NEWS
author haftmann
Wed Apr 22 19:16:02 2009 +0200 (2009-04-22)
changeset 30965 e0938d929bfd
parent 30964 e80c06577ade
child 30971 7fbebf75b3ef
permissions -rw-r--r--
dropped duplication
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** Pure ***
     8 
     9 * On instantiation of classes, remaining undefined class parameters are
    10 formally declared.  INCOMPATIBILITY.
    11 
    12 
    13 *** HOL ***
    14 
    15 * Class semiring_div requires superclass no_zero_divisors and proof of div_mult_mult1;
    16 theorems div_mult_mult1, div_mult_mult2, div_mult_mult1_if, div_mult_mult1 and
    17 div_mult_mult2 have been generalized to class semiring_div, subsuming former
    18 theorems zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and zdiv_zmult_zmult2.
    19 div_mult_mult1 is now [simp] by default.  INCOMPATIBILITY.
    20 
    21 * Power operations on relations and functions are now dedicated constants:
    22 
    23     relpow with infix syntax "^^"
    24     funpow with infix syntax "^o"
    25 
    26   Power operations on algebraic structures retains syntax "^" and is now defined
    27   generic in class recpower; class power disappeared.  INCOMPATIBILITY.
    28 
    29 * ML antiquotation @{code_datatype} inserts definition of a datatype generated
    30 by the code generator; see Predicate.thy for an example.
    31 
    32 
    33 New in Isabelle2009 (April 2009)
    34 --------------------------------
    35 
    36 *** General ***
    37 
    38 * Simplified main Isabelle executables, with less surprises on
    39 case-insensitive file-systems (such as Mac OS).
    40 
    41   - The main Isabelle tool wrapper is now called "isabelle" instead of
    42     "isatool."
    43 
    44   - The former "isabelle" alias for "isabelle-process" has been
    45     removed (should rarely occur to regular users).
    46 
    47   - The former "isabelle-interface" and its alias "Isabelle" have been
    48     removed (interfaces are now regular Isabelle tools).
    49 
    50 Within scripts and make files, the Isabelle environment variables
    51 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
    52 respectively.  (The latter are still available as legacy feature.)
    53 
    54 The old isabelle-interface wrapper could react in confusing ways if
    55 the interface was uninstalled or changed otherwise.  Individual
    56 interface tool configuration is now more explicit, see also the
    57 Isabelle system manual.  In particular, Proof General is now available
    58 via "isabelle emacs".
    59 
    60 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
    61 purge installed copies of Isabelle executables and re-run "isabelle
    62 install -p ...", or use symlinks.
    63 
    64 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
    65 old ~/isabelle, which was slightly non-standard and apt to cause
    66 surprises on case-insensitive file-systems (such as Mac OS).
    67 
    68 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
    69 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
    70 care is required when using older releases of Isabelle.  Note that
    71 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
    72 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
    73 
    74 * Proofs of fully specified statements are run in parallel on
    75 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
    76 a regular 4-core machine, if the initial heap space is made reasonably
    77 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
    78 
    79 * The main reference manuals ("isar-ref", "implementation", and
    80 "system") have been updated and extended.  Formally checked references
    81 as hyperlinks are now available uniformly.
    82 
    83 
    84 *** Pure ***
    85 
    86 * Complete re-implementation of locales.  INCOMPATIBILITY in several
    87 respects.  The most important changes are listed below.  See the
    88 Tutorial on Locales ("locales" manual) for details.
    89 
    90 - In locale expressions, instantiation replaces renaming.  Parameters
    91 must be declared in a for clause.  To aid compatibility with previous
    92 parameter inheritance, in locale declarations, parameters that are not
    93 'touched' (instantiation position "_" or omitted) are implicitly added
    94 with their syntax at the beginning of the for clause.
    95 
    96 - Syntax from abbreviations and definitions in locales is available in
    97 locale expressions and context elements.  The latter is particularly
    98 useful in locale declarations.
    99 
   100 - More flexible mechanisms to qualify names generated by locale
   101 expressions.  Qualifiers (prefixes) may be specified in locale
   102 expressions, and can be marked as mandatory (syntax: "name!:") or
   103 optional (syntax "name?:").  The default depends for plain "name:"
   104 depends on the situation where a locale expression is used: in
   105 commands 'locale' and 'sublocale' prefixes are optional, in
   106 'interpretation' and 'interpret' prefixes are mandatory.  The old
   107 implicit qualifiers derived from the parameter names of a locale are
   108 no longer generated.
   109 
   110 - Command "sublocale l < e" replaces "interpretation l < e".  The
   111 instantiation clause in "interpretation" and "interpret" (square
   112 brackets) is no longer available.  Use locale expressions.
   113 
   114 - When converting proof scripts, mandatory qualifiers in
   115 'interpretation' and 'interpret' should be retained by default, even
   116 if this is an INCOMPATIBILITY compared to former behavior.  In the
   117 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   118 in locale expressions range over a single locale instance only.
   119 
   120 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   121 In existing theorem specifications replace the includes element by the
   122 respective context elements of the included locale, omitting those
   123 that are already present in the theorem specification.  Multiple
   124 assume elements of a locale should be replaced by a single one
   125 involving the locale predicate.  In the proof body, declarations (most
   126 notably theorems) may be regained by interpreting the respective
   127 locales in the proof context as required (command "interpret").
   128 
   129 If using "includes" in replacement of a target solely because the
   130 parameter types in the theorem are not as general as in the target,
   131 consider declaring a new locale with additional type constraints on
   132 the parameters (context element "constrains").
   133 
   134 - Discontinued "locale (open)".  INCOMPATIBILITY.
   135 
   136 - Locale interpretation commands no longer attempt to simplify goal.
   137 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   138 methods intro_locales and unfold_locales to clarify.
   139 
   140 - Locale interpretation commands no longer accept interpretation
   141 attributes.  INCOMPATIBILITY.
   142 
   143 * Class declaration: so-called "base sort" must not be given in import
   144 list any longer, but is inferred from the specification.  Particularly
   145 in HOL, write
   146 
   147     class foo = ...
   148 
   149 instead of
   150 
   151     class foo = type + ...
   152 
   153 * Class target: global versions of theorems stemming do not carry a
   154 parameter prefix any longer.  INCOMPATIBILITY.
   155 
   156 * Class 'instance' command no longer accepts attached definitions.
   157 INCOMPATIBILITY, use proper 'instantiation' target instead.
   158 
   159 * Recovered hiding of consts, which was accidentally broken in
   160 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   161 makes c inaccessible; consider using ``hide (open) const c'' instead.
   162 
   163 * Slightly more coherent Pure syntax, with updated documentation in
   164 isar-ref manual.  Removed locales meta_term_syntax and
   165 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   166 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   167 directly in regular applications.
   168 
   169 * There is a new syntactic category "float_const" for signed decimal
   170 fractions (e.g. 123.45 or -123.45).
   171 
   172 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   173 interface with 'setup' command instead.
   174 
   175 * Command 'local_setup' is similar to 'setup', but operates on a local
   176 theory context.
   177 
   178 * The 'axiomatization' command now only works within a global theory
   179 context.  INCOMPATIBILITY.
   180 
   181 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   182 hypotheses.  Sorts required in the course of reasoning need to be
   183 covered by the constraints in the initial statement, completed by the
   184 type instance information of the background theory.  Non-trivial sort
   185 hypotheses, which rarely occur in practice, may be specified via
   186 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   187 
   188   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   189 
   190 The result contains an implicit sort hypotheses as before --
   191 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   192 normalization.
   193 
   194 * Generalized Isar history, with support for linear undo, direct state
   195 addressing etc.
   196 
   197 * Changed defaults for unify configuration options:
   198 
   199   unify_trace_bound = 50 (formerly 25)
   200   unify_search_bound = 60 (formerly 30)
   201 
   202 * Different bookkeeping for code equations (INCOMPATIBILITY):
   203 
   204   a) On theory merge, the last set of code equations for a particular
   205      constant is taken (in accordance with the policy applied by other
   206      parts of the code generator framework).
   207 
   208   b) Code equations stemming from explicit declarations (e.g. code
   209      attribute) gain priority over default code equations stemming
   210      from definition, primrec, fun etc.
   211 
   212 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   213 
   214 * Unified theorem tables for both code generators.  Thus [code
   215 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   216 
   217 * Command 'find_consts' searches for constants based on type and name
   218 patterns, e.g.
   219 
   220     find_consts "_ => bool"
   221 
   222 By default, matching is against subtypes, but it may be restricted to
   223 the whole type.  Searching by name is possible.  Multiple queries are
   224 conjunctive and queries may be negated by prefixing them with a
   225 hyphen:
   226 
   227     find_consts strict: "_ => bool" name: "Int" -"int => int"
   228 
   229 * New 'find_theorems' criterion "solves" matches theorems that
   230 directly solve the current goal (modulo higher-order unification).
   231 
   232 * Auto solve feature for main theorem statements: whenever a new goal
   233 is stated, "find_theorems solves" is called; any theorems that could
   234 solve the lemma directly are listed as part of the goal state.
   235 Cf. associated options in Proof General Isabelle settings menu,
   236 enabled by default, with reasonable timeout for pathological cases of
   237 higher-order unification.
   238 
   239 
   240 *** Document preparation ***
   241 
   242 * Antiquotation @{lemma} now imitates a regular terminal proof,
   243 demanding keyword 'by' and supporting the full method expression
   244 syntax just like the Isar command 'by'.
   245 
   246 
   247 *** HOL ***
   248 
   249 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   250 points Main and Complex_Main remain as before.
   251 
   252 * Logic image HOL-Plain provides a minimal HOL with the most important
   253 tools available (inductive, datatype, primrec, ...).  This facilitates
   254 experimentation and tool development.  Note that user applications
   255 (and library theories) should never refer to anything below theory
   256 Main, as before.
   257 
   258 * Logic image HOL-Main stops at theory Main, and thus facilitates
   259 experimentation due to shorter build times.
   260 
   261 * Logic image HOL-NSA contains theories of nonstandard analysis which
   262 were previously part of former HOL-Complex.  Entry point Hyperreal
   263 remains valid, but theories formerly using Complex_Main should now use
   264 new entry point Hypercomplex.
   265 
   266 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   267 Posix processes.  Avoids potentially expensive forking of the ML
   268 process.  New thread-based implementation also works on non-Unix
   269 platforms (Cygwin).  Provers are no longer hardwired, but defined
   270 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   271 commands are covered in the isar-ref manual.
   272 
   273 * Wrapper scripts for remote SystemOnTPTP service allows to use
   274 sledgehammer without local ATP installation (Vampire etc.). Other
   275 provers may be included via suitable ML wrappers, see also
   276 src/HOL/ATP_Linkup.thy.
   277 
   278 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   279 menu.
   280 
   281 * The metis method no longer fails because the theorem is too trivial
   282 (contains the empty clause).
   283 
   284 * The metis method now fails in the usual manner, rather than raising
   285 an exception, if it determines that it cannot prove the theorem.
   286 
   287 * Method "coherent" implements a prover for coherent logic (see also
   288 src/Tools/coherent.ML).
   289 
   290 * Constants "undefined" and "default" replace "arbitrary".  Usually
   291 "undefined" is the right choice to replace "arbitrary", though
   292 logically there is no difference.  INCOMPATIBILITY.
   293 
   294 * Command "value" now integrates different evaluation mechanisms.  The
   295 result of the first successful evaluation mechanism is printed.  In
   296 square brackets a particular named evaluation mechanisms may be
   297 specified (currently, [SML], [code] or [nbe]).  See further
   298 src/HOL/ex/Eval_Examples.thy.
   299 
   300 * Normalization by evaluation now allows non-leftlinear equations.
   301 Declare with attribute [code nbe].
   302 
   303 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   304 as the structured Isar versions "cases" and "induct", cf. the
   305 corresponding "cases" and "induct" attributes.  Mutual induction rules
   306 are now presented as a list of individual projections
   307 (e.g. foo_bar.inducts for types foo and bar); the old format with
   308 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   309 rare situations a different rule is selected --- notably nested tuple
   310 elimination instead of former prod.exhaust: use explicit (case_tac t
   311 rule: prod.exhaust) here.
   312 
   313 * Attributes "cases", "induct", "coinduct" support "del" option.
   314 
   315 * Removed fact "case_split_thm", which duplicates "case_split".
   316 
   317 * The option datatype has been moved to a new theory Option.  Renamed
   318 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   319 
   320 * New predicate "strict_mono" classifies strict functions on partial
   321 orders.  With strict functions on linear orders, reasoning about
   322 (in)equalities is facilitated by theorems "strict_mono_eq",
   323 "strict_mono_less_eq" and "strict_mono_less".
   324 
   325 * Some set operations are now proper qualified constants with
   326 authentic syntax.  INCOMPATIBILITY:
   327 
   328     op Int ~>   Set.Int
   329     op Un ~>    Set.Un
   330     INTER ~>    Set.INTER
   331     UNION ~>    Set.UNION
   332     Inter ~>    Set.Inter
   333     Union ~>    Set.Union
   334     {} ~>       Set.empty
   335     UNIV ~>     Set.UNIV
   336 
   337 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   338 theory Set.
   339 
   340 * Auxiliary class "itself" has disappeared -- classes without any
   341 parameter are treated as expected by the 'class' command.
   342 
   343 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   344 
   345 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   346 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   347 
   348 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   349 method "approximation".  It proves formulas on real values by using
   350 interval arithmetic.  In the formulas are also the transcendental
   351 functions sin, cos, tan, atan, ln, exp and the constant pi are
   352 allowed. For examples see
   353 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   354 
   355 * Theory "Reflection" now resides in HOL/Library.
   356 
   357 * Entry point to Word library now simply named "Word".
   358 INCOMPATIBILITY.
   359 
   360 * Made source layout more coherent with logical distribution
   361 structure:
   362 
   363     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   364     src/HOL/Library/Code_Message.thy ~> src/HOL/
   365     src/HOL/Library/GCD.thy ~> src/HOL/
   366     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   367     src/HOL/Library/Parity.thy ~> src/HOL/
   368     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   369     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   370     src/HOL/Real/Lubs.thy ~> src/HOL/
   371     src/HOL/Real/PReal.thy ~> src/HOL/
   372     src/HOL/Real/Rational.thy ~> src/HOL/
   373     src/HOL/Real/RComplete.thy ~> src/HOL/
   374     src/HOL/Real/RealDef.thy ~> src/HOL/
   375     src/HOL/Real/RealPow.thy ~> src/HOL/
   376     src/HOL/Real/Real.thy ~> src/HOL/
   377     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   378     src/HOL/Complex/Complex.thy ~> src/HOL/
   379     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   380     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   381     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   382     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   383     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   384     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   385     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   386     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   387     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   388     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   389     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   390     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   391     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   392     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   393     src/HOL/Real/Float ~> src/HOL/Library/
   394     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   395     src/HOL/Real/RealVector.thy ~> src/HOL/
   396 
   397     src/HOL/arith_data.ML ~> src/HOL/Tools
   398     src/HOL/hologic.ML ~> src/HOL/Tools
   399     src/HOL/simpdata.ML ~> src/HOL/Tools
   400     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   401     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   402     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   403     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   404     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   405     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   406     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   407 
   408     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   409     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   410     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   411     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   412     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   413     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   414 
   415 * If methods "eval" and "evaluation" encounter a structured proof
   416 state with !!/==>, only the conclusion is evaluated to True (if
   417 possible), avoiding strange error messages.
   418 
   419 * Method "sizechange" automates termination proofs using (a
   420 modification of) the size-change principle.  Requires SAT solver.  See
   421 src/HOL/ex/Termination.thy for examples.
   422 
   423 * Simplifier: simproc for let expressions now unfolds if bound
   424 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   425 
   426 * Method "arith": Linear arithmetic now ignores all inequalities when
   427 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   428 
   429 * New attribute "arith" for facts that should always be used
   430 automatically by arithmetic. It is intended to be used locally in
   431 proofs, e.g.
   432 
   433   assumes [arith]: "x > 0"
   434 
   435 Global usage is discouraged because of possible performance impact.
   436 
   437 * New classes "top" and "bot" with corresponding operations "top" and
   438 "bot" in theory Orderings; instantiation of class "complete_lattice"
   439 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   440 
   441 * Changed definition lemma "less_fun_def" in order to provide an
   442 instance for preorders on functions; use lemma "less_le" instead.
   443 INCOMPATIBILITY.
   444 
   445 * Theory Orderings: class "wellorder" moved here, with explicit
   446 induction rule "less_induct" as assumption.  For instantiation of
   447 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   448 INCOMPATIBILITY.
   449 
   450 * Theory Orderings: added class "preorder" as superclass of "order".
   451 INCOMPATIBILITY: Instantiation proofs for order, linorder
   452 etc. slightly changed.  Some theorems named order_class.* now named
   453 preorder_class.*.
   454 
   455 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   456 "diag" to "Id_on".
   457 
   458 * Theory Finite_Set: added a new fold combinator of type
   459 
   460   ('a => 'b => 'b) => 'b => 'a set => 'b
   461 
   462 Occasionally this is more convenient than the old fold combinator
   463 which is now defined in terms of the new one and renamed to
   464 fold_image.
   465 
   466 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   467 and "ring_simps" have been replaced by "algebra_simps" (which can be
   468 extended with further lemmas!).  At the moment both still exist but
   469 the former will disappear at some point.
   470 
   471 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   472 class recpower.  Type-specific simp rules for various recpower types
   473 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   474 
   475 rat_power_0    -> power_0
   476 rat_power_Suc  -> power_Suc
   477 realpow_0      -> power_0
   478 realpow_Suc    -> power_Suc
   479 complexpow_0   -> power_0
   480 complexpow_Suc -> power_Suc
   481 power_poly_0   -> power_0
   482 power_poly_Suc -> power_Suc
   483 
   484 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   485 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   486 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   487 of lemmas from Divides has been generalized from nat to class
   488 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   489 renames resulting from duplicate elimination:
   490 
   491     dvd_def_mod ~>          dvd_eq_mod_eq_0
   492     zero_dvd_iff ~>         dvd_0_left_iff
   493     dvd_0 ~>                dvd_0_right
   494     DIVISION_BY_ZERO_DIV ~> div_by_0
   495     DIVISION_BY_ZERO_MOD ~> mod_by_0
   496     mult_div ~>             div_mult_self2_is_id
   497     mult_mod ~>             mod_mult_self2_is_0
   498 
   499 * Theory IntDiv: removed many lemmas that are instances of class-based
   500 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   501 rename old lemmas as follows:
   502 
   503 dvd_diff               -> nat_dvd_diff
   504 dvd_zminus_iff         -> dvd_minus_iff
   505 mod_add1_eq            -> mod_add_eq
   506 mod_mult1_eq           -> mod_mult_right_eq
   507 mod_mult1_eq'          -> mod_mult_left_eq
   508 mod_mult_distrib_mod   -> mod_mult_eq
   509 nat_mod_add_left_eq    -> mod_add_left_eq
   510 nat_mod_add_right_eq   -> mod_add_right_eq
   511 nat_mod_div_trivial    -> mod_div_trivial
   512 nat_mod_mod_trivial    -> mod_mod_trivial
   513 zdiv_zadd_self1        -> div_add_self1
   514 zdiv_zadd_self2        -> div_add_self2
   515 zdiv_zmult_self1       -> div_mult_self2_is_id
   516 zdiv_zmult_self2       -> div_mult_self1_is_id
   517 zdvd_triv_left         -> dvd_triv_left
   518 zdvd_triv_right        -> dvd_triv_right
   519 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   520 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   521 zmod_zadd_left_eq      -> mod_add_left_eq
   522 zmod_zadd_right_eq     -> mod_add_right_eq
   523 zmod_zadd_self1        -> mod_add_self1
   524 zmod_zadd_self2        -> mod_add_self2
   525 zmod_zadd1_eq          -> mod_add_eq
   526 zmod_zdiff1_eq         -> mod_diff_eq
   527 zmod_zdvd_zmod         -> mod_mod_cancel
   528 zmod_zmod_cancel       -> mod_mod_cancel
   529 zmod_zmult_self1       -> mod_mult_self2_is_0
   530 zmod_zmult_self2       -> mod_mult_self1_is_0
   531 zmod_1                 -> mod_by_1
   532 zdiv_1                 -> div_by_1
   533 zdvd_abs1              -> abs_dvd_iff
   534 zdvd_abs2              -> dvd_abs_iff
   535 zdvd_refl              -> dvd_refl
   536 zdvd_trans             -> dvd_trans
   537 zdvd_zadd              -> dvd_add
   538 zdvd_zdiff             -> dvd_diff
   539 zdvd_zminus_iff        -> dvd_minus_iff
   540 zdvd_zminus2_iff       -> minus_dvd_iff
   541 zdvd_zmultD            -> dvd_mult_right
   542 zdvd_zmultD2           -> dvd_mult_left
   543 zdvd_zmult_mono        -> mult_dvd_mono
   544 zdvd_0_right           -> dvd_0_right
   545 zdvd_0_left            -> dvd_0_left_iff
   546 zdvd_1_left            -> one_dvd
   547 zminus_dvd_iff         -> minus_dvd_iff
   548 
   549 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   550 
   551 * The real numbers offer decimal input syntax: 12.34 is translated
   552 into 1234/10^2. This translation is not reversed upon output.
   553 
   554 * Theory Library/Polynomial defines an abstract type 'a poly of
   555 univariate polynomials with coefficients of type 'a.  In addition to
   556 the standard ring operations, it also supports div and mod.  Code
   557 generation is also supported, using list-style constructors.
   558 
   559 * Theory Library/Inner_Product defines a class of real_inner for real
   560 inner product spaces, with an overloaded operation inner :: 'a => 'a
   561 => real.  Class real_inner is a subclass of real_normed_vector from
   562 theory RealVector.
   563 
   564 * Theory Library/Product_Vector provides instances for the product
   565 type 'a * 'b of several classes from RealVector and Inner_Product.
   566 Definitions of addition, subtraction, scalar multiplication, norms,
   567 and inner products are included.
   568 
   569 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   570 addition to the field operations, numerals and case syntax are also
   571 supported.
   572 
   573 * Theory Library/Diagonalize provides constructive version of Cantor's
   574 first diagonalization argument.
   575 
   576 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   577 zlcm (for int); carried together from various gcd/lcm developements in
   578 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   579 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   580 may recover tupled syntax as follows:
   581 
   582     hide (open) const gcd
   583     abbreviation gcd where
   584       "gcd == (%(a, b). GCD.gcd a b)"
   585     notation (output)
   586       GCD.gcd ("gcd '(_, _')")
   587 
   588 The same works for lcm, zgcd, zlcm.
   589 
   590 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   591 instantiations for algebraic structures.  Removed some duplicate
   592 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   593 
   594 * ML antiquotation @{code} takes a constant as argument and generates
   595 corresponding code in background and inserts name of the corresponding
   596 resulting ML value/function/datatype constructor binding in place.
   597 All occurrences of @{code} with a single ML block are generated
   598 simultaneously.  Provides a generic and safe interface for
   599 instrumentalizing code generation.  See
   600 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   601 In future you ought to refrain from ad-hoc compiling generated SML
   602 code on the ML toplevel.  Note that (for technical reasons) @{code}
   603 cannot refer to constants for which user-defined serializations are
   604 set.  Refer to the corresponding ML counterpart directly in that
   605 cases.
   606 
   607 * Command 'rep_datatype': instead of theorem names the command now
   608 takes a list of terms denoting the constructors of the type to be
   609 represented as datatype.  The characteristic theorems have to be
   610 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   611 have disappeared in favour of existing ones:
   612 
   613     unit_induct                 ~> unit.induct
   614     prod_induct                 ~> prod.induct
   615     sum_induct                  ~> sum.induct
   616     Suc_Suc_eq                  ~> nat.inject
   617     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   618 
   619 
   620 *** HOL-Algebra ***
   621 
   622 * New locales for orders and lattices where the equivalence relation
   623 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   624 locales use a record structure with field eq for the equivalence.
   625 
   626 * New theory of factorial domains.
   627 
   628 * Units_l_inv and Units_r_inv are now simp rules by default.
   629 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   630 and/or r_inv will now also require deletion of these lemmas.
   631 
   632 * Renamed the following theorems, INCOMPATIBILITY:
   633 
   634 UpperD ~> Upper_memD
   635 LowerD ~> Lower_memD
   636 least_carrier ~> least_closed
   637 greatest_carrier ~> greatest_closed
   638 greatest_Lower_above ~> greatest_Lower_below
   639 one_zero ~> carrier_one_zero
   640 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   641 
   642 
   643 *** HOL-Nominal ***
   644 
   645 * Nominal datatypes can now contain type-variables.
   646 
   647 * Commands 'nominal_inductive' and 'equivariance' work with local
   648 theory targets.
   649 
   650 * Nominal primrec can now works with local theory targets and its
   651 specification syntax now conforms to the general format as seen in
   652 'inductive' etc.
   653 
   654 * Method "perm_simp" honours the standard simplifier attributes
   655 (no_asm), (no_asm_use) etc.
   656 
   657 * The new predicate #* is defined like freshness, except that on the
   658 left hand side can be a set or list of atoms.
   659 
   660 * Experimental command 'nominal_inductive2' derives strong induction
   661 principles for inductive definitions.  In contrast to
   662 'nominal_inductive', which can only deal with a fixed number of
   663 binders, it can deal with arbitrary expressions standing for sets of
   664 atoms to be avoided.  The only inductive definition we have at the
   665 moment that needs this generalisation is the typing rule for Lets in
   666 the algorithm W:
   667 
   668  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   669  -----------------------------------------------------------------
   670          Gamma |- Let x be t1 in t2 : T2
   671 
   672 In this rule one wants to avoid all the binders that are introduced by
   673 "close Gamma T1".  We are looking for other examples where this
   674 feature might be useful.  Please let us know.
   675 
   676 
   677 *** HOLCF ***
   678 
   679 * Reimplemented the simplification procedure for proving continuity
   680 subgoals.  The new simproc is extensible; users can declare additional
   681 continuity introduction rules with the attribute [cont2cont].
   682 
   683 * The continuity simproc now uses a different introduction rule for
   684 solving continuity subgoals on terms with lambda abstractions.  In
   685 some rare cases the new simproc may fail to solve subgoals that the
   686 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   687 Potential INCOMPATIBILITY.
   688 
   689 * Command 'fixrec': specification syntax now conforms to the general
   690 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   691 examples.  INCOMPATIBILITY.
   692 
   693 
   694 *** ZF ***
   695 
   696 * Proof of Zorn's Lemma for partial orders.
   697 
   698 
   699 *** ML ***
   700 
   701 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   702 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   703 depends on multithreading, so timouts will not work before Poly/ML
   704 5.2.1!
   705 
   706 * High-level support for concurrent ML programming, see
   707 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   708 particularly convenient to organize independent functional
   709 computations.  The concept of "synchronized variables" provides a
   710 higher-order interface for components with shared state, avoiding the
   711 delicate details of mutexes and condition variables.  (Requires
   712 Poly/ML 5.2.1 or later.)
   713 
   714 * ML bindings produced via Isar commands are stored within the Isar
   715 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   716 become thread-safe and work with undo as expected (concerning
   717 top-level bindings, not side-effects on global references).
   718 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   719 compiler at runtime; really global bindings need to be given outside a
   720 theory.  (Requires Poly/ML 5.2 or later.)
   721 
   722 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   723 context.  Top-level ML bindings are stored within the proof context in
   724 a purely sequential fashion, disregarding the nested proof structure.
   725 ML bindings introduced by 'ML_prf' are discarded at the end of the
   726 proof.  (Requires Poly/ML 5.2 or later.)
   727 
   728 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   729 and Method.setup, as well as Isar commands 'attribute_setup' and
   730 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   731 existing code accordingly, or use plain 'setup' together with old
   732 Method.add_method.
   733 
   734 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   735 to 'a -> thm, while results are always tagged with an authentic oracle
   736 name.  The Isar command 'oracle' is now polymorphic, no argument type
   737 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   738 accordingly.  Note that extra performance may be gained by producing
   739 the cterm carefully, avoiding slow Thm.cterm_of.
   740 
   741 * Simplified interface for defining document antiquotations via
   742 ThyOutput.antiquotation, ThyOutput.output, and optionally
   743 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   744 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   745 examples.
   746 
   747 * More systematic treatment of long names, abstract name bindings, and
   748 name space operations.  Basic operations on qualified names have been
   749 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   750 Long_Name.append.  Old type bstring has been mostly replaced by
   751 abstract type binding (see structure Binding), which supports precise
   752 qualification by packages and local theory targets, as well as proper
   753 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   754 bstring values into Binding.name, or better pass through abstract
   755 bindings everywhere.  See further src/Pure/General/long_name.ML,
   756 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   757 
   758 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   759 LocalTheory.note etc.) now refer to the *full* internal name, not the
   760 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   761 
   762 * Disposed old type and term read functions (Sign.read_def_typ,
   763 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   764 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   765 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   766 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   767 resort for legacy applications.
   768 
   769 * Disposed old declarations, tactics, tactic combinators that refer to
   770 the simpset or claset of an implicit theory (such as Addsimps,
   771 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   772 embedded ML text, or local_simpset_of with a proper context passed as
   773 explicit runtime argument.
   774 
   775 * Rules and tactics that read instantiations (read_instantiate,
   776 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   777 context, which is required for parsing and type-checking.  Moreover,
   778 the variables are specified as plain indexnames, not string encodings
   779 thereof.  INCOMPATIBILITY.
   780 
   781 * Generic Toplevel.add_hook interface allows to analyze the result of
   782 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   783 for theorem dependency output of transactions resulting in a new
   784 theory state.
   785 
   786 * ML antiquotations: block-structured compilation context indicated by
   787 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   788 
   789   @{binding name}                         - basic name binding
   790   @{let ?pat = term}                      - term abbreviation (HO matching)
   791   @{note name = fact}                     - fact abbreviation
   792   @{thm fact}                             - singleton fact (with attributes)
   793   @{thms fact}                            - general fact (with attributes)
   794   @{lemma prop by method}                 - singleton goal
   795   @{lemma prop by meth1 meth2}            - singleton goal
   796   @{lemma prop1 ... propN by method}      - general goal
   797   @{lemma prop1 ... propN by meth1 meth2} - general goal
   798   @{lemma (open) ...}                     - open derivation
   799 
   800 
   801 *** System ***
   802 
   803 * The Isabelle "emacs" tool provides a specific interface to invoke
   804 Proof General / Emacs, with more explicit failure if that is not
   805 installed (the old isabelle-interface script silently falls back on
   806 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   807 installation location of the Proof General distribution.
   808 
   809 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   810 the Isabelle process into a JVM/Scala application.  See
   811 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   812 process wrapper has been discontinued.)
   813 
   814 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   815 
   816 * Various status messages (with exact source position information) are
   817 emitted, if proper markup print mode is enabled.  This allows
   818 user-interface components to provide detailed feedback on internal
   819 prover operations.
   820 
   821 
   822 
   823 New in Isabelle2008 (June 2008)
   824 -------------------------------
   825 
   826 *** General ***
   827 
   828 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   829 and updated, with formally checked references as hyperlinks.
   830 
   831 * Theory loader: use_thy (and similar operations) no longer set the
   832 implicit ML context, which was occasionally hard to predict and in
   833 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   834 provides a proper context already.
   835 
   836 * Theory loader: old-style ML proof scripts being *attached* to a thy
   837 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   838 'use' within a theory file will do the job.
   839 
   840 * Name space merge now observes canonical order, i.e. the second space
   841 is inserted into the first one, while existing entries in the first
   842 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   843 swap theory imports.
   844 
   845 * Syntax: symbol \<chi> is now considered a letter.  Potential
   846 INCOMPATIBILITY in identifier syntax etc.
   847 
   848 * Outer syntax: string tokens no longer admit escaped white space,
   849 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   850 white space without escapes.
   851 
   852 * Outer syntax: string tokens may contain arbitrary character codes
   853 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   854 "foo_bar".
   855 
   856 
   857 *** Pure ***
   858 
   859 * Context-dependent token translations.  Default setup reverts locally
   860 fixed variables, and adds hilite markup for undeclared frees.
   861 
   862 * Unused theorems can be found using the new command 'unused_thms'.
   863 There are three ways of invoking it:
   864 
   865 (1) unused_thms
   866      Only finds unused theorems in the current theory.
   867 
   868 (2) unused_thms thy_1 ... thy_n -
   869      Finds unused theorems in the current theory and all of its ancestors,
   870      excluding the theories thy_1 ... thy_n and all of their ancestors.
   871 
   872 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   873      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   874      their ancestors, excluding the theories thy_1 ... thy_n and all of
   875      their ancestors.
   876 
   877 In order to increase the readability of the list produced by
   878 unused_thms, theorems that have been created by a particular instance
   879 of a theory command such as 'inductive' or 'function' are considered
   880 to belong to the same "group", meaning that if at least one theorem in
   881 this group is used, the other theorems in the same group are no longer
   882 reported as unused.  Moreover, if all theorems in the group are
   883 unused, only one theorem in the group is displayed.
   884 
   885 Note that proof objects have to be switched on in order for
   886 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   887 usually the case when using Proof General with the default settings).
   888 
   889 * Authentic naming of facts disallows ad-hoc overwriting of previous
   890 theorems within the same name space.  INCOMPATIBILITY, need to remove
   891 duplicate fact bindings, or even accidental fact duplications.  Note
   892 that tools may maintain dynamically scoped facts systematically, using
   893 PureThy.add_thms_dynamic.
   894 
   895 * Command 'hide' now allows to hide from "fact" name space as well.
   896 
   897 * Eliminated destructive theorem database, simpset, claset, and
   898 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   899 update of theories within ML code.
   900 
   901 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   902 INCOMPATIBILITY, object-logics depending on former Pure require
   903 additional setup PureThy.old_appl_syntax_setup; object-logics
   904 depending on former CPure need to refer to Pure.
   905 
   906 * Commands 'use' and 'ML' are now purely functional, operating on
   907 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
   908 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
   909 INCOMPATIBILITY.
   910 
   911 * Command 'setup': discontinued implicit version with ML reference.
   912 
   913 * Instantiation target allows for simultaneous specification of class
   914 instance operations together with an instantiation proof.
   915 Type-checking phase allows to refer to class operations uniformly.
   916 See src/HOL/Complex/Complex.thy for an Isar example and
   917 src/HOL/Library/Eval.thy for an ML example.
   918 
   919 * Indexing of literal facts: be more serious about including only
   920 facts from the visible specification/proof context, but not the
   921 background context (locale etc.).  Affects `prop` notation and method
   922 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
   923 situations.
   924 
   925 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
   926 "(open)" option, which used to expose internal bound variables to the
   927 proof text.
   928 
   929 * Isar statements: removed obsolete case "rule_context".
   930 INCOMPATIBILITY, better use explicit fixes/assumes.
   931 
   932 * Locale proofs: default proof step now includes 'unfold_locales';
   933 hence 'proof' without argument may be used to unfold locale
   934 predicates.
   935 
   936 
   937 *** Document preparation ***
   938 
   939 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
   940 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
   941 obsolete thumbpdf setup (contemporary PDF viewers do this on the
   942 spot); renamed link color from "darkblue" to "linkcolor" (default
   943 value unchanged, can be redefined via \definecolor); no longer sets
   944 "a4paper" option (unnecessary or even intrusive).
   945 
   946 * Antiquotation @{lemma A method} proves proposition A by the given
   947 method (either a method name or a method name plus (optional) method
   948 arguments in parentheses) and prints A just like @{prop A}.
   949 
   950 
   951 *** HOL ***
   952 
   953 * New primrec package.  Specification syntax conforms in style to
   954 definition/function/....  No separate induction rule is provided.  The
   955 "primrec" command distinguishes old-style and new-style specifications
   956 by syntax.  The former primrec package is now named OldPrimrecPackage.
   957 When adjusting theories, beware: constants stemming from new-style
   958 primrec specifications have authentic syntax.
   959 
   960 * Metis prover is now an order of magnitude faster, and also works
   961 with multithreading.
   962 
   963 * Metis: the maximum number of clauses that can be produced from a
   964 theorem is now given by the attribute max_clauses.  Theorems that
   965 exceed this number are ignored, with a warning printed.
   966 
   967 * Sledgehammer no longer produces structured proofs by default. To
   968 enable, declare [[sledgehammer_full = true]].  Attributes
   969 reconstruction_modulus, reconstruction_sorts renamed
   970 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
   971 
   972 * Method "induct_scheme" derives user-specified induction rules
   973 from well-founded induction and completeness of patterns. This factors
   974 out some operations that are done internally by the function package
   975 and makes them available separately.  See
   976 src/HOL/ex/Induction_Scheme.thy for examples.
   977 
   978 * More flexible generation of measure functions for termination
   979 proofs: Measure functions can be declared by proving a rule of the
   980 form "is_measure f" and giving it the [measure_function] attribute.
   981 The "is_measure" predicate is logically meaningless (always true), and
   982 just guides the heuristic.  To find suitable measure functions, the
   983 termination prover sets up the goal "is_measure ?f" of the appropriate
   984 type and generates all solutions by prolog-style backwards proof using
   985 the declared rules.
   986 
   987 This setup also deals with rules like 
   988 
   989   "is_measure f ==> is_measure (list_size f)"
   990 
   991 which accommodates nested datatypes that recurse through lists.
   992 Similar rules are predeclared for products and option types.
   993 
   994 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
   995 
   996   INCOMPATIBILITIES:
   997 
   998   - Definitions of overloaded constants on sets have to be replaced by
   999     definitions on => and bool.
  1000 
  1001   - Some definitions of overloaded operators on sets can now be proved
  1002     using the definitions of the operators on => and bool.  Therefore,
  1003     the following theorems have been renamed:
  1004 
  1005       subset_def   -> subset_eq
  1006       psubset_def  -> psubset_eq
  1007       set_diff_def -> set_diff_eq
  1008       Compl_def    -> Compl_eq
  1009       Sup_set_def  -> Sup_set_eq
  1010       Inf_set_def  -> Inf_set_eq
  1011       sup_set_def  -> sup_set_eq
  1012       inf_set_def  -> inf_set_eq
  1013 
  1014   - Due to the incompleteness of the HO unification algorithm, some
  1015     rules such as subst may require manual instantiation, if some of
  1016     the unknowns in the rule is a set.
  1017 
  1018   - Higher order unification and forward proofs:
  1019     The proof pattern
  1020 
  1021       have "P (S::'a set)" <...>
  1022       then have "EX S. P S" ..
  1023 
  1024     no longer works (due to the incompleteness of the HO unification
  1025     algorithm) and must be replaced by the pattern
  1026 
  1027       have "EX S. P S"
  1028       proof
  1029         show "P S" <...>
  1030       qed
  1031 
  1032   - Calculational reasoning with subst (or similar rules):
  1033     The proof pattern
  1034 
  1035       have "P (S::'a set)" <...>
  1036       also have "S = T" <...>
  1037       finally have "P T" .
  1038 
  1039     no longer works (for similar reasons as the previous example) and
  1040     must be replaced by something like
  1041 
  1042       have "P (S::'a set)" <...>
  1043       moreover have "S = T" <...>
  1044       ultimately have "P T" by simp
  1045 
  1046   - Tactics or packages written in ML code:
  1047     Code performing pattern matching on types via
  1048 
  1049       Type ("set", [T]) => ...
  1050 
  1051     must be rewritten. Moreover, functions like strip_type or
  1052     binder_types no longer return the right value when applied to a
  1053     type of the form
  1054 
  1055       T1 => ... => Tn => U => bool
  1056 
  1057     rather than
  1058 
  1059       T1 => ... => Tn => U set
  1060 
  1061 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1062 Wellfounded_Relations to theory Wellfounded.
  1063 
  1064 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1065 
  1066 * Class finite no longer treats UNIV as class parameter.  Use class
  1067 enum from theory Library/Enum instead to achieve a similar effect.
  1068 INCOMPATIBILITY.
  1069 
  1070 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1071 and "Cons".  INCOMPATIBILITY.
  1072 
  1073 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1074 Potential INCOMPATIBILITY.
  1075 
  1076 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1077 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1078 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1079 
  1080 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1081 the same name in theory Orderings:
  1082 
  1083   less_trans
  1084   less_linear
  1085   le_imp_less_or_eq
  1086   le_less_trans
  1087   less_le_trans
  1088   less_not_sym
  1089   less_asym
  1090 
  1091 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1092 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1093 and different variable names.
  1094 
  1095 * Library/Option_ord.thy: Canonical order on option type.
  1096 
  1097 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1098 finite maps.
  1099 
  1100 * Library/Countable.thy: Type class for countable types.
  1101 
  1102 * Theory Int: The representation of numerals has changed.  The infix
  1103 operator BIT and the bit datatype with constructors B0 and B1 have
  1104 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1105 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1106 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1107 accordingly.
  1108 
  1109 * Theory Nat: definition of <= and < on natural numbers no longer
  1110 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1111 le_def and less_def have disappeared.  Consider lemmas not_less
  1112 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1113 
  1114 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1115 (whose purpose mainly is for various fold_set functionals) have been
  1116 abandoned in favor of the existing algebraic classes
  1117 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1118 lower_semilattice (resp. upper_semilattice) and linorder.
  1119 INCOMPATIBILITY.
  1120 
  1121 * Theory Transitive_Closure: induct and cases rules now declare proper
  1122 case_names ("base" and "step").  INCOMPATIBILITY.
  1123 
  1124 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1125 lattices.  The form set-specific version is available as
  1126 Inductive.lfp_ordinal_induct_set.
  1127 
  1128 * Renamed theorems "power.simps" to "power_int.simps".
  1129 INCOMPATIBILITY.
  1130 
  1131 * Class semiring_div provides basic abstract properties of semirings
  1132 with division and modulo operations.  Subsumes former class dvd_mod.
  1133 
  1134 * Merged theories IntDef, Numeral and IntArith into unified theory
  1135 Int.  INCOMPATIBILITY.
  1136 
  1137 * Theory Library/Code_Index: type "index" now represents natural
  1138 numbers rather than integers.  INCOMPATIBILITY.
  1139 
  1140 * New class "uminus" with operation "uminus" (split of from class
  1141 "minus" which now only has operation "minus", binary).
  1142 INCOMPATIBILITY.
  1143 
  1144 * Constants "card", "internal_split", "option_map" now with authentic
  1145 syntax.  INCOMPATIBILITY.
  1146 
  1147 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1148 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1149 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1150 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1151 Sup_set_def, le_def, less_def, option_map_def now with object
  1152 equality.  INCOMPATIBILITY.
  1153 
  1154 * Records. Removed K_record, and replaced it by pure lambda term
  1155 %x. c. The simplifier setup is now more robust against eta expansion.
  1156 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1157 
  1158 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1159 
  1160 * Library/ListVector: new theory of arithmetic vector operations.
  1161 
  1162 * Library/Order_Relation: new theory of various orderings as sets of
  1163 pairs.  Defines preorders, partial orders, linear orders and
  1164 well-orders on sets and on types.
  1165 
  1166 
  1167 *** ZF ***
  1168 
  1169 * Renamed some theories to allow to loading both ZF and HOL in the
  1170 same session:
  1171 
  1172   Datatype  -> Datatype_ZF
  1173   Inductive -> Inductive_ZF
  1174   Int       -> Int_ZF
  1175   IntDiv    -> IntDiv_ZF
  1176   Nat       -> Nat_ZF
  1177   List      -> List_ZF
  1178   Main      -> Main_ZF
  1179 
  1180 INCOMPATIBILITY: ZF theories that import individual theories below
  1181 Main might need to be adapted.  Regular theory Main is still
  1182 available, as trivial extension of Main_ZF.
  1183 
  1184 
  1185 *** ML ***
  1186 
  1187 * ML within Isar: antiquotation @{const name} or @{const
  1188 name(typargs)} produces statically-checked Const term.
  1189 
  1190 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1191 (of the same name).  Removed obsolete print command.
  1192 
  1193 * Removed obsolete "use_legacy_bindings" function.
  1194 
  1195 * The ``print mode'' is now a thread-local value derived from a global
  1196 template (the former print_mode reference), thus access becomes
  1197 non-critical.  The global print_mode reference is for session
  1198 management only; user-code should use print_mode_value,
  1199 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1200 
  1201 * Functions system/system_out provide a robust way to invoke external
  1202 shell commands, with propagation of interrupts (requires Poly/ML
  1203 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1204 
  1205 
  1206 *** System ***
  1207 
  1208 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1209 in accordance with Proof General 3.7, which prefers GNU emacs.
  1210 
  1211 * isatool tty runs Isabelle process with plain tty interaction;
  1212 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1213 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1214 
  1215 * isatool browser now works with Cygwin as well, using general
  1216 "javapath" function defined in Isabelle process environment.
  1217 
  1218 * YXML notation provides a simple and efficient alternative to
  1219 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1220 isatool yxml as described in the Isabelle system manual.
  1221 
  1222 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1223 provides general wrapper for managing an Isabelle process in a robust
  1224 fashion, with ``cooked'' output from stdin/stderr.
  1225 
  1226 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1227 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1228 
  1229 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1230 way of changing the user's settings is via
  1231 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1232 script.
  1233 
  1234 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1235 cores of the underlying machine, which is a good starting point for
  1236 optimal performance tuning.  The corresponding usedir option -M allows
  1237 "max" as an alias for "0".  WARNING: does not work on certain versions
  1238 of Mac OS (with Poly/ML 5.1).
  1239 
  1240 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1241 adverse effect of Isabelle flooding interactive front-ends (notably
  1242 ProofGeneral / XEmacs).
  1243 
  1244 
  1245 
  1246 New in Isabelle2007 (November 2007)
  1247 -----------------------------------
  1248 
  1249 *** General ***
  1250 
  1251 * More uniform information about legacy features, notably a
  1252 warning/error of "Legacy feature: ...", depending on the state of the
  1253 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1254 legacy features will disappear eventually.
  1255 
  1256 * Theory syntax: the header format ``theory A = B + C:'' has been
  1257 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1258 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1259 
  1260 * Theory syntax: the old non-Isar theory file format has been
  1261 discontinued altogether.  Note that ML proof scripts may still be used
  1262 with Isar theories; migration is usually quite simple with the ML
  1263 function use_legacy_bindings.  INCOMPATIBILITY.
  1264 
  1265 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1266 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1267 quotes.
  1268 
  1269 * Theory loader: be more serious about observing the static theory
  1270 header specifications (including optional directories), but not the
  1271 accidental file locations of previously successful loads.  The strict
  1272 update policy of former update_thy is now already performed by
  1273 use_thy, so the former has been removed; use_thys updates several
  1274 theories simultaneously, just as 'imports' within a theory header
  1275 specification, but without merging the results.  Potential
  1276 INCOMPATIBILITY: may need to refine theory headers and commands
  1277 ROOT.ML which depend on load order.
  1278 
  1279 * Theory loader: optional support for content-based file
  1280 identification, instead of the traditional scheme of full physical
  1281 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1282 (cf. the system manual).  The new scheme allows to work with
  1283 non-finished theories in persistent session images, such that source
  1284 files may be moved later on without requiring reloads.
  1285 
  1286 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1287 file (with the same base name as the theory) are considered a legacy
  1288 feature, which will disappear eventually. Even now, the theory loader
  1289 no longer maintains dependencies on such files.
  1290 
  1291 * Syntax: the scope for resolving ambiguities via type-inference is
  1292 now limited to individual terms, instead of whole simultaneous
  1293 specifications as before. This greatly reduces the complexity of the
  1294 syntax module and improves flexibility by separating parsing and
  1295 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1296 'fixes' etc.) are required in rare situations.
  1297 
  1298 * Syntax: constants introduced by new-style packages ('definition',
  1299 'abbreviation' etc.) are passed through the syntax module in
  1300 ``authentic mode''. This means that associated mixfix annotations
  1301 really stick to such constants, independently of potential name space
  1302 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1303 trees are represented slightly differently, may need to adapt syntax
  1304 translations accordingly. Use CONST marker in 'translations' and
  1305 @{const_syntax} antiquotation in 'parse_translation' etc.
  1306 
  1307 * Legacy goal package: reduced interface to the bare minimum required
  1308 to keep existing proof scripts running.  Most other user-level
  1309 functions are now part of the OldGoals structure, which is *not* open
  1310 by default (consider isatool expandshort before open OldGoals).
  1311 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1312 these tend to cause confusion about the actual goal (!) context being
  1313 used here, which is not necessarily the same as the_context().
  1314 
  1315 * Command 'find_theorems': supports "*" wild-card in "name:"
  1316 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1317 support a specific search form (see ProofGeneral/CHANGES).
  1318 
  1319 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1320 by default, which means that "prems" (and also "fixed variables") are
  1321 suppressed from proof state output.  Note that the ProofGeneral
  1322 settings mechanism allows to change and save options persistently, but
  1323 older versions of Isabelle will fail to start up if a negative prems
  1324 limit is imposed.
  1325 
  1326 * Local theory targets may be specified by non-nested blocks of
  1327 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1328 contain definitions, theorems etc., including any derived mechanism
  1329 that has been implemented on top of these primitives.  This concept
  1330 generalizes the existing ``theorem (in ...)'' towards more versatility
  1331 and scalability.
  1332 
  1333 * Proof General interface: proper undo of final 'end' command;
  1334 discontinued Isabelle/classic mode (ML proof scripts).
  1335 
  1336 
  1337 *** Document preparation ***
  1338 
  1339 * Added antiquotation @{theory name} which prints the given name,
  1340 after checking that it refers to a valid ancestor theory in the
  1341 current context.
  1342 
  1343 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1344 check the given source text as ML type/structure, printing verbatim.
  1345 
  1346 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1347 "c args == rhs" given in the current context.  (Any number of
  1348 arguments may be given on the LHS.)
  1349 
  1350 
  1351 *** Pure ***
  1352 
  1353 * The 'class' package offers a combination of axclass and locale to
  1354 achieve Haskell-like type classes in Isabelle.  Definitions and
  1355 theorems within a class context produce both relative results (with
  1356 implicit parameters according to the locale context), and polymorphic
  1357 constants with qualified polymorphism (according to the class
  1358 context).  Within the body context of a 'class' target, a separate
  1359 syntax layer ("user space type system") takes care of converting
  1360 between global polymorphic consts and internal locale representation.
  1361 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1362 "isatool doc classes" provides a tutorial.
  1363 
  1364 * Generic code generator framework allows to generate executable
  1365 code for ML and Haskell (including Isabelle classes).  A short usage
  1366 sketch:
  1367 
  1368     internal compilation:
  1369         export_code <list of constants (term syntax)> in SML
  1370     writing SML code to a file:
  1371         export_code <list of constants (term syntax)> in SML <filename>
  1372     writing OCaml code to a file:
  1373         export_code <list of constants (term syntax)> in OCaml <filename>
  1374     writing Haskell code to a bunch of files:
  1375         export_code <list of constants (term syntax)> in Haskell <filename>
  1376 
  1377     evaluating closed propositions to True/False using code generation:
  1378         method ``eval''
  1379 
  1380 Reasonable default setup of framework in HOL.
  1381 
  1382 Theorem attributs for selecting and transforming function equations theorems:
  1383 
  1384     [code fun]:        select a theorem as function equation for a specific constant
  1385     [code fun del]:    deselect a theorem as function equation for a specific constant
  1386     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1387     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1388 
  1389 User-defined serializations (target in {SML, OCaml, Haskell}):
  1390 
  1391     code_const <and-list of constants (term syntax)>
  1392       {(target) <and-list of const target syntax>}+
  1393 
  1394     code_type <and-list of type constructors>
  1395       {(target) <and-list of type target syntax>}+
  1396 
  1397     code_instance <and-list of instances>
  1398       {(target)}+
  1399         where instance ::= <type constructor> :: <class>
  1400 
  1401     code_class <and_list of classes>
  1402       {(target) <and-list of class target syntax>}+
  1403         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1404 
  1405 code_instance and code_class only are effective to target Haskell.
  1406 
  1407 For example usage see src/HOL/ex/Codegenerator.thy and
  1408 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1409 generation from Isabelle/HOL theories is available via "isatool doc
  1410 codegen".
  1411 
  1412 * Code generator: consts in 'consts_code' Isar commands are now
  1413 referred to by usual term syntax (including optional type
  1414 annotations).
  1415 
  1416 * Command 'no_translations' removes translation rules from theory
  1417 syntax.
  1418 
  1419 * Overloaded definitions are now actually checked for acyclic
  1420 dependencies.  The overloading scheme is slightly more general than
  1421 that of Haskell98, although Isabelle does not demand an exact
  1422 correspondence to type class and instance declarations.
  1423 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1424 exotic versions of overloading -- at the discretion of the user!
  1425 
  1426 Polymorphic constants are represented via type arguments, i.e. the
  1427 instantiation that matches an instance against the most general
  1428 declaration given in the signature.  For example, with the declaration
  1429 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1430 as c(nat).  Overloading is essentially simultaneous structural
  1431 recursion over such type arguments.  Incomplete specification patterns
  1432 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1433 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1434 Command 'print_theory' outputs the normalized system of recursive
  1435 equations, see section "definitions".
  1436 
  1437 * Configuration options are maintained within the theory or proof
  1438 context (with name and type bool/int/string), providing a very simple
  1439 interface to a poor-man's version of general context data.  Tools may
  1440 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1441 these values using Config.get etc.  Users may change options via an
  1442 associated attribute of the same name.  This form of context
  1443 declaration works particularly well with commands 'declare' or
  1444 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1445 very easy to avoid global references, which would not observe Isar
  1446 toplevel undo/redo and fail to work with multithreading.
  1447 
  1448 Various global ML references of Pure and HOL have been turned into
  1449 configuration options:
  1450 
  1451   Unify.search_bound		unify_search_bound
  1452   Unify.trace_bound		unify_trace_bound
  1453   Unify.trace_simp		unify_trace_simp
  1454   Unify.trace_types		unify_trace_types
  1455   Simplifier.simp_depth_limit	simp_depth_limit
  1456   Blast.depth_limit		blast_depth_limit
  1457   DatatypeProp.dtK		datatype_distinctness_limit
  1458   fast_arith_neq_limit  	fast_arith_neq_limit
  1459   fast_arith_split_limit	fast_arith_split_limit
  1460 
  1461 * Named collections of theorems may be easily installed as context
  1462 data using the functor NamedThmsFun (see also
  1463 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1464 attributes; there is also a toplevel print command.  This facility is
  1465 just a common case of general context data, which is the preferred way
  1466 for anything more complex than just a list of facts in canonical
  1467 order.
  1468 
  1469 * Isar: command 'declaration' augments a local theory by generic
  1470 declaration functions written in ML.  This enables arbitrary content
  1471 being added to the context, depending on a morphism that tells the
  1472 difference of the original declaration context wrt. the application
  1473 context encountered later on.
  1474 
  1475 * Isar: proper interfaces for simplification procedures.  Command
  1476 'simproc_setup' declares named simprocs (with match patterns, and body
  1477 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1478 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1479 
  1480 * Isar: an extra pair of brackets around attribute declarations
  1481 abbreviates a theorem reference involving an internal dummy fact,
  1482 which will be ignored later --- only the effect of the attribute on
  1483 the background context will persist.  This form of in-place
  1484 declarations is particularly useful with commands like 'declare' and
  1485 'using', for example ``have A using [[simproc a]] by simp''.
  1486 
  1487 * Isar: method "assumption" (and implicit closing of subproofs) now
  1488 takes simple non-atomic goal assumptions into account: after applying
  1489 an assumption as a rule the resulting subgoals are solved by atomic
  1490 assumption steps.  This is particularly useful to finish 'obtain'
  1491 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1492 without referring to the original premise "!!x. P x ==> thesis" in the
  1493 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1494 more permissive.
  1495 
  1496 * Isar: implicit use of prems from the Isar proof context is
  1497 considered a legacy feature.  Common applications like ``have A .''
  1498 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1499 referencing facts explicitly here improves readability and
  1500 maintainability of proof texts.
  1501 
  1502 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1503 the obtained context from the course of reasoning!  For example:
  1504 
  1505   assume "EX x y. A x & B y"   -- "any previous fact"
  1506   then guess x and y by clarify
  1507 
  1508 This technique is potentially adventurous, depending on the facts and
  1509 proof tools being involved here.
  1510 
  1511 * Isar: known facts from the proof context may be specified as literal
  1512 propositions, using ASCII back-quote syntax.  This works wherever
  1513 named facts used to be allowed so far, in proof commands, proof
  1514 methods, attributes etc.  Literal facts are retrieved from the context
  1515 according to unification of type and term parameters.  For example,
  1516 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1517 theorems in the current context, then these are valid literal facts:
  1518 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1519 
  1520 There is also a proof method "fact" which does the same composition
  1521 for explicit goal states, e.g. the following proof texts coincide with
  1522 certain special cases of literal facts:
  1523 
  1524   have "A" by fact                 ==  note `A`
  1525   have "A ==> B" by fact           ==  note `A ==> B`
  1526   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1527   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1528 
  1529 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1530 outer syntax.  Thus symbolic identifiers may be used without
  1531 additional white space in declarations like this: ``assume *: A''.
  1532 
  1533 * Isar: 'print_facts' prints all local facts of the current context,
  1534 both named and unnamed ones.
  1535 
  1536 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1537 
  1538   def x == "t" and y == "u"
  1539 
  1540 * Isar: added command 'unfolding', which is structurally similar to
  1541 'using', but affects both the goal state and facts by unfolding given
  1542 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1543 'unfolded' attribute may be replaced by first-class proof text.
  1544 
  1545 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1546 and command 'unfolding' now all support object-level equalities
  1547 (potentially conditional).  The underlying notion of rewrite rule is
  1548 analogous to the 'rule_format' attribute, but *not* that of the
  1549 Simplifier (which is usually more generous).
  1550 
  1551 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1552 premises of a theorem by n. Useful in conjunction with drule.
  1553 
  1554 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1555 method expression within a sandbox consisting of the first N
  1556 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1557 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1558 simplifies all new goals that emerge from applying rule foo to the
  1559 originally first one.
  1560 
  1561 * Isar: schematic goals are no longer restricted to higher-order
  1562 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1563 expected.
  1564 
  1565 * Isar: the conclusion of a long theorem statement is now either
  1566 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1567 (essentially a disjunction of cases with local parameters and
  1568 assumptions).  The latter allows to express general elimination rules
  1569 adequately; in this notation common elimination rules look like this:
  1570 
  1571   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1572     assumes "EX x. P x"
  1573     obtains x where "P x"
  1574 
  1575   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1576     assumes "A & B"
  1577     obtains A and B
  1578 
  1579   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1580     assumes "A | B"
  1581     obtains
  1582       A
  1583     | B
  1584 
  1585 The subsequent classical rules even refer to the formal "thesis"
  1586 explicitly:
  1587 
  1588   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1589     obtains "~ thesis"
  1590 
  1591   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1592     obtains "thesis ==> something"
  1593 
  1594 The actual proof of an 'obtains' statement is analogous to that of the
  1595 Isar proof element 'obtain', only that there may be several cases.
  1596 Optional case names may be specified in parentheses; these will be
  1597 available both in the present proof and as annotations in the
  1598 resulting rule, for later use with the 'cases' method (cf. attribute
  1599 case_names).
  1600 
  1601 * Isar: the assumptions of a long theorem statement are available as
  1602 "assms" fact in the proof context.  This is more appropriate than the
  1603 (historical) "prems", which refers to all assumptions of the current
  1604 context, including those from the target locale, proof body etc.
  1605 
  1606 * Isar: 'print_statement' prints theorems from the current theory or
  1607 proof context in long statement form, according to the syntax of a
  1608 top-level lemma.
  1609 
  1610 * Isar: 'obtain' takes an optional case name for the local context
  1611 introduction rule (default "that").
  1612 
  1613 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1614 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1615 to occur.
  1616 
  1617 * Pure: syntax "CONST name" produces a fully internalized constant
  1618 according to the current context.  This is particularly useful for
  1619 syntax translations that should refer to internal constant
  1620 representations independently of name spaces.
  1621 
  1622 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1623 instead of "FOO ". This allows multiple binder declarations to coexist
  1624 in the same context.  INCOMPATIBILITY.
  1625 
  1626 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1627 primitive that also works in a locale context (both for constants and
  1628 fixed variables). Type declaration and internal syntactic representation
  1629 of given constants retrieved from the context. Likewise, the
  1630 'no_notation' command allows to remove given syntax annotations from the
  1631 current context.
  1632 
  1633 * Isar/locales: new derived specification elements 'axiomatization',
  1634 'definition', 'abbreviation', which support type-inference, admit
  1635 object-level specifications (equality, equivalence).  See also the
  1636 isar-ref manual.  Examples:
  1637 
  1638   axiomatization
  1639     eq  (infix "===" 50) where
  1640     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1641 
  1642   definition "f x y = x + y + 1"
  1643   definition g where "g x = f x x"
  1644 
  1645   abbreviation
  1646     neq  (infix "=!=" 50) where
  1647     "x =!= y == ~ (x === y)"
  1648 
  1649 These specifications may be also used in a locale context.  Then the
  1650 constants being introduced depend on certain fixed parameters, and the
  1651 constant name is qualified by the locale base name.  An internal
  1652 abbreviation takes care for convenient input and output, making the
  1653 parameters implicit and using the original short name.  See also
  1654 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1655 entities from a monomorphic theory.
  1656 
  1657 Presently, abbreviations are only available 'in' a target locale, but
  1658 not inherited by general import expressions.  Also note that
  1659 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1660 'translations' in common applications.  The "no_abbrevs" print mode
  1661 prevents folding of abbreviations in term output.
  1662 
  1663 Concrete syntax is attached to specified constants in internal form,
  1664 independently of name spaces.  The parse tree representation is
  1665 slightly different -- use 'notation' instead of raw 'syntax', and
  1666 'translations' with explicit "CONST" markup to accommodate this.
  1667 
  1668 * Pure/Isar: unified syntax for new-style specification mechanisms
  1669 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1670 full type inference and dummy patterns ("_").  For example:
  1671 
  1672   definition "K x _ = x"
  1673 
  1674   inductive conj for A B
  1675   where "A ==> B ==> conj A B"
  1676 
  1677 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1678 the current context.  Print mode "no_abbrevs" prevents inversion of
  1679 abbreviations on output.
  1680 
  1681 * Isar/locales: improved parameter handling: use of locales "var" and
  1682 "struct" no longer necessary; - parameter renamings are no longer
  1683 required to be injective.  For example, this allows to define
  1684 endomorphisms as locale endom = homom mult mult h.
  1685 
  1686 * Isar/locales: changed the way locales with predicates are defined.
  1687 Instead of accumulating the specification, the imported expression is
  1688 now an interpretation.  INCOMPATIBILITY: different normal form of
  1689 locale expressions.  In particular, in interpretations of locales with
  1690 predicates, goals repesenting already interpreted fragments are not
  1691 removed automatically.  Use methods `intro_locales' and
  1692 `unfold_locales'; see below.
  1693 
  1694 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1695 provide backward reasoning on locales predicates.  The methods are
  1696 aware of interpretations and discharge corresponding goals.
  1697 `intro_locales' is less aggressive then `unfold_locales' and does not
  1698 unfold predicates to assumptions.
  1699 
  1700 * Isar/locales: the order in which locale fragments are accumulated
  1701 has changed.  This enables to override declarations from fragments due
  1702 to interpretations -- for example, unwanted simp rules.
  1703 
  1704 * Isar/locales: interpretation in theories and proof contexts has been
  1705 extended.  One may now specify (and prove) equations, which are
  1706 unfolded in interpreted theorems.  This is useful for replacing
  1707 defined concepts (constants depending on locale parameters) by
  1708 concepts already existing in the target context.  Example:
  1709 
  1710   interpretation partial_order ["op <= :: [int, int] => bool"]
  1711     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1712 
  1713 Typically, the constant `partial_order.less' is created by a
  1714 definition specification element in the context of locale
  1715 partial_order.
  1716 
  1717 * Method "induct": improved internal context management to support
  1718 local fixes and defines on-the-fly. Thus explicit meta-level
  1719 connectives !!  and ==> are rarely required anymore in inductive goals
  1720 (using object-logic connectives for this purpose has been long
  1721 obsolete anyway). Common proof patterns are explained in
  1722 src/HOL/Induct/Common_Patterns.thy, see also
  1723 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1724 examples.
  1725 
  1726 * Method "induct": improved handling of simultaneous goals. Instead of
  1727 introducing object-level conjunction, the statement is now split into
  1728 several conclusions, while the corresponding symbolic cases are nested
  1729 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1730 see src/HOL/Induct/Common_Patterns.thy, for example.
  1731 
  1732 * Method "induct": mutual induction rules are now specified as a list
  1733 of rule sharing the same induction cases. HOL packages usually provide
  1734 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1735 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1736 mutual induction rules differently, i.e. like this:
  1737 
  1738   (induct rule: foo_bar.inducts)
  1739   (induct set: foo bar)
  1740   (induct pred: foo bar)
  1741   (induct type: foo bar)
  1742 
  1743 The ML function ProjectRule.projections turns old-style rules into the
  1744 new format.
  1745 
  1746 * Method "coinduct": dual of induction, see
  1747 src/HOL/Library/Coinductive_List.thy for various examples.
  1748 
  1749 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1750 considered a legacy feature.
  1751 
  1752 * Attribute "symmetric" produces result with standardized schematic
  1753 variables (index 0).  Potential INCOMPATIBILITY.
  1754 
  1755 * Simplifier: by default the simplifier trace only shows top level
  1756 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1757 default. Thus there is less danger of being flooded by the trace. The
  1758 trace indicates where parts have been suppressed.
  1759   
  1760 * Provers/classical: removed obsolete classical version of elim_format
  1761 attribute; classical elim/dest rules are now treated uniformly when
  1762 manipulating the claset.
  1763 
  1764 * Provers/classical: stricter checks to ensure that supplied intro,
  1765 dest and elim rules are well-formed; dest and elim rules must have at
  1766 least one premise.
  1767 
  1768 * Provers/classical: attributes dest/elim/intro take an optional
  1769 weight argument for the rule (just as the Pure versions).  Weights are
  1770 ignored by automated tools, but determine the search order of single
  1771 rule steps.
  1772 
  1773 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1774 where the body does not mention the bound variable.  Note that dummy
  1775 patterns implicitly depend on their context of bounds, which makes
  1776 "{_. _}" match any set comprehension as expected.  Potential
  1777 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1778 constant "_idtdummy" in the binding position.
  1779 
  1780 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1781 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1782 for example "A -> B" => "Pi A (%_. B)".
  1783 
  1784 * Pure: 'class_deps' command visualizes the subclass relation, using
  1785 the graph browser tool.
  1786 
  1787 * Pure: 'print_theory' now suppresses certain internal declarations by
  1788 default; use '!' option for full details.
  1789 
  1790 
  1791 *** HOL ***
  1792 
  1793 * Method "metis" proves goals by applying the Metis general-purpose
  1794 resolution prover (see also http://gilith.com/software/metis/).
  1795 Examples are in the directory MetisExamples.  WARNING: the
  1796 Isabelle/HOL-Metis integration does not yet work properly with
  1797 multi-threading.
  1798   
  1799 * Command 'sledgehammer' invokes external automatic theorem provers as
  1800 background processes.  It generates calls to the "metis" method if
  1801 successful. These can be pasted into the proof.  Users do not have to
  1802 wait for the automatic provers to return.  WARNING: does not really
  1803 work with multi-threading.
  1804 
  1805 * New "auto_quickcheck" feature tests outermost goal statements for
  1806 potential counter-examples.  Controlled by ML references
  1807 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1808 5000 milliseconds).  Fails silently if statements is outside of
  1809 executable fragment, or any other codgenerator problem occurs.
  1810 
  1811 * New constant "undefined" with axiom "undefined x = undefined".
  1812 
  1813 * Added class "HOL.eq", allowing for code generation with polymorphic
  1814 equality.
  1815 
  1816 * Some renaming of class constants due to canonical name prefixing in
  1817 the new 'class' package:
  1818 
  1819     HOL.abs ~> HOL.abs_class.abs
  1820     HOL.divide ~> HOL.divide_class.divide
  1821     0 ~> HOL.zero_class.zero
  1822     1 ~> HOL.one_class.one
  1823     op + ~> HOL.plus_class.plus
  1824     op - ~> HOL.minus_class.minus
  1825     uminus ~> HOL.minus_class.uminus
  1826     op * ~> HOL.times_class.times
  1827     op < ~> HOL.ord_class.less
  1828     op <= > HOL.ord_class.less_eq
  1829     Nat.power ~> Power.power_class.power
  1830     Nat.size ~> Nat.size_class.size
  1831     Numeral.number_of ~> Numeral.number_class.number_of
  1832     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1833     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1834     Orderings.min ~> Orderings.ord_class.min
  1835     Orderings.max ~> Orderings.ord_class.max
  1836     Divides.op div ~> Divides.div_class.div
  1837     Divides.op mod ~> Divides.div_class.mod
  1838     Divides.op dvd ~> Divides.div_class.dvd
  1839 
  1840 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1841 
  1842 a) User-defined constants using any of the names "plus", "minus",
  1843 "times", "less" or "less_eq". The standard syntax translations for
  1844 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1845 names.
  1846 
  1847 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1848 INCOMPATIBILITY: use more specific names.
  1849 
  1850 c) Permutative equations (e.g. "a + b = b + a")
  1851 Since the change of names also changes the order of terms, permutative
  1852 rewrite rules may get applied in a different order. Experience shows
  1853 that this is rarely the case (only two adaptions in the whole Isabelle
  1854 distribution).  INCOMPATIBILITY: rewrite proofs
  1855 
  1856 d) ML code directly refering to constant names
  1857 This in general only affects hand-written proof tactics, simprocs and
  1858 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1859 Consider using @{const_name} antiquotation.
  1860 
  1861 * New class "default" with associated constant "default".
  1862 
  1863 * Function "sgn" is now overloaded and available on int, real, complex
  1864 (and other numeric types), using class "sgn".  Two possible defs of
  1865 sgn are given as equational assumptions in the classes sgn_if and
  1866 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1867 INCOMPATIBILITY.
  1868 
  1869 * Locale "partial_order" now unified with class "order" (cf. theory
  1870 Orderings), added parameter "less".  INCOMPATIBILITY.
  1871 
  1872 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1873 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1874 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1875 
  1876 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1877 changed order of proof goals in instance proofs.
  1878 
  1879 * The transitivity reasoner for partial and linear orders is set up
  1880 for classes "order" and "linorder".  Instances of the reasoner are available
  1881 in all contexts importing or interpreting the corresponding locales.
  1882 Method "order" invokes the reasoner separately; the reasoner
  1883 is also integrated with the Simplifier as a solver.  Diagnostic
  1884 command 'print_orders' shows the available instances of the reasoner
  1885 in the current context.
  1886 
  1887 * Localized monotonicity predicate in theory "Orderings"; integrated
  1888 lemmas max_of_mono and min_of_mono with this predicate.
  1889 INCOMPATIBILITY.
  1890 
  1891 * Formulation of theorem "dense" changed slightly due to integration
  1892 with new class dense_linear_order.
  1893 
  1894 * Uniform lattice theory development in HOL.
  1895 
  1896     constants "meet" and "join" now named "inf" and "sup"
  1897     constant "Meet" now named "Inf"
  1898 
  1899     classes "meet_semilorder" and "join_semilorder" now named
  1900       "lower_semilattice" and "upper_semilattice"
  1901     class "lorder" now named "lattice"
  1902     class "comp_lat" now named "complete_lattice"
  1903 
  1904     Instantiation of lattice classes allows explicit definitions
  1905     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1906 
  1907   INCOMPATIBILITY.  Theorem renames:
  1908 
  1909     meet_left_le            ~> inf_le1
  1910     meet_right_le           ~> inf_le2
  1911     join_left_le            ~> sup_ge1
  1912     join_right_le           ~> sup_ge2
  1913     meet_join_le            ~> inf_sup_ord
  1914     le_meetI                ~> le_infI
  1915     join_leI                ~> le_supI
  1916     le_meet                 ~> le_inf_iff
  1917     le_join                 ~> ge_sup_conv
  1918     meet_idempotent         ~> inf_idem
  1919     join_idempotent         ~> sup_idem
  1920     meet_comm               ~> inf_commute
  1921     join_comm               ~> sup_commute
  1922     meet_leI1               ~> le_infI1
  1923     meet_leI2               ~> le_infI2
  1924     le_joinI1               ~> le_supI1
  1925     le_joinI2               ~> le_supI2
  1926     meet_assoc              ~> inf_assoc
  1927     join_assoc              ~> sup_assoc
  1928     meet_left_comm          ~> inf_left_commute
  1929     meet_left_idempotent    ~> inf_left_idem
  1930     join_left_comm          ~> sup_left_commute
  1931     join_left_idempotent    ~> sup_left_idem
  1932     meet_aci                ~> inf_aci
  1933     join_aci                ~> sup_aci
  1934     le_def_meet             ~> le_iff_inf
  1935     le_def_join             ~> le_iff_sup
  1936     join_absorp2            ~> sup_absorb2
  1937     join_absorp1            ~> sup_absorb1
  1938     meet_absorp1            ~> inf_absorb1
  1939     meet_absorp2            ~> inf_absorb2
  1940     meet_join_absorp        ~> inf_sup_absorb
  1941     join_meet_absorp        ~> sup_inf_absorb
  1942     distrib_join_le         ~> distrib_sup_le
  1943     distrib_meet_le         ~> distrib_inf_le
  1944 
  1945     add_meet_distrib_left   ~> add_inf_distrib_left
  1946     add_join_distrib_left   ~> add_sup_distrib_left
  1947     is_join_neg_meet        ~> is_join_neg_inf
  1948     is_meet_neg_join        ~> is_meet_neg_sup
  1949     add_meet_distrib_right  ~> add_inf_distrib_right
  1950     add_join_distrib_right  ~> add_sup_distrib_right
  1951     add_meet_join_distribs  ~> add_sup_inf_distribs
  1952     join_eq_neg_meet        ~> sup_eq_neg_inf
  1953     meet_eq_neg_join        ~> inf_eq_neg_sup
  1954     add_eq_meet_join        ~> add_eq_inf_sup
  1955     meet_0_imp_0            ~> inf_0_imp_0
  1956     join_0_imp_0            ~> sup_0_imp_0
  1957     meet_0_eq_0             ~> inf_0_eq_0
  1958     join_0_eq_0             ~> sup_0_eq_0
  1959     neg_meet_eq_join        ~> neg_inf_eq_sup
  1960     neg_join_eq_meet        ~> neg_sup_eq_inf
  1961     join_eq_if              ~> sup_eq_if
  1962 
  1963     mono_meet               ~> mono_inf
  1964     mono_join               ~> mono_sup
  1965     meet_bool_eq            ~> inf_bool_eq
  1966     join_bool_eq            ~> sup_bool_eq
  1967     meet_fun_eq             ~> inf_fun_eq
  1968     join_fun_eq             ~> sup_fun_eq
  1969     meet_set_eq             ~> inf_set_eq
  1970     join_set_eq             ~> sup_set_eq
  1971     meet1_iff               ~> inf1_iff
  1972     meet2_iff               ~> inf2_iff
  1973     meet1I                  ~> inf1I
  1974     meet2I                  ~> inf2I
  1975     meet1D1                 ~> inf1D1
  1976     meet2D1                 ~> inf2D1
  1977     meet1D2                 ~> inf1D2
  1978     meet2D2                 ~> inf2D2
  1979     meet1E                  ~> inf1E
  1980     meet2E                  ~> inf2E
  1981     join1_iff               ~> sup1_iff
  1982     join2_iff               ~> sup2_iff
  1983     join1I1                 ~> sup1I1
  1984     join2I1                 ~> sup2I1
  1985     join1I1                 ~> sup1I1
  1986     join2I2                 ~> sup1I2
  1987     join1CI                 ~> sup1CI
  1988     join2CI                 ~> sup2CI
  1989     join1E                  ~> sup1E
  1990     join2E                  ~> sup2E
  1991 
  1992     is_meet_Meet            ~> is_meet_Inf
  1993     Meet_bool_def           ~> Inf_bool_def
  1994     Meet_fun_def            ~> Inf_fun_def
  1995     Meet_greatest           ~> Inf_greatest
  1996     Meet_lower              ~> Inf_lower
  1997     Meet_set_def            ~> Inf_set_def
  1998 
  1999     Sup_def                 ~> Sup_Inf
  2000     Sup_bool_eq             ~> Sup_bool_def
  2001     Sup_fun_eq              ~> Sup_fun_def
  2002     Sup_set_eq              ~> Sup_set_def
  2003 
  2004     listsp_meetI            ~> listsp_infI
  2005     listsp_meet_eq          ~> listsp_inf_eq
  2006 
  2007     meet_min                ~> inf_min
  2008     join_max                ~> sup_max
  2009 
  2010 * Added syntactic class "size"; overloaded constant "size" now has
  2011 type "'a::size ==> bool"
  2012 
  2013 * Internal reorganisation of `size' of datatypes: size theorems
  2014 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2015 simplification rules by default!); theorems "prod.size" now named
  2016 "*.size".
  2017 
  2018 * Class "div" now inherits from class "times" rather than "type".
  2019 INCOMPATIBILITY.
  2020 
  2021 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2022 Linorder etc.  have disappeared; operations defined in terms of
  2023 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2024 
  2025 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2026 
  2027 * HOL-Word: New extensive library and type for generic, fixed size
  2028 machine words, with arithemtic, bit-wise, shifting and rotating
  2029 operations, reflection into int, nat, and bool lists, automation for
  2030 linear arithmetic (by automatic reflection into nat or int), including
  2031 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2032 arithmetic type classes, supporting automatic simplification of
  2033 numerals on all operations.
  2034 
  2035 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2036 
  2037 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2038 
  2039 * Code generator library theories:
  2040   - Code_Integer represents HOL integers by big integer literals in target
  2041     languages.
  2042   - Code_Char represents HOL characters by character literals in target
  2043     languages.
  2044   - Code_Char_chr like Code_Char, but also offers treatment of character
  2045     codes; includes Code_Integer.
  2046   - Executable_Set allows to generate code for finite sets using lists.
  2047   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2048     denominator).
  2049   - Executable_Real implements a subset of real numbers, namly those
  2050     representable by rational numbers.
  2051   - Efficient_Nat implements natural numbers by integers, which in general will
  2052     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2053     includes Code_Integer.
  2054   - Code_Index provides an additional datatype index which is mapped to
  2055     target-language built-in integers.
  2056   - Code_Message provides an additional datatype message_string which is isomorphic to
  2057     strings; messages are mapped to target-language strings.
  2058 
  2059 * New package for inductive predicates
  2060 
  2061   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2062 
  2063     inductive
  2064       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2065       for z_1 :: U_1 and ... and z_n :: U_m
  2066     where
  2067       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2068     | ...
  2069 
  2070   with full support for type-inference, rather than
  2071 
  2072     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2073 
  2074     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2075     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2076 
  2077     inductive "s z_1 ... z_m"
  2078     intros
  2079       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2080       ...
  2081 
  2082   For backward compatibility, there is a wrapper allowing inductive
  2083   sets to be defined with the new package via
  2084 
  2085     inductive_set
  2086       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2087       for z_1 :: U_1 and ... and z_n :: U_m
  2088     where
  2089       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2090     | ...
  2091 
  2092   or
  2093 
  2094     inductive_set
  2095       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2096       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2097       for z_1 :: U_1 and ... and z_n :: U_m
  2098     where
  2099       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2100     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2101     | ...
  2102 
  2103   if the additional syntax "p ..." is required.
  2104 
  2105   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2106   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2107 
  2108   INCOMPATIBILITIES:
  2109 
  2110   - Since declaration and definition of inductive sets or predicates
  2111     is no longer separated, abbreviations involving the newly
  2112     introduced sets or predicates must be specified together with the
  2113     introduction rules after the 'where' keyword (see above), rather
  2114     than before the actual inductive definition.
  2115 
  2116   - The variables in induction and elimination rules are now
  2117     quantified in the order of their occurrence in the introduction
  2118     rules, rather than in alphabetical order. Since this may break
  2119     some proofs, these proofs either have to be repaired, e.g. by
  2120     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2121     statements of the form
  2122 
  2123       case (rule_i a_i_1 ... a_i_{k_i})
  2124 
  2125     or the old order of quantification has to be restored by explicitly adding
  2126     meta-level quantifiers in the introduction rules, i.e.
  2127 
  2128       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2129 
  2130   - The format of the elimination rules is now
  2131 
  2132       p z_1 ... z_m x_1 ... x_n ==>
  2133         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2134         ==> ... ==> P
  2135 
  2136     for predicates and
  2137 
  2138       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2139         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2140         ==> ... ==> P
  2141 
  2142     for sets rather than
  2143 
  2144       x : s z_1 ... z_m ==>
  2145         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2146         ==> ... ==> P
  2147 
  2148     This may require terms in goals to be expanded to n-tuples
  2149     (e.g. using case_tac or simplification with the split_paired_all
  2150     rule) before the above elimination rule is applicable.
  2151 
  2152   - The elimination or case analysis rules for (mutually) inductive
  2153     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2154     list of rules "p_1_..._p_k.elims" is no longer available.
  2155 
  2156 * New package "function"/"fun" for general recursive functions,
  2157 supporting mutual and nested recursion, definitions in local contexts,
  2158 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2159 for small examples, and the separate tutorial on the function
  2160 package. The old recdef "package" is still available as before, but
  2161 users are encouraged to use the new package.
  2162 
  2163 * Method "lexicographic_order" automatically synthesizes termination
  2164 relations as lexicographic combinations of size measures. 
  2165 
  2166 * Case-expressions allow arbitrary constructor-patterns (including
  2167 "_") and take their order into account, like in functional
  2168 programming.  Internally, this is translated into nested
  2169 case-expressions; missing cases are added and mapped to the predefined
  2170 constant "undefined". In complicated cases printing may no longer show
  2171 the original input but the internal form. Lambda-abstractions allow
  2172 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2173 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2174 variable.
  2175 
  2176 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2177 is an abbreviation for "of_nat :: nat => int". The simplification
  2178 rules for "of_nat" have been changed to work like "int" did
  2179 previously.  Potential INCOMPATIBILITY:
  2180   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2181   - of_nat_diff and of_nat_mult are no longer default simp rules
  2182 
  2183 * Method "algebra" solves polynomial equations over (semi)rings using
  2184 Groebner bases. The (semi)ring structure is defined by locales and the
  2185 tool setup depends on that generic context. Installing the method for
  2186 a specific type involves instantiating the locale and possibly adding
  2187 declarations for computation on the coefficients.  The method is
  2188 already instantiated for natural numbers and for the axiomatic class
  2189 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2190 CALCULEMUS 2007 for the general principles underlying this
  2191 architecture of context-aware proof-tools.
  2192 
  2193 * Method "ferrack" implements quantifier elimination over
  2194 special-purpose dense linear orders using locales (analogous to
  2195 "algebra"). The method is already installed for class
  2196 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2197 rat, etc.
  2198 
  2199 * Former constant "List.op @" now named "List.append".  Use ML
  2200 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2201 circumvent possible incompatibilities when working on ML level.
  2202 
  2203 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2204 
  2205 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2206 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2207 
  2208 * New syntax for Haskell-like list comprehension (input only), eg.
  2209 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2210 
  2211 * The special syntax for function "filter" has changed from [x :
  2212 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2213 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2214 
  2215 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2216 defined on nat only, as an abbreviation for [a..<Suc b]
  2217 INCOMPATIBILITY.
  2218 
  2219 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2220 
  2221 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2222 
  2223 * New lemma collection field_simps (an extension of ring_simps) for
  2224 manipulating (in)equations involving division. Multiplies with all
  2225 denominators that can be proved to be non-zero (in equations) or
  2226 positive/negative (in inequations).
  2227 
  2228 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2229 have been improved and renamed to ring_simps, group_simps and
  2230 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2231 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2232 
  2233 * Theory Library/Commutative_Ring: switched from recdef to function
  2234 package; constants add, mul, pow now curried.  Infix syntax for
  2235 algebraic operations.
  2236 
  2237 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2238 INCOMPATIBILITY.
  2239 
  2240 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2241 INCOMPATIBILITY.
  2242 
  2243 * HOL/records: generalised field-update to take a function on the
  2244 field rather than the new value: r(|A := x|) is translated to A_update
  2245 (K x) r The K-combinator that is internally used is called K_record.
  2246 INCOMPATIBILITY: Usage of the plain update functions has to be
  2247 adapted.
  2248  
  2249 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2250 * x = 0, which are required for a semiring.  Richer structures do not
  2251 inherit from semiring_0 anymore, because this property is a theorem
  2252 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2253 there is more to prove, but this is mostly trivial.
  2254 
  2255 * Class "recpower" is generalized to arbitrary monoids, not just
  2256 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2257 commutativity or semiring properties additionally.
  2258 
  2259 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2260 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2261 better use 'abbreviation'.
  2262 
  2263 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2264 
  2265 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2266 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2267 significant changes for setting up numeral syntax for types:
  2268   - New constants Numeral.pred and Numeral.succ instead
  2269       of former Numeral.bin_pred and Numeral.bin_succ.
  2270   - Use integer operations instead of bin_add, bin_mult and so on.
  2271   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2272   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2273 
  2274 See src/HOL/Integ/IntArith.thy for an example setup.
  2275 
  2276 * Command 'normal_form' computes the normal form of a term that may
  2277 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2278 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2279 heavy-duty computations because the functions are compiled to ML
  2280 first.  Correspondingly, a method "normalization" is provided.  See
  2281 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2282 
  2283 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2284 25 like -->); output depends on the "iff" print_mode, the default is
  2285 "A = B" (with priority 50).
  2286 
  2287 * Relations less (<) and less_eq (<=) are also available on type bool.
  2288 Modified syntax to disallow nesting without explicit parentheses,
  2289 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2290 INCOMPATIBILITY.
  2291 
  2292 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2293 
  2294 * Relation composition operator "op O" now has precedence 75 and binds
  2295 stronger than union and intersection. INCOMPATIBILITY.
  2296 
  2297 * The old set interval syntax "{m..n(}" (and relatives) has been
  2298 removed.  Use "{m..<n}" (and relatives) instead.
  2299 
  2300 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2301 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2302 ``declare [[simproc del: neq]]''.
  2303 
  2304 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2305 True/False.
  2306 
  2307 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2308 
  2309 * Theorem setsum_mult renamed to setsum_right_distrib.
  2310 
  2311 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2312 ``rule'' method.
  2313 
  2314 * Reimplemented methods "sat" and "satx", with several improvements:
  2315 goals no longer need to be stated as "<prems> ==> False", equivalences
  2316 (i.e. "=" on type bool) are handled, variable names of the form
  2317 "lit_<n>" are no longer reserved, significant speedup.
  2318 
  2319 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2320 zChaff is still supported as well.
  2321 
  2322 * 'inductive' and 'datatype': provide projections of mutual rules,
  2323 bundled as foo_bar.inducts;
  2324 
  2325 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2326 Library.
  2327 
  2328 * Library: moved theory Accessible_Part to main HOL.
  2329 
  2330 * Library: added theory Coinductive_List of potentially infinite lists
  2331 as greatest fixed-point.
  2332 
  2333 * Library: added theory AssocList which implements (finite) maps as
  2334 association lists.
  2335 
  2336 * Method "evaluation" solves goals (i.e. a boolean expression)
  2337 efficiently by compiling it to ML.  The goal is "proved" (via an
  2338 oracle) if it evaluates to True.
  2339 
  2340 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2341 also when invoked by the simplifier.  This results in the Simplifier
  2342 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2343 Configuration option fast_arith_split_limit=0 recovers the old
  2344 behavior.
  2345 
  2346 * Support for hex (0x20) and binary (0b1001) numerals.
  2347 
  2348 * New method: reify eqs (t), where eqs are equations for an
  2349 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2350 parameter, computes a term s::'b and a list xs::'a list and proves the
  2351 theorem I xs s = t. This is also known as reification or quoting. The
  2352 resulting theorem is applied to the subgoal to substitute t with I xs
  2353 s.  If t is omitted, the subgoal itself is reified.
  2354 
  2355 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2356 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2357 where f is supposed to be a computable function (in the sense of code
  2358 generattion). The method uses reify to compute s and xs as above then
  2359 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2360 r and finally gets the theorem t = r, which is again applied to the
  2361 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2362 
  2363 * Reflection: Automatic reification now handels binding, an example is
  2364 available in src/HOL/ex/ReflectionEx.thy
  2365 
  2366 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2367 command 'statespace' that is similar to 'record', but introduces an
  2368 abstract specification based on the locale infrastructure instead of
  2369 HOL types.  This leads to extra flexibility in composing state spaces,
  2370 in particular multiple inheritance and renaming of components.
  2371 
  2372 
  2373 *** HOL-Complex ***
  2374 
  2375 * Hyperreal: Functions root and sqrt are now defined on negative real
  2376 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2377 Nonnegativity side conditions have been removed from many lemmas, so
  2378 that more subgoals may now be solved by simplification; potential
  2379 INCOMPATIBILITY.
  2380 
  2381 * Real: new type classes formalize real normed vector spaces and
  2382 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2383 and norm :: 'a => real.
  2384 
  2385 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2386 reals into other types. The overloaded constant Reals :: 'a set is now
  2387 defined as range of_real; potential INCOMPATIBILITY.
  2388 
  2389 * Real: proper support for ML code generation, including 'quickcheck'.
  2390 Reals are implemented as arbitrary precision rationals.
  2391 
  2392 * Hyperreal: Several constants that previously worked only for the
  2393 reals have been generalized, so they now work over arbitrary vector
  2394 spaces. Type annotations may need to be added in some cases; potential
  2395 INCOMPATIBILITY.
  2396 
  2397   Infinitesimal  :: ('a::real_normed_vector) star set
  2398   HFinite        :: ('a::real_normed_vector) star set
  2399   HInfinite      :: ('a::real_normed_vector) star set
  2400   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2401   monad          :: ('a::real_normed_vector) star => 'a star set
  2402   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2403   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2404   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2405   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2406   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2407   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2408   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2409   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2410   sgn            :: 'a::real_normed_vector => 'a
  2411   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2412 
  2413 * Complex: Some complex-specific constants are now abbreviations for
  2414 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2415 hnorm.  Other constants have been entirely removed in favor of the
  2416 polymorphic versions (INCOMPATIBILITY):
  2417 
  2418   approx        <-- capprox
  2419   HFinite       <-- CFinite
  2420   HInfinite     <-- CInfinite
  2421   Infinitesimal <-- CInfinitesimal
  2422   monad         <-- cmonad
  2423   galaxy        <-- cgalaxy
  2424   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2425   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2426   (ns)deriv     <-- (ns)cderiv
  2427 
  2428 
  2429 *** HOL-Algebra ***
  2430 
  2431 * Formalisation of ideals and the quotient construction over rings.
  2432 
  2433 * Order and lattice theory no longer based on records.
  2434 INCOMPATIBILITY.
  2435 
  2436 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2437 greatest_closed.  INCOMPATIBILITY.
  2438 
  2439 * Method algebra is now set up via an attribute.  For examples see
  2440 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2441 of algebraic structures.
  2442 
  2443 * Renamed theory CRing to Ring.
  2444 
  2445 
  2446 *** HOL-Nominal ***
  2447 
  2448 * Substantial, yet incomplete support for nominal datatypes (binding
  2449 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2450 src/HOL/Nominal/Examples.  Prospective users should consult
  2451 http://isabelle.in.tum.de/nominal/
  2452 
  2453 
  2454 *** ML ***
  2455 
  2456 * ML basics: just one true type int, which coincides with IntInf.int
  2457 (even on SML/NJ).
  2458 
  2459 * ML within Isar: antiquotations allow to embed statically-checked
  2460 formal entities in the source, referring to the context available at
  2461 compile-time.  For example:
  2462 
  2463 ML {* @{sort "{zero,one}"} *}
  2464 ML {* @{typ "'a => 'b"} *}
  2465 ML {* @{term "%x. x"} *}
  2466 ML {* @{prop "x == y"} *}
  2467 ML {* @{ctyp "'a => 'b"} *}
  2468 ML {* @{cterm "%x. x"} *}
  2469 ML {* @{cprop "x == y"} *}
  2470 ML {* @{thm asm_rl} *}
  2471 ML {* @{thms asm_rl} *}
  2472 ML {* @{type_name c} *}
  2473 ML {* @{type_syntax c} *}
  2474 ML {* @{const_name c} *}
  2475 ML {* @{const_syntax c} *}
  2476 ML {* @{context} *}
  2477 ML {* @{theory} *}
  2478 ML {* @{theory Pure} *}
  2479 ML {* @{theory_ref} *}
  2480 ML {* @{theory_ref Pure} *}
  2481 ML {* @{simpset} *}
  2482 ML {* @{claset} *}
  2483 ML {* @{clasimpset} *}
  2484 
  2485 The same works for sources being ``used'' within an Isar context.
  2486 
  2487 * ML in Isar: improved error reporting; extra verbosity with
  2488 ML_Context.trace enabled.
  2489 
  2490 * Pure/General/table.ML: the join operations now works via exceptions
  2491 DUP/SAME instead of type option. This is simpler in simple cases, and
  2492 admits slightly more efficient complex applications.
  2493 
  2494 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2495 use Context.generic instead of just theory.
  2496 
  2497 * Pure: datatype Context.generic joins theory/Proof.context and
  2498 provides some facilities for code that works in either kind of
  2499 context, notably GenericDataFun for uniform theory and proof data.
  2500 
  2501 * Pure: simplified internal attribute type, which is now always
  2502 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2503 local (Proof.context) attributes have been discontinued, while
  2504 minimizing code duplication. Thm.rule_attribute and
  2505 Thm.declaration_attribute build canonical attributes; see also structure
  2506 Context for further operations on Context.generic, notably
  2507 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2508 declarations and definitions.
  2509 
  2510 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2511 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2512 init only required for impure data. INCOMPATIBILITY: empty really need
  2513 to be empty (no dependencies on theory content!)
  2514 
  2515 * Pure/kernel: consts certification ignores sort constraints given in
  2516 signature declarations. (This information is not relevant to the
  2517 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2518 potential INCOMPATIBILITY.
  2519 
  2520 * Pure: axiomatic type classes are now purely definitional, with
  2521 explicit proofs of class axioms and super class relations performed
  2522 internally. See Pure/axclass.ML for the main internal interfaces --
  2523 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2524 AxClass.axiomatize_class/classrel/arity supersede
  2525 Sign.add_classes/classrel/arities.
  2526 
  2527 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2528 global/local versions on theory vs. Proof.context have been
  2529 discontinued; Attrib.syntax and Method.syntax have been adapted
  2530 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2531 attributes, methods, etc.
  2532 
  2533 * Pure: several functions of signature "... -> theory -> theory * ..."
  2534 have been reoriented to "... -> theory -> ... * theory" in order to
  2535 allow natural usage in combination with the ||>, ||>>, |-> and
  2536 fold_map combinators.
  2537 
  2538 * Pure: official theorem names (closed derivations) and additional
  2539 comments (tags) are now strictly separate.  Name hints -- which are
  2540 maintained as tags -- may be attached any time without affecting the
  2541 derivation.
  2542 
  2543 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2544 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2545 achieve the old behaviour.
  2546 
  2547 * Pure: the "Goal" constant is now called "prop", supporting a
  2548 slightly more general idea of ``protecting'' meta-level rule
  2549 statements.
  2550 
  2551 * Pure: Logic.(un)varify only works in a global context, which is now
  2552 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2553 Logic.legacy_(un)varify as temporary workaround.
  2554 
  2555 * Pure: structure Name provides scalable operations for generating
  2556 internal variable names, notably Name.variants etc.  This replaces
  2557 some popular functions from term.ML:
  2558 
  2559   Term.variant		->  Name.variant
  2560   Term.variantlist	->  Name.variant_list
  2561   Term.invent_names	->  Name.invent_list
  2562 
  2563 Note that low-level renaming rarely occurs in new code -- operations
  2564 from structure Variable are used instead (see below).
  2565 
  2566 * Pure: structure Variable provides fundamental operations for proper
  2567 treatment of fixed/schematic variables in a context.  For example,
  2568 Variable.import introduces fixes for schematics of given facts and
  2569 Variable.export reverses the effect (up to renaming) -- this replaces
  2570 various freeze_thaw operations.
  2571 
  2572 * Pure: structure Goal provides simple interfaces for
  2573 init/conclude/finish and tactical prove operations (replacing former
  2574 Tactic.prove).  Goal.prove is the canonical way to prove results
  2575 within a given context; Goal.prove_global is a degraded version for
  2576 theory level goals, including a global Drule.standard.  Note that
  2577 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2578 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2579 in a locale context).
  2580 
  2581 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2582 and type checking (Syntax.check_term etc.), with common combinations
  2583 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2584 which are considered legacy and await removal.
  2585 
  2586 * Pure/Syntax: generic interfaces for type unchecking
  2587 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2588 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2589 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2590 available for convenience, but refer to the very same operations using
  2591 a mere theory instead of a full context.
  2592 
  2593 * Isar: simplified treatment of user-level errors, using exception
  2594 ERROR of string uniformly.  Function error now merely raises ERROR,
  2595 without any side effect on output channels.  The Isar toplevel takes
  2596 care of proper display of ERROR exceptions.  ML code may use plain
  2597 handle/can/try; cat_error may be used to concatenate errors like this:
  2598 
  2599   ... handle ERROR msg => cat_error msg "..."
  2600 
  2601 Toplevel ML code (run directly or through the Isar toplevel) may be
  2602 embedded into the Isar toplevel with exception display/debug like
  2603 this:
  2604 
  2605   Isar.toplevel (fn () => ...)
  2606 
  2607 INCOMPATIBILITY, removed special transform_error facilities, removed
  2608 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2609 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2610 -- use plain ERROR instead.
  2611 
  2612 * Isar: theory setup now has type (theory -> theory), instead of a
  2613 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2614 
  2615 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2616 ProofContext.debug/verbose flags.
  2617 
  2618 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2619 theory before entering a proof state.  Transactions now always see a
  2620 quasi-functional intermediate checkpoint, both in interactive and
  2621 batch mode.
  2622 
  2623 * Isar: simplified interfaces for outer syntax.  Renamed
  2624 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2625 OuterSyntax.add_parsers -- this functionality is now included in
  2626 OuterSyntax.command etc.  INCOMPATIBILITY.
  2627 
  2628 * Simplifier: the simpset of a running simplification process now
  2629 contains a proof context (cf. Simplifier.the_context), which is the
  2630 very context that the initial simpset has been retrieved from (by
  2631 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2632 (solver, looper etc.) may depend on arbitrary proof data.
  2633 
  2634 * Simplifier.inherit_context inherits the proof context (plus the
  2635 local bounds) of the current simplification process; any simproc
  2636 etc. that calls the Simplifier recursively should do this!  Removed
  2637 former Simplifier.inherit_bounds, which is already included here --
  2638 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2639 specify an explicit context using Simplifier.context/theory_context.
  2640 
  2641 * Simplifier/Classical Reasoner: more abstract interfaces
  2642 change_simpset/claset for modifying the simpset/claset reference of a
  2643 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2644 INCOMPATIBILITY.
  2645 
  2646 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2647 "Trueprop" etc.
  2648 
  2649 
  2650 *** System ***
  2651 
  2652 * settings: the default heap location within ISABELLE_HOME_USER now
  2653 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2654 Isabelle installations.
  2655 
  2656 * isabelle-process: option -S (secure mode) disables some critical
  2657 operations, notably runtime compilation and evaluation of ML source
  2658 code.
  2659 
  2660 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2661 
  2662 * Support for parallel execution, using native multicore support of
  2663 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2664 independent theories, according to the given theory header
  2665 specifications. The maximum number of worker threads is specified via
  2666 usedir option -M or the "max-threads" setting in Proof General. A
  2667 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2668 to 6 on a 8-core machine.  User-code needs to observe certain
  2669 guidelines for thread-safe programming, see appendix A in the Isar
  2670 Implementation manual.
  2671 
  2672 
  2673 
  2674 New in Isabelle2005 (October 2005)
  2675 ----------------------------------
  2676 
  2677 *** General ***
  2678 
  2679 * Theory headers: the new header syntax for Isar theories is
  2680 
  2681   theory <name>
  2682   imports <theory1> ... <theoryN>
  2683   uses <file1> ... <fileM>
  2684   begin
  2685 
  2686 where the 'uses' part is optional.  The previous syntax
  2687 
  2688   theory <name> = <theory1> + ... + <theoryN>:
  2689 
  2690 will disappear in the next release.  Use isatool fixheaders to convert
  2691 existing theory files.  Note that there is no change in ancient
  2692 non-Isar theories now, but these will disappear soon.
  2693 
  2694 * Theory loader: parent theories can now also be referred to via
  2695 relative and absolute paths.
  2696 
  2697 * Command 'find_theorems' searches for a list of criteria instead of a
  2698 list of constants. Known criteria are: intro, elim, dest, name:string,
  2699 simp:term, and any term. Criteria can be preceded by '-' to select
  2700 theorems that do not match. Intro, elim, dest select theorems that
  2701 match the current goal, name:s selects theorems whose fully qualified
  2702 name contain s, and simp:term selects all simplification rules whose
  2703 lhs match term.  Any other term is interpreted as pattern and selects
  2704 all theorems matching the pattern. Available in ProofGeneral under
  2705 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2706 
  2707   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2708 
  2709 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2710 matching the current goal as introduction rule and not having "HOL."
  2711 in their name (i.e. not being defined in theory HOL).
  2712 
  2713 * Command 'thms_containing' has been discontinued in favour of
  2714 'find_theorems'; INCOMPATIBILITY.
  2715 
  2716 * Communication with Proof General is now 8bit clean, which means that
  2717 Unicode text in UTF-8 encoding may be used within theory texts (both
  2718 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2719 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2720 
  2721   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2722   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2723 
  2724 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2725 Classical Reasoner.  Typical big applications run around 2 times
  2726 faster.
  2727 
  2728 
  2729 *** Document preparation ***
  2730 
  2731 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2732 of raw sources.  Only those symbols that do not require additional
  2733 LaTeX packages (depending on comments in isabellesym.sty) are
  2734 displayed properly, everything else is left verbatim.  isatool display
  2735 and isatool print are used as front ends (these are subject to the
  2736 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2737 
  2738 * Command tags control specific markup of certain regions of text,
  2739 notably folding and hiding.  Predefined tags include "theory" (for
  2740 theory begin and end), "proof" for proof commands, and "ML" for
  2741 commands involving ML code; the additional tags "visible" and
  2742 "invisible" are unused by default.  Users may give explicit tag
  2743 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2744 interpretation of tags is determined by the LaTeX job during document
  2745 preparation: see option -V of isatool usedir, or options -n and -t of
  2746 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2747 \isadroptag.
  2748 
  2749 Several document versions may be produced at the same time via isatool
  2750 usedir (the generated index.html will link all of them).  Typical
  2751 specifications include ''-V document=theory,proof,ML'' to present
  2752 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2753 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2754 these parts without any formal replacement text.  The Isabelle site
  2755 default settings produce ''document'' and ''outline'' versions as
  2756 specified above.
  2757 
  2758 * Several new antiquotations:
  2759 
  2760   @{term_type term} prints a term with its type annotated;
  2761 
  2762   @{typeof term} prints the type of a term;
  2763 
  2764   @{const const} is the same as @{term const}, but checks that the
  2765   argument is a known logical constant;
  2766 
  2767   @{term_style style term} and @{thm_style style thm} print a term or
  2768   theorem applying a "style" to it
  2769 
  2770   @{ML text}
  2771 
  2772 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2773 definitions, equations, inequations etc., 'concl' printing only the
  2774 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2775 to print the specified premise.  TermStyle.add_style provides an ML
  2776 interface for introducing further styles.  See also the "LaTeX Sugar"
  2777 document practical applications.  The ML antiquotation prints
  2778 type-checked ML expressions verbatim.
  2779 
  2780 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2781 and 'text' support optional locale specification '(in loc)', which
  2782 specifies the default context for interpreting antiquotations.  For
  2783 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2784 
  2785 * Option 'locale=NAME' of antiquotations specifies an alternative
  2786 context interpreting the subsequent argument.  For example: @{thm
  2787 [locale=lattice] inf_assoc}.
  2788 
  2789 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2790 a proof context.
  2791 
  2792 * Proper output of antiquotations for theory commands involving a
  2793 proof context (such as 'locale' or 'theorem (in loc) ...').
  2794 
  2795 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2796 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2797 
  2798 * isatool usedir: new option -C (default true) controls whether option
  2799 -D should include a copy of the original document directory; -C false
  2800 prevents unwanted effects such as copying of administrative CVS data.
  2801 
  2802 
  2803 *** Pure ***
  2804 
  2805 * Considerably improved version of 'constdefs' command.  Now performs
  2806 automatic type-inference of declared constants; additional support for
  2807 local structure declarations (cf. locales and HOL records), see also
  2808 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2809 sequential dependencies of definitions within a single 'constdefs'
  2810 section; moreover, the declared name needs to be an identifier.  If
  2811 all fails, consider to fall back on 'consts' and 'defs' separately.
  2812 
  2813 * Improved indexed syntax and implicit structures.  First of all,
  2814 indexed syntax provides a notational device for subscripted
  2815 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2816 expressions.  Secondly, in a local context with structure
  2817 declarations, number indexes \<^sub>n or the empty index (default
  2818 number 1) refer to a certain fixed variable implicitly; option
  2819 show_structs controls printing of implicit structures.  Typical
  2820 applications of these concepts involve record types and locales.
  2821 
  2822 * New command 'no_syntax' removes grammar declarations (and
  2823 translations) resulting from the given syntax specification, which is
  2824 interpreted in the same manner as for the 'syntax' command.
  2825 
  2826 * 'Advanced' translation functions (parse_translation etc.) may depend
  2827 on the signature of the theory context being presently used for
  2828 parsing/printing, see also isar-ref manual.
  2829 
  2830 * Improved 'oracle' command provides a type-safe interface to turn an
  2831 ML expression of type theory -> T -> term into a primitive rule of
  2832 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2833 is already included here); see also FOL/ex/IffExample.thy;
  2834 INCOMPATIBILITY.
  2835 
  2836 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2837 before); "cI" is no longer bound, use "c.intro" instead.
  2838 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2839 axclasses vs. locales.
  2840 
  2841 * Improved internal renaming of symbolic identifiers -- attach primes
  2842 instead of base 26 numbers.
  2843 
  2844 * New flag show_question_marks controls printing of leading question
  2845 marks in schematic variable names.
  2846 
  2847 * In schematic variable names, *any* symbol following \<^isub> or
  2848 \<^isup> is now treated as part of the base name.  For example, the
  2849 following works without printing of awkward ".0" indexes:
  2850 
  2851   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2852     by simp
  2853 
  2854 * Inner syntax includes (*(*nested*) comments*).
  2855 
  2856 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2857 annotations as "(00...)".
  2858 
  2859 * Clear separation of logical types and nonterminals, where the latter
  2860 may only occur in 'syntax' specifications or type abbreviations.
  2861 Before that distinction was only partially implemented via type class
  2862 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2863 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2864 exotic syntax specifications may require further adaption
  2865 (e.g. Cube/Cube.thy).
  2866 
  2867 * Removed obsolete type class "logic", use the top sort {} instead.
  2868 Note that non-logical types should be declared as 'nonterminals'
  2869 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2870 specifications.
  2871 
  2872 * Attributes 'induct' and 'cases': type or set names may now be
  2873 locally fixed variables as well.
  2874 
  2875 * Simplifier: can now control the depth to which conditional rewriting
  2876 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2877 Limit.
  2878 
  2879 * Simplifier: simplification procedures may now take the current
  2880 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2881 interface), which is very useful for calling the Simplifier
  2882 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2883 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2884 low-level mk_simproc no longer applies Logic.varify internally, to
  2885 allow for use in a context of fixed variables.
  2886 
  2887 * thin_tac now works even if the assumption being deleted contains !!
  2888 or ==>.  More generally, erule now works even if the major premise of
  2889 the elimination rule contains !! or ==>.
  2890 
  2891 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2892 
  2893 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2894 from Pure, which contains all common declarations already.  Both
  2895 theories are defined via plain Isabelle/Isar .thy files.
  2896 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2897 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2898 use isatool fixcpure to adapt your theory and ML sources.
  2899 
  2900 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2901 selections of theorems in named facts via index ranges.
  2902 
  2903 * 'print_theorems': in theory mode, really print the difference
  2904 wrt. the last state (works for interactive theory development only),
  2905 in proof mode print all local facts (cf. 'print_facts');
  2906 
  2907 * 'hide': option '(open)' hides only base names.
  2908 
  2909 * More efficient treatment of intermediate checkpoints in interactive
  2910 theory development.
  2911 
  2912 * Code generator is now invoked via code_module (incremental code
  2913 generation) and code_library (modular code generation, ML structures
  2914 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2915 must be quoted when used as identifiers.
  2916 
  2917 * New 'value' command for reading, evaluating and printing terms using
  2918 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  2919 quoted when used as identifier.
  2920 
  2921 
  2922 *** Locales ***
  2923 
  2924 * New commands for the interpretation of locale expressions in
  2925 theories (1), locales (2) and proof contexts (3).  These generate
  2926 proof obligations from the expression specification.  After the
  2927 obligations have been discharged, theorems of the expression are added
  2928 to the theory, target locale or proof context.  The synopsis of the
  2929 commands is a follows:
  2930 
  2931   (1) interpretation expr inst
  2932   (2) interpretation target < expr
  2933   (3) interpret expr inst
  2934 
  2935 Interpretation in theories and proof contexts require a parameter
  2936 instantiation of terms from the current context.  This is applied to
  2937 specifications and theorems of the interpreted expression.
  2938 Interpretation in locales only permits parameter renaming through the
  2939 locale expression.  Interpretation is smart in that interpretations
  2940 that are active already do not occur in proof obligations, neither are
  2941 instantiated theorems stored in duplicate.  Use 'print_interps' to
  2942 inspect active interpretations of a particular locale.  For details,
  2943 see the Isar Reference manual.  Examples can be found in
  2944 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  2945 
  2946 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  2947 'interpret' instead.
  2948 
  2949 * New context element 'constrains' for adding type constraints to
  2950 parameters.
  2951 
  2952 * Context expressions: renaming of parameters with syntax
  2953 redeclaration.
  2954 
  2955 * Locale declaration: 'includes' disallowed.
  2956 
  2957 * Proper static binding of attribute syntax -- i.e. types / terms /
  2958 facts mentioned as arguments are always those of the locale definition
  2959 context, independently of the context of later invocations.  Moreover,
  2960 locale operations (renaming and type / term instantiation) are applied
  2961 to attribute arguments as expected.
  2962 
  2963 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  2964 actual attributes; rare situations may require Attrib.attribute to
  2965 embed those attributes into Attrib.src that lack concrete syntax.
  2966 Attribute implementations need to cooperate properly with the static
  2967 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  2968 Attrib.XXX_thm etc. already do the right thing without further
  2969 intervention.  Only unusual applications -- such as "where" or "of"
  2970 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  2971 on the context and the facts involved -- may have to assign parsed
  2972 values to argument tokens explicitly.
  2973 
  2974 * Changed parameter management in theorem generation for long goal
  2975 statements with 'includes'.  INCOMPATIBILITY: produces a different
  2976 theorem statement in rare situations.
  2977 
  2978 * Locale inspection command 'print_locale' omits notes elements.  Use
  2979 'print_locale!' to have them included in the output.
  2980 
  2981 
  2982 *** Provers ***
  2983 
  2984 * Provers/hypsubst.ML: improved version of the subst method, for
  2985 single-step rewriting: it now works in bound variable contexts. New is
  2986 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  2987 rewrite a different subterm than the original subst method, which is
  2988 still available as 'simplesubst'.
  2989 
  2990 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  2991 and quasi orders.
  2992 
  2993 * Provers/trancl.ML: new transitivity reasoner for transitive and
  2994 reflexive-transitive closure of relations.
  2995 
  2996 * Provers/blast.ML: new reference depth_limit to make blast's depth
  2997 limit (previously hard-coded with a value of 20) user-definable.
  2998 
  2999 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3000 is peformed already.  Object-logics merely need to finish their
  3001 initial simpset configuration as before.  INCOMPATIBILITY.
  3002 
  3003 
  3004 *** HOL ***
  3005 
  3006 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3007 
  3008   syntax (epsilon)
  3009     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3010 
  3011 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3012 and x-symbol; use option '-m epsilon' to get it actually printed.
  3013 Moreover, the mathematically important symbolic identifier \<epsilon>
  3014 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3015 
  3016 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3017 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3018 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3019 support corresponding Isar calculations.
  3020 
  3021 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3022 instead of ":".
  3023 
  3024 * theory SetInterval: changed the syntax for open intervals:
  3025 
  3026   Old       New
  3027   {..n(}    {..<n}
  3028   {)n..}    {n<..}
  3029   {m..n(}   {m..<n}
  3030   {)m..n}   {m<..n}
  3031   {)m..n(}  {m<..<n}
  3032 
  3033 The old syntax is still supported but will disappear in the next
  3034 release.  For conversion use the following Emacs search and replace
  3035 patterns (these are not perfect but work quite well):
  3036 
  3037   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3038   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3039 
  3040 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3041 equalities in commutative rings; method 'algebra' provides a generic
  3042 interface.
  3043 
  3044 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3045 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3046 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3047 be a tuple pattern.
  3048 
  3049 Some new syntax forms are available:
  3050 
  3051   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3052   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3053   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3054   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3055 
  3056 The latter form "\<Sum>x < k. e" used to be based on a separate
  3057 function "Summation", which has been discontinued.
  3058 
  3059 * theory Finite_Set: in structured induction proofs, the insert case
  3060 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3061 (insert F x)'.
  3062 
  3063 * The 'refute' command has been extended to support a much larger
  3064 fragment of HOL, including axiomatic type classes, constdefs and
  3065 typedefs, inductive datatypes and recursion.
  3066 
  3067 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3068 Requires zChaff with proof generation to be installed.  See
  3069 HOL/ex/SAT_Examples.thy for examples.
  3070 
  3071 * Datatype induction via method 'induct' now preserves the name of the
  3072 induction variable. For example, when proving P(xs::'a list) by
  3073 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3074 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3075 in unstructured proof scripts.
  3076 
  3077 * Reworked implementation of records.  Improved scalability for
  3078 records with many fields, avoiding performance problems for type
  3079 inference. Records are no longer composed of nested field types, but
  3080 of nested extension types. Therefore the record type only grows linear
  3081 in the number of extensions and not in the number of fields.  The
  3082 top-level (users) view on records is preserved.  Potential
  3083 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3084 old record representation. The type generated for a record is called
  3085 <record_name>_ext_type.
  3086 
  3087 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3088 proofs triggered by a record definition or a simproc (if
  3089 quick_and_dirty is enabled).  Definitions of large records can take
  3090 quite long.
  3091 
  3092 New simproc record_upd_simproc for simplification of multiple record
  3093 updates enabled by default.  Moreover, trivial updates are also
  3094 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3095 occasionally, since simplification is more powerful by default.
  3096 
  3097 * typedef: proper support for polymorphic sets, which contain extra
  3098 type-variables in the term.
  3099 
  3100 * Simplifier: automatically reasons about transitivity chains
  3101 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3102 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3103 old proofs break occasionally as simplification may now solve more
  3104 goals than previously.
  3105 
  3106 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3107 present.  Works for all partial orders (class "order"), in particular
  3108 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3109 just like y <= x.
  3110 
  3111 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3112 bound variable or a constant then the let is unfolded.  Otherwise
  3113 first a is simplified to b, and then f b is simplified to g. If
  3114 possible we abstract b from g arriving at "let x = b in h x",
  3115 otherwise we unfold the let and arrive at g.  The simproc can be
  3116 enabled/disabled by the reference use_let_simproc.  Potential
  3117 INCOMPATIBILITY since simplification is more powerful by default.
  3118 
  3119 * Classical reasoning: the meson method now accepts theorems as arguments.
  3120 
  3121 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3122 jobs to provide advice on the provability of subgoals.
  3123 
  3124 * Theory OrderedGroup and Ring_and_Field: various additions and
  3125 improvements to faciliate calculations involving equalities and
  3126 inequalities.
  3127 
  3128 The following theorems have been eliminated or modified
  3129 (INCOMPATIBILITY):
  3130 
  3131   abs_eq             now named abs_of_nonneg
  3132   abs_of_ge_0        now named abs_of_nonneg
  3133   abs_minus_eq       now named abs_of_nonpos
  3134   imp_abs_id         now named abs_of_nonneg
  3135   imp_abs_neg_id     now named abs_of_nonpos
  3136   mult_pos           now named mult_pos_pos
  3137   mult_pos_le        now named mult_nonneg_nonneg
  3138   mult_pos_neg_le    now named mult_nonneg_nonpos
  3139   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3140   mult_neg           now named mult_neg_neg
  3141   mult_neg_le        now named mult_nonpos_nonpos
  3142 
  3143 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3144      
  3145      zero_le_square
  3146      not_square_less_zero 
  3147 
  3148   The following lemmas have been deleted from Real/RealPow:
  3149   
  3150      realpow_zero_zero
  3151      realpow_two
  3152      realpow_less
  3153      zero_le_power
  3154      realpow_two_le
  3155      abs_realpow_two
  3156      realpow_two_abs     
  3157 
  3158 * Theory Parity: added rules for simplifying exponents.
  3159 
  3160 * Theory List:
  3161 
  3162 The following theorems have been eliminated or modified
  3163 (INCOMPATIBILITY):
  3164 
  3165   list_all_Nil       now named list_all.simps(1)
  3166   list_all_Cons      now named list_all.simps(2)
  3167   list_all_conv      now named list_all_iff
  3168   set_mem_eq         now named mem_iff
  3169 
  3170 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3171 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3172 
  3173 
  3174 *** HOL-Complex ***
  3175 
  3176 * Theory RealDef: better support for embedding natural numbers and
  3177 integers in the reals.
  3178 
  3179 The following theorems have been eliminated or modified
  3180 (INCOMPATIBILITY):
  3181 
  3182   exp_ge_add_one_self  now requires no hypotheses
  3183   real_of_int_add      reversed direction of equality (use [symmetric])
  3184   real_of_int_minus    reversed direction of equality (use [symmetric])
  3185   real_of_int_diff     reversed direction of equality (use [symmetric])
  3186   real_of_int_mult     reversed direction of equality (use [symmetric])
  3187 
  3188 * Theory RComplete: expanded support for floor and ceiling functions.
  3189 
  3190 * Theory Ln is new, with properties of the natural logarithm
  3191 
  3192 * Hyperreal: There is a new type constructor "star" for making
  3193 nonstandard types.  The old type names are now type synonyms:
  3194 
  3195   hypreal = real star
  3196   hypnat = nat star
  3197   hcomplex = complex star
  3198 
  3199 * Hyperreal: Many groups of similarly-defined constants have been
  3200 replaced by polymorphic versions (INCOMPATIBILITY):
  3201 
  3202   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3203 
  3204   starset      <-- starsetNat, starsetC
  3205   *s*          <-- *sNat*, *sc*
  3206   starset_n    <-- starsetNat_n, starsetC_n
  3207   *sn*         <-- *sNatn*, *scn*
  3208   InternalSets <-- InternalNatSets, InternalCSets
  3209 
  3210   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3211   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3212   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3213   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3214   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3215 
  3216 * Hyperreal: Many type-specific theorems have been removed in favor of
  3217 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3218 
  3219   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3220   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3221   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3222   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3223   right_minus <-- hypreal_add_minus
  3224   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3225   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3226   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3227   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3228   mult_1_right <-- hcomplex_mult_one_right
  3229   mult_zero_left <-- hcomplex_mult_zero_left
  3230   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3231   right_distrib <-- hypnat_add_mult_distrib2
  3232   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3233   right_inverse <-- hypreal_mult_inverse
  3234   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3235   order_refl <-- {hypreal,hypnat}_le_refl
  3236   order_trans <-- {hypreal,hypnat}_le_trans
  3237   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3238   order_less_le <-- {hypreal,hypnat}_less_le
  3239   linorder_linear <-- {hypreal,hypnat}_le_linear
  3240   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3241   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3242   add_nonneg_nonneg <-- hypreal_le_add_order
  3243 
  3244 * Hyperreal: Separate theorems having to do with type-specific
  3245 versions of constants have been merged into theorems that apply to the
  3246 new polymorphic constants (INCOMPATIBILITY):
  3247 
  3248   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3249   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3250   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3251   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3252   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3253   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3254   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3255   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3256   STAR_diff <-- {STAR,STARC}_diff
  3257   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3258     STARC_hcomplex_of_complex}_image_subset
  3259   starset_n_Un <-- starset{Nat,C}_n_Un
  3260   starset_n_Int <-- starset{Nat,C}_n_Int
  3261   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3262   starset_n_diff <-- starset{Nat,C}_n_diff
  3263   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3264   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3265   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3266   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3267   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3268   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3269   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3270   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3271   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3272   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3273   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3274   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3275   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3276   starfun_diff <-- starfun{C,RC,CR}_diff
  3277   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3278   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3279   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3280   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3281   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3282   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3283   starfun_Id <-- starfunC_Id
  3284   starfun_approx <-- starfun{Nat,CR}_approx
  3285   starfun_capprox <-- starfun{C,RC}_capprox
  3286   starfun_abs <-- starfunNat_rabs
  3287   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3288   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3289   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3290   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3291   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3292   starfun_add_approx <-- starfunCR_add_approx
  3293   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3294   starfun_divide <-- starfun{C,CR,RC}_divide
  3295   starfun_n <-- starfun{Nat,C}_n
  3296   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3297   starfun_n_add <-- starfun{Nat,C}_n_add
  3298   starfun_n_add_minus <-- starfunNat_n_add_minus
  3299   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3300   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3301   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3302 
  3303   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3304   star_n_minus <-- {hypreal,hcomplex}_minus
  3305   star_n_diff <-- {hypreal,hcomplex}_diff
  3306   star_n_mult <-- {hypreal,hcomplex}_mult
  3307   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3308   star_n_le <-- {hypreal,hypnat}_le
  3309   star_n_less <-- {hypreal,hypnat}_less
  3310   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3311   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3312   star_n_abs <-- hypreal_hrabs
  3313   star_n_divide <-- hcomplex_divide
  3314 
  3315   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3316   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3317   star_of_diff <-- hypreal_of_real_diff
  3318   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3319   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3320   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3321   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3322   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3323   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3324   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3325   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3326   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3327   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3328   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3329   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3330   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3331   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3332   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3333   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3334   star_of_power <-- hypreal_of_real_power
  3335   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3336 
  3337 * Hyperreal: new method "transfer" that implements the transfer
  3338 principle of nonstandard analysis. With a subgoal that mentions
  3339 nonstandard types like "'a star", the command "apply transfer"
  3340 replaces it with an equivalent one that mentions only standard types.
  3341 To be successful, all free variables must have standard types; non-
  3342 standard variables must have explicit universal quantifiers.
  3343 
  3344 * Hyperreal: A theory of Taylor series.
  3345 
  3346 
  3347 *** HOLCF ***
  3348 
  3349 * Discontinued special version of 'constdefs' (which used to support
  3350 continuous functions) in favor of the general Pure one with full
  3351 type-inference.
  3352 
  3353 * New simplification procedure for solving continuity conditions; it
  3354 is much faster on terms with many nested lambda abstractions (cubic
  3355 instead of exponential time).
  3356 
  3357 * New syntax for domain package: selector names are now optional.
  3358 Parentheses should be omitted unless argument is lazy, for example:
  3359 
  3360   domain 'a stream = cons "'a" (lazy "'a stream")
  3361 
  3362 * New command 'fixrec' for defining recursive functions with pattern
  3363 matching; defining multiple functions with mutual recursion is also
  3364 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3365 sinr, or any data constructor defined by the domain package. The given
  3366 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3367 syntax and examples.
  3368 
  3369 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3370 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3371 but the proof obligation additionally includes an admissibility
  3372 requirement. The packages generate instances of class cpo or pcpo,
  3373 with continuity and strictness theorems for Rep and Abs.
  3374 
  3375 * HOLCF: Many theorems have been renamed according to a more standard naming
  3376 scheme (INCOMPATIBILITY):
  3377 
  3378   foo_inject:  "foo$x = foo$y ==> x = y"
  3379   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3380   foo_less:    "(foo$x << foo$y) = (x << y)"
  3381   foo_strict:  "foo$UU = UU"
  3382   foo_defined: "... ==> foo$x ~= UU"
  3383   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3384 
  3385 
  3386 *** ZF ***
  3387 
  3388 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3389 including the First Isomorphism Theorem (on quotienting by the kernel
  3390 of a homomorphism).
  3391 
  3392 * ZF/Simplifier: install second copy of type solver that actually
  3393 makes use of TC rules declared to Isar proof contexts (or locales);
  3394 the old version is still required for ML proof scripts.
  3395 
  3396 
  3397 *** Cube ***
  3398 
  3399 * Converted to Isar theory format; use locales instead of axiomatic
  3400 theories.
  3401 
  3402 
  3403 *** ML ***
  3404 
  3405 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3406 for ||>, ||>>, |>>,
  3407 
  3408 * Pure/library.ML no longer defines its own option datatype, but uses
  3409 that of the SML basis, which has constructors NONE and SOME instead of
  3410 None and Some, as well as exception Option.Option instead of OPTION.
  3411 The functions the, if_none, is_some, is_none have been adapted
  3412 accordingly, while Option.map replaces apsome.
  3413 
  3414 * Pure/library.ML: the exception LIST has been given up in favour of
  3415 the standard exceptions Empty and Subscript, as well as
  3416 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3417 superceded by the standard hd and tl functions etc.
  3418 
  3419 A number of basic list functions are no longer exported to the ML
  3420 toplevel, as they are variants of predefined functions.  The following
  3421 suggests how one can translate existing code:
  3422 
  3423     rev_append xs ys = List.revAppend (xs, ys)
  3424     nth_elem (i, xs) = List.nth (xs, i)
  3425     last_elem xs = List.last xs
  3426     flat xss = List.concat xss
  3427     seq fs = List.app fs
  3428     partition P xs = List.partition P xs
  3429     mapfilter f xs = List.mapPartial f xs
  3430 
  3431 * Pure/library.ML: several combinators for linear functional
  3432 transformations, notably reverse application and composition:
  3433 
  3434   x |> f                f #> g
  3435   (x, y) |-> f          f #-> g
  3436 
  3437 * Pure/library.ML: introduced/changed precedence of infix operators:
  3438 
  3439   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3440   infix 2 ?;
  3441   infix 3 o oo ooo oooo;
  3442   infix 4 ~~ upto downto;
  3443 
  3444 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3445 infix operators.
  3446 
  3447 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3448 fold_map support linear functional transformations and nesting.  For
  3449 example:
  3450 
  3451   fold f [x1, ..., xN] y =
  3452     y |> f x1 |> ... |> f xN
  3453 
  3454   (fold o fold) f [xs1, ..., xsN] y =
  3455     y |> fold f xs1 |> ... |> fold f xsN
  3456 
  3457   fold f [x1, ..., xN] =
  3458     f x1 #> ... #> f xN
  3459 
  3460   (fold o fold) f [xs1, ..., xsN] =
  3461     fold f xs1 #> ... #> fold f xsN
  3462 
  3463 * Pure/library.ML: the following selectors on type 'a option are
  3464 available:
  3465 
  3466   the:               'a option -> 'a  (*partial*)
  3467   these:             'a option -> 'a  where 'a = 'b list
  3468   the_default: 'a -> 'a option -> 'a
  3469   the_list:          'a option -> 'a list
  3470 
  3471 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3472 basic operations for association lists, following natural argument
  3473 order; moreover the explicit equality predicate passed here avoids
  3474 potentially expensive polymorphic runtime equality checks.
  3475 The old functions may be expressed as follows:
  3476 
  3477   assoc = uncurry (AList.lookup (op =))
  3478   assocs = these oo AList.lookup (op =)
  3479   overwrite = uncurry (AList.update (op =)) o swap
  3480 
  3481 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3482 
  3483   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3484   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3485 
  3486 replacing make_keylist and keyfilter (occassionally used)
  3487 Naive rewrites:
  3488 
  3489   make_keylist = AList.make
  3490   keyfilter = AList.find (op =)
  3491 
  3492 * eq_fst and eq_snd now take explicit equality parameter, thus
  3493   avoiding eqtypes. Naive rewrites:
  3494 
  3495     eq_fst = eq_fst (op =)
  3496     eq_snd = eq_snd (op =)
  3497 
  3498 * Removed deprecated apl and apr (rarely used).
  3499   Naive rewrites:
  3500 
  3501     apl (n, op) =>>= curry op n
  3502     apr (op, m) =>>= fn n => op (n, m)
  3503 
  3504 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3505 provides a reasonably efficient light-weight implementation of sets as
  3506 lists.
  3507 
  3508 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3509 few new operations; existing lookup and update are now curried to
  3510 follow natural argument order (for use with fold etc.);
  3511 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3512 
  3513 * Pure/General: output via the Isabelle channels of
  3514 writeln/warning/error etc. is now passed through Output.output, with a
  3515 hook for arbitrary transformations depending on the print_mode
  3516 (cf. Output.add_mode -- the first active mode that provides a output
  3517 function wins).  Already formatted output may be embedded into further
  3518 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3519 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3520 accommodate easy composition of diagnostic messages etc.  Programmers
  3521 rarely need to care about Output.output or Output.raw at all, with
  3522 some notable exceptions: Output.output is required when bypassing the
  3523 standard channels (writeln etc.), or in token translations to produce
  3524 properly formatted results; Output.raw is required when capturing
  3525 already output material that will eventually be presented to the user
  3526 a second time.  For the default print mode, both Output.output and
  3527 Output.raw have no effect.
  3528 
  3529 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3530 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3531 cumulative results are displayed at the end of a batch session.
  3532 
  3533 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3534 replaced by File.platform_path and File.shell_path (with appropriate
  3535 hooks).  This provides a clean interface for unusual systems where the
  3536 internal and external process view of file names are different.
  3537 
  3538 * Pure: more efficient orders for basic syntactic entities: added
  3539 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3540 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3541 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3542 orders now -- potential INCOMPATIBILITY for code that depends on a
  3543 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3544 Library.sort_strings on result).
  3545 
  3546 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3547 fold_types traverse types/terms from left to right, observing natural
  3548 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3549 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3550 
  3551 * Pure: name spaces have been refined, with significant changes of the
  3552 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3553 to extern(_table).  The plain name entry path is superceded by a
  3554 general 'naming' context, which also includes the 'policy' to produce
  3555 a fully qualified name and external accesses of a fully qualified
  3556 name; NameSpace.extend is superceded by context dependent
  3557 Sign.declare_name.  Several theory and proof context operations modify
  3558 the naming context.  Especially note Theory.restore_naming and
  3559 ProofContext.restore_naming to get back to a sane state; note that
  3560 Theory.add_path is no longer sufficient to recover from
  3561 Theory.absolute_path in particular.
  3562 
  3563 * Pure: new flags short_names (default false) and unique_names
  3564 (default true) for controlling output of qualified names.  If
  3565 short_names is set, names are printed unqualified.  If unique_names is
  3566 reset, the name prefix is reduced to the minimum required to achieve
  3567 the original result when interning again, even if there is an overlap
  3568 with earlier declarations.
  3569 
  3570 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3571 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3572 (useful for printing error messages).  INCOMPATIBILITY.
  3573 
  3574 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3575 Theory.theory are now identified, referring to the universal
  3576 Context.theory (see Pure/context.ML).  Actual signature and theory
  3577 content is managed as theory data.  The old code and interfaces were
  3578 spread over many files and structures; the new arrangement introduces
  3579 considerable INCOMPATIBILITY to gain more clarity:
  3580 
  3581   Context -- theory management operations (name, identity, inclusion,
  3582     parents, ancestors, merge, etc.), plus generic theory data;
  3583 
  3584   Sign -- logical signature and syntax operations (declaring consts,
  3585     types, etc.), plus certify/read for common entities;
  3586 
  3587   Theory -- logical theory operations (stating axioms, definitions,
  3588     oracles), plus a copy of logical signature operations (consts,
  3589     types, etc.); also a few basic management operations (Theory.copy,
  3590     Theory.merge, etc.)
  3591 
  3592 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3593 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3594 for convenience -- they merely return the theory.
  3595 
  3596 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3597 
  3598 * Pure: the Isar proof context type is already defined early in Pure
  3599 as Context.proof (note that ProofContext.context and Proof.context are
  3600 aliases, where the latter is the preferred name).  This enables other
  3601 Isabelle components to refer to that type even before Isar is present.
  3602 
  3603 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3604 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3605 any of these kinds.  For example, Sign.intern typeK is now
  3606 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3607 Theory.hide_types.  Also note that former
  3608 Theory.hide_classes/types/consts are now
  3609 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3610 internalize their arguments!  INCOMPATIBILITY.
  3611 
  3612 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3613 datatype thmref (with constructors Name and NameSelection) instead of
  3614 plain string -- INCOMPATIBILITY;
  3615 
  3616 * Pure: cases produced by proof methods specify options, where NONE
  3617 means to remove case bindings -- INCOMPATIBILITY in
  3618 (RAW_)METHOD_CASES.
  3619 
  3620 * Pure: the following operations retrieve axioms or theorems from a
  3621 theory node or theory hierarchy, respectively:
  3622 
  3623   Theory.axioms_of: theory -> (string * term) list
  3624   Theory.all_axioms_of: theory -> (string * term) list
  3625   PureThy.thms_of: theory -> (string * thm) list
  3626   PureThy.all_thms_of: theory -> (string * thm) list
  3627 
  3628 * Pure: print_tac now outputs the goal through the trace channel.
  3629 
  3630 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3631 Reference Toplevel.debug (default false) controls detailed printing
  3632 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3633 controls execution profiling -- set to 1 for time and 2 for space
  3634 (both increase the runtime).
  3635 
  3636 * Isar session: The initial use of ROOT.ML is now always timed,
  3637 i.e. the log will show the actual process times, in contrast to the
  3638 elapsed wall-clock time that the outer shell wrapper produces.
  3639 
  3640 * Simplifier: improved handling of bound variables (nameless
  3641 representation, avoid allocating new strings).  Simprocs that invoke
  3642 the Simplifier recursively should use Simplifier.inherit_bounds to
  3643 avoid local name clashes.  Failure to do so produces warnings
  3644 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3645 for further details.
  3646 
  3647 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3648 bindings for all theorems stored within a given theory; this may help
  3649 in porting non-Isar theories to Isar ones, while keeping ML proof
  3650 scripts for the time being.
  3651 
  3652 * ML operator HTML.with_charset specifies the charset begin used for
  3653 generated HTML files.  For example:
  3654 
  3655   HTML.with_charset "utf-8" use_thy "Hebrew";
  3656   HTML.with_charset "utf-8" use_thy "Chinese";
  3657 
  3658 
  3659 *** System ***
  3660 
  3661 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3662 isabelle, isatool etc.).
  3663 
  3664 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3665 isatool doc, isatool mkdir, display_drafts etc.).
  3666 
  3667 * isatool usedir: option -f allows specification of the ML file to be
  3668 used by Isabelle; default is ROOT.ML.
  3669 
  3670 * New isatool version outputs the version identifier of the Isabelle
  3671 distribution being used.
  3672 
  3673 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3674 (containing Boolean satisfiability problems) into Isabelle/HOL
  3675 theories.
  3676 
  3677 
  3678 
  3679 New in Isabelle2004 (April 2004)
  3680 --------------------------------
  3681 
  3682 *** General ***
  3683 
  3684 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3685   Replaces linorder.ML.
  3686 
  3687 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3688   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3689   (\<a>...\<z>), are now considered normal letters, and can therefore
  3690   be used anywhere where an ASCII letter (a...zA...Z) has until
  3691   now. COMPATIBILITY: This obviously changes the parsing of some
  3692   terms, especially where a symbol has been used as a binder, say
  3693   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3694   as an identifier.  Fix it by inserting a space around former
  3695   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3696   existing theory and ML files.
  3697 
  3698 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3699 
  3700 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3701   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3702   a normal (but invisible) letter. For multiple letter subscripts repeat
  3703   \<^isub> like this: x\<^isub>1\<^isub>2.
  3704 
  3705 * Pure: There are now sub-/superscripts that can span more than one
  3706   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3707   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3708   superscript. The new control characters are not identifier parts.
  3709 
  3710 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3711   content of "..." to the latex file instead of \isacntrl... . The "..."
  3712   may consist of any printable characters excluding the end bracket >.
  3713 
  3714 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3715   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3716   declare constants "final", which prevents their being given a definition
  3717   later.  It is useful for constants whose behaviour is fixed axiomatically
  3718   rather than definitionally, such as the meta-logic connectives.
  3719 
  3720 * Pure: 'instance' now handles general arities with general sorts
  3721   (i.e. intersections of classes),
  3722 
  3723 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3724   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3725   It can be changed to alter the colors/layout of generated pages.
  3726 
  3727 
  3728 *** Isar ***
  3729 
  3730 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3731   cut_tac, subgoal_tac and thin_tac:
  3732   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3733     locales are no longer forced to write Isar proof scripts.
  3734     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3735     emulations.
  3736   - INCOMPATIBILITY: names of variables to be instantiated may no
  3737     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3738     This is consistent with the instantiation attribute "where".
  3739 
  3740 * Attributes "where" and "of":
  3741   - Now take type variables of instantiated theorem into account when reading
  3742     the instantiation string.  This fixes a bug that caused instantiated
  3743     theorems to have too special types in some circumstances.
  3744   - "where" permits explicit instantiations of type variables.
  3745 
  3746 * Calculation commands "moreover" and "also" no longer interfere with
  3747   current facts ("this"), admitting arbitrary combinations with "then"
  3748   and derived forms.
  3749 
  3750 * Locales:
  3751   - Goal statements involving the context element "includes" no longer
  3752     generate theorems with internal delta predicates (those ending on
  3753     "_axioms") in the premise.
  3754     Resolve particular premise with <locale>.intro to obtain old form.
  3755   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3756     specification and "includes" elements in goal statement.
  3757   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3758     [intro?] and [elim?] (respectively) by default.
  3759   - Experimental command for instantiation of locales in proof contexts:
  3760         instantiate <label>[<attrs>]: <loc>
  3761     Instantiates locale <loc> and adds all its theorems to the current context
  3762     taking into account their attributes.  Label and attrs are optional
  3763     modifiers, like in theorem declarations.  If present, names of
  3764     instantiated theorems are qualified with <label>, and the attributes
  3765     <attrs> are applied after any attributes these theorems might have already.
  3766       If the locale has assumptions, a chained fact of the form
  3767     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3768     are derived.  The command does not support old-style locales declared
  3769     with "locale (open)".
  3770       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3771 
  3772 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3773   (Isar) contexts.
  3774 
  3775 
  3776 *** HOL ***
  3777 
  3778 * Proof import: new image HOL4 contains the imported library from
  3779   the HOL4 system with about 2500 theorems. It is imported by
  3780   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3781   can be used like any other Isabelle image.  See
  3782   HOL/Import/HOL/README for more information.
  3783 
  3784 * Simplifier:
  3785   - Much improved handling of linear and partial orders.
  3786     Reasoners for linear and partial orders are set up for type classes
  3787     "linorder" and "order" respectively, and are added to the default simpset
  3788     as solvers.  This means that the simplifier can build transitivity chains
  3789     to solve goals from the assumptions.
  3790   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3791     of blast or auto after simplification become unnecessary because the goal
  3792     is solved by simplification already.
  3793 
  3794 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3795     all proved in axiomatic type classes for semirings, rings and fields.
  3796 
  3797 * Numerics:
  3798   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3799     now formalized using the Ring_and_Field theory mentioned above.
  3800   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3801     than before, because now they are set up once in a generic manner.
  3802   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3803     Look for the general versions in Ring_and_Field (and Power if they concern
  3804     exponentiation).
  3805 
  3806 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3807 
  3808 * Records:
  3809   - Record types are now by default printed with their type abbreviation
  3810     instead of the list of all field types. This can be configured via
  3811     the reference "print_record_type_abbr".
  3812   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3813     (not enabled by default).
  3814   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3815     EX x. x = sel r to True (not enabled by default).
  3816   - Tactic "record_split_simp_tac" to split and simplify records added.
  3817 
  3818 * 'specification' command added, allowing for definition by
  3819   specification.  There is also an 'ax_specification' command that
  3820   introduces the new constants axiomatically.
  3821 
  3822 * arith(_tac) is now able to generate counterexamples for reals as well.
  3823 
  3824 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3825 
  3826 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3827   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3828 
  3829 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3830   matrix theory to linear programming.
  3831 
  3832 * Unions and Intersections:
  3833   The latex output syntax of UN and INT has been changed
  3834   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3835   i.e. the index formulae has become a subscript.
  3836   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3837 
  3838 * Unions and Intersections over Intervals:
  3839   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3840   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3841   like in normal math, and corresponding versions for < and for intersection.
  3842 
  3843 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3844   lexicographic dictonary ordering has been added as "lexord".
  3845 
  3846 * ML: the legacy theory structures Int and List have been removed. They had
  3847   conflicted with ML Basis Library structures having the same names.
  3848 
  3849 * 'refute' command added to search for (finite) countermodels.  Only works
  3850   for a fragment of HOL.  The installation of an external SAT solver is
  3851   highly recommended.  See "HOL/Refute.thy" for details.
  3852 
  3853 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3854   formulae under an assignment of free variables to random values.
  3855   In contrast to 'refute', it can deal with inductive datatypes,
  3856   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3857   for examples.
  3858 
  3859 
  3860 *** HOLCF ***
  3861 
  3862 * Streams now come with concatenation and are part of the HOLCF image
  3863 
  3864 
  3865 
  3866 New in Isabelle2003 (May 2003)
  3867 ------------------------------
  3868 
  3869 *** General ***
  3870 
  3871 * Provers/simplifier:
  3872 
  3873   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3874     Assumptions are now subject to complete mutual simplification,
  3875     not just from left to right. The simplifier now preserves
  3876     the order of assumptions.
  3877 
  3878     Potential INCOMPATIBILITY:
  3879 
  3880     -- simp sometimes diverges where the old version did
  3881        not, e.g. invoking simp on the goal
  3882 
  3883         [| P (f x); y = x; f x = f y |] ==> Q
  3884 
  3885        now gives rise to the infinite reduction sequence
  3886 
  3887         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3888 
  3889        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3890        kind of problem.
  3891 
  3892     -- Tactics combining classical reasoner and simplification (such as auto)
  3893        are also affected by this change, because many of them rely on
  3894        simp. They may sometimes diverge as well or yield a different numbers
  3895        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3896        in case of problems. Sometimes subsequent calls to the classical
  3897        reasoner will fail because a preceeding call to the simplifier too
  3898        eagerly simplified the goal, e.g. deleted redundant premises.
  3899 
  3900   - The simplifier trace now shows the names of the applied rewrite rules
  3901 
  3902   - You can limit the number of recursive invocations of the simplifier
  3903     during conditional rewriting (where the simplifie tries to solve the
  3904     conditions before applying the rewrite rule):
  3905     ML "simp_depth_limit := n"
  3906     where n is an integer. Thus you can force termination where previously
  3907     the simplifier would diverge.
  3908 
  3909   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3910 
  3911   - No longer aborts on failed congruence proof.  Instead, the
  3912     congruence is ignored.
  3913 
  3914 * Pure: New generic framework for extracting programs from constructive
  3915   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3916   as HOL/Extraction for some case studies.
  3917 
  3918 * Pure: The main goal of the proof state is no longer shown by default, only
  3919 the subgoals. This behaviour is controlled by a new flag.
  3920    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  3921 (ML: Proof.show_main_goal).
  3922 
  3923 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  3924 rules whose conclusion matches subgoal 1:
  3925       PG menu: Isabelle/Isar -> Show me -> matching rules
  3926 The rules are ordered by how closely they match the subgoal.
  3927 In particular, rules that solve a subgoal outright are displayed first
  3928 (or rather last, the way they are printed).
  3929 (ML: ProofGeneral.print_intros())
  3930 
  3931 * Pure: New flag trace_unify_fail causes unification to print
  3932 diagnostic information (PG: in trace buffer) when it fails. This is
  3933 useful for figuring out why single step proofs like rule, erule or
  3934 assumption failed.
  3935 
  3936 * Pure: Locale specifications now produce predicate definitions
  3937 according to the body of text (covering assumptions modulo local
  3938 definitions); predicate "loc_axioms" covers newly introduced text,
  3939 while "loc" is cumulative wrt. all included locale expressions; the
  3940 latter view is presented only on export into the global theory
  3941 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  3942 on the old view without predicates;
  3943 
  3944 * Pure: predefined locales "var" and "struct" are useful for sharing
  3945 parameters (as in CASL, for example); just specify something like
  3946 ``var x + var y + struct M'' as import;
  3947 
  3948 * Pure: improved thms_containing: proper indexing of facts instead of
  3949 raw theorems; check validity of results wrt. current name space;
  3950 include local facts of proof configuration (also covers active
  3951 locales), cover fixed variables in index; may use "_" in term
  3952 specification; an optional limit for the number of printed facts may
  3953 be given (the default is 40);
  3954 
  3955 * Pure: disallow duplicate fact bindings within new-style theory files
  3956 (batch-mode only);
  3957 
  3958 * Provers: improved induct method: assumptions introduced by case
  3959 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  3960 the goal statement); "foo" still refers to all facts collectively;
  3961 
  3962 * Provers: the function blast.overloaded has been removed: all constants
  3963 are regarded as potentially overloaded, which improves robustness in exchange
  3964 for slight decrease in efficiency;
  3965 
  3966 * Provers/linorder: New generic prover for transitivity reasoning over
  3967 linear orders.  Note: this prover is not efficient!
  3968 
  3969 * Isar: preview of problems to finish 'show' now produce an error
  3970 rather than just a warning (in interactive mode);
  3971 
  3972 
  3973 *** HOL ***
  3974 
  3975 * arith(_tac)
  3976 
  3977  - Produces a counter example if it cannot prove a goal.
  3978    Note that the counter example may be spurious if the goal is not a formula
  3979    of quantifier-free linear arithmetic.
  3980    In ProofGeneral the counter example appears in the trace buffer.
  3981 
  3982  - Knows about div k and mod k where k is a numeral of type nat or int.
  3983 
  3984  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  3985    linear arithmetic fails. This takes account of quantifiers and divisibility.
  3986    Presburger arithmetic can also be called explicitly via presburger(_tac).
  3987 
  3988 * simp's arithmetic capabilities have been enhanced a bit: it now
  3989 takes ~= in premises into account (by performing a case split);
  3990 
  3991 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  3992 are distributed over a sum of terms;
  3993 
  3994 * New tactic "trans_tac" and method "trans" instantiate
  3995 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  3996 "<=", "<" and "=").
  3997 
  3998 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  3999 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4000 
  4001 * 'typedef' command has new option "open" to suppress the set
  4002 definition;
  4003 
  4004 * functions Min and Max on finite sets have been introduced (theory
  4005 Finite_Set);
  4006 
  4007 * attribute [symmetric] now works for relations as well; it turns
  4008 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4009 
  4010 * induct over a !!-quantified statement (say !!x1..xn):
  4011   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4012 
  4013 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4014 %x. None. Warning: empty_def now refers to the previously hidden definition
  4015 of the empty set.
  4016 
  4017 * Algebra: formalization of classical algebra.  Intended as base for
  4018 any algebraic development in Isabelle.  Currently covers group theory
  4019 (up to Sylow's theorem) and ring theory (Universal Property of
  4020 Univariate Polynomials).  Contributions welcome;
  4021 
  4022 * GroupTheory: deleted, since its material has been moved to Algebra;
  4023 
  4024 * Complex: new directory of the complex numbers with numeric constants,
  4025 nonstandard complex numbers, and some complex analysis, standard and
  4026 nonstandard (Jacques Fleuriot);
  4027 
  4028 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4029 
  4030 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4031 Fleuriot);
  4032 
  4033 * Real/HahnBanach: updated and adapted to locales;
  4034 
  4035 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4036 Gray and Kramer);
  4037 
  4038 * UNITY: added the Meier-Sanders theory of progress sets;
  4039 
  4040 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4041 as abstract algorithms, instantiated to the JVM;
  4042 
  4043 * Bali: Java source language formalization. Type system, operational
  4044 semantics, axiomatic semantics. Supported language features:
  4045 classes, interfaces, objects,virtual methods, static methods,
  4046 static/instance fields, arrays, access modifiers, definite
  4047 assignment, exceptions.
  4048 
  4049 
  4050 *** ZF ***
  4051 
  4052 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4053 universe, etc.);
  4054 
  4055 * Main ZF: virtually all theories converted to new-style format;
  4056 
  4057 
  4058 *** ML ***
  4059 
  4060 * Pure: Tactic.prove provides sane interface for internal proofs;
  4061 omits the infamous "standard" operation, so this is more appropriate
  4062 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4063 
  4064 * Pure: improved error reporting of simprocs;
  4065 
  4066 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4067 up simprocs;
  4068 
  4069 
  4070 *** Document preparation ***
  4071 
  4072 * uses \par instead of \\ for line breaks in theory text. This may
  4073 shift some page breaks in large documents. To get the old behaviour
  4074 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4075 
  4076 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4077 other packages
  4078 
  4079 * \<euro> now needs package babel/greek instead of marvosym (which
  4080 broke \Rightarrow)
  4081 
  4082 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4083 textcomp package)
  4084 
  4085 
  4086 
  4087 New in Isabelle2002 (March 2002)
  4088 --------------------------------
  4089 
  4090 *** Document preparation ***
  4091 
  4092 * greatly simplified document preparation setup, including more
  4093 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4094 instructive isatool mkdir; users should basically be able to get
  4095 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4096 users may run a separate document processing stage manually like this:
  4097 "isatool usedir -D output HOL Test && isatool document Test/output";
  4098 
  4099 * theory dependency graph may now be incorporated into documents;
  4100 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4101 with \includegraphics of LaTeX;
  4102 
  4103 * proper spacing of consecutive markup elements, especially text
  4104 blocks after section headings;
  4105 
  4106 * support bold style (for single symbols only), input syntax is like
  4107 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4108 
  4109 * \<bullet> is now output as bold \cdot by default, which looks much
  4110 better in printed text;
  4111 
  4112 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4113 note that these symbols are currently unavailable in Proof General /
  4114 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4115 
  4116 * isatool latex no longer depends on changed TEXINPUTS, instead
  4117 isatool document copies the Isabelle style files to the target
  4118 location;
  4119 
  4120 
  4121 *** Isar ***
  4122 
  4123 * Pure/Provers: improved proof by cases and induction;
  4124   - 'case' command admits impromptu naming of parameters (such as
  4125     "case (Suc n)");
  4126   - 'induct' method divinates rule instantiation from the inductive
  4127     claim; no longer requires excessive ?P bindings for proper
  4128     instantiation of cases;
  4129   - 'induct' method properly enumerates all possibilities of set/type
  4130     rules; as a consequence facts may be also passed through *type*
  4131     rules without further ado;
  4132   - 'induct' method now derives symbolic cases from the *rulified*
  4133     rule (before it used to rulify cases stemming from the internal
  4134     atomized version); this means that the context of a non-atomic
  4135     statement becomes is included in the hypothesis, avoiding the
  4136     slightly cumbersome show "PROP ?case" form;
  4137   - 'induct' may now use elim-style induction rules without chaining
  4138     facts, using ``missing'' premises from the goal state; this allows
  4139     rules stemming from inductive sets to be applied in unstructured
  4140     scripts, while still benefitting from proper handling of non-atomic
  4141     statements; NB: major inductive premises need to be put first, all
  4142     the rest of the goal is passed through the induction;
  4143   - 'induct' proper support for mutual induction involving non-atomic
  4144     rule statements (uses the new concept of simultaneous goals, see
  4145     below);
  4146   - append all possible rule selections, but only use the first
  4147     success (no backtracking);
  4148   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4149   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4150   - added 'print_induct_rules' (covered by help item in recent Proof
  4151     General versions);
  4152   - moved induct/cases attributes to Pure, methods to Provers;
  4153   - generic method setup instantiated for FOL and HOL;
  4154 
  4155 * Pure: support multiple simultaneous goal statements, for example
  4156 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4157 meta-level mechanism, this acts as if several individual goals had
  4158 been stated separately; in particular common proof methods need to be
  4159 repeated in order to cover all claims; note that a single elimination
  4160 step is *not* sufficient to establish the two conjunctions, so this
  4161 fails:
  4162 
  4163   assume "A & B" then have A and B ..   (*".." fails*)
  4164 
  4165 better use "obtain" in situations as above; alternative refer to
  4166 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4167 
  4168 * Pure: proper integration with ``locales''; unlike the original
  4169 version by Florian Kammller, Isar locales package high-level proof
  4170 contexts rather than raw logical ones (e.g. we admit to include
  4171 attributes everywhere); operations on locales include merge and
  4172 rename; support for implicit arguments (``structures''); simultaneous
  4173 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4174 some examples;
  4175 
  4176 * Pure: the following commands have been ``localized'', supporting a
  4177 target locale specification "(in name)": 'lemma', 'theorem',
  4178 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4179 stored both within the locale and at the theory level (exported and
  4180 qualified by the locale name);
  4181 
  4182 * Pure: theory goals may now be specified in ``long'' form, with
  4183 ad-hoc contexts consisting of arbitrary locale elements. for example
  4184 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4185 definitions may be given, too); the result is a meta-level rule with
  4186 the context elements being discharged in the obvious way;
  4187 
  4188 * Pure: new proof command 'using' allows to augment currently used
  4189 facts after a goal statement ('using' is syntactically analogous to
  4190 'apply', but acts on the goal's facts only); this allows chained facts
  4191 to be separated into parts given before and after a claim, as in
  4192 ``from a and b have C using d and e <proof>'';
  4193 
  4194 * Pure: renamed "antecedent" case to "rule_context";
  4195 
  4196 * Pure: new 'judgment' command records explicit information about the
  4197 object-logic embedding (used by several tools internally); no longer
  4198 use hard-wired "Trueprop";
  4199 
  4200 * Pure: added 'corollary' command;
  4201 
  4202 * Pure: fixed 'token_translation' command;
  4203 
  4204 * Pure: removed obsolete 'exported' attribute;
  4205 
  4206 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4207 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4208 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4209 
  4210 * Pure: method 'atomize' presents local goal premises as object-level
  4211 statements (atomic meta-level propositions); setup controlled via
  4212 rewrite rules declarations of 'atomize' attribute; example
  4213 application: 'induct' method with proper rule statements in improper
  4214 proof *scripts*;
  4215 
  4216 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4217 now consider the syntactic context of assumptions, giving a better
  4218 chance to get type-inference of the arguments right (this is
  4219 especially important for locales);
  4220 
  4221 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4222 mode;
  4223 
  4224 * Pure/obtain: the formal conclusion "thesis", being marked as
  4225 ``internal'', may no longer be reference directly in the text;
  4226 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4227 situations;
  4228 
  4229 * Pure: generic 'sym' attribute which declares a rule both as pure
  4230 'elim?' and for the 'symmetric' operation;
  4231 
  4232 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4233 text; the fixed correlation with particular command syntax has been
  4234 discontinued;
  4235 
  4236 * Pure: new method 'rules' is particularly well-suited for proof
  4237 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4238 but often produces more compact proof terms with less detours;
  4239 
  4240 * Pure/Provers/classical: simplified integration with pure rule
  4241 attributes and methods; the classical "intro?/elim?/dest?"
  4242 declarations coincide with the pure ones; the "rule" method no longer
  4243 includes classically swapped intros; "intro" and "elim" methods no
  4244 longer pick rules from the context; also got rid of ML declarations
  4245 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4246 INCOMPATIBILITY;
  4247 
  4248 * Provers/classical: attribute 'swapped' produces classical inversions
  4249 of introduction rules;
  4250 
  4251 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4252 rules instead of full simplifier context; 'iff' attribute handles
  4253 conditional rules;
  4254 
  4255 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4256 
  4257 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4258 "(permissive)" option to recover old behavior;
  4259 
  4260 * HOL: 'inductive' no longer features separate (collective) attributes
  4261 for 'intros' (was found too confusing);
  4262 
  4263 * HOL: properly declared induction rules less_induct and
  4264 wf_induct_rule;
  4265 
  4266 
  4267 *** HOL ***
  4268 
  4269 * HOL: moved over to sane numeral syntax; the new policy is as
  4270 follows:
  4271 
  4272   - 0 and 1 are polymorphic constants, which are defined on any
  4273   numeric type (nat, int, real etc.);
  4274 
  4275   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4276   binary representation internally;
  4277 
  4278   - type nat has special constructor Suc, and generally prefers Suc 0
  4279   over 1::nat and Suc (Suc 0) over 2::nat;
  4280 
  4281 This change may cause significant problems of INCOMPATIBILITY; here
  4282 are some hints on converting existing sources:
  4283 
  4284   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4285   entities, so expressions involving "-" (unary or binary minus) need
  4286   to be spaced properly;
  4287 
  4288   - existing occurrences of "1" may need to be constraint "1::nat" or
  4289   even replaced by Suc 0; similar for old "2";
  4290 
  4291   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4292 
  4293   - remove all special provisions on numerals in proofs;
  4294 
  4295 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4296 representation (depends on bin_arith_simps in the default context);
  4297 
  4298 * HOL: symbolic syntax for x^2 (numeral 2);
  4299 
  4300 * HOL: the class of all HOL types is now called "type" rather than
  4301 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4302 in axclass/classes, instance/arities, and (usually rare) occurrences
  4303 in typings (of consts etc.); internally the class is called
  4304 "HOL.type", ML programs should refer to HOLogic.typeS;
  4305 
  4306 * HOL/record package improvements:
  4307   - new derived operations "fields" to build a partial record section,
  4308     "extend" to promote a fixed record to a record scheme, and
  4309     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4310     declared as simp by default;
  4311   - shared operations ("more", "fields", etc.) now need to be always
  4312     qualified) --- potential INCOMPATIBILITY;
  4313   - removed "make_scheme" operations (use "make" with "extend") --
  4314     INCOMPATIBILITY;
  4315   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4316   - provides cases/induct rules for use with corresponding Isar
  4317     methods (for concrete records, record schemes, concrete more
  4318     parts, and schematic more parts -- in that order);
  4319   - internal definitions directly based on a light-weight abstract
  4320     theory of product types over typedef rather than datatype;
  4321 
  4322 * HOL: generic code generator for generating executable ML code from
  4323 specifications; specific support for HOL constructs such as inductive
  4324 datatypes and sets, as well as recursive functions; can be invoked
  4325 via 'generate_code' theory section;
  4326 
  4327 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4328 
  4329 * HOL: consolidated and renamed several theories.  In particular:
  4330         Ord.thy has been absorbed into HOL.thy
  4331         String.thy has been absorbed into List.thy
  4332 
  4333 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4334 (beware of argument permutation!);
  4335 
  4336 * HOL: linorder_less_split superseded by linorder_cases;
  4337 
  4338 * HOL/List: "nodups" renamed to "distinct";
  4339 
  4340 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4341 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4342   - Ex_def has changed, now need to use some_eq_ex
  4343 
  4344 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4345 in this (rare) case use:
  4346 
  4347   delSWrapper "split_all_tac"
  4348   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4349 
  4350 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4351 MAY FAIL;
  4352 
  4353 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4354 Isabelle's type classes, ^ on functions and relations has too general
  4355 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4356 necessary to attach explicit type constraints;
  4357 
  4358 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4359 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4360 renamed accordingly (eg "compI" -> "rel_compI").
  4361 
  4362 * HOL: syntax translations now work properly with numerals and records
  4363 expressions;
  4364 
  4365 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4366 of "lam" -- INCOMPATIBILITY;
  4367 
  4368 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4369 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4370 renamed "Product_Type.unit";
  4371 
  4372 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4373 
  4374 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4375 the "cases" method);
  4376 
  4377 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4378 Florian Kammller);
  4379 
  4380 * HOL/IMP: updated and converted to new-style theory format; several
  4381 parts turned into readable document, with proper Isar proof texts and
  4382 some explanations (by Gerwin Klein);
  4383 
  4384 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4385 
  4386 * HOL-Hyperreal is now a logic image;
  4387 
  4388 
  4389 *** HOLCF ***
  4390 
  4391 * Isar: consts/constdefs supports mixfix syntax for continuous
  4392 operations;
  4393 
  4394 * Isar: domain package adapted to new-style theory format, e.g. see
  4395 HOLCF/ex/Dnat.thy;
  4396 
  4397 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4398 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4399 lift.induct_tac, always use UU instead of Undef;
  4400 
  4401 * HOLCF/IMP: updated and converted to new-style theory;
  4402 
  4403 
  4404 *** ZF ***
  4405 
  4406 * Isar: proper integration of logic-specific tools and packages,
  4407 including theory commands '(co)inductive', '(co)datatype',
  4408 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4409 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4410 
  4411 * theory Main no longer includes AC; for the Axiom of Choice, base
  4412 your theory on Main_ZFC;
  4413 
  4414 * the integer library now covers quotients and remainders, with many
  4415 laws relating division to addition, multiplication, etc.;
  4416 
  4417 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4418 typeless version of the formalism;
  4419 
  4420 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4421 format;
  4422 
  4423 * ZF/Induct: new directory for examples of inductive definitions,
  4424 including theory Multiset for multiset orderings; converted to
  4425 new-style theory format;
  4426 
  4427 * ZF: many new theorems about lists, ordinals, etc.;
  4428 
  4429 
  4430 *** General ***
  4431 
  4432 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4433 variable proof controls level of detail: 0 = no proofs (only oracle
  4434 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4435 also ref manual for further ML interfaces;
  4436 
  4437 * Pure/axclass: removed obsolete ML interface
  4438 goal_subclass/goal_arity;
  4439 
  4440 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4441 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4442 separate tokens, so expressions involving minus need to be spaced
  4443 properly;
  4444 
  4445 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4446 rather than "infixl" or "infixr";
  4447 
  4448 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4449 sort constraint specifications in type inference; e.g. "x::_::foo"
  4450 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4451 type variable);
  4452 
  4453 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4454 control output of nested => (types); the default behavior is
  4455 "type_brackets";
  4456 
  4457 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4458 tokens into AST constants;
  4459 
  4460 * Pure/syntax: prefer later declarations of translations and print
  4461 translation functions; potential INCOMPATIBILITY: need to reverse
  4462 multiple declarations for same syntax element constant;
  4463 
  4464 * Pure/show_hyps reset by default (in accordance to existing Isar
  4465 practice);
  4466 
  4467 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4468 addSafter;
  4469 
  4470 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4471 as well;
  4472 
  4473 * system: tested support for MacOS X; should be able to get Isabelle +
  4474 Proof General to work in a plain Terminal after installing Poly/ML
  4475 (e.g. from the Isabelle distribution area) and GNU bash alone
  4476 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4477 support requires further installations, e.g. from
  4478 http://fink.sourceforge.net/);
  4479 
  4480 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4481 
  4482 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4483 of 40 MB), cf. ML_OPTIONS;
  4484 
  4485 * system: Proof General keywords specification is now part of the
  4486 Isabelle distribution (see etc/isar-keywords.el);
  4487 
  4488 * system: support for persistent Proof General sessions (refrain from
  4489 outdating all loaded theories on startup); user may create writable
  4490 logic images like this: ``isabelle -q HOL Test'';
  4491 
  4492 * system: smart selection of Isabelle process versus Isabelle
  4493 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4494 run both "isabelle" and "Isabelle" even if file names are badly
  4495 damaged (executable inspects the case of the first letter of its own
  4496 name); added separate "isabelle-process" and "isabelle-interface";
  4497 
  4498 * system: refrain from any attempt at filtering input streams; no
  4499 longer support ``8bit'' encoding of old isabelle font, instead proper
  4500 iso-latin characters may now be used; the related isatools
  4501 "symbolinput" and "nonascii" have disappeared as well;
  4502 
  4503 * system: removed old "xterm" interface (the print modes "xterm" and
  4504 "xterm_color" are still available for direct use in a suitable
  4505 terminal);
  4506 
  4507 
  4508 
  4509 New in Isabelle99-2 (February 2001)
  4510 -----------------------------------
  4511 
  4512 *** Overview of INCOMPATIBILITIES ***
  4513 
  4514 * HOL: please note that theories in the Library and elsewhere often use the
  4515 new-style (Isar) format; to refer to their theorems in an ML script you must
  4516 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4517 
  4518 * HOL: inductive package no longer splits induction rule aggressively,
  4519 but only as far as specified by the introductions given; the old
  4520 format may be recovered via ML function complete_split_rule or attribute
  4521 'split_rule (complete)';
  4522 
  4523 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4524 gfp_Tarski to gfp_unfold;
  4525 
  4526 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4527 
  4528 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4529 relation); infix "^^" has been renamed "``"; infix "``" has been
  4530 renamed "`"; "univalent" has been renamed "single_valued";
  4531 
  4532 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4533 operation;
  4534 
  4535 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4536 
  4537 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4538 
  4539 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4540 consequence, it is no longer monotonic wrt. the local goal context
  4541 (which is now passed through the inductive cases);
  4542 
  4543 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4544 \<gg> to \<ggreater>;
  4545 
  4546 
  4547 *** Document preparation ***
  4548 
  4549 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4550 available: are "it" for near math-mode best-style output, "sl" for
  4551 slanted text style, and "tt" for plain type-writer; if no
  4552 \isabellestyle command is given, output is according to slanted
  4553 type-writer);
  4554 
  4555 * support sub/super scripts (for single symbols only), input syntax is
  4556 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4557 
  4558 * some more standard symbols; see Appendix A of the system manual for
  4559 the complete list of symbols defined in isabellesym.sty;
  4560 
  4561 * improved isabelle style files; more abstract symbol implementation
  4562 (should now use \isamath{...} and \isatext{...} in custom symbol
  4563 definitions);
  4564 
  4565 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4566 state; Note that presentation of goal states does not conform to
  4567 actual human-readable proof documents.  Please do not include goal
  4568 states into document output unless you really know what you are doing!
  4569 
  4570 * proper indentation of antiquoted output with proportional LaTeX
  4571 fonts;
  4572 
  4573 * no_document ML operator temporarily disables LaTeX document
  4574 generation;
  4575 
  4576 * isatool unsymbolize tunes sources for plain ASCII communication;
  4577 
  4578 
  4579 *** Isar ***
  4580 
  4581 * Pure: Isar now suffers initial goal statements to contain unbound
  4582 schematic variables (this does not conform to actual readable proof
  4583 documents, due to unpredictable outcome and non-compositional proof
  4584 checking); users who know what they are doing may use schematic goals
  4585 for Prolog-style synthesis of proven results;
  4586 
  4587 * Pure: assumption method (an implicit finishing) now handles actual
  4588 rules as well;
  4589 
  4590 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4591 initial goal, declare "that" only as Pure intro (only for single
  4592 steps); the "that" rule assumption may now be involved in implicit
  4593 finishing, thus ".." becomes a feasible for trivial obtains;
  4594 
  4595 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4596 instance proofs may be performed by "..";
  4597 
  4598 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4599 statements as well;
  4600 
  4601 * Pure: more robust selection of calculational rules;
  4602 
  4603 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4604 rule (as well as the assumption rule);
  4605 
  4606 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4607 lemmas, using the graph browser tool;
  4608 
  4609 * Pure: predict failure of "show" in interactive mode;
  4610 
  4611 * Pure: 'thms_containing' now takes actual terms as arguments;
  4612 
  4613 * HOL: improved method 'induct' --- now handles non-atomic goals
  4614 (potential INCOMPATIBILITY); tuned error handling;
  4615 
  4616 * HOL: cases and induct rules now provide explicit hints about the
  4617 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4618 any remaining facts are inserted into the goal verbatim;
  4619 
  4620 * HOL: local contexts (aka cases) may now contain term bindings as
  4621 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4622 the result to be shown in each case;
  4623 
  4624 * HOL: added 'recdef_tc' command;
  4625 
  4626 * isatool convert assists in eliminating legacy ML scripts;
  4627 
  4628 
  4629 *** HOL ***
  4630 
  4631 * HOL/Library: a collection of generic theories to be used together
  4632 with main HOL; the theory loader path already includes this directory
  4633 by default; the following existing theories have been moved here:
  4634 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4635 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4636 
  4637 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4638 modelling and verification task performed in Isabelle/HOL +
  4639 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4640 
  4641 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4642 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4643 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4644 'domain', this makes the theory consistent with mathematical
  4645 literature;
  4646 
  4647 * HOL basics: added overloaded operations "inverse" and "divide"
  4648 (infix "/"), syntax for generic "abs" operation, generic summation
  4649 operator \<Sum>;
  4650 
  4651 * HOL/typedef: simplified package, provide more useful rules (see also
  4652 HOL/subset.thy);
  4653 
  4654 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4655 now expressed as a proper nested rule (old-style tactic scripts may
  4656 require atomize_strip_tac to cope with non-atomic premises);
  4657 
  4658 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4659 to "split_conv" (old name still available for compatibility);
  4660 
  4661 * HOL: improved concrete syntax for strings (e.g. allows translation
  4662 rules with string literals);
  4663 
  4664 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4665  and Fleuriot's mechanization of analysis, including the transcendental
  4666  functions for the reals;
  4667 
  4668 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4669 
  4670 
  4671 *** CTT ***
  4672 
  4673 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4674 "lam" is displayed as TWO lambda-symbols
  4675 
  4676 * CTT: theory Main now available, containing everything (that is, Bool
  4677 and Arith);
  4678 
  4679 
  4680 *** General ***
  4681 
  4682 * Pure: the Simplifier has been implemented properly as a derived rule
  4683 outside of the actual kernel (at last!); the overall performance
  4684 penalty in practical applications is about 50%, while reliability of
  4685 the Isabelle inference kernel has been greatly improved;
  4686 
  4687 * print modes "brackets" and "no_brackets" control output of nested =>
  4688 (types) and ==> (props); the default behaviour is "brackets";
  4689 
  4690 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4691 as assumptions as well;
  4692 
  4693 * system: support Poly/ML 4.0;
  4694 
  4695 * system: isatool install handles KDE version 1 or 2;
  4696 
  4697 
  4698 
  4699 New in Isabelle99-1 (October 2000)
  4700 ----------------------------------
  4701 
  4702 *** Overview of INCOMPATIBILITIES ***
  4703 
  4704 * HOL: simplification of natural numbers is much changed; to partly
  4705 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4706 issue the following ML commands:
  4707 
  4708   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4709   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4710 
  4711 * HOL: simplification no longer dives into case-expressions; this is
  4712 controlled by "t.weak_case_cong" for each datatype t;
  4713 
  4714 * HOL: nat_less_induct renamed to less_induct;
  4715 
  4716 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4717 fixsome to patch .thy and .ML sources automatically;
  4718 
  4719   select_equality  -> some_equality
  4720   select_eq_Ex     -> some_eq_ex
  4721   selectI2EX       -> someI2_ex
  4722   selectI2         -> someI2
  4723   selectI          -> someI
  4724   select1_equality -> some1_equality
  4725   Eps_sym_eq       -> some_sym_eq_trivial
  4726   Eps_eq           -> some_eq_trivial
  4727 
  4728 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4729 
  4730 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4731 instead);
  4732 
  4733 * HOL: the recursion equations generated by 'recdef' are now called
  4734 f.simps instead of f.rules;
  4735 
  4736 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4737 
  4738 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4739 sometimes be needed;
  4740 
  4741 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4742 
  4743 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4744 
  4745 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4746 product is now "<*>" instead of "Times"; the lexicographic product is
  4747 now "<*lex*>" instead of "**";
  4748 
  4749 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4750 of main HOL, but was unused); better use HOL's datatype package;
  4751 
  4752 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4753 the old syntax may be recovered as follows:
  4754 
  4755   syntax (symbols)
  4756     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4757       (infixl "\\<oplus>" 100)
  4758 
  4759 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4760 
  4761 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4762 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4763 internally;
  4764 
  4765 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4766 changed from A/r to A//r;
  4767 
  4768 * ZF: new treatment of arithmetic (nat & int) may break some old
  4769 proofs;
  4770 
  4771 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4772 rulify -> rule_format, elimify -> elim_format, ...);
  4773 
  4774 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4775 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4776 should have to change intro!! to intro? only); replaced "delrule" by
  4777 "rule del";
  4778 
  4779 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4780 
  4781 * Provers: strengthened force_tac by using new first_best_tac;
  4782 
  4783 * LaTeX document preparation: several changes of isabelle.sty (see
  4784 lib/texinputs);
  4785 
  4786 
  4787 *** Document preparation ***
  4788 
  4789 * formal comments (text blocks etc.) in new-style theories may now
  4790 contain antiquotations of thm/prop/term/typ/text to be presented
  4791 according to latex print mode; concrete syntax is like this:
  4792 @{term[show_types] "f(x) = a + x"};
  4793 
  4794 * isatool mkdir provides easy setup of Isabelle session directories,
  4795 including proper document sources;
  4796 
  4797 * generated LaTeX sources are now deleted after successful run
  4798 (isatool document -c); may retain a copy somewhere else via -D option
  4799 of isatool usedir;
  4800 
  4801 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4802 style files, achieving self-contained LaTeX sources and simplifying
  4803 LaTeX debugging;
  4804 
  4805 * old-style theories now produce (crude) LaTeX output as well;
  4806 
  4807 * browser info session directories are now self-contained (may be put
  4808 on WWW server seperately); improved graphs of nested sessions; removed
  4809 graph for 'all sessions';
  4810 
  4811 * several improvements in isabelle style files; \isabellestyle{it}
  4812 produces fake math mode output; \isamarkupheader is now \section by
  4813 default; see lib/texinputs/isabelle.sty etc.;
  4814 
  4815 
  4816 *** Isar ***
  4817 
  4818 * Isar/Pure: local results and corresponding term bindings are now
  4819 subject to Hindley-Milner polymorphism (similar to ML); this
  4820 accommodates incremental type-inference very nicely;
  4821 
  4822 * Isar/Pure: new derived language element 'obtain' supports
  4823 generalized existence reasoning;
  4824 
  4825 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4826 support accumulation of results, without applying any rules yet;
  4827 useful to collect intermediate results without explicit name
  4828 references, and for use with transitivity rules with more than 2
  4829 premises;
  4830 
  4831 * Isar/Pure: scalable support for case-analysis type proofs: new
  4832 'case' language element refers to local contexts symbolically, as
  4833 produced by certain proof methods; internally, case names are attached
  4834 to theorems as "tags";
  4835 
  4836 * Isar/Pure: theory command 'hide' removes declarations from
  4837 class/type/const name spaces;
  4838 
  4839 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4840 indicate potential overloading;
  4841 
  4842 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4843 
  4844 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4845 "{a,b,c}" instead of {a,b,c};
  4846 
  4847 * Isar/Pure now provides its own version of intro/elim/dest
  4848 attributes; useful for building new logics, but beware of confusion
  4849 with the version in Provers/classical;
  4850 
  4851 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4852 case name 'antecedent';
  4853 
  4854 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4855 to the current context is now done automatically);
  4856 
  4857 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4858 for definining proof methods in ML;
  4859 
  4860 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4861 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4862 most cases, one should have to change intro!! to intro? only);
  4863 replaced "delrule" by "rule del";
  4864 
  4865 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4866 'symmetric' attribute (the latter supercedes [RS sym]);
  4867 
  4868 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4869 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4870 well (including splits);
  4871 
  4872 * Isar/Provers: Simplifier and Classical methods now support all kind
  4873 of modifiers used in the past, including 'cong', 'iff', etc.
  4874 
  4875 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4876 of Simplifier and Classical reasoner);
  4877 
  4878 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4879 now support named cases; major packages (inductive, datatype, primrec,
  4880 recdef) support case names and properly name parameters;
  4881 
  4882 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4883 monotonicity conditions are extracted to be proven at end of
  4884 calculations;
  4885 
  4886 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4887 method anyway;
  4888 
  4889 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4890 split_if split_if_asm; datatype package provides theorems foo.splits =
  4891 foo.split foo.split_asm for each datatype;
  4892 
  4893 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4894 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4895 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4896 use "(cases (simplified))" method in proper proof texts);
  4897 
  4898 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4899 
  4900 * Isar: names of theorems etc. may be natural numbers as well;
  4901 
  4902 * Isar: 'pr' command: optional arguments for goals_limit and
  4903 ProofContext.prems_limit; no longer prints theory contexts, but only
  4904 proof states;
  4905 
  4906 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4907 additional print modes to be specified; e.g. "pr(latex)" will print
  4908 proof state according to the Isabelle LaTeX style;
  4909 
  4910 * Isar: improved support for emulating tactic scripts, including proof
  4911 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4912 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4913 (for HOL datatypes);
  4914 
  4915 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4916 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4917 'proof method scripts' have to be in depth-first order;
  4918 
  4919 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  4920 
  4921 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  4922 should instead use individual commands for printing items
  4923 (print_commands, print_methods etc.);
  4924 
  4925 * Isar: added 'nothing' --- the empty list of theorems;
  4926 
  4927 
  4928 *** HOL ***
  4929 
  4930 * HOL/MicroJava: formalization of a fragment of Java, together with a
  4931 corresponding virtual machine and a specification of its bytecode
  4932 verifier and a lightweight bytecode verifier, including proofs of
  4933 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  4934 Cornelia Pusch (see also the homepage of project Bali at
  4935 http://isabelle.in.tum.de/Bali/);
  4936 
  4937 * HOL/Algebra: new theory of rings and univariate polynomials, by
  4938 Clemens Ballarin;
  4939 
  4940 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  4941 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  4942 Rasmussen;
  4943 
  4944 * HOL/Lattice: fundamental concepts of lattice theory and order
  4945 structures, including duals, properties of bounds versus algebraic
  4946 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  4947 Theorem for complete lattices etc.; may also serve as a demonstration
  4948 for abstract algebraic reasoning using axiomatic type classes, and
  4949 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  4950 
  4951 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  4952 von Oheimb;
  4953 
  4954 * HOL/IMPP: extension of IMP with local variables and mutually
  4955 recursive procedures, by David von Oheimb;
  4956 
  4957 * HOL/Lambda: converted into new-style theory and document;
  4958 
  4959 * HOL/ex/Multiquote: example of multiple nested quotations and
  4960 anti-quotations -- basically a generalized version of de-Bruijn
  4961 representation; very useful in avoiding lifting of operations;
  4962 
  4963 * HOL/record: added general record equality rule to simpset; fixed
  4964 select-update simplification procedure to handle extended records as
  4965 well; admit "r" as field name;
  4966 
  4967 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  4968 other numeric types and also as the identity of groups, rings, etc.;
  4969 
  4970 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  4971 Types nat and int belong to this axclass;
  4972 
  4973 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  4974    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  4975    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  4976   two terms #m*u and #n*u are replaced by #(m+n)*u
  4977     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  4978   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  4979     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  4980 
  4981 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  4982 powerful prover for predicate logic but knows nothing of clasets; see
  4983 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  4984 
  4985 * HOL: new version of "case_tac" subsumes both boolean case split and
  4986 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  4987 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  4988 
  4989 * HOL: simplification no longer dives into case-expressions: only the
  4990 selector expression is simplified, but not the remaining arms; to
  4991 enable full simplification of case-expressions for datatype t, you may
  4992 remove t.weak_case_cong from the simpset, either globally (Delcongs
  4993 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  4994 
  4995 * HOL/recdef: the recursion equations generated by 'recdef' for
  4996 function 'f' are now called f.simps instead of f.rules; if all
  4997 termination conditions are proved automatically, these simplification
  4998 rules are added to the simpset, as in primrec; rules may be named
  4999 individually as well, resulting in a separate list of theorems for
  5000 each equation;
  5001 
  5002 * HOL/While is a new theory that provides a while-combinator. It
  5003 permits the definition of tail-recursive functions without the
  5004 provision of a termination measure. The latter is necessary once the
  5005 invariant proof rule for while is applied.
  5006 
  5007 * HOL: new (overloaded) notation for the set of elements below/above
  5008 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5009 
  5010 * HOL: theorems impI, allI, ballI bound as "strip";
  5011 
  5012 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5013 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5014 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5015 
  5016 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5017 
  5018 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5019 main HOL, but was unused);
  5020 
  5021 * HOL: fewer consts declared as global (e.g. have to refer to
  5022 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5023 
  5024 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5025 in case of overlap with user translations (e.g. judgements over
  5026 tuples); (note that the underlying logical represenation is still
  5027 bogus);
  5028 
  5029 
  5030 *** ZF ***
  5031 
  5032 * ZF: simplification automatically cancels common terms in arithmetic
  5033 expressions over nat and int;
  5034 
  5035 * ZF: new treatment of nat to minimize type-checking: all operators
  5036 coerce their operands to a natural number using the function natify,
  5037 making the algebraic laws unconditional;
  5038 
  5039 * ZF: as above, for int: operators coerce their operands to an integer
  5040 using the function intify;
  5041 
  5042 * ZF: the integer library now contains many of the usual laws for the
  5043 orderings, including $<=, and monotonicity laws for $+ and $*;
  5044 
  5045 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5046 simplification;
  5047 
  5048 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5049 to the simplifier and classical reasoner simultaneously;
  5050 
  5051 
  5052 *** General ***
  5053 
  5054 * Provers: blast_tac now handles actual object-logic rules as
  5055 assumptions; note that auto_tac uses blast_tac internally as well;
  5056 
  5057 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5058 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5059 
  5060 * Provers: delrules now handles destruct rules as well (no longer need
  5061 explicit make_elim);
  5062 
  5063 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5064   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5065 use instead the strong form,
  5066   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5067 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5068 from destruct-rules;
  5069 
  5070 * Provers: Simplifier.easy_setup provides a fast path to basic
  5071 Simplifier setup for new object-logics;
  5072 
  5073 * Pure: AST translation rules no longer require constant head on LHS;
  5074 
  5075 * Pure: improved name spaces: ambiguous output is qualified; support
  5076 for hiding of names;
  5077 
  5078 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5079 XSYMBOL_HOME; no longer need to do manual configuration in most
  5080 situations;
  5081 
  5082 * system: compression of ML heaps images may now be controlled via -c
  5083 option of isabelle and isatool usedir (currently only observed by
  5084 Poly/ML);
  5085 
  5086 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5087 useful for remote X11);
  5088 
  5089 * system: provide TAGS file for Isabelle sources;
  5090 
  5091 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5092 order;
  5093 
  5094 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5095 timing flag supersedes proof_timing and Toplevel.trace;
  5096 
  5097 * ML: new combinators |>> and |>>> for incremental transformations
  5098 with secondary results (e.g. certain theory extensions):
  5099 
  5100 * ML: PureThy.add_defs gets additional argument to indicate potential
  5101 overloading (usually false);
  5102 
  5103 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5104 results;
  5105 
  5106 
  5107 
  5108 New in Isabelle99 (October 1999)
  5109 --------------------------------
  5110 
  5111 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5112 
  5113 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5114 are no longer simplified.  (This allows the simplifier to unfold recursive
  5115 functional programs.)  To restore the old behaviour, declare
  5116 
  5117     Delcongs [if_weak_cong];
  5118 
  5119 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5120 complement;
  5121 
  5122 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5123 
  5124 * HOL/datatype: mutual_induct_tac no longer exists --
  5125   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5126 
  5127 * HOL/typedef: fixed type inference for representing set; type
  5128 arguments now have to occur explicitly on the rhs as type constraints;
  5129 
  5130 * ZF: The con_defs part of an inductive definition may no longer refer
  5131 to constants declared in the same theory;
  5132 
  5133 * HOL, ZF: the function mk_cases, generated by the inductive
  5134 definition package, has lost an argument.  To simplify its result, it
  5135 uses the default simpset instead of a supplied list of theorems.
  5136 
  5137 * HOL/List: the constructors of type list are now Nil and Cons;
  5138 
  5139 * Simplifier: the type of the infix ML functions
  5140         setSSolver addSSolver setSolver addSolver
  5141 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5142 for packaging solvers. A solver is created via
  5143         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5144 where the string argument is only a comment.
  5145 
  5146 
  5147 *** Proof tools ***
  5148 
  5149 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5150 decision procedure for linear arithmetic. Currently it is used for
  5151 types `nat', `int', and `real' in HOL (see below); it can, should and
  5152 will be instantiated for other types and logics as well.
  5153 
  5154 * The simplifier now accepts rewrite rules with flexible heads, eg
  5155      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5156   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5157   matching.
  5158 
  5159 
  5160 *** General ***
  5161 
  5162 * New Isabelle/Isar subsystem provides an alternative to traditional
  5163 tactical theorem proving; together with the ProofGeneral/isar user
  5164 interface it offers an interactive environment for developing human
  5165 readable proof documents (Isar == Intelligible semi-automated
  5166 reasoning); for further information see isatool doc isar-ref,
  5167 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5168 
  5169 * improved and simplified presentation of theories: better HTML markup
  5170 (including colors), graph views in several sizes; isatool usedir now
  5171 provides a proper interface for user theories (via -P option); actual
  5172 document preparation based on (PDF)LaTeX is available as well (for
  5173 new-style theories only); see isatool doc system for more information;
  5174 
  5175 * native support for Proof General, both for classic Isabelle and
  5176 Isabelle/Isar;
  5177 
  5178 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5179 using the graph browser tool;
  5180 
  5181 * Isabelle manuals now also available as PDF;
  5182 
  5183 * theory loader rewritten from scratch (may not be fully
  5184 bug-compatible); old loadpath variable has been replaced by show_path,
  5185 add_path, del_path, reset_path functions; new operations such as
  5186 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5187 isatool doc ref);
  5188 
  5189 * improved isatool install: option -k creates KDE application icon,
  5190 option -p DIR installs standalone binaries;
  5191 
  5192 * added ML_PLATFORM setting (useful for cross-platform installations);
  5193 more robust handling of platform specific ML images for SML/NJ;
  5194 
  5195 * the settings environment is now statically scoped, i.e. it is never
  5196 created again in sub-processes invoked from isabelle, isatool, or
  5197 Isabelle;
  5198 
  5199 * path element specification '~~' refers to '$ISABELLE_HOME';
  5200 
  5201 * in locales, the "assumes" and "defines" parts may be omitted if
  5202 empty;
  5203 
  5204 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5205 long arrows);
  5206 
  5207 * new print_mode "HTML";
  5208 
  5209 * new flag show_tags controls display of tags of theorems (which are
  5210 basically just comments that may be attached by some tools);
  5211 
  5212 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5213 mode and goal output format:
  5214 
  5215 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5216 244c244
  5217 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5218 ---
  5219 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5220 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5221 181c181
  5222 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5223 ---
  5224 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5225 
  5226 * function bind_thms stores lists of theorems (cf. bind_thm);
  5227 
  5228 * new shorthand tactics ftac, eatac, datac, fatac;
  5229 
  5230 * qed (and friends) now accept "" as result name; in that case the
  5231 theorem is not stored, but proper checks and presentation of the
  5232 result still apply;
  5233 
  5234 * theorem database now also indexes constants "Trueprop", "all",
  5235 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5236 
  5237 
  5238 *** HOL ***
  5239 
  5240 ** HOL arithmetic **
  5241 
  5242 * There are now decision procedures for linear arithmetic over nat and
  5243 int:
  5244 
  5245 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5246 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5247 are treated as atomic; subformulae not involving type `nat' or `int'
  5248 are ignored; quantified subformulae are ignored unless they are
  5249 positive universal or negative existential. The tactic has to be
  5250 invoked by hand and can be a little bit slow. In particular, the
  5251 running time is exponential in the number of occurrences of `min' and
  5252 `max', and `-' on `nat'.
  5253 
  5254 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5255 (negated) (in)equalities among the premises and the conclusion into
  5256 account (i.e. no compound formulae) and does not know about `min' and
  5257 `max', and `-' on `nat'. It is fast and is used automatically by the
  5258 simplifier.
  5259 
  5260 NB: At the moment, these decision procedures do not cope with mixed
  5261 nat/int formulae where the two parts interact, such as `m < n ==>
  5262 int(m) < int(n)'.
  5263 
  5264 * HOL/Numeral provides a generic theory of numerals (encoded
  5265 efficiently as bit strings); setup for types nat/int/real is in place;
  5266 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5267 int, existing theories and proof scripts may require a few additional
  5268 type constraints;
  5269 
  5270 * integer division and remainder can now be performed on constant
  5271 arguments;
  5272 
  5273 * many properties of integer multiplication, division and remainder
  5274 are now available;
  5275 
  5276 * An interface to the Stanford Validity Checker (SVC) is available through the
  5277 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5278 are proved automatically.  SVC must be installed separately, and its results
  5279 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5280 invocation of the underlying oracle).  For SVC see
  5281   http://verify.stanford.edu/SVC
  5282 
  5283 * IsaMakefile: the HOL-Real target now builds an actual image;
  5284 
  5285 
  5286 ** HOL misc **
  5287 
  5288 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5289 (in Isabelle/Isar) -- by Gertrud Bauer;
  5290 
  5291 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5292 analysis for assembly languages with subtypes;
  5293 
  5294 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5295 -- avoids syntactic ambiguities and treats state, transition, and
  5296 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5297 changed syntax and (many) tactics;
  5298 
  5299 * HOL/inductive: Now also handles more general introduction rules such
  5300   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5301   theorems are now maintained within the theory (maintained via the
  5302   "mono" attribute);
  5303 
  5304 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5305   (using function types) such as
  5306 
  5307   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5308 
  5309 * HOL/record: record_simproc (part of the default simpset) takes care
  5310 of selectors applied to updated records; record_split_tac is no longer
  5311 part of the default claset; update_defs may now be removed from the
  5312 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5313 
  5314   claset_ref () := claset() addSWrapper record_split_wrapper;
  5315   Delsimprocs [record_simproc]
  5316 
  5317 * HOL/typedef: fixed type inference for representing set; type
  5318 arguments now have to occur explicitly on the rhs as type constraints;
  5319 
  5320 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5321 names rather than an ML expression;
  5322 
  5323 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5324 supplied later.  Program schemes can be defined, such as
  5325     "While B C s = (if B s then While B C (C s) else s)"
  5326 where the well-founded relation can be chosen after B and C have been given.
  5327 
  5328 * HOL/List: the constructors of type list are now Nil and Cons;
  5329 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5330 course, ML tools referring to List.list.op # etc. have to be adapted;
  5331 
  5332 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5333 disabled by default; run isabelle with option -m HOL to get back to
  5334 the original Gordon/HOL-style output;
  5335 
  5336 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5337 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5338 
  5339 * HOL basic syntax simplified (more orthogonal): all variants of
  5340 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5341 Eps operator is provided as well: "SOME x. P[x]";
  5342 
  5343 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5344 
  5345 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5346 thus available for user theories;
  5347 
  5348 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5349 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5350 time;
  5351 
  5352 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5353 several times and then mp;
  5354 
  5355 
  5356 *** LK ***
  5357 
  5358 * the notation <<...>> is now available as a notation for sequences of
  5359 formulas;
  5360 
  5361 * the simplifier is now installed
  5362 
  5363 * the axiom system has been generalized (thanks to Soren Heilmann)
  5364 
  5365 * the classical reasoner now has a default rule database
  5366 
  5367 
  5368 *** ZF ***
  5369 
  5370 * new primrec section allows primitive recursive functions to be given
  5371 directly (as in HOL) over datatypes and the natural numbers;
  5372 
  5373 * new tactics induct_tac and exhaust_tac for induction (or case
  5374 analysis) over datatypes and the natural numbers;
  5375 
  5376 * the datatype declaration of type T now defines the recursor T_rec;
  5377 
  5378 * simplification automatically does freeness reasoning for datatype
  5379 constructors;
  5380 
  5381 * automatic type-inference, with AddTCs command to insert new
  5382 type-checking rules;
  5383 
  5384 * datatype introduction rules are now added as Safe Introduction rules
  5385 to the claset;
  5386 
  5387 * the syntax "if P then x else y" is now available in addition to
  5388 if(P,x,y);
  5389 
  5390 
  5391 *** Internal programming interfaces ***
  5392 
  5393 * tuned simplifier trace output; new flag debug_simp;
  5394 
  5395 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5396 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5397 
  5398 * AxClass.axclass_tac lost the theory argument;
  5399 
  5400 * tuned current_goals_markers semantics: begin / end goal avoids
  5401 printing empty lines;
  5402 
  5403 * removed prs and prs_fn hook, which was broken because it did not
  5404 include \n in its semantics, forcing writeln to add one
  5405 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5406 string -> unit if you really want to output text without newline;
  5407 
  5408 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5409 plain output, interface builders may have to enable 'isabelle_font'
  5410 mode to get Isabelle font glyphs as before;
  5411 
  5412 * refined token_translation interface; INCOMPATIBILITY: output length
  5413 now of type real instead of int;
  5414 
  5415 * theory loader actions may be traced via new ThyInfo.add_hook
  5416 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5417 your own database of information attached to *whole* theories -- as
  5418 opposed to intra-theory data slots offered via TheoryDataFun;
  5419 
  5420 * proper handling of dangling sort hypotheses (at last!);
  5421 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5422 extra sort hypotheses that can be witnessed from the type signature;
  5423 the force_strip_shyps flag is gone, any remaining shyps are simply
  5424 left in the theorem (with a warning issued by strip_shyps_warning);
  5425 
  5426 
  5427 
  5428 New in Isabelle98-1 (October 1998)
  5429 ----------------------------------
  5430 
  5431 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5432 
  5433 * several changes of automated proof tools;
  5434 
  5435 * HOL: major changes to the inductive and datatype packages, including
  5436 some minor incompatibilities of theory syntax;
  5437 
  5438 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5439 called `inj_on';
  5440 
  5441 * HOL: removed duplicate thms in Arith:
  5442   less_imp_add_less  should be replaced by  trans_less_add1
  5443   le_imp_add_le      should be replaced by  trans_le_add1
  5444 
  5445 * HOL: unary minus is now overloaded (new type constraints may be
  5446 required);
  5447 
  5448 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5449 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5450 now taken as an integer constant.
  5451 
  5452 * Pure: ML function 'theory_of' renamed to 'theory';
  5453 
  5454 
  5455 *** Proof tools ***
  5456 
  5457 * Simplifier:
  5458   1. Asm_full_simp_tac is now more aggressive.
  5459      1. It will sometimes reorient premises if that increases their power to
  5460         simplify.
  5461      2. It does no longer proceed strictly from left to right but may also
  5462         rotate premises to achieve further simplification.
  5463      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5464      old Asm_full_simp_tac in that it does not rotate premises.
  5465   2. The simplifier now knows a little bit about nat-arithmetic.
  5466 
  5467 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5468 allows for selected deletion of wrappers, by introduction of names for
  5469 wrapper functionals.  This implies that addbefore, addSbefore,
  5470 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5471 and that adding two tactics with the same name overwrites the first
  5472 one (emitting a warning).
  5473   type wrapper = (int -> tactic) -> (int -> tactic)
  5474   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5475   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5476   delWrapper, delSWrapper: claset *  string            -> claset
  5477   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5478 
  5479 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5480 semantics; addbefore now affects only the unsafe part of step_tac
  5481 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5482 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5483 by Force_tac;
  5484 
  5485 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5486 compWrapper; added safe wrapper (and access functions for it);
  5487 
  5488 * HOL/split_all_tac is now much faster and fails if there is nothing
  5489 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5490 and the names of the automatically generated variables have changed.
  5491 split_all_tac has moved within claset() from unsafe wrappers to safe
  5492 wrappers, which means that !!-bound variables are split much more
  5493 aggressively, and safe_tac and clarify_tac now split such variables.
  5494 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5495 Note: the same holds for record_split_tac, which does the job of
  5496 split_all_tac for record fields.
  5497 
  5498 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5499 permanently to the default simpset using Addsplits just like
  5500 Addsimps. They can be removed via Delsplits just like
  5501 Delsimps. Lower-case versions are also available.
  5502 
  5503 * HOL/Simplifier: The rule split_if is now part of the default
  5504 simpset. This means that the simplifier will eliminate all occurrences
  5505 of if-then-else in the conclusion of a goal. To prevent this, you can
  5506 either remove split_if completely from the default simpset by
  5507 `Delsplits [split_if]' or remove it in a specific call of the
  5508 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5509 other case splitting rules to/from the default simpset: every datatype
  5510 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5511 t is the name of the datatype).
  5512 
  5513 * Classical reasoner / Simplifier combination: new force_tac (and
  5514 derivatives Force_tac, force) combines rewriting and classical
  5515 reasoning (and whatever other tools) similarly to auto_tac, but is
  5516 aimed to solve the given subgoal completely.
  5517 
  5518 
  5519 *** General ***
  5520 
  5521 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5522 and `goalw': the theory is no longer needed as an explicit argument -
  5523 the current theory context is used; assumptions are no longer returned
  5524 at the ML-level unless one of them starts with ==> or !!; it is
  5525 recommended to convert to these new commands using isatool fixgoal
  5526 (backup your sources first!);
  5527 
  5528 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5529 the current theory context, and 'theory' to lookup stored theories;
  5530 
  5531 * new theory section 'locale' for declaring constants, assumptions and
  5532 definitions that have local scope;
  5533 
  5534 * new theory section 'nonterminals' for purely syntactic types;
  5535 
  5536 * new theory section 'setup' for generic ML setup functions
  5537 (e.g. package initialization);
  5538 
  5539 * the distribution now includes Isabelle icons: see
  5540 lib/logo/isabelle-{small,tiny}.xpm;
  5541 
  5542 * isatool install - install binaries with absolute references to
  5543 ISABELLE_HOME/bin;
  5544 
  5545 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5546 
  5547 * print mode 'emacs' reserved for Isamode;
  5548 
  5549 * support multiple print (ast) translations per constant name;
  5550 
  5551 * theorems involving oracles are now printed with a suffixed [!];
  5552 
  5553 
  5554 *** HOL ***
  5555 
  5556 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5557 
  5558 * HOL/inductive package reorganized and improved: now supports mutual
  5559 definitions such as
  5560 
  5561   inductive EVEN ODD
  5562     intrs
  5563       null "0 : EVEN"
  5564       oddI "n : EVEN ==> Suc n : ODD"
  5565       evenI "n : ODD ==> Suc n : EVEN"
  5566 
  5567 new theorem list "elims" contains an elimination rule for each of the
  5568 recursive sets; inductive definitions now handle disjunctive premises
  5569 correctly (also ZF);
  5570 
  5571 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5572 "mutual_induct" no longer exists - the induction rule is always
  5573 contained in "induct";
  5574 
  5575 
  5576 * HOL/datatype package re-implemented and greatly improved: now
  5577 supports mutually recursive datatypes such as
  5578 
  5579   datatype
  5580     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5581             | SUM ('a aexp) ('a aexp)
  5582             | DIFF ('a aexp) ('a aexp)
  5583             | NUM 'a
  5584   and
  5585     'a bexp = LESS ('a aexp) ('a aexp)
  5586             | AND ('a bexp) ('a bexp)
  5587             | OR ('a bexp) ('a bexp)
  5588 
  5589 as well as indirectly recursive datatypes such as
  5590 
  5591   datatype
  5592     ('a, 'b) term = Var 'a
  5593                   | App 'b ((('a, 'b) term) list)
  5594 
  5595 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5596 induction on mutually / indirectly recursive datatypes.
  5597 
  5598 Primrec equations are now stored in theory and can be accessed via
  5599 <function_name>.simps.
  5600 
  5601 INCOMPATIBILITIES:
  5602 
  5603   - Theories using datatypes must now have theory Datatype as an
  5604     ancestor.
  5605   - The specific <typename>.induct_tac no longer exists - use the
  5606     generic induct_tac instead.
  5607   - natE has been renamed to nat.exhaust - use exhaust_tac
  5608     instead of res_inst_tac ... natE. Note that the variable
  5609     names in nat.exhaust differ from the names in natE, this
  5610     may cause some "fragile" proofs to fail.
  5611   - The theorems split_<typename>_case and split_<typename>_case_asm
  5612     have been renamed to <typename>.split and <typename>.split_asm.
  5613   - Since default sorts of type variables are now handled correctly,
  5614     some datatype definitions may have to be annotated with explicit
  5615     sort constraints.
  5616   - Primrec definitions no longer require function name and type
  5617     of recursive argument.
  5618 
  5619 Consider using isatool fixdatatype to adapt your theories and proof
  5620 scripts to the new package (backup your sources first!).
  5621 
  5622 
  5623 * HOL/record package: considerably improved implementation; now
  5624 includes concrete syntax for record types, terms, updates; theorems
  5625 for surjective pairing and splitting !!-bound record variables; proof
  5626 support is as follows:
  5627 
  5628   1) standard conversions (selectors or updates applied to record
  5629 constructor terms) are part of the standard simpset;
  5630 
  5631   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5632 made part of standard simpset and claset via addIffs;
  5633 
  5634   3) a tactic for record field splitting (record_split_tac) is part of
  5635 the standard claset (addSWrapper);
  5636 
  5637 To get a better idea about these rules you may retrieve them via
  5638 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5639 the name of your record type.
  5640 
  5641 The split tactic 3) conceptually simplifies by the following rule:
  5642 
  5643   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5644 
  5645 Thus any record variable that is bound by meta-all will automatically
  5646 blow up into some record constructor term, consequently the
  5647 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5648 solve record problems automatically.
  5649 
  5650 
  5651 * reorganized the main HOL image: HOL/Integ and String loaded by
  5652 default; theory Main includes everything;
  5653 
  5654 * automatic simplification of integer sums and comparisons, using cancellation;
  5655 
  5656 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5657 
  5658 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5659 
  5660 * many new identities for unions, intersections, set difference, etc.;
  5661 
  5662 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5663 called split_if, split_split, split_sum_case and split_nat_case (to go
  5664 with add/delsplits);
  5665 
  5666 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5667 (?x::unit) = (); this is made part of the default simpset, which COULD
  5668 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5669 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5670 unit_abs_eta_conv is added in order to counter the effect of
  5671 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5672 %u.f();
  5673 
  5674 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5675 makes more sense);
  5676 
  5677 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5678   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5679   disjointness reasoning but breaking a few old proofs.
  5680 
  5681 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5682 to 'converse' from 'inverse' (for compatibility with ZF and some
  5683 literature);
  5684 
  5685 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5686 the well-founded relation;
  5687 
  5688 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5689     Compl A.  The "Compl" syntax remains available as input syntax for this
  5690     release ONLY.
  5691 
  5692 * HOL/Update: new theory of function updates:
  5693     f(a:=b) == %x. if x=a then b else f x
  5694 may also be iterated as in f(a:=b,c:=d,...);
  5695 
  5696 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5697 
  5698 * HOL/List:
  5699   - new function list_update written xs[i:=v] that updates the i-th
  5700     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5701   - new function `upt' written [i..j(] which generates the list
  5702     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5703     bound write [i..j], which is a shorthand for [i..j+1(].
  5704   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5705 
  5706 * HOL/Arith:
  5707   - removed 'pred' (predecessor) function;
  5708   - generalized some theorems about n-1;
  5709   - many new laws about "div" and "mod";
  5710   - new laws about greatest common divisors (see theory ex/Primes);
  5711 
  5712 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5713 instead of "inverse";
  5714 
  5715 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5716   of the multiset ordering;
  5717 
  5718 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5719   (not included by default);
  5720 
  5721 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5722 
  5723 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5724   programs, i.e. different program variables may have different types.
  5725 
  5726 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5727   [previously, this check worked only if the rewrite rule was unconditional]
  5728   Now rew can involve either definitions or equalities (either == or =).
  5729 
  5730 
  5731 *** ZF ***
  5732 
  5733 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5734   only the theorems proved on ZF.ML;
  5735 
  5736 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5737   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5738   disjointness reasoning but breaking a few old proofs.
  5739 
  5740 * ZF/Update: new theory of function updates
  5741     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5742   may also be iterated as in f(a:=b,c:=d,...);
  5743 
  5744 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5745 
  5746 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5747   [previously, this check worked only if the rewrite rule was unconditional]
  5748   Now rew can involve either definitions or equalities (either == or =).
  5749 
  5750 * case_tac provided for compatibility with HOL
  5751     (like the old excluded_middle_tac, but with subgoals swapped)
  5752 
  5753 
  5754 *** Internal programming interfaces ***
  5755 
  5756 * Pure: several new basic modules made available for general use, see
  5757 also src/Pure/README;
  5758 
  5759 * improved the theory data mechanism to support encapsulation (data
  5760 kind name replaced by private Object.kind, acting as authorization
  5761 key); new type-safe user interface via functor TheoryDataFun; generic
  5762 print_data function becomes basically useless;
  5763 
  5764 * removed global_names compatibility flag -- all theory declarations
  5765 are qualified by default;
  5766 
  5767 * module Pure/Syntax now offers quote / antiquote translation
  5768 functions (useful for Hoare logic etc. with implicit dependencies);
  5769 see HOL/ex/Antiquote for an example use;
  5770 
  5771 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5772 cterm -> thm;
  5773 
  5774 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5775 subgoal;
  5776 
  5777 * Display.print_goals function moved to Locale.print_goals;
  5778 
  5779 * standard print function for goals supports current_goals_markers
  5780 variable for marking begin of proof, end of proof, start of goal; the
  5781 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5782 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5783 for example;
  5784 
  5785 
  5786 
  5787 New in Isabelle98 (January 1998)
  5788 --------------------------------
  5789 
  5790 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5791 
  5792 * changed lexical syntax of terms / types: dots made part of long
  5793 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5794 
  5795 * simpset (and claset) reference variable replaced by functions
  5796 simpset / simpset_ref;
  5797 
  5798 * no longer supports theory aliases (via merge) and non-trivial
  5799 implicit merge of thms' signatures;
  5800 
  5801 * most internal names of constants changed due to qualified names;
  5802 
  5803 * changed Pure/Sequence interface (see Pure/seq.ML);
  5804 
  5805 
  5806 *** General Changes ***
  5807 
  5808 * hierachically structured name spaces (for consts, types, axms, thms
  5809 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5810 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5811 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5812 long_names for fully qualified output names; NOTE: ML programs
  5813 (special tactics, packages etc.) referring to internal names may have
  5814 to be adapted to cope with fully qualified names; in case of severe
  5815 backward campatibility problems try setting 'global_names' at compile
  5816 time to have enrything declared within a flat name space; one may also
  5817 fine tune name declarations in theories via the 'global' and 'local'
  5818 section;
  5819 
  5820 * reimplemented the implicit simpset and claset using the new anytype
  5821 data filed in signatures; references simpset:simpset ref etc. are
  5822 replaced by functions simpset:unit->simpset and
  5823 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5824 to patch your ML files accordingly;
  5825 
  5826 * HTML output now includes theory graph data for display with Java
  5827 applet or isatool browser; data generated automatically via isatool
  5828 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5829 
  5830 * defs may now be conditional; improved rewrite_goals_tac to handle
  5831 conditional equations;
  5832 
  5833 * defs now admits additional type arguments, using TYPE('a) syntax;
  5834 
  5835 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5836 creates a new theory node; implicit merge of thms' signatures is
  5837 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5838 transfer:theory->thm->thm in (rare) cases;
  5839 
  5840 * improved handling of draft signatures / theories; draft thms (and
  5841 ctyps, cterms) are automatically promoted to real ones;
  5842 
  5843 * slightly changed interfaces for oracles: admit many per theory, named
  5844 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5845 
  5846 * print_goals: optional output of const types (set show_consts and
  5847 show_types);
  5848 
  5849 * improved output of warnings (###) and errors (***);
  5850 
  5851 * subgoal_tac displays a warning if the new subgoal has type variables;
  5852 
  5853 * removed old README and Makefiles;
  5854 
  5855 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5856 
  5857 * removed obsolete init_pps and init_database;
  5858 
  5859 * deleted the obsolete tactical STATE, which was declared by
  5860     fun STATE tacfun st = tacfun st st;
  5861 
  5862 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5863 (which abbreviates $HOME);
  5864 
  5865 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5866 use isatool fixseq to adapt your ML programs (this works for fully
  5867 qualified references to the Sequence structure only!);
  5868 
  5869 * use_thy no longer requires writable current directory; it always
  5870 reloads .ML *and* .thy file, if either one is out of date;
  5871 
  5872 
  5873 *** Classical Reasoner ***
  5874 
  5875 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5876 tactics that use classical reasoning to simplify a subgoal without
  5877 splitting it into several subgoals;
  5878 
  5879 * Safe_tac: like safe_tac but uses the default claset;
  5880 
  5881 
  5882 *** Simplifier ***
  5883 
  5884 * added simplification meta rules:
  5885     (asm_)(full_)simplify: simpset -> thm -> thm;
  5886 
  5887 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5888 logics (again);
  5889 
  5890 * added prems argument to simplification procedures;
  5891 
  5892 * HOL, FOL, ZF: added infix function `addsplits':
  5893   instead of `<simpset> setloop (split_tac <thms>)'
  5894   you can simply write `<simpset> addsplits <thms>'
  5895 
  5896 
  5897 *** Syntax ***
  5898 
  5899 * TYPE('a) syntax for type reflection terms;
  5900 
  5901 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5902 
  5903 * pretty printer: changed order of mixfix annotation preference (again!);
  5904 
  5905 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5906 
  5907 
  5908 *** HOL ***
  5909 
  5910 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5911   with `addloop' of the simplifier to faciliate case splitting in premises.
  5912 
  5913 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5914 
  5915 * HOL/Auth: new protocol proofs including some for the Internet
  5916   protocol TLS;
  5917 
  5918 * HOL/Map: new theory of `maps' a la VDM;
  5919 
  5920 * HOL/simplifier: simplification procedures nat_cancel_sums for
  5921 cancelling out common nat summands from =, <, <= (in)equalities, or
  5922 differences; simplification procedures nat_cancel_factor for
  5923 cancelling common factor from =, <, <= (in)equalities over natural
  5924 sums; nat_cancel contains both kinds of procedures, it is installed by
  5925 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  5926 
  5927 * HOL/simplifier: terms of the form
  5928   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  5929   are rewritten to
  5930   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  5931   and those of the form
  5932   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  5933   are rewritten to
  5934   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  5935 
  5936 * HOL/datatype
  5937   Each datatype `t' now comes with a theorem `split_t_case' of the form
  5938 
  5939   P(t_case f1 ... fn x) =
  5940      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  5941         ...
  5942        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  5943      )
  5944 
  5945   and a theorem `split_t_case_asm' of the form
  5946 
  5947   P(t_case f1 ... fn x) =
  5948     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  5949         ...
  5950        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  5951      )
  5952   which can be added to a simpset via `addsplits'. The existing theorems
  5953   expand_list_case and expand_option_case have been renamed to
  5954   split_list_case and split_option_case.
  5955 
  5956 * HOL/Arithmetic:
  5957   - `pred n' is automatically converted to `n-1'.
  5958     Users are strongly encouraged not to use `pred' any longer,
  5959     because it will disappear altogether at some point.
  5960   - Users are strongly encouraged to write "0 < n" rather than
  5961     "n ~= 0". Theorems and proof tools have been modified towards this
  5962     `standard'.
  5963 
  5964 * HOL/Lists:
  5965   the function "set_of_list" has been renamed "set" (and its theorems too);
  5966   the function "nth" now takes its arguments in the reverse order and
  5967   has acquired the infix notation "!" as in "xs!n".
  5968 
  5969 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  5970 
  5971 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  5972   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  5973 
  5974 * HOL/record: extensible records with schematic structural subtyping
  5975 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  5976 still lacks various theorems and concrete record syntax;
  5977 
  5978 
  5979 *** HOLCF ***
  5980 
  5981 * removed "axioms" and "generated by" sections;
  5982 
  5983 * replaced "ops" section by extended "consts" section, which is capable of
  5984   handling the continuous function space "->" directly;
  5985 
  5986 * domain package:
  5987   . proves theorems immediately and stores them in the theory,
  5988   . creates hierachical name space,
  5989   . now uses normal mixfix annotations (instead of cinfix...),
  5990   . minor changes to some names and values (for consistency),
  5991   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  5992   . separator between mutual domain defs: changed "," to "and",
  5993   . improved handling of sort constraints;  now they have to
  5994     appear on the left-hand side of the equations only;
  5995 
  5996 * fixed LAM <x,y,zs>.b syntax;
  5997 
  5998 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  5999 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6000 
  6001 
  6002 *** FOL and ZF ***
  6003 
  6004 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6005   with `addloop' of the simplifier to faciliate case splitting in premises.
  6006 
  6007 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6008 in HOL, they strip ALL and --> from proved theorems;
  6009 
  6010 
  6011 
  6012 New in Isabelle94-8 (May 1997)
  6013 ------------------------------
  6014 
  6015 *** General Changes ***
  6016 
  6017 * new utilities to build / run / maintain Isabelle etc. (in parts
  6018 still somewhat experimental); old Makefiles etc. still functional;
  6019 
  6020 * new 'Isabelle System Manual';
  6021 
  6022 * INSTALL text, together with ./configure and ./build scripts;
  6023 
  6024 * reimplemented type inference for greater efficiency, better error
  6025 messages and clean internal interface;
  6026 
  6027 * prlim command for dealing with lots of subgoals (an easier way of
  6028 setting goals_limit);
  6029 
  6030 
  6031 *** Syntax ***
  6032 
  6033 * supports alternative (named) syntax tables (parser and pretty
  6034 printer); internal interface is provided by add_modesyntax(_i);
  6035 
  6036 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6037 be used in conjunction with the Isabelle symbol font; uses the
  6038 "symbols" syntax table;
  6039 
  6040 * added token_translation interface (may translate name tokens in
  6041 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6042 the current print_mode); IMPORTANT: user print translation functions
  6043 are responsible for marking newly introduced bounds
  6044 (Syntax.mark_boundT);
  6045 
  6046 * token translations for modes "xterm" and "xterm_color" that display
  6047 names in bold, underline etc. or colors (which requires a color
  6048 version of xterm);
  6049 
  6050 * infixes may now be declared with names independent of their syntax;
  6051 
  6052 * added typed_print_translation (like print_translation, but may
  6053 access type of constant);
  6054 
  6055 
  6056 *** Classical Reasoner ***
  6057 
  6058 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6059 some limitations.  Blast_tac...
  6060   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6061   + ignores elimination rules that don't have the correct format
  6062         (the conclusion MUST be a formula variable)
  6063   + ignores types, which can make HOL proofs fail
  6064   + rules must not require higher-order unification, e.g. apply_type in ZF
  6065     [message "Function Var's argument not a bound variable" relates to this]
  6066   + its proof strategy is more general but can actually be slower
  6067 
  6068 * substitution with equality assumptions no longer permutes other
  6069 assumptions;
  6070 
  6071 * minor changes in semantics of addafter (now called addaltern); renamed
  6072 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6073 (and access functions for it);
  6074 
  6075 * improved combination of classical reasoner and simplifier:
  6076   + functions for handling clasimpsets
  6077   + improvement of addss: now the simplifier is called _after_ the
  6078     safe steps.
  6079   + safe variant of addss called addSss: uses safe simplifications
  6080     _during_ the safe steps. It is more complete as it allows multiple
  6081     instantiations of unknowns (e.g. with slow_tac).
  6082 
  6083 *** Simplifier ***
  6084 
  6085 * added interface for simplification procedures (functions that
  6086 produce *proven* rewrite rules on the fly, depending on current
  6087 redex);
  6088 
  6089 * ordering on terms as parameter (used for ordered rewriting);
  6090 
  6091 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6092 
  6093 * the solver is now split into a safe and an unsafe part.
  6094 This should be invisible for the normal user, except that the
  6095 functions setsolver and addsolver have been renamed to setSolver and
  6096 addSolver; added safe_asm_full_simp_tac;
  6097 
  6098 
  6099 *** HOL ***
  6100 
  6101 * a generic induction tactic `induct_tac' which works for all datatypes and
  6102 also for type `nat';
  6103 
  6104 * a generic case distinction tactic `exhaust_tac' which works for all
  6105 datatypes and also for type `nat';
  6106 
  6107 * each datatype comes with a function `size';
  6108 
  6109 * patterns in case expressions allow tuple patterns as arguments to
  6110 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6111 
  6112 * primrec now also works with type nat;
  6113 
  6114 * recdef: a new declaration form, allows general recursive functions to be
  6115 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6116 
  6117 * the constant for negation has been renamed from "not" to "Not" to
  6118 harmonize with FOL, ZF, LK, etc.;
  6119 
  6120 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6121 infinite lists;
  6122 
  6123 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6124 
  6125 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6126 problems in commutative rings, using axiomatic type classes for + and *;
  6127 
  6128 * more examples in HOL/MiniML and HOL/Auth;
  6129 
  6130 * more default rewrite rules for quantifiers, union/intersection;
  6131 
  6132 * a new constant `arbitrary == @x.False';
  6133 
  6134 * HOLCF/IOA replaces old HOL/IOA;
  6135 
  6136 * HOLCF changes: derived all rules and arities
  6137   + axiomatic type classes instead of classes
  6138   + typedef instead of faking type definitions
  6139   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6140   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6141   + eliminated the types void, one, tr
  6142   + use unit lift and bool lift (with translations) instead of one and tr
  6143   + eliminated blift from Lift3.thy (use Def instead of blift)
  6144   all eliminated rules are derived as theorems --> no visible changes ;
  6145 
  6146 
  6147 *** ZF ***
  6148 
  6149 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  6150 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  6151 as ZF_cs addSIs [equalityI];
  6152 
  6153 
  6154 
  6155 New in Isabelle94-7 (November 96)
  6156 ---------------------------------
  6157 
  6158 * allowing negative levels (as offsets) in prlev and choplev;
  6159 
  6160 * super-linear speedup for large simplifications;
  6161 
  6162 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  6163 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  6164 FAIL); can suppress it using the command Delsimps (ex_simps @
  6165 all_simps); De Morgan laws are also now included, by default;
  6166 
  6167 * improved printing of ==>  :  ~:
  6168 
  6169 * new object-logic "Sequents" adds linear logic, while replacing LK
  6170 and Modal (thanks to Sara Kalvala);
  6171 
  6172 * HOL/Auth: correctness proofs for authentication protocols;
  6173 
  6174 * HOL: new auto_tac combines rewriting and classical reasoning (many
  6175 examples on HOL/Auth);
  6176 
  6177 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  6178 the rewriter and classical reasoner simultaneously;
  6179 
  6180 * function uresult no longer returns theorems in "standard" format;
  6181 regain previous version by: val uresult = standard o uresult;
  6182 
  6183 
  6184 
  6185 New in Isabelle94-6
  6186 -------------------
  6187 
  6188 * oracles -- these establish an interface between Isabelle and trusted
  6189 external reasoners, which may deliver results as theorems;
  6190 
  6191 * proof objects (in particular record all uses of oracles);
  6192 
  6193 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  6194 
  6195 * "constdefs" section in theory files;
  6196 
  6197 * "primrec" section (HOL) no longer requires names;
  6198 
  6199 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  6200 
  6201 
  6202 
  6203 New in Isabelle94-5
  6204 -------------------
  6205 
  6206 * reduced space requirements;
  6207 
  6208 * automatic HTML generation from theories;
  6209 
  6210 * theory files no longer require "..." (quotes) around most types;
  6211 
  6212 * new examples, including two proofs of the Church-Rosser theorem;
  6213 
  6214 * non-curried (1994) version of HOL is no longer distributed;
  6215 
  6216 
  6217 
  6218 New in Isabelle94-4
  6219 -------------------
  6220 
  6221 * greatly reduced space requirements;
  6222 
  6223 * theory files (.thy) no longer require \...\ escapes at line breaks;
  6224 
  6225 * searchable theorem database (see the section "Retrieving theorems" on
  6226 page 8 of the Reference Manual);
  6227 
  6228 * new examples, including Grabczewski's monumental case study of the
  6229 Axiom of Choice;
  6230 
  6231 * The previous version of HOL renamed to Old_HOL;
  6232 
  6233 * The new version of HOL (previously called CHOL) uses a curried syntax
  6234 for functions.  Application looks like f a b instead of f(a,b);
  6235 
  6236 * Mutually recursive inductive definitions finally work in HOL;
  6237 
  6238 * In ZF, pattern-matching on tuples is now available in all abstractions and
  6239 translates to the operator "split";
  6240 
  6241 
  6242 
  6243 New in Isabelle94-3
  6244 -------------------
  6245 
  6246 * new infix operator, addss, allowing the classical reasoner to
  6247 perform simplification at each step of its search.  Example:
  6248         fast_tac (cs addss ss)
  6249 
  6250 * a new logic, CHOL, the same as HOL, but with a curried syntax
  6251 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  6252 look like (a,b) instead of <a,b>;
  6253 
  6254 * PLEASE NOTE: CHOL will eventually replace HOL!
  6255 
  6256 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  6257 It translates to the operator "split".  A new theory of integers is available;
  6258 
  6259 * In ZF, integer numerals now denote two's-complement binary integers.
  6260 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  6261