;
  4840 
  4841 * generated LaTeX sources are now deleted after successful run
  4842 (isatool document -c); may retain a copy somewhere else via -D option
  4843 of isatool usedir;
  4844 
  4845 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4846 style files, achieving self-contained LaTeX sources and simplifying
  4847 LaTeX debugging;
  4848 
  4849 * old-style theories now produce (crude) LaTeX output as well;
  4850 
  4851 * browser info session directories are now self-contained (may be put
  4852 on WWW server seperately); improved graphs of nested sessions; removed
  4853 graph for 'all sessions';
  4854 
  4855 * several improvements in isabelle style files; \isabellestyle{it}
  4856 produces fake math mode output; \isamarkupheader is now \section by
  4857 default; see lib/texinputs/isabelle.sty etc.;
  4858 
  4859 
  4860 *** Isar ***
  4861 
  4862 * Isar/Pure: local results and corresponding term bindings are now
  4863 subject to Hindley-Milner polymorphism (similar to ML); this
  4864 accommodates incremental type-inference very nicely;
  4865 
  4866 * Isar/Pure: new derived language element 'obtain' supports
  4867 generalized existence reasoning;
  4868 
  4869 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4870 support accumulation of results, without applying any rules yet;
  4871 useful to collect intermediate results without explicit name
  4872 references, and for use with transitivity rules with more than 2
  4873 premises;
  4874 
  4875 * Isar/Pure: scalable support for case-analysis type proofs: new
  4876 'case' language element refers to local contexts symbolically, as
  4877 produced by certain proof methods; internally, case names are attached
  4878 to theorems as "tags";
  4879 
  4880 * Isar/Pure: theory command 'hide' removes declarations from
  4881 class/type/const name spaces;
  4882 
  4883 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4884 indicate potential overloading;
  4885 
  4886 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4887 
  4888 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4889 "{a,b,c}" instead of {a,b,c};
  4890 
  4891 * Isar/Pure now provides its own version of intro/elim/dest
  4892 attributes; useful for building new logics, but beware of confusion
  4893 with the version in Provers/classical;
  4894 
  4895 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4896 case name 'antecedent';
  4897 
  4898 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4899 to the current context is now done automatically);
  4900 
  4901 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4902 for definining proof methods in ML;
  4903 
  4904 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4905 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4906 most cases, one should have to change intro!! to intro? only);
  4907 replaced "delrule" by "rule del";
  4908 
  4909 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4910 'symmetric' attribute (the latter supercedes [RS sym]);
  4911 
  4912 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4913 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4914 well (including splits);
  4915 
  4916 * Isar/Provers: Simplifier and Classical methods now support all kind
  4917 of modifiers used in the past, including 'cong', 'iff', etc.
  4918 
  4919 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4920 of Simplifier and Classical reasoner);
  4921 
  4922 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4923 now support named cases; major packages (inductive, datatype, primrec,
  4924 recdef) support case names and properly name parameters;
  4925 
  4926 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4927 monotonicity conditions are extracted to be proven at end of
  4928 calculations;
  4929 
  4930 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4931 method anyway;
  4932 
  4933 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4934 split_if split_if_asm; datatype package provides theorems foo.splits =
  4935 foo.split foo.split_asm for each datatype;
  4936 
  4937 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4938 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4939 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4940 use "(cases (simplified))" method in proper proof texts);
  4941 
  4942 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4943 
  4944 * Isar: names of theorems etc. may be natural numbers as well;
  4945 
  4946 * Isar: 'pr' command: optional arguments for goals_limit and
  4947 ProofContext.prems_limit; no longer prints theory contexts, but only
  4948 proof states;
  4949 
  4950 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4951 additional print modes to be specified; e.g. "pr(latex)" will print
  4952 proof state according to the Isabelle LaTeX style;
  4953 
  4954 * Isar: improved support for emulating tactic scripts, including proof
  4955 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4956 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4957 (for HOL datatypes);
  4958 
  4959 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4960 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4961 'proof method scripts' have to be in depth-first order;
  4962 
  4963 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4964 
  4965 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4966 should instead use individual commands for printing items
  4967 (print_commands, print_methods etc.);
  4968 
  4969 * Isar: added 'nothing' --- the empty list of theorems;
  4970 
  4971 
  4972 *** HOL ***
  4973 
  4974 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4975 corresponding virtual machine and a specification of its bytecode
  4976 verifier and a lightweight bytecode verifier, including proofs of
  4977 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4978 Cornelia Pusch (see also the homepage of project Bali at
  4979 http://isabelle.in.tum.de/Bali/);
  4980 
  4981 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4982 Clemens Ballarin;
  4983 
  4984 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4985 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4986 Rasmussen;
  4987 
  4988 * HOL/Lattice: fundamental concepts of lattice theory and order
  4989 structures, including duals, properties of bounds versus algebraic
  4990 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4991 Theorem for complete lattices etc.; may also serve as a demonstration
  4992 for abstract algebraic reasoning using axiomatic type classes, and
  4993 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4994 
  4995 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4996 von Oheimb;
  4997 
  4998 * HOL/IMPP: extension of IMP with local variables and mutually
  4999 recursive procedures, by David von Oheimb;
  5000 
  5001 * HOL/Lambda: converted into new-style theory and document;
  5002 
  5003 * HOL/ex/Multiquote: example of multiple nested quotations and
  5004 anti-quotations -- basically a generalized version of de-Bruijn
  5005 representation; very useful in avoiding lifting of operations;
  5006 
  5007 * HOL/record: added general record equality rule to simpset; fixed
  5008 select-update simplification procedure to handle extended records as
  5009 well; admit "r" as field name;
  5010 
  5011 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5012 other numeric types and also as the identity of groups, rings, etc.;
  5013 
  5014 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5015 Types nat and int belong to this axclass;
  5016 
  5017 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5018    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5019    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5020   two terms #m*u and #n*u are replaced by #(m+n)*u
  5021     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5022   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5023     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5024 
  5025 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5026 powerful prover for predicate logic but knows nothing of clasets; see
  5027 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5028 
  5029 * HOL: new version of "case_tac" subsumes both boolean case split and
  5030 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5031 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5032 
  5033 * HOL: simplification no longer dives into case-expressions: only the
  5034 selector expression is simplified, but not the remaining arms; to
  5035 enable full simplification of case-expressions for datatype t, you may
  5036 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5037 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5038 
  5039 * HOL/recdef: the recursion equations generated by 'recdef' for
  5040 function 'f' are now called f.simps instead of f.rules; if all
  5041 termination conditions are proved automatically, these simplification
  5042 rules are added to the simpset, as in primrec; rules may be named
  5043 individually as well, resulting in a separate list of theorems for
  5044 each equation;
  5045 
  5046 * HOL/While is a new theory that provides a while-combinator. It
  5047 permits the definition of tail-recursive functions without the
  5048 provision of a termination measure. The latter is necessary once the
  5049 invariant proof rule for while is applied.
  5050 
  5051 * HOL: new (overloaded) notation for the set of elements below/above
  5052 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5053 
  5054 * HOL: theorems impI, allI, ballI bound as "strip";
  5055 
  5056 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5057 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5058 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5059 
  5060 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5061 
  5062 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5063 main HOL, but was unused);
  5064 
  5065 * HOL: fewer consts declared as global (e.g. have to refer to
  5066 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5067 
  5068 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5069 in case of overlap with user translations (e.g. judgements over
  5070 tuples); (note that the underlying logical represenation is still
  5071 bogus);
  5072 
  5073 
  5074 *** ZF ***
  5075 
  5076 * ZF: simplification automatically cancels common terms in arithmetic
  5077 expressions over nat and int;
  5078 
  5079 * ZF: new treatment of nat to minimize type-checking: all operators
  5080 coerce their operands to a natural number using the function natify,
  5081 making the algebraic laws unconditional;
  5082 
  5083 * ZF: as above, for int: operators coerce their operands to an integer
  5084 using the function intify;
  5085 
  5086 * ZF: the integer library now contains many of the usual laws for the
  5087 orderings, including $<=, and monotonicity laws for $+ and $*;
  5088 
  5089 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5090 simplification;
  5091 
  5092 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5093 to the simplifier and classical reasoner simultaneously;
  5094 
  5095 
  5096 *** General ***
  5097 
  5098 * Provers: blast_tac now handles actual object-logic rules as
  5099 assumptions; note that auto_tac uses blast_tac internally as well;
  5100 
  5101 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5102 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5103 
  5104 * Provers: delrules now handles destruct rules as well (no longer need
  5105 explicit make_elim);
  5106 
  5107 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5108   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5109 use instead the strong form,
  5110   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5111 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5112 from destruct-rules;
  5113 
  5114 * Provers: Simplifier.easy_setup provides a fast path to basic
  5115 Simplifier setup for new object-logics;
  5116 
  5117 * Pure: AST translation rules no longer require constant head on LHS;
  5118 
  5119 * Pure: improved name spaces: ambiguous output is qualified; support
  5120 for hiding of names;
  5121 
  5122 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5123 XSYMBOL_HOME; no longer need to do manual configuration in most
  5124 situations;
  5125 
  5126 * system: compression of ML heaps images may now be controlled via -c
  5127 option of isabelle and isatool usedir (currently only observed by
  5128 Poly/ML);
  5129 
  5130 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5131 useful for remote X11);
  5132 
  5133 * system: provide TAGS file for Isabelle sources;
  5134 
  5135 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5136 order;
  5137 
  5138 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5139 timing flag supersedes proof_timing and Toplevel.trace;
  5140 
  5141 * ML: new combinators |>> and |>>> for incremental transformations
  5142 with secondary results (e.g. certain theory extensions):
  5143 
  5144 * ML: PureThy.add_defs gets additional argument to indicate potential
  5145 overloading (usually false);
  5146 
  5147 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5148 results;
  5149 
  5150 
  5151 
  5152 New in Isabelle99 (October 1999)
  5153 --------------------------------
  5154 
  5155 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5156 
  5157 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5158 are no longer simplified.  (This allows the simplifier to unfold recursive
  5159 functional programs.)  To restore the old behaviour, declare
  5160 
  5161     Delcongs [if_weak_cong];
  5162 
  5163 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5164 complement;
  5165 
  5166 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5167 
  5168 * HOL/datatype: mutual_induct_tac no longer exists --
  5169   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5170 
  5171 * HOL/typedef: fixed type inference for representing set; type
  5172 arguments now have to occur explicitly on the rhs as type constraints;
  5173 
  5174 * ZF: The con_defs part of an inductive definition may no longer refer
  5175 to constants declared in the same theory;
  5176 
  5177 * HOL, ZF: the function mk_cases, generated by the inductive
  5178 definition package, has lost an argument.  To simplify its result, it
  5179 uses the default simpset instead of a supplied list of theorems.
  5180 
  5181 * HOL/List: the constructors of type list are now Nil and Cons;
  5182 
  5183 * Simplifier: the type of the infix ML functions
  5184         setSSolver addSSolver setSolver addSolver
  5185 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5186 for packaging solvers. A solver is created via
  5187         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5188 where the string argument is only a comment.
  5189 
  5190 
  5191 *** Proof tools ***
  5192 
  5193 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5194 decision procedure for linear arithmetic. Currently it is used for
  5195 types `nat', `int', and `real' in HOL (see below); it can, should and
  5196 will be instantiated for other types and logics as well.
  5197 
  5198 * The simplifier now accepts rewrite rules with flexible heads, eg
  5199      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5200   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5201   matching.
  5202 
  5203 
  5204 *** General ***
  5205 
  5206 * New Isabelle/Isar subsystem provides an alternative to traditional
  5207 tactical theorem proving; together with the ProofGeneral/isar user
  5208 interface it offers an interactive environment for developing human
  5209 readable proof documents (Isar == Intelligible semi-automated
  5210 reasoning); for further information see isatool doc isar-ref,
  5211 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5212 
  5213 * improved and simplified presentation of theories: better HTML markup
  5214 (including colors), graph views in several sizes; isatool usedir now
  5215 provides a proper interface for user theories (via -P option); actual
  5216 document preparation based on (PDF)LaTeX is available as well (for
  5217 new-style theories only); see isatool doc system for more information;
  5218 
  5219 * native support for Proof General, both for classic Isabelle and
  5220 Isabelle/Isar;
  5221 
  5222 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5223 using the graph browser tool;
  5224 
  5225 * Isabelle manuals now also available as PDF;
  5226 
  5227 * theory loader rewritten from scratch (may not be fully
  5228 bug-compatible); old loadpath variable has been replaced by show_path,
  5229 add_path, del_path, reset_path functions; new operations such as
  5230 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5231 isatool doc ref);
  5232 
  5233 * improved isatool install: option -k creates KDE application icon,
  5234 option -p DIR installs standalone binaries;
  5235 
  5236 * added ML_PLATFORM setting (useful for cross-platform installations);
  5237 more robust handling of platform specific ML images for SML/NJ;
  5238 
  5239 * the settings environment is now statically scoped, i.e. it is never
  5240 created again in sub-processes invoked from isabelle, isatool, or
  5241 Isabelle;
  5242 
  5243 * path element specification '~~' refers to '$ISABELLE_HOME';
  5244 
  5245 * in locales, the "assumes" and "defines" parts may be omitted if
  5246 empty;
  5247 
  5248 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5249 long arrows);
  5250 
  5251 * new print_mode "HTML";
  5252 
  5253 * new flag show_tags controls display of tags of theorems (which are
  5254 basically just comments that may be attached by some tools);
  5255 
  5256 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5257 mode and goal output format:
  5258 
  5259 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5260 244c244
  5261 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5262 ---
  5263 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5264 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5265 181c181
  5266 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5267 ---
  5268 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5269 
  5270 * function bind_thms stores lists of theorems (cf. bind_thm);
  5271 
  5272 * new shorthand tactics ftac, eatac, datac, fatac;
  5273 
  5274 * qed (and friends) now accept "" as result name; in that case the
  5275 theorem is not stored, but proper checks and presentation of the
  5276 result still apply;
  5277 
  5278 * theorem database now also indexes constants "Trueprop", "all",
  5279 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5280 
  5281 
  5282 *** HOL ***
  5283 
  5284 ** HOL arithmetic **
  5285 
  5286 * There are now decision procedures for linear arithmetic over nat and
  5287 int:
  5288 
  5289 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5290 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5291 are treated as atomic; subformulae not involving type `nat' or `int'
  5292 are ignored; quantified subformulae are ignored unless they are
  5293 positive universal or negative existential. The tactic has to be
  5294 invoked by hand and can be a little bit slow. In particular, the
  5295 running time is exponential in the number of occurrences of `min' and
  5296 `max', and `-' on `nat'.
  5297 
  5298 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5299 (negated) (in)equalities among the premises and the conclusion into
  5300 account (i.e. no compound formulae) and does not know about `min' and
  5301 `max', and `-' on `nat'. It is fast and is used automatically by the
  5302 simplifier.
  5303 
  5304 NB: At the moment, these decision procedures do not cope with mixed
  5305 nat/int formulae where the two parts interact, such as `m < n ==>
  5306 int(m) < int(n)'.
  5307 
  5308 * HOL/Numeral provides a generic theory of numerals (encoded
  5309 efficiently as bit strings); setup for types nat/int/real is in place;
  5310 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5311 int, existing theories and proof scripts may require a few additional
  5312 type constraints;
  5313 
  5314 * integer division and remainder can now be performed on constant
  5315 arguments;
  5316 
  5317 * many properties of integer multiplication, division and remainder
  5318 are now available;
  5319 
  5320 * An interface to the Stanford Validity Checker (SVC) is available through the
  5321 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5322 are proved automatically.  SVC must be installed separately, and its results
  5323 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5324 invocation of the underlying oracle).  For SVC see
  5325   http://verify.stanford.edu/SVC
  5326 
  5327 * IsaMakefile: the HOL-Real target now builds an actual image;
  5328 
  5329 
  5330 ** HOL misc **
  5331 
  5332 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5333 (in Isabelle/Isar) -- by Gertrud Bauer;
  5334 
  5335 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5336 analysis for assembly languages with subtypes;
  5337 
  5338 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5339 -- avoids syntactic ambiguities and treats state, transition, and
  5340 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5341 changed syntax and (many) tactics;
  5342 
  5343 * HOL/inductive: Now also handles more general introduction rules such
  5344   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5345   theorems are now maintained within the theory (maintained via the
  5346   "mono" attribute);
  5347 
  5348 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5349   (using function types) such as
  5350 
  5351   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5352 
  5353 * HOL/record: record_simproc (part of the default simpset) takes care
  5354 of selectors applied to updated records; record_split_tac is no longer
  5355 part of the default claset; update_defs may now be removed from the
  5356 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5357 
  5358   claset_ref () := claset() addSWrapper record_split_wrapper;
  5359   Delsimprocs [record_simproc]
  5360 
  5361 * HOL/typedef: fixed type inference for representing set; type
  5362 arguments now have to occur explicitly on the rhs as type constraints;
  5363 
  5364 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5365 names rather than an ML expression;
  5366 
  5367 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5368 supplied later.  Program schemes can be defined, such as
  5369     "While B C s = (if B s then While B C (C s) else s)"
  5370 where the well-founded relation can be chosen after B and C have been given.
  5371 
  5372 * HOL/List: the constructors of type list are now Nil and Cons;
  5373 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5374 course, ML tools referring to List.list.op # etc. have to be adapted;
  5375 
  5376 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5377 disabled by default; run isabelle with option -m HOL to get back to
  5378 the original Gordon/HOL-style output;
  5379 
  5380 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5381 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5382 
  5383 * HOL basic syntax simplified (more orthogonal): all variants of
  5384 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5385 Eps operator is provided as well: "SOME x. P[x]";
  5386 
  5387 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5388 
  5389 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5390 thus available for user theories;
  5391 
  5392 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5393 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5394 time;
  5395 
  5396 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5397 several times and then mp;
  5398 
  5399 
  5400 *** LK ***
  5401 
  5402 * the notation <<...>> is now available as a notation for sequences of
  5403 formulas;
  5404 
  5405 * the simplifier is now installed
  5406 
  5407 * the axiom system has been generalized (thanks to Soren Heilmann)
  5408 
  5409 * the classical reasoner now has a default rule database
  5410 
  5411 
  5412 *** ZF ***
  5413 
  5414 * new primrec section allows primitive recursive functions to be given
  5415 directly (as in HOL) over datatypes and the natural numbers;
  5416 
  5417 * new tactics induct_tac and exhaust_tac for induction (or case
  5418 analysis) over datatypes and the natural numbers;
  5419 
  5420 * the datatype declaration of type T now defines the recursor T_rec;
  5421 
  5422 * simplification automatically does freeness reasoning for datatype
  5423 constructors;
  5424 
  5425 * automatic type-inference, with AddTCs command to insert new
  5426 type-checking rules;
  5427 
  5428 * datatype introduction rules are now added as Safe Introduction rules
  5429 to the claset;
  5430 
  5431 * the syntax "if P then x else y" is now available in addition to
  5432 if(P,x,y);
  5433 
  5434 
  5435 *** Internal programming interfaces ***
  5436 
  5437 * tuned simplifier trace output; new flag debug_simp;
  5438 
  5439 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5440 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5441 
  5442 * AxClass.axclass_tac lost the theory argument;
  5443 
  5444 * tuned current_goals_markers semantics: begin / end goal avoids
  5445 printing empty lines;
  5446 
  5447 * removed prs and prs_fn hook, which was broken because it did not
  5448 include \n in its semantics, forcing writeln to add one
  5449 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5450 string -> unit if you really want to output text without newline;
  5451 
  5452 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5453 plain output, interface builders may have to enable 'isabelle_font'
  5454 mode to get Isabelle font glyphs as before;
  5455 
  5456 * refined token_translation interface; INCOMPATIBILITY: output length
  5457 now of type real instead of int;
  5458 
  5459 * theory loader actions may be traced via new ThyInfo.add_hook
  5460 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5461 your own database of information attached to *whole* theories -- as
  5462 opposed to intra-theory data slots offered via TheoryDataFun;
  5463 
  5464 * proper handling of dangling sort hypotheses (at last!);
  5465 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5466 extra sort hypotheses that can be witnessed from the type signature;
  5467 the force_strip_shyps flag is gone, any remaining shyps are simply
  5468 left in the theorem (with a warning issued by strip_shyps_warning);
  5469 
  5470 
  5471 
  5472 New in Isabelle98-1 (October 1998)
  5473 ----------------------------------
  5474 
  5475 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5476 
  5477 * several changes of automated proof tools;
  5478 
  5479 * HOL: major changes to the inductive and datatype packages, including
  5480 some minor incompatibilities of theory syntax;
  5481 
  5482 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5483 called `inj_on';
  5484 
  5485 * HOL: removed duplicate thms in Arith:
  5486   less_imp_add_less  should be replaced by  trans_less_add1
  5487   le_imp_add_le      should be replaced by  trans_le_add1
  5488 
  5489 * HOL: unary minus is now overloaded (new type constraints may be
  5490 required);
  5491 
  5492 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5493 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5494 now taken as an integer constant.
  5495 
  5496 * Pure: ML function 'theory_of' renamed to 'theory';
  5497 
  5498 
  5499 *** Proof tools ***
  5500 
  5501 * Simplifier:
  5502   1. Asm_full_simp_tac is now more aggressive.
  5503      1. It will sometimes reorient premises if that increases their power to
  5504         simplify.
  5505      2. It does no longer proceed strictly from left to right but may also
  5506         rotate premises to achieve further simplification.
  5507      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5508      old Asm_full_simp_tac in that it does not rotate premises.
  5509   2. The simplifier now knows a little bit about nat-arithmetic.
  5510 
  5511 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5512 allows for selected deletion of wrappers, by introduction of names for
  5513 wrapper functionals.  This implies that addbefore, addSbefore,
  5514 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5515 and that adding two tactics with the same name overwrites the first
  5516 one (emitting a warning).
  5517   type wrapper = (int -> tactic) -> (int -> tactic)
  5518   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5519   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5520   delWrapper, delSWrapper: claset *  string            -> claset
  5521   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5522 
  5523 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5524 semantics; addbefore now affects only the unsafe part of step_tac
  5525 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5526 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5527 by Force_tac;
  5528 
  5529 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5530 compWrapper; added safe wrapper (and access functions for it);
  5531 
  5532 * HOL/split_all_tac is now much faster and fails if there is nothing
  5533 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5534 and the names of the automatically generated variables have changed.
  5535 split_all_tac has moved within claset() from unsafe wrappers to safe
  5536 wrappers, which means that !!-bound variables are split much more
  5537 aggressively, and safe_tac and clarify_tac now split such variables.
  5538 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5539 Note: the same holds for record_split_tac, which does the job of
  5540 split_all_tac for record fields.
  5541 
  5542 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5543 permanently to the default simpset using Addsplits just like
  5544 Addsimps. They can be removed via Delsplits just like
  5545 Delsimps. Lower-case versions are also available.
  5546 
  5547 * HOL/Simplifier: The rule split_if is now part of the default
  5548 simpset. This means that the simplifier will eliminate all occurrences
  5549 of if-then-else in the conclusion of a goal. To prevent this, you can
  5550 either remove split_if completely from the default simpset by
  5551 `Delsplits [split_if]' or remove it in a specific call of the
  5552 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5553 other case splitting rules to/from the default simpset: every datatype
  5554 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5555 t is the name of the datatype).
  5556 
  5557 * Classical reasoner / Simplifier combination: new force_tac (and
  5558 derivatives Force_tac, force) combines rewriting and classical
  5559 reasoning (and whatever other tools) similarly to auto_tac, but is
  5560 aimed to solve the given subgoal completely.
  5561 
  5562 
  5563 *** General ***
  5564 
  5565 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5566 and `goalw': the theory is no longer needed as an explicit argument -
  5567 the current theory context is used; assumptions are no longer returned
  5568 at the ML-level unless one of them starts with ==> or !!; it is
  5569 recommended to convert to these new commands using isatool fixgoal
  5570 (backup your sources first!);
  5571 
  5572 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5573 the current theory context, and 'theory' to lookup stored theories;
  5574 
  5575 * new theory section 'locale' for declaring constants, assumptions and
  5576 definitions that have local scope;
  5577 
  5578 * new theory section 'nonterminals' for purely syntactic types;
  5579 
  5580 * new theory section 'setup' for generic ML setup functions
  5581 (e.g. package initialization);
  5582 
  5583 * the distribution now includes Isabelle icons: see
  5584 lib/logo/isabelle-{small,tiny}.xpm;
  5585 
  5586 * isatool install - install binaries with absolute references to
  5587 ISABELLE_HOME/bin;
  5588 
  5589 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5590 
  5591 * print mode 'emacs' reserved for Isamode;
  5592 
  5593 * support multiple print (ast) translations per constant name;
  5594 
  5595 * theorems involving oracles are now printed with a suffixed [!];
  5596 
  5597 
  5598 *** HOL ***
  5599 
  5600 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5601 
  5602 * HOL/inductive package reorganized and improved: now supports mutual
  5603 definitions such as
  5604 
  5605   inductive EVEN ODD
  5606     intrs
  5607       null "0 : EVEN"
  5608       oddI "n : EVEN ==> Suc n : ODD"
  5609       evenI "n : ODD ==> Suc n : EVEN"
  5610 
  5611 new theorem list "elims" contains an elimination rule for each of the
  5612 recursive sets; inductive definitions now handle disjunctive premises
  5613 correctly (also ZF);
  5614 
  5615 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5616 "mutual_induct" no longer exists - the induction rule is always
  5617 contained in "induct";
  5618 
  5619 
  5620 * HOL/datatype package re-implemented and greatly improved: now
  5621 supports mutually recursive datatypes such as
  5622 
  5623   datatype
  5624     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5625             | SUM ('a aexp) ('a aexp)
  5626             | DIFF ('a aexp) ('a aexp)
  5627             | NUM 'a
  5628   and
  5629     'a bexp = LESS ('a aexp) ('a aexp)
  5630             | AND ('a bexp) ('a bexp)
  5631             | OR ('a bexp) ('a bexp)
  5632 
  5633 as well as indirectly recursive datatypes such as
  5634 
  5635   datatype
  5636     ('a, 'b) term = Var 'a
  5637                   | App 'b ((('a, 'b) term) list)
  5638 
  5639 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5640 induction on mutually / indirectly recursive datatypes.
  5641 
  5642 Primrec equations are now stored in theory and can be accessed via
  5643 <function_name>.simps.
  5644 
  5645 INCOMPATIBILITIES:
  5646 
  5647   - Theories using datatypes must now have theory Datatype as an
  5648     ancestor.
  5649   - The specific <typename>.induct_tac no longer exists - use the
  5650     generic induct_tac instead.
  5651   - natE has been renamed to nat.exhaust - use exhaust_tac
  5652     instead of res_inst_tac ... natE. Note that the variable
  5653     names in nat.exhaust differ from the names in natE, this
  5654     may cause some "fragile" proofs to fail.
  5655   - The theorems split_<typename>_case and split_<typename>_case_asm
  5656     have been renamed to <typename>.split and <typename>.split_asm.
  5657   - Since default sorts of type variables are now handled correctly,
  5658     some datatype definitions may have to be annotated with explicit
  5659     sort constraints.
  5660   - Primrec definitions no longer require function name and type
  5661     of recursive argument.
  5662 
  5663 Consider using isatool fixdatatype to adapt your theories and proof
  5664 scripts to the new package (backup your sources first!).
  5665 
  5666 
  5667 * HOL/record package: considerably improved implementation; now
  5668 includes concrete syntax for record types, terms, updates; theorems
  5669 for surjective pairing and splitting !!-bound record variables; proof
  5670 support is as follows:
  5671 
  5672   1) standard conversions (selectors or updates applied to record
  5673 constructor terms) are part of the standard simpset;
  5674 
  5675   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5676 made part of standard simpset and claset via addIffs;
  5677 
  5678   3) a tactic for record field splitting (record_split_tac) is part of
  5679 the standard claset (addSWrapper);
  5680 
  5681 To get a better idea about these rules you may retrieve them via
  5682 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5683 the name of your record type.
  5684 
  5685 The split tactic 3) conceptually simplifies by the following rule:
  5686 
  5687   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5688 
  5689 Thus any record variable that is bound by meta-all will automatically
  5690 blow up into some record constructor term, consequently the
  5691 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5692 solve record problems automatically.
  5693 
  5694 
  5695 * reorganized the main HOL image: HOL/Integ and String loaded by
  5696 default; theory Main includes everything;
  5697 
  5698 * automatic simplification of integer sums and comparisons, using cancellation;
  5699 
  5700 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5701 
  5702 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5703 
  5704 * many new identities for unions, intersections, set difference, etc.;
  5705 
  5706 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5707 called split_if, split_split, split_sum_case and split_nat_case (to go
  5708 with add/delsplits);
  5709 
  5710 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5711 (?x::unit) = (); this is made part of the default simpset, which COULD
  5712 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5713 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5714 unit_abs_eta_conv is added in order to counter the effect of
  5715 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5716 %u.f();
  5717 
  5718 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5719 makes more sense);
  5720 
  5721 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5722   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5723   disjointness reasoning but breaking a few old proofs.
  5724 
  5725 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5726 to 'converse' from 'inverse' (for compatibility with ZF and some
  5727 literature);
  5728 
  5729 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5730 the well-founded relation;
  5731 
  5732 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5733     Compl A.  The "Compl" syntax remains available as input syntax for this
  5734     release ONLY.
  5735 
  5736 * HOL/Update: new theory of function updates:
  5737     f(a:=b) == %x. if x=a then b else f x
  5738 may also be iterated as in f(a:=b,c:=d,...);
  5739 
  5740 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5741 
  5742 * HOL/List:
  5743   - new function list_update written xs[i:=v] that updates the i-th
  5744     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5745   - new function `upt' written [i..j(] which generates the list
  5746     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5747     bound write [i..j], which is a shorthand for [i..j+1(].
  5748   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5749 
  5750 * HOL/Arith:
  5751   - removed 'pred' (predecessor) function;
  5752   - generalized some theorems about n-1;
  5753   - many new laws about "div" and "mod";
  5754   - new laws about greatest common divisors (see theory ex/Primes);
  5755 
  5756 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5757 instead of "inverse";
  5758 
  5759 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5760   of the multiset ordering;
  5761 
  5762 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5763   (not included by default);
  5764 
  5765 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5766 
  5767 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5768   programs, i.e. different program variables may have different types.
  5769 
  5770 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5771   [previously, this check worked only if the rewrite rule was unconditional]
  5772   Now rew can involve either definitions or equalities (either == or =).
  5773 
  5774 
  5775 *** ZF ***
  5776 
  5777 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5778   only the theorems proved on ZF.ML;
  5779 
  5780 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5781   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5782   disjointness reasoning but breaking a few old proofs.
  5783 
  5784 * ZF/Update: new theory of function updates
  5785     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5786   may also be iterated as in f(a:=b,c:=d,...);
  5787 
  5788 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5789 
  5790 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5791   [previously, this check worked only if the rewrite rule was unconditional]
  5792   Now rew can involve either definitions or equalities (either == or =).
  5793 
  5794 * case_tac provided for compatibility with HOL
  5795     (like the old excluded_middle_tac, but with subgoals swapped)
  5796 
  5797 
  5798 *** Internal programming interfaces ***
  5799 
  5800 * Pure: several new basic modules made available for general use, see
  5801 also src/Pure/README;
  5802 
  5803 * improved the theory data mechanism to support encapsulation (data
  5804 kind name replaced by private Object.kind, acting as authorization
  5805 key); new type-safe user interface via functor TheoryDataFun; generic
  5806 print_data function becomes basically useless;
  5807 
  5808 * removed global_names compatibility flag -- all theory declarations
  5809 are qualified by default;
  5810 
  5811 * module Pure/Syntax now offers quote / antiquote translation
  5812 functions (useful for Hoare logic etc. with implicit dependencies);
  5813 see HOL/ex/Antiquote for an example use;
  5814 
  5815 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5816 cterm -> thm;
  5817 
  5818 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5819 subgoal;
  5820 
  5821 * Display.print_goals function moved to Locale.print_goals;
  5822 
  5823 * standard print function for goals supports current_goals_markers
  5824 variable for marking begin of proof, end of proof, start of goal; the
  5825 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5826 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5827 for example;
  5828 
  5829 
  5830 
  5831 New in Isabelle98 (January 1998)
  5832 --------------------------------
  5833 
  5834 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5835 
  5836 * changed lexical syntax of terms / types: dots made part of long
  5837 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5838 
  5839 * simpset (and claset) reference variable replaced by functions
  5840 simpset / simpset_ref;
  5841 
  5842 * no longer supports theory aliases (via merge) and non-trivial
  5843 implicit merge of thms' signatures;
  5844 
  5845 * most internal names of constants changed due to qualified names;
  5846 
  5847 * changed Pure/Sequence interface (see Pure/seq.ML);
  5848 
  5849 
  5850 *** General Changes ***
  5851 
  5852 * hierachically structured name spaces (for consts, types, axms, thms
  5853 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5854 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5855 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5856 long_names for fully qualified output names; NOTE: ML programs
  5857 (special tactics, packages etc.) referring to internal names may have
  5858 to be adapted to cope with fully qualified names; in case of severe
  5859 backward campatibility problems try setting 'global_names' at compile
  5860 time to have enrything declared within a flat name space; one may also
  5861 fine tune name declarations in theories via the 'global' and 'local'
  5862 section;
  5863 
  5864 * reimplemented the implicit simpset and claset using the new anytype
  5865 data filed in signatures; references simpset:simpset ref etc. are
  5866 replaced by functions simpset:unit->simpset and
  5867 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5868 to patch your ML files accordingly;
  5869 
  5870 * HTML output now includes theory graph data for display with Java
  5871 applet or isatool browser; data generated automatically via isatool
  5872 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5873 
  5874 * defs may now be conditional; improved rewrite_goals_tac to handle
  5875 conditional equations;
  5876 
  5877 * defs now admits additional type arguments, using TYPE('a) syntax;
  5878 
  5879 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5880 creates a new theory node; implicit merge of thms' signatures is
  5881 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5882 transfer:theory->thm->thm in (rare) cases;
  5883 
  5884 * improved handling of draft signatures / theories; draft thms (and
  5885 ctyps, cterms) are automatically promoted to real ones;
  5886 
  5887 * slightly changed interfaces for oracles: admit many per theory, named
  5888 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5889 
  5890 * print_goals: optional output of const types (set show_consts and
  5891 show_types);
  5892 
  5893 * improved output of warnings (###) and errors (***);
  5894 
  5895 * subgoal_tac displays a warning if the new subgoal has type variables;
  5896 
  5897 * removed old README and Makefiles;
  5898 
  5899 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5900 
  5901 * removed obsolete init_pps and init_database;
  5902 
  5903 * deleted the obsolete tactical STATE, which was declared by
  5904     fun STATE tacfun st = tacfun st st;
  5905 
  5906 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5907 (which abbreviates $HOME);
  5908 
  5909 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5910 use isatool fixseq to adapt your ML programs (this works for fully
  5911 qualified references to the Sequence structure only!);
  5912 
  5913 * use_thy no longer requires writable current directory; it always
  5914 reloads .ML *and* .thy file, if either one is out of date;
  5915 
  5916 
  5917 *** Classical Reasoner ***
  5918 
  5919 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5920 tactics that use classical reasoning to simplify a subgoal without
  5921 splitting it into several subgoals;
  5922 
  5923 * Safe_tac: like safe_tac but uses the default claset;
  5924 
  5925 
  5926 *** Simplifier ***
  5927 
  5928 * added simplification meta rules:
  5929     (asm_)(full_)simplify: simpset -> thm -> thm;
  5930 
  5931 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5932 logics (again);
  5933 
  5934 * added prems argument to simplification procedures;
  5935 
  5936 * HOL, FOL, ZF: added infix function `addsplits':
  5937   instead of `<simpset> setloop (split_tac <thms>)'
  5938   you can simply write `<simpset> addsplits <thms>'
  5939 
  5940 
  5941 *** Syntax ***
  5942 
  5943 * TYPE('a) syntax for type reflection terms;
  5944 
  5945 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5946 
  5947 * pretty printer: changed order of mixfix annotation preference (again!);
  5948 
  5949 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5950 
  5951 
  5952 *** HOL ***
  5953 
  5954 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5955   with `addloop' of the simplifier to faciliate case splitting in premises.
  5956 
  5957 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5958 
  5959 * HOL/Auth: new protocol proofs including some for the Internet
  5960   protocol TLS;
  5961 
  5962 * HOL/Map: new theory of `maps' a la VDM;
  5963 
  5964 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5965 cancelling out common nat summands from =, <, <= (in)equalities, or
  5966 differences; simplification procedures nat_cancel_factor for
  5967 cancelling common factor from =, <, <= (in)equalities over natural
  5968 sums; nat_cancel contains both kinds of procedures, it is installed by
  5969 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5970 
  5971 * HOL/simplifier: terms of the form
  5972   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5973   are rewritten to
  5974   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5975   and those of the form
  5976   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5977   are rewritten to
  5978   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5979 
  5980 * HOL/datatype
  5981   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5982 
  5983   P(t_case f1 ... fn x) =
  5984      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5985         ...
  5986        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5987      )
  5988 
  5989   and a theorem `split_t_case_asm' of the form
  5990 
  5991   P(t_case f1 ... fn x) =
  5992     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5993         ...
  5994        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5995      )
  5996   which can be added to a simpset via `addsplits'. The existing theorems
  5997   expand_list_case and expand_option_case have been renamed to
  5998   split_list_case and split_option_case.
  5999 
  6000 * HOL/Arithmetic:
  6001   - `pred n' is automatically converted to `n-1'.
  6002     Users are strongly encouraged not to use `pred' any longer,
  6003     because it will disappear altogether at some point.
  6004   - Users are strongly encouraged to write "0 < n" rather than
  6005     "n ~= 0". Theorems and proof tools have been modified towards this
  6006     `standard'.
  6007 
  6008 * HOL/Lists:
  6009   the function "set_of_list" has been renamed "set" (and its theorems too);
  6010   the function "nth" now takes its arguments in the reverse order and
  6011   has acquired the infix notation "!" as in "xs!n".
  6012 
  6013 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6014 
  6015 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6016   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6017 
  6018 * HOL/record: extensible records with schematic structural subtyping
  6019 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6020 still lacks various theorems and concrete record syntax;
  6021 
  6022 
  6023 *** HOLCF ***
  6024 
  6025 * removed "axioms" and "generated by" sections;
  6026 
  6027 * replaced "ops" section by extended "consts" section, which is capable of
  6028   handling the continuous function space "->" directly;
  6029 
  6030 * domain package:
  6031   . proves theorems immediately and stores them in the theory,
  6032   . creates hierachical name space,
  6033   . now uses normal mixfix annotations (instead of cinfix...),
  6034   . minor changes to some names and values (for consistency),
  6035   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6036   . separator between mutual domain defs: changed "," to "and",
  6037   . improved handling of sort constraints;  now they have to
  6038     appear on the left-hand side of the equations only;
  6039 
  6040 * fixed LAM <x,y,zs>.b syntax;
  6041 
  6042 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6043 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6044 
  6045 
  6046 *** FOL and ZF ***
  6047 
  6048 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6049   with `addloop' of the simplifier to faciliate case splitting in premises.
  6050 
  6051 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6052 in HOL, they strip ALL and --> from proved theorems;
  6053 
  6054 
  6055 
  6056 New in Isabelle94-8 (May 1997)
  6057 ------------------------------
  6058 
  6059 *** General Changes ***
  6060 
  6061 * new utilities to build / run / maintain Isabelle etc. (in parts
  6062 still somewhat experimental); old Makefiles etc. still functional;
  6063 
  6064 * new 'Isabelle System Manual';
  6065 
  6066 * INSTALL text, together with ./configure and ./build scripts;
  6067 
  6068 * reimplemented type inference for greater efficiency, better error
  6069 messages and clean internal interface;
  6070 
  6071 * prlim command for dealing with lots of subgoals (an easier way of
  6072 setting goals_limit);
  6073 
  6074 
  6075 *** Syntax ***
  6076 
  6077 * supports alternative (named) syntax tables (parser and pretty
  6078 printer); internal interface is provided by add_modesyntax(_i);
  6079 
  6080 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6081 be used in conjunction with the Isabelle symbol font; uses the
  6082 "symbols" syntax table;
  6083 
  6084 * added token_translation interface (may translate name tokens in
  6085 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6086 the current print_mode); IMPORTANT: user print translation functions
  6087 are responsible for marking newly introduced bounds
  6088 (Syntax.mark_boundT);
  6089 
  6090 * token translations for modes "xterm" and "xterm_color" that display
  6091 names in bold, underline etc. or colors (which requires a color
  6092 version of xterm);
  6093 
  6094 * infixes may now be declared with names independent of their syntax;
  6095 
  6096 * added typed_print_translation (like print_translation, but may
  6097 access type of constant);
  6098 
  6099 
  6100 *** Classical Reasoner ***
  6101 
  6102 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6103 some limitations.  Blast_tac...
  6104   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6105   + ignores elimination rules that don't have the correct format
  6106         (the conclusion MUST be a formula variable)
  6107   + ignores types, which can make HOL proofs fail
  6108   + rules must not require higher-order unification, e.g. apply_type in ZF
  6109     [message "Function Var's argument not a bound variable" relates to this]
  6110   + its proof strategy is more general but can actually be slower
  6111 
  6112 * substitution with equality assumptions no longer permutes other
  6113 assumptions;
  6114 
  6115 * minor changes in semantics of addafter (now called addaltern); renamed
  6116 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6117 (and access functions for it);
  6118 
  6119 * improved combination of classical reasoner and simplifier:
  6120   + functions for handling clasimpsets
  6121   + improvement of addss: now the simplifier is called _after_ the
  6122     safe steps.
  6123   + safe variant of addss called addSss: uses safe simplifications
  6124     _during_ the safe steps. It is more complete as it allows multiple
  6125     instantiations of unknowns (e.g. with slow_tac).
  6126 
  6127 *** Simplifier ***
  6128 
  6129 * added interface for simplification procedures (functions that
  6130 produce *proven* rewrite rules on the fly, depending on current
  6131 redex);
  6132 
  6133 * ordering on terms as parameter (used for ordered rewriting);
  6134 
  6135 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6136 
  6137 * the solver is now split into a safe and an unsafe part.
  6138 This should be invisible for the normal user, except that the
  6139 functions setsolver and addsolver have been renamed to setSolver and
  6140 addSolver; added safe_asm_full_simp_tac;
  6141 
  6142 
  6143 *** HOL ***
  6144 
  6145 * a generic induction tactic `induct_tac' which works for all datatypes and
  6146 also for type `nat';
  6147 
  6148 * a generic case distinction tactic `exhaust_tac' which works for all
  6149 datatypes and also for type `nat';
  6150 
  6151 * each datatype comes with a function `size';
  6152 
  6153 * patterns in case expressions allow tuple patterns as arguments to
  6154 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6155 
  6156 * primrec now also works with type nat;
  6157 
  6158 * recdef: a new declaration form, allows general recursive functions to be
  6159 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6160 
  6161 * the constant for negation has been renamed from "not" to "Not" to
  6162 harmonize with FOL, ZF, LK, etc.;
  6163 
  6164 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6165 infinite lists;
  6166 
  6167 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6168 
  6169 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6170 problems in commutative rings, using axiomatic type classes for + and *;
  6171 
  6172 * more examples in HOL/MiniML and HOL/Auth;
  6173 
  6174 * more default rewrite rules for quantifiers, union/intersection;
  6175 
  6176 * a new constant `arbitrary == @x.False';
  6177 
  6178 * HOLCF/IOA replaces old HOL/IOA;
  6179 
  6180 * HOLCF changes: derived all rules and arities
  6181   + axiomatic type classes instead of classes
  6182   + typedef instead of faking type definitions
  6183   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6184   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6185   + eliminated the types void, one, tr
  6186   + use unit lift and bool lift (with translations) instead of one and tr
  6187   + eliminated blift from Lift3.thy (use Def instead of blift)
  6188   all eliminated rules are derived as theorems --> no visible changes ;
  6189 
  6190 
  6191 *** ZF ***
  6192 
  6193 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  6194 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  6195 as ZF_cs addSIs [equalityI];
  6196 
  6197 
  6198 
  6199 New in Isabelle94-7 (November 96)
  6200 ---------------------------------
  6201 
  6202 * allowing negative levels (as offsets) in prlev and choplev;
  6203 
  6204 * super-linear speedup for large simplifications;
  6205 
  6206 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  6207 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  6208 FAIL); can suppress it using the command Delsimps (ex_simps @
  6209 all_simps); De Morgan laws are also now included, by default;
  6210 
  6211 * improved printing of ==>  :  ~:
  6212 
  6213 * new object-logic "Sequents" adds linear logic, while replacing LK
  6214 and Modal (thanks to Sara Kalvala);
  6215 
  6216 * HOL/Auth: correctness proofs for authentication protocols;
  6217 
  6218 * HOL: new auto_tac combines rewriting and classical reasoning (many
  6219 examples on HOL/Auth);
  6220 
  6221 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  6222 the rewriter and classical reasoner simultaneously;
  6223 
  6224 * function uresult no longer returns theorems in "standard" format;
  6225 regain previous version by: val uresult = standard o uresult;
  6226 
  6227 
  6228 
  6229 New in Isabelle94-6
  6230 -------------------
  6231 
  6232 * oracles -- these establish an interface between Isabelle and trusted
  6233 external reasoners, which may deliver results as theorems;
  6234 
  6235 * proof objects (in particular record all uses of oracles);
  6236 
  6237 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  6238 
  6239 * "constdefs" section in theory files;
  6240 
  6241 * "primrec" section (HOL) no longer requires names;
  6242 
  6243 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  6244 
  6245 
  6246 
  6247 New in Isabelle94-5
  6248 -------------------
  6249 
  6250 * reduced space requirements;
  6251 
  6252 * automatic HTML generation from theories;
  6253 
  6254 * theory files no longer require "..." (quotes) around most types;
  6255 
  6256 * new examples, including two proofs of the Church-Rosser theorem;
  6257 
  6258 * non-curried (1994) version of HOL is no longer distributed;
  6259 
  6260 
  6261 
  6262 New in Isabelle94-4