NEWS
author wenzelm
Thu Apr 02 13:41:02 2009 +0200 (2009-04-02)
changeset 30845 9a887484de53
parent 30741 9e23e3ea7edd
child 30847 dd9a1662413b
permissions -rw-r--r--
misc cleanup and rearrangements for Isabelle2009 release;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2009 (April 2009)
     5 --------------------------------
     6 
     7 *** General ***
     8 
     9 * Simplified main Isabelle executables, with less surprises on
    10 case-insensitive file-systems (such as Mac OS).
    11 
    12   - The main Isabelle tool wrapper is now called "isabelle" instead of
    13     "isatool."
    14 
    15   - The former "isabelle" alias for "isabelle-process" has been
    16     removed (should rarely occur to regular users).
    17 
    18   - The former "isabelle-interface" and its alias "Isabelle" have been
    19     removed (interfaces are now regular Isabelle tools).
    20 
    21 Within scripts and make files, the Isabelle environment variables
    22 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
    23 respectively.  (The latter are still available as legacy feature.)
    24 
    25 The old isabelle-interface wrapper could react in confusing ways if
    26 the interface was uninstalled or changed otherwise.  Individual
    27 interface tool configuration is now more explicit, see also the
    28 Isabelle system manual.  In particular, Proof General is now available
    29 via "isabelle emacs".
    30 
    31 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
    32 purge installed copies of Isabelle executables and re-run "isabelle
    33 install -p ...", or use symlinks.
    34 
    35 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
    36 old ~/isabelle, which was slightly non-standard and apt to cause
    37 surprises on case-insensitive file-systems (such as Mac OS).
    38 
    39 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
    40 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
    41 care is required when using older releases of Isabelle.  Note that
    42 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
    43 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
    44 
    45 * Proofs of fully specified statements are run in parallel on
    46 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
    47 a regular 4-core machine, if the initial heap space is made reasonably
    48 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
    49 
    50 * The main reference manuals ("isar-ref", "implementation", and
    51 "system") have been updated and extended.  Formally checked references
    52 as hyperlinks are now available uniformly.
    53 
    54 
    55 
    56 *** Pure ***
    57 
    58 * Complete re-implementation of locales.  INCOMPATIBILITY in several
    59 respects.  The most important changes are listed below.  See the
    60 Tutorial on Locales ("locales" manual) for details.
    61 
    62 - In locale expressions, instantiation replaces renaming.  Parameters
    63 must be declared in a for clause.  To aid compatibility with previous
    64 parameter inheritance, in locale declarations, parameters that are not
    65 'touched' (instantiation position "_" or omitted) are implicitly added
    66 with their syntax at the beginning of the for clause.
    67 
    68 - Syntax from abbreviations and definitions in locales is available in
    69 locale expressions and context elements.  The latter is particularly
    70 useful in locale declarations.
    71 
    72 - More flexible mechanisms to qualify names generated by locale
    73 expressions.  Qualifiers (prefixes) may be specified in locale
    74 expressions, and can be marked as mandatory (syntax: "name!:") or
    75 optional (syntax "name?:").  The default depends for plain "name:"
    76 depends on the situation where a locale expression is used: in
    77 commands 'locale' and 'sublocale' prefixes are optional, in
    78 'interpretation' and 'interpret' prefixes are mandatory.  The old
    79 implicit qualifiers derived from the parameter names of a locale are
    80 no longer generated.
    81 
    82 - Command "sublocale l < e" replaces "interpretation l < e".  The
    83 instantiation clause in "interpretation" and "interpret" (square
    84 brackets) is no longer available.  Use locale expressions.
    85 
    86 - When converting proof scripts, mandatory qualifiers in
    87 'interpretation' and 'interpret' should be retained by default, even
    88 if this is an INCOMPATIBILITY compared to former behavior.  In the
    89 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
    90 in locale expressions range over a single locale instance only.
    91 
    92 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
    93 In existing theorem specifications replace the includes element by the
    94 respective context elements of the included locale, omitting those
    95 that are already present in the theorem specification.  Multiple
    96 assume elements of a locale should be replaced by a single one
    97 involving the locale predicate.  In the proof body, declarations (most
    98 notably theorems) may be regained by interpreting the respective
    99 locales in the proof context as required (command "interpret").
   100 
   101 If using "includes" in replacement of a target solely because the
   102 parameter types in the theorem are not as general as in the target,
   103 consider declaring a new locale with additional type constraints on
   104 the parameters (context element "constrains").
   105 
   106 - Discontinued "locale (open)".  INCOMPATIBILITY.
   107 
   108 - Locale interpretation commands no longer attempt to simplify goal.
   109 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   110 methods intro_locales and unfold_locales to clarify.
   111 
   112 - Locale interpretation commands no longer accept interpretation
   113 attributes.  INCOMPATIBILITY.
   114 
   115 * Class declaration: so-called "base sort" must not be given in import
   116 list any longer, but is inferred from the specification.  Particularly
   117 in HOL, write
   118 
   119     class foo = ...
   120 
   121 instead of
   122 
   123     class foo = type + ...
   124 
   125 * Class target: global versions of theorems stemming do not carry a
   126 parameter prefix any longer.  INCOMPATIBILITY.
   127 
   128 * Class 'instance' command no longer accepts attached definitions.
   129 INCOMPATIBILITY, use proper 'instantiation' target instead.
   130 
   131 * Recovered hiding of consts, which was accidentally broken in
   132 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   133 makes c inaccessible; consider using ``hide (open) const c'' instead.
   134 
   135 * Slightly more coherent Pure syntax, with updated documentation in
   136 isar-ref manual.  Removed locales meta_term_syntax and
   137 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   138 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   139 directly in regular applications.
   140 
   141 * There is a new syntactic category "float_const" for signed decimal
   142 fractions (e.g. 123.45 or -123.45).
   143 
   144 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   145 interface with 'setup' command instead.
   146 
   147 * Command 'local_setup' is similar to 'setup', but operates on a local
   148 theory context.
   149 
   150 * The 'axiomatization' command now only works within a global theory
   151 context.  INCOMPATIBILITY.
   152 
   153 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   154 hypotheses.  Sorts required in the course of reasoning need to be
   155 covered by the constraints in the initial statement, completed by the
   156 type instance information of the background theory.  Non-trivial sort
   157 hypotheses, which rarely occur in practice, may be specified via
   158 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   159 
   160   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   161 
   162 The result contains an implicit sort hypotheses as before --
   163 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   164 normalization.
   165 
   166 * Generalized Isar history, with support for linear undo, direct state
   167 addressing etc.
   168 
   169 * Changed defaults for unify configuration options:
   170 
   171   unify_trace_bound = 50 (formerly 25)
   172   unify_search_bound = 60 (formerly 30)
   173 
   174 * Different bookkeeping for code equations (INCOMPATIBILITY):
   175 
   176   a) On theory merge, the last set of code equations for a particular
   177      constant is taken (in accordance with the policy applied by other
   178      parts of the code generator framework).
   179 
   180   b) Code equations stemming from explicit declarations (e.g. code
   181      attribute) gain priority over default code equations stemming
   182      from definition, primrec, fun etc.
   183 
   184 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   185 
   186 * Unified theorem tables for both code code generators.  Thus [code
   187 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   188 
   189 * Command 'find_consts' searches for constants based on type and name
   190 patterns, e.g.
   191 
   192     find_consts "_ => bool"
   193 
   194 By default, matching is against subtypes, but it may be restricted to
   195 the whole type.  Searching by name is possible.  Multiple queries are
   196 conjunctive and queries may be negated by prefixing them with a
   197 hyphen:
   198 
   199     find_consts strict: "_ => bool" name: "Int" -"int => int"
   200 
   201 * New 'find_theorems' criterion "solves" matches theorems that
   202 directly solve the current goal (modulo higher-order unification).
   203 
   204 * Auto solve feature for main theorem statements: whenever a new goal
   205 is stated, "find_theorems solves" is called; any theorems that could
   206 solve the lemma directly are listed as part of the goal state.
   207 Cf. associated options in Proof General Isabelle settings menu,
   208 enabled by default, with reasonable timeout for pathological cases of
   209 higher-order unification.
   210 
   211 
   212 *** Document preparation ***
   213 
   214 * Antiquotation @{lemma} now imitates a regular terminal proof,
   215 demanding keyword 'by' and supporting the full method expression
   216 syntax just like the Isar command 'by'.
   217 
   218 
   219 *** HOL ***
   220 
   221 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   222 points Main and Complex_Main remain as before.
   223 
   224 * Logic image HOL-Plain provides a minimal HOL with the most important
   225 tools available (inductive, datatype, primrec, ...).  This facilitates
   226 experimentation and tool development.  Note that user applications
   227 (and library theories) should never refer to anything below theory
   228 Main, as before.
   229 
   230 * Logic image HOL-Main stops at theory Main, and thus facilitates
   231 experimentation due to shorter build times.
   232 
   233 * Logic image HOL-NSA contains theories of nonstandard analysis which
   234 were previously part of former HOL-Complex.  Entry point Hyperreal
   235 remains valid, but theories formerly using Complex_Main should now use
   236 new entry point Hypercomplex.
   237 
   238 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   239 Posix processes.  Avoids potentially expensive forking of the ML
   240 process.  New thread-based implementation also works on non-Unix
   241 platforms (Cygwin).  Provers are no longer hardwired, but defined
   242 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   243 commands are covered in the isar-ref manual.
   244 
   245 * Wrapper scripts for remote SystemOnTPTP service allows to use
   246 sledgehammer without local ATP installation (Vampire etc.). Other
   247 provers may be included via suitable ML wrappers, see also
   248 src/HOL/ATP_Linkup.thy.
   249 
   250 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   251 menu.
   252 
   253 * The metis method no longer fails because the theorem is too trivial
   254 (contains the empty clause).
   255 
   256 * The metis method now fails in the usual manner, rather than raising
   257 an exception, if it determines that it cannot prove the theorem.
   258 
   259 * Method "coherent" implements a prover for coherent logic (see also
   260 src/Tools/coherent.ML).
   261 
   262 * Constants "undefined" and "default" replace "arbitrary".  Usually
   263 "undefined" is the right choice to replace "arbitrary", though
   264 logically there is no difference.  INCOMPATIBILITY.
   265 
   266 * Command "value" now integrates different evaluation mechanisms.  The
   267 result of the first successful evaluation mechanism is printed.  In
   268 square brackets a particular named evaluation mechanisms may be
   269 specified (currently, [SML], [code] or [nbe]).  See further
   270 src/HOL/ex/Eval_Examples.thy.
   271 
   272 * Normalization by evaluation now allows non-leftlinear equations.
   273 Declare with attribute [code nbe].
   274 
   275 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   276 as the structured Isar versions "cases" and "induct", cf. the
   277 corresponding "cases" and "induct" attributes.  Mutual induction rules
   278 are now presented as a list of individual projections
   279 (e.g. foo_bar.inducts for types foo and bar); the old format with
   280 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   281 rare situations a different rule is selected --- notably nested tuple
   282 elimination instead of former prod.exhaust: use explicit (case_tac t
   283 rule: prod.exhaust) here.
   284 
   285 * Attributes "cases", "induct", "coinduct" support "del" option.
   286 
   287 * Removed fact "case_split_thm", which duplicates "case_split".
   288 
   289 * The option datatype has been moved to a new theory Option.  Renamed
   290 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   291 
   292 * New predicate "strict_mono" classifies strict functions on partial
   293 orders.  With strict functions on linear orders, reasoning about
   294 (in)equalities is facilitated by theorems "strict_mono_eq",
   295 "strict_mono_less_eq" and "strict_mono_less".
   296 
   297 * Some set operations are now proper qualified constants with
   298 authentic syntax.  INCOMPATIBILITY:
   299 
   300     op Int ~>   Set.Int
   301     op Un ~>    Set.Un
   302     INTER ~>    Set.INTER
   303     UNION ~>    Set.UNION
   304     Inter ~>    Set.Inter
   305     Union ~>    Set.Union
   306     {} ~>       Set.empty
   307     UNIV ~>     Set.UNIV
   308 
   309 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   310 theory Set.
   311 
   312 * Auxiliary class "itself" has disappeared -- classes without any
   313 parameter are treated as expected by the 'class' command.
   314 
   315 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   316 
   317 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   318 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   319 
   320 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   321 method "approximation".  It proves formulas on real values by using
   322 interval arithmetic.  In the formulas are also the transcendental
   323 functions sin, cos, tan, atan, ln, exp and the constant pi are
   324 allowed. For examples see
   325 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   326 
   327 * Theory "Reflection" now resides in HOL/Library.
   328 
   329 * Entry point to Word library now simply named "Word".
   330 INCOMPATIBILITY.
   331 
   332 * Made source layout more coherent with logical distribution
   333 structure:
   334 
   335     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   336     src/HOL/Library/Code_Message.thy ~> src/HOL/
   337     src/HOL/Library/GCD.thy ~> src/HOL/
   338     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   339     src/HOL/Library/Parity.thy ~> src/HOL/
   340     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   341     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   342     src/HOL/Real/Lubs.thy ~> src/HOL/
   343     src/HOL/Real/PReal.thy ~> src/HOL/
   344     src/HOL/Real/Rational.thy ~> src/HOL/
   345     src/HOL/Real/RComplete.thy ~> src/HOL/
   346     src/HOL/Real/RealDef.thy ~> src/HOL/
   347     src/HOL/Real/RealPow.thy ~> src/HOL/
   348     src/HOL/Real/Real.thy ~> src/HOL/
   349     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   350     src/HOL/Complex/Complex.thy ~> src/HOL/
   351     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   352     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   353     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   354     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   355     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   356     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   357     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   358     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   359     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   360     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   361     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   362     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   363     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   364     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   365     src/HOL/Real/Float ~> src/HOL/Library/
   366     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   367     src/HOL/Real/RealVector.thy ~> src/HOL/
   368 
   369     src/HOL/arith_data.ML ~> src/HOL/Tools
   370     src/HOL/hologic.ML ~> src/HOL/Tools
   371     src/HOL/simpdata.ML ~> src/HOL/Tools
   372     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   373     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   374     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   375     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   376     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   377     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   378     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   379 
   380     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   381     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   382     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   383     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   384     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   385     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   386 
   387 * If methods "eval" and "evaluation" encounter a structured proof
   388 state with !!/==>, only the conclusion is evaluated to True (if
   389 possible), avoiding strange error messages.
   390 
   391 * Method "sizechange" automates termination proofs using (a
   392 modification of) the size-change principle.  Requires SAT solver.  See
   393 src/HOL/ex/Termination.thy for examples.
   394 
   395 * Simplifier: simproc for let expressions now unfolds if bound
   396 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   397 
   398 * Method "arith": Linear arithmetic now ignores all inequalities when
   399 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   400 
   401 * New attribute "arith" for facts that should always be used
   402 automatically by arithmetic. It is intended to be used locally in
   403 proofs, e.g.
   404 
   405   assumes [arith]: "x > 0"
   406 
   407 Global usage is discouraged because of possible performance impact.
   408 
   409 * New classes "top" and "bot" with corresponding operations "top" and
   410 "bot" in theory Orderings; instantiation of class "complete_lattice"
   411 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   412 
   413 * Changed definition lemma "less_fun_def" in order to provide an
   414 instance for preorders on functions; use lemma "less_le" instead.
   415 INCOMPATIBILITY.
   416 
   417 * Theory Orderings: class "wellorder" moved here, with explicit
   418 induction rule "less_induct" as assumption.  For instantiation of
   419 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   420 INCOMPATIBILITY.
   421 
   422 * Theory Orderings: added class "preorder" as superclass of "order".
   423 INCOMPATIBILITY: Instantiation proofs for order, linorder
   424 etc. slightly changed.  Some theorems named order_class.* now named
   425 preorder_class.*.
   426 
   427 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   428 "diag" to "Id_on".
   429 
   430 * Theory Finite_Set: added a new fold combinator of type
   431 
   432   ('a => 'b => 'b) => 'b => 'a set => 'b
   433 
   434 Occasionally this is more convenient than the old fold combinator
   435 which is now defined in terms of the new one and renamed to
   436 fold_image.
   437 
   438 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   439 and "ring_simps" have been replaced by "algebra_simps" (which can be
   440 extended with further lemmas!).  At the moment both still exist but
   441 the former will disappear at some point.
   442 
   443 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   444 class recpower.  Type-specific simp rules for various recpower types
   445 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   446 
   447 rat_power_0    -> power_0
   448 rat_power_Suc  -> power_Suc
   449 realpow_0      -> power_0
   450 realpow_Suc    -> power_Suc
   451 complexpow_0   -> power_0
   452 complexpow_Suc -> power_Suc
   453 power_poly_0   -> power_0
   454 power_poly_Suc -> power_Suc
   455 
   456 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   457 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   458 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   459 of lemmas from Divides has been generalized from nat to class
   460 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   461 renames resulting from duplicate elimination:
   462 
   463     dvd_def_mod ~>          dvd_eq_mod_eq_0
   464     zero_dvd_iff ~>         dvd_0_left_iff
   465     dvd_0 ~>                dvd_0_right
   466     DIVISION_BY_ZERO_DIV ~> div_by_0
   467     DIVISION_BY_ZERO_MOD ~> mod_by_0
   468     mult_div ~>             div_mult_self2_is_id
   469     mult_mod ~>             mod_mult_self2_is_0
   470 
   471 * Theory IntDiv: removed many lemmas that are instances of class-based
   472 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   473 rename old lemmas as follows:
   474 
   475 dvd_diff               -> nat_dvd_diff
   476 dvd_zminus_iff         -> dvd_minus_iff
   477 mod_add1_eq            -> mod_add_eq
   478 mod_mult1_eq           -> mod_mult_right_eq
   479 mod_mult1_eq'          -> mod_mult_left_eq
   480 mod_mult_distrib_mod   -> mod_mult_eq
   481 nat_mod_add_left_eq    -> mod_add_left_eq
   482 nat_mod_add_right_eq   -> mod_add_right_eq
   483 nat_mod_div_trivial    -> mod_div_trivial
   484 nat_mod_mod_trivial    -> mod_mod_trivial
   485 zdiv_zadd_self1        -> div_add_self1
   486 zdiv_zadd_self2        -> div_add_self2
   487 zdiv_zmult_self1       -> div_mult_self2_is_id
   488 zdiv_zmult_self2       -> div_mult_self1_is_id
   489 zdvd_triv_left         -> dvd_triv_left
   490 zdvd_triv_right        -> dvd_triv_right
   491 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   492 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   493 zmod_zadd_left_eq      -> mod_add_left_eq
   494 zmod_zadd_right_eq     -> mod_add_right_eq
   495 zmod_zadd_self1        -> mod_add_self1
   496 zmod_zadd_self2        -> mod_add_self2
   497 zmod_zadd1_eq          -> mod_add_eq
   498 zmod_zdiff1_eq         -> mod_diff_eq
   499 zmod_zdvd_zmod         -> mod_mod_cancel
   500 zmod_zmod_cancel       -> mod_mod_cancel
   501 zmod_zmult_self1       -> mod_mult_self2_is_0
   502 zmod_zmult_self2       -> mod_mult_self1_is_0
   503 zmod_1                 -> mod_by_1
   504 zdiv_1                 -> div_by_1
   505 zdvd_abs1              -> abs_dvd_iff
   506 zdvd_abs2              -> dvd_abs_iff
   507 zdvd_refl              -> dvd_refl
   508 zdvd_trans             -> dvd_trans
   509 zdvd_zadd              -> dvd_add
   510 zdvd_zdiff             -> dvd_diff
   511 zdvd_zminus_iff        -> dvd_minus_iff
   512 zdvd_zminus2_iff       -> minus_dvd_iff
   513 zdvd_zmultD            -> dvd_mult_right
   514 zdvd_zmultD2           -> dvd_mult_left
   515 zdvd_zmult_mono        -> mult_dvd_mono
   516 zdvd_0_right           -> dvd_0_right
   517 zdvd_0_left            -> dvd_0_left_iff
   518 zdvd_1_left            -> one_dvd
   519 zminus_dvd_iff         -> minus_dvd_iff
   520 
   521 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   522 
   523 * The real numbers offer decimal input syntax: 12.34 is translated
   524 into 1234/10^2. This translation is not reversed upon output.
   525 
   526 * Theory Library/Polynomial defines an abstract type 'a poly of
   527 univariate polynomials with coefficients of type 'a.  In addition to
   528 the standard ring operations, it also supports div and mod.  Code
   529 generation is also supported, using list-style constructors.
   530 
   531 * Theory Library/Inner_Product defines a class of real_inner for real
   532 inner product spaces, with an overloaded operation inner :: 'a => 'a
   533 => real.  Class real_inner is a subclass of real_normed_vector from
   534 theory RealVector.
   535 
   536 * Theory Library/Product_Vector provides instances for the product
   537 type 'a * 'b of several classes from RealVector and Inner_Product.
   538 Definitions of addition, subtraction, scalar multiplication, norms,
   539 and inner products are included.
   540 
   541 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   542 addition to the field operations, numerals and case syntax are also
   543 supported.
   544 
   545 * Theory Library/Diagonalize provides constructive version of Cantor's
   546 first diagonalization argument.
   547 
   548 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   549 zlcm (for int); carried together from various gcd/lcm developements in
   550 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   551 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   552 may recover tupled syntax as follows:
   553 
   554     hide (open) const gcd
   555     abbreviation gcd where
   556       "gcd == (%(a, b). GCD.gcd a b)"
   557     notation (output)
   558       GCD.gcd ("gcd '(_, _')")
   559 
   560 The same works for lcm, zgcd, zlcm.
   561 
   562 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   563 instantiations for algebraic structures.  Removed some duplicate
   564 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   565 
   566 * ML antiquotation @{code} takes a constant as argument and generates
   567 corresponding code in background and inserts name of the corresponding
   568 resulting ML value/function/datatype constructor binding in place.
   569 All occurrences of @{code} with a single ML block are generated
   570 simultaneously.  Provides a generic and safe interface for
   571 instrumentalizing code generation.  See
   572 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   573 In future you ought to refrain from ad-hoc compiling generated SML
   574 code on the ML toplevel.  Note that (for technical reasons) @{code}
   575 cannot refer to constants for which user-defined serializations are
   576 set.  Refer to the corresponding ML counterpart directly in that
   577 cases.
   578 
   579 * Command 'rep_datatype': instead of theorem names the command now
   580 takes a list of terms denoting the constructors of the type to be
   581 represented as datatype.  The characteristic theorems have to be
   582 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   583 have disappeared in favour of existing ones:
   584 
   585     unit_induct                 ~> unit.induct
   586     prod_induct                 ~> prod.induct
   587     sum_induct                  ~> sum.induct
   588     Suc_Suc_eq                  ~> nat.inject
   589     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   590 
   591 
   592 *** HOL-Algebra ***
   593 
   594 * New locales for orders and lattices where the equivalence relation
   595 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   596 locales use a record structure with field eq for the equivalence.
   597 
   598 * New theory of factorial domains.
   599 
   600 * Units_l_inv and Units_r_inv are now simp rules by default.
   601 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   602 and/or r_inv will now also require deletion of these lemmas.
   603 
   604 * Renamed the following theorems, INCOMPATIBILITY:
   605 
   606 UpperD ~> Upper_memD
   607 LowerD ~> Lower_memD
   608 least_carrier ~> least_closed
   609 greatest_carrier ~> greatest_closed
   610 greatest_Lower_above ~> greatest_Lower_below
   611 one_zero ~> carrier_one_zero
   612 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   613 
   614 
   615 *** HOLCF ***
   616 
   617 * Reimplemented the simplification procedure for proving continuity
   618 subgoals.  The new simproc is extensible; users can declare additional
   619 continuity introduction rules with the attribute [cont2cont].
   620 
   621 * The continuity simproc now uses a different introduction rule for
   622 solving continuity subgoals on terms with lambda abstractions.  In
   623 some rare cases the new simproc may fail to solve subgoals that the
   624 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   625 Potential INCOMPATIBILITY.
   626 
   627 * The syntax of the fixrec package now conforms to the general
   628 specification format of inductive, primrec, function, etc.  See
   629 src/HOLCF/ex/Fixrec_ex.thy for examples.  INCOMPATIBILITY.
   630 
   631 
   632 *** ZF ***
   633 
   634 * Proof of Zorn's Lemma for partial orders.
   635 
   636 
   637 *** ML ***
   638 
   639 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   640 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   641 depends on multithreading, so timouts will not work before Poly/ML
   642 5.2.1!
   643 
   644 * High-level support for concurrent ML programming, see
   645 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   646 particularly convenient to organize independent functional
   647 computations.  The concept of "synchronized variables" provides a
   648 higher-order interface for components with shared state, avoiding the
   649 delicate details of mutexes and condition variables.  (Requires
   650 Poly/ML 5.2.1 or later.)
   651 
   652 * ML bindings produced via Isar commands are stored within the Isar
   653 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   654 become thread-safe and work with undo as expected (concerning
   655 top-level bindings, not side-effects on global references).
   656 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   657 compiler at runtime; really global bindings need to be given outside a
   658 theory.  (Requires Poly/ML 5.2 or later.)
   659 
   660 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   661 context.  Top-level ML bindings are stored within the proof context in
   662 a purely sequential fashion, disregarding the nested proof structure.
   663 ML bindings introduced by 'ML_prf' are discarded at the end of the
   664 proof.  (Requires Poly/ML 5.2 or later.)
   665 
   666 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   667 and Method.setup, as well as Isar commands 'attribute_setup' and
   668 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   669 existing code accordingly, or use plain 'setup' together with old
   670 Method.add_method.
   671 
   672 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   673 to 'a -> thm, while results are always tagged with an authentic oracle
   674 name.  The Isar command 'oracle' is now polymorphic, no argument type
   675 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   676 accordingly.  Note that extra performance may be gained by producing
   677 the cterm carefully, avoiding slow Thm.cterm_of.
   678 
   679 * Simplified interface for defining document antiquotations via
   680 ThyOutput.antiquotation, ThyOutput.output, and optionally
   681 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   682 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   683 examples.
   684 
   685 * More systematic treatment of long names, abstract name bindings, and
   686 name space operations.  Basic operations on qualified names have been
   687 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   688 Long_Name.append.  Old type bstring has been mostly replaced by
   689 abstract type binding (see structure Binding), which supports precise
   690 qualification by packages and local theory targets, as well as proper
   691 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   692 bstring values into Binding.name, or better pass through abstract
   693 bindings everywhere.  See further src/Pure/General/long_name.ML,
   694 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   695 
   696 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   697 LocalTheory.note etc.) now refer to the *full* internal name, not the
   698 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   699 
   700 * Disposed old type and term read functions (Sign.read_def_typ,
   701 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   702 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   703 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   704 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   705 resort for legacy applications.
   706 
   707 * Disposed old declarations, tactics, tactic combinators that refer to
   708 the simpset or claset of an implicit theory (such as Addsimps,
   709 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   710 embedded ML text, or local_simpset_of with a proper context passed as
   711 explicit runtime argument.
   712 
   713 * Rules and tactics that read instantiations (read_instantiate,
   714 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   715 context, which is required for parsing and type-checking.  Moreover,
   716 the variables are specified as plain indexnames, not string encodings
   717 thereof.  INCOMPATIBILITY.
   718 
   719 * Generic Toplevel.add_hook interface allows to analyze the result of
   720 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   721 for theorem dependency output of transactions resulting in a new
   722 theory state.
   723 
   724 * ML antiquotations: block-structured compilation context indicated by
   725 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   726 
   727   @{binding name}                         - basic name binding
   728   @{let ?pat = term}                      - term abbreviation (HO matching)
   729   @{note name = fact}                     - fact abbreviation
   730   @{thm fact}                             - singleton fact (with attributes)
   731   @{thms fact}                            - general fact (with attributes)
   732   @{lemma prop by method}                 - singleton goal
   733   @{lemma prop by meth1 meth2}            - singleton goal
   734   @{lemma prop1 ... propN by method}      - general goal
   735   @{lemma prop1 ... propN by meth1 meth2} - general goal
   736   @{lemma (open) ...}                     - open derivation
   737 
   738 
   739 *** System ***
   740 
   741 * The Isabelle "emacs" tool provides a specific interface to invoke
   742 Proof General / Emacs, with more explicit failure if that is not
   743 installed (the old isabelle-interface script silently falls back on
   744 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   745 installation location of the Proof General distribution.
   746 
   747 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   748 the Isabelle process into a JVM/Scala application.  See
   749 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   750 process wrapper has been discontinued.)
   751 
   752 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   753 
   754 * Various status messages (with exact source position information) are
   755 emitted, if proper markup print mode is enabled.  This allows
   756 user-interface components to provide detailed feedback on internal
   757 prover operations.
   758 
   759 
   760 
   761 New in Isabelle2008 (June 2008)
   762 -------------------------------
   763 
   764 *** General ***
   765 
   766 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   767 and updated, with formally checked references as hyperlinks.
   768 
   769 * Theory loader: use_thy (and similar operations) no longer set the
   770 implicit ML context, which was occasionally hard to predict and in
   771 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   772 provides a proper context already.
   773 
   774 * Theory loader: old-style ML proof scripts being *attached* to a thy
   775 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   776 'use' within a theory file will do the job.
   777 
   778 * Name space merge now observes canonical order, i.e. the second space
   779 is inserted into the first one, while existing entries in the first
   780 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   781 swap theory imports.
   782 
   783 * Syntax: symbol \<chi> is now considered a letter.  Potential
   784 INCOMPATIBILITY in identifier syntax etc.
   785 
   786 * Outer syntax: string tokens no longer admit escaped white space,
   787 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   788 white space without escapes.
   789 
   790 * Outer syntax: string tokens may contain arbitrary character codes
   791 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   792 "foo_bar".
   793 
   794 
   795 *** Pure ***
   796 
   797 * Context-dependent token translations.  Default setup reverts locally
   798 fixed variables, and adds hilite markup for undeclared frees.
   799 
   800 * Unused theorems can be found using the new command 'unused_thms'.
   801 There are three ways of invoking it:
   802 
   803 (1) unused_thms
   804      Only finds unused theorems in the current theory.
   805 
   806 (2) unused_thms thy_1 ... thy_n -
   807      Finds unused theorems in the current theory and all of its ancestors,
   808      excluding the theories thy_1 ... thy_n and all of their ancestors.
   809 
   810 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   811      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   812      their ancestors, excluding the theories thy_1 ... thy_n and all of
   813      their ancestors.
   814 
   815 In order to increase the readability of the list produced by
   816 unused_thms, theorems that have been created by a particular instance
   817 of a theory command such as 'inductive' or 'function' are considered
   818 to belong to the same "group", meaning that if at least one theorem in
   819 this group is used, the other theorems in the same group are no longer
   820 reported as unused.  Moreover, if all theorems in the group are
   821 unused, only one theorem in the group is displayed.
   822 
   823 Note that proof objects have to be switched on in order for
   824 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   825 usually the case when using Proof General with the default settings).
   826 
   827 * Authentic naming of facts disallows ad-hoc overwriting of previous
   828 theorems within the same name space.  INCOMPATIBILITY, need to remove
   829 duplicate fact bindings, or even accidental fact duplications.  Note
   830 that tools may maintain dynamically scoped facts systematically, using
   831 PureThy.add_thms_dynamic.
   832 
   833 * Command 'hide' now allows to hide from "fact" name space as well.
   834 
   835 * Eliminated destructive theorem database, simpset, claset, and
   836 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   837 update of theories within ML code.
   838 
   839 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   840 INCOMPATIBILITY, object-logics depending on former Pure require
   841 additional setup PureThy.old_appl_syntax_setup; object-logics
   842 depending on former CPure need to refer to Pure.
   843 
   844 * Commands 'use' and 'ML' are now purely functional, operating on
   845 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
   846 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
   847 INCOMPATIBILITY.
   848 
   849 * Command 'setup': discontinued implicit version with ML reference.
   850 
   851 * Instantiation target allows for simultaneous specification of class
   852 instance operations together with an instantiation proof.
   853 Type-checking phase allows to refer to class operations uniformly.
   854 See src/HOL/Complex/Complex.thy for an Isar example and
   855 src/HOL/Library/Eval.thy for an ML example.
   856 
   857 * Indexing of literal facts: be more serious about including only
   858 facts from the visible specification/proof context, but not the
   859 background context (locale etc.).  Affects `prop` notation and method
   860 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
   861 situations.
   862 
   863 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   864 "(open)" option, which used to expose internal bound variables to the
   865 proof text.
   866 
   867 * Isar statements: removed obsolete case "rule_context".
   868 INCOMPATIBILITY, better use explicit fixes/assumes.
   869 
   870 * Locale proofs: default proof step now includes 'unfold_locales';
   871 hence 'proof' without argument may be used to unfold locale
   872 predicates.
   873 
   874 
   875 *** Document preparation ***
   876 
   877 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   878 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   879 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   880 spot); renamed link color from "darkblue" to "linkcolor" (default
   881 value unchanged, can be redefined via \definecolor); no longer sets
   882 "a4paper" option (unnecessary or even intrusive).
   883 
   884 * Antiquotation @{lemma A method} proves proposition A by the given
   885 method (either a method name or a method name plus (optional) method
   886 arguments in parentheses) and prints A just like @{prop A}.
   887 
   888 
   889 *** HOL ***
   890 
   891 * New primrec package.  Specification syntax conforms in style to
   892 definition/function/....  No separate induction rule is provided.  The
   893 "primrec" command distinguishes old-style and new-style specifications
   894 by syntax.  The former primrec package is now named OldPrimrecPackage.
   895 When adjusting theories, beware: constants stemming from new-style
   896 primrec specifications have authentic syntax.
   897 
   898 * Metis prover is now an order of magnitude faster, and also works
   899 with multithreading.
   900 
   901 * Metis: the maximum number of clauses that can be produced from a
   902 theorem is now given by the attribute max_clauses.  Theorems that
   903 exceed this number are ignored, with a warning printed.
   904 
   905 * Sledgehammer no longer produces structured proofs by default. To
   906 enable, declare [[sledgehammer_full = true]].  Attributes
   907 reconstruction_modulus, reconstruction_sorts renamed
   908 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   909 
   910 * Method "induct_scheme" derives user-specified induction rules
   911 from well-founded induction and completeness of patterns. This factors
   912 out some operations that are done internally by the function package
   913 and makes them available separately.  See
   914 src/HOL/ex/Induction_Scheme.thy for examples.
   915 
   916 * More flexible generation of measure functions for termination
   917 proofs: Measure functions can be declared by proving a rule of the
   918 form "is_measure f" and giving it the [measure_function] attribute.
   919 The "is_measure" predicate is logically meaningless (always true), and
   920 just guides the heuristic.  To find suitable measure functions, the
   921 termination prover sets up the goal "is_measure ?f" of the appropriate
   922 type and generates all solutions by prolog-style backwards proof using
   923 the declared rules.
   924 
   925 This setup also deals with rules like 
   926 
   927   "is_measure f ==> is_measure (list_size f)"
   928 
   929 which accommodates nested datatypes that recurse through lists.
   930 Similar rules are predeclared for products and option types.
   931 
   932 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
   933 
   934   INCOMPATIBILITIES:
   935 
   936   - Definitions of overloaded constants on sets have to be replaced by
   937     definitions on => and bool.
   938 
   939   - Some definitions of overloaded operators on sets can now be proved
   940     using the definitions of the operators on => and bool.  Therefore,
   941     the following theorems have been renamed:
   942 
   943       subset_def   -> subset_eq
   944       psubset_def  -> psubset_eq
   945       set_diff_def -> set_diff_eq
   946       Compl_def    -> Compl_eq
   947       Sup_set_def  -> Sup_set_eq
   948       Inf_set_def  -> Inf_set_eq
   949       sup_set_def  -> sup_set_eq
   950       inf_set_def  -> inf_set_eq
   951 
   952   - Due to the incompleteness of the HO unification algorithm, some
   953     rules such as subst may require manual instantiation, if some of
   954     the unknowns in the rule is a set.
   955 
   956   - Higher order unification and forward proofs:
   957     The proof pattern
   958 
   959       have "P (S::'a set)" <...>
   960       then have "EX S. P S" ..
   961 
   962     no longer works (due to the incompleteness of the HO unification
   963     algorithm) and must be replaced by the pattern
   964 
   965       have "EX S. P S"
   966       proof
   967         show "P S" <...>
   968       qed
   969 
   970   - Calculational reasoning with subst (or similar rules):
   971     The proof pattern
   972 
   973       have "P (S::'a set)" <...>
   974       also have "S = T" <...>
   975       finally have "P T" .
   976 
   977     no longer works (for similar reasons as the previous example) and
   978     must be replaced by something like
   979 
   980       have "P (S::'a set)" <...>
   981       moreover have "S = T" <...>
   982       ultimately have "P T" by simp
   983 
   984   - Tactics or packages written in ML code:
   985     Code performing pattern matching on types via
   986 
   987       Type ("set", [T]) => ...
   988 
   989     must be rewritten. Moreover, functions like strip_type or
   990     binder_types no longer return the right value when applied to a
   991     type of the form
   992 
   993       T1 => ... => Tn => U => bool
   994 
   995     rather than
   996 
   997       T1 => ... => Tn => U set
   998 
   999 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1000 Wellfounded_Relations to theory Wellfounded.
  1001 
  1002 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1003 
  1004 * Class finite no longer treats UNIV as class parameter.  Use class
  1005 enum from theory Library/Enum instead to achieve a similar effect.
  1006 INCOMPATIBILITY.
  1007 
  1008 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1009 and "Cons".  INCOMPATIBILITY.
  1010 
  1011 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1012 Potential INCOMPATIBILITY.
  1013 
  1014 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1015 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1016 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1017 
  1018 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1019 the same name in theory Orderings:
  1020 
  1021   less_trans
  1022   less_linear
  1023   le_imp_less_or_eq
  1024   le_less_trans
  1025   less_le_trans
  1026   less_not_sym
  1027   less_asym
  1028 
  1029 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1030 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1031 and different variable names.
  1032 
  1033 * Library/Option_ord.thy: Canonical order on option type.
  1034 
  1035 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1036 finite maps.
  1037 
  1038 * Library/Countable.thy: Type class for countable types.
  1039 
  1040 * Theory Int: The representation of numerals has changed.  The infix
  1041 operator BIT and the bit datatype with constructors B0 and B1 have
  1042 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1043 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1044 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1045 accordingly.
  1046 
  1047 * Theory Nat: definition of <= and < on natural numbers no longer
  1048 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1049 le_def and less_def have disappeared.  Consider lemmas not_less
  1050 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1051 
  1052 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1053 (whose purpose mainly is for various fold_set functionals) have been
  1054 abandoned in favor of the existing algebraic classes
  1055 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1056 lower_semilattice (resp. upper_semilattice) and linorder.
  1057 INCOMPATIBILITY.
  1058 
  1059 * Theory Transitive_Closure: induct and cases rules now declare proper
  1060 case_names ("base" and "step").  INCOMPATIBILITY.
  1061 
  1062 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1063 lattices.  The form set-specific version is available as
  1064 Inductive.lfp_ordinal_induct_set.
  1065 
  1066 * Renamed theorems "power.simps" to "power_int.simps".
  1067 INCOMPATIBILITY.
  1068 
  1069 * Class semiring_div provides basic abstract properties of semirings
  1070 with division and modulo operations.  Subsumes former class dvd_mod.
  1071 
  1072 * Merged theories IntDef, Numeral and IntArith into unified theory
  1073 Int.  INCOMPATIBILITY.
  1074 
  1075 * Theory Library/Code_Index: type "index" now represents natural
  1076 numbers rather than integers.  INCOMPATIBILITY.
  1077 
  1078 * New class "uminus" with operation "uminus" (split of from class
  1079 "minus" which now only has operation "minus", binary).
  1080 INCOMPATIBILITY.
  1081 
  1082 * Constants "card", "internal_split", "option_map" now with authentic
  1083 syntax.  INCOMPATIBILITY.
  1084 
  1085 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1086 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1087 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1088 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1089 Sup_set_def, le_def, less_def, option_map_def now with object
  1090 equality.  INCOMPATIBILITY.
  1091 
  1092 * Records. Removed K_record, and replaced it by pure lambda term
  1093 %x. c. The simplifier setup is now more robust against eta expansion.
  1094 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1095 
  1096 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1097 
  1098 * Library/ListVector: new theory of arithmetic vector operations.
  1099 
  1100 * Library/Order_Relation: new theory of various orderings as sets of
  1101 pairs.  Defines preorders, partial orders, linear orders and
  1102 well-orders on sets and on types.
  1103 
  1104 
  1105 *** ZF ***
  1106 
  1107 * Renamed some theories to allow to loading both ZF and HOL in the
  1108 same session:
  1109 
  1110   Datatype  -> Datatype_ZF
  1111   Inductive -> Inductive_ZF
  1112   Int       -> Int_ZF
  1113   IntDiv    -> IntDiv_ZF
  1114   Nat       -> Nat_ZF
  1115   List      -> List_ZF
  1116   Main      -> Main_ZF
  1117 
  1118 INCOMPATIBILITY: ZF theories that import individual theories below
  1119 Main might need to be adapted.  Regular theory Main is still
  1120 available, as trivial extension of Main_ZF.
  1121 
  1122 
  1123 *** ML ***
  1124 
  1125 * ML within Isar: antiquotation @{const name} or @{const
  1126 name(typargs)} produces statically-checked Const term.
  1127 
  1128 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1129 (of the same name).  Removed obsolete print command.
  1130 
  1131 * Removed obsolete "use_legacy_bindings" function.
  1132 
  1133 * The ``print mode'' is now a thread-local value derived from a global
  1134 template (the former print_mode reference), thus access becomes
  1135 non-critical.  The global print_mode reference is for session
  1136 management only; user-code should use print_mode_value,
  1137 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1138 
  1139 * Functions system/system_out provide a robust way to invoke external
  1140 shell commands, with propagation of interrupts (requires Poly/ML
  1141 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1142 
  1143 
  1144 *** System ***
  1145 
  1146 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1147 in accordance with Proof General 3.7, which prefers GNU emacs.
  1148 
  1149 * isatool tty runs Isabelle process with plain tty interaction;
  1150 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1151 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1152 
  1153 * isatool browser now works with Cygwin as well, using general
  1154 "javapath" function defined in Isabelle process environment.
  1155 
  1156 * YXML notation provides a simple and efficient alternative to
  1157 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1158 isatool yxml as described in the Isabelle system manual.
  1159 
  1160 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1161 provides general wrapper for managing an Isabelle process in a robust
  1162 fashion, with ``cooked'' output from stdin/stderr.
  1163 
  1164 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1165 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1166 
  1167 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1168 way of changing the user's settings is via
  1169 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1170 script.
  1171 
  1172 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1173 cores of the underlying machine, which is a good starting point for
  1174 optimal performance tuning.  The corresponding usedir option -M allows
  1175 "max" as an alias for "0".  WARNING: does not work on certain versions
  1176 of Mac OS (with Poly/ML 5.1).
  1177 
  1178 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1179 adverse effect of Isabelle flooding interactive front-ends (notably
  1180 ProofGeneral / XEmacs).
  1181 
  1182 
  1183 
  1184 New in Isabelle2007 (November 2007)
  1185 -----------------------------------
  1186 
  1187 *** General ***
  1188 
  1189 * More uniform information about legacy features, notably a
  1190 warning/error of "Legacy feature: ...", depending on the state of the
  1191 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1192 legacy features will disappear eventually.
  1193 
  1194 * Theory syntax: the header format ``theory A = B + C:'' has been
  1195 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1196 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1197 
  1198 * Theory syntax: the old non-Isar theory file format has been
  1199 discontinued altogether.  Note that ML proof scripts may still be used
  1200 with Isar theories; migration is usually quite simple with the ML
  1201 function use_legacy_bindings.  INCOMPATIBILITY.
  1202 
  1203 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1204 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1205 quotes.
  1206 
  1207 * Theory loader: be more serious about observing the static theory
  1208 header specifications (including optional directories), but not the
  1209 accidental file locations of previously successful loads.  The strict
  1210 update policy of former update_thy is now already performed by
  1211 use_thy, so the former has been removed; use_thys updates several
  1212 theories simultaneously, just as 'imports' within a theory header
  1213 specification, but without merging the results.  Potential
  1214 INCOMPATIBILITY: may need to refine theory headers and commands
  1215 ROOT.ML which depend on load order.
  1216 
  1217 * Theory loader: optional support for content-based file
  1218 identification, instead of the traditional scheme of full physical
  1219 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1220 (cf. the system manual).  The new scheme allows to work with
  1221 non-finished theories in persistent session images, such that source
  1222 files may be moved later on without requiring reloads.
  1223 
  1224 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1225 file (with the same base name as the theory) are considered a legacy
  1226 feature, which will disappear eventually. Even now, the theory loader
  1227 no longer maintains dependencies on such files.
  1228 
  1229 * Syntax: the scope for resolving ambiguities via type-inference is
  1230 now limited to individual terms, instead of whole simultaneous
  1231 specifications as before. This greatly reduces the complexity of the
  1232 syntax module and improves flexibility by separating parsing and
  1233 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1234 'fixes' etc.) are required in rare situations.
  1235 
  1236 * Syntax: constants introduced by new-style packages ('definition',
  1237 'abbreviation' etc.) are passed through the syntax module in
  1238 ``authentic mode''. This means that associated mixfix annotations
  1239 really stick to such constants, independently of potential name space
  1240 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1241 trees are represented slightly differently, may need to adapt syntax
  1242 translations accordingly. Use CONST marker in 'translations' and
  1243 @{const_syntax} antiquotation in 'parse_translation' etc.
  1244 
  1245 * Legacy goal package: reduced interface to the bare minimum required
  1246 to keep existing proof scripts running.  Most other user-level
  1247 functions are now part of the OldGoals structure, which is *not* open
  1248 by default (consider isatool expandshort before open OldGoals).
  1249 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1250 these tend to cause confusion about the actual goal (!) context being
  1251 used here, which is not necessarily the same as the_context().
  1252 
  1253 * Command 'find_theorems': supports "*" wild-card in "name:"
  1254 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1255 support a specific search form (see ProofGeneral/CHANGES).
  1256 
  1257 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1258 by default, which means that "prems" (and also "fixed variables") are
  1259 suppressed from proof state output.  Note that the ProofGeneral
  1260 settings mechanism allows to change and save options persistently, but
  1261 older versions of Isabelle will fail to start up if a negative prems
  1262 limit is imposed.
  1263 
  1264 * Local theory targets may be specified by non-nested blocks of
  1265 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1266 contain definitions, theorems etc., including any derived mechanism
  1267 that has been implemented on top of these primitives.  This concept
  1268 generalizes the existing ``theorem (in ...)'' towards more versatility
  1269 and scalability.
  1270 
  1271 * Proof General interface: proper undo of final 'end' command;
  1272 discontinued Isabelle/classic mode (ML proof scripts).
  1273 
  1274 
  1275 *** Document preparation ***
  1276 
  1277 * Added antiquotation @{theory name} which prints the given name,
  1278 after checking that it refers to a valid ancestor theory in the
  1279 current context.
  1280 
  1281 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1282 check the given source text as ML type/structure, printing verbatim.
  1283 
  1284 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1285 "c args == rhs" given in the current context.  (Any number of
  1286 arguments may be given on the LHS.)
  1287 
  1288 
  1289 *** Pure ***
  1290 
  1291 * The 'class' package offers a combination of axclass and locale to
  1292 achieve Haskell-like type classes in Isabelle.  Definitions and
  1293 theorems within a class context produce both relative results (with
  1294 implicit parameters according to the locale context), and polymorphic
  1295 constants with qualified polymorphism (according to the class
  1296 context).  Within the body context of a 'class' target, a separate
  1297 syntax layer ("user space type system") takes care of converting
  1298 between global polymorphic consts and internal locale representation.
  1299 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1300 "isatool doc classes" provides a tutorial.
  1301 
  1302 * Generic code generator framework allows to generate executable
  1303 code for ML and Haskell (including Isabelle classes).  A short usage
  1304 sketch:
  1305 
  1306     internal compilation:
  1307         export_code <list of constants (term syntax)> in SML
  1308     writing SML code to a file:
  1309         export_code <list of constants (term syntax)> in SML <filename>
  1310     writing OCaml code to a file:
  1311         export_code <list of constants (term syntax)> in OCaml <filename>
  1312     writing Haskell code to a bunch of files:
  1313         export_code <list of constants (term syntax)> in Haskell <filename>
  1314 
  1315     evaluating closed propositions to True/False using code generation:
  1316         method ``eval''
  1317 
  1318 Reasonable default setup of framework in HOL.
  1319 
  1320 Theorem attributs for selecting and transforming function equations theorems:
  1321 
  1322     [code fun]:        select a theorem as function equation for a specific constant
  1323     [code fun del]:    deselect a theorem as function equation for a specific constant
  1324     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1325     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1326 
  1327 User-defined serializations (target in {SML, OCaml, Haskell}):
  1328 
  1329     code_const <and-list of constants (term syntax)>
  1330       {(target) <and-list of const target syntax>}+
  1331 
  1332     code_type <and-list of type constructors>
  1333       {(target) <and-list of type target syntax>}+
  1334 
  1335     code_instance <and-list of instances>
  1336       {(target)}+
  1337         where instance ::= <type constructor> :: <class>
  1338 
  1339     code_class <and_list of classes>
  1340       {(target) <and-list of class target syntax>}+
  1341         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1342 
  1343 code_instance and code_class only are effective to target Haskell.
  1344 
  1345 For example usage see src/HOL/ex/Codegenerator.thy and
  1346 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1347 generation from Isabelle/HOL theories is available via "isatool doc
  1348 codegen".
  1349 
  1350 * Code generator: consts in 'consts_code' Isar commands are now
  1351 referred to by usual term syntax (including optional type
  1352 annotations).
  1353 
  1354 * Command 'no_translations' removes translation rules from theory
  1355 syntax.
  1356 
  1357 * Overloaded definitions are now actually checked for acyclic
  1358 dependencies.  The overloading scheme is slightly more general than
  1359 that of Haskell98, although Isabelle does not demand an exact
  1360 correspondence to type class and instance declarations.
  1361 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1362 exotic versions of overloading -- at the discretion of the user!
  1363 
  1364 Polymorphic constants are represented via type arguments, i.e. the
  1365 instantiation that matches an instance against the most general
  1366 declaration given in the signature.  For example, with the declaration
  1367 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1368 as c(nat).  Overloading is essentially simultaneous structural
  1369 recursion over such type arguments.  Incomplete specification patterns
  1370 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1371 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1372 Command 'print_theory' outputs the normalized system of recursive
  1373 equations, see section "definitions".
  1374 
  1375 * Configuration options are maintained within the theory or proof
  1376 context (with name and type bool/int/string), providing a very simple
  1377 interface to a poor-man's version of general context data.  Tools may
  1378 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1379 these values using Config.get etc.  Users may change options via an
  1380 associated attribute of the same name.  This form of context
  1381 declaration works particularly well with commands 'declare' or
  1382 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1383 very easy to avoid global references, which would not observe Isar
  1384 toplevel undo/redo and fail to work with multithreading.
  1385 
  1386 Various global ML references of Pure and HOL have been turned into
  1387 configuration options:
  1388 
  1389   Unify.search_bound		unify_search_bound
  1390   Unify.trace_bound		unify_trace_bound
  1391   Unify.trace_simp		unify_trace_simp
  1392   Unify.trace_types		unify_trace_types
  1393   Simplifier.simp_depth_limit	simp_depth_limit
  1394   Blast.depth_limit		blast_depth_limit
  1395   DatatypeProp.dtK		datatype_distinctness_limit
  1396   fast_arith_neq_limit  	fast_arith_neq_limit
  1397   fast_arith_split_limit	fast_arith_split_limit
  1398 
  1399 * Named collections of theorems may be easily installed as context
  1400 data using the functor NamedThmsFun (see also
  1401 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1402 attributes; there is also a toplevel print command.  This facility is
  1403 just a common case of general context data, which is the preferred way
  1404 for anything more complex than just a list of facts in canonical
  1405 order.
  1406 
  1407 * Isar: command 'declaration' augments a local theory by generic
  1408 declaration functions written in ML.  This enables arbitrary content
  1409 being added to the context, depending on a morphism that tells the
  1410 difference of the original declaration context wrt. the application
  1411 context encountered later on.
  1412 
  1413 * Isar: proper interfaces for simplification procedures.  Command
  1414 'simproc_setup' declares named simprocs (with match patterns, and body
  1415 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1416 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1417 
  1418 * Isar: an extra pair of brackets around attribute declarations
  1419 abbreviates a theorem reference involving an internal dummy fact,
  1420 which will be ignored later --- only the effect of the attribute on
  1421 the background context will persist.  This form of in-place
  1422 declarations is particularly useful with commands like 'declare' and
  1423 'using', for example ``have A using [[simproc a]] by simp''.
  1424 
  1425 * Isar: method "assumption" (and implicit closing of subproofs) now
  1426 takes simple non-atomic goal assumptions into account: after applying
  1427 an assumption as a rule the resulting subgoals are solved by atomic
  1428 assumption steps.  This is particularly useful to finish 'obtain'
  1429 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1430 without referring to the original premise "!!x. P x ==> thesis" in the
  1431 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1432 more permissive.
  1433 
  1434 * Isar: implicit use of prems from the Isar proof context is
  1435 considered a legacy feature.  Common applications like ``have A .''
  1436 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1437 referencing facts explicitly here improves readability and
  1438 maintainability of proof texts.
  1439 
  1440 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1441 the obtained context from the course of reasoning!  For example:
  1442 
  1443   assume "EX x y. A x & B y"   -- "any previous fact"
  1444   then guess x and y by clarify
  1445 
  1446 This technique is potentially adventurous, depending on the facts and
  1447 proof tools being involved here.
  1448 
  1449 * Isar: known facts from the proof context may be specified as literal
  1450 propositions, using ASCII back-quote syntax.  This works wherever
  1451 named facts used to be allowed so far, in proof commands, proof
  1452 methods, attributes etc.  Literal facts are retrieved from the context
  1453 according to unification of type and term parameters.  For example,
  1454 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1455 theorems in the current context, then these are valid literal facts:
  1456 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1457 
  1458 There is also a proof method "fact" which does the same composition
  1459 for explicit goal states, e.g. the following proof texts coincide with
  1460 certain special cases of literal facts:
  1461 
  1462   have "A" by fact                 ==  note `A`
  1463   have "A ==> B" by fact           ==  note `A ==> B`
  1464   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1465   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1466 
  1467 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1468 outer syntax.  Thus symbolic identifiers may be used without
  1469 additional white space in declarations like this: ``assume *: A''.
  1470 
  1471 * Isar: 'print_facts' prints all local facts of the current context,
  1472 both named and unnamed ones.
  1473 
  1474 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1475 
  1476   def x == "t" and y == "u"
  1477 
  1478 * Isar: added command 'unfolding', which is structurally similar to
  1479 'using', but affects both the goal state and facts by unfolding given
  1480 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1481 'unfolded' attribute may be replaced by first-class proof text.
  1482 
  1483 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1484 and command 'unfolding' now all support object-level equalities
  1485 (potentially conditional).  The underlying notion of rewrite rule is
  1486 analogous to the 'rule_format' attribute, but *not* that of the
  1487 Simplifier (which is usually more generous).
  1488 
  1489 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1490 premises of a theorem by n. Useful in conjunction with drule.
  1491 
  1492 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1493 method expression within a sandbox consisting of the first N
  1494 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1495 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1496 simplifies all new goals that emerge from applying rule foo to the
  1497 originally first one.
  1498 
  1499 * Isar: schematic goals are no longer restricted to higher-order
  1500 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1501 expected.
  1502 
  1503 * Isar: the conclusion of a long theorem statement is now either
  1504 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1505 (essentially a disjunction of cases with local parameters and
  1506 assumptions).  The latter allows to express general elimination rules
  1507 adequately; in this notation common elimination rules look like this:
  1508 
  1509   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1510     assumes "EX x. P x"
  1511     obtains x where "P x"
  1512 
  1513   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1514     assumes "A & B"
  1515     obtains A and B
  1516 
  1517   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1518     assumes "A | B"
  1519     obtains
  1520       A
  1521     | B
  1522 
  1523 The subsequent classical rules even refer to the formal "thesis"
  1524 explicitly:
  1525 
  1526   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1527     obtains "~ thesis"
  1528 
  1529   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1530     obtains "thesis ==> something"
  1531 
  1532 The actual proof of an 'obtains' statement is analogous to that of the
  1533 Isar proof element 'obtain', only that there may be several cases.
  1534 Optional case names may be specified in parentheses; these will be
  1535 available both in the present proof and as annotations in the
  1536 resulting rule, for later use with the 'cases' method (cf. attribute
  1537 case_names).
  1538 
  1539 * Isar: the assumptions of a long theorem statement are available as
  1540 "assms" fact in the proof context.  This is more appropriate than the
  1541 (historical) "prems", which refers to all assumptions of the current
  1542 context, including those from the target locale, proof body etc.
  1543 
  1544 * Isar: 'print_statement' prints theorems from the current theory or
  1545 proof context in long statement form, according to the syntax of a
  1546 top-level lemma.
  1547 
  1548 * Isar: 'obtain' takes an optional case name for the local context
  1549 introduction rule (default "that").
  1550 
  1551 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1552 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1553 to occur.
  1554 
  1555 * Pure: syntax "CONST name" produces a fully internalized constant
  1556 according to the current context.  This is particularly useful for
  1557 syntax translations that should refer to internal constant
  1558 representations independently of name spaces.
  1559 
  1560 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1561 instead of "FOO ". This allows multiple binder declarations to coexist
  1562 in the same context.  INCOMPATIBILITY.
  1563 
  1564 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1565 primitive that also works in a locale context (both for constants and
  1566 fixed variables). Type declaration and internal syntactic representation
  1567 of given constants retrieved from the context. Likewise, the
  1568 'no_notation' command allows to remove given syntax annotations from the
  1569 current context.
  1570 
  1571 * Isar/locales: new derived specification elements 'axiomatization',
  1572 'definition', 'abbreviation', which support type-inference, admit
  1573 object-level specifications (equality, equivalence).  See also the
  1574 isar-ref manual.  Examples:
  1575 
  1576   axiomatization
  1577     eq  (infix "===" 50) where
  1578     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1579 
  1580   definition "f x y = x + y + 1"
  1581   definition g where "g x = f x x"
  1582 
  1583   abbreviation
  1584     neq  (infix "=!=" 50) where
  1585     "x =!= y == ~ (x === y)"
  1586 
  1587 These specifications may be also used in a locale context.  Then the
  1588 constants being introduced depend on certain fixed parameters, and the
  1589 constant name is qualified by the locale base name.  An internal
  1590 abbreviation takes care for convenient input and output, making the
  1591 parameters implicit and using the original short name.  See also
  1592 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1593 entities from a monomorphic theory.
  1594 
  1595 Presently, abbreviations are only available 'in' a target locale, but
  1596 not inherited by general import expressions.  Also note that
  1597 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1598 'translations' in common applications.  The "no_abbrevs" print mode
  1599 prevents folding of abbreviations in term output.
  1600 
  1601 Concrete syntax is attached to specified constants in internal form,
  1602 independently of name spaces.  The parse tree representation is
  1603 slightly different -- use 'notation' instead of raw 'syntax', and
  1604 'translations' with explicit "CONST" markup to accommodate this.
  1605 
  1606 * Pure/Isar: unified syntax for new-style specification mechanisms
  1607 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1608 full type inference and dummy patterns ("_").  For example:
  1609 
  1610   definition "K x _ = x"
  1611 
  1612   inductive conj for A B
  1613   where "A ==> B ==> conj A B"
  1614 
  1615 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1616 the current context.  Print mode "no_abbrevs" prevents inversion of
  1617 abbreviations on output.
  1618 
  1619 * Isar/locales: improved parameter handling: use of locales "var" and
  1620 "struct" no longer necessary; - parameter renamings are no longer
  1621 required to be injective.  For example, this allows to define
  1622 endomorphisms as locale endom = homom mult mult h.
  1623 
  1624 * Isar/locales: changed the way locales with predicates are defined.
  1625 Instead of accumulating the specification, the imported expression is
  1626 now an interpretation.  INCOMPATIBILITY: different normal form of
  1627 locale expressions.  In particular, in interpretations of locales with
  1628 predicates, goals repesenting already interpreted fragments are not
  1629 removed automatically.  Use methods `intro_locales' and
  1630 `unfold_locales'; see below.
  1631 
  1632 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1633 provide backward reasoning on locales predicates.  The methods are
  1634 aware of interpretations and discharge corresponding goals.
  1635 `intro_locales' is less aggressive then `unfold_locales' and does not
  1636 unfold predicates to assumptions.
  1637 
  1638 * Isar/locales: the order in which locale fragments are accumulated
  1639 has changed.  This enables to override declarations from fragments due
  1640 to interpretations -- for example, unwanted simp rules.
  1641 
  1642 * Isar/locales: interpretation in theories and proof contexts has been
  1643 extended.  One may now specify (and prove) equations, which are
  1644 unfolded in interpreted theorems.  This is useful for replacing
  1645 defined concepts (constants depending on locale parameters) by
  1646 concepts already existing in the target context.  Example:
  1647 
  1648   interpretation partial_order ["op <= :: [int, int] => bool"]
  1649     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1650 
  1651 Typically, the constant `partial_order.less' is created by a
  1652 definition specification element in the context of locale
  1653 partial_order.
  1654 
  1655 * Method "induct": improved internal context management to support
  1656 local fixes and defines on-the-fly. Thus explicit meta-level
  1657 connectives !!  and ==> are rarely required anymore in inductive goals
  1658 (using object-logic connectives for this purpose has been long
  1659 obsolete anyway). Common proof patterns are explained in
  1660 src/HOL/Induct/Common_Patterns.thy, see also
  1661 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1662 examples.
  1663 
  1664 * Method "induct": improved handling of simultaneous goals. Instead of
  1665 introducing object-level conjunction, the statement is now split into
  1666 several conclusions, while the corresponding symbolic cases are nested
  1667 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1668 see src/HOL/Induct/Common_Patterns.thy, for example.
  1669 
  1670 * Method "induct": mutual induction rules are now specified as a list
  1671 of rule sharing the same induction cases. HOL packages usually provide
  1672 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1673 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1674 mutual induction rules differently, i.e. like this:
  1675 
  1676   (induct rule: foo_bar.inducts)
  1677   (induct set: foo bar)
  1678   (induct pred: foo bar)
  1679   (induct type: foo bar)
  1680 
  1681 The ML function ProjectRule.projections turns old-style rules into the
  1682 new format.
  1683 
  1684 * Method "coinduct": dual of induction, see
  1685 src/HOL/Library/Coinductive_List.thy for various examples.
  1686 
  1687 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1688 considered a legacy feature.
  1689 
  1690 * Attribute "symmetric" produces result with standardized schematic
  1691 variables (index 0).  Potential INCOMPATIBILITY.
  1692 
  1693 * Simplifier: by default the simplifier trace only shows top level
  1694 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1695 default. Thus there is less danger of being flooded by the trace. The
  1696 trace indicates where parts have been suppressed.
  1697   
  1698 * Provers/classical: removed obsolete classical version of elim_format
  1699 attribute; classical elim/dest rules are now treated uniformly when
  1700 manipulating the claset.
  1701 
  1702 * Provers/classical: stricter checks to ensure that supplied intro,
  1703 dest and elim rules are well-formed; dest and elim rules must have at
  1704 least one premise.
  1705 
  1706 * Provers/classical: attributes dest/elim/intro take an optional
  1707 weight argument for the rule (just as the Pure versions).  Weights are
  1708 ignored by automated tools, but determine the search order of single
  1709 rule steps.
  1710 
  1711 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1712 where the body does not mention the bound variable.  Note that dummy
  1713 patterns implicitly depend on their context of bounds, which makes
  1714 "{_. _}" match any set comprehension as expected.  Potential
  1715 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1716 constant "_idtdummy" in the binding position.
  1717 
  1718 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1719 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1720 for example "A -> B" => "Pi A (%_. B)".
  1721 
  1722 * Pure: 'class_deps' command visualizes the subclass relation, using
  1723 the graph browser tool.
  1724 
  1725 * Pure: 'print_theory' now suppresses certain internal declarations by
  1726 default; use '!' option for full details.
  1727 
  1728 
  1729 *** HOL ***
  1730 
  1731 * Method "metis" proves goals by applying the Metis general-purpose
  1732 resolution prover (see also http://gilith.com/software/metis/).
  1733 Examples are in the directory MetisExamples.  WARNING: the
  1734 Isabelle/HOL-Metis integration does not yet work properly with
  1735 multi-threading.
  1736   
  1737 * Command 'sledgehammer' invokes external automatic theorem provers as
  1738 background processes.  It generates calls to the "metis" method if
  1739 successful. These can be pasted into the proof.  Users do not have to
  1740 wait for the automatic provers to return.  WARNING: does not really
  1741 work with multi-threading.
  1742 
  1743 * New "auto_quickcheck" feature tests outermost goal statements for
  1744 potential counter-examples.  Controlled by ML references
  1745 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1746 5000 milliseconds).  Fails silently if statements is outside of
  1747 executable fragment, or any other codgenerator problem occurs.
  1748 
  1749 * New constant "undefined" with axiom "undefined x = undefined".
  1750 
  1751 * Added class "HOL.eq", allowing for code generation with polymorphic
  1752 equality.
  1753 
  1754 * Some renaming of class constants due to canonical name prefixing in
  1755 the new 'class' package:
  1756 
  1757     HOL.abs ~> HOL.abs_class.abs
  1758     HOL.divide ~> HOL.divide_class.divide
  1759     0 ~> HOL.zero_class.zero
  1760     1 ~> HOL.one_class.one
  1761     op + ~> HOL.plus_class.plus
  1762     op - ~> HOL.minus_class.minus
  1763     uminus ~> HOL.minus_class.uminus
  1764     op * ~> HOL.times_class.times
  1765     op < ~> HOL.ord_class.less
  1766     op <= > HOL.ord_class.less_eq
  1767     Nat.power ~> Power.power_class.power
  1768     Nat.size ~> Nat.size_class.size
  1769     Numeral.number_of ~> Numeral.number_class.number_of
  1770     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1771     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1772     Orderings.min ~> Orderings.ord_class.min
  1773     Orderings.max ~> Orderings.ord_class.max
  1774     Divides.op div ~> Divides.div_class.div
  1775     Divides.op mod ~> Divides.div_class.mod
  1776     Divides.op dvd ~> Divides.div_class.dvd
  1777 
  1778 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1779 
  1780 a) User-defined constants using any of the names "plus", "minus",
  1781 "times", "less" or "less_eq". The standard syntax translations for
  1782 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1783 names.
  1784 
  1785 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1786 INCOMPATIBILITY: use more specific names.
  1787 
  1788 c) Permutative equations (e.g. "a + b = b + a")
  1789 Since the change of names also changes the order of terms, permutative
  1790 rewrite rules may get applied in a different order. Experience shows
  1791 that this is rarely the case (only two adaptions in the whole Isabelle
  1792 distribution).  INCOMPATIBILITY: rewrite proofs
  1793 
  1794 d) ML code directly refering to constant names
  1795 This in general only affects hand-written proof tactics, simprocs and
  1796 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1797 Consider using @{const_name} antiquotation.
  1798 
  1799 * New class "default" with associated constant "default".
  1800 
  1801 * Function "sgn" is now overloaded and available on int, real, complex
  1802 (and other numeric types), using class "sgn".  Two possible defs of
  1803 sgn are given as equational assumptions in the classes sgn_if and
  1804 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1805 INCOMPATIBILITY.
  1806 
  1807 * Locale "partial_order" now unified with class "order" (cf. theory
  1808 Orderings), added parameter "less".  INCOMPATIBILITY.
  1809 
  1810 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1811 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1812 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1813 
  1814 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1815 changed order of proof goals in instance proofs.
  1816 
  1817 * The transitivity reasoner for partial and linear orders is set up
  1818 for classes "order" and "linorder".  Instances of the reasoner are available
  1819 in all contexts importing or interpreting the corresponding locales.
  1820 Method "order" invokes the reasoner separately; the reasoner
  1821 is also integrated with the Simplifier as a solver.  Diagnostic
  1822 command 'print_orders' shows the available instances of the reasoner
  1823 in the current context.
  1824 
  1825 * Localized monotonicity predicate in theory "Orderings"; integrated
  1826 lemmas max_of_mono and min_of_mono with this predicate.
  1827 INCOMPATIBILITY.
  1828 
  1829 * Formulation of theorem "dense" changed slightly due to integration
  1830 with new class dense_linear_order.
  1831 
  1832 * Uniform lattice theory development in HOL.
  1833 
  1834     constants "meet" and "join" now named "inf" and "sup"
  1835     constant "Meet" now named "Inf"
  1836 
  1837     classes "meet_semilorder" and "join_semilorder" now named
  1838       "lower_semilattice" and "upper_semilattice"
  1839     class "lorder" now named "lattice"
  1840     class "comp_lat" now named "complete_lattice"
  1841 
  1842     Instantiation of lattice classes allows explicit definitions
  1843     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1844 
  1845   INCOMPATIBILITY.  Theorem renames:
  1846 
  1847     meet_left_le            ~> inf_le1
  1848     meet_right_le           ~> inf_le2
  1849     join_left_le            ~> sup_ge1
  1850     join_right_le           ~> sup_ge2
  1851     meet_join_le            ~> inf_sup_ord
  1852     le_meetI                ~> le_infI
  1853     join_leI                ~> le_supI
  1854     le_meet                 ~> le_inf_iff
  1855     le_join                 ~> ge_sup_conv
  1856     meet_idempotent         ~> inf_idem
  1857     join_idempotent         ~> sup_idem
  1858     meet_comm               ~> inf_commute
  1859     join_comm               ~> sup_commute
  1860     meet_leI1               ~> le_infI1
  1861     meet_leI2               ~> le_infI2
  1862     le_joinI1               ~> le_supI1
  1863     le_joinI2               ~> le_supI2
  1864     meet_assoc              ~> inf_assoc
  1865     join_assoc              ~> sup_assoc
  1866     meet_left_comm          ~> inf_left_commute
  1867     meet_left_idempotent    ~> inf_left_idem
  1868     join_left_comm          ~> sup_left_commute
  1869     join_left_idempotent    ~> sup_left_idem
  1870     meet_aci                ~> inf_aci
  1871     join_aci                ~> sup_aci
  1872     le_def_meet             ~> le_iff_inf
  1873     le_def_join             ~> le_iff_sup
  1874     join_absorp2            ~> sup_absorb2
  1875     join_absorp1            ~> sup_absorb1
  1876     meet_absorp1            ~> inf_absorb1
  1877     meet_absorp2            ~> inf_absorb2
  1878     meet_join_absorp        ~> inf_sup_absorb
  1879     join_meet_absorp        ~> sup_inf_absorb
  1880     distrib_join_le         ~> distrib_sup_le
  1881     distrib_meet_le         ~> distrib_inf_le
  1882 
  1883     add_meet_distrib_left   ~> add_inf_distrib_left
  1884     add_join_distrib_left   ~> add_sup_distrib_left
  1885     is_join_neg_meet        ~> is_join_neg_inf
  1886     is_meet_neg_join        ~> is_meet_neg_sup
  1887     add_meet_distrib_right  ~> add_inf_distrib_right
  1888     add_join_distrib_right  ~> add_sup_distrib_right
  1889     add_meet_join_distribs  ~> add_sup_inf_distribs
  1890     join_eq_neg_meet        ~> sup_eq_neg_inf
  1891     meet_eq_neg_join        ~> inf_eq_neg_sup
  1892     add_eq_meet_join        ~> add_eq_inf_sup
  1893     meet_0_imp_0            ~> inf_0_imp_0
  1894     join_0_imp_0            ~> sup_0_imp_0
  1895     meet_0_eq_0             ~> inf_0_eq_0
  1896     join_0_eq_0             ~> sup_0_eq_0
  1897     neg_meet_eq_join        ~> neg_inf_eq_sup
  1898     neg_join_eq_meet        ~> neg_sup_eq_inf
  1899     join_eq_if              ~> sup_eq_if
  1900 
  1901     mono_meet               ~> mono_inf
  1902     mono_join               ~> mono_sup
  1903     meet_bool_eq            ~> inf_bool_eq
  1904     join_bool_eq            ~> sup_bool_eq
  1905     meet_fun_eq             ~> inf_fun_eq
  1906     join_fun_eq             ~> sup_fun_eq
  1907     meet_set_eq             ~> inf_set_eq
  1908     join_set_eq             ~> sup_set_eq
  1909     meet1_iff               ~> inf1_iff
  1910     meet2_iff               ~> inf2_iff
  1911     meet1I                  ~> inf1I
  1912     meet2I                  ~> inf2I
  1913     meet1D1                 ~> inf1D1
  1914     meet2D1                 ~> inf2D1
  1915     meet1D2                 ~> inf1D2
  1916     meet2D2                 ~> inf2D2
  1917     meet1E                  ~> inf1E
  1918     meet2E                  ~> inf2E
  1919     join1_iff               ~> sup1_iff
  1920     join2_iff               ~> sup2_iff
  1921     join1I1                 ~> sup1I1
  1922     join2I1                 ~> sup2I1
  1923     join1I1                 ~> sup1I1
  1924     join2I2                 ~> sup1I2
  1925     join1CI                 ~> sup1CI
  1926     join2CI                 ~> sup2CI
  1927     join1E                  ~> sup1E
  1928     join2E                  ~> sup2E
  1929 
  1930     is_meet_Meet            ~> is_meet_Inf
  1931     Meet_bool_def           ~> Inf_bool_def
  1932     Meet_fun_def            ~> Inf_fun_def
  1933     Meet_greatest           ~> Inf_greatest
  1934     Meet_lower              ~> Inf_lower
  1935     Meet_set_def            ~> Inf_set_def
  1936 
  1937     Sup_def                 ~> Sup_Inf
  1938     Sup_bool_eq             ~> Sup_bool_def
  1939     Sup_fun_eq              ~> Sup_fun_def
  1940     Sup_set_eq              ~> Sup_set_def
  1941 
  1942     listsp_meetI            ~> listsp_infI
  1943     listsp_meet_eq          ~> listsp_inf_eq
  1944 
  1945     meet_min                ~> inf_min
  1946     join_max                ~> sup_max
  1947 
  1948 * Added syntactic class "size"; overloaded constant "size" now has
  1949 type "'a::size ==> bool"
  1950 
  1951 * Internal reorganisation of `size' of datatypes: size theorems
  1952 "foo.size" are no longer subsumed by "foo.simps" (but are still
  1953 simplification rules by default!); theorems "prod.size" now named
  1954 "*.size".
  1955 
  1956 * Class "div" now inherits from class "times" rather than "type".
  1957 INCOMPATIBILITY.
  1958 
  1959 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  1960 Linorder etc.  have disappeared; operations defined in terms of
  1961 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  1962 
  1963 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  1964 
  1965 * HOL-Word: New extensive library and type for generic, fixed size
  1966 machine words, with arithemtic, bit-wise, shifting and rotating
  1967 operations, reflection into int, nat, and bool lists, automation for
  1968 linear arithmetic (by automatic reflection into nat or int), including
  1969 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  1970 arithmetic type classes, supporting automatic simplification of
  1971 numerals on all operations.
  1972 
  1973 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  1974 
  1975 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  1976 
  1977 * Code generator library theories:
  1978   - Code_Integer represents HOL integers by big integer literals in target
  1979     languages.
  1980   - Code_Char represents HOL characters by character literals in target
  1981     languages.
  1982   - Code_Char_chr like Code_Char, but also offers treatment of character
  1983     codes; includes Code_Integer.
  1984   - Executable_Set allows to generate code for finite sets using lists.
  1985   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  1986     denominator).
  1987   - Executable_Real implements a subset of real numbers, namly those
  1988     representable by rational numbers.
  1989   - Efficient_Nat implements natural numbers by integers, which in general will
  1990     result in higher efficency; pattern matching with 0/Suc is eliminated;
  1991     includes Code_Integer.
  1992   - Code_Index provides an additional datatype index which is mapped to
  1993     target-language built-in integers.
  1994   - Code_Message provides an additional datatype message_string which is isomorphic to
  1995     strings; messages are mapped to target-language strings.
  1996 
  1997 * New package for inductive predicates
  1998 
  1999   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2000 
  2001     inductive
  2002       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2003       for z_1 :: U_1 and ... and z_n :: U_m
  2004     where
  2005       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2006     | ...
  2007 
  2008   with full support for type-inference, rather than
  2009 
  2010     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2011 
  2012     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2013     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2014 
  2015     inductive "s z_1 ... z_m"
  2016     intros
  2017       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2018       ...
  2019 
  2020   For backward compatibility, there is a wrapper allowing inductive
  2021   sets to be defined with the new package via
  2022 
  2023     inductive_set
  2024       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2025       for z_1 :: U_1 and ... and z_n :: U_m
  2026     where
  2027       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2028     | ...
  2029 
  2030   or
  2031 
  2032     inductive_set
  2033       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2034       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2035       for z_1 :: U_1 and ... and z_n :: U_m
  2036     where
  2037       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2038     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2039     | ...
  2040 
  2041   if the additional syntax "p ..." is required.
  2042 
  2043   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2044   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2045 
  2046   INCOMPATIBILITIES:
  2047 
  2048   - Since declaration and definition of inductive sets or predicates
  2049     is no longer separated, abbreviations involving the newly
  2050     introduced sets or predicates must be specified together with the
  2051     introduction rules after the 'where' keyword (see above), rather
  2052     than before the actual inductive definition.
  2053 
  2054   - The variables in induction and elimination rules are now
  2055     quantified in the order of their occurrence in the introduction
  2056     rules, rather than in alphabetical order. Since this may break
  2057     some proofs, these proofs either have to be repaired, e.g. by
  2058     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2059     statements of the form
  2060 
  2061       case (rule_i a_i_1 ... a_i_{k_i})
  2062 
  2063     or the old order of quantification has to be restored by explicitly adding
  2064     meta-level quantifiers in the introduction rules, i.e.
  2065 
  2066       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2067 
  2068   - The format of the elimination rules is now
  2069 
  2070       p z_1 ... z_m x_1 ... x_n ==>
  2071         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2072         ==> ... ==> P
  2073 
  2074     for predicates and
  2075 
  2076       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2077         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2078         ==> ... ==> P
  2079 
  2080     for sets rather than
  2081 
  2082       x : s z_1 ... z_m ==>
  2083         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2084         ==> ... ==> P
  2085 
  2086     This may require terms in goals to be expanded to n-tuples
  2087     (e.g. using case_tac or simplification with the split_paired_all
  2088     rule) before the above elimination rule is applicable.
  2089 
  2090   - The elimination or case analysis rules for (mutually) inductive
  2091     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2092     list of rules "p_1_..._p_k.elims" is no longer available.
  2093 
  2094 * New package "function"/"fun" for general recursive functions,
  2095 supporting mutual and nested recursion, definitions in local contexts,
  2096 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2097 for small examples, and the separate tutorial on the function
  2098 package. The old recdef "package" is still available as before, but
  2099 users are encouraged to use the new package.
  2100 
  2101 * Method "lexicographic_order" automatically synthesizes termination
  2102 relations as lexicographic combinations of size measures. 
  2103 
  2104 * Case-expressions allow arbitrary constructor-patterns (including
  2105 "_") and take their order into account, like in functional
  2106 programming.  Internally, this is translated into nested
  2107 case-expressions; missing cases are added and mapped to the predefined
  2108 constant "undefined". In complicated cases printing may no longer show
  2109 the original input but the internal form. Lambda-abstractions allow
  2110 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2111 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2112 variable.
  2113 
  2114 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2115 is an abbreviation for "of_nat :: nat => int". The simplification
  2116 rules for "of_nat" have been changed to work like "int" did
  2117 previously.  Potential INCOMPATIBILITY:
  2118   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2119   - of_nat_diff and of_nat_mult are no longer default simp rules
  2120 
  2121 * Method "algebra" solves polynomial equations over (semi)rings using
  2122 Groebner bases. The (semi)ring structure is defined by locales and the
  2123 tool setup depends on that generic context. Installing the method for
  2124 a specific type involves instantiating the locale and possibly adding
  2125 declarations for computation on the coefficients.  The method is
  2126 already instantiated for natural numbers and for the axiomatic class
  2127 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2128 CALCULEMUS 2007 for the general principles underlying this
  2129 architecture of context-aware proof-tools.
  2130 
  2131 * Method "ferrack" implements quantifier elimination over
  2132 special-purpose dense linear orders using locales (analogous to
  2133 "algebra"). The method is already installed for class
  2134 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2135 rat, etc.
  2136 
  2137 * Former constant "List.op @" now named "List.append".  Use ML
  2138 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2139 circumvent possible incompatibilities when working on ML level.
  2140 
  2141 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2142 
  2143 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2144 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2145 
  2146 * New syntax for Haskell-like list comprehension (input only), eg.
  2147 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2148 
  2149 * The special syntax for function "filter" has changed from [x :
  2150 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2151 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2152 
  2153 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2154 defined on nat only, as an abbreviation for [a..<Suc b]
  2155 INCOMPATIBILITY.
  2156 
  2157 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2158 
  2159 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2160 
  2161 * New lemma collection field_simps (an extension of ring_simps) for
  2162 manipulating (in)equations involving division. Multiplies with all
  2163 denominators that can be proved to be non-zero (in equations) or
  2164 positive/negative (in inequations).
  2165 
  2166 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2167 have been improved and renamed to ring_simps, group_simps and
  2168 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2169 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2170 
  2171 * Theory Library/Commutative_Ring: switched from recdef to function
  2172 package; constants add, mul, pow now curried.  Infix syntax for
  2173 algebraic operations.
  2174 
  2175 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2176 INCOMPATIBILITY.
  2177 
  2178 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2179 INCOMPATIBILITY.
  2180 
  2181 * HOL/records: generalised field-update to take a function on the
  2182 field rather than the new value: r(|A := x|) is translated to A_update
  2183 (K x) r The K-combinator that is internally used is called K_record.
  2184 INCOMPATIBILITY: Usage of the plain update functions has to be
  2185 adapted.
  2186  
  2187 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2188 * x = 0, which are required for a semiring.  Richer structures do not
  2189 inherit from semiring_0 anymore, because this property is a theorem
  2190 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2191 there is more to prove, but this is mostly trivial.
  2192 
  2193 * Class "recpower" is generalized to arbitrary monoids, not just
  2194 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2195 commutativity or semiring properties additionally.
  2196 
  2197 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2198 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2199 better use 'abbreviation'.
  2200 
  2201 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2202 
  2203 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2204 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2205 significant changes for setting up numeral syntax for types:
  2206   - New constants Numeral.pred and Numeral.succ instead
  2207       of former Numeral.bin_pred and Numeral.bin_succ.
  2208   - Use integer operations instead of bin_add, bin_mult and so on.
  2209   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2210   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2211 
  2212 See src/HOL/Integ/IntArith.thy for an example setup.
  2213 
  2214 * Command 'normal_form' computes the normal form of a term that may
  2215 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2216 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2217 heavy-duty computations because the functions are compiled to ML
  2218 first.  Correspondingly, a method "normalization" is provided.  See
  2219 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2220 
  2221 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2222 25 like -->); output depends on the "iff" print_mode, the default is
  2223 "A = B" (with priority 50).
  2224 
  2225 * Relations less (<) and less_eq (<=) are also available on type bool.
  2226 Modified syntax to disallow nesting without explicit parentheses,
  2227 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2228 INCOMPATIBILITY.
  2229 
  2230 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2231 
  2232 * Relation composition operator "op O" now has precedence 75 and binds
  2233 stronger than union and intersection. INCOMPATIBILITY.
  2234 
  2235 * The old set interval syntax "{m..n(}" (and relatives) has been
  2236 removed.  Use "{m..<n}" (and relatives) instead.
  2237 
  2238 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2239 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2240 ``declare [[simproc del: neq]]''.
  2241 
  2242 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2243 True/False.
  2244 
  2245 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2246 
  2247 * Theorem setsum_mult renamed to setsum_right_distrib.
  2248 
  2249 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2250 ``rule'' method.
  2251 
  2252 * Reimplemented methods "sat" and "satx", with several improvements:
  2253 goals no longer need to be stated as "<prems> ==> False", equivalences
  2254 (i.e. "=" on type bool) are handled, variable names of the form
  2255 "lit_<n>" are no longer reserved, significant speedup.
  2256 
  2257 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2258 zChaff is still supported as well.
  2259 
  2260 * 'inductive' and 'datatype': provide projections of mutual rules,
  2261 bundled as foo_bar.inducts;
  2262 
  2263 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2264 Library.
  2265 
  2266 * Library: moved theory Accessible_Part to main HOL.
  2267 
  2268 * Library: added theory Coinductive_List of potentially infinite lists
  2269 as greatest fixed-point.
  2270 
  2271 * Library: added theory AssocList which implements (finite) maps as
  2272 association lists.
  2273 
  2274 * Method "evaluation" solves goals (i.e. a boolean expression)
  2275 efficiently by compiling it to ML.  The goal is "proved" (via an
  2276 oracle) if it evaluates to True.
  2277 
  2278 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2279 also when invoked by the simplifier.  This results in the Simplifier
  2280 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2281 Configuration option fast_arith_split_limit=0 recovers the old
  2282 behavior.
  2283 
  2284 * Support for hex (0x20) and binary (0b1001) numerals.
  2285 
  2286 * New method: reify eqs (t), where eqs are equations for an
  2287 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2288 parameter, computes a term s::'b and a list xs::'a list and proves the
  2289 theorem I xs s = t. This is also known as reification or quoting. The
  2290 resulting theorem is applied to the subgoal to substitute t with I xs
  2291 s.  If t is omitted, the subgoal itself is reified.
  2292 
  2293 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2294 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2295 where f is supposed to be a computable function (in the sense of code
  2296 generattion). The method uses reify to compute s and xs as above then
  2297 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2298 r and finally gets the theorem t = r, which is again applied to the
  2299 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2300 
  2301 * Reflection: Automatic reification now handels binding, an example is
  2302 available in src/HOL/ex/ReflectionEx.thy
  2303 
  2304 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2305 command 'statespace' that is similar to 'record', but introduces an
  2306 abstract specification based on the locale infrastructure instead of
  2307 HOL types.  This leads to extra flexibility in composing state spaces,
  2308 in particular multiple inheritance and renaming of components.
  2309 
  2310 
  2311 *** HOL-Complex ***
  2312 
  2313 * Hyperreal: Functions root and sqrt are now defined on negative real
  2314 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2315 Nonnegativity side conditions have been removed from many lemmas, so
  2316 that more subgoals may now be solved by simplification; potential
  2317 INCOMPATIBILITY.
  2318 
  2319 * Real: new type classes formalize real normed vector spaces and
  2320 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2321 and norm :: 'a => real.
  2322 
  2323 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2324 reals into other types. The overloaded constant Reals :: 'a set is now
  2325 defined as range of_real; potential INCOMPATIBILITY.
  2326 
  2327 * Real: proper support for ML code generation, including 'quickcheck'.
  2328 Reals are implemented as arbitrary precision rationals.
  2329 
  2330 * Hyperreal: Several constants that previously worked only for the
  2331 reals have been generalized, so they now work over arbitrary vector
  2332 spaces. Type annotations may need to be added in some cases; potential
  2333 INCOMPATIBILITY.
  2334 
  2335   Infinitesimal  :: ('a::real_normed_vector) star set
  2336   HFinite        :: ('a::real_normed_vector) star set
  2337   HInfinite      :: ('a::real_normed_vector) star set
  2338   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2339   monad          :: ('a::real_normed_vector) star => 'a star set
  2340   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2341   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2342   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2343   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2344   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2345   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2346   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2347   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2348   sgn            :: 'a::real_normed_vector => 'a
  2349   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2350 
  2351 * Complex: Some complex-specific constants are now abbreviations for
  2352 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2353 hnorm.  Other constants have been entirely removed in favor of the
  2354 polymorphic versions (INCOMPATIBILITY):
  2355 
  2356   approx        <-- capprox
  2357   HFinite       <-- CFinite
  2358   HInfinite     <-- CInfinite
  2359   Infinitesimal <-- CInfinitesimal
  2360   monad         <-- cmonad
  2361   galaxy        <-- cgalaxy
  2362   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2363   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2364   (ns)deriv     <-- (ns)cderiv
  2365 
  2366 
  2367 *** HOL-Algebra ***
  2368 
  2369 * Formalisation of ideals and the quotient construction over rings.
  2370 
  2371 * Order and lattice theory no longer based on records.
  2372 INCOMPATIBILITY.
  2373 
  2374 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2375 greatest_closed.  INCOMPATIBILITY.
  2376 
  2377 * Method algebra is now set up via an attribute.  For examples see
  2378 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2379 of algebraic structures.
  2380 
  2381 * Renamed theory CRing to Ring.
  2382 
  2383 
  2384 *** HOL-Nominal ***
  2385 
  2386 * Substantial, yet incomplete support for nominal datatypes (binding
  2387 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2388 src/HOL/Nominal/Examples.  Prospective users should consult
  2389 http://isabelle.in.tum.de/nominal/
  2390 
  2391 
  2392 *** ML ***
  2393 
  2394 * ML basics: just one true type int, which coincides with IntInf.int
  2395 (even on SML/NJ).
  2396 
  2397 * ML within Isar: antiquotations allow to embed statically-checked
  2398 formal entities in the source, referring to the context available at
  2399 compile-time.  For example:
  2400 
  2401 ML {* @{sort "{zero,one}"} *}
  2402 ML {* @{typ "'a => 'b"} *}
  2403 ML {* @{term "%x. x"} *}
  2404 ML {* @{prop "x == y"} *}
  2405 ML {* @{ctyp "'a => 'b"} *}
  2406 ML {* @{cterm "%x. x"} *}
  2407 ML {* @{cprop "x == y"} *}
  2408 ML {* @{thm asm_rl} *}
  2409 ML {* @{thms asm_rl} *}
  2410 ML {* @{type_name c} *}
  2411 ML {* @{type_syntax c} *}
  2412 ML {* @{const_name c} *}
  2413 ML {* @{const_syntax c} *}
  2414 ML {* @{context} *}
  2415 ML {* @{theory} *}
  2416 ML {* @{theory Pure} *}
  2417 ML {* @{theory_ref} *}
  2418 ML {* @{theory_ref Pure} *}
  2419 ML {* @{simpset} *}
  2420 ML {* @{claset} *}
  2421 ML {* @{clasimpset} *}
  2422 
  2423 The same works for sources being ``used'' within an Isar context.
  2424 
  2425 * ML in Isar: improved error reporting; extra verbosity with
  2426 ML_Context.trace enabled.
  2427 
  2428 * Pure/General/table.ML: the join operations now works via exceptions
  2429 DUP/SAME instead of type option. This is simpler in simple cases, and
  2430 admits slightly more efficient complex applications.
  2431 
  2432 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2433 use Context.generic instead of just theory.
  2434 
  2435 * Pure: datatype Context.generic joins theory/Proof.context and
  2436 provides some facilities for code that works in either kind of
  2437 context, notably GenericDataFun for uniform theory and proof data.
  2438 
  2439 * Pure: simplified internal attribute type, which is now always
  2440 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2441 local (Proof.context) attributes have been discontinued, while
  2442 minimizing code duplication. Thm.rule_attribute and
  2443 Thm.declaration_attribute build canonical attributes; see also structure
  2444 Context for further operations on Context.generic, notably
  2445 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2446 declarations and definitions.
  2447 
  2448 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2449 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2450 init only required for impure data. INCOMPATIBILITY: empty really need
  2451 to be empty (no dependencies on theory content!)
  2452 
  2453 * Pure/kernel: consts certification ignores sort constraints given in
  2454 signature declarations. (This information is not relevant to the
  2455 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2456 potential INCOMPATIBILITY.
  2457 
  2458 * Pure: axiomatic type classes are now purely definitional, with
  2459 explicit proofs of class axioms and super class relations performed
  2460 internally. See Pure/axclass.ML for the main internal interfaces --
  2461 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2462 AxClass.axiomatize_class/classrel/arity supersede
  2463 Sign.add_classes/classrel/arities.
  2464 
  2465 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2466 global/local versions on theory vs. Proof.context have been
  2467 discontinued; Attrib.syntax and Method.syntax have been adapted
  2468 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2469 attributes, methods, etc.
  2470 
  2471 * Pure: several functions of signature "... -> theory -> theory * ..."
  2472 have been reoriented to "... -> theory -> ... * theory" in order to
  2473 allow natural usage in combination with the ||>, ||>>, |-> and
  2474 fold_map combinators.
  2475 
  2476 * Pure: official theorem names (closed derivations) and additional
  2477 comments (tags) are now strictly separate.  Name hints -- which are
  2478 maintained as tags -- may be attached any time without affecting the
  2479 derivation.
  2480 
  2481 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2482 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2483 achieve the old behaviour.
  2484 
  2485 * Pure: the "Goal" constant is now called "prop", supporting a
  2486 slightly more general idea of ``protecting'' meta-level rule
  2487 statements.
  2488 
  2489 * Pure: Logic.(un)varify only works in a global context, which is now
  2490 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2491 Logic.legacy_(un)varify as temporary workaround.
  2492 
  2493 * Pure: structure Name provides scalable operations for generating
  2494 internal variable names, notably Name.variants etc.  This replaces
  2495 some popular functions from term.ML:
  2496 
  2497   Term.variant		->  Name.variant
  2498   Term.variantlist	->  Name.variant_list
  2499   Term.invent_names	->  Name.invent_list
  2500 
  2501 Note that low-level renaming rarely occurs in new code -- operations
  2502 from structure Variable are used instead (see below).
  2503 
  2504 * Pure: structure Variable provides fundamental operations for proper
  2505 treatment of fixed/schematic variables in a context.  For example,
  2506 Variable.import introduces fixes for schematics of given facts and
  2507 Variable.export reverses the effect (up to renaming) -- this replaces
  2508 various freeze_thaw operations.
  2509 
  2510 * Pure: structure Goal provides simple interfaces for
  2511 init/conclude/finish and tactical prove operations (replacing former
  2512 Tactic.prove).  Goal.prove is the canonical way to prove results
  2513 within a given context; Goal.prove_global is a degraded version for
  2514 theory level goals, including a global Drule.standard.  Note that
  2515 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2516 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2517 in a locale context).
  2518 
  2519 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2520 and type checking (Syntax.check_term etc.), with common combinations
  2521 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2522 which are considered legacy and await removal.
  2523 
  2524 * Pure/Syntax: generic interfaces for type unchecking
  2525 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2526 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2527 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2528 available for convenience, but refer to the very same operations using
  2529 a mere theory instead of a full context.
  2530 
  2531 * Isar: simplified treatment of user-level errors, using exception
  2532 ERROR of string uniformly.  Function error now merely raises ERROR,
  2533 without any side effect on output channels.  The Isar toplevel takes
  2534 care of proper display of ERROR exceptions.  ML code may use plain
  2535 handle/can/try; cat_error may be used to concatenate errors like this:
  2536 
  2537   ... handle ERROR msg => cat_error msg "..."
  2538 
  2539 Toplevel ML code (run directly or through the Isar toplevel) may be
  2540 embedded into the Isar toplevel with exception display/debug like
  2541 this:
  2542 
  2543   Isar.toplevel (fn () => ...)
  2544 
  2545 INCOMPATIBILITY, removed special transform_error facilities, removed
  2546 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2547 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2548 -- use plain ERROR instead.
  2549 
  2550 * Isar: theory setup now has type (theory -> theory), instead of a
  2551 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2552 
  2553 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2554 ProofContext.debug/verbose flags.
  2555 
  2556 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2557 theory before entering a proof state.  Transactions now always see a
  2558 quasi-functional intermediate checkpoint, both in interactive and
  2559 batch mode.
  2560 
  2561 * Isar: simplified interfaces for outer syntax.  Renamed
  2562 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2563 OuterSyntax.add_parsers -- this functionality is now included in
  2564 OuterSyntax.command etc.  INCOMPATIBILITY.
  2565 
  2566 * Simplifier: the simpset of a running simplification process now
  2567 contains a proof context (cf. Simplifier.the_context), which is the
  2568 very context that the initial simpset has been retrieved from (by
  2569 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2570 (solver, looper etc.) may depend on arbitrary proof data.
  2571 
  2572 * Simplifier.inherit_context inherits the proof context (plus the
  2573 local bounds) of the current simplification process; any simproc
  2574 etc. that calls the Simplifier recursively should do this!  Removed
  2575 former Simplifier.inherit_bounds, which is already included here --
  2576 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2577 specify an explicit context using Simplifier.context/theory_context.
  2578 
  2579 * Simplifier/Classical Reasoner: more abstract interfaces
  2580 change_simpset/claset for modifying the simpset/claset reference of a
  2581 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2582 INCOMPATIBILITY.
  2583 
  2584 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2585 "Trueprop" etc.
  2586 
  2587 
  2588 *** System ***
  2589 
  2590 * settings: the default heap location within ISABELLE_HOME_USER now
  2591 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2592 Isabelle installations.
  2593 
  2594 * isabelle-process: option -S (secure mode) disables some critical
  2595 operations, notably runtime compilation and evaluation of ML source
  2596 code.
  2597 
  2598 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2599 
  2600 * Support for parallel execution, using native multicore support of
  2601 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2602 independent theories, according to the given theory header
  2603 specifications. The maximum number of worker threads is specified via
  2604 usedir option -M or the "max-threads" setting in Proof General. A
  2605 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2606 to 6 on a 8-core machine.  User-code needs to observe certain
  2607 guidelines for thread-safe programming, see appendix A in the Isar
  2608 Implementation manual.
  2609 
  2610 
  2611 
  2612 New in Isabelle2005 (October 2005)
  2613 ----------------------------------
  2614 
  2615 *** General ***
  2616 
  2617 * Theory headers: the new header syntax for Isar theories is
  2618 
  2619   theory <name>
  2620   imports <theory1> ... <theoryN>
  2621   uses <file1> ... <fileM>
  2622   begin
  2623 
  2624 where the 'uses' part is optional.  The previous syntax
  2625 
  2626   theory <name> = <theory1> + ... + <theoryN>:
  2627 
  2628 will disappear in the next release.  Use isatool fixheaders to convert
  2629 existing theory files.  Note that there is no change in ancient
  2630 non-Isar theories now, but these will disappear soon.
  2631 
  2632 * Theory loader: parent theories can now also be referred to via
  2633 relative and absolute paths.
  2634 
  2635 * Command 'find_theorems' searches for a list of criteria instead of a
  2636 list of constants. Known criteria are: intro, elim, dest, name:string,
  2637 simp:term, and any term. Criteria can be preceded by '-' to select
  2638 theorems that do not match. Intro, elim, dest select theorems that
  2639 match the current goal, name:s selects theorems whose fully qualified
  2640 name contain s, and simp:term selects all simplification rules whose
  2641 lhs match term.  Any other term is interpreted as pattern and selects
  2642 all theorems matching the pattern. Available in ProofGeneral under
  2643 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2644 
  2645   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2646 
  2647 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2648 matching the current goal as introduction rule and not having "HOL."
  2649 in their name (i.e. not being defined in theory HOL).
  2650 
  2651 * Command 'thms_containing' has been discontinued in favour of
  2652 'find_theorems'; INCOMPATIBILITY.
  2653 
  2654 * Communication with Proof General is now 8bit clean, which means that
  2655 Unicode text in UTF-8 encoding may be used within theory texts (both
  2656 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2657 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2658 
  2659   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2660   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2661 
  2662 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2663 Classical Reasoner.  Typical big applications run around 2 times
  2664 faster.
  2665 
  2666 
  2667 *** Document preparation ***
  2668 
  2669 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2670 of raw sources.  Only those symbols that do not require additional
  2671 LaTeX packages (depending on comments in isabellesym.sty) are
  2672 displayed properly, everything else is left verbatim.  isatool display
  2673 and isatool print are used as front ends (these are subject to the
  2674 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2675 
  2676 * Command tags control specific markup of certain regions of text,
  2677 notably folding and hiding.  Predefined tags include "theory" (for
  2678 theory begin and end), "proof" for proof commands, and "ML" for
  2679 commands involving ML code; the additional tags "visible" and
  2680 "invisible" are unused by default.  Users may give explicit tag
  2681 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2682 interpretation of tags is determined by the LaTeX job during document
  2683 preparation: see option -V of isatool usedir, or options -n and -t of
  2684 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2685 \isadroptag.
  2686 
  2687 Several document versions may be produced at the same time via isatool
  2688 usedir (the generated index.html will link all of them).  Typical
  2689 specifications include ''-V document=theory,proof,ML'' to present
  2690 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2691 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2692 these parts without any formal replacement text.  The Isabelle site
  2693 default settings produce ''document'' and ''outline'' versions as
  2694 specified above.
  2695 
  2696 * Several new antiquotations:
  2697 
  2698   @{term_type term} prints a term with its type annotated;
  2699 
  2700   @{typeof term} prints the type of a term;
  2701 
  2702   @{const const} is the same as @{term const}, but checks that the
  2703   argument is a known logical constant;
  2704 
  2705   @{term_style style term} and @{thm_style style thm} print a term or
  2706   theorem applying a "style" to it
  2707 
  2708   @{ML text}
  2709 
  2710 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2711 definitions, equations, inequations etc., 'concl' printing only the
  2712 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2713 to print the specified premise.  TermStyle.add_style provides an ML
  2714 interface for introducing further styles.  See also the "LaTeX Sugar"
  2715 document practical applications.  The ML antiquotation prints
  2716 type-checked ML expressions verbatim.
  2717 
  2718 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2719 and 'text' support optional locale specification '(in loc)', which
  2720 specifies the default context for interpreting antiquotations.  For
  2721 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2722 
  2723 * Option 'locale=NAME' of antiquotations specifies an alternative
  2724 context interpreting the subsequent argument.  For example: @{thm
  2725 [locale=lattice] inf_assoc}.
  2726 
  2727 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2728 a proof context.
  2729 
  2730 * Proper output of antiquotations for theory commands involving a
  2731 proof context (such as 'locale' or 'theorem (in loc) ...').
  2732 
  2733 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2734 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2735 
  2736 * isatool usedir: new option -C (default true) controls whether option
  2737 -D should include a copy of the original document directory; -C false
  2738 prevents unwanted effects such as copying of administrative CVS data.
  2739 
  2740 
  2741 *** Pure ***
  2742 
  2743 * Considerably improved version of 'constdefs' command.  Now performs
  2744 automatic type-inference of declared constants; additional support for
  2745 local structure declarations (cf. locales and HOL records), see also
  2746 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2747 sequential dependencies of definitions within a single 'constdefs'
  2748 section; moreover, the declared name needs to be an identifier.  If
  2749 all fails, consider to fall back on 'consts' and 'defs' separately.
  2750 
  2751 * Improved indexed syntax and implicit structures.  First of all,
  2752 indexed syntax provides a notational device for subscripted
  2753 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2754 expressions.  Secondly, in a local context with structure
  2755 declarations, number indexes \<^sub>n or the empty index (default
  2756 number 1) refer to a certain fixed variable implicitly; option
  2757 show_structs controls printing of implicit structures.  Typical
  2758 applications of these concepts involve record types and locales.
  2759 
  2760 * New command 'no_syntax' removes grammar declarations (and
  2761 translations) resulting from the given syntax specification, which is
  2762 interpreted in the same manner as for the 'syntax' command.
  2763 
  2764 * 'Advanced' translation functions (parse_translation etc.) may depend
  2765 on the signature of the theory context being presently used for
  2766 parsing/printing, see also isar-ref manual.
  2767 
  2768 * Improved 'oracle' command provides a type-safe interface to turn an
  2769 ML expression of type theory -> T -> term into a primitive rule of
  2770 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2771 is already included here); see also FOL/ex/IffExample.thy;
  2772 INCOMPATIBILITY.
  2773 
  2774 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2775 before); "cI" is no longer bound, use "c.intro" instead.
  2776 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2777 axclasses vs. locales.
  2778 
  2779 * Improved internal renaming of symbolic identifiers -- attach primes
  2780 instead of base 26 numbers.
  2781 
  2782 * New flag show_question_marks controls printing of leading question
  2783 marks in schematic variable names.
  2784 
  2785 * In schematic variable names, *any* symbol following \<^isub> or
  2786 \<^isup> is now treated as part of the base name.  For example, the
  2787 following works without printing of awkward ".0" indexes:
  2788 
  2789   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2790     by simp
  2791 
  2792 * Inner syntax includes (*(*nested*) comments*).
  2793 
  2794 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2795 annotations as "(00...)".
  2796 
  2797 * Clear separation of logical types and nonterminals, where the latter
  2798 may only occur in 'syntax' specifications or type abbreviations.
  2799 Before that distinction was only partially implemented via type class
  2800 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2801 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2802 exotic syntax specifications may require further adaption
  2803 (e.g. Cube/Cube.thy).
  2804 
  2805 * Removed obsolete type class "logic", use the top sort {} instead.
  2806 Note that non-logical types should be declared as 'nonterminals'
  2807 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2808 specifications.
  2809 
  2810 * Attributes 'induct' and 'cases': type or set names may now be
  2811 locally fixed variables as well.
  2812 
  2813 * Simplifier: can now control the depth to which conditional rewriting
  2814 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2815 Limit.
  2816 
  2817 * Simplifier: simplification procedures may now take the current
  2818 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2819 interface), which is very useful for calling the Simplifier
  2820 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2821 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2822 low-level mk_simproc no longer applies Logic.varify internally, to
  2823 allow for use in a context of fixed variables.
  2824 
  2825 * thin_tac now works even if the assumption being deleted contains !!
  2826 or ==>.  More generally, erule now works even if the major premise of
  2827 the elimination rule contains !! or ==>.
  2828 
  2829 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2830 
  2831 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2832 from Pure, which contains all common declarations already.  Both
  2833 theories are defined via plain Isabelle/Isar .thy files.
  2834 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2835 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2836 use isatool fixcpure to adapt your theory and ML sources.
  2837 
  2838 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2839 selections of theorems in named facts via index ranges.
  2840 
  2841 * 'print_theorems': in theory mode, really print the difference
  2842 wrt. the last state (works for interactive theory development only),
  2843 in proof mode print all local facts (cf. 'print_facts');
  2844 
  2845 * 'hide': option '(open)' hides only base names.
  2846 
  2847 * More efficient treatment of intermediate checkpoints in interactive
  2848 theory development.
  2849 
  2850 * Code generator is now invoked via code_module (incremental code
  2851 generation) and code_library (modular code generation, ML structures
  2852 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2853 must be quoted when used as identifiers.
  2854 
  2855 * New 'value' command for reading, evaluating and printing terms using
  2856 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2857 quoted when used as identifier.
  2858 
  2859 
  2860 *** Locales ***
  2861 
  2862 * New commands for the interpretation of locale expressions in
  2863 theories (1), locales (2) and proof contexts (3).  These generate
  2864 proof obligations from the expression specification.  After the
  2865 obligations have been discharged, theorems of the expression are added
  2866 to the theory, target locale or proof context.  The synopsis of the
  2867 commands is a follows:
  2868 
  2869   (1) interpretation expr inst
  2870   (2) interpretation target < expr
  2871   (3) interpret expr inst
  2872 
  2873 Interpretation in theories and proof contexts require a parameter
  2874 instantiation of terms from the current context.  This is applied to
  2875 specifications and theorems of the interpreted expression.
  2876 Interpretation in locales only permits parameter renaming through the
  2877 locale expression.  Interpretation is smart in that interpretations
  2878 that are active already do not occur in proof obligations, neither are
  2879 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2880 inspect active interpretations of a particular locale.  For details,
  2881 see the Isar Reference manual.  Examples can be found in
  2882 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2883 
  2884 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2885 'interpret' instead.
  2886 
  2887 * New context element 'constrains' for adding type constraints to
  2888 parameters.
  2889 
  2890 * Context expressions: renaming of parameters with syntax
  2891 redeclaration.
  2892 
  2893 * Locale declaration: 'includes' disallowed.
  2894 
  2895 * Proper static binding of attribute syntax -- i.e. types / terms /
  2896 facts mentioned as arguments are always those of the locale definition
  2897 context, independently of the context of later invocations.  Moreover,
  2898 locale operations (renaming and type / term instantiation) are applied
  2899 to attribute arguments as expected.
  2900 
  2901 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2902 actual attributes; rare situations may require Attrib.attribute to
  2903 embed those attributes into Attrib.src that lack concrete syntax.
  2904 Attribute implementations need to cooperate properly with the static
  2905 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2906 Attrib.XXX_thm etc. already do the right thing without further
  2907 intervention.  Only unusual applications -- such as "where" or "of"
  2908 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2909 on the context and the facts involved -- may have to assign parsed
  2910 values to argument tokens explicitly.
  2911 
  2912 * Changed parameter management in theorem generation for long goal
  2913 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2914 theorem statement in rare situations.
  2915 
  2916 * Locale inspection command 'print_locale' omits notes elements.  Use
  2917 'print_locale!' to have them included in the output.
  2918 
  2919 
  2920 *** Provers ***
  2921 
  2922 * Provers/hypsubst.ML: improved version of the subst method, for
  2923 single-step rewriting: it now works in bound variable contexts. New is
  2924 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2925 rewrite a different subterm than the original subst method, which is
  2926 still available as 'simplesubst'.
  2927 
  2928 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2929 and quasi orders.
  2930 
  2931 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2932 reflexive-transitive closure of relations.
  2933 
  2934 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2935 limit (previously hard-coded with a value of 20) user-definable.
  2936 
  2937 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  2938 is peformed already.  Object-logics merely need to finish their
  2939 initial simpset configuration as before.  INCOMPATIBILITY.
  2940 
  2941 
  2942 *** HOL ***
  2943 
  2944 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  2945 
  2946   syntax (epsilon)
  2947     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  2948 
  2949 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  2950 and x-symbol; use option '-m epsilon' to get it actually printed.
  2951 Moreover, the mathematically important symbolic identifier \<epsilon>
  2952 becomes available as variable, constant etc.  INCOMPATIBILITY,
  2953 
  2954 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  2955 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  2956 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  2957 support corresponding Isar calculations.
  2958 
  2959 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  2960 instead of ":".
  2961 
  2962 * theory SetInterval: changed the syntax for open intervals:
  2963 
  2964   Old       New
  2965   {..n(}    {..<n}
  2966   {)n..}    {n<..}
  2967   {m..n(}   {m..<n}
  2968   {)m..n}   {m<..n}
  2969   {)m..n(}  {m<..<n}
  2970 
  2971 The old syntax is still supported but will disappear in the next
  2972 release.  For conversion use the following Emacs search and replace
  2973 patterns (these are not perfect but work quite well):
  2974 
  2975   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  2976   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  2977 
  2978 * Theory Commutative_Ring (in Library): method comm_ring for proving
  2979 equalities in commutative rings; method 'algebra' provides a generic
  2980 interface.
  2981 
  2982 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  2983 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  2984 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  2985 be a tuple pattern.
  2986 
  2987 Some new syntax forms are available:
  2988 
  2989   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  2990   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  2991   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  2992   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  2993 
  2994 The latter form "\<Sum>x < k. e" used to be based on a separate
  2995 function "Summation", which has been discontinued.
  2996 
  2997 * theory Finite_Set: in structured induction proofs, the insert case
  2998 is now 'case (insert x F)' instead of the old counterintuitive 'case
  2999 (insert F x)'.
  3000 
  3001 * The 'refute' command has been extended to support a much larger
  3002 fragment of HOL, including axiomatic type classes, constdefs and
  3003 typedefs, inductive datatypes and recursion.
  3004 
  3005 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3006 Requires zChaff with proof generation to be installed.  See
  3007 HOL/ex/SAT_Examples.thy for examples.
  3008 
  3009 * Datatype induction via method 'induct' now preserves the name of the
  3010 induction variable. For example, when proving P(xs::'a list) by
  3011 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3012 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3013 in unstructured proof scripts.
  3014 
  3015 * Reworked implementation of records.  Improved scalability for
  3016 records with many fields, avoiding performance problems for type
  3017 inference. Records are no longer composed of nested field types, but
  3018 of nested extension types. Therefore the record type only grows linear
  3019 in the number of extensions and not in the number of fields.  The
  3020 top-level (users) view on records is preserved.  Potential
  3021 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3022 old record representation. The type generated for a record is called
  3023 <record_name>_ext_type.
  3024 
  3025 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3026 proofs triggered by a record definition or a simproc (if
  3027 quick_and_dirty is enabled).  Definitions of large records can take
  3028 quite long.
  3029 
  3030 New simproc record_upd_simproc for simplification of multiple record
  3031 updates enabled by default.  Moreover, trivial updates are also
  3032 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3033 occasionally, since simplification is more powerful by default.
  3034 
  3035 * typedef: proper support for polymorphic sets, which contain extra
  3036 type-variables in the term.
  3037 
  3038 * Simplifier: automatically reasons about transitivity chains
  3039 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3040 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3041 old proofs break occasionally as simplification may now solve more
  3042 goals than previously.
  3043 
  3044 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3045 present.  Works for all partial orders (class "order"), in particular
  3046 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3047 just like y <= x.
  3048 
  3049 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3050 bound variable or a constant then the let is unfolded.  Otherwise
  3051 first a is simplified to b, and then f b is simplified to g. If
  3052 possible we abstract b from g arriving at "let x = b in h x",
  3053 otherwise we unfold the let and arrive at g.  The simproc can be
  3054 enabled/disabled by the reference use_let_simproc.  Potential
  3055 INCOMPATIBILITY since simplification is more powerful by default.
  3056 
  3057 * Classical reasoning: the meson method now accepts theorems as arguments.
  3058 
  3059 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3060 jobs to provide advice on the provability of subgoals.
  3061 
  3062 * Theory OrderedGroup and Ring_and_Field: various additions and
  3063 improvements to faciliate calculations involving equalities and
  3064 inequalities.
  3065 
  3066 The following theorems have been eliminated or modified
  3067 (INCOMPATIBILITY):
  3068 
  3069   abs_eq             now named abs_of_nonneg
  3070   abs_of_ge_0        now named abs_of_nonneg
  3071   abs_minus_eq       now named abs_of_nonpos
  3072   imp_abs_id         now named abs_of_nonneg
  3073   imp_abs_neg_id     now named abs_of_nonpos
  3074   mult_pos           now named mult_pos_pos
  3075   mult_pos_le        now named mult_nonneg_nonneg
  3076   mult_pos_neg_le    now named mult_nonneg_nonpos
  3077   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3078   mult_neg           now named mult_neg_neg
  3079   mult_neg_le        now named mult_nonpos_nonpos
  3080 
  3081 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3082      
  3083      zero_le_square
  3084      not_square_less_zero 
  3085 
  3086   The following lemmas have been deleted from Real/RealPow:
  3087   
  3088      realpow_zero_zero
  3089      realpow_two
  3090      realpow_less
  3091      zero_le_power
  3092      realpow_two_le
  3093      abs_realpow_two
  3094      realpow_two_abs     
  3095 
  3096 * Theory Parity: added rules for simplifying exponents.
  3097 
  3098 * Theory List:
  3099 
  3100 The following theorems have been eliminated or modified
  3101 (INCOMPATIBILITY):
  3102 
  3103   list_all_Nil       now named list_all.simps(1)
  3104   list_all_Cons      now named list_all.simps(2)
  3105   list_all_conv      now named list_all_iff
  3106   set_mem_eq         now named mem_iff
  3107 
  3108 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3109 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3110 
  3111 
  3112 *** HOL-Complex ***
  3113 
  3114 * Theory RealDef: better support for embedding natural numbers and
  3115 integers in the reals.
  3116 
  3117 The following theorems have been eliminated or modified
  3118 (INCOMPATIBILITY):
  3119 
  3120   exp_ge_add_one_self  now requires no hypotheses
  3121   real_of_int_add      reversed direction of equality (use [symmetric])
  3122   real_of_int_minus    reversed direction of equality (use [symmetric])
  3123   real_of_int_diff     reversed direction of equality (use [symmetric])
  3124   real_of_int_mult     reversed direction of equality (use [symmetric])
  3125 
  3126 * Theory RComplete: expanded support for floor and ceiling functions.
  3127 
  3128 * Theory Ln is new, with properties of the natural logarithm
  3129 
  3130 * Hyperreal: There is a new type constructor "star" for making
  3131 nonstandard types.  The old type names are now type synonyms:
  3132 
  3133   hypreal = real star
  3134   hypnat = nat star
  3135   hcomplex = complex star
  3136 
  3137 * Hyperreal: Many groups of similarly-defined constants have been
  3138 replaced by polymorphic versions (INCOMPATIBILITY):
  3139 
  3140   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3141 
  3142   starset      <-- starsetNat, starsetC
  3143   *s*          <-- *sNat*, *sc*
  3144   starset_n    <-- starsetNat_n, starsetC_n
  3145   *sn*         <-- *sNatn*, *scn*
  3146   InternalSets <-- InternalNatSets, InternalCSets
  3147 
  3148   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3149   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3150   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3151   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3152   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3153 
  3154 * Hyperreal: Many type-specific theorems have been removed in favor of
  3155 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3156 
  3157   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3158   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3159   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3160   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3161   right_minus <-- hypreal_add_minus
  3162   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3163   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3164   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3165   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3166   mult_1_right <-- hcomplex_mult_one_right
  3167   mult_zero_left <-- hcomplex_mult_zero_left
  3168   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3169   right_distrib <-- hypnat_add_mult_distrib2
  3170   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3171   right_inverse <-- hypreal_mult_inverse
  3172   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3173   order_refl <-- {hypreal,hypnat}_le_refl
  3174   order_trans <-- {hypreal,hypnat}_le_trans
  3175   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3176   order_less_le <-- {hypreal,hypnat}_less_le
  3177   linorder_linear <-- {hypreal,hypnat}_le_linear
  3178   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3179   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3180   add_nonneg_nonneg <-- hypreal_le_add_order
  3181 
  3182 * Hyperreal: Separate theorems having to do with type-specific
  3183 versions of constants have been merged into theorems that apply to the
  3184 new polymorphic constants (INCOMPATIBILITY):
  3185 
  3186   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3187   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3188   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3189   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3190   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3191   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3192   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3193   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3194   STAR_diff <-- {STAR,STARC}_diff
  3195   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3196     STARC_hcomplex_of_complex}_image_subset
  3197   starset_n_Un <-- starset{Nat,C}_n_Un
  3198   starset_n_Int <-- starset{Nat,C}_n_Int
  3199   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3200   starset_n_diff <-- starset{Nat,C}_n_diff
  3201   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3202   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3203   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3204   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3205   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3206   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3207   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3208   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3209   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3210   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3211   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3212   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3213   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3214   starfun_diff <-- starfun{C,RC,CR}_diff
  3215   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3216   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3217   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3218   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3219   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3220   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3221   starfun_Id <-- starfunC_Id
  3222   starfun_approx <-- starfun{Nat,CR}_approx
  3223   starfun_capprox <-- starfun{C,RC}_capprox
  3224   starfun_abs <-- starfunNat_rabs
  3225   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3226   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3227   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3228   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3229   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3230   starfun_add_approx <-- starfunCR_add_approx
  3231   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3232   starfun_divide <-- starfun{C,CR,RC}_divide
  3233   starfun_n <-- starfun{Nat,C}_n
  3234   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3235   starfun_n_add <-- starfun{Nat,C}_n_add
  3236   starfun_n_add_minus <-- starfunNat_n_add_minus
  3237   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3238   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3239   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3240 
  3241   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3242   star_n_minus <-- {hypreal,hcomplex}_minus
  3243   star_n_diff <-- {hypreal,hcomplex}_diff
  3244   star_n_mult <-- {hypreal,hcomplex}_mult
  3245   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3246   star_n_le <-- {hypreal,hypnat}_le
  3247   star_n_less <-- {hypreal,hypnat}_less
  3248   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3249   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3250   star_n_abs <-- hypreal_hrabs
  3251   star_n_divide <-- hcomplex_divide
  3252 
  3253   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3254   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3255   star_of_diff <-- hypreal_of_real_diff
  3256   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3257   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3258   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3259   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3260   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3261   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3262   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3263   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3264   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3265   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3266   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3267   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3268   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3269   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3270   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3271   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3272   star_of_power <-- hypreal_of_real_power
  3273   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3274 
  3275 * Hyperreal: new method "transfer" that implements the transfer
  3276 principle of nonstandard analysis. With a subgoal that mentions
  3277 nonstandard types like "'a star", the command "apply transfer"
  3278 replaces it with an equivalent one that mentions only standard types.
  3279 To be successful, all free variables must have standard types; non-
  3280 standard variables must have explicit universal quantifiers.
  3281 
  3282 * Hyperreal: A theory of Taylor series.
  3283 
  3284 
  3285 *** HOLCF ***
  3286 
  3287 * Discontinued special version of 'constdefs' (which used to support
  3288 continuous functions) in favor of the general Pure one with full
  3289 type-inference.
  3290 
  3291 * New simplification procedure for solving continuity conditions; it
  3292 is much faster on terms with many nested lambda abstractions (cubic
  3293 instead of exponential time).
  3294 
  3295 * New syntax for domain package: selector names are now optional.
  3296 Parentheses should be omitted unless argument is lazy, for example:
  3297 
  3298   domain 'a stream = cons "'a" (lazy "'a stream")
  3299 
  3300 * New command 'fixrec' for defining recursive functions with pattern
  3301 matching; defining multiple functions with mutual recursion is also
  3302 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3303 sinr, or any data constructor defined by the domain package. The given
  3304 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3305 syntax and examples.
  3306 
  3307 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3308 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3309 but the proof obligation additionally includes an admissibility
  3310 requirement. The packages generate instances of class cpo or pcpo,
  3311 with continuity and strictness theorems for Rep and Abs.
  3312 
  3313 * HOLCF: Many theorems have been renamed according to a more standard naming
  3314 scheme (INCOMPATIBILITY):
  3315 
  3316   foo_inject:  "foo$x = foo$y ==> x = y"
  3317   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3318   foo_less:    "(foo$x << foo$y) = (x << y)"
  3319   foo_strict:  "foo$UU = UU"
  3320   foo_defined: "... ==> foo$x ~= UU"
  3321   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3322 
  3323 
  3324 *** ZF ***
  3325 
  3326 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3327 including the First Isomorphism Theorem (on quotienting by the kernel
  3328 of a homomorphism).
  3329 
  3330 * ZF/Simplifier: install second copy of type solver that actually
  3331 makes use of TC rules declared to Isar proof contexts (or locales);
  3332 the old version is still required for ML proof scripts.
  3333 
  3334 
  3335 *** Cube ***
  3336 
  3337 * Converted to Isar theory format; use locales instead of axiomatic
  3338 theories.
  3339 
  3340 
  3341 *** ML ***
  3342 
  3343 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3344 for ||>, ||>>, |>>,
  3345 
  3346 * Pure/library.ML no longer defines its own option datatype, but uses
  3347 that of the SML basis, which has constructors NONE and SOME instead of
  3348 None and Some, as well as exception Option.Option instead of OPTION.
  3349 The functions the, if_none, is_some, is_none have been adapted
  3350 accordingly, while Option.map replaces apsome.
  3351 
  3352 * Pure/library.ML: the exception LIST has been given up in favour of
  3353 the standard exceptions Empty and Subscript, as well as
  3354 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3355 superceded by the standard hd and tl functions etc.
  3356 
  3357 A number of basic list functions are no longer exported to the ML
  3358 toplevel, as they are variants of predefined functions.  The following
  3359 suggests how one can translate existing code:
  3360 
  3361     rev_append xs ys = List.revAppend (xs, ys)
  3362     nth_elem (i, xs) = List.nth (xs, i)
  3363     last_elem xs = List.last xs
  3364     flat xss = List.concat xss
  3365     seq fs = List.app fs
  3366     partition P xs = List.partition P xs
  3367     mapfilter f xs = List.mapPartial f xs
  3368 
  3369 * Pure/library.ML: several combinators for linear functional
  3370 transformations, notably reverse application and composition:
  3371 
  3372   x |> f                f #> g
  3373   (x, y) |-> f          f #-> g
  3374 
  3375 * Pure/library.ML: introduced/changed precedence of infix operators:
  3376 
  3377   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3378   infix 2 ?;
  3379   infix 3 o oo ooo oooo;
  3380   infix 4 ~~ upto downto;
  3381 
  3382 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3383 infix operators.
  3384 
  3385 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3386 fold_map support linear functional transformations and nesting.  For
  3387 example:
  3388 
  3389   fold f [x1, ..., xN] y =
  3390     y |> f x1 |> ... |> f xN
  3391 
  3392   (fold o fold) f [xs1, ..., xsN] y =
  3393     y |> fold f xs1 |> ... |> fold f xsN
  3394 
  3395   fold f [x1, ..., xN] =
  3396     f x1 #> ... #> f xN
  3397 
  3398   (fold o fold) f [xs1, ..., xsN] =
  3399     fold f xs1 #> ... #> fold f xsN
  3400 
  3401 * Pure/library.ML: the following selectors on type 'a option are
  3402 available:
  3403 
  3404   the:               'a option -> 'a  (*partial*)
  3405   these:             'a option -> 'a  where 'a = 'b list
  3406   the_default: 'a -> 'a option -> 'a
  3407   the_list:          'a option -> 'a list
  3408 
  3409 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3410 basic operations for association lists, following natural argument
  3411 order; moreover the explicit equality predicate passed here avoids
  3412 potentially expensive polymorphic runtime equality checks.
  3413 The old functions may be expressed as follows:
  3414 
  3415   assoc = uncurry (AList.lookup (op =))
  3416   assocs = these oo AList.lookup (op =)
  3417   overwrite = uncurry (AList.update (op =)) o swap
  3418 
  3419 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3420 
  3421   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3422   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3423 
  3424 replacing make_keylist and keyfilter (occassionally used)
  3425 Naive rewrites:
  3426 
  3427   make_keylist = AList.make
  3428   keyfilter = AList.find (op =)
  3429 
  3430 * eq_fst and eq_snd now take explicit equality parameter, thus
  3431   avoiding eqtypes. Naive rewrites:
  3432 
  3433     eq_fst = eq_fst (op =)
  3434     eq_snd = eq_snd (op =)
  3435 
  3436 * Removed deprecated apl and apr (rarely used).
  3437   Naive rewrites:
  3438 
  3439     apl (n, op) =>>= curry op n
  3440     apr (op, m) =>>= fn n => op (n, m)
  3441 
  3442 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3443 provides a reasonably efficient light-weight implementation of sets as
  3444 lists.
  3445 
  3446 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3447 few new operations; existing lookup and update are now curried to
  3448 follow natural argument order (for use with fold etc.);
  3449 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3450 
  3451 * Pure/General: output via the Isabelle channels of
  3452 writeln/warning/error etc. is now passed through Output.output, with a
  3453 hook for arbitrary transformations depending on the print_mode
  3454 (cf. Output.add_mode -- the first active mode that provides a output
  3455 function wins).  Already formatted output may be embedded into further
  3456 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3457 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3458 accommodate easy composition of diagnostic messages etc.  Programmers
  3459 rarely need to care about Output.output or Output.raw at all, with
  3460 some notable exceptions: Output.output is required when bypassing the
  3461 standard channels (writeln etc.), or in token translations to produce
  3462 properly formatted results; Output.raw is required when capturing
  3463 already output material that will eventually be presented to the user
  3464 a second time.  For the default print mode, both Output.output and
  3465 Output.raw have no effect.
  3466 
  3467 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3468 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3469 cumulative results are displayed at the end of a batch session.
  3470 
  3471 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3472 replaced by File.platform_path and File.shell_path (with appropriate
  3473 hooks).  This provides a clean interface for unusual systems where the
  3474 internal and external process view of file names are different.
  3475 
  3476 * Pure: more efficient orders for basic syntactic entities: added
  3477 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3478 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3479 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3480 orders now -- potential INCOMPATIBILITY for code that depends on a
  3481 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3482 Library.sort_strings on result).
  3483 
  3484 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3485 fold_types traverse types/terms from left to right, observing natural
  3486 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3487 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3488 
  3489 * Pure: name spaces have been refined, with significant changes of the
  3490 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3491 to extern(_table).  The plain name entry path is superceded by a
  3492 general 'naming' context, which also includes the 'policy' to produce
  3493 a fully qualified name and external accesses of a fully qualified
  3494 name; NameSpace.extend is superceded by context dependent
  3495 Sign.declare_name.  Several theory and proof context operations modify
  3496 the naming context.  Especially note Theory.restore_naming and
  3497 ProofContext.restore_naming to get back to a sane state; note that
  3498 Theory.add_path is no longer sufficient to recover from
  3499 Theory.absolute_path in particular.
  3500 
  3501 * Pure: new flags short_names (default false) and unique_names
  3502 (default true) for controlling output of qualified names.  If
  3503 short_names is set, names are printed unqualified.  If unique_names is
  3504 reset, the name prefix is reduced to the minimum required to achieve
  3505 the original result when interning again, even if there is an overlap
  3506 with earlier declarations.
  3507 
  3508 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3509 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3510 (useful for printing error messages).  INCOMPATIBILITY.
  3511 
  3512 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3513 Theory.theory are now identified, referring to the universal
  3514 Context.theory (see Pure/context.ML).  Actual signature and theory
  3515 content is managed as theory data.  The old code and interfaces were
  3516 spread over many files and structures; the new arrangement introduces
  3517 considerable INCOMPATIBILITY to gain more clarity:
  3518 
  3519   Context -- theory management operations (name, identity, inclusion,
  3520     parents, ancestors, merge, etc.), plus generic theory data;
  3521 
  3522   Sign -- logical signature and syntax operations (declaring consts,
  3523     types, etc.), plus certify/read for common entities;
  3524 
  3525   Theory -- logical theory operations (stating axioms, definitions,
  3526     oracles), plus a copy of logical signature operations (consts,
  3527     types, etc.); also a few basic management operations (Theory.copy,
  3528     Theory.merge, etc.)
  3529 
  3530 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3531 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3532 for convenience -- they merely return the theory.
  3533 
  3534 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3535 
  3536 * Pure: the Isar proof context type is already defined early in Pure
  3537 as Context.proof (note that ProofContext.context and Proof.context are
  3538 aliases, where the latter is the preferred name).  This enables other
  3539 Isabelle components to refer to that type even before Isar is present.
  3540 
  3541 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3542 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3543 any of these kinds.  For example, Sign.intern typeK is now
  3544 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3545 Theory.hide_types.  Also note that former
  3546 Theory.hide_classes/types/consts are now
  3547 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3548 internalize their arguments!  INCOMPATIBILITY.
  3549 
  3550 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3551 datatype thmref (with constructors Name and NameSelection) instead of
  3552 plain string -- INCOMPATIBILITY;
  3553 
  3554 * Pure: cases produced by proof methods specify options, where NONE
  3555 means to remove case bindings -- INCOMPATIBILITY in
  3556 (RAW_)METHOD_CASES.
  3557 
  3558 * Pure: the following operations retrieve axioms or theorems from a
  3559 theory node or theory hierarchy, respectively:
  3560 
  3561   Theory.axioms_of: theory -> (string * term) list
  3562   Theory.all_axioms_of: theory -> (string * term) list
  3563   PureThy.thms_of: theory -> (string * thm) list
  3564   PureThy.all_thms_of: theory -> (string * thm) list
  3565 
  3566 * Pure: print_tac now outputs the goal through the trace channel.
  3567 
  3568 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3569 Reference Toplevel.debug (default false) controls detailed printing
  3570 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3571 controls execution profiling -- set to 1 for time and 2 for space
  3572 (both increase the runtime).
  3573 
  3574 * Isar session: The initial use of ROOT.ML is now always timed,
  3575 i.e. the log will show the actual process times, in contrast to the
  3576 elapsed wall-clock time that the outer shell wrapper produces.
  3577 
  3578 * Simplifier: improved handling of bound variables (nameless
  3579 representation, avoid allocating new strings).  Simprocs that invoke
  3580 the Simplifier recursively should use Simplifier.inherit_bounds to
  3581 avoid local name clashes.  Failure to do so produces warnings
  3582 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3583 for further details.
  3584 
  3585 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3586 bindings for all theorems stored within a given theory; this may help
  3587 in porting non-Isar theories to Isar ones, while keeping ML proof
  3588 scripts for the time being.
  3589 
  3590 * ML operator HTML.with_charset specifies the charset begin used for
  3591 generated HTML files.  For example:
  3592 
  3593   HTML.with_charset "utf-8" use_thy "Hebrew";
  3594   HTML.with_charset "utf-8" use_thy "Chinese";
  3595 
  3596 
  3597 *** System ***
  3598 
  3599 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3600 isabelle, isatool etc.).
  3601 
  3602 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3603 isatool doc, isatool mkdir, display_drafts etc.).
  3604 
  3605 * isatool usedir: option -f allows specification of the ML file to be
  3606 used by Isabelle; default is ROOT.ML.
  3607 
  3608 * New isatool version outputs the version identifier of the Isabelle
  3609 distribution being used.
  3610 
  3611 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3612 (containing Boolean satisfiability problems) into Isabelle/HOL
  3613 theories.
  3614 
  3615 
  3616 
  3617 New in Isabelle2004 (April 2004)
  3618 --------------------------------
  3619 
  3620 *** General ***
  3621 
  3622 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3623   Replaces linorder.ML.
  3624 
  3625 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3626   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3627   (\<a>...\<z>), are now considered normal letters, and can therefore
  3628   be used anywhere where an ASCII letter (a...zA...Z) has until
  3629   now. COMPATIBILITY: This obviously changes the parsing of some
  3630   terms, especially where a symbol has been used as a binder, say
  3631   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3632   as an identifier.  Fix it by inserting a space around former
  3633   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3634   existing theory and ML files.
  3635 
  3636 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3637 
  3638 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3639   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3640   a normal (but invisible) letter. For multiple letter subscripts repeat
  3641   \<^isub> like this: x\<^isub>1\<^isub>2.
  3642 
  3643 * Pure: There are now sub-/superscripts that can span more than one
  3644   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3645   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3646   superscript. The new control characters are not identifier parts.
  3647 
  3648 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3649   content of "..." to the latex file instead of \isacntrl... . The "..."
  3650   may consist of any printable characters excluding the end bracket >.
  3651 
  3652 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3653   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3654   declare constants "final", which prevents their being given a definition
  3655   later.  It is useful for constants whose behaviour is fixed axiomatically
  3656   rather than definitionally, such as the meta-logic connectives.
  3657 
  3658 * Pure: 'instance' now handles general arities with general sorts
  3659   (i.e. intersections of classes),
  3660 
  3661 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3662   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3663   It can be changed to alter the colors/layout of generated pages.
  3664 
  3665 
  3666 *** Isar ***
  3667 
  3668 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3669   cut_tac, subgoal_tac and thin_tac:
  3670   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3671     locales are no longer forced to write Isar proof scripts.
  3672     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3673     emulations.
  3674   - INCOMPATIBILITY: names of variables to be instantiated may no
  3675     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3676     This is consistent with the instantiation attribute "where".
  3677 
  3678 * Attributes "where" and "of":
  3679   - Now take type variables of instantiated theorem into account when reading
  3680     the instantiation string.  This fixes a bug that caused instantiated
  3681     theorems to have too special types in some circumstances.
  3682   - "where" permits explicit instantiations of type variables.
  3683 
  3684 * Calculation commands "moreover" and "also" no longer interfere with
  3685   current facts ("this"), admitting arbitrary combinations with "then"
  3686   and derived forms.
  3687 
  3688 * Locales:
  3689   - Goal statements involving the context element "includes" no longer
  3690     generate theorems with internal delta predicates (those ending on
  3691     "_axioms") in the premise.
  3692     Resolve particular premise with <locale>.intro to obtain old form.
  3693   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3694     specification and "includes" elements in goal statement.
  3695   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3696     [intro?] and [elim?] (respectively) by default.
  3697   - Experimental command for instantiation of locales in proof contexts:
  3698         instantiate <label>[<attrs>]: <loc>
  3699     Instantiates locale <loc> and adds all its theorems to the current context
  3700     taking into account their attributes.  Label and attrs are optional
  3701     modifiers, like in theorem declarations.  If present, names of
  3702     instantiated theorems are qualified with <label>, and the attributes
  3703     <attrs> are applied after any attributes these theorems might have already.
  3704       If the locale has assumptions, a chained fact of the form
  3705     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3706     are derived.  The command does not support old-style locales declared
  3707     with "locale (open)".
  3708       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3709 
  3710 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3711   (Isar) contexts.
  3712 
  3713 
  3714 *** HOL ***
  3715 
  3716 * Proof import: new image HOL4 contains the imported library from
  3717   the HOL4 system with about 2500 theorems. It is imported by
  3718   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3719   can be used like any other Isabelle image.  See
  3720   HOL/Import/HOL/README for more information.
  3721 
  3722 * Simplifier:
  3723   - Much improved handling of linear and partial orders.
  3724     Reasoners for linear and partial orders are set up for type classes
  3725     "linorder" and "order" respectively, and are added to the default simpset
  3726     as solvers.  This means that the simplifier can build transitivity chains
  3727     to solve goals from the assumptions.
  3728   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3729     of blast or auto after simplification become unnecessary because the goal
  3730     is solved by simplification already.
  3731 
  3732 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3733     all proved in axiomatic type classes for semirings, rings and fields.
  3734 
  3735 * Numerics:
  3736   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3737     now formalized using the Ring_and_Field theory mentioned above.
  3738   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3739     than before, because now they are set up once in a generic manner.
  3740   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3741     Look for the general versions in Ring_and_Field (and Power if they concern
  3742     exponentiation).
  3743 
  3744 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3745 
  3746 * Records:
  3747   - Record types are now by default printed with their type abbreviation
  3748     instead of the list of all field types. This can be configured via
  3749     the reference "print_record_type_abbr".
  3750   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3751     (not enabled by default).
  3752   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3753     EX x. x = sel r to True (not enabled by default).
  3754   - Tactic "record_split_simp_tac" to split and simplify records added.
  3755 
  3756 * 'specification' command added, allowing for definition by
  3757   specification.  There is also an 'ax_specification' command that
  3758   introduces the new constants axiomatically.
  3759 
  3760 * arith(_tac) is now able to generate counterexamples for reals as well.
  3761 
  3762 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3763 
  3764 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3765   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3766 
  3767 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3768   matrix theory to linear programming.
  3769 
  3770 * Unions and Intersections:
  3771   The latex output syntax of UN and INT has been changed
  3772   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3773   i.e. the index formulae has become a subscript.
  3774   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3775 
  3776 * Unions and Intersections over Intervals:
  3777   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3778   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3779   like in normal math, and corresponding versions for < and for intersection.
  3780 
  3781 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3782   lexicographic dictonary ordering has been added as "lexord".
  3783 
  3784 * ML: the legacy theory structures Int and List have been removed. They had
  3785   conflicted with ML Basis Library structures having the same names.
  3786 
  3787 * 'refute' command added to search for (finite) countermodels.  Only works
  3788   for a fragment of HOL.  The installation of an external SAT solver is
  3789   highly recommended.  See "HOL/Refute.thy" for details.
  3790 
  3791 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3792   formulae under an assignment of free variables to random values.
  3793   In contrast to 'refute', it can deal with inductive datatypes,
  3794   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3795   for examples.
  3796 
  3797 
  3798 *** HOLCF ***
  3799 
  3800 * Streams now come with concatenation and are part of the HOLCF image
  3801 
  3802 
  3803 
  3804 New in Isabelle2003 (May 2003)
  3805 ------------------------------
  3806 
  3807 *** General ***
  3808 
  3809 * Provers/simplifier:
  3810 
  3811   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3812     Assumptions are now subject to complete mutual simplification,
  3813     not just from left to right. The simplifier now preserves
  3814     the order of assumptions.
  3815 
  3816     Potential INCOMPATIBILITY:
  3817 
  3818     -- simp sometimes diverges where the old version did
  3819        not, e.g. invoking simp on the goal
  3820 
  3821         [| P (f x); y = x; f x = f y |] ==> Q
  3822 
  3823        now gives rise to the infinite reduction sequence
  3824 
  3825         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3826 
  3827        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3828        kind of problem.
  3829 
  3830     -- Tactics combining classical reasoner and simplification (such as auto)
  3831        are also affected by this change, because many of them rely on
  3832        simp. They may sometimes diverge as well or yield a different numbers
  3833        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3834        in case of problems. Sometimes subsequent calls to the classical
  3835        reasoner will fail because a preceeding call to the simplifier too
  3836        eagerly simplified the goal, e.g. deleted redundant premises.
  3837 
  3838   - The simplifier trace now shows the names of the applied rewrite rules
  3839 
  3840   - You can limit the number of recursive invocations of the simplifier
  3841     during conditional rewriting (where the simplifie tries to solve the
  3842     conditions before applying the rewrite rule):
  3843     ML "simp_depth_limit := n"
  3844     where n is an integer. Thus you can force termination where previously
  3845     the simplifier would diverge.
  3846 
  3847   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3848 
  3849   - No longer aborts on failed congruence proof.  Instead, the
  3850     congruence is ignored.
  3851 
  3852 * Pure: New generic framework for extracting programs from constructive
  3853   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3854   as HOL/Extraction for some case studies.
  3855 
  3856 * Pure: The main goal of the proof state is no longer shown by default, only
  3857 the subgoals. This behaviour is controlled by a new flag.
  3858    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3859 (ML: Proof.show_main_goal).
  3860 
  3861 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3862 rules whose conclusion matches subgoal 1:
  3863       PG menu: Isabelle/Isar -> Show me -> matching rules
  3864 The rules are ordered by how closely they match the subgoal.
  3865 In particular, rules that solve a subgoal outright are displayed first
  3866 (or rather last, the way they are printed).
  3867 (ML: ProofGeneral.print_intros())
  3868 
  3869 * Pure: New flag trace_unify_fail causes unification to print
  3870 diagnostic information (PG: in trace buffer) when it fails. This is
  3871 useful for figuring out why single step proofs like rule, erule or
  3872 assumption failed.
  3873 
  3874 * Pure: Locale specifications now produce predicate definitions
  3875 according to the body of text (covering assumptions modulo local
  3876 definitions); predicate "loc_axioms" covers newly introduced text,
  3877 while "loc" is cumulative wrt. all included locale expressions; the
  3878 latter view is presented only on export into the global theory
  3879 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3880 on the old view without predicates;
  3881 
  3882 * Pure: predefined locales "var" and "struct" are useful for sharing
  3883 parameters (as in CASL, for example); just specify something like
  3884 ``var x + var y + struct M'' as import;
  3885 
  3886 * Pure: improved thms_containing: proper indexing of facts instead of
  3887 raw theorems; check validity of results wrt. current name space;
  3888 include local facts of proof configuration (also covers active
  3889 locales), cover fixed variables in index; may use "_" in term
  3890 specification; an optional limit for the number of printed facts may
  3891 be given (the default is 40);
  3892 
  3893 * Pure: disallow duplicate fact bindings within new-style theory files
  3894 (batch-mode only);
  3895 
  3896 * Provers: improved induct method: assumptions introduced by case
  3897 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3898 the goal statement); "foo" still refers to all facts collectively;
  3899 
  3900 * Provers: the function blast.overloaded has been removed: all constants
  3901 are regarded as potentially overloaded, which improves robustness in exchange
  3902 for slight decrease in efficiency;
  3903 
  3904 * Provers/linorder: New generic prover for transitivity reasoning over
  3905 linear orders.  Note: this prover is not efficient!
  3906 
  3907 * Isar: preview of problems to finish 'show' now produce an error
  3908 rather than just a warning (in interactive mode);
  3909 
  3910 
  3911 *** HOL ***
  3912 
  3913 * arith(_tac)
  3914 
  3915  - Produces a counter example if it cannot prove a goal.
  3916    Note that the counter example may be spurious if the goal is not a formula
  3917    of quantifier-free linear arithmetic.
  3918    In ProofGeneral the counter example appears in the trace buffer.
  3919 
  3920  - Knows about div k and mod k where k is a numeral of type nat or int.
  3921 
  3922  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3923    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3924    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3925 
  3926 * simp's arithmetic capabilities have been enhanced a bit: it now
  3927 takes ~= in premises into account (by performing a case split);
  3928 
  3929 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3930 are distributed over a sum of terms;
  3931 
  3932 * New tactic "trans_tac" and method "trans" instantiate
  3933 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3934 "<=", "<" and "=").
  3935 
  3936 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3937 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  3938 
  3939 * 'typedef' command has new option "open" to suppress the set
  3940 definition;
  3941 
  3942 * functions Min and Max on finite sets have been introduced (theory
  3943 Finite_Set);
  3944 
  3945 * attribute [symmetric] now works for relations as well; it turns
  3946 (x,y) : R^-1 into (y,x) : R, and vice versa;
  3947 
  3948 * induct over a !!-quantified statement (say !!x1..xn):
  3949   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  3950 
  3951 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  3952 %x. None. Warning: empty_def now refers to the previously hidden definition
  3953 of the empty set.
  3954 
  3955 * Algebra: formalization of classical algebra.  Intended as base for
  3956 any algebraic development in Isabelle.  Currently covers group theory
  3957 (up to Sylow's theorem) and ring theory (Universal Property of
  3958 Univariate Polynomials).  Contributions welcome;
  3959 
  3960 * GroupTheory: deleted, since its material has been moved to Algebra;
  3961 
  3962 * Complex: new directory of the complex numbers with numeric constants,
  3963 nonstandard complex numbers, and some complex analysis, standard and
  3964 nonstandard (Jacques Fleuriot);
  3965 
  3966 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  3967 
  3968 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  3969 Fleuriot);
  3970 
  3971 * Real/HahnBanach: updated and adapted to locales;
  3972 
  3973 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  3974 Gray and Kramer);
  3975 
  3976 * UNITY: added the Meier-Sanders theory of progress sets;
  3977 
  3978 * MicroJava: bytecode verifier and lightweight bytecode verifier
  3979 as abstract algorithms, instantiated to the JVM;
  3980 
  3981 * Bali: Java source language formalization. Type system, operational
  3982 semantics, axiomatic semantics. Supported language features:
  3983 classes, interfaces, objects,virtual methods, static methods,
  3984 static/instance fields, arrays, access modifiers, definite
  3985 assignment, exceptions.
  3986 
  3987 
  3988 *** ZF ***
  3989 
  3990 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  3991 universe, etc.);
  3992 
  3993 * Main ZF: virtually all theories converted to new-style format;
  3994 
  3995 
  3996 *** ML ***
  3997 
  3998 * Pure: Tactic.prove provides sane interface for internal proofs;
  3999 omits the infamous "standard" operation, so this is more appropriate
  4000 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4001 
  4002 * Pure: improved error reporting of simprocs;
  4003 
  4004 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4005 up simprocs;
  4006 
  4007 
  4008 *** Document preparation ***
  4009 
  4010 * uses \par instead of \\ for line breaks in theory text. This may
  4011 shift some page breaks in large documents. To get the old behaviour
  4012 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4013 
  4014 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4015 other packages
  4016 
  4017 * \<euro> now needs package babel/greek instead of marvosym (which
  4018 broke \Rightarrow)
  4019 
  4020 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4021 textcomp package)
  4022 
  4023 
  4024 
  4025 New in Isabelle2002 (March 2002)
  4026 --------------------------------
  4027 
  4028 *** Document preparation ***
  4029 
  4030 * greatly simplified document preparation setup, including more
  4031 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4032 instructive isatool mkdir; users should basically be able to get
  4033 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4034 users may run a separate document processing stage manually like this:
  4035 "isatool usedir -D output HOL Test && isatool document Test/output";
  4036 
  4037 * theory dependency graph may now be incorporated into documents;
  4038 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4039 with \includegraphics of LaTeX;
  4040 
  4041 * proper spacing of consecutive markup elements, especially text
  4042 blocks after section headings;
  4043 
  4044 * support bold style (for single symbols only), input syntax is like
  4045 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4046 
  4047 * \<bullet> is now output as bold \cdot by default, which looks much
  4048 better in printed text;
  4049 
  4050 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4051 note that these symbols are currently unavailable in Proof General /
  4052 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4053 
  4054 * isatool latex no longer depends on changed TEXINPUTS, instead
  4055 isatool document copies the Isabelle style files to the target
  4056 location;
  4057 
  4058 
  4059 *** Isar ***
  4060 
  4061 * Pure/Provers: improved proof by cases and induction;
  4062   - 'case' command admits impromptu naming of parameters (such as
  4063     "case (Suc n)");
  4064   - 'induct' method divinates rule instantiation from the inductive
  4065     claim; no longer requires excessive ?P bindings for proper
  4066     instantiation of cases;
  4067   - 'induct' method properly enumerates all possibilities of set/type
  4068     rules; as a consequence facts may be also passed through *type*
  4069     rules without further ado;
  4070   - 'induct' method now derives symbolic cases from the *rulified*
  4071     rule (before it used to rulify cases stemming from the internal
  4072     atomized version); this means that the context of a non-atomic
  4073     statement becomes is included in the hypothesis, avoiding the
  4074     slightly cumbersome show "PROP ?case" form;
  4075   - 'induct' may now use elim-style induction rules without chaining
  4076     facts, using ``missing'' premises from the goal state; this allows
  4077     rules stemming from inductive sets to be applied in unstructured
  4078     scripts, while still benefitting from proper handling of non-atomic
  4079     statements; NB: major inductive premises need to be put first, all
  4080     the rest of the goal is passed through the induction;
  4081   - 'induct' proper support for mutual induction involving non-atomic
  4082     rule statements (uses the new concept of simultaneous goals, see
  4083     below);
  4084   - append all possible rule selections, but only use the first
  4085     success (no backtracking);
  4086   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4087   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4088   - added 'print_induct_rules' (covered by help item in recent Proof
  4089     General versions);
  4090   - moved induct/cases attributes to Pure, methods to Provers;
  4091   - generic method setup instantiated for FOL and HOL;
  4092 
  4093 * Pure: support multiple simultaneous goal statements, for example
  4094 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4095 meta-level mechanism, this acts as if several individual goals had
  4096 been stated separately; in particular common proof methods need to be
  4097 repeated in order to cover all claims; note that a single elimination
  4098 step is *not* sufficient to establish the two conjunctions, so this
  4099 fails:
  4100 
  4101   assume "A & B" then have A and B ..   (*".." fails*)
  4102 
  4103 better use "obtain" in situations as above; alternative refer to
  4104 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4105 
  4106 * Pure: proper integration with ``locales''; unlike the original
  4107 version by Florian Kammller, Isar locales package high-level proof
  4108 contexts rather than raw logical ones (e.g. we admit to include
  4109 attributes everywhere); operations on locales include merge and
  4110 rename; support for implicit arguments (``structures''); simultaneous
  4111 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4112 some examples;
  4113 
  4114 * Pure: the following commands have been ``localized'', supporting a
  4115 target locale specification "(in name)": 'lemma', 'theorem',
  4116 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4117 stored both within the locale and at the theory level (exported and
  4118 qualified by the locale name);
  4119 
  4120 * Pure: theory goals may now be specified in ``long'' form, with
  4121 ad-hoc contexts consisting of arbitrary locale elements. for example
  4122 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4123 definitions may be given, too); the result is a meta-level rule with
  4124 the context elements being discharged in the obvious way;
  4125 
  4126 * Pure: new proof command 'using' allows to augment currently used
  4127 facts after a goal statement ('using' is syntactically analogous to
  4128 'apply', but acts on the goal's facts only); this allows chained facts
  4129 to be separated into parts given before and after a claim, as in
  4130 ``from a and b have C using d and e <proof>'';
  4131 
  4132 * Pure: renamed "antecedent" case to "rule_context";
  4133 
  4134 * Pure: new 'judgment' command records explicit information about the
  4135 object-logic embedding (used by several tools internally); no longer
  4136 use hard-wired "Trueprop";
  4137 
  4138 * Pure: added 'corollary' command;
  4139 
  4140 * Pure: fixed 'token_translation' command;
  4141 
  4142 * Pure: removed obsolete 'exported' attribute;
  4143 
  4144 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4145 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4146 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4147 
  4148 * Pure: method 'atomize' presents local goal premises as object-level
  4149 statements (atomic meta-level propositions); setup controlled via
  4150 rewrite rules declarations of 'atomize' attribute; example
  4151 application: 'induct' method with proper rule statements in improper
  4152 proof *scripts*;
  4153 
  4154 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4155 now consider the syntactic context of assumptions, giving a better
  4156 chance to get type-inference of the arguments right (this is
  4157 especially important for locales);
  4158 
  4159 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4160 mode;
  4161 
  4162 * Pure/obtain: the formal conclusion "thesis", being marked as
  4163 ``internal'', may no longer be reference directly in the text;
  4164 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4165 situations;
  4166 
  4167 * Pure: generic 'sym' attribute which declares a rule both as pure
  4168 'elim?' and for the 'symmetric' operation;
  4169 
  4170 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4171 text; the fixed correlation with particular command syntax has been
  4172 discontinued;
  4173 
  4174 * Pure: new method 'rules' is particularly well-suited for proof
  4175 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4176 but often produces more compact proof terms with less detours;
  4177 
  4178 * Pure/Provers/classical: simplified integration with pure rule
  4179 attributes and methods; the classical "intro?/elim?/dest?"
  4180 declarations coincide with the pure ones; the "rule" method no longer
  4181 includes classically swapped intros; "intro" and "elim" methods no
  4182 longer pick rules from the context; also got rid of ML declarations
  4183 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4184 INCOMPATIBILITY;
  4185 
  4186 * Provers/classical: attribute 'swapped' produces classical inversions
  4187 of introduction rules;
  4188 
  4189 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4190 rules instead of full simplifier context; 'iff' attribute handles
  4191 conditional rules;
  4192 
  4193 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4194 
  4195 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4196 "(permissive)" option to recover old behavior;
  4197 
  4198 * HOL: 'inductive' no longer features separate (collective) attributes
  4199 for 'intros' (was found too confusing);
  4200 
  4201 * HOL: properly declared induction rules less_induct and
  4202 wf_induct_rule;
  4203 
  4204 
  4205 *** HOL ***
  4206 
  4207 * HOL: moved over to sane numeral syntax; the new policy is as
  4208 follows:
  4209 
  4210   - 0 and 1 are polymorphic constants, which are defined on any
  4211   numeric type (nat, int, real etc.);
  4212 
  4213   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4214   binary representation internally;
  4215 
  4216   - type nat has special constructor Suc, and generally prefers Suc 0
  4217   over 1::nat and Suc (Suc 0) over 2::nat;
  4218 
  4219 This change may cause significant problems of INCOMPATIBILITY; here
  4220 are some hints on converting existing sources:
  4221 
  4222   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4223   entities, so expressions involving "-" (unary or binary minus) need
  4224   to be spaced properly;
  4225 
  4226   - existing occurrences of "1" may need to be constraint "1::nat" or
  4227   even replaced by Suc 0; similar for old "2";
  4228 
  4229   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4230 
  4231   - remove all special provisions on numerals in proofs;
  4232 
  4233 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4234 representation (depends on bin_arith_simps in the default context);
  4235 
  4236 * HOL: symbolic syntax for x^2 (numeral 2);
  4237 
  4238 * HOL: the class of all HOL types is now called "type" rather than
  4239 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4240 in axclass/classes, instance/arities, and (usually rare) occurrences
  4241 in typings (of consts etc.); internally the class is called
  4242 "HOL.type", ML programs should refer to HOLogic.typeS;
  4243 
  4244 * HOL/record package improvements:
  4245   - new derived operations "fields" to build a partial record section,
  4246     "extend" to promote a fixed record to a record scheme, and
  4247     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4248     declared as simp by default;
  4249   - shared operations ("more", "fields", etc.) now need to be always
  4250     qualified) --- potential INCOMPATIBILITY;
  4251   - removed "make_scheme" operations (use "make" with "extend") --
  4252     INCOMPATIBILITY;
  4253   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4254   - provides cases/induct rules for use with corresponding Isar
  4255     methods (for concrete records, record schemes, concrete more
  4256     parts, and schematic more parts -- in that order);
  4257   - internal definitions directly based on a light-weight abstract
  4258     theory of product types over typedef rather than datatype;
  4259 
  4260 * HOL: generic code generator for generating executable ML code from
  4261 specifications; specific support for HOL constructs such as inductive
  4262 datatypes and sets, as well as recursive functions; can be invoked
  4263 via 'generate_code' theory section;
  4264 
  4265 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4266 
  4267 * HOL: consolidated and renamed several theories.  In particular:
  4268         Ord.thy has been absorbed into HOL.thy
  4269         String.thy has been absorbed into List.thy
  4270 
  4271 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4272 (beware of argument permutation!);
  4273 
  4274 * HOL: linorder_less_split superseded by linorder_cases;
  4275 
  4276 * HOL/List: "nodups" renamed to "distinct";
  4277 
  4278 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4279 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4280   - Ex_def has changed, now need to use some_eq_ex
  4281 
  4282 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4283 in this (rare) case use:
  4284 
  4285   delSWrapper "split_all_tac"
  4286   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4287 
  4288 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4289 MAY FAIL;
  4290 
  4291 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4292 Isabelle's type classes, ^ on functions and relations has too general
  4293 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4294 necessary to attach explicit type constraints;
  4295 
  4296 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4297 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4298 renamed accordingly (eg "compI" -> "rel_compI").
  4299 
  4300 * HOL: syntax translations now work properly with numerals and records
  4301 expressions;
  4302 
  4303 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4304 of "lam" -- INCOMPATIBILITY;
  4305 
  4306 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4307 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4308 renamed "Product_Type.unit";
  4309 
  4310 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4311 
  4312 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4313 the "cases" method);
  4314 
  4315 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4316 Florian Kammller);
  4317 
  4318 * HOL/IMP: updated and converted to new-style theory format; several
  4319 parts turned into readable document, with proper Isar proof texts and
  4320 some explanations (by Gerwin Klein);
  4321 
  4322 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4323 
  4324 * HOL-Hyperreal is now a logic image;
  4325 
  4326 
  4327 *** HOLCF ***
  4328 
  4329 * Isar: consts/constdefs supports mixfix syntax for continuous
  4330 operations;
  4331 
  4332 * Isar: domain package adapted to new-style theory format, e.g. see
  4333 HOLCF/ex/Dnat.thy;
  4334 
  4335 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4336 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4337 lift.induct_tac, always use UU instead of Undef;
  4338 
  4339 * HOLCF/IMP: updated and converted to new-style theory;
  4340 
  4341 
  4342 *** ZF ***
  4343 
  4344 * Isar: proper integration of logic-specific tools and packages,
  4345 including theory commands '(co)inductive', '(co)datatype',
  4346 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4347 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4348 
  4349 * theory Main no longer includes AC; for the Axiom of Choice, base
  4350 your theory on Main_ZFC;
  4351 
  4352 * the integer library now covers quotients and remainders, with many
  4353 laws relating division to addition, multiplication, etc.;
  4354 
  4355 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4356 typeless version of the formalism;
  4357 
  4358 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4359 format;
  4360 
  4361 * ZF/Induct: new directory for examples of inductive definitions,
  4362 including theory Multiset for multiset orderings; converted to
  4363 new-style theory format;
  4364 
  4365 * ZF: many new theorems about lists, ordinals, etc.;
  4366 
  4367 
  4368 *** General ***
  4369 
  4370 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4371 variable proof controls level of detail: 0 = no proofs (only oracle
  4372 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4373 also ref manual for further ML interfaces;
  4374 
  4375 * Pure/axclass: removed obsolete ML interface
  4376 goal_subclass/goal_arity;
  4377 
  4378 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4379 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4380 separate tokens, so expressions involving minus need to be spaced
  4381 properly;
  4382 
  4383 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4384 rather than "infixl" or "infixr";
  4385 
  4386 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4387 sort constraint specifications in type inference; e.g. "x::_::foo"
  4388 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4389 type variable);
  4390 
  4391 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4392 control output of nested => (types); the default behavior is
  4393 "type_brackets";
  4394 
  4395 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4396 tokens into AST constants;
  4397 
  4398 * Pure/syntax: prefer later declarations of translations and print
  4399 translation functions; potential INCOMPATIBILITY: need to reverse
  4400 multiple declarations for same syntax element constant;
  4401 
  4402 * Pure/show_hyps reset by default (in accordance to existing Isar
  4403 practice);
  4404 
  4405 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4406 addSafter;
  4407 
  4408 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4409 as well;
  4410 
  4411 * system: tested support for MacOS X; should be able to get Isabelle +
  4412 Proof General to work in a plain Terminal after installing Poly/ML
  4413 (e.g. from the Isabelle distribution area) and GNU bash alone
  4414 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4415 support requires further installations, e.g. from
  4416 http://fink.sourceforge.net/);
  4417 
  4418 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4419 
  4420 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4421 of 40 MB), cf. ML_OPTIONS;
  4422 
  4423 * system: Proof General keywords specification is now part of the
  4424 Isabelle distribution (see etc/isar-keywords.el);
  4425 
  4426 * system: support for persistent Proof General sessions (refrain from
  4427 outdating all loaded theories on startup); user may create writable
  4428 logic images like this: ``isabelle -q HOL Test'';
  4429 
  4430 * system: smart selection of Isabelle process versus Isabelle
  4431 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4432 run both "isabelle" and "Isabelle" even if file names are badly
  4433 damaged (executable inspects the case of the first letter of its own
  4434 name); added separate "isabelle-process" and "isabelle-interface";
  4435 
  4436 * system: refrain from any attempt at filtering input streams; no
  4437 longer support ``8bit'' encoding of old isabelle font, instead proper
  4438 iso-latin characters may now be used; the related isatools
  4439 "symbolinput" and "nonascii" have disappeared as well;
  4440 
  4441 * system: removed old "xterm" interface (the print modes "xterm" and
  4442 "xterm_color" are still available for direct use in a suitable
  4443 terminal);
  4444 
  4445 
  4446 
  4447 New in Isabelle99-2 (February 2001)
  4448 -----------------------------------
  4449 
  4450 *** Overview of INCOMPATIBILITIES ***
  4451 
  4452 * HOL: please note that theories in the Library and elsewhere often use the
  4453 new-style (Isar) format; to refer to their theorems in an ML script you must
  4454 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4455 
  4456 * HOL: inductive package no longer splits induction rule aggressively,
  4457 but only as far as specified by the introductions given; the old
  4458 format may be recovered via ML function complete_split_rule or attribute
  4459 'split_rule (complete)';
  4460 
  4461 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4462 gfp_Tarski to gfp_unfold;
  4463 
  4464 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4465 
  4466 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4467 relation); infix "^^" has been renamed "``"; infix "``" has been
  4468 renamed "`"; "univalent" has been renamed "single_valued";
  4469 
  4470 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4471 operation;
  4472 
  4473 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4474 
  4475 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4476 
  4477 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4478 consequence, it is no longer monotonic wrt. the local goal context
  4479 (which is now passed through the inductive cases);
  4480 
  4481 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4482 \<gg> to \<ggreater>;
  4483 
  4484 
  4485 *** Document preparation ***
  4486 
  4487 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4488 available: are "it" for near math-mode best-style output, "sl" for
  4489 slanted text style, and "tt" for plain type-writer; if no
  4490 \isabellestyle command is given, output is according to slanted
  4491 type-writer);
  4492 
  4493 * support sub/super scripts (for single symbols only), input syntax is
  4494 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4495 
  4496 * some more standard symbols; see Appendix A of the system manual for
  4497 the complete list of symbols defined in isabellesym.sty;
  4498 
  4499 * improved isabelle style files; more abstract symbol implementation
  4500 (should now use \isamath{...} and \isatext{...} in custom symbol
  4501 definitions);
  4502 
  4503 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4504 state; Note that presentation of goal states does not conform to
  4505 actual human-readable proof documents.  Please do not include goal
  4506 states into document output unless you really know what you are doing!
  4507 
  4508 * proper indentation of antiquoted output with proportional LaTeX
  4509 fonts;
  4510 
  4511 * no_document ML operator temporarily disables LaTeX document
  4512 generation;
  4513 
  4514 * isatool unsymbolize tunes sources for plain ASCII communication;
  4515 
  4516 
  4517 *** Isar ***
  4518 
  4519 * Pure: Isar now suffers initial goal statements to contain unbound
  4520 schematic variables (this does not conform to actual readable proof
  4521 documents, due to unpredictable outcome and non-compositional proof
  4522 checking); users who know what they are doing may use schematic goals
  4523 for Prolog-style synthesis of proven results;
  4524 
  4525 * Pure: assumption method (an implicit finishing) now handles actual
  4526 rules as well;
  4527 
  4528 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4529 initial goal, declare "that" only as Pure intro (only for single
  4530 steps); the "that" rule assumption may now be involved in implicit
  4531 finishing, thus ".." becomes a feasible for trivial obtains;
  4532 
  4533 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4534 instance proofs may be performed by "..";
  4535 
  4536 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4537 statements as well;
  4538 
  4539 * Pure: more robust selection of calculational rules;
  4540 
  4541 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4542 rule (as well as the assumption rule);
  4543 
  4544 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4545 lemmas, using the graph browser tool;
  4546 
  4547 * Pure: predict failure of "show" in interactive mode;
  4548 
  4549 * Pure: 'thms_containing' now takes actual terms as arguments;
  4550 
  4551 * HOL: improved method 'induct' --- now handles non-atomic goals
  4552 (potential INCOMPATIBILITY); tuned error handling;
  4553 
  4554 * HOL: cases and induct rules now provide explicit hints about the
  4555 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4556 any remaining facts are inserted into the goal verbatim;
  4557 
  4558 * HOL: local contexts (aka cases) may now contain term bindings as
  4559 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4560 the result to be shown in each case;
  4561 
  4562 * HOL: added 'recdef_tc' command;
  4563 
  4564 * isatool convert assists in eliminating legacy ML scripts;
  4565 
  4566 
  4567 *** HOL ***
  4568 
  4569 * HOL/Library: a collection of generic theories to be used together
  4570 with main HOL; the theory loader path already includes this directory
  4571 by default; the following existing theories have been moved here:
  4572 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4573 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4574 
  4575 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4576 modelling and verification task performed in Isabelle/HOL +
  4577 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4578 
  4579 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4580 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4581 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4582 'domain', this makes the theory consistent with mathematical
  4583 literature;
  4584 
  4585 * HOL basics: added overloaded operations "inverse" and "divide"
  4586 (infix "/"), syntax for generic "abs" operation, generic summation
  4587 operator \<Sum>;
  4588 
  4589 * HOL/typedef: simplified package, provide more useful rules (see also
  4590 HOL/subset.thy);
  4591 
  4592 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4593 now expressed as a proper nested rule (old-style tactic scripts may
  4594 require atomize_strip_tac to cope with non-atomic premises);
  4595 
  4596 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4597 to "split_conv" (old name still available for compatibility);
  4598 
  4599 * HOL: improved concrete syntax for strings (e.g. allows translation
  4600 rules with string literals);
  4601 
  4602 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4603  and Fleuriot's mechanization of analysis, including the transcendental
  4604  functions for the reals;
  4605 
  4606 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4607 
  4608 
  4609 *** CTT ***
  4610 
  4611 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4612 "lam" is displayed as TWO lambda-symbols
  4613 
  4614 * CTT: theory Main now available, containing everything (that is, Bool
  4615 and Arith);
  4616 
  4617 
  4618 *** General ***
  4619 
  4620 * Pure: the Simplifier has been implemented properly as a derived rule
  4621 outside of the actual kernel (at last!); the overall performance
  4622 penalty in practical applications is about 50%, while reliability of
  4623 the Isabelle inference kernel has been greatly improved;
  4624 
  4625 * print modes "brackets" and "no_brackets" control output of nested =>
  4626 (types) and ==> (props); the default behaviour is "brackets";
  4627 
  4628 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4629 as assumptions as well;
  4630 
  4631 * system: support Poly/ML 4.0;
  4632 
  4633 * system: isatool install handles KDE version 1 or 2;
  4634 
  4635 
  4636 
  4637 New in Isabelle99-1 (October 2000)
  4638 ----------------------------------
  4639 
  4640 *** Overview of INCOMPATIBILITIES ***
  4641 
  4642 * HOL: simplification of natural numbers is much changed; to partly
  4643 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4644 issue the following ML commands:
  4645 
  4646   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4647   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4648 
  4649 * HOL: simplification no longer dives into case-expressions; this is
  4650 controlled by "t.weak_case_cong" for each datatype t;
  4651 
  4652 * HOL: nat_less_induct renamed to less_induct;
  4653 
  4654 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4655 fixsome to patch .thy and .ML sources automatically;
  4656 
  4657   select_equality  -> some_equality
  4658   select_eq_Ex     -> some_eq_ex
  4659   selectI2EX       -> someI2_ex
  4660   selectI2         -> someI2
  4661   selectI          -> someI
  4662   select1_equality -> some1_equality
  4663   Eps_sym_eq       -> some_sym_eq_trivial
  4664   Eps_eq           -> some_eq_trivial
  4665 
  4666 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4667 
  4668 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4669 instead);
  4670 
  4671 * HOL: the recursion equations generated by 'recdef' are now called
  4672 f.simps instead of f.rules;
  4673 
  4674 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4675 
  4676 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4677 sometimes be needed;
  4678 
  4679 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4680 
  4681 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4682 
  4683 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4684 product is now "<*>" instead of "Times"; the lexicographic product is
  4685 now "<*lex*>" instead of "**";
  4686 
  4687 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4688 of main HOL, but was unused); better use HOL's datatype package;
  4689 
  4690 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4691 the old syntax may be recovered as follows:
  4692 
  4693   syntax (symbols)
  4694     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4695       (infixl "\\<oplus>" 100)
  4696 
  4697 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4698 
  4699 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4700 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4701 internally;
  4702 
  4703 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4704 changed from A/r to A//r;
  4705 
  4706 * ZF: new treatment of arithmetic (nat & int) may break some old
  4707 proofs;
  4708 
  4709 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4710 rulify -> rule_format, elimify -> elim_format, ...);
  4711 
  4712 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4713 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4714 should have to change intro!! to intro? only); replaced "delrule" by
  4715 "rule del";
  4716 
  4717 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4718 
  4719 * Provers: strengthened force_tac by using new first_best_tac;
  4720 
  4721 * LaTeX document preparation: several changes of isabelle.sty (see
  4722 lib/texinputs);
  4723 
  4724 
  4725 *** Document preparation ***
  4726 
  4727 * formal comments (text blocks etc.) in new-style theories may now
  4728 contain antiquotations of thm/prop/term/typ/text to be presented
  4729 according to latex print mode; concrete syntax is like this:
  4730 @{term[show_types] "f(x) = a + x"};
  4731 
  4732 * isatool mkdir provides easy setup of Isabelle session directories,
  4733 including proper document sources;
  4734 
  4735 * generated LaTeX sources are now deleted after successful run
  4736 (isatool document -c); may retain a copy somewhere else via -D option
  4737 of isatool usedir;
  4738 
  4739 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4740 style files, achieving self-contained LaTeX sources and simplifying
  4741 LaTeX debugging;
  4742 
  4743 * old-style theories now produce (crude) LaTeX output as well;
  4744 
  4745 * browser info session directories are now self-contained (may be put
  4746 on WWW server seperately); improved graphs of nested sessions; removed
  4747 graph for 'all sessions';
  4748 
  4749 * several improvements in isabelle style files; \isabellestyle{it}
  4750 produces fake math mode output; \isamarkupheader is now \section by
  4751 default; see lib/texinputs/isabelle.sty etc.;
  4752 
  4753 
  4754 *** Isar ***
  4755 
  4756 * Isar/Pure: local results and corresponding term bindings are now
  4757 subject to Hindley-Milner polymorphism (similar to ML); this
  4758 accommodates incremental type-inference very nicely;
  4759 
  4760 * Isar/Pure: new derived language element 'obtain' supports
  4761 generalized existence reasoning;
  4762 
  4763 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4764 support accumulation of results, without applying any rules yet;
  4765 useful to collect intermediate results without explicit name
  4766 references, and for use with transitivity rules with more than 2
  4767 premises;
  4768 
  4769 * Isar/Pure: scalable support for case-analysis type proofs: new
  4770 'case' language element refers to local contexts symbolically, as
  4771 produced by certain proof methods; internally, case names are attached
  4772 to theorems as "tags";
  4773 
  4774 * Isar/Pure: theory command 'hide' removes declarations from
  4775 class/type/const name spaces;
  4776 
  4777 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4778 indicate potential overloading;
  4779 
  4780 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4781 
  4782 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4783 "{a,b,c}" instead of {a,b,c};
  4784 
  4785 * Isar/Pure now provides its own version of intro/elim/dest
  4786 attributes; useful for building new logics, but beware of confusion
  4787 with the version in Provers/classical;
  4788 
  4789 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4790 case name 'antecedent';
  4791 
  4792 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4793 to the current context is now done automatically);
  4794 
  4795 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4796 for definining proof methods in ML;
  4797 
  4798 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4799 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4800 most cases, one should have to change intro!! to intro? only);
  4801 replaced "delrule" by "rule del";
  4802 
  4803 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4804 'symmetric' attribute (the latter supercedes [RS sym]);
  4805 
  4806 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4807 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4808 well (including splits);
  4809 
  4810 * Isar/Provers: Simplifier and Classical methods now support all kind
  4811 of modifiers used in the past, including 'cong', 'iff', etc.
  4812 
  4813 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4814 of Simplifier and Classical reasoner);
  4815 
  4816 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4817 now support named cases; major packages (inductive, datatype, primrec,
  4818 recdef) support case names and properly name parameters;
  4819 
  4820 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4821 monotonicity conditions are extracted to be proven at end of
  4822 calculations;
  4823 
  4824 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4825 method anyway;
  4826 
  4827 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4828 split_if split_if_asm; datatype package provides theorems foo.splits =
  4829 foo.split foo.split_asm for each datatype;
  4830 
  4831 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4832 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4833 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4834 use "(cases (simplified))" method in proper proof texts);
  4835 
  4836 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4837 
  4838 * Isar: names of theorems etc. may be natural numbers as well;
  4839 
  4840 * Isar: 'pr' command: optional arguments for goals_limit and
  4841 ProofContext.prems_limit; no longer prints theory contexts, but only
  4842 proof states;
  4843 
  4844 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4845 additional print modes to be specified; e.g. "pr(latex)" will print
  4846 proof state according to the Isabelle LaTeX style;
  4847 
  4848 * Isar: improved support for emulating tactic scripts, including proof
  4849 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4850 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4851 (for HOL datatypes);
  4852 
  4853 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4854 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4855 'proof method scripts' have to be in depth-first order;
  4856 
  4857 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4858 
  4859 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4860 should instead use individual commands for printing items
  4861 (print_commands, print_methods etc.);
  4862 
  4863 * Isar: added 'nothing' --- the empty list of theorems;
  4864 
  4865 
  4866 *** HOL ***
  4867 
  4868 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4869 corresponding virtual machine and a specification of its bytecode
  4870 verifier and a lightweight bytecode verifier, including proofs of
  4871 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4872 Cornelia Pusch (see also the homepage of project Bali at
  4873 http://isabelle.in.tum.de/Bali/);
  4874 
  4875 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4876 Clemens Ballarin;
  4877 
  4878 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4879 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4880 Rasmussen;
  4881 
  4882 * HOL/Lattice: fundamental concepts of lattice theory and order
  4883 structures, including duals, properties of bounds versus algebraic
  4884 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4885 Theorem for complete lattices etc.; may also serve as a demonstration
  4886 for abstract algebraic reasoning using axiomatic type classes, and
  4887 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4888 
  4889 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4890 von Oheimb;
  4891 
  4892 * HOL/IMPP: extension of IMP with local variables and mutually
  4893 recursive procedures, by David von Oheimb;
  4894 
  4895 * HOL/Lambda: converted into new-style theory and document;
  4896 
  4897 * HOL/ex/Multiquote: example of multiple nested quotations and
  4898 anti-quotations -- basically a generalized version of de-Bruijn
  4899 representation; very useful in avoiding lifting of operations;
  4900 
  4901 * HOL/record: added general record equality rule to simpset; fixed
  4902 select-update simplification procedure to handle extended records as
  4903 well; admit "r" as field name;
  4904 
  4905 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4906 other numeric types and also as the identity of groups, rings, etc.;
  4907 
  4908 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4909 Types nat and int belong to this axclass;
  4910 
  4911 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4912    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4913    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4914   two terms #m*u and #n*u are replaced by #(m+n)*u
  4915     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4916   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4917     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4918 
  4919 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4920 powerful prover for predicate logic but knows nothing of clasets; see
  4921 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4922 
  4923 * HOL: new version of "case_tac" subsumes both boolean case split and
  4924 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4925 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4926 
  4927 * HOL: simplification no longer dives into case-expressions: only the
  4928 selector expression is simplified, but not the remaining arms; to
  4929 enable full simplification of case-expressions for datatype t, you may
  4930 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4931 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4932 
  4933 * HOL/recdef: the recursion equations generated by 'recdef' for
  4934 function 'f' are now called f.simps instead of f.rules; if all
  4935 termination conditions are proved automatically, these simplification
  4936 rules are added to the simpset, as in primrec; rules may be named
  4937 individually as well, resulting in a separate list of theorems for
  4938 each equation;
  4939 
  4940 * HOL/While is a new theory that provides a while-combinator. It
  4941 permits the definition of tail-recursive functions without the
  4942 provision of a termination measure. The latter is necessary once the
  4943 invariant proof rule for while is applied.
  4944 
  4945 * HOL: new (overloaded) notation for the set of elements below/above
  4946 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  4947 
  4948 * HOL: theorems impI, allI, ballI bound as "strip";
  4949 
  4950 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  4951 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  4952 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  4953 
  4954 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4955 
  4956 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  4957 main HOL, but was unused);
  4958 
  4959 * HOL: fewer consts declared as global (e.g. have to refer to
  4960 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  4961 
  4962 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  4963 in case of overlap with user translations (e.g. judgements over
  4964 tuples); (note that the underlying logical represenation is still
  4965 bogus);
  4966 
  4967 
  4968 *** ZF ***
  4969 
  4970 * ZF: simplification automatically cancels common terms in arithmetic
  4971 expressions over nat and int;
  4972 
  4973 * ZF: new treatment of nat to minimize type-checking: all operators
  4974 coerce their operands to a natural number using the function natify,
  4975 making the algebraic laws unconditional;
  4976 
  4977 * ZF: as above, for int: operators coerce their operands to an integer
  4978 using the function intify;
  4979 
  4980 * ZF: the integer library now contains many of the usual laws for the
  4981 orderings, including $<=, and monotonicity laws for $+ and $*;
  4982 
  4983 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  4984 simplification;
  4985 
  4986 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  4987 to the simplifier and classical reasoner simultaneously;
  4988 
  4989 
  4990 *** General ***
  4991 
  4992 * Provers: blast_tac now handles actual object-logic rules as
  4993 assumptions; note that auto_tac uses blast_tac internally as well;
  4994 
  4995 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  4996 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  4997 
  4998 * Provers: delrules now handles destruct rules as well (no longer need
  4999 explicit make_elim);
  5000 
  5001 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5002   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5003 use instead the strong form,
  5004   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5005 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5006 from destruct-rules;
  5007 
  5008 * Provers: Simplifier.easy_setup provides a fast path to basic
  5009 Simplifier setup for new object-logics;
  5010 
  5011 * Pure: AST translation rules no longer require constant head on LHS;
  5012 
  5013 * Pure: improved name spaces: ambiguous output is qualified; support
  5014 for hiding of names;
  5015 
  5016 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5017 XSYMBOL_HOME; no longer need to do manual configuration in most
  5018 situations;
  5019 
  5020 * system: compression of ML heaps images may now be controlled via -c
  5021 option of isabelle and isatool usedir (currently only observed by
  5022 Poly/ML);
  5023 
  5024 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5025 useful for remote X11);
  5026 
  5027 * system: provide TAGS file for Isabelle sources;
  5028 
  5029 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5030 order;
  5031 
  5032 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5033 timing flag supersedes proof_timing and Toplevel.trace;
  5034 
  5035 * ML: new combinators |>> and |>>> for incremental transformations
  5036 with secondary results (e.g. certain theory extensions):
  5037 
  5038 * ML: PureThy.add_defs gets additional argument to indicate potential
  5039 overloading (usually false);
  5040 
  5041 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5042 results;
  5043 
  5044 
  5045 
  5046 New in Isabelle99 (October 1999)
  5047 --------------------------------
  5048 
  5049 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5050 
  5051 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5052 are no longer simplified.  (This allows the simplifier to unfold recursive
  5053 functional programs.)  To restore the old behaviour, declare
  5054 
  5055     Delcongs [if_weak_cong];
  5056 
  5057 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5058 complement;
  5059 
  5060 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5061 
  5062 * HOL/datatype: mutual_induct_tac no longer exists --
  5063   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5064 
  5065 * HOL/typedef: fixed type inference for representing set; type
  5066 arguments now have to occur explicitly on the rhs as type constraints;
  5067 
  5068 * ZF: The con_defs part of an inductive definition may no longer refer
  5069 to constants declared in the same theory;
  5070 
  5071 * HOL, ZF: the function mk_cases, generated by the inductive
  5072 definition package, has lost an argument.  To simplify its result, it
  5073 uses the default simpset instead of a supplied list of theorems.
  5074 
  5075 * HOL/List: the constructors of type list are now Nil and Cons;
  5076 
  5077 * Simplifier: the type of the infix ML functions
  5078         setSSolver addSSolver setSolver addSolver
  5079 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5080 for packaging solvers. A solver is created via
  5081         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5082 where the string argument is only a comment.
  5083 
  5084 
  5085 *** Proof tools ***
  5086 
  5087 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5088 decision procedure for linear arithmetic. Currently it is used for
  5089 types `nat', `int', and `real' in HOL (see below); it can, should and
  5090 will be instantiated for other types and logics as well.
  5091 
  5092 * The simplifier now accepts rewrite rules with flexible heads, eg
  5093      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5094   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5095   matching.
  5096 
  5097 
  5098 *** General ***
  5099 
  5100 * New Isabelle/Isar subsystem provides an alternative to traditional
  5101 tactical theorem proving; together with the ProofGeneral/isar user
  5102 interface it offers an interactive environment for developing human
  5103 readable proof documents (Isar == Intelligible semi-automated
  5104 reasoning); for further information see isatool doc isar-ref,
  5105 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5106 
  5107 * improved and simplified presentation of theories: better HTML markup
  5108 (including colors), graph views in several sizes; isatool usedir now
  5109 provides a proper interface for user theories (via -P option); actual
  5110 document preparation based on (PDF)LaTeX is available as well (for
  5111 new-style theories only); see isatool doc system for more information;
  5112 
  5113 * native support for Proof General, both for classic Isabelle and
  5114 Isabelle/Isar;
  5115 
  5116 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5117 using the graph browser tool;
  5118 
  5119 * Isabelle manuals now also available as PDF;
  5120 
  5121 * theory loader rewritten from scratch (may not be fully
  5122 bug-compatible); old loadpath variable has been replaced by show_path,
  5123 add_path, del_path, reset_path functions; new operations such as
  5124 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5125 isatool doc ref);
  5126 
  5127 * improved isatool install: option -k creates KDE application icon,
  5128 option -p DIR installs standalone binaries;
  5129 
  5130 * added ML_PLATFORM setting (useful for cross-platform installations);
  5131 more robust handling of platform specific ML images for SML/NJ;
  5132 
  5133 * the settings environment is now statically scoped, i.e. it is never
  5134 created again in sub-processes invoked from isabelle, isatool, or
  5135 Isabelle;
  5136 
  5137 * path element specification '~~' refers to '$ISABELLE_HOME';
  5138 
  5139 * in locales, the "assumes" and "defines" parts may be omitted if
  5140 empty;
  5141 
  5142 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5143 long arrows);
  5144 
  5145 * new print_mode "HTML";
  5146 
  5147 * new flag show_tags controls display of tags of theorems (which are
  5148 basically just comments that may be attached by some tools);
  5149 
  5150 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5151 mode and goal output format:
  5152 
  5153 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5154 244c244
  5155 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5156 ---
  5157 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5158 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5159 181c181
  5160 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5161 ---
  5162 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5163 
  5164 * function bind_thms stores lists of theorems (cf. bind_thm);
  5165 
  5166 * new shorthand tactics ftac, eatac, datac, fatac;
  5167 
  5168 * qed (and friends) now accept "" as result name; in that case the
  5169 theorem is not stored, but proper checks and presentation of the
  5170 result still apply;
  5171 
  5172 * theorem database now also indexes constants "Trueprop", "all",
  5173 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5174 
  5175 
  5176 *** HOL ***
  5177 
  5178 ** HOL arithmetic **
  5179 
  5180 * There are now decision procedures for linear arithmetic over nat and
  5181 int:
  5182 
  5183 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5184 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5185 are treated as atomic; subformulae not involving type `nat' or `int'
  5186 are ignored; quantified subformulae are ignored unless they are
  5187 positive universal or negative existential. The tactic has to be
  5188 invoked by hand and can be a little bit slow. In particular, the
  5189 running time is exponential in the number of occurrences of `min' and
  5190 `max', and `-' on `nat'.
  5191 
  5192 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5193 (negated) (in)equalities among the premises and the conclusion into
  5194 account (i.e. no compound formulae) and does not know about `min' and
  5195 `max', and `-' on `nat'. It is fast and is used automatically by the
  5196 simplifier.
  5197 
  5198 NB: At the moment, these decision procedures do not cope with mixed
  5199 nat/int formulae where the two parts interact, such as `m < n ==>
  5200 int(m) < int(n)'.
  5201 
  5202 * HOL/Numeral provides a generic theory of numerals (encoded
  5203 efficiently as bit strings); setup for types nat/int/real is in place;
  5204 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5205 int, existing theories and proof scripts may require a few additional
  5206 type constraints;
  5207 
  5208 * integer division and remainder can now be performed on constant
  5209 arguments;
  5210 
  5211 * many properties of integer multiplication, division and remainder
  5212 are now available;
  5213 
  5214 * An interface to the Stanford Validity Checker (SVC) is available through the
  5215 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5216 are proved automatically.  SVC must be installed separately, and its results
  5217 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5218 invocation of the underlying oracle).  For SVC see
  5219   http://verify.stanford.edu/SVC
  5220 
  5221 * IsaMakefile: the HOL-Real target now builds an actual image;
  5222 
  5223 
  5224 ** HOL misc **
  5225 
  5226 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5227 (in Isabelle/Isar) -- by Gertrud Bauer;
  5228 
  5229 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5230 analysis for assembly languages with subtypes;
  5231 
  5232 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5233 -- avoids syntactic ambiguities and treats state, transition, and
  5234 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5235 changed syntax and (many) tactics;
  5236 
  5237 * HOL/inductive: Now also handles more general introduction rules such
  5238   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5239   theorems are now maintained within the theory (maintained via the
  5240   "mono" attribute);
  5241 
  5242 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5243   (using function types) such as
  5244 
  5245   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5246 
  5247 * HOL/record: record_simproc (part of the default simpset) takes care
  5248 of selectors applied to updated records; record_split_tac is no longer
  5249 part of the default claset; update_defs may now be removed from the
  5250 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5251 
  5252   claset_ref () := claset() addSWrapper record_split_wrapper;
  5253   Delsimprocs [record_simproc]
  5254 
  5255 * HOL/typedef: fixed type inference for representing set; type
  5256 arguments now have to occur explicitly on the rhs as type constraints;
  5257 
  5258 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5259 names rather than an ML expression;
  5260 
  5261 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5262 supplied later.  Program schemes can be defined, such as
  5263     "While B C s = (if B s then While B C (C s) else s)"
  5264 where the well-founded relation can be chosen after B and C have been given.
  5265 
  5266 * HOL/List: the constructors of type list are now Nil and Cons;
  5267 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5268 course, ML tools referring to List.list.op # etc. have to be adapted;
  5269 
  5270 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5271 disabled by default; run isabelle with option -m HOL to get back to
  5272 the original Gordon/HOL-style output;
  5273 
  5274 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5275 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5276 
  5277 * HOL basic syntax simplified (more orthogonal): all variants of
  5278 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5279 Eps operator is provided as well: "SOME x. P[x]";
  5280 
  5281 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5282 
  5283 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5284 thus available for user theories;
  5285 
  5286 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5287 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5288 time;
  5289 
  5290 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5291 several times and then mp;
  5292 
  5293 
  5294 *** LK ***
  5295 
  5296 * the notation <<...>> is now available as a notation for sequences of
  5297 formulas;
  5298 
  5299 * the simplifier is now installed
  5300 
  5301 * the axiom system has been generalized (thanks to Soren Heilmann)
  5302 
  5303 * the classical reasoner now has a default rule database
  5304 
  5305 
  5306 *** ZF ***
  5307 
  5308 * new primrec section allows primitive recursive functions to be given
  5309 directly (as in HOL) over datatypes and the natural numbers;
  5310 
  5311 * new tactics induct_tac and exhaust_tac for induction (or case
  5312 analysis) over datatypes and the natural numbers;
  5313 
  5314 * the datatype declaration of type T now defines the recursor T_rec;
  5315 
  5316 * simplification automatically does freeness reasoning for datatype
  5317 constructors;
  5318 
  5319 * automatic type-inference, with AddTCs command to insert new
  5320 type-checking rules;
  5321 
  5322 * datatype introduction rules are now added as Safe Introduction rules
  5323 to the claset;
  5324 
  5325 * the syntax "if P then x else y" is now available in addition to
  5326 if(P,x,y);
  5327 
  5328 
  5329 *** Internal programming interfaces ***
  5330 
  5331 * tuned simplifier trace output; new flag debug_simp;
  5332 
  5333 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5334 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5335 
  5336 * AxClass.axclass_tac lost the theory argument;
  5337 
  5338 * tuned current_goals_markers semantics: begin / end goal avoids
  5339 printing empty lines;
  5340 
  5341 * removed prs and prs_fn hook, which was broken because it did not
  5342 include \n in its semantics, forcing writeln to add one
  5343 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5344 string -> unit if you really want to output text without newline;
  5345 
  5346 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5347 plain output, interface builders may have to enable 'isabelle_font'
  5348 mode to get Isabelle font glyphs as before;
  5349 
  5350 * refined token_translation interface; INCOMPATIBILITY: output length
  5351 now of type real instead of int;
  5352 
  5353 * theory loader actions may be traced via new ThyInfo.add_hook
  5354 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5355 your own database of information attached to *whole* theories -- as
  5356 opposed to intra-theory data slots offered via TheoryDataFun;
  5357 
  5358 * proper handling of dangling sort hypotheses (at last!);
  5359 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5360 extra sort hypotheses that can be witnessed from the type signature;
  5361 the force_strip_shyps flag is gone, any remaining shyps are simply
  5362 left in the theorem (with a warning issued by strip_shyps_warning);
  5363 
  5364 
  5365 
  5366 New in Isabelle98-1 (October 1998)
  5367 ----------------------------------
  5368 
  5369 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5370 
  5371 * several changes of automated proof tools;
  5372 
  5373 * HOL: major changes to the inductive and datatype packages, including
  5374 some minor incompatibilities of theory syntax;
  5375 
  5376 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5377 called `inj_on';
  5378 
  5379 * HOL: removed duplicate thms in Arith:
  5380   less_imp_add_less  should be replaced by  trans_less_add1
  5381   le_imp_add_le      should be replaced by  trans_le_add1
  5382 
  5383 * HOL: unary minus is now overloaded (new type constraints may be
  5384 required);
  5385 
  5386 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5387 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5388 now taken as an integer constant.
  5389 
  5390 * Pure: ML function 'theory_of' renamed to 'theory';
  5391 
  5392 
  5393 *** Proof tools ***
  5394 
  5395 * Simplifier:
  5396   1. Asm_full_simp_tac is now more aggressive.
  5397      1. It will sometimes reorient premises if that increases their power to
  5398         simplify.
  5399      2. It does no longer proceed strictly from left to right but may also
  5400         rotate premises to achieve further simplification.
  5401      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5402      old Asm_full_simp_tac in that it does not rotate premises.
  5403   2. The simplifier now knows a little bit about nat-arithmetic.
  5404 
  5405 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5406 allows for selected deletion of wrappers, by introduction of names for
  5407 wrapper functionals.  This implies that addbefore, addSbefore,
  5408 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5409 and that adding two tactics with the same name overwrites the first
  5410 one (emitting a warning).
  5411   type wrapper = (int -> tactic) -> (int -> tactic)
  5412   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5413   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5414   delWrapper, delSWrapper: claset *  string            -> claset
  5415   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5416 
  5417 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5418 semantics; addbefore now affects only the unsafe part of step_tac
  5419 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5420 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5421 by Force_tac;
  5422 
  5423 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5424 compWrapper; added safe wrapper (and access functions for it);
  5425 
  5426 * HOL/split_all_tac is now much faster and fails if there is nothing
  5427 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5428 and the names of the automatically generated variables have changed.
  5429 split_all_tac has moved within claset() from unsafe wrappers to safe
  5430 wrappers, which means that !!-bound variables are split much more
  5431 aggressively, and safe_tac and clarify_tac now split such variables.
  5432 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5433 Note: the same holds for record_split_tac, which does the job of
  5434 split_all_tac for record fields.
  5435 
  5436 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5437 permanently to the default simpset using Addsplits just like
  5438 Addsimps. They can be removed via Delsplits just like
  5439 Delsimps. Lower-case versions are also available.
  5440 
  5441 * HOL/Simplifier: The rule split_if is now part of the default
  5442 simpset. This means that the simplifier will eliminate all occurrences
  5443 of if-then-else in the conclusion of a goal. To prevent this, you can
  5444 either remove split_if completely from the default simpset by
  5445 `Delsplits [split_if]' or remove it in a specific call of the
  5446 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5447 other case splitting rules to/from the default simpset: every datatype
  5448 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5449 t is the name of the datatype).
  5450 
  5451 * Classical reasoner / Simplifier combination: new force_tac (and
  5452 derivatives Force_tac, force) combines rewriting and classical
  5453 reasoning (and whatever other tools) similarly to auto_tac, but is
  5454 aimed to solve the given subgoal completely.
  5455 
  5456 
  5457 *** General ***
  5458 
  5459 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5460 and `goalw': the theory is no longer needed as an explicit argument -
  5461 the current theory context is used; assumptions are no longer returned
  5462 at the ML-level unless one of them starts with ==> or !!; it is
  5463 recommended to convert to these new commands using isatool fixgoal
  5464 (backup your sources first!);
  5465 
  5466 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5467 the current theory context, and 'theory' to lookup stored theories;
  5468 
  5469 * new theory section 'locale' for declaring constants, assumptions and
  5470 definitions that have local scope;
  5471 
  5472 * new theory section 'nonterminals' for purely syntactic types;
  5473 
  5474 * new theory section 'setup' for generic ML setup functions
  5475 (e.g. package initialization);
  5476 
  5477 * the distribution now includes Isabelle icons: see
  5478 lib/logo/isabelle-{small,tiny}.xpm;
  5479 
  5480 * isatool install - install binaries with absolute references to
  5481 ISABELLE_HOME/bin;
  5482 
  5483 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5484 
  5485 * print mode 'emacs' reserved for Isamode;
  5486 
  5487 * support multiple print (ast) translations per constant name;
  5488 
  5489 * theorems involving oracles are now printed with a suffixed [!];
  5490 
  5491 
  5492 *** HOL ***
  5493 
  5494 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5495 
  5496 * HOL/inductive package reorganized and improved: now supports mutual
  5497 definitions such as
  5498 
  5499   inductive EVEN ODD
  5500     intrs
  5501       null "0 : EVEN"
  5502       oddI "n : EVEN ==> Suc n : ODD"
  5503       evenI "n : ODD ==> Suc n : EVEN"
  5504 
  5505 new theorem list "elims" contains an elimination rule for each of the
  5506 recursive sets; inductive definitions now handle disjunctive premises
  5507 correctly (also ZF);
  5508 
  5509 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5510 "mutual_induct" no longer exists - the induction rule is always
  5511 contained in "induct";
  5512 
  5513 
  5514 * HOL/datatype package re-implemented and greatly improved: now
  5515 supports mutually recursive datatypes such as
  5516 
  5517   datatype
  5518     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5519             | SUM ('a aexp) ('a aexp)
  5520             | DIFF ('a aexp) ('a aexp)
  5521             | NUM 'a
  5522   and
  5523     'a bexp = LESS ('a aexp) ('a aexp)
  5524             | AND ('a bexp) ('a bexp)
  5525             | OR ('a bexp) ('a bexp)
  5526 
  5527 as well as indirectly recursive datatypes such as
  5528 
  5529   datatype
  5530     ('a, 'b) term = Var 'a
  5531                   | App 'b ((('a, 'b) term) list)
  5532 
  5533 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5534 induction on mutually / indirectly recursive datatypes.
  5535 
  5536 Primrec equations are now stored in theory and can be accessed via
  5537 <function_name>.simps.
  5538 
  5539 INCOMPATIBILITIES:
  5540 
  5541   - Theories using datatypes must now have theory Datatype as an
  5542     ancestor.
  5543   - The specific <typename>.induct_tac no longer exists - use the
  5544     generic induct_tac instead.
  5545   - natE has been renamed to nat.exhaust - use exhaust_tac
  5546     instead of res_inst_tac ... natE. Note that the variable
  5547     names in nat.exhaust differ from the names in natE, this
  5548     may cause some "fragile" proofs to fail.
  5549   - The theorems split_<typename>_case and split_<typename>_case_asm
  5550     have been renamed to <typename>.split and <typename>.split_asm.
  5551   - Since default sorts of type variables are now handled correctly,
  5552     some datatype definitions may have to be annotated with explicit
  5553     sort constraints.
  5554   - Primrec definitions no longer require function name and type
  5555     of recursive argument.
  5556 
  5557 Consider using isatool fixdatatype to adapt your theories and proof
  5558 scripts to the new package (backup your sources first!).
  5559 
  5560 
  5561 * HOL/record package: considerably improved implementation; now
  5562 includes concrete syntax for record types, terms, updates; theorems
  5563 for surjective pairing and splitting !!-bound record variables; proof
  5564 support is as follows:
  5565 
  5566   1) standard conversions (selectors or updates applied to record
  5567 constructor terms) are part of the standard simpset;
  5568 
  5569   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5570 made part of standard simpset and claset via addIffs;
  5571 
  5572   3) a tactic for record field splitting (record_split_tac) is part of
  5573 the standard claset (addSWrapper);
  5574 
  5575 To get a better idea about these rules you may retrieve them via
  5576 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5577 the name of your record type.
  5578 
  5579 The split tactic 3) conceptually simplifies by the following rule:
  5580 
  5581   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5582 
  5583 Thus any record variable that is bound by meta-all will automatically
  5584 blow up into some record constructor term, consequently the
  5585 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5586 solve record problems automatically.
  5587 
  5588 
  5589 * reorganized the main HOL image: HOL/Integ and String loaded by
  5590 default; theory Main includes everything;
  5591 
  5592 * automatic simplification of integer sums and comparisons, using cancellation;
  5593 
  5594 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5595 
  5596 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5597 
  5598 * many new identities for unions, intersections, set difference, etc.;
  5599 
  5600 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5601 called split_if, split_split, split_sum_case and split_nat_case (to go
  5602 with add/delsplits);
  5603 
  5604 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5605 (?x::unit) = (); this is made part of the default simpset, which COULD
  5606 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5607 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5608 unit_abs_eta_conv is added in order to counter the effect of
  5609 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5610 %u.f();
  5611 
  5612 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5613 makes more sense);
  5614 
  5615 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5616   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5617   disjointness reasoning but breaking a few old proofs.
  5618 
  5619 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5620 to 'converse' from 'inverse' (for compatibility with ZF and some
  5621 literature);
  5622 
  5623 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5624 the well-founded relation;
  5625 
  5626 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5627     Compl A.  The "Compl" syntax remains available as input syntax for this
  5628     release ONLY.
  5629 
  5630 * HOL/Update: new theory of function updates:
  5631     f(a:=b) == %x. if x=a then b else f x
  5632 may also be iterated as in f(a:=b,c:=d,...);
  5633 
  5634 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5635 
  5636 * HOL/List:
  5637   - new function list_update written xs[i:=v] that updates the i-th
  5638     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5639   - new function `upt' written [i..j(] which generates the list
  5640     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5641     bound write [i..j], which is a shorthand for [i..j+1(].
  5642   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5643 
  5644 * HOL/Arith:
  5645   - removed 'pred' (predecessor) function;
  5646   - generalized some theorems about n-1;
  5647   - many new laws about "div" and "mod";
  5648   - new laws about greatest common divisors (see theory ex/Primes);
  5649 
  5650 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5651 instead of "inverse";
  5652 
  5653 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5654   of the multiset ordering;
  5655 
  5656 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5657   (not included by default);
  5658 
  5659 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5660 
  5661 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5662   programs, i.e. different program variables may have different types.
  5663 
  5664 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5665   [previously, this check worked only if the rewrite rule was unconditional]
  5666   Now rew can involve either definitions or equalities (either == or =).
  5667 
  5668 
  5669 *** ZF ***
  5670 
  5671 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5672   only the theorems proved on ZF.ML;
  5673 
  5674 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5675   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5676   disjointness reasoning but breaking a few old proofs.
  5677 
  5678 * ZF/Update: new theory of function updates
  5679     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5680   may also be iterated as in f(a:=b,c:=d,...);
  5681 
  5682 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5683 
  5684 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5685   [previously, this check worked only if the rewrite rule was unconditional]
  5686   Now rew can involve either definitions or equalities (either == or =).
  5687 
  5688 * case_tac provided for compatibility with HOL
  5689     (like the old excluded_middle_tac, but with subgoals swapped)
  5690 
  5691 
  5692 *** Internal programming interfaces ***
  5693 
  5694 * Pure: several new basic modules made available for general use, see
  5695 also src/Pure/README;
  5696 
  5697 * improved the theory data mechanism to support encapsulation (data
  5698 kind name replaced by private Object.kind, acting as authorization
  5699 key); new type-safe user interface via functor TheoryDataFun; generic
  5700 print_data function becomes basically useless;
  5701 
  5702 * removed global_names compatibility flag -- all theory declarations
  5703 are qualified by default;
  5704 
  5705 * module Pure/Syntax now offers quote / antiquote translation
  5706 functions (useful for Hoare logic etc. with implicit dependencies);
  5707 see HOL/ex/Antiquote for an example use;
  5708 
  5709 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5710 cterm -> thm;
  5711 
  5712 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5713 subgoal;
  5714 
  5715 * Display.print_goals function moved to Locale.print_goals;
  5716 
  5717 * standard print function for goals supports current_goals_markers
  5718 variable for marking begin of proof, end of proof, start of goal; the
  5719 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5720 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5721 for example;
  5722 
  5723 
  5724 
  5725 New in Isabelle98 (January 1998)
  5726 --------------------------------
  5727 
  5728 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5729 
  5730 * changed lexical syntax of terms / types: dots made part of long
  5731 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5732 
  5733 * simpset (and claset) reference variable replaced by functions
  5734 simpset / simpset_ref;
  5735 
  5736 * no longer supports theory aliases (via merge) and non-trivial
  5737 implicit merge of thms' signatures;
  5738 
  5739 * most internal names of constants changed due to qualified names;
  5740 
  5741 * changed Pure/Sequence interface (see Pure/seq.ML);
  5742 
  5743 
  5744 *** General Changes ***
  5745 
  5746 * hierachically structured name spaces (for consts, types, axms, thms
  5747 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5748 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5749 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5750 long_names for fully qualified output names; NOTE: ML programs
  5751 (special tactics, packages etc.) referring to internal names may have
  5752 to be adapted to cope with fully qualified names; in case of severe
  5753 backward campatibility problems try setting 'global_names' at compile
  5754 time to have enrything declared within a flat name space; one may also
  5755 fine tune name declarations in theories via the 'global' and 'local'
  5756 section;
  5757 
  5758 * reimplemented the implicit simpset and claset using the new anytype
  5759 data filed in signatures; references simpset:simpset ref etc. are
  5760 replaced by functions simpset:unit->simpset and
  5761 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5762 to patch your ML files accordingly;
  5763 
  5764 * HTML output now includes theory graph data for display with Java
  5765 applet or isatool browser; data generated automatically via isatool
  5766 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5767 
  5768 * defs may now be conditional; improved rewrite_goals_tac to handle
  5769 conditional equations;
  5770 
  5771 * defs now admits additional type arguments, using TYPE('a) syntax;
  5772 
  5773 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5774 creates a new theory node; implicit merge of thms' signatures is
  5775 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5776 transfer:theory->thm->thm in (rare) cases;
  5777 
  5778 * improved handling of draft signatures / theories; draft thms (and
  5779 ctyps, cterms) are automatically promoted to real ones;
  5780 
  5781 * slightly changed interfaces for oracles: admit many per theory, named
  5782 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5783 
  5784 * print_goals: optional output of const types (set show_consts and
  5785 show_types);
  5786 
  5787 * improved output of warnings (###) and errors (***);
  5788 
  5789 * subgoal_tac displays a warning if the new subgoal has type variables;
  5790 
  5791 * removed old README and Makefiles;
  5792 
  5793 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5794 
  5795 * removed obsolete init_pps and init_database;
  5796 
  5797 * deleted the obsolete tactical STATE, which was declared by
  5798     fun STATE tacfun st = tacfun st st;
  5799 
  5800 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5801 (which abbreviates $HOME);
  5802 
  5803 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5804 use isatool fixseq to adapt your ML programs (this works for fully
  5805 qualified references to the Sequence structure only!);
  5806 
  5807 * use_thy no longer requires writable current directory; it always
  5808 reloads .ML *and* .thy file, if either one is out of date;
  5809 
  5810 
  5811 *** Classical Reasoner ***
  5812 
  5813 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5814 tactics that use classical reasoning to simplify a subgoal without
  5815 splitting it into several subgoals;
  5816 
  5817 * Safe_tac: like safe_tac but uses the default claset;
  5818 
  5819 
  5820 *** Simplifier ***
  5821 
  5822 * added simplification meta rules:
  5823     (asm_)(full_)simplify: simpset -> thm -> thm;
  5824 
  5825 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5826 logics (again);
  5827 
  5828 * added prems argument to simplification procedures;
  5829 
  5830 * HOL, FOL, ZF: added infix function `addsplits':
  5831   instead of `<simpset> setloop (split_tac <thms>)'
  5832   you can simply write `<simpset> addsplits <thms>'
  5833 
  5834 
  5835 *** Syntax ***
  5836 
  5837 * TYPE('a) syntax for type reflection terms;
  5838 
  5839 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5840 
  5841 * pretty printer: changed order of mixfix annotation preference (again!);
  5842 
  5843 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5844 
  5845 
  5846 *** HOL ***
  5847 
  5848 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5849   with `addloop' of the simplifier to faciliate case splitting in premises.
  5850 
  5851 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5852 
  5853 * HOL/Auth: new protocol proofs including some for the Internet
  5854   protocol TLS;
  5855 
  5856 * HOL/Map: new theory of `maps' a la VDM;
  5857 
  5858 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5859 cancelling out common nat summands from =, <, <= (in)equalities, or
  5860 differences; simplification procedures nat_cancel_factor for
  5861 cancelling common factor from =, <, <= (in)equalities over natural
  5862 sums; nat_cancel contains both kinds of procedures, it is installed by
  5863 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5864 
  5865 * HOL/simplifier: terms of the form
  5866   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5867   are rewritten to
  5868   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5869   and those of the form
  5870   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5871   are rewritten to
  5872   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5873 
  5874 * HOL/datatype
  5875   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5876 
  5877   P(t_case f1 ... fn x) =
  5878      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5879         ...
  5880        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5881      )
  5882 
  5883   and a theorem `split_t_case_asm' of the form
  5884 
  5885   P(t_case f1 ... fn x) =
  5886     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5887         ...
  5888        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5889      )
  5890   which can be added to a simpset via `addsplits'. The existing theorems
  5891   expand_list_case and expand_option_case have been renamed to
  5892   split_list_case and split_option_case.
  5893 
  5894 * HOL/Arithmetic:
  5895   - `pred n' is automatically converted to `n-1'.
  5896     Users are strongly encouraged not to use `pred' any longer,
  5897     because it will disappear altogether at some point.
  5898   - Users are strongly encouraged to write "0 < n" rather than
  5899     "n ~= 0". Theorems and proof tools have been modified towards this
  5900     `standard'.
  5901 
  5902 * HOL/Lists:
  5903   the function "set_of_list" has been renamed "set" (and its theorems too);
  5904   the function "nth" now takes its arguments in the reverse order and
  5905   has acquired the infix notation "!" as in "xs!n".
  5906 
  5907 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5908 
  5909 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5910   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5911 
  5912 * HOL/record: extensible records with schematic structural subtyping
  5913 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5914 still lacks various theorems and concrete record syntax;
  5915 
  5916 
  5917 *** HOLCF ***
  5918 
  5919 * removed "axioms" and "generated by" sections;
  5920 
  5921 * replaced "ops" section by extended "consts" section, which is capable of
  5922   handling the continuous function space "->" directly;
  5923 
  5924 * domain package:
  5925   . proves theorems immediately and stores them in the theory,
  5926   . creates hierachical name space,
  5927   . now uses normal mixfix annotations (instead of cinfix...),
  5928   . minor changes to some names and values (for consistency),
  5929   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5930   . separator between mutual domain defs: changed "," to "and",
  5931   . improved handling of sort constraints;  now they have to
  5932     appear on the left-hand side of the equations only;
  5933 
  5934 * fixed LAM <x,y,zs>.b syntax;
  5935 
  5936 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5937 adm (%x. P (t x)), where P is chainfinite and t continuous;
  5938 
  5939 
  5940 *** FOL and ZF ***
  5941 
  5942 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5943   with `addloop' of the simplifier to faciliate case splitting in premises.
  5944 
  5945 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  5946 in HOL, they strip ALL and --> from proved theorems;
  5947 
  5948 
  5949 
  5950 New in Isabelle94-8 (May 1997)
  5951 ------------------------------
  5952 
  5953 *** General Changes ***
  5954 
  5955 * new utilities to build / run / maintain Isabelle etc. (in parts
  5956 still somewhat experimental); old Makefiles etc. still functional;
  5957 
  5958 * new 'Isabelle System Manual';
  5959 
  5960 * INSTALL text, together with ./configure and ./build scripts;
  5961 
  5962 * reimplemented type inference for greater efficiency, better error
  5963 messages and clean internal interface;
  5964 
  5965 * prlim command for dealing with lots of subgoals (an easier way of
  5966 setting goals_limit);
  5967 
  5968 
  5969 *** Syntax ***
  5970 
  5971 * supports alternative (named) syntax tables (parser and pretty
  5972 printer); internal interface is provided by add_modesyntax(_i);
  5973 
  5974 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  5975 be used in conjunction with the Isabelle symbol font; uses the
  5976 "symbols" syntax table;
  5977 
  5978 * added token_translation interface (may translate name tokens in
  5979 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  5980 the current print_mode); IMPORTANT: user print translation functions
  5981 are responsible for marking newly introduced bounds
  5982 (Syntax.mark_boundT);
  5983 
  5984 * token translations for modes "xterm" and "xterm_color" that display
  5985 names in bold, underline etc. or colors (which requires a color
  5986 version of xterm);
  5987 
  5988 * infixes may now be declared with names independent of their syntax;
  5989 
  5990 * added typed_print_translation (like print_translation, but may
  5991 access type of constant);
  5992 
  5993 
  5994 *** Classical Reasoner ***
  5995 
  5996 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  5997 some limitations.  Blast_tac...
  5998   + ignores addss, addbefore, addafter; this restriction is intrinsic
  5999   + ignores elimination rules that don't have the correct format
  6000         (the conclusion MUST be a formula variable)
  6001   + ignores types, which can make HOL proofs fail
  6002   + rules must not require higher-order unification, e.g. apply_type in ZF
  6003     [message "Function Var's argument not a bound variable" relates to this]
  6004   + its proof strategy is more general but can actually be slower
  6005 
  6006 * substitution with equality assumptions no longer permutes other
  6007 assumptions;
  6008 
  6009 * minor changes in semantics of addafter (now called addaltern); renamed
  6010 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6011 (and access functions for it);
  6012 
  6013 * improved combination of classical reasoner and simplifier:
  6014   + functions for handling clasimpsets
  6015   + improvement of addss: now the simplifier is called _after_ the
  6016     safe steps.
  6017   + safe variant of addss called addSss: uses safe simplifications
  6018     _during_ the safe steps. It is more complete as it allows multiple
  6019     instantiations of unknowns (e.g. with slow_tac).
  6020 
  6021 *** Simplifier ***
  6022 
  6023 * added interface for simplification procedures (functions that
  6024 produce *proven* rewrite rules on the fly, depending on current
  6025 redex);
  6026 
  6027 * ordering on terms as parameter (used for ordered rewriting);
  6028 
  6029 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6030 
  6031 * the solver is now split into a safe and an unsafe part.
  6032 This should be invisible for the normal user, except that the
  6033 functions setsolver and addsolver have been renamed to setSolver and
  6034 addSolver; added safe_asm_full_simp_tac;
  6035 
  6036 
  6037 *** HOL ***
  6038 
  6039 * a generic induction tactic `induct_tac' which works for all datatypes and
  6040 also for type `nat';
  6041 
  6042 * a generic case distinction tactic `exhaust_tac' which works for all
  6043 datatypes and also for type `nat';
  6044 
  6045 * each datatype comes with a function `size';
  6046 
  6047 * patterns in case expressions allow tuple patterns as arguments to
  6048 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6049 
  6050 * primrec now also works with type nat;
  6051 
  6052 * recdef: a new declaration form, allows general recursive functions to be
  6053 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6054 
  6055 * the constant for negation has been renamed from "not" to "Not" to
  6056 harmonize with FOL, ZF, LK, etc.;
  6057 
  6058 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6059 infinite lists;
  6060 
  6061 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6062 
  6063 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6064 problems in commutative rings, using axiomatic type classes for + and *;
  6065 
  6066 * more examples in HOL/MiniML and HOL/Auth;
  6067 
  6068 * more default rewrite rules for quantifiers, union/intersection;
  6069 
  6070 * a new constant `arbitrary == @x.False';
  6071 
  6072 * HOLCF/IOA replaces old HOL/IOA;
  6073 
  6074 * HOLCF changes: derived all rules and arities
  6075   + axiomatic type classes instead of classes
  6076   + typedef instead of faking type definitions
  6077   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6078   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6079   + eliminated the types void, one, tr
  6080   + use unit lift and bool lift (with translations) instead of one and tr
  6081   + eliminated blift from Lift3.thy (use Def instead of blift)
  6082   all eliminated rules are derived as theorems --> no visible changes ;
  6083 
  6084 
  6085 *** ZF ***
  6086 
  6087 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  6088 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  6089 as ZF_cs addSIs [equalityI];
  6090 
  6091 
  6092 
  6093 New in Isabelle94-7 (November 96)
  6094 ---------------------------------
  6095 
  6096 * allowing negative levels (as offsets) in prlev and choplev;
  6097 
  6098 * super-linear speedup for large simplifications;
  6099 
  6100 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  6101 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  6102 FAIL); can suppress it using the command Delsimps (ex_simps @
  6103 all_simps); De Morgan laws are also now included, by default;
  6104 
  6105 * improved printing of ==>  :  ~:
  6106 
  6107 * new object-logic "Sequents" adds linear logic, while replacing LK
  6108 and Modal (thanks to Sara Kalvala);
  6109 
  6110 * HOL/Auth: correctness proofs for authentication protocols;
  6111 
  6112 * HOL: new auto_tac combines rewriting and classical reasoning (many
  6113 examples on HOL/Auth);
  6114 
  6115 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  6116 the rewriter and classical reasoner simultaneously;
  6117 
  6118 * function uresult no longer returns theorems in "standard" format;
  6119 regain previous version by: val uresult = standard o uresult;
  6120 
  6121 
  6122 
  6123 New in Isabelle94-6
  6124 -------------------
  6125 
  6126 * oracles -- these establish an interface between Isabelle and trusted
  6127 external reasoners, which may deliver results as theorems;
  6128 
  6129 * proof objects (in particular record all uses of oracles);
  6130 
  6131 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  6132 
  6133 * "constdefs" section in theory files;
  6134 
  6135 * "primrec" section (HOL) no longer requires names;
  6136 
  6137 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  6138 
  6139 
  6140 
  6141 New in Isabelle94-5
  6142 -------------------
  6143 
  6144 * reduced space requirements;
  6145 
  6146 * automatic HTML generation from theories;
  6147 
  6148 * theory files no longer require "..." (quotes) around most types;
  6149 
  6150 * new examples, including two proofs of the Church-Rosser theorem;
  6151 
  6152 * non-curried (1994) version of HOL is no longer distributed;
  6153 
  6154 
  6155 
  6156 New in Isabelle94-4
  6157 -------------------
  6158 
  6159 * greatly reduced space requirements;
  6160 
  6161 * theory files (.thy) no longer require \...\ escapes at line breaks;
  6162 
  6163 * searchable theorem database (see the section "Retrieving theorems" on
  6164 page 8 of the Reference Manual);
  6165 
  6166 * new examples, including Grabczewski's monumental case study of the
  6167 Axiom of Choice;
  6168 
  6169 * The previous version of HOL renamed to Old_HOL;
  6170 
  6171 * The new version of HOL (previously called CHOL) uses a curried syntax
  6172 for functions.  Application looks like f a b instead of f(a,b);
  6173 
  6174 * Mutually recursive inductive definitions finally work in HOL;
  6175 
  6176 * In ZF, pattern-matching on tuples is now available in all abstractions and
  6177 translates to the operator "split";
  6178 
  6179 
  6180 
  6181 New in Isabelle94-3
  6182 -------------------
  6183 
  6184 * new infix operator, addss, allowing the classical reasoner to
  6185 perform simplification at each step of its search.  Example:
  6186         fast_tac (cs addss ss)
  6187 
  6188 * a new logic, CHOL, the same as HOL, but with a curried syntax
  6189 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  6190 look like (a,b) instead of <a,b>;
  6191 
  6192 * PLEASE NOTE: CHOL will eventually replace HOL!
  6193 
  6194 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  6195 It translates to the operator "split".  A new theory of integers is available;
  6196 
  6197 * In ZF, integer numerals now denote two's-complement binary integers.
  6198 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  6199 
  6200 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  6201 of the Axiom of Choice;
  6202 
  6203 
  6204 
  6205 New in Isabelle94-2
  6206 -------------------
  6207 
  6208 * Significantly faster resolution;
  6209 
  6210 * the different sections in a .thy file can now be mixed and repeated
  6211 freely;
  6212 
  6213 * Database of theorems for FOL, HOL and ZF.  New
  6214 commands including qed, qed_goal and bind_thm store theorems in the database.
  6215 
  6216 * Simple database queries: return a named theorem (get_thm) or all theorems of
  6217 a given theory (thms_of), or find out what theory a theorem was proved in
  6218 (theory_of_thm);
  6219 
  6220 * Bugs fixed in the inductive definition and datatype packages;
  6221 
  6222 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  6223 and HOL_dup_cs obsolete;
  6224 
  6225 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  6226 have been removed;
  6227 
  6228 * Simpler definition of function space in ZF;
  6229 
  6230 * new results about cardinal and ordinal arithmetic in ZF;
  6231 
  6232 * 'subtype' facility in HOL for introducing new types as subsets of existing
  6233 types;
  6234 
  6235 :mode=text:wrap=hard:maxLineLen=72: