NEWS
author wenzelm
Thu Jul 09 22:01:41 2009 +0200 (2009-07-09)
changeset 31971 8c1b845ed105
parent 31901 e280491f36b8
child 31997 de0d280c31a7
child 32064 53ca12ff305d
permissions -rw-r--r--
renamed functor TableFun to Table, and GraphFun to Graph;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    10 one backslash should be used, even in ML sources.
    11 
    12 
    13 *** Pure ***
    14 
    15 * On instantiation of classes, remaining undefined class parameters
    16 are formally declared.  INCOMPATIBILITY.
    17 
    18 
    19 *** HOL ***
    20 
    21 * Class semiring_div requires superclass no_zero_divisors and proof of
    22 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    23 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    24 generalized to class semiring_div, subsuming former theorems
    25 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    26 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    27 INCOMPATIBILITY.
    28 
    29 * Power operations on relations and functions are now one dedicate
    30 constant compow with infix syntax "^^".  Power operations on
    31 multiplicative monoids retains syntax "^" and is now defined generic
    32 in class power.  INCOMPATIBILITY.
    33 
    34 * ML antiquotation @{code_datatype} inserts definition of a datatype
    35 generated by the code generator; see Predicate.thy for an example.
    36 
    37 * New method "linarith" invokes existing linear arithmetic decision
    38 procedure only.
    39 
    40 * Implementation of quickcheck using generic code generator; default
    41 generators are provided for all suitable HOL types, records and
    42 datatypes.
    43 
    44 * Constants Set.Pow and Set.image now with authentic syntax;
    45 object-logic definitions Set.Pow_def and Set.image_def.
    46 INCOMPATIBILITY.
    47 
    48 * Renamed theorems:
    49 Suc_eq_add_numeral_1 -> Suc_eq_plus1
    50 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
    51 Suc_plus1 -> Suc_eq_plus1
    52 
    53 * New sledgehammer option "Full Types" in Proof General settings menu.
    54 Causes full type information to be output to the ATPs.  This slows
    55 ATPs down considerably but eliminates a source of unsound "proofs"
    56 that fail later.
    57 
    58 * Discontinued ancient tradition to suffix certain ML module names
    59 with "_package", e.g.:
    60 
    61     DatatypePackage ~> Datatype
    62     InductivePackage ~> Inductive
    63 
    64     etc.
    65 
    66 INCOMPATIBILITY.
    67 
    68 * NewNumberTheory: Jeremy Avigad's new version of part of
    69 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
    70 
    71 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
    72 
    73 * Abbreviation "arbitrary" of "undefined" has disappeared; use
    74 "undefined" directly.  INCOMPATIBILITY.
    75 
    76 * New evaluator "approximate" approximates an real valued term using
    77 the same method as the approximation method.
    78 
    79 * Method "approximate" supports now arithmetic expressions as
    80 boundaries of intervals and implements interval splitting and Taylor
    81 series expansion.
    82 
    83 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
    84 the theorems in DERIV_intros assumes composition with an additional
    85 function and matches a variable to the derivative, which has to be
    86 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
    87 the derivative of most elementary terms.
    88 
    89 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
    90 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
    91 
    92 
    93 *** ML ***
    94 
    95 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
    96 functors have their own ML name space there is no point to mark them
    97 separately.)  Minor INCOMPATIBILITY.
    98 
    99 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   100 
   101 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   102 cominators for "args".  INCOMPATIBILITY, need to use simplified
   103 Attrib/Method.setup introduced in Isabelle2009.
   104 
   105 
   106 *** System ***
   107 
   108 * Discontinued support for Poly/ML 4.x versions.
   109 
   110 * Removed "compress" option from isabelle-process and isabelle usedir;
   111 this is always enabled.
   112 
   113 
   114 
   115 New in Isabelle2009 (April 2009)
   116 --------------------------------
   117 
   118 *** General ***
   119 
   120 * Simplified main Isabelle executables, with less surprises on
   121 case-insensitive file-systems (such as Mac OS).
   122 
   123   - The main Isabelle tool wrapper is now called "isabelle" instead of
   124     "isatool."
   125 
   126   - The former "isabelle" alias for "isabelle-process" has been
   127     removed (should rarely occur to regular users).
   128 
   129   - The former "isabelle-interface" and its alias "Isabelle" have been
   130     removed (interfaces are now regular Isabelle tools).
   131 
   132 Within scripts and make files, the Isabelle environment variables
   133 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   134 respectively.  (The latter are still available as legacy feature.)
   135 
   136 The old isabelle-interface wrapper could react in confusing ways if
   137 the interface was uninstalled or changed otherwise.  Individual
   138 interface tool configuration is now more explicit, see also the
   139 Isabelle system manual.  In particular, Proof General is now available
   140 via "isabelle emacs".
   141 
   142 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   143 purge installed copies of Isabelle executables and re-run "isabelle
   144 install -p ...", or use symlinks.
   145 
   146 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   147 old ~/isabelle, which was slightly non-standard and apt to cause
   148 surprises on case-insensitive file-systems (such as Mac OS).
   149 
   150 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   151 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   152 care is required when using older releases of Isabelle.  Note that
   153 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   154 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   155 
   156 * Proofs of fully specified statements are run in parallel on
   157 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   158 a regular 4-core machine, if the initial heap space is made reasonably
   159 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   160 
   161 * The main reference manuals ("isar-ref", "implementation", and
   162 "system") have been updated and extended.  Formally checked references
   163 as hyperlinks are now available uniformly.
   164 
   165 
   166 *** Pure ***
   167 
   168 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   169 respects.  The most important changes are listed below.  See the
   170 Tutorial on Locales ("locales" manual) for details.
   171 
   172 - In locale expressions, instantiation replaces renaming.  Parameters
   173 must be declared in a for clause.  To aid compatibility with previous
   174 parameter inheritance, in locale declarations, parameters that are not
   175 'touched' (instantiation position "_" or omitted) are implicitly added
   176 with their syntax at the beginning of the for clause.
   177 
   178 - Syntax from abbreviations and definitions in locales is available in
   179 locale expressions and context elements.  The latter is particularly
   180 useful in locale declarations.
   181 
   182 - More flexible mechanisms to qualify names generated by locale
   183 expressions.  Qualifiers (prefixes) may be specified in locale
   184 expressions, and can be marked as mandatory (syntax: "name!:") or
   185 optional (syntax "name?:").  The default depends for plain "name:"
   186 depends on the situation where a locale expression is used: in
   187 commands 'locale' and 'sublocale' prefixes are optional, in
   188 'interpretation' and 'interpret' prefixes are mandatory.  The old
   189 implicit qualifiers derived from the parameter names of a locale are
   190 no longer generated.
   191 
   192 - Command "sublocale l < e" replaces "interpretation l < e".  The
   193 instantiation clause in "interpretation" and "interpret" (square
   194 brackets) is no longer available.  Use locale expressions.
   195 
   196 - When converting proof scripts, mandatory qualifiers in
   197 'interpretation' and 'interpret' should be retained by default, even
   198 if this is an INCOMPATIBILITY compared to former behavior.  In the
   199 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   200 in locale expressions range over a single locale instance only.
   201 
   202 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   203 In existing theorem specifications replace the includes element by the
   204 respective context elements of the included locale, omitting those
   205 that are already present in the theorem specification.  Multiple
   206 assume elements of a locale should be replaced by a single one
   207 involving the locale predicate.  In the proof body, declarations (most
   208 notably theorems) may be regained by interpreting the respective
   209 locales in the proof context as required (command "interpret").
   210 
   211 If using "includes" in replacement of a target solely because the
   212 parameter types in the theorem are not as general as in the target,
   213 consider declaring a new locale with additional type constraints on
   214 the parameters (context element "constrains").
   215 
   216 - Discontinued "locale (open)".  INCOMPATIBILITY.
   217 
   218 - Locale interpretation commands no longer attempt to simplify goal.
   219 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   220 methods intro_locales and unfold_locales to clarify.
   221 
   222 - Locale interpretation commands no longer accept interpretation
   223 attributes.  INCOMPATIBILITY.
   224 
   225 * Class declaration: so-called "base sort" must not be given in import
   226 list any longer, but is inferred from the specification.  Particularly
   227 in HOL, write
   228 
   229     class foo = ...
   230 
   231 instead of
   232 
   233     class foo = type + ...
   234 
   235 * Class target: global versions of theorems stemming do not carry a
   236 parameter prefix any longer.  INCOMPATIBILITY.
   237 
   238 * Class 'instance' command no longer accepts attached definitions.
   239 INCOMPATIBILITY, use proper 'instantiation' target instead.
   240 
   241 * Recovered hiding of consts, which was accidentally broken in
   242 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   243 makes c inaccessible; consider using ``hide (open) const c'' instead.
   244 
   245 * Slightly more coherent Pure syntax, with updated documentation in
   246 isar-ref manual.  Removed locales meta_term_syntax and
   247 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   248 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   249 directly in regular applications.
   250 
   251 * There is a new syntactic category "float_const" for signed decimal
   252 fractions (e.g. 123.45 or -123.45).
   253 
   254 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   255 interface with 'setup' command instead.
   256 
   257 * Command 'local_setup' is similar to 'setup', but operates on a local
   258 theory context.
   259 
   260 * The 'axiomatization' command now only works within a global theory
   261 context.  INCOMPATIBILITY.
   262 
   263 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   264 hypotheses.  Sorts required in the course of reasoning need to be
   265 covered by the constraints in the initial statement, completed by the
   266 type instance information of the background theory.  Non-trivial sort
   267 hypotheses, which rarely occur in practice, may be specified via
   268 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   269 
   270   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   271 
   272 The result contains an implicit sort hypotheses as before --
   273 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   274 normalization.
   275 
   276 * Generalized Isar history, with support for linear undo, direct state
   277 addressing etc.
   278 
   279 * Changed defaults for unify configuration options:
   280 
   281   unify_trace_bound = 50 (formerly 25)
   282   unify_search_bound = 60 (formerly 30)
   283 
   284 * Different bookkeeping for code equations (INCOMPATIBILITY):
   285 
   286   a) On theory merge, the last set of code equations for a particular
   287      constant is taken (in accordance with the policy applied by other
   288      parts of the code generator framework).
   289 
   290   b) Code equations stemming from explicit declarations (e.g. code
   291      attribute) gain priority over default code equations stemming
   292      from definition, primrec, fun etc.
   293 
   294 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   295 
   296 * Unified theorem tables for both code generators.  Thus [code
   297 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   298 
   299 * Command 'find_consts' searches for constants based on type and name
   300 patterns, e.g.
   301 
   302     find_consts "_ => bool"
   303 
   304 By default, matching is against subtypes, but it may be restricted to
   305 the whole type.  Searching by name is possible.  Multiple queries are
   306 conjunctive and queries may be negated by prefixing them with a
   307 hyphen:
   308 
   309     find_consts strict: "_ => bool" name: "Int" -"int => int"
   310 
   311 * New 'find_theorems' criterion "solves" matches theorems that
   312 directly solve the current goal (modulo higher-order unification).
   313 
   314 * Auto solve feature for main theorem statements: whenever a new goal
   315 is stated, "find_theorems solves" is called; any theorems that could
   316 solve the lemma directly are listed as part of the goal state.
   317 Cf. associated options in Proof General Isabelle settings menu,
   318 enabled by default, with reasonable timeout for pathological cases of
   319 higher-order unification.
   320 
   321 
   322 *** Document preparation ***
   323 
   324 * Antiquotation @{lemma} now imitates a regular terminal proof,
   325 demanding keyword 'by' and supporting the full method expression
   326 syntax just like the Isar command 'by'.
   327 
   328 
   329 *** HOL ***
   330 
   331 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   332 points Main and Complex_Main remain as before.
   333 
   334 * Logic image HOL-Plain provides a minimal HOL with the most important
   335 tools available (inductive, datatype, primrec, ...).  This facilitates
   336 experimentation and tool development.  Note that user applications
   337 (and library theories) should never refer to anything below theory
   338 Main, as before.
   339 
   340 * Logic image HOL-Main stops at theory Main, and thus facilitates
   341 experimentation due to shorter build times.
   342 
   343 * Logic image HOL-NSA contains theories of nonstandard analysis which
   344 were previously part of former HOL-Complex.  Entry point Hyperreal
   345 remains valid, but theories formerly using Complex_Main should now use
   346 new entry point Hypercomplex.
   347 
   348 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   349 Posix processes.  Avoids potentially expensive forking of the ML
   350 process.  New thread-based implementation also works on non-Unix
   351 platforms (Cygwin).  Provers are no longer hardwired, but defined
   352 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   353 commands are covered in the isar-ref manual.
   354 
   355 * Wrapper scripts for remote SystemOnTPTP service allows to use
   356 sledgehammer without local ATP installation (Vampire etc.). Other
   357 provers may be included via suitable ML wrappers, see also
   358 src/HOL/ATP_Linkup.thy.
   359 
   360 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   361 menu.
   362 
   363 * The metis method no longer fails because the theorem is too trivial
   364 (contains the empty clause).
   365 
   366 * The metis method now fails in the usual manner, rather than raising
   367 an exception, if it determines that it cannot prove the theorem.
   368 
   369 * Method "coherent" implements a prover for coherent logic (see also
   370 src/Tools/coherent.ML).
   371 
   372 * Constants "undefined" and "default" replace "arbitrary".  Usually
   373 "undefined" is the right choice to replace "arbitrary", though
   374 logically there is no difference.  INCOMPATIBILITY.
   375 
   376 * Command "value" now integrates different evaluation mechanisms.  The
   377 result of the first successful evaluation mechanism is printed.  In
   378 square brackets a particular named evaluation mechanisms may be
   379 specified (currently, [SML], [code] or [nbe]).  See further
   380 src/HOL/ex/Eval_Examples.thy.
   381 
   382 * Normalization by evaluation now allows non-leftlinear equations.
   383 Declare with attribute [code nbe].
   384 
   385 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   386 as the structured Isar versions "cases" and "induct", cf. the
   387 corresponding "cases" and "induct" attributes.  Mutual induction rules
   388 are now presented as a list of individual projections
   389 (e.g. foo_bar.inducts for types foo and bar); the old format with
   390 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   391 rare situations a different rule is selected --- notably nested tuple
   392 elimination instead of former prod.exhaust: use explicit (case_tac t
   393 rule: prod.exhaust) here.
   394 
   395 * Attributes "cases", "induct", "coinduct" support "del" option.
   396 
   397 * Removed fact "case_split_thm", which duplicates "case_split".
   398 
   399 * The option datatype has been moved to a new theory Option.  Renamed
   400 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   401 
   402 * New predicate "strict_mono" classifies strict functions on partial
   403 orders.  With strict functions on linear orders, reasoning about
   404 (in)equalities is facilitated by theorems "strict_mono_eq",
   405 "strict_mono_less_eq" and "strict_mono_less".
   406 
   407 * Some set operations are now proper qualified constants with
   408 authentic syntax.  INCOMPATIBILITY:
   409 
   410     op Int ~>   Set.Int
   411     op Un ~>    Set.Un
   412     INTER ~>    Set.INTER
   413     UNION ~>    Set.UNION
   414     Inter ~>    Set.Inter
   415     Union ~>    Set.Union
   416     {} ~>       Set.empty
   417     UNIV ~>     Set.UNIV
   418 
   419 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   420 theory Set.
   421 
   422 * Auxiliary class "itself" has disappeared -- classes without any
   423 parameter are treated as expected by the 'class' command.
   424 
   425 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   426 
   427 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   428 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   429 
   430 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   431 method "approximation".  It proves formulas on real values by using
   432 interval arithmetic.  In the formulas are also the transcendental
   433 functions sin, cos, tan, atan, ln, exp and the constant pi are
   434 allowed. For examples see
   435 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   436 
   437 * Theory "Reflection" now resides in HOL/Library.
   438 
   439 * Entry point to Word library now simply named "Word".
   440 INCOMPATIBILITY.
   441 
   442 * Made source layout more coherent with logical distribution
   443 structure:
   444 
   445     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   446     src/HOL/Library/Code_Message.thy ~> src/HOL/
   447     src/HOL/Library/GCD.thy ~> src/HOL/
   448     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   449     src/HOL/Library/Parity.thy ~> src/HOL/
   450     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   451     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   452     src/HOL/Real/Lubs.thy ~> src/HOL/
   453     src/HOL/Real/PReal.thy ~> src/HOL/
   454     src/HOL/Real/Rational.thy ~> src/HOL/
   455     src/HOL/Real/RComplete.thy ~> src/HOL/
   456     src/HOL/Real/RealDef.thy ~> src/HOL/
   457     src/HOL/Real/RealPow.thy ~> src/HOL/
   458     src/HOL/Real/Real.thy ~> src/HOL/
   459     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   460     src/HOL/Complex/Complex.thy ~> src/HOL/
   461     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   462     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   463     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   464     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   465     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   466     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   467     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   468     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   469     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   470     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   471     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   472     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   473     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   474     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   475     src/HOL/Real/Float ~> src/HOL/Library/
   476     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   477     src/HOL/Real/RealVector.thy ~> src/HOL/
   478 
   479     src/HOL/arith_data.ML ~> src/HOL/Tools
   480     src/HOL/hologic.ML ~> src/HOL/Tools
   481     src/HOL/simpdata.ML ~> src/HOL/Tools
   482     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   483     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   484     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   485     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   486     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   487     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   488     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   489 
   490     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   491     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   492     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   493     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   494     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   495     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   496 
   497 * If methods "eval" and "evaluation" encounter a structured proof
   498 state with !!/==>, only the conclusion is evaluated to True (if
   499 possible), avoiding strange error messages.
   500 
   501 * Method "sizechange" automates termination proofs using (a
   502 modification of) the size-change principle.  Requires SAT solver.  See
   503 src/HOL/ex/Termination.thy for examples.
   504 
   505 * Simplifier: simproc for let expressions now unfolds if bound
   506 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   507 
   508 * Method "arith": Linear arithmetic now ignores all inequalities when
   509 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   510 
   511 * New attribute "arith" for facts that should always be used
   512 automatically by arithmetic. It is intended to be used locally in
   513 proofs, e.g.
   514 
   515   assumes [arith]: "x > 0"
   516 
   517 Global usage is discouraged because of possible performance impact.
   518 
   519 * New classes "top" and "bot" with corresponding operations "top" and
   520 "bot" in theory Orderings; instantiation of class "complete_lattice"
   521 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   522 
   523 * Changed definition lemma "less_fun_def" in order to provide an
   524 instance for preorders on functions; use lemma "less_le" instead.
   525 INCOMPATIBILITY.
   526 
   527 * Theory Orderings: class "wellorder" moved here, with explicit
   528 induction rule "less_induct" as assumption.  For instantiation of
   529 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   530 INCOMPATIBILITY.
   531 
   532 * Theory Orderings: added class "preorder" as superclass of "order".
   533 INCOMPATIBILITY: Instantiation proofs for order, linorder
   534 etc. slightly changed.  Some theorems named order_class.* now named
   535 preorder_class.*.
   536 
   537 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   538 "diag" to "Id_on".
   539 
   540 * Theory Finite_Set: added a new fold combinator of type
   541 
   542   ('a => 'b => 'b) => 'b => 'a set => 'b
   543 
   544 Occasionally this is more convenient than the old fold combinator
   545 which is now defined in terms of the new one and renamed to
   546 fold_image.
   547 
   548 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   549 and "ring_simps" have been replaced by "algebra_simps" (which can be
   550 extended with further lemmas!).  At the moment both still exist but
   551 the former will disappear at some point.
   552 
   553 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   554 class recpower.  Type-specific simp rules for various recpower types
   555 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   556 
   557 rat_power_0    -> power_0
   558 rat_power_Suc  -> power_Suc
   559 realpow_0      -> power_0
   560 realpow_Suc    -> power_Suc
   561 complexpow_0   -> power_0
   562 complexpow_Suc -> power_Suc
   563 power_poly_0   -> power_0
   564 power_poly_Suc -> power_Suc
   565 
   566 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   567 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   568 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   569 of lemmas from Divides has been generalized from nat to class
   570 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   571 renames resulting from duplicate elimination:
   572 
   573     dvd_def_mod ~>          dvd_eq_mod_eq_0
   574     zero_dvd_iff ~>         dvd_0_left_iff
   575     dvd_0 ~>                dvd_0_right
   576     DIVISION_BY_ZERO_DIV ~> div_by_0
   577     DIVISION_BY_ZERO_MOD ~> mod_by_0
   578     mult_div ~>             div_mult_self2_is_id
   579     mult_mod ~>             mod_mult_self2_is_0
   580 
   581 * Theory IntDiv: removed many lemmas that are instances of class-based
   582 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   583 rename old lemmas as follows:
   584 
   585 dvd_diff               -> nat_dvd_diff
   586 dvd_zminus_iff         -> dvd_minus_iff
   587 mod_add1_eq            -> mod_add_eq
   588 mod_mult1_eq           -> mod_mult_right_eq
   589 mod_mult1_eq'          -> mod_mult_left_eq
   590 mod_mult_distrib_mod   -> mod_mult_eq
   591 nat_mod_add_left_eq    -> mod_add_left_eq
   592 nat_mod_add_right_eq   -> mod_add_right_eq
   593 nat_mod_div_trivial    -> mod_div_trivial
   594 nat_mod_mod_trivial    -> mod_mod_trivial
   595 zdiv_zadd_self1        -> div_add_self1
   596 zdiv_zadd_self2        -> div_add_self2
   597 zdiv_zmult_self1       -> div_mult_self2_is_id
   598 zdiv_zmult_self2       -> div_mult_self1_is_id
   599 zdvd_triv_left         -> dvd_triv_left
   600 zdvd_triv_right        -> dvd_triv_right
   601 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   602 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   603 zmod_zadd_left_eq      -> mod_add_left_eq
   604 zmod_zadd_right_eq     -> mod_add_right_eq
   605 zmod_zadd_self1        -> mod_add_self1
   606 zmod_zadd_self2        -> mod_add_self2
   607 zmod_zadd1_eq          -> mod_add_eq
   608 zmod_zdiff1_eq         -> mod_diff_eq
   609 zmod_zdvd_zmod         -> mod_mod_cancel
   610 zmod_zmod_cancel       -> mod_mod_cancel
   611 zmod_zmult_self1       -> mod_mult_self2_is_0
   612 zmod_zmult_self2       -> mod_mult_self1_is_0
   613 zmod_1                 -> mod_by_1
   614 zdiv_1                 -> div_by_1
   615 zdvd_abs1              -> abs_dvd_iff
   616 zdvd_abs2              -> dvd_abs_iff
   617 zdvd_refl              -> dvd_refl
   618 zdvd_trans             -> dvd_trans
   619 zdvd_zadd              -> dvd_add
   620 zdvd_zdiff             -> dvd_diff
   621 zdvd_zminus_iff        -> dvd_minus_iff
   622 zdvd_zminus2_iff       -> minus_dvd_iff
   623 zdvd_zmultD            -> dvd_mult_right
   624 zdvd_zmultD2           -> dvd_mult_left
   625 zdvd_zmult_mono        -> mult_dvd_mono
   626 zdvd_0_right           -> dvd_0_right
   627 zdvd_0_left            -> dvd_0_left_iff
   628 zdvd_1_left            -> one_dvd
   629 zminus_dvd_iff         -> minus_dvd_iff
   630 
   631 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   632 
   633 * The real numbers offer decimal input syntax: 12.34 is translated
   634 into 1234/10^2. This translation is not reversed upon output.
   635 
   636 * Theory Library/Polynomial defines an abstract type 'a poly of
   637 univariate polynomials with coefficients of type 'a.  In addition to
   638 the standard ring operations, it also supports div and mod.  Code
   639 generation is also supported, using list-style constructors.
   640 
   641 * Theory Library/Inner_Product defines a class of real_inner for real
   642 inner product spaces, with an overloaded operation inner :: 'a => 'a
   643 => real.  Class real_inner is a subclass of real_normed_vector from
   644 theory RealVector.
   645 
   646 * Theory Library/Product_Vector provides instances for the product
   647 type 'a * 'b of several classes from RealVector and Inner_Product.
   648 Definitions of addition, subtraction, scalar multiplication, norms,
   649 and inner products are included.
   650 
   651 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   652 addition to the field operations, numerals and case syntax are also
   653 supported.
   654 
   655 * Theory Library/Diagonalize provides constructive version of Cantor's
   656 first diagonalization argument.
   657 
   658 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   659 zlcm (for int); carried together from various gcd/lcm developements in
   660 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   661 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   662 may recover tupled syntax as follows:
   663 
   664     hide (open) const gcd
   665     abbreviation gcd where
   666       "gcd == (%(a, b). GCD.gcd a b)"
   667     notation (output)
   668       GCD.gcd ("gcd '(_, _')")
   669 
   670 The same works for lcm, zgcd, zlcm.
   671 
   672 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   673 instantiations for algebraic structures.  Removed some duplicate
   674 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   675 
   676 * ML antiquotation @{code} takes a constant as argument and generates
   677 corresponding code in background and inserts name of the corresponding
   678 resulting ML value/function/datatype constructor binding in place.
   679 All occurrences of @{code} with a single ML block are generated
   680 simultaneously.  Provides a generic and safe interface for
   681 instrumentalizing code generation.  See
   682 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   683 In future you ought to refrain from ad-hoc compiling generated SML
   684 code on the ML toplevel.  Note that (for technical reasons) @{code}
   685 cannot refer to constants for which user-defined serializations are
   686 set.  Refer to the corresponding ML counterpart directly in that
   687 cases.
   688 
   689 * Command 'rep_datatype': instead of theorem names the command now
   690 takes a list of terms denoting the constructors of the type to be
   691 represented as datatype.  The characteristic theorems have to be
   692 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   693 have disappeared in favour of existing ones:
   694 
   695     unit_induct                 ~> unit.induct
   696     prod_induct                 ~> prod.induct
   697     sum_induct                  ~> sum.induct
   698     Suc_Suc_eq                  ~> nat.inject
   699     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   700 
   701 
   702 *** HOL-Algebra ***
   703 
   704 * New locales for orders and lattices where the equivalence relation
   705 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   706 locales use a record structure with field eq for the equivalence.
   707 
   708 * New theory of factorial domains.
   709 
   710 * Units_l_inv and Units_r_inv are now simp rules by default.
   711 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   712 and/or r_inv will now also require deletion of these lemmas.
   713 
   714 * Renamed the following theorems, INCOMPATIBILITY:
   715 
   716 UpperD ~> Upper_memD
   717 LowerD ~> Lower_memD
   718 least_carrier ~> least_closed
   719 greatest_carrier ~> greatest_closed
   720 greatest_Lower_above ~> greatest_Lower_below
   721 one_zero ~> carrier_one_zero
   722 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   723 
   724 
   725 *** HOL-Nominal ***
   726 
   727 * Nominal datatypes can now contain type-variables.
   728 
   729 * Commands 'nominal_inductive' and 'equivariance' work with local
   730 theory targets.
   731 
   732 * Nominal primrec can now works with local theory targets and its
   733 specification syntax now conforms to the general format as seen in
   734 'inductive' etc.
   735 
   736 * Method "perm_simp" honours the standard simplifier attributes
   737 (no_asm), (no_asm_use) etc.
   738 
   739 * The new predicate #* is defined like freshness, except that on the
   740 left hand side can be a set or list of atoms.
   741 
   742 * Experimental command 'nominal_inductive2' derives strong induction
   743 principles for inductive definitions.  In contrast to
   744 'nominal_inductive', which can only deal with a fixed number of
   745 binders, it can deal with arbitrary expressions standing for sets of
   746 atoms to be avoided.  The only inductive definition we have at the
   747 moment that needs this generalisation is the typing rule for Lets in
   748 the algorithm W:
   749 
   750  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   751  -----------------------------------------------------------------
   752          Gamma |- Let x be t1 in t2 : T2
   753 
   754 In this rule one wants to avoid all the binders that are introduced by
   755 "close Gamma T1".  We are looking for other examples where this
   756 feature might be useful.  Please let us know.
   757 
   758 
   759 *** HOLCF ***
   760 
   761 * Reimplemented the simplification procedure for proving continuity
   762 subgoals.  The new simproc is extensible; users can declare additional
   763 continuity introduction rules with the attribute [cont2cont].
   764 
   765 * The continuity simproc now uses a different introduction rule for
   766 solving continuity subgoals on terms with lambda abstractions.  In
   767 some rare cases the new simproc may fail to solve subgoals that the
   768 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   769 Potential INCOMPATIBILITY.
   770 
   771 * Command 'fixrec': specification syntax now conforms to the general
   772 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   773 examples.  INCOMPATIBILITY.
   774 
   775 
   776 *** ZF ***
   777 
   778 * Proof of Zorn's Lemma for partial orders.
   779 
   780 
   781 *** ML ***
   782 
   783 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   784 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   785 depends on multithreading, so timouts will not work before Poly/ML
   786 5.2.1!
   787 
   788 * High-level support for concurrent ML programming, see
   789 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   790 particularly convenient to organize independent functional
   791 computations.  The concept of "synchronized variables" provides a
   792 higher-order interface for components with shared state, avoiding the
   793 delicate details of mutexes and condition variables.  (Requires
   794 Poly/ML 5.2.1 or later.)
   795 
   796 * ML bindings produced via Isar commands are stored within the Isar
   797 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   798 become thread-safe and work with undo as expected (concerning
   799 top-level bindings, not side-effects on global references).
   800 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   801 compiler at runtime; really global bindings need to be given outside a
   802 theory.  (Requires Poly/ML 5.2 or later.)
   803 
   804 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   805 context.  Top-level ML bindings are stored within the proof context in
   806 a purely sequential fashion, disregarding the nested proof structure.
   807 ML bindings introduced by 'ML_prf' are discarded at the end of the
   808 proof.  (Requires Poly/ML 5.2 or later.)
   809 
   810 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   811 and Method.setup, as well as Isar commands 'attribute_setup' and
   812 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   813 existing code accordingly, or use plain 'setup' together with old
   814 Method.add_method.
   815 
   816 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   817 to 'a -> thm, while results are always tagged with an authentic oracle
   818 name.  The Isar command 'oracle' is now polymorphic, no argument type
   819 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   820 accordingly.  Note that extra performance may be gained by producing
   821 the cterm carefully, avoiding slow Thm.cterm_of.
   822 
   823 * Simplified interface for defining document antiquotations via
   824 ThyOutput.antiquotation, ThyOutput.output, and optionally
   825 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   826 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   827 examples.
   828 
   829 * More systematic treatment of long names, abstract name bindings, and
   830 name space operations.  Basic operations on qualified names have been
   831 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   832 Long_Name.append.  Old type bstring has been mostly replaced by
   833 abstract type binding (see structure Binding), which supports precise
   834 qualification by packages and local theory targets, as well as proper
   835 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   836 bstring values into Binding.name, or better pass through abstract
   837 bindings everywhere.  See further src/Pure/General/long_name.ML,
   838 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   839 
   840 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   841 LocalTheory.note etc.) now refer to the *full* internal name, not the
   842 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   843 
   844 * Disposed old type and term read functions (Sign.read_def_typ,
   845 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   846 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   847 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   848 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   849 resort for legacy applications.
   850 
   851 * Disposed old declarations, tactics, tactic combinators that refer to
   852 the simpset or claset of an implicit theory (such as Addsimps,
   853 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   854 embedded ML text, or local_simpset_of with a proper context passed as
   855 explicit runtime argument.
   856 
   857 * Rules and tactics that read instantiations (read_instantiate,
   858 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   859 context, which is required for parsing and type-checking.  Moreover,
   860 the variables are specified as plain indexnames, not string encodings
   861 thereof.  INCOMPATIBILITY.
   862 
   863 * Generic Toplevel.add_hook interface allows to analyze the result of
   864 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   865 for theorem dependency output of transactions resulting in a new
   866 theory state.
   867 
   868 * ML antiquotations: block-structured compilation context indicated by
   869 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   870 
   871   @{binding name}                         - basic name binding
   872   @{let ?pat = term}                      - term abbreviation (HO matching)
   873   @{note name = fact}                     - fact abbreviation
   874   @{thm fact}                             - singleton fact (with attributes)
   875   @{thms fact}                            - general fact (with attributes)
   876   @{lemma prop by method}                 - singleton goal
   877   @{lemma prop by meth1 meth2}            - singleton goal
   878   @{lemma prop1 ... propN by method}      - general goal
   879   @{lemma prop1 ... propN by meth1 meth2} - general goal
   880   @{lemma (open) ...}                     - open derivation
   881 
   882 
   883 *** System ***
   884 
   885 * The Isabelle "emacs" tool provides a specific interface to invoke
   886 Proof General / Emacs, with more explicit failure if that is not
   887 installed (the old isabelle-interface script silently falls back on
   888 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   889 installation location of the Proof General distribution.
   890 
   891 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   892 the Isabelle process into a JVM/Scala application.  See
   893 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   894 process wrapper has been discontinued.)
   895 
   896 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   897 
   898 * Various status messages (with exact source position information) are
   899 emitted, if proper markup print mode is enabled.  This allows
   900 user-interface components to provide detailed feedback on internal
   901 prover operations.
   902 
   903 
   904 
   905 New in Isabelle2008 (June 2008)
   906 -------------------------------
   907 
   908 *** General ***
   909 
   910 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   911 and updated, with formally checked references as hyperlinks.
   912 
   913 * Theory loader: use_thy (and similar operations) no longer set the
   914 implicit ML context, which was occasionally hard to predict and in
   915 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   916 provides a proper context already.
   917 
   918 * Theory loader: old-style ML proof scripts being *attached* to a thy
   919 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   920 'use' within a theory file will do the job.
   921 
   922 * Name space merge now observes canonical order, i.e. the second space
   923 is inserted into the first one, while existing entries in the first
   924 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   925 swap theory imports.
   926 
   927 * Syntax: symbol \<chi> is now considered a letter.  Potential
   928 INCOMPATIBILITY in identifier syntax etc.
   929 
   930 * Outer syntax: string tokens no longer admit escaped white space,
   931 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   932 white space without escapes.
   933 
   934 * Outer syntax: string tokens may contain arbitrary character codes
   935 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   936 "foo_bar".
   937 
   938 
   939 *** Pure ***
   940 
   941 * Context-dependent token translations.  Default setup reverts locally
   942 fixed variables, and adds hilite markup for undeclared frees.
   943 
   944 * Unused theorems can be found using the new command 'unused_thms'.
   945 There are three ways of invoking it:
   946 
   947 (1) unused_thms
   948      Only finds unused theorems in the current theory.
   949 
   950 (2) unused_thms thy_1 ... thy_n -
   951      Finds unused theorems in the current theory and all of its ancestors,
   952      excluding the theories thy_1 ... thy_n and all of their ancestors.
   953 
   954 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   955      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   956      their ancestors, excluding the theories thy_1 ... thy_n and all of
   957      their ancestors.
   958 
   959 In order to increase the readability of the list produced by
   960 unused_thms, theorems that have been created by a particular instance
   961 of a theory command such as 'inductive' or 'function' are considered
   962 to belong to the same "group", meaning that if at least one theorem in
   963 this group is used, the other theorems in the same group are no longer
   964 reported as unused.  Moreover, if all theorems in the group are
   965 unused, only one theorem in the group is displayed.
   966 
   967 Note that proof objects have to be switched on in order for
   968 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   969 usually the case when using Proof General with the default settings).
   970 
   971 * Authentic naming of facts disallows ad-hoc overwriting of previous
   972 theorems within the same name space.  INCOMPATIBILITY, need to remove
   973 duplicate fact bindings, or even accidental fact duplications.  Note
   974 that tools may maintain dynamically scoped facts systematically, using
   975 PureThy.add_thms_dynamic.
   976 
   977 * Command 'hide' now allows to hide from "fact" name space as well.
   978 
   979 * Eliminated destructive theorem database, simpset, claset, and
   980 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   981 update of theories within ML code.
   982 
   983 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   984 INCOMPATIBILITY, object-logics depending on former Pure require
   985 additional setup PureThy.old_appl_syntax_setup; object-logics
   986 depending on former CPure need to refer to Pure.
   987 
   988 * Commands 'use' and 'ML' are now purely functional, operating on
   989 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
   990 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
   991 INCOMPATIBILITY.
   992 
   993 * Command 'setup': discontinued implicit version with ML reference.
   994 
   995 * Instantiation target allows for simultaneous specification of class
   996 instance operations together with an instantiation proof.
   997 Type-checking phase allows to refer to class operations uniformly.
   998 See src/HOL/Complex/Complex.thy for an Isar example and
   999 src/HOL/Library/Eval.thy for an ML example.
  1000 
  1001 * Indexing of literal facts: be more serious about including only
  1002 facts from the visible specification/proof context, but not the
  1003 background context (locale etc.).  Affects `prop` notation and method
  1004 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1005 situations.
  1006 
  1007 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1008 "(open)" option, which used to expose internal bound variables to the
  1009 proof text.
  1010 
  1011 * Isar statements: removed obsolete case "rule_context".
  1012 INCOMPATIBILITY, better use explicit fixes/assumes.
  1013 
  1014 * Locale proofs: default proof step now includes 'unfold_locales';
  1015 hence 'proof' without argument may be used to unfold locale
  1016 predicates.
  1017 
  1018 
  1019 *** Document preparation ***
  1020 
  1021 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1022 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1023 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1024 spot); renamed link color from "darkblue" to "linkcolor" (default
  1025 value unchanged, can be redefined via \definecolor); no longer sets
  1026 "a4paper" option (unnecessary or even intrusive).
  1027 
  1028 * Antiquotation @{lemma A method} proves proposition A by the given
  1029 method (either a method name or a method name plus (optional) method
  1030 arguments in parentheses) and prints A just like @{prop A}.
  1031 
  1032 
  1033 *** HOL ***
  1034 
  1035 * New primrec package.  Specification syntax conforms in style to
  1036 definition/function/....  No separate induction rule is provided.  The
  1037 "primrec" command distinguishes old-style and new-style specifications
  1038 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1039 When adjusting theories, beware: constants stemming from new-style
  1040 primrec specifications have authentic syntax.
  1041 
  1042 * Metis prover is now an order of magnitude faster, and also works
  1043 with multithreading.
  1044 
  1045 * Metis: the maximum number of clauses that can be produced from a
  1046 theorem is now given by the attribute max_clauses.  Theorems that
  1047 exceed this number are ignored, with a warning printed.
  1048 
  1049 * Sledgehammer no longer produces structured proofs by default. To
  1050 enable, declare [[sledgehammer_full = true]].  Attributes
  1051 reconstruction_modulus, reconstruction_sorts renamed
  1052 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1053 
  1054 * Method "induct_scheme" derives user-specified induction rules
  1055 from well-founded induction and completeness of patterns. This factors
  1056 out some operations that are done internally by the function package
  1057 and makes them available separately.  See
  1058 src/HOL/ex/Induction_Scheme.thy for examples.
  1059 
  1060 * More flexible generation of measure functions for termination
  1061 proofs: Measure functions can be declared by proving a rule of the
  1062 form "is_measure f" and giving it the [measure_function] attribute.
  1063 The "is_measure" predicate is logically meaningless (always true), and
  1064 just guides the heuristic.  To find suitable measure functions, the
  1065 termination prover sets up the goal "is_measure ?f" of the appropriate
  1066 type and generates all solutions by prolog-style backwards proof using
  1067 the declared rules.
  1068 
  1069 This setup also deals with rules like 
  1070 
  1071   "is_measure f ==> is_measure (list_size f)"
  1072 
  1073 which accommodates nested datatypes that recurse through lists.
  1074 Similar rules are predeclared for products and option types.
  1075 
  1076 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1077 
  1078   INCOMPATIBILITIES:
  1079 
  1080   - Definitions of overloaded constants on sets have to be replaced by
  1081     definitions on => and bool.
  1082 
  1083   - Some definitions of overloaded operators on sets can now be proved
  1084     using the definitions of the operators on => and bool.  Therefore,
  1085     the following theorems have been renamed:
  1086 
  1087       subset_def   -> subset_eq
  1088       psubset_def  -> psubset_eq
  1089       set_diff_def -> set_diff_eq
  1090       Compl_def    -> Compl_eq
  1091       Sup_set_def  -> Sup_set_eq
  1092       Inf_set_def  -> Inf_set_eq
  1093       sup_set_def  -> sup_set_eq
  1094       inf_set_def  -> inf_set_eq
  1095 
  1096   - Due to the incompleteness of the HO unification algorithm, some
  1097     rules such as subst may require manual instantiation, if some of
  1098     the unknowns in the rule is a set.
  1099 
  1100   - Higher order unification and forward proofs:
  1101     The proof pattern
  1102 
  1103       have "P (S::'a set)" <...>
  1104       then have "EX S. P S" ..
  1105 
  1106     no longer works (due to the incompleteness of the HO unification
  1107     algorithm) and must be replaced by the pattern
  1108 
  1109       have "EX S. P S"
  1110       proof
  1111         show "P S" <...>
  1112       qed
  1113 
  1114   - Calculational reasoning with subst (or similar rules):
  1115     The proof pattern
  1116 
  1117       have "P (S::'a set)" <...>
  1118       also have "S = T" <...>
  1119       finally have "P T" .
  1120 
  1121     no longer works (for similar reasons as the previous example) and
  1122     must be replaced by something like
  1123 
  1124       have "P (S::'a set)" <...>
  1125       moreover have "S = T" <...>
  1126       ultimately have "P T" by simp
  1127 
  1128   - Tactics or packages written in ML code:
  1129     Code performing pattern matching on types via
  1130 
  1131       Type ("set", [T]) => ...
  1132 
  1133     must be rewritten. Moreover, functions like strip_type or
  1134     binder_types no longer return the right value when applied to a
  1135     type of the form
  1136 
  1137       T1 => ... => Tn => U => bool
  1138 
  1139     rather than
  1140 
  1141       T1 => ... => Tn => U set
  1142 
  1143 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1144 Wellfounded_Relations to theory Wellfounded.
  1145 
  1146 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1147 
  1148 * Class finite no longer treats UNIV as class parameter.  Use class
  1149 enum from theory Library/Enum instead to achieve a similar effect.
  1150 INCOMPATIBILITY.
  1151 
  1152 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1153 and "Cons".  INCOMPATIBILITY.
  1154 
  1155 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1156 Potential INCOMPATIBILITY.
  1157 
  1158 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1159 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1160 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1161 
  1162 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1163 the same name in theory Orderings:
  1164 
  1165   less_trans
  1166   less_linear
  1167   le_imp_less_or_eq
  1168   le_less_trans
  1169   less_le_trans
  1170   less_not_sym
  1171   less_asym
  1172 
  1173 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1174 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1175 and different variable names.
  1176 
  1177 * Library/Option_ord.thy: Canonical order on option type.
  1178 
  1179 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1180 finite maps.
  1181 
  1182 * Library/Countable.thy: Type class for countable types.
  1183 
  1184 * Theory Int: The representation of numerals has changed.  The infix
  1185 operator BIT and the bit datatype with constructors B0 and B1 have
  1186 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1187 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1188 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1189 accordingly.
  1190 
  1191 * Theory Nat: definition of <= and < on natural numbers no longer
  1192 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1193 le_def and less_def have disappeared.  Consider lemmas not_less
  1194 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1195 
  1196 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1197 (whose purpose mainly is for various fold_set functionals) have been
  1198 abandoned in favor of the existing algebraic classes
  1199 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1200 lower_semilattice (resp. upper_semilattice) and linorder.
  1201 INCOMPATIBILITY.
  1202 
  1203 * Theory Transitive_Closure: induct and cases rules now declare proper
  1204 case_names ("base" and "step").  INCOMPATIBILITY.
  1205 
  1206 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1207 lattices.  The form set-specific version is available as
  1208 Inductive.lfp_ordinal_induct_set.
  1209 
  1210 * Renamed theorems "power.simps" to "power_int.simps".
  1211 INCOMPATIBILITY.
  1212 
  1213 * Class semiring_div provides basic abstract properties of semirings
  1214 with division and modulo operations.  Subsumes former class dvd_mod.
  1215 
  1216 * Merged theories IntDef, Numeral and IntArith into unified theory
  1217 Int.  INCOMPATIBILITY.
  1218 
  1219 * Theory Library/Code_Index: type "index" now represents natural
  1220 numbers rather than integers.  INCOMPATIBILITY.
  1221 
  1222 * New class "uminus" with operation "uminus" (split of from class
  1223 "minus" which now only has operation "minus", binary).
  1224 INCOMPATIBILITY.
  1225 
  1226 * Constants "card", "internal_split", "option_map" now with authentic
  1227 syntax.  INCOMPATIBILITY.
  1228 
  1229 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1230 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1231 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1232 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1233 Sup_set_def, le_def, less_def, option_map_def now with object
  1234 equality.  INCOMPATIBILITY.
  1235 
  1236 * Records. Removed K_record, and replaced it by pure lambda term
  1237 %x. c. The simplifier setup is now more robust against eta expansion.
  1238 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1239 
  1240 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1241 
  1242 * Library/ListVector: new theory of arithmetic vector operations.
  1243 
  1244 * Library/Order_Relation: new theory of various orderings as sets of
  1245 pairs.  Defines preorders, partial orders, linear orders and
  1246 well-orders on sets and on types.
  1247 
  1248 
  1249 *** ZF ***
  1250 
  1251 * Renamed some theories to allow to loading both ZF and HOL in the
  1252 same session:
  1253 
  1254   Datatype  -> Datatype_ZF
  1255   Inductive -> Inductive_ZF
  1256   Int       -> Int_ZF
  1257   IntDiv    -> IntDiv_ZF
  1258   Nat       -> Nat_ZF
  1259   List      -> List_ZF
  1260   Main      -> Main_ZF
  1261 
  1262 INCOMPATIBILITY: ZF theories that import individual theories below
  1263 Main might need to be adapted.  Regular theory Main is still
  1264 available, as trivial extension of Main_ZF.
  1265 
  1266 
  1267 *** ML ***
  1268 
  1269 * ML within Isar: antiquotation @{const name} or @{const
  1270 name(typargs)} produces statically-checked Const term.
  1271 
  1272 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1273 (of the same name).  Removed obsolete print command.
  1274 
  1275 * Removed obsolete "use_legacy_bindings" function.
  1276 
  1277 * The ``print mode'' is now a thread-local value derived from a global
  1278 template (the former print_mode reference), thus access becomes
  1279 non-critical.  The global print_mode reference is for session
  1280 management only; user-code should use print_mode_value,
  1281 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1282 
  1283 * Functions system/system_out provide a robust way to invoke external
  1284 shell commands, with propagation of interrupts (requires Poly/ML
  1285 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1286 
  1287 
  1288 *** System ***
  1289 
  1290 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1291 in accordance with Proof General 3.7, which prefers GNU emacs.
  1292 
  1293 * isatool tty runs Isabelle process with plain tty interaction;
  1294 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1295 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1296 
  1297 * isatool browser now works with Cygwin as well, using general
  1298 "javapath" function defined in Isabelle process environment.
  1299 
  1300 * YXML notation provides a simple and efficient alternative to
  1301 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1302 isatool yxml as described in the Isabelle system manual.
  1303 
  1304 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1305 provides general wrapper for managing an Isabelle process in a robust
  1306 fashion, with ``cooked'' output from stdin/stderr.
  1307 
  1308 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1309 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1310 
  1311 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1312 way of changing the user's settings is via
  1313 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1314 script.
  1315 
  1316 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1317 cores of the underlying machine, which is a good starting point for
  1318 optimal performance tuning.  The corresponding usedir option -M allows
  1319 "max" as an alias for "0".  WARNING: does not work on certain versions
  1320 of Mac OS (with Poly/ML 5.1).
  1321 
  1322 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1323 adverse effect of Isabelle flooding interactive front-ends (notably
  1324 ProofGeneral / XEmacs).
  1325 
  1326 
  1327 
  1328 New in Isabelle2007 (November 2007)
  1329 -----------------------------------
  1330 
  1331 *** General ***
  1332 
  1333 * More uniform information about legacy features, notably a
  1334 warning/error of "Legacy feature: ...", depending on the state of the
  1335 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1336 legacy features will disappear eventually.
  1337 
  1338 * Theory syntax: the header format ``theory A = B + C:'' has been
  1339 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1340 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1341 
  1342 * Theory syntax: the old non-Isar theory file format has been
  1343 discontinued altogether.  Note that ML proof scripts may still be used
  1344 with Isar theories; migration is usually quite simple with the ML
  1345 function use_legacy_bindings.  INCOMPATIBILITY.
  1346 
  1347 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1348 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1349 quotes.
  1350 
  1351 * Theory loader: be more serious about observing the static theory
  1352 header specifications (including optional directories), but not the
  1353 accidental file locations of previously successful loads.  The strict
  1354 update policy of former update_thy is now already performed by
  1355 use_thy, so the former has been removed; use_thys updates several
  1356 theories simultaneously, just as 'imports' within a theory header
  1357 specification, but without merging the results.  Potential
  1358 INCOMPATIBILITY: may need to refine theory headers and commands
  1359 ROOT.ML which depend on load order.
  1360 
  1361 * Theory loader: optional support for content-based file
  1362 identification, instead of the traditional scheme of full physical
  1363 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1364 (cf. the system manual).  The new scheme allows to work with
  1365 non-finished theories in persistent session images, such that source
  1366 files may be moved later on without requiring reloads.
  1367 
  1368 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1369 file (with the same base name as the theory) are considered a legacy
  1370 feature, which will disappear eventually. Even now, the theory loader
  1371 no longer maintains dependencies on such files.
  1372 
  1373 * Syntax: the scope for resolving ambiguities via type-inference is
  1374 now limited to individual terms, instead of whole simultaneous
  1375 specifications as before. This greatly reduces the complexity of the
  1376 syntax module and improves flexibility by separating parsing and
  1377 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1378 'fixes' etc.) are required in rare situations.
  1379 
  1380 * Syntax: constants introduced by new-style packages ('definition',
  1381 'abbreviation' etc.) are passed through the syntax module in
  1382 ``authentic mode''. This means that associated mixfix annotations
  1383 really stick to such constants, independently of potential name space
  1384 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1385 trees are represented slightly differently, may need to adapt syntax
  1386 translations accordingly. Use CONST marker in 'translations' and
  1387 @{const_syntax} antiquotation in 'parse_translation' etc.
  1388 
  1389 * Legacy goal package: reduced interface to the bare minimum required
  1390 to keep existing proof scripts running.  Most other user-level
  1391 functions are now part of the OldGoals structure, which is *not* open
  1392 by default (consider isatool expandshort before open OldGoals).
  1393 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1394 these tend to cause confusion about the actual goal (!) context being
  1395 used here, which is not necessarily the same as the_context().
  1396 
  1397 * Command 'find_theorems': supports "*" wild-card in "name:"
  1398 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1399 support a specific search form (see ProofGeneral/CHANGES).
  1400 
  1401 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1402 by default, which means that "prems" (and also "fixed variables") are
  1403 suppressed from proof state output.  Note that the ProofGeneral
  1404 settings mechanism allows to change and save options persistently, but
  1405 older versions of Isabelle will fail to start up if a negative prems
  1406 limit is imposed.
  1407 
  1408 * Local theory targets may be specified by non-nested blocks of
  1409 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1410 contain definitions, theorems etc., including any derived mechanism
  1411 that has been implemented on top of these primitives.  This concept
  1412 generalizes the existing ``theorem (in ...)'' towards more versatility
  1413 and scalability.
  1414 
  1415 * Proof General interface: proper undo of final 'end' command;
  1416 discontinued Isabelle/classic mode (ML proof scripts).
  1417 
  1418 
  1419 *** Document preparation ***
  1420 
  1421 * Added antiquotation @{theory name} which prints the given name,
  1422 after checking that it refers to a valid ancestor theory in the
  1423 current context.
  1424 
  1425 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1426 check the given source text as ML type/structure, printing verbatim.
  1427 
  1428 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1429 "c args == rhs" given in the current context.  (Any number of
  1430 arguments may be given on the LHS.)
  1431 
  1432 
  1433 *** Pure ***
  1434 
  1435 * The 'class' package offers a combination of axclass and locale to
  1436 achieve Haskell-like type classes in Isabelle.  Definitions and
  1437 theorems within a class context produce both relative results (with
  1438 implicit parameters according to the locale context), and polymorphic
  1439 constants with qualified polymorphism (according to the class
  1440 context).  Within the body context of a 'class' target, a separate
  1441 syntax layer ("user space type system") takes care of converting
  1442 between global polymorphic consts and internal locale representation.
  1443 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1444 "isatool doc classes" provides a tutorial.
  1445 
  1446 * Generic code generator framework allows to generate executable
  1447 code for ML and Haskell (including Isabelle classes).  A short usage
  1448 sketch:
  1449 
  1450     internal compilation:
  1451         export_code <list of constants (term syntax)> in SML
  1452     writing SML code to a file:
  1453         export_code <list of constants (term syntax)> in SML <filename>
  1454     writing OCaml code to a file:
  1455         export_code <list of constants (term syntax)> in OCaml <filename>
  1456     writing Haskell code to a bunch of files:
  1457         export_code <list of constants (term syntax)> in Haskell <filename>
  1458 
  1459     evaluating closed propositions to True/False using code generation:
  1460         method ``eval''
  1461 
  1462 Reasonable default setup of framework in HOL.
  1463 
  1464 Theorem attributs for selecting and transforming function equations theorems:
  1465 
  1466     [code fun]:        select a theorem as function equation for a specific constant
  1467     [code fun del]:    deselect a theorem as function equation for a specific constant
  1468     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1469     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1470 
  1471 User-defined serializations (target in {SML, OCaml, Haskell}):
  1472 
  1473     code_const <and-list of constants (term syntax)>
  1474       {(target) <and-list of const target syntax>}+
  1475 
  1476     code_type <and-list of type constructors>
  1477       {(target) <and-list of type target syntax>}+
  1478 
  1479     code_instance <and-list of instances>
  1480       {(target)}+
  1481         where instance ::= <type constructor> :: <class>
  1482 
  1483     code_class <and_list of classes>
  1484       {(target) <and-list of class target syntax>}+
  1485         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1486 
  1487 code_instance and code_class only are effective to target Haskell.
  1488 
  1489 For example usage see src/HOL/ex/Codegenerator.thy and
  1490 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1491 generation from Isabelle/HOL theories is available via "isatool doc
  1492 codegen".
  1493 
  1494 * Code generator: consts in 'consts_code' Isar commands are now
  1495 referred to by usual term syntax (including optional type
  1496 annotations).
  1497 
  1498 * Command 'no_translations' removes translation rules from theory
  1499 syntax.
  1500 
  1501 * Overloaded definitions are now actually checked for acyclic
  1502 dependencies.  The overloading scheme is slightly more general than
  1503 that of Haskell98, although Isabelle does not demand an exact
  1504 correspondence to type class and instance declarations.
  1505 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1506 exotic versions of overloading -- at the discretion of the user!
  1507 
  1508 Polymorphic constants are represented via type arguments, i.e. the
  1509 instantiation that matches an instance against the most general
  1510 declaration given in the signature.  For example, with the declaration
  1511 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1512 as c(nat).  Overloading is essentially simultaneous structural
  1513 recursion over such type arguments.  Incomplete specification patterns
  1514 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1515 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1516 Command 'print_theory' outputs the normalized system of recursive
  1517 equations, see section "definitions".
  1518 
  1519 * Configuration options are maintained within the theory or proof
  1520 context (with name and type bool/int/string), providing a very simple
  1521 interface to a poor-man's version of general context data.  Tools may
  1522 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1523 these values using Config.get etc.  Users may change options via an
  1524 associated attribute of the same name.  This form of context
  1525 declaration works particularly well with commands 'declare' or
  1526 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1527 very easy to avoid global references, which would not observe Isar
  1528 toplevel undo/redo and fail to work with multithreading.
  1529 
  1530 Various global ML references of Pure and HOL have been turned into
  1531 configuration options:
  1532 
  1533   Unify.search_bound		unify_search_bound
  1534   Unify.trace_bound		unify_trace_bound
  1535   Unify.trace_simp		unify_trace_simp
  1536   Unify.trace_types		unify_trace_types
  1537   Simplifier.simp_depth_limit	simp_depth_limit
  1538   Blast.depth_limit		blast_depth_limit
  1539   DatatypeProp.dtK		datatype_distinctness_limit
  1540   fast_arith_neq_limit  	fast_arith_neq_limit
  1541   fast_arith_split_limit	fast_arith_split_limit
  1542 
  1543 * Named collections of theorems may be easily installed as context
  1544 data using the functor NamedThmsFun (see also
  1545 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1546 attributes; there is also a toplevel print command.  This facility is
  1547 just a common case of general context data, which is the preferred way
  1548 for anything more complex than just a list of facts in canonical
  1549 order.
  1550 
  1551 * Isar: command 'declaration' augments a local theory by generic
  1552 declaration functions written in ML.  This enables arbitrary content
  1553 being added to the context, depending on a morphism that tells the
  1554 difference of the original declaration context wrt. the application
  1555 context encountered later on.
  1556 
  1557 * Isar: proper interfaces for simplification procedures.  Command
  1558 'simproc_setup' declares named simprocs (with match patterns, and body
  1559 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1560 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1561 
  1562 * Isar: an extra pair of brackets around attribute declarations
  1563 abbreviates a theorem reference involving an internal dummy fact,
  1564 which will be ignored later --- only the effect of the attribute on
  1565 the background context will persist.  This form of in-place
  1566 declarations is particularly useful with commands like 'declare' and
  1567 'using', for example ``have A using [[simproc a]] by simp''.
  1568 
  1569 * Isar: method "assumption" (and implicit closing of subproofs) now
  1570 takes simple non-atomic goal assumptions into account: after applying
  1571 an assumption as a rule the resulting subgoals are solved by atomic
  1572 assumption steps.  This is particularly useful to finish 'obtain'
  1573 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1574 without referring to the original premise "!!x. P x ==> thesis" in the
  1575 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1576 more permissive.
  1577 
  1578 * Isar: implicit use of prems from the Isar proof context is
  1579 considered a legacy feature.  Common applications like ``have A .''
  1580 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1581 referencing facts explicitly here improves readability and
  1582 maintainability of proof texts.
  1583 
  1584 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1585 the obtained context from the course of reasoning!  For example:
  1586 
  1587   assume "EX x y. A x & B y"   -- "any previous fact"
  1588   then guess x and y by clarify
  1589 
  1590 This technique is potentially adventurous, depending on the facts and
  1591 proof tools being involved here.
  1592 
  1593 * Isar: known facts from the proof context may be specified as literal
  1594 propositions, using ASCII back-quote syntax.  This works wherever
  1595 named facts used to be allowed so far, in proof commands, proof
  1596 methods, attributes etc.  Literal facts are retrieved from the context
  1597 according to unification of type and term parameters.  For example,
  1598 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1599 theorems in the current context, then these are valid literal facts:
  1600 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1601 
  1602 There is also a proof method "fact" which does the same composition
  1603 for explicit goal states, e.g. the following proof texts coincide with
  1604 certain special cases of literal facts:
  1605 
  1606   have "A" by fact                 ==  note `A`
  1607   have "A ==> B" by fact           ==  note `A ==> B`
  1608   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1609   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1610 
  1611 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1612 outer syntax.  Thus symbolic identifiers may be used without
  1613 additional white space in declarations like this: ``assume *: A''.
  1614 
  1615 * Isar: 'print_facts' prints all local facts of the current context,
  1616 both named and unnamed ones.
  1617 
  1618 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1619 
  1620   def x == "t" and y == "u"
  1621 
  1622 * Isar: added command 'unfolding', which is structurally similar to
  1623 'using', but affects both the goal state and facts by unfolding given
  1624 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1625 'unfolded' attribute may be replaced by first-class proof text.
  1626 
  1627 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1628 and command 'unfolding' now all support object-level equalities
  1629 (potentially conditional).  The underlying notion of rewrite rule is
  1630 analogous to the 'rule_format' attribute, but *not* that of the
  1631 Simplifier (which is usually more generous).
  1632 
  1633 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1634 premises of a theorem by n. Useful in conjunction with drule.
  1635 
  1636 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1637 method expression within a sandbox consisting of the first N
  1638 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1639 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1640 simplifies all new goals that emerge from applying rule foo to the
  1641 originally first one.
  1642 
  1643 * Isar: schematic goals are no longer restricted to higher-order
  1644 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1645 expected.
  1646 
  1647 * Isar: the conclusion of a long theorem statement is now either
  1648 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1649 (essentially a disjunction of cases with local parameters and
  1650 assumptions).  The latter allows to express general elimination rules
  1651 adequately; in this notation common elimination rules look like this:
  1652 
  1653   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1654     assumes "EX x. P x"
  1655     obtains x where "P x"
  1656 
  1657   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1658     assumes "A & B"
  1659     obtains A and B
  1660 
  1661   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1662     assumes "A | B"
  1663     obtains
  1664       A
  1665     | B
  1666 
  1667 The subsequent classical rules even refer to the formal "thesis"
  1668 explicitly:
  1669 
  1670   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1671     obtains "~ thesis"
  1672 
  1673   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1674     obtains "thesis ==> something"
  1675 
  1676 The actual proof of an 'obtains' statement is analogous to that of the
  1677 Isar proof element 'obtain', only that there may be several cases.
  1678 Optional case names may be specified in parentheses; these will be
  1679 available both in the present proof and as annotations in the
  1680 resulting rule, for later use with the 'cases' method (cf. attribute
  1681 case_names).
  1682 
  1683 * Isar: the assumptions of a long theorem statement are available as
  1684 "assms" fact in the proof context.  This is more appropriate than the
  1685 (historical) "prems", which refers to all assumptions of the current
  1686 context, including those from the target locale, proof body etc.
  1687 
  1688 * Isar: 'print_statement' prints theorems from the current theory or
  1689 proof context in long statement form, according to the syntax of a
  1690 top-level lemma.
  1691 
  1692 * Isar: 'obtain' takes an optional case name for the local context
  1693 introduction rule (default "that").
  1694 
  1695 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1696 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1697 to occur.
  1698 
  1699 * Pure: syntax "CONST name" produces a fully internalized constant
  1700 according to the current context.  This is particularly useful for
  1701 syntax translations that should refer to internal constant
  1702 representations independently of name spaces.
  1703 
  1704 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1705 instead of "FOO ". This allows multiple binder declarations to coexist
  1706 in the same context.  INCOMPATIBILITY.
  1707 
  1708 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1709 primitive that also works in a locale context (both for constants and
  1710 fixed variables). Type declaration and internal syntactic representation
  1711 of given constants retrieved from the context. Likewise, the
  1712 'no_notation' command allows to remove given syntax annotations from the
  1713 current context.
  1714 
  1715 * Isar/locales: new derived specification elements 'axiomatization',
  1716 'definition', 'abbreviation', which support type-inference, admit
  1717 object-level specifications (equality, equivalence).  See also the
  1718 isar-ref manual.  Examples:
  1719 
  1720   axiomatization
  1721     eq  (infix "===" 50) where
  1722     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1723 
  1724   definition "f x y = x + y + 1"
  1725   definition g where "g x = f x x"
  1726 
  1727   abbreviation
  1728     neq  (infix "=!=" 50) where
  1729     "x =!= y == ~ (x === y)"
  1730 
  1731 These specifications may be also used in a locale context.  Then the
  1732 constants being introduced depend on certain fixed parameters, and the
  1733 constant name is qualified by the locale base name.  An internal
  1734 abbreviation takes care for convenient input and output, making the
  1735 parameters implicit and using the original short name.  See also
  1736 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1737 entities from a monomorphic theory.
  1738 
  1739 Presently, abbreviations are only available 'in' a target locale, but
  1740 not inherited by general import expressions.  Also note that
  1741 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1742 'translations' in common applications.  The "no_abbrevs" print mode
  1743 prevents folding of abbreviations in term output.
  1744 
  1745 Concrete syntax is attached to specified constants in internal form,
  1746 independently of name spaces.  The parse tree representation is
  1747 slightly different -- use 'notation' instead of raw 'syntax', and
  1748 'translations' with explicit "CONST" markup to accommodate this.
  1749 
  1750 * Pure/Isar: unified syntax for new-style specification mechanisms
  1751 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1752 full type inference and dummy patterns ("_").  For example:
  1753 
  1754   definition "K x _ = x"
  1755 
  1756   inductive conj for A B
  1757   where "A ==> B ==> conj A B"
  1758 
  1759 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1760 the current context.  Print mode "no_abbrevs" prevents inversion of
  1761 abbreviations on output.
  1762 
  1763 * Isar/locales: improved parameter handling: use of locales "var" and
  1764 "struct" no longer necessary; - parameter renamings are no longer
  1765 required to be injective.  For example, this allows to define
  1766 endomorphisms as locale endom = homom mult mult h.
  1767 
  1768 * Isar/locales: changed the way locales with predicates are defined.
  1769 Instead of accumulating the specification, the imported expression is
  1770 now an interpretation.  INCOMPATIBILITY: different normal form of
  1771 locale expressions.  In particular, in interpretations of locales with
  1772 predicates, goals repesenting already interpreted fragments are not
  1773 removed automatically.  Use methods `intro_locales' and
  1774 `unfold_locales'; see below.
  1775 
  1776 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1777 provide backward reasoning on locales predicates.  The methods are
  1778 aware of interpretations and discharge corresponding goals.
  1779 `intro_locales' is less aggressive then `unfold_locales' and does not
  1780 unfold predicates to assumptions.
  1781 
  1782 * Isar/locales: the order in which locale fragments are accumulated
  1783 has changed.  This enables to override declarations from fragments due
  1784 to interpretations -- for example, unwanted simp rules.
  1785 
  1786 * Isar/locales: interpretation in theories and proof contexts has been
  1787 extended.  One may now specify (and prove) equations, which are
  1788 unfolded in interpreted theorems.  This is useful for replacing
  1789 defined concepts (constants depending on locale parameters) by
  1790 concepts already existing in the target context.  Example:
  1791 
  1792   interpretation partial_order ["op <= :: [int, int] => bool"]
  1793     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1794 
  1795 Typically, the constant `partial_order.less' is created by a
  1796 definition specification element in the context of locale
  1797 partial_order.
  1798 
  1799 * Method "induct": improved internal context management to support
  1800 local fixes and defines on-the-fly. Thus explicit meta-level
  1801 connectives !!  and ==> are rarely required anymore in inductive goals
  1802 (using object-logic connectives for this purpose has been long
  1803 obsolete anyway). Common proof patterns are explained in
  1804 src/HOL/Induct/Common_Patterns.thy, see also
  1805 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1806 examples.
  1807 
  1808 * Method "induct": improved handling of simultaneous goals. Instead of
  1809 introducing object-level conjunction, the statement is now split into
  1810 several conclusions, while the corresponding symbolic cases are nested
  1811 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1812 see src/HOL/Induct/Common_Patterns.thy, for example.
  1813 
  1814 * Method "induct": mutual induction rules are now specified as a list
  1815 of rule sharing the same induction cases. HOL packages usually provide
  1816 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1817 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1818 mutual induction rules differently, i.e. like this:
  1819 
  1820   (induct rule: foo_bar.inducts)
  1821   (induct set: foo bar)
  1822   (induct pred: foo bar)
  1823   (induct type: foo bar)
  1824 
  1825 The ML function ProjectRule.projections turns old-style rules into the
  1826 new format.
  1827 
  1828 * Method "coinduct": dual of induction, see
  1829 src/HOL/Library/Coinductive_List.thy for various examples.
  1830 
  1831 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1832 considered a legacy feature.
  1833 
  1834 * Attribute "symmetric" produces result with standardized schematic
  1835 variables (index 0).  Potential INCOMPATIBILITY.
  1836 
  1837 * Simplifier: by default the simplifier trace only shows top level
  1838 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1839 default. Thus there is less danger of being flooded by the trace. The
  1840 trace indicates where parts have been suppressed.
  1841   
  1842 * Provers/classical: removed obsolete classical version of elim_format
  1843 attribute; classical elim/dest rules are now treated uniformly when
  1844 manipulating the claset.
  1845 
  1846 * Provers/classical: stricter checks to ensure that supplied intro,
  1847 dest and elim rules are well-formed; dest and elim rules must have at
  1848 least one premise.
  1849 
  1850 * Provers/classical: attributes dest/elim/intro take an optional
  1851 weight argument for the rule (just as the Pure versions).  Weights are
  1852 ignored by automated tools, but determine the search order of single
  1853 rule steps.
  1854 
  1855 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1856 where the body does not mention the bound variable.  Note that dummy
  1857 patterns implicitly depend on their context of bounds, which makes
  1858 "{_. _}" match any set comprehension as expected.  Potential
  1859 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1860 constant "_idtdummy" in the binding position.
  1861 
  1862 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1863 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1864 for example "A -> B" => "Pi A (%_. B)".
  1865 
  1866 * Pure: 'class_deps' command visualizes the subclass relation, using
  1867 the graph browser tool.
  1868 
  1869 * Pure: 'print_theory' now suppresses certain internal declarations by
  1870 default; use '!' option for full details.
  1871 
  1872 
  1873 *** HOL ***
  1874 
  1875 * Method "metis" proves goals by applying the Metis general-purpose
  1876 resolution prover (see also http://gilith.com/software/metis/).
  1877 Examples are in the directory MetisExamples.  WARNING: the
  1878 Isabelle/HOL-Metis integration does not yet work properly with
  1879 multi-threading.
  1880   
  1881 * Command 'sledgehammer' invokes external automatic theorem provers as
  1882 background processes.  It generates calls to the "metis" method if
  1883 successful. These can be pasted into the proof.  Users do not have to
  1884 wait for the automatic provers to return.  WARNING: does not really
  1885 work with multi-threading.
  1886 
  1887 * New "auto_quickcheck" feature tests outermost goal statements for
  1888 potential counter-examples.  Controlled by ML references
  1889 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1890 5000 milliseconds).  Fails silently if statements is outside of
  1891 executable fragment, or any other codgenerator problem occurs.
  1892 
  1893 * New constant "undefined" with axiom "undefined x = undefined".
  1894 
  1895 * Added class "HOL.eq", allowing for code generation with polymorphic
  1896 equality.
  1897 
  1898 * Some renaming of class constants due to canonical name prefixing in
  1899 the new 'class' package:
  1900 
  1901     HOL.abs ~> HOL.abs_class.abs
  1902     HOL.divide ~> HOL.divide_class.divide
  1903     0 ~> HOL.zero_class.zero
  1904     1 ~> HOL.one_class.one
  1905     op + ~> HOL.plus_class.plus
  1906     op - ~> HOL.minus_class.minus
  1907     uminus ~> HOL.minus_class.uminus
  1908     op * ~> HOL.times_class.times
  1909     op < ~> HOL.ord_class.less
  1910     op <= > HOL.ord_class.less_eq
  1911     Nat.power ~> Power.power_class.power
  1912     Nat.size ~> Nat.size_class.size
  1913     Numeral.number_of ~> Numeral.number_class.number_of
  1914     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1915     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1916     Orderings.min ~> Orderings.ord_class.min
  1917     Orderings.max ~> Orderings.ord_class.max
  1918     Divides.op div ~> Divides.div_class.div
  1919     Divides.op mod ~> Divides.div_class.mod
  1920     Divides.op dvd ~> Divides.div_class.dvd
  1921 
  1922 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1923 
  1924 a) User-defined constants using any of the names "plus", "minus",
  1925 "times", "less" or "less_eq". The standard syntax translations for
  1926 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1927 names.
  1928 
  1929 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1930 INCOMPATIBILITY: use more specific names.
  1931 
  1932 c) Permutative equations (e.g. "a + b = b + a")
  1933 Since the change of names also changes the order of terms, permutative
  1934 rewrite rules may get applied in a different order. Experience shows
  1935 that this is rarely the case (only two adaptions in the whole Isabelle
  1936 distribution).  INCOMPATIBILITY: rewrite proofs
  1937 
  1938 d) ML code directly refering to constant names
  1939 This in general only affects hand-written proof tactics, simprocs and
  1940 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1941 Consider using @{const_name} antiquotation.
  1942 
  1943 * New class "default" with associated constant "default".
  1944 
  1945 * Function "sgn" is now overloaded and available on int, real, complex
  1946 (and other numeric types), using class "sgn".  Two possible defs of
  1947 sgn are given as equational assumptions in the classes sgn_if and
  1948 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1949 INCOMPATIBILITY.
  1950 
  1951 * Locale "partial_order" now unified with class "order" (cf. theory
  1952 Orderings), added parameter "less".  INCOMPATIBILITY.
  1953 
  1954 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1955 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1956 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1957 
  1958 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1959 changed order of proof goals in instance proofs.
  1960 
  1961 * The transitivity reasoner for partial and linear orders is set up
  1962 for classes "order" and "linorder".  Instances of the reasoner are available
  1963 in all contexts importing or interpreting the corresponding locales.
  1964 Method "order" invokes the reasoner separately; the reasoner
  1965 is also integrated with the Simplifier as a solver.  Diagnostic
  1966 command 'print_orders' shows the available instances of the reasoner
  1967 in the current context.
  1968 
  1969 * Localized monotonicity predicate in theory "Orderings"; integrated
  1970 lemmas max_of_mono and min_of_mono with this predicate.
  1971 INCOMPATIBILITY.
  1972 
  1973 * Formulation of theorem "dense" changed slightly due to integration
  1974 with new class dense_linear_order.
  1975 
  1976 * Uniform lattice theory development in HOL.
  1977 
  1978     constants "meet" and "join" now named "inf" and "sup"
  1979     constant "Meet" now named "Inf"
  1980 
  1981     classes "meet_semilorder" and "join_semilorder" now named
  1982       "lower_semilattice" and "upper_semilattice"
  1983     class "lorder" now named "lattice"
  1984     class "comp_lat" now named "complete_lattice"
  1985 
  1986     Instantiation of lattice classes allows explicit definitions
  1987     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1988 
  1989   INCOMPATIBILITY.  Theorem renames:
  1990 
  1991     meet_left_le            ~> inf_le1
  1992     meet_right_le           ~> inf_le2
  1993     join_left_le            ~> sup_ge1
  1994     join_right_le           ~> sup_ge2
  1995     meet_join_le            ~> inf_sup_ord
  1996     le_meetI                ~> le_infI
  1997     join_leI                ~> le_supI
  1998     le_meet                 ~> le_inf_iff
  1999     le_join                 ~> ge_sup_conv
  2000     meet_idempotent         ~> inf_idem
  2001     join_idempotent         ~> sup_idem
  2002     meet_comm               ~> inf_commute
  2003     join_comm               ~> sup_commute
  2004     meet_leI1               ~> le_infI1
  2005     meet_leI2               ~> le_infI2
  2006     le_joinI1               ~> le_supI1
  2007     le_joinI2               ~> le_supI2
  2008     meet_assoc              ~> inf_assoc
  2009     join_assoc              ~> sup_assoc
  2010     meet_left_comm          ~> inf_left_commute
  2011     meet_left_idempotent    ~> inf_left_idem
  2012     join_left_comm          ~> sup_left_commute
  2013     join_left_idempotent    ~> sup_left_idem
  2014     meet_aci                ~> inf_aci
  2015     join_aci                ~> sup_aci
  2016     le_def_meet             ~> le_iff_inf
  2017     le_def_join             ~> le_iff_sup
  2018     join_absorp2            ~> sup_absorb2
  2019     join_absorp1            ~> sup_absorb1
  2020     meet_absorp1            ~> inf_absorb1
  2021     meet_absorp2            ~> inf_absorb2
  2022     meet_join_absorp        ~> inf_sup_absorb
  2023     join_meet_absorp        ~> sup_inf_absorb
  2024     distrib_join_le         ~> distrib_sup_le
  2025     distrib_meet_le         ~> distrib_inf_le
  2026 
  2027     add_meet_distrib_left   ~> add_inf_distrib_left
  2028     add_join_distrib_left   ~> add_sup_distrib_left
  2029     is_join_neg_meet        ~> is_join_neg_inf
  2030     is_meet_neg_join        ~> is_meet_neg_sup
  2031     add_meet_distrib_right  ~> add_inf_distrib_right
  2032     add_join_distrib_right  ~> add_sup_distrib_right
  2033     add_meet_join_distribs  ~> add_sup_inf_distribs
  2034     join_eq_neg_meet        ~> sup_eq_neg_inf
  2035     meet_eq_neg_join        ~> inf_eq_neg_sup
  2036     add_eq_meet_join        ~> add_eq_inf_sup
  2037     meet_0_imp_0            ~> inf_0_imp_0
  2038     join_0_imp_0            ~> sup_0_imp_0
  2039     meet_0_eq_0             ~> inf_0_eq_0
  2040     join_0_eq_0             ~> sup_0_eq_0
  2041     neg_meet_eq_join        ~> neg_inf_eq_sup
  2042     neg_join_eq_meet        ~> neg_sup_eq_inf
  2043     join_eq_if              ~> sup_eq_if
  2044 
  2045     mono_meet               ~> mono_inf
  2046     mono_join               ~> mono_sup
  2047     meet_bool_eq            ~> inf_bool_eq
  2048     join_bool_eq            ~> sup_bool_eq
  2049     meet_fun_eq             ~> inf_fun_eq
  2050     join_fun_eq             ~> sup_fun_eq
  2051     meet_set_eq             ~> inf_set_eq
  2052     join_set_eq             ~> sup_set_eq
  2053     meet1_iff               ~> inf1_iff
  2054     meet2_iff               ~> inf2_iff
  2055     meet1I                  ~> inf1I
  2056     meet2I                  ~> inf2I
  2057     meet1D1                 ~> inf1D1
  2058     meet2D1                 ~> inf2D1
  2059     meet1D2                 ~> inf1D2
  2060     meet2D2                 ~> inf2D2
  2061     meet1E                  ~> inf1E
  2062     meet2E                  ~> inf2E
  2063     join1_iff               ~> sup1_iff
  2064     join2_iff               ~> sup2_iff
  2065     join1I1                 ~> sup1I1
  2066     join2I1                 ~> sup2I1
  2067     join1I1                 ~> sup1I1
  2068     join2I2                 ~> sup1I2
  2069     join1CI                 ~> sup1CI
  2070     join2CI                 ~> sup2CI
  2071     join1E                  ~> sup1E
  2072     join2E                  ~> sup2E
  2073 
  2074     is_meet_Meet            ~> is_meet_Inf
  2075     Meet_bool_def           ~> Inf_bool_def
  2076     Meet_fun_def            ~> Inf_fun_def
  2077     Meet_greatest           ~> Inf_greatest
  2078     Meet_lower              ~> Inf_lower
  2079     Meet_set_def            ~> Inf_set_def
  2080 
  2081     Sup_def                 ~> Sup_Inf
  2082     Sup_bool_eq             ~> Sup_bool_def
  2083     Sup_fun_eq              ~> Sup_fun_def
  2084     Sup_set_eq              ~> Sup_set_def
  2085 
  2086     listsp_meetI            ~> listsp_infI
  2087     listsp_meet_eq          ~> listsp_inf_eq
  2088 
  2089     meet_min                ~> inf_min
  2090     join_max                ~> sup_max
  2091 
  2092 * Added syntactic class "size"; overloaded constant "size" now has
  2093 type "'a::size ==> bool"
  2094 
  2095 * Internal reorganisation of `size' of datatypes: size theorems
  2096 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2097 simplification rules by default!); theorems "prod.size" now named
  2098 "*.size".
  2099 
  2100 * Class "div" now inherits from class "times" rather than "type".
  2101 INCOMPATIBILITY.
  2102 
  2103 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2104 Linorder etc.  have disappeared; operations defined in terms of
  2105 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2106 
  2107 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2108 
  2109 * HOL-Word: New extensive library and type for generic, fixed size
  2110 machine words, with arithemtic, bit-wise, shifting and rotating
  2111 operations, reflection into int, nat, and bool lists, automation for
  2112 linear arithmetic (by automatic reflection into nat or int), including
  2113 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2114 arithmetic type classes, supporting automatic simplification of
  2115 numerals on all operations.
  2116 
  2117 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2118 
  2119 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2120 
  2121 * Code generator library theories:
  2122   - Code_Integer represents HOL integers by big integer literals in target
  2123     languages.
  2124   - Code_Char represents HOL characters by character literals in target
  2125     languages.
  2126   - Code_Char_chr like Code_Char, but also offers treatment of character
  2127     codes; includes Code_Integer.
  2128   - Executable_Set allows to generate code for finite sets using lists.
  2129   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2130     denominator).
  2131   - Executable_Real implements a subset of real numbers, namly those
  2132     representable by rational numbers.
  2133   - Efficient_Nat implements natural numbers by integers, which in general will
  2134     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2135     includes Code_Integer.
  2136   - Code_Index provides an additional datatype index which is mapped to
  2137     target-language built-in integers.
  2138   - Code_Message provides an additional datatype message_string which is isomorphic to
  2139     strings; messages are mapped to target-language strings.
  2140 
  2141 * New package for inductive predicates
  2142 
  2143   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2144 
  2145     inductive
  2146       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2147       for z_1 :: U_1 and ... and z_n :: U_m
  2148     where
  2149       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2150     | ...
  2151 
  2152   with full support for type-inference, rather than
  2153 
  2154     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2155 
  2156     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2157     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2158 
  2159     inductive "s z_1 ... z_m"
  2160     intros
  2161       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2162       ...
  2163 
  2164   For backward compatibility, there is a wrapper allowing inductive
  2165   sets to be defined with the new package via
  2166 
  2167     inductive_set
  2168       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2169       for z_1 :: U_1 and ... and z_n :: U_m
  2170     where
  2171       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2172     | ...
  2173 
  2174   or
  2175 
  2176     inductive_set
  2177       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2178       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2179       for z_1 :: U_1 and ... and z_n :: U_m
  2180     where
  2181       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2182     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2183     | ...
  2184 
  2185   if the additional syntax "p ..." is required.
  2186 
  2187   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2188   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2189 
  2190   INCOMPATIBILITIES:
  2191 
  2192   - Since declaration and definition of inductive sets or predicates
  2193     is no longer separated, abbreviations involving the newly
  2194     introduced sets or predicates must be specified together with the
  2195     introduction rules after the 'where' keyword (see above), rather
  2196     than before the actual inductive definition.
  2197 
  2198   - The variables in induction and elimination rules are now
  2199     quantified in the order of their occurrence in the introduction
  2200     rules, rather than in alphabetical order. Since this may break
  2201     some proofs, these proofs either have to be repaired, e.g. by
  2202     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2203     statements of the form
  2204 
  2205       case (rule_i a_i_1 ... a_i_{k_i})
  2206 
  2207     or the old order of quantification has to be restored by explicitly adding
  2208     meta-level quantifiers in the introduction rules, i.e.
  2209 
  2210       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2211 
  2212   - The format of the elimination rules is now
  2213 
  2214       p z_1 ... z_m x_1 ... x_n ==>
  2215         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2216         ==> ... ==> P
  2217 
  2218     for predicates and
  2219 
  2220       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2221         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2222         ==> ... ==> P
  2223 
  2224     for sets rather than
  2225 
  2226       x : s z_1 ... z_m ==>
  2227         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2228         ==> ... ==> P
  2229 
  2230     This may require terms in goals to be expanded to n-tuples
  2231     (e.g. using case_tac or simplification with the split_paired_all
  2232     rule) before the above elimination rule is applicable.
  2233 
  2234   - The elimination or case analysis rules for (mutually) inductive
  2235     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2236     list of rules "p_1_..._p_k.elims" is no longer available.
  2237 
  2238 * New package "function"/"fun" for general recursive functions,
  2239 supporting mutual and nested recursion, definitions in local contexts,
  2240 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2241 for small examples, and the separate tutorial on the function
  2242 package. The old recdef "package" is still available as before, but
  2243 users are encouraged to use the new package.
  2244 
  2245 * Method "lexicographic_order" automatically synthesizes termination
  2246 relations as lexicographic combinations of size measures. 
  2247 
  2248 * Case-expressions allow arbitrary constructor-patterns (including
  2249 "_") and take their order into account, like in functional
  2250 programming.  Internally, this is translated into nested
  2251 case-expressions; missing cases are added and mapped to the predefined
  2252 constant "undefined". In complicated cases printing may no longer show
  2253 the original input but the internal form. Lambda-abstractions allow
  2254 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2255 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2256 variable.
  2257 
  2258 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2259 is an abbreviation for "of_nat :: nat => int". The simplification
  2260 rules for "of_nat" have been changed to work like "int" did
  2261 previously.  Potential INCOMPATIBILITY:
  2262   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2263   - of_nat_diff and of_nat_mult are no longer default simp rules
  2264 
  2265 * Method "algebra" solves polynomial equations over (semi)rings using
  2266 Groebner bases. The (semi)ring structure is defined by locales and the
  2267 tool setup depends on that generic context. Installing the method for
  2268 a specific type involves instantiating the locale and possibly adding
  2269 declarations for computation on the coefficients.  The method is
  2270 already instantiated for natural numbers and for the axiomatic class
  2271 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2272 CALCULEMUS 2007 for the general principles underlying this
  2273 architecture of context-aware proof-tools.
  2274 
  2275 * Method "ferrack" implements quantifier elimination over
  2276 special-purpose dense linear orders using locales (analogous to
  2277 "algebra"). The method is already installed for class
  2278 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2279 rat, etc.
  2280 
  2281 * Former constant "List.op @" now named "List.append".  Use ML
  2282 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2283 circumvent possible incompatibilities when working on ML level.
  2284 
  2285 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2286 
  2287 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2288 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2289 
  2290 * New syntax for Haskell-like list comprehension (input only), eg.
  2291 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2292 
  2293 * The special syntax for function "filter" has changed from [x :
  2294 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2295 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2296 
  2297 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2298 defined on nat only, as an abbreviation for [a..<Suc b]
  2299 INCOMPATIBILITY.
  2300 
  2301 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2302 
  2303 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2304 
  2305 * New lemma collection field_simps (an extension of ring_simps) for
  2306 manipulating (in)equations involving division. Multiplies with all
  2307 denominators that can be proved to be non-zero (in equations) or
  2308 positive/negative (in inequations).
  2309 
  2310 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2311 have been improved and renamed to ring_simps, group_simps and
  2312 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2313 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2314 
  2315 * Theory Library/Commutative_Ring: switched from recdef to function
  2316 package; constants add, mul, pow now curried.  Infix syntax for
  2317 algebraic operations.
  2318 
  2319 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2320 INCOMPATIBILITY.
  2321 
  2322 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2323 INCOMPATIBILITY.
  2324 
  2325 * HOL/records: generalised field-update to take a function on the
  2326 field rather than the new value: r(|A := x|) is translated to A_update
  2327 (K x) r The K-combinator that is internally used is called K_record.
  2328 INCOMPATIBILITY: Usage of the plain update functions has to be
  2329 adapted.
  2330  
  2331 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2332 * x = 0, which are required for a semiring.  Richer structures do not
  2333 inherit from semiring_0 anymore, because this property is a theorem
  2334 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2335 there is more to prove, but this is mostly trivial.
  2336 
  2337 * Class "recpower" is generalized to arbitrary monoids, not just
  2338 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2339 commutativity or semiring properties additionally.
  2340 
  2341 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2342 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2343 better use 'abbreviation'.
  2344 
  2345 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2346 
  2347 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2348 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2349 significant changes for setting up numeral syntax for types:
  2350   - New constants Numeral.pred and Numeral.succ instead
  2351       of former Numeral.bin_pred and Numeral.bin_succ.
  2352   - Use integer operations instead of bin_add, bin_mult and so on.
  2353   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2354   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2355 
  2356 See src/HOL/Integ/IntArith.thy for an example setup.
  2357 
  2358 * Command 'normal_form' computes the normal form of a term that may
  2359 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2360 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2361 heavy-duty computations because the functions are compiled to ML
  2362 first.  Correspondingly, a method "normalization" is provided.  See
  2363 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2364 
  2365 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2366 25 like -->); output depends on the "iff" print_mode, the default is
  2367 "A = B" (with priority 50).
  2368 
  2369 * Relations less (<) and less_eq (<=) are also available on type bool.
  2370 Modified syntax to disallow nesting without explicit parentheses,
  2371 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2372 INCOMPATIBILITY.
  2373 
  2374 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2375 
  2376 * Relation composition operator "op O" now has precedence 75 and binds
  2377 stronger than union and intersection. INCOMPATIBILITY.
  2378 
  2379 * The old set interval syntax "{m..n(}" (and relatives) has been
  2380 removed.  Use "{m..<n}" (and relatives) instead.
  2381 
  2382 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2383 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2384 ``declare [[simproc del: neq]]''.
  2385 
  2386 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2387 True/False.
  2388 
  2389 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2390 
  2391 * Theorem setsum_mult renamed to setsum_right_distrib.
  2392 
  2393 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2394 ``rule'' method.
  2395 
  2396 * Reimplemented methods "sat" and "satx", with several improvements:
  2397 goals no longer need to be stated as "<prems> ==> False", equivalences
  2398 (i.e. "=" on type bool) are handled, variable names of the form
  2399 "lit_<n>" are no longer reserved, significant speedup.
  2400 
  2401 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2402 zChaff is still supported as well.
  2403 
  2404 * 'inductive' and 'datatype': provide projections of mutual rules,
  2405 bundled as foo_bar.inducts;
  2406 
  2407 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2408 Library.
  2409 
  2410 * Library: moved theory Accessible_Part to main HOL.
  2411 
  2412 * Library: added theory Coinductive_List of potentially infinite lists
  2413 as greatest fixed-point.
  2414 
  2415 * Library: added theory AssocList which implements (finite) maps as
  2416 association lists.
  2417 
  2418 * Method "evaluation" solves goals (i.e. a boolean expression)
  2419 efficiently by compiling it to ML.  The goal is "proved" (via an
  2420 oracle) if it evaluates to True.
  2421 
  2422 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2423 also when invoked by the simplifier.  This results in the Simplifier
  2424 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2425 Configuration option fast_arith_split_limit=0 recovers the old
  2426 behavior.
  2427 
  2428 * Support for hex (0x20) and binary (0b1001) numerals.
  2429 
  2430 * New method: reify eqs (t), where eqs are equations for an
  2431 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2432 parameter, computes a term s::'b and a list xs::'a list and proves the
  2433 theorem I xs s = t. This is also known as reification or quoting. The
  2434 resulting theorem is applied to the subgoal to substitute t with I xs
  2435 s.  If t is omitted, the subgoal itself is reified.
  2436 
  2437 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2438 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2439 where f is supposed to be a computable function (in the sense of code
  2440 generattion). The method uses reify to compute s and xs as above then
  2441 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2442 r and finally gets the theorem t = r, which is again applied to the
  2443 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2444 
  2445 * Reflection: Automatic reification now handels binding, an example is
  2446 available in src/HOL/ex/ReflectionEx.thy
  2447 
  2448 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2449 command 'statespace' that is similar to 'record', but introduces an
  2450 abstract specification based on the locale infrastructure instead of
  2451 HOL types.  This leads to extra flexibility in composing state spaces,
  2452 in particular multiple inheritance and renaming of components.
  2453 
  2454 
  2455 *** HOL-Complex ***
  2456 
  2457 * Hyperreal: Functions root and sqrt are now defined on negative real
  2458 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2459 Nonnegativity side conditions have been removed from many lemmas, so
  2460 that more subgoals may now be solved by simplification; potential
  2461 INCOMPATIBILITY.
  2462 
  2463 * Real: new type classes formalize real normed vector spaces and
  2464 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2465 and norm :: 'a => real.
  2466 
  2467 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2468 reals into other types. The overloaded constant Reals :: 'a set is now
  2469 defined as range of_real; potential INCOMPATIBILITY.
  2470 
  2471 * Real: proper support for ML code generation, including 'quickcheck'.
  2472 Reals are implemented as arbitrary precision rationals.
  2473 
  2474 * Hyperreal: Several constants that previously worked only for the
  2475 reals have been generalized, so they now work over arbitrary vector
  2476 spaces. Type annotations may need to be added in some cases; potential
  2477 INCOMPATIBILITY.
  2478 
  2479   Infinitesimal  :: ('a::real_normed_vector) star set
  2480   HFinite        :: ('a::real_normed_vector) star set
  2481   HInfinite      :: ('a::real_normed_vector) star set
  2482   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2483   monad          :: ('a::real_normed_vector) star => 'a star set
  2484   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2485   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2486   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2487   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2488   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2489   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2490   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2491   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2492   sgn            :: 'a::real_normed_vector => 'a
  2493   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2494 
  2495 * Complex: Some complex-specific constants are now abbreviations for
  2496 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2497 hnorm.  Other constants have been entirely removed in favor of the
  2498 polymorphic versions (INCOMPATIBILITY):
  2499 
  2500   approx        <-- capprox
  2501   HFinite       <-- CFinite
  2502   HInfinite     <-- CInfinite
  2503   Infinitesimal <-- CInfinitesimal
  2504   monad         <-- cmonad
  2505   galaxy        <-- cgalaxy
  2506   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2507   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2508   (ns)deriv     <-- (ns)cderiv
  2509 
  2510 
  2511 *** HOL-Algebra ***
  2512 
  2513 * Formalisation of ideals and the quotient construction over rings.
  2514 
  2515 * Order and lattice theory no longer based on records.
  2516 INCOMPATIBILITY.
  2517 
  2518 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2519 greatest_closed.  INCOMPATIBILITY.
  2520 
  2521 * Method algebra is now set up via an attribute.  For examples see
  2522 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2523 of algebraic structures.
  2524 
  2525 * Renamed theory CRing to Ring.
  2526 
  2527 
  2528 *** HOL-Nominal ***
  2529 
  2530 * Substantial, yet incomplete support for nominal datatypes (binding
  2531 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2532 src/HOL/Nominal/Examples.  Prospective users should consult
  2533 http://isabelle.in.tum.de/nominal/
  2534 
  2535 
  2536 *** ML ***
  2537 
  2538 * ML basics: just one true type int, which coincides with IntInf.int
  2539 (even on SML/NJ).
  2540 
  2541 * ML within Isar: antiquotations allow to embed statically-checked
  2542 formal entities in the source, referring to the context available at
  2543 compile-time.  For example:
  2544 
  2545 ML {* @{sort "{zero,one}"} *}
  2546 ML {* @{typ "'a => 'b"} *}
  2547 ML {* @{term "%x. x"} *}
  2548 ML {* @{prop "x == y"} *}
  2549 ML {* @{ctyp "'a => 'b"} *}
  2550 ML {* @{cterm "%x. x"} *}
  2551 ML {* @{cprop "x == y"} *}
  2552 ML {* @{thm asm_rl} *}
  2553 ML {* @{thms asm_rl} *}
  2554 ML {* @{type_name c} *}
  2555 ML {* @{type_syntax c} *}
  2556 ML {* @{const_name c} *}
  2557 ML {* @{const_syntax c} *}
  2558 ML {* @{context} *}
  2559 ML {* @{theory} *}
  2560 ML {* @{theory Pure} *}
  2561 ML {* @{theory_ref} *}
  2562 ML {* @{theory_ref Pure} *}
  2563 ML {* @{simpset} *}
  2564 ML {* @{claset} *}
  2565 ML {* @{clasimpset} *}
  2566 
  2567 The same works for sources being ``used'' within an Isar context.
  2568 
  2569 * ML in Isar: improved error reporting; extra verbosity with
  2570 ML_Context.trace enabled.
  2571 
  2572 * Pure/General/table.ML: the join operations now works via exceptions
  2573 DUP/SAME instead of type option. This is simpler in simple cases, and
  2574 admits slightly more efficient complex applications.
  2575 
  2576 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2577 use Context.generic instead of just theory.
  2578 
  2579 * Pure: datatype Context.generic joins theory/Proof.context and
  2580 provides some facilities for code that works in either kind of
  2581 context, notably GenericDataFun for uniform theory and proof data.
  2582 
  2583 * Pure: simplified internal attribute type, which is now always
  2584 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2585 local (Proof.context) attributes have been discontinued, while
  2586 minimizing code duplication. Thm.rule_attribute and
  2587 Thm.declaration_attribute build canonical attributes; see also structure
  2588 Context for further operations on Context.generic, notably
  2589 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2590 declarations and definitions.
  2591 
  2592 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2593 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2594 init only required for impure data. INCOMPATIBILITY: empty really need
  2595 to be empty (no dependencies on theory content!)
  2596 
  2597 * Pure/kernel: consts certification ignores sort constraints given in
  2598 signature declarations. (This information is not relevant to the
  2599 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2600 potential INCOMPATIBILITY.
  2601 
  2602 * Pure: axiomatic type classes are now purely definitional, with
  2603 explicit proofs of class axioms and super class relations performed
  2604 internally. See Pure/axclass.ML for the main internal interfaces --
  2605 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2606 AxClass.axiomatize_class/classrel/arity supersede
  2607 Sign.add_classes/classrel/arities.
  2608 
  2609 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2610 global/local versions on theory vs. Proof.context have been
  2611 discontinued; Attrib.syntax and Method.syntax have been adapted
  2612 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2613 attributes, methods, etc.
  2614 
  2615 * Pure: several functions of signature "... -> theory -> theory * ..."
  2616 have been reoriented to "... -> theory -> ... * theory" in order to
  2617 allow natural usage in combination with the ||>, ||>>, |-> and
  2618 fold_map combinators.
  2619 
  2620 * Pure: official theorem names (closed derivations) and additional
  2621 comments (tags) are now strictly separate.  Name hints -- which are
  2622 maintained as tags -- may be attached any time without affecting the
  2623 derivation.
  2624 
  2625 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2626 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2627 achieve the old behaviour.
  2628 
  2629 * Pure: the "Goal" constant is now called "prop", supporting a
  2630 slightly more general idea of ``protecting'' meta-level rule
  2631 statements.
  2632 
  2633 * Pure: Logic.(un)varify only works in a global context, which is now
  2634 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2635 Logic.legacy_(un)varify as temporary workaround.
  2636 
  2637 * Pure: structure Name provides scalable operations for generating
  2638 internal variable names, notably Name.variants etc.  This replaces
  2639 some popular functions from term.ML:
  2640 
  2641   Term.variant		->  Name.variant
  2642   Term.variantlist	->  Name.variant_list
  2643   Term.invent_names	->  Name.invent_list
  2644 
  2645 Note that low-level renaming rarely occurs in new code -- operations
  2646 from structure Variable are used instead (see below).
  2647 
  2648 * Pure: structure Variable provides fundamental operations for proper
  2649 treatment of fixed/schematic variables in a context.  For example,
  2650 Variable.import introduces fixes for schematics of given facts and
  2651 Variable.export reverses the effect (up to renaming) -- this replaces
  2652 various freeze_thaw operations.
  2653 
  2654 * Pure: structure Goal provides simple interfaces for
  2655 init/conclude/finish and tactical prove operations (replacing former
  2656 Tactic.prove).  Goal.prove is the canonical way to prove results
  2657 within a given context; Goal.prove_global is a degraded version for
  2658 theory level goals, including a global Drule.standard.  Note that
  2659 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2660 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2661 in a locale context).
  2662 
  2663 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2664 and type checking (Syntax.check_term etc.), with common combinations
  2665 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2666 which are considered legacy and await removal.
  2667 
  2668 * Pure/Syntax: generic interfaces for type unchecking
  2669 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2670 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2671 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2672 available for convenience, but refer to the very same operations using
  2673 a mere theory instead of a full context.
  2674 
  2675 * Isar: simplified treatment of user-level errors, using exception
  2676 ERROR of string uniformly.  Function error now merely raises ERROR,
  2677 without any side effect on output channels.  The Isar toplevel takes
  2678 care of proper display of ERROR exceptions.  ML code may use plain
  2679 handle/can/try; cat_error may be used to concatenate errors like this:
  2680 
  2681   ... handle ERROR msg => cat_error msg "..."
  2682 
  2683 Toplevel ML code (run directly or through the Isar toplevel) may be
  2684 embedded into the Isar toplevel with exception display/debug like
  2685 this:
  2686 
  2687   Isar.toplevel (fn () => ...)
  2688 
  2689 INCOMPATIBILITY, removed special transform_error facilities, removed
  2690 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2691 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2692 -- use plain ERROR instead.
  2693 
  2694 * Isar: theory setup now has type (theory -> theory), instead of a
  2695 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2696 
  2697 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2698 ProofContext.debug/verbose flags.
  2699 
  2700 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2701 theory before entering a proof state.  Transactions now always see a
  2702 quasi-functional intermediate checkpoint, both in interactive and
  2703 batch mode.
  2704 
  2705 * Isar: simplified interfaces for outer syntax.  Renamed
  2706 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2707 OuterSyntax.add_parsers -- this functionality is now included in
  2708 OuterSyntax.command etc.  INCOMPATIBILITY.
  2709 
  2710 * Simplifier: the simpset of a running simplification process now
  2711 contains a proof context (cf. Simplifier.the_context), which is the
  2712 very context that the initial simpset has been retrieved from (by
  2713 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2714 (solver, looper etc.) may depend on arbitrary proof data.
  2715 
  2716 * Simplifier.inherit_context inherits the proof context (plus the
  2717 local bounds) of the current simplification process; any simproc
  2718 etc. that calls the Simplifier recursively should do this!  Removed
  2719 former Simplifier.inherit_bounds, which is already included here --
  2720 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2721 specify an explicit context using Simplifier.context/theory_context.
  2722 
  2723 * Simplifier/Classical Reasoner: more abstract interfaces
  2724 change_simpset/claset for modifying the simpset/claset reference of a
  2725 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2726 INCOMPATIBILITY.
  2727 
  2728 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2729 "Trueprop" etc.
  2730 
  2731 
  2732 *** System ***
  2733 
  2734 * settings: the default heap location within ISABELLE_HOME_USER now
  2735 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2736 Isabelle installations.
  2737 
  2738 * isabelle-process: option -S (secure mode) disables some critical
  2739 operations, notably runtime compilation and evaluation of ML source
  2740 code.
  2741 
  2742 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2743 
  2744 * Support for parallel execution, using native multicore support of
  2745 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2746 independent theories, according to the given theory header
  2747 specifications. The maximum number of worker threads is specified via
  2748 usedir option -M or the "max-threads" setting in Proof General. A
  2749 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2750 to 6 on a 8-core machine.  User-code needs to observe certain
  2751 guidelines for thread-safe programming, see appendix A in the Isar
  2752 Implementation manual.
  2753 
  2754 
  2755 
  2756 New in Isabelle2005 (October 2005)
  2757 ----------------------------------
  2758 
  2759 *** General ***
  2760 
  2761 * Theory headers: the new header syntax for Isar theories is
  2762 
  2763   theory <name>
  2764   imports <theory1> ... <theoryN>
  2765   uses <file1> ... <fileM>
  2766   begin
  2767 
  2768 where the 'uses' part is optional.  The previous syntax
  2769 
  2770   theory <name> = <theory1> + ... + <theoryN>:
  2771 
  2772 will disappear in the next release.  Use isatool fixheaders to convert
  2773 existing theory files.  Note that there is no change in ancient
  2774 non-Isar theories now, but these will disappear soon.
  2775 
  2776 * Theory loader: parent theories can now also be referred to via
  2777 relative and absolute paths.
  2778 
  2779 * Command 'find_theorems' searches for a list of criteria instead of a
  2780 list of constants. Known criteria are: intro, elim, dest, name:string,
  2781 simp:term, and any term. Criteria can be preceded by '-' to select
  2782 theorems that do not match. Intro, elim, dest select theorems that
  2783 match the current goal, name:s selects theorems whose fully qualified
  2784 name contain s, and simp:term selects all simplification rules whose
  2785 lhs match term.  Any other term is interpreted as pattern and selects
  2786 all theorems matching the pattern. Available in ProofGeneral under
  2787 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2788 
  2789   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2790 
  2791 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2792 matching the current goal as introduction rule and not having "HOL."
  2793 in their name (i.e. not being defined in theory HOL).
  2794 
  2795 * Command 'thms_containing' has been discontinued in favour of
  2796 'find_theorems'; INCOMPATIBILITY.
  2797 
  2798 * Communication with Proof General is now 8bit clean, which means that
  2799 Unicode text in UTF-8 encoding may be used within theory texts (both
  2800 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2801 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2802 
  2803   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2804   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2805 
  2806 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2807 Classical Reasoner.  Typical big applications run around 2 times
  2808 faster.
  2809 
  2810 
  2811 *** Document preparation ***
  2812 
  2813 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2814 of raw sources.  Only those symbols that do not require additional
  2815 LaTeX packages (depending on comments in isabellesym.sty) are
  2816 displayed properly, everything else is left verbatim.  isatool display
  2817 and isatool print are used as front ends (these are subject to the
  2818 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2819 
  2820 * Command tags control specific markup of certain regions of text,
  2821 notably folding and hiding.  Predefined tags include "theory" (for
  2822 theory begin and end), "proof" for proof commands, and "ML" for
  2823 commands involving ML code; the additional tags "visible" and
  2824 "invisible" are unused by default.  Users may give explicit tag
  2825 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2826 interpretation of tags is determined by the LaTeX job during document
  2827 preparation: see option -V of isatool usedir, or options -n and -t of
  2828 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2829 \isadroptag.
  2830 
  2831 Several document versions may be produced at the same time via isatool
  2832 usedir (the generated index.html will link all of them).  Typical
  2833 specifications include ''-V document=theory,proof,ML'' to present
  2834 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2835 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2836 these parts without any formal replacement text.  The Isabelle site
  2837 default settings produce ''document'' and ''outline'' versions as
  2838 specified above.
  2839 
  2840 * Several new antiquotations:
  2841 
  2842   @{term_type term} prints a term with its type annotated;
  2843 
  2844   @{typeof term} prints the type of a term;
  2845 
  2846   @{const const} is the same as @{term const}, but checks that the
  2847   argument is a known logical constant;
  2848 
  2849   @{term_style style term} and @{thm_style style thm} print a term or
  2850   theorem applying a "style" to it
  2851 
  2852   @{ML text}
  2853 
  2854 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2855 definitions, equations, inequations etc., 'concl' printing only the
  2856 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2857 to print the specified premise.  TermStyle.add_style provides an ML
  2858 interface for introducing further styles.  See also the "LaTeX Sugar"
  2859 document practical applications.  The ML antiquotation prints
  2860 type-checked ML expressions verbatim.
  2861 
  2862 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2863 and 'text' support optional locale specification '(in loc)', which
  2864 specifies the default context for interpreting antiquotations.  For
  2865 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2866 
  2867 * Option 'locale=NAME' of antiquotations specifies an alternative
  2868 context interpreting the subsequent argument.  For example: @{thm
  2869 [locale=lattice] inf_assoc}.
  2870 
  2871 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2872 a proof context.
  2873 
  2874 * Proper output of antiquotations for theory commands involving a
  2875 proof context (such as 'locale' or 'theorem (in loc) ...').
  2876 
  2877 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2878 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2879 
  2880 * isatool usedir: new option -C (default true) controls whether option
  2881 -D should include a copy of the original document directory; -C false
  2882 prevents unwanted effects such as copying of administrative CVS data.
  2883 
  2884 
  2885 *** Pure ***
  2886 
  2887 * Considerably improved version of 'constdefs' command.  Now performs
  2888 automatic type-inference of declared constants; additional support for
  2889 local structure declarations (cf. locales and HOL records), see also
  2890 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2891 sequential dependencies of definitions within a single 'constdefs'
  2892 section; moreover, the declared name needs to be an identifier.  If
  2893 all fails, consider to fall back on 'consts' and 'defs' separately.
  2894 
  2895 * Improved indexed syntax and implicit structures.  First of all,
  2896 indexed syntax provides a notational device for subscripted
  2897 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2898 expressions.  Secondly, in a local context with structure
  2899 declarations, number indexes \<^sub>n or the empty index (default
  2900 number 1) refer to a certain fixed variable implicitly; option
  2901 show_structs controls printing of implicit structures.  Typical
  2902 applications of these concepts involve record types and locales.
  2903 
  2904 * New command 'no_syntax' removes grammar declarations (and
  2905 translations) resulting from the given syntax specification, which is
  2906 interpreted in the same manner as for the 'syntax' command.
  2907 
  2908 * 'Advanced' translation functions (parse_translation etc.) may depend
  2909 on the signature of the theory context being presently used for
  2910 parsing/printing, see also isar-ref manual.
  2911 
  2912 * Improved 'oracle' command provides a type-safe interface to turn an
  2913 ML expression of type theory -> T -> term into a primitive rule of
  2914 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2915 is already included here); see also FOL/ex/IffExample.thy;
  2916 INCOMPATIBILITY.
  2917 
  2918 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2919 before); "cI" is no longer bound, use "c.intro" instead.
  2920 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2921 axclasses vs. locales.
  2922 
  2923 * Improved internal renaming of symbolic identifiers -- attach primes
  2924 instead of base 26 numbers.
  2925 
  2926 * New flag show_question_marks controls printing of leading question
  2927 marks in schematic variable names.
  2928 
  2929 * In schematic variable names, *any* symbol following \<^isub> or
  2930 \<^isup> is now treated as part of the base name.  For example, the
  2931 following works without printing of awkward ".0" indexes:
  2932 
  2933   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2934     by simp
  2935 
  2936 * Inner syntax includes (*(*nested*) comments*).
  2937 
  2938 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2939 annotations as "(00...)".
  2940 
  2941 * Clear separation of logical types and nonterminals, where the latter
  2942 may only occur in 'syntax' specifications or type abbreviations.
  2943 Before that distinction was only partially implemented via type class
  2944 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2945 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2946 exotic syntax specifications may require further adaption
  2947 (e.g. Cube/Cube.thy).
  2948 
  2949 * Removed obsolete type class "logic", use the top sort {} instead.
  2950 Note that non-logical types should be declared as 'nonterminals'
  2951 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2952 specifications.
  2953 
  2954 * Attributes 'induct' and 'cases': type or set names may now be
  2955 locally fixed variables as well.
  2956 
  2957 * Simplifier: can now control the depth to which conditional rewriting
  2958 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2959 Limit.
  2960 
  2961 * Simplifier: simplification procedures may now take the current
  2962 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2963 interface), which is very useful for calling the Simplifier
  2964 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2965 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2966 low-level mk_simproc no longer applies Logic.varify internally, to
  2967 allow for use in a context of fixed variables.
  2968 
  2969 * thin_tac now works even if the assumption being deleted contains !!
  2970 or ==>.  More generally, erule now works even if the major premise of
  2971 the elimination rule contains !! or ==>.
  2972 
  2973 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2974 
  2975 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2976 from Pure, which contains all common declarations already.  Both
  2977 theories are defined via plain Isabelle/Isar .thy files.
  2978 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2979 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2980 use isatool fixcpure to adapt your theory and ML sources.
  2981 
  2982 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2983 selections of theorems in named facts via index ranges.
  2984 
  2985 * 'print_theorems': in theory mode, really print the difference
  2986 wrt. the last state (works for interactive theory development only),
  2987 in proof mode print all local facts (cf. 'print_facts');
  2988 
  2989 * 'hide': option '(open)' hides only base names.
  2990 
  2991 * More efficient treatment of intermediate checkpoints in interactive
  2992 theory development.
  2993 
  2994 * Code generator is now invoked via code_module (incremental code
  2995 generation) and code_library (modular code generation, ML structures
  2996 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  2997 must be quoted when used as identifiers.
  2998 
  2999 * New 'value' command for reading, evaluating and printing terms using
  3000 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3001 quoted when used as identifier.
  3002 
  3003 
  3004 *** Locales ***
  3005 
  3006 * New commands for the interpretation of locale expressions in
  3007 theories (1), locales (2) and proof contexts (3).  These generate
  3008 proof obligations from the expression specification.  After the
  3009 obligations have been discharged, theorems of the expression are added
  3010 to the theory, target locale or proof context.  The synopsis of the
  3011 commands is a follows:
  3012 
  3013   (1) interpretation expr inst
  3014   (2) interpretation target < expr
  3015   (3) interpret expr inst
  3016 
  3017 Interpretation in theories and proof contexts require a parameter
  3018 instantiation of terms from the current context.  This is applied to
  3019 specifications and theorems of the interpreted expression.
  3020 Interpretation in locales only permits parameter renaming through the
  3021 locale expression.  Interpretation is smart in that interpretations
  3022 that are active already do not occur in proof obligations, neither are
  3023 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3024 inspect active interpretations of a particular locale.  For details,
  3025 see the Isar Reference manual.  Examples can be found in
  3026 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3027 
  3028 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3029 'interpret' instead.
  3030 
  3031 * New context element 'constrains' for adding type constraints to
  3032 parameters.
  3033 
  3034 * Context expressions: renaming of parameters with syntax
  3035 redeclaration.
  3036 
  3037 * Locale declaration: 'includes' disallowed.
  3038 
  3039 * Proper static binding of attribute syntax -- i.e. types / terms /
  3040 facts mentioned as arguments are always those of the locale definition
  3041 context, independently of the context of later invocations.  Moreover,
  3042 locale operations (renaming and type / term instantiation) are applied
  3043 to attribute arguments as expected.
  3044 
  3045 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3046 actual attributes; rare situations may require Attrib.attribute to
  3047 embed those attributes into Attrib.src that lack concrete syntax.
  3048 Attribute implementations need to cooperate properly with the static
  3049 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3050 Attrib.XXX_thm etc. already do the right thing without further
  3051 intervention.  Only unusual applications -- such as "where" or "of"
  3052 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3053 on the context and the facts involved -- may have to assign parsed
  3054 values to argument tokens explicitly.
  3055 
  3056 * Changed parameter management in theorem generation for long goal
  3057 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3058 theorem statement in rare situations.
  3059 
  3060 * Locale inspection command 'print_locale' omits notes elements.  Use
  3061 'print_locale!' to have them included in the output.
  3062 
  3063 
  3064 *** Provers ***
  3065 
  3066 * Provers/hypsubst.ML: improved version of the subst method, for
  3067 single-step rewriting: it now works in bound variable contexts. New is
  3068 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3069 rewrite a different subterm than the original subst method, which is
  3070 still available as 'simplesubst'.
  3071 
  3072 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3073 and quasi orders.
  3074 
  3075 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3076 reflexive-transitive closure of relations.
  3077 
  3078 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3079 limit (previously hard-coded with a value of 20) user-definable.
  3080 
  3081 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3082 is peformed already.  Object-logics merely need to finish their
  3083 initial simpset configuration as before.  INCOMPATIBILITY.
  3084 
  3085 
  3086 *** HOL ***
  3087 
  3088 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3089 
  3090   syntax (epsilon)
  3091     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3092 
  3093 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3094 and x-symbol; use option '-m epsilon' to get it actually printed.
  3095 Moreover, the mathematically important symbolic identifier \<epsilon>
  3096 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3097 
  3098 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3099 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3100 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3101 support corresponding Isar calculations.
  3102 
  3103 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3104 instead of ":".
  3105 
  3106 * theory SetInterval: changed the syntax for open intervals:
  3107 
  3108   Old       New
  3109   {..n(}    {..<n}
  3110   {)n..}    {n<..}
  3111   {m..n(}   {m..<n}
  3112   {)m..n}   {m<..n}
  3113   {)m..n(}  {m<..<n}
  3114 
  3115 The old syntax is still supported but will disappear in the next
  3116 release.  For conversion use the following Emacs search and replace
  3117 patterns (these are not perfect but work quite well):
  3118 
  3119   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3120   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3121 
  3122 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3123 equalities in commutative rings; method 'algebra' provides a generic
  3124 interface.
  3125 
  3126 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3127 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3128 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3129 be a tuple pattern.
  3130 
  3131 Some new syntax forms are available:
  3132 
  3133   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3134   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3135   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3136   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3137 
  3138 The latter form "\<Sum>x < k. e" used to be based on a separate
  3139 function "Summation", which has been discontinued.
  3140 
  3141 * theory Finite_Set: in structured induction proofs, the insert case
  3142 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3143 (insert F x)'.
  3144 
  3145 * The 'refute' command has been extended to support a much larger
  3146 fragment of HOL, including axiomatic type classes, constdefs and
  3147 typedefs, inductive datatypes and recursion.
  3148 
  3149 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3150 Requires zChaff with proof generation to be installed.  See
  3151 HOL/ex/SAT_Examples.thy for examples.
  3152 
  3153 * Datatype induction via method 'induct' now preserves the name of the
  3154 induction variable. For example, when proving P(xs::'a list) by
  3155 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3156 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3157 in unstructured proof scripts.
  3158 
  3159 * Reworked implementation of records.  Improved scalability for
  3160 records with many fields, avoiding performance problems for type
  3161 inference. Records are no longer composed of nested field types, but
  3162 of nested extension types. Therefore the record type only grows linear
  3163 in the number of extensions and not in the number of fields.  The
  3164 top-level (users) view on records is preserved.  Potential
  3165 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3166 old record representation. The type generated for a record is called
  3167 <record_name>_ext_type.
  3168 
  3169 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3170 proofs triggered by a record definition or a simproc (if
  3171 quick_and_dirty is enabled).  Definitions of large records can take
  3172 quite long.
  3173 
  3174 New simproc record_upd_simproc for simplification of multiple record
  3175 updates enabled by default.  Moreover, trivial updates are also
  3176 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3177 occasionally, since simplification is more powerful by default.
  3178 
  3179 * typedef: proper support for polymorphic sets, which contain extra
  3180 type-variables in the term.
  3181 
  3182 * Simplifier: automatically reasons about transitivity chains
  3183 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3184 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3185 old proofs break occasionally as simplification may now solve more
  3186 goals than previously.
  3187 
  3188 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3189 present.  Works for all partial orders (class "order"), in particular
  3190 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3191 just like y <= x.
  3192 
  3193 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3194 bound variable or a constant then the let is unfolded.  Otherwise
  3195 first a is simplified to b, and then f b is simplified to g. If
  3196 possible we abstract b from g arriving at "let x = b in h x",
  3197 otherwise we unfold the let and arrive at g.  The simproc can be
  3198 enabled/disabled by the reference use_let_simproc.  Potential
  3199 INCOMPATIBILITY since simplification is more powerful by default.
  3200 
  3201 * Classical reasoning: the meson method now accepts theorems as arguments.
  3202 
  3203 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3204 jobs to provide advice on the provability of subgoals.
  3205 
  3206 * Theory OrderedGroup and Ring_and_Field: various additions and
  3207 improvements to faciliate calculations involving equalities and
  3208 inequalities.
  3209 
  3210 The following theorems have been eliminated or modified
  3211 (INCOMPATIBILITY):
  3212 
  3213   abs_eq             now named abs_of_nonneg
  3214   abs_of_ge_0        now named abs_of_nonneg
  3215   abs_minus_eq       now named abs_of_nonpos
  3216   imp_abs_id         now named abs_of_nonneg
  3217   imp_abs_neg_id     now named abs_of_nonpos
  3218   mult_pos           now named mult_pos_pos
  3219   mult_pos_le        now named mult_nonneg_nonneg
  3220   mult_pos_neg_le    now named mult_nonneg_nonpos
  3221   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3222   mult_neg           now named mult_neg_neg
  3223   mult_neg_le        now named mult_nonpos_nonpos
  3224 
  3225 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3226      
  3227      zero_le_square
  3228      not_square_less_zero 
  3229 
  3230   The following lemmas have been deleted from Real/RealPow:
  3231   
  3232      realpow_zero_zero
  3233      realpow_two
  3234      realpow_less
  3235      zero_le_power
  3236      realpow_two_le
  3237      abs_realpow_two
  3238      realpow_two_abs     
  3239 
  3240 * Theory Parity: added rules for simplifying exponents.
  3241 
  3242 * Theory List:
  3243 
  3244 The following theorems have been eliminated or modified
  3245 (INCOMPATIBILITY):
  3246 
  3247   list_all_Nil       now named list_all.simps(1)
  3248   list_all_Cons      now named list_all.simps(2)
  3249   list_all_conv      now named list_all_iff
  3250   set_mem_eq         now named mem_iff
  3251 
  3252 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3253 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3254 
  3255 
  3256 *** HOL-Complex ***
  3257 
  3258 * Theory RealDef: better support for embedding natural numbers and
  3259 integers in the reals.
  3260 
  3261 The following theorems have been eliminated or modified
  3262 (INCOMPATIBILITY):
  3263 
  3264   exp_ge_add_one_self  now requires no hypotheses
  3265   real_of_int_add      reversed direction of equality (use [symmetric])
  3266   real_of_int_minus    reversed direction of equality (use [symmetric])
  3267   real_of_int_diff     reversed direction of equality (use [symmetric])
  3268   real_of_int_mult     reversed direction of equality (use [symmetric])
  3269 
  3270 * Theory RComplete: expanded support for floor and ceiling functions.
  3271 
  3272 * Theory Ln is new, with properties of the natural logarithm
  3273 
  3274 * Hyperreal: There is a new type constructor "star" for making
  3275 nonstandard types.  The old type names are now type synonyms:
  3276 
  3277   hypreal = real star
  3278   hypnat = nat star
  3279   hcomplex = complex star
  3280 
  3281 * Hyperreal: Many groups of similarly-defined constants have been
  3282 replaced by polymorphic versions (INCOMPATIBILITY):
  3283 
  3284   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3285 
  3286   starset      <-- starsetNat, starsetC
  3287   *s*          <-- *sNat*, *sc*
  3288   starset_n    <-- starsetNat_n, starsetC_n
  3289   *sn*         <-- *sNatn*, *scn*
  3290   InternalSets <-- InternalNatSets, InternalCSets
  3291 
  3292   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3293   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3294   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3295   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3296   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3297 
  3298 * Hyperreal: Many type-specific theorems have been removed in favor of
  3299 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3300 
  3301   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3302   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3303   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3304   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3305   right_minus <-- hypreal_add_minus
  3306   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3307   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3308   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3309   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3310   mult_1_right <-- hcomplex_mult_one_right
  3311   mult_zero_left <-- hcomplex_mult_zero_left
  3312   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3313   right_distrib <-- hypnat_add_mult_distrib2
  3314   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3315   right_inverse <-- hypreal_mult_inverse
  3316   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3317   order_refl <-- {hypreal,hypnat}_le_refl
  3318   order_trans <-- {hypreal,hypnat}_le_trans
  3319   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3320   order_less_le <-- {hypreal,hypnat}_less_le
  3321   linorder_linear <-- {hypreal,hypnat}_le_linear
  3322   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3323   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3324   add_nonneg_nonneg <-- hypreal_le_add_order
  3325 
  3326 * Hyperreal: Separate theorems having to do with type-specific
  3327 versions of constants have been merged into theorems that apply to the
  3328 new polymorphic constants (INCOMPATIBILITY):
  3329 
  3330   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3331   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3332   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3333   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3334   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3335   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3336   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3337   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3338   STAR_diff <-- {STAR,STARC}_diff
  3339   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3340     STARC_hcomplex_of_complex}_image_subset
  3341   starset_n_Un <-- starset{Nat,C}_n_Un
  3342   starset_n_Int <-- starset{Nat,C}_n_Int
  3343   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3344   starset_n_diff <-- starset{Nat,C}_n_diff
  3345   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3346   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3347   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3348   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3349   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3350   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3351   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3352   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3353   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3354   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3355   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3356   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3357   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3358   starfun_diff <-- starfun{C,RC,CR}_diff
  3359   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3360   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3361   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3362   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3363   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3364   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3365   starfun_Id <-- starfunC_Id
  3366   starfun_approx <-- starfun{Nat,CR}_approx
  3367   starfun_capprox <-- starfun{C,RC}_capprox
  3368   starfun_abs <-- starfunNat_rabs
  3369   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3370   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3371   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3372   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3373   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3374   starfun_add_approx <-- starfunCR_add_approx
  3375   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3376   starfun_divide <-- starfun{C,CR,RC}_divide
  3377   starfun_n <-- starfun{Nat,C}_n
  3378   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3379   starfun_n_add <-- starfun{Nat,C}_n_add
  3380   starfun_n_add_minus <-- starfunNat_n_add_minus
  3381   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3382   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3383   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3384 
  3385   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3386   star_n_minus <-- {hypreal,hcomplex}_minus
  3387   star_n_diff <-- {hypreal,hcomplex}_diff
  3388   star_n_mult <-- {hypreal,hcomplex}_mult
  3389   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3390   star_n_le <-- {hypreal,hypnat}_le
  3391   star_n_less <-- {hypreal,hypnat}_less
  3392   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3393   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3394   star_n_abs <-- hypreal_hrabs
  3395   star_n_divide <-- hcomplex_divide
  3396 
  3397   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3398   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3399   star_of_diff <-- hypreal_of_real_diff
  3400   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3401   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3402   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3403   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3404   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3405   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3406   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3407   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3408   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3409   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3410   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3411   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3412   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3413   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3414   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3415   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3416   star_of_power <-- hypreal_of_real_power
  3417   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3418 
  3419 * Hyperreal: new method "transfer" that implements the transfer
  3420 principle of nonstandard analysis. With a subgoal that mentions
  3421 nonstandard types like "'a star", the command "apply transfer"
  3422 replaces it with an equivalent one that mentions only standard types.
  3423 To be successful, all free variables must have standard types; non-
  3424 standard variables must have explicit universal quantifiers.
  3425 
  3426 * Hyperreal: A theory of Taylor series.
  3427 
  3428 
  3429 *** HOLCF ***
  3430 
  3431 * Discontinued special version of 'constdefs' (which used to support
  3432 continuous functions) in favor of the general Pure one with full
  3433 type-inference.
  3434 
  3435 * New simplification procedure for solving continuity conditions; it
  3436 is much faster on terms with many nested lambda abstractions (cubic
  3437 instead of exponential time).
  3438 
  3439 * New syntax for domain package: selector names are now optional.
  3440 Parentheses should be omitted unless argument is lazy, for example:
  3441 
  3442   domain 'a stream = cons "'a" (lazy "'a stream")
  3443 
  3444 * New command 'fixrec' for defining recursive functions with pattern
  3445 matching; defining multiple functions with mutual recursion is also
  3446 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3447 sinr, or any data constructor defined by the domain package. The given
  3448 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3449 syntax and examples.
  3450 
  3451 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3452 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3453 but the proof obligation additionally includes an admissibility
  3454 requirement. The packages generate instances of class cpo or pcpo,
  3455 with continuity and strictness theorems for Rep and Abs.
  3456 
  3457 * HOLCF: Many theorems have been renamed according to a more standard naming
  3458 scheme (INCOMPATIBILITY):
  3459 
  3460   foo_inject:  "foo$x = foo$y ==> x = y"
  3461   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3462   foo_less:    "(foo$x << foo$y) = (x << y)"
  3463   foo_strict:  "foo$UU = UU"
  3464   foo_defined: "... ==> foo$x ~= UU"
  3465   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3466 
  3467 
  3468 *** ZF ***
  3469 
  3470 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3471 including the First Isomorphism Theorem (on quotienting by the kernel
  3472 of a homomorphism).
  3473 
  3474 * ZF/Simplifier: install second copy of type solver that actually
  3475 makes use of TC rules declared to Isar proof contexts (or locales);
  3476 the old version is still required for ML proof scripts.
  3477 
  3478 
  3479 *** Cube ***
  3480 
  3481 * Converted to Isar theory format; use locales instead of axiomatic
  3482 theories.
  3483 
  3484 
  3485 *** ML ***
  3486 
  3487 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3488 for ||>, ||>>, |>>,
  3489 
  3490 * Pure/library.ML no longer defines its own option datatype, but uses
  3491 that of the SML basis, which has constructors NONE and SOME instead of
  3492 None and Some, as well as exception Option.Option instead of OPTION.
  3493 The functions the, if_none, is_some, is_none have been adapted
  3494 accordingly, while Option.map replaces apsome.
  3495 
  3496 * Pure/library.ML: the exception LIST has been given up in favour of
  3497 the standard exceptions Empty and Subscript, as well as
  3498 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3499 superceded by the standard hd and tl functions etc.
  3500 
  3501 A number of basic list functions are no longer exported to the ML
  3502 toplevel, as they are variants of predefined functions.  The following
  3503 suggests how one can translate existing code:
  3504 
  3505     rev_append xs ys = List.revAppend (xs, ys)
  3506     nth_elem (i, xs) = List.nth (xs, i)
  3507     last_elem xs = List.last xs
  3508     flat xss = List.concat xss
  3509     seq fs = List.app fs
  3510     partition P xs = List.partition P xs
  3511     mapfilter f xs = List.mapPartial f xs
  3512 
  3513 * Pure/library.ML: several combinators for linear functional
  3514 transformations, notably reverse application and composition:
  3515 
  3516   x |> f                f #> g
  3517   (x, y) |-> f          f #-> g
  3518 
  3519 * Pure/library.ML: introduced/changed precedence of infix operators:
  3520 
  3521   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3522   infix 2 ?;
  3523   infix 3 o oo ooo oooo;
  3524   infix 4 ~~ upto downto;
  3525 
  3526 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3527 infix operators.
  3528 
  3529 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3530 fold_map support linear functional transformations and nesting.  For
  3531 example:
  3532 
  3533   fold f [x1, ..., xN] y =
  3534     y |> f x1 |> ... |> f xN
  3535 
  3536   (fold o fold) f [xs1, ..., xsN] y =
  3537     y |> fold f xs1 |> ... |> fold f xsN
  3538 
  3539   fold f [x1, ..., xN] =
  3540     f x1 #> ... #> f xN
  3541 
  3542   (fold o fold) f [xs1, ..., xsN] =
  3543     fold f xs1 #> ... #> fold f xsN
  3544 
  3545 * Pure/library.ML: the following selectors on type 'a option are
  3546 available:
  3547 
  3548   the:               'a option -> 'a  (*partial*)
  3549   these:             'a option -> 'a  where 'a = 'b list
  3550   the_default: 'a -> 'a option -> 'a
  3551   the_list:          'a option -> 'a list
  3552 
  3553 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3554 basic operations for association lists, following natural argument
  3555 order; moreover the explicit equality predicate passed here avoids
  3556 potentially expensive polymorphic runtime equality checks.
  3557 The old functions may be expressed as follows:
  3558 
  3559   assoc = uncurry (AList.lookup (op =))
  3560   assocs = these oo AList.lookup (op =)
  3561   overwrite = uncurry (AList.update (op =)) o swap
  3562 
  3563 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3564 
  3565   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3566   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3567 
  3568 replacing make_keylist and keyfilter (occassionally used)
  3569 Naive rewrites:
  3570 
  3571   make_keylist = AList.make
  3572   keyfilter = AList.find (op =)
  3573 
  3574 * eq_fst and eq_snd now take explicit equality parameter, thus
  3575   avoiding eqtypes. Naive rewrites:
  3576 
  3577     eq_fst = eq_fst (op =)
  3578     eq_snd = eq_snd (op =)
  3579 
  3580 * Removed deprecated apl and apr (rarely used).
  3581   Naive rewrites:
  3582 
  3583     apl (n, op) =>>= curry op n
  3584     apr (op, m) =>>= fn n => op (n, m)
  3585 
  3586 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3587 provides a reasonably efficient light-weight implementation of sets as
  3588 lists.
  3589 
  3590 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3591 few new operations; existing lookup and update are now curried to
  3592 follow natural argument order (for use with fold etc.);
  3593 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3594 
  3595 * Pure/General: output via the Isabelle channels of
  3596 writeln/warning/error etc. is now passed through Output.output, with a
  3597 hook for arbitrary transformations depending on the print_mode
  3598 (cf. Output.add_mode -- the first active mode that provides a output
  3599 function wins).  Already formatted output may be embedded into further
  3600 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3601 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3602 accommodate easy composition of diagnostic messages etc.  Programmers
  3603 rarely need to care about Output.output or Output.raw at all, with
  3604 some notable exceptions: Output.output is required when bypassing the
  3605 standard channels (writeln etc.), or in token translations to produce
  3606 properly formatted results; Output.raw is required when capturing
  3607 already output material that will eventually be presented to the user
  3608 a second time.  For the default print mode, both Output.output and
  3609 Output.raw have no effect.
  3610 
  3611 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3612 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3613 cumulative results are displayed at the end of a batch session.
  3614 
  3615 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3616 replaced by File.platform_path and File.shell_path (with appropriate
  3617 hooks).  This provides a clean interface for unusual systems where the
  3618 internal and external process view of file names are different.
  3619 
  3620 * Pure: more efficient orders for basic syntactic entities: added
  3621 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3622 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3623 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3624 orders now -- potential INCOMPATIBILITY for code that depends on a
  3625 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3626 Library.sort_strings on result).
  3627 
  3628 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3629 fold_types traverse types/terms from left to right, observing natural
  3630 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3631 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3632 
  3633 * Pure: name spaces have been refined, with significant changes of the
  3634 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3635 to extern(_table).  The plain name entry path is superceded by a
  3636 general 'naming' context, which also includes the 'policy' to produce
  3637 a fully qualified name and external accesses of a fully qualified
  3638 name; NameSpace.extend is superceded by context dependent
  3639 Sign.declare_name.  Several theory and proof context operations modify
  3640 the naming context.  Especially note Theory.restore_naming and
  3641 ProofContext.restore_naming to get back to a sane state; note that
  3642 Theory.add_path is no longer sufficient to recover from
  3643 Theory.absolute_path in particular.
  3644 
  3645 * Pure: new flags short_names (default false) and unique_names
  3646 (default true) for controlling output of qualified names.  If
  3647 short_names is set, names are printed unqualified.  If unique_names is
  3648 reset, the name prefix is reduced to the minimum required to achieve
  3649 the original result when interning again, even if there is an overlap
  3650 with earlier declarations.
  3651 
  3652 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3653 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3654 (useful for printing error messages).  INCOMPATIBILITY.
  3655 
  3656 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3657 Theory.theory are now identified, referring to the universal
  3658 Context.theory (see Pure/context.ML).  Actual signature and theory
  3659 content is managed as theory data.  The old code and interfaces were
  3660 spread over many files and structures; the new arrangement introduces
  3661 considerable INCOMPATIBILITY to gain more clarity:
  3662 
  3663   Context -- theory management operations (name, identity, inclusion,
  3664     parents, ancestors, merge, etc.), plus generic theory data;
  3665 
  3666   Sign -- logical signature and syntax operations (declaring consts,
  3667     types, etc.), plus certify/read for common entities;
  3668 
  3669   Theory -- logical theory operations (stating axioms, definitions,
  3670     oracles), plus a copy of logical signature operations (consts,
  3671     types, etc.); also a few basic management operations (Theory.copy,
  3672     Theory.merge, etc.)
  3673 
  3674 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3675 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3676 for convenience -- they merely return the theory.
  3677 
  3678 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3679 
  3680 * Pure: the Isar proof context type is already defined early in Pure
  3681 as Context.proof (note that ProofContext.context and Proof.context are
  3682 aliases, where the latter is the preferred name).  This enables other
  3683 Isabelle components to refer to that type even before Isar is present.
  3684 
  3685 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3686 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3687 any of these kinds.  For example, Sign.intern typeK is now
  3688 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3689 Theory.hide_types.  Also note that former
  3690 Theory.hide_classes/types/consts are now
  3691 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3692 internalize their arguments!  INCOMPATIBILITY.
  3693 
  3694 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3695 datatype thmref (with constructors Name and NameSelection) instead of
  3696 plain string -- INCOMPATIBILITY;
  3697 
  3698 * Pure: cases produced by proof methods specify options, where NONE
  3699 means to remove case bindings -- INCOMPATIBILITY in
  3700 (RAW_)METHOD_CASES.
  3701 
  3702 * Pure: the following operations retrieve axioms or theorems from a
  3703 theory node or theory hierarchy, respectively:
  3704 
  3705   Theory.axioms_of: theory -> (string * term) list
  3706   Theory.all_axioms_of: theory -> (string * term) list
  3707   PureThy.thms_of: theory -> (string * thm) list
  3708   PureThy.all_thms_of: theory -> (string * thm) list
  3709 
  3710 * Pure: print_tac now outputs the goal through the trace channel.
  3711 
  3712 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3713 Reference Toplevel.debug (default false) controls detailed printing
  3714 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3715 controls execution profiling -- set to 1 for time and 2 for space
  3716 (both increase the runtime).
  3717 
  3718 * Isar session: The initial use of ROOT.ML is now always timed,
  3719 i.e. the log will show the actual process times, in contrast to the
  3720 elapsed wall-clock time that the outer shell wrapper produces.
  3721 
  3722 * Simplifier: improved handling of bound variables (nameless
  3723 representation, avoid allocating new strings).  Simprocs that invoke
  3724 the Simplifier recursively should use Simplifier.inherit_bounds to
  3725 avoid local name clashes.  Failure to do so produces warnings
  3726 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3727 for further details.
  3728 
  3729 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3730 bindings for all theorems stored within a given theory; this may help
  3731 in porting non-Isar theories to Isar ones, while keeping ML proof
  3732 scripts for the time being.
  3733 
  3734 * ML operator HTML.with_charset specifies the charset begin used for
  3735 generated HTML files.  For example:
  3736 
  3737   HTML.with_charset "utf-8" use_thy "Hebrew";
  3738   HTML.with_charset "utf-8" use_thy "Chinese";
  3739 
  3740 
  3741 *** System ***
  3742 
  3743 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3744 isabelle, isatool etc.).
  3745 
  3746 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3747 isatool doc, isatool mkdir, display_drafts etc.).
  3748 
  3749 * isatool usedir: option -f allows specification of the ML file to be
  3750 used by Isabelle; default is ROOT.ML.
  3751 
  3752 * New isatool version outputs the version identifier of the Isabelle
  3753 distribution being used.
  3754 
  3755 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3756 (containing Boolean satisfiability problems) into Isabelle/HOL
  3757 theories.
  3758 
  3759 
  3760 
  3761 New in Isabelle2004 (April 2004)
  3762 --------------------------------
  3763 
  3764 *** General ***
  3765 
  3766 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3767   Replaces linorder.ML.
  3768 
  3769 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3770   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3771   (\<a>...\<z>), are now considered normal letters, and can therefore
  3772   be used anywhere where an ASCII letter (a...zA...Z) has until
  3773   now. COMPATIBILITY: This obviously changes the parsing of some
  3774   terms, especially where a symbol has been used as a binder, say
  3775   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3776   as an identifier.  Fix it by inserting a space around former
  3777   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3778   existing theory and ML files.
  3779 
  3780 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3781 
  3782 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3783   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3784   a normal (but invisible) letter. For multiple letter subscripts repeat
  3785   \<^isub> like this: x\<^isub>1\<^isub>2.
  3786 
  3787 * Pure: There are now sub-/superscripts that can span more than one
  3788   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3789   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3790   superscript. The new control characters are not identifier parts.
  3791 
  3792 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3793   content of "..." to the latex file instead of \isacntrl... . The "..."
  3794   may consist of any printable characters excluding the end bracket >.
  3795 
  3796 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3797   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3798   declare constants "final", which prevents their being given a definition
  3799   later.  It is useful for constants whose behaviour is fixed axiomatically
  3800   rather than definitionally, such as the meta-logic connectives.
  3801 
  3802 * Pure: 'instance' now handles general arities with general sorts
  3803   (i.e. intersections of classes),
  3804 
  3805 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3806   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3807   It can be changed to alter the colors/layout of generated pages.
  3808 
  3809 
  3810 *** Isar ***
  3811 
  3812 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3813   cut_tac, subgoal_tac and thin_tac:
  3814   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3815     locales are no longer forced to write Isar proof scripts.
  3816     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3817     emulations.
  3818   - INCOMPATIBILITY: names of variables to be instantiated may no
  3819     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3820     This is consistent with the instantiation attribute "where".
  3821 
  3822 * Attributes "where" and "of":
  3823   - Now take type variables of instantiated theorem into account when reading
  3824     the instantiation string.  This fixes a bug that caused instantiated
  3825     theorems to have too special types in some circumstances.
  3826   - "where" permits explicit instantiations of type variables.
  3827 
  3828 * Calculation commands "moreover" and "also" no longer interfere with
  3829   current facts ("this"), admitting arbitrary combinations with "then"
  3830   and derived forms.
  3831 
  3832 * Locales:
  3833   - Goal statements involving the context element "includes" no longer
  3834     generate theorems with internal delta predicates (those ending on
  3835     "_axioms") in the premise.
  3836     Resolve particular premise with <locale>.intro to obtain old form.
  3837   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3838     specification and "includes" elements in goal statement.
  3839   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3840     [intro?] and [elim?] (respectively) by default.
  3841   - Experimental command for instantiation of locales in proof contexts:
  3842         instantiate <label>[<attrs>]: <loc>
  3843     Instantiates locale <loc> and adds all its theorems to the current context
  3844     taking into account their attributes.  Label and attrs are optional
  3845     modifiers, like in theorem declarations.  If present, names of
  3846     instantiated theorems are qualified with <label>, and the attributes
  3847     <attrs> are applied after any attributes these theorems might have already.
  3848       If the locale has assumptions, a chained fact of the form
  3849     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3850     are derived.  The command does not support old-style locales declared
  3851     with "locale (open)".
  3852       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3853 
  3854 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3855   (Isar) contexts.
  3856 
  3857 
  3858 *** HOL ***
  3859 
  3860 * Proof import: new image HOL4 contains the imported library from
  3861   the HOL4 system with about 2500 theorems. It is imported by
  3862   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3863   can be used like any other Isabelle image.  See
  3864   HOL/Import/HOL/README for more information.
  3865 
  3866 * Simplifier:
  3867   - Much improved handling of linear and partial orders.
  3868     Reasoners for linear and partial orders are set up for type classes
  3869     "linorder" and "order" respectively, and are added to the default simpset
  3870     as solvers.  This means that the simplifier can build transitivity chains
  3871     to solve goals from the assumptions.
  3872   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3873     of blast or auto after simplification become unnecessary because the goal
  3874     is solved by simplification already.
  3875 
  3876 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3877     all proved in axiomatic type classes for semirings, rings and fields.
  3878 
  3879 * Numerics:
  3880   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3881     now formalized using the Ring_and_Field theory mentioned above.
  3882   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3883     than before, because now they are set up once in a generic manner.
  3884   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3885     Look for the general versions in Ring_and_Field (and Power if they concern
  3886     exponentiation).
  3887 
  3888 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3889 
  3890 * Records:
  3891   - Record types are now by default printed with their type abbreviation
  3892     instead of the list of all field types. This can be configured via
  3893     the reference "print_record_type_abbr".
  3894   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3895     (not enabled by default).
  3896   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3897     EX x. x = sel r to True (not enabled by default).
  3898   - Tactic "record_split_simp_tac" to split and simplify records added.
  3899 
  3900 * 'specification' command added, allowing for definition by
  3901   specification.  There is also an 'ax_specification' command that
  3902   introduces the new constants axiomatically.
  3903 
  3904 * arith(_tac) is now able to generate counterexamples for reals as well.
  3905 
  3906 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3907 
  3908 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3909   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3910 
  3911 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3912   matrix theory to linear programming.
  3913 
  3914 * Unions and Intersections:
  3915   The latex output syntax of UN and INT has been changed
  3916   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3917   i.e. the index formulae has become a subscript.
  3918   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3919 
  3920 * Unions and Intersections over Intervals:
  3921   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3922   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3923   like in normal math, and corresponding versions for < and for intersection.
  3924 
  3925 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3926   lexicographic dictonary ordering has been added as "lexord".
  3927 
  3928 * ML: the legacy theory structures Int and List have been removed. They had
  3929   conflicted with ML Basis Library structures having the same names.
  3930 
  3931 * 'refute' command added to search for (finite) countermodels.  Only works
  3932   for a fragment of HOL.  The installation of an external SAT solver is
  3933   highly recommended.  See "HOL/Refute.thy" for details.
  3934 
  3935 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3936   formulae under an assignment of free variables to random values.
  3937   In contrast to 'refute', it can deal with inductive datatypes,
  3938   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3939   for examples.
  3940 
  3941 
  3942 *** HOLCF ***
  3943 
  3944 * Streams now come with concatenation and are part of the HOLCF image
  3945 
  3946 
  3947 
  3948 New in Isabelle2003 (May 2003)
  3949 ------------------------------
  3950 
  3951 *** General ***
  3952 
  3953 * Provers/simplifier:
  3954 
  3955   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3956     Assumptions are now subject to complete mutual simplification,
  3957     not just from left to right. The simplifier now preserves
  3958     the order of assumptions.
  3959 
  3960     Potential INCOMPATIBILITY:
  3961 
  3962     -- simp sometimes diverges where the old version did
  3963        not, e.g. invoking simp on the goal
  3964 
  3965         [| P (f x); y = x; f x = f y |] ==> Q
  3966 
  3967        now gives rise to the infinite reduction sequence
  3968 
  3969         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3970 
  3971        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3972        kind of problem.
  3973 
  3974     -- Tactics combining classical reasoner and simplification (such as auto)
  3975        are also affected by this change, because many of them rely on
  3976        simp. They may sometimes diverge as well or yield a different numbers
  3977        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3978        in case of problems. Sometimes subsequent calls to the classical
  3979        reasoner will fail because a preceeding call to the simplifier too
  3980        eagerly simplified the goal, e.g. deleted redundant premises.
  3981 
  3982   - The simplifier trace now shows the names of the applied rewrite rules
  3983 
  3984   - You can limit the number of recursive invocations of the simplifier
  3985     during conditional rewriting (where the simplifie tries to solve the
  3986     conditions before applying the rewrite rule):
  3987     ML "simp_depth_limit := n"
  3988     where n is an integer. Thus you can force termination where previously
  3989     the simplifier would diverge.
  3990 
  3991   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  3992 
  3993   - No longer aborts on failed congruence proof.  Instead, the
  3994     congruence is ignored.
  3995 
  3996 * Pure: New generic framework for extracting programs from constructive
  3997   proofs. See HOL/Extraction.thy for an example instantiation, as well
  3998   as HOL/Extraction for some case studies.
  3999 
  4000 * Pure: The main goal of the proof state is no longer shown by default, only
  4001 the subgoals. This behaviour is controlled by a new flag.
  4002    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4003 (ML: Proof.show_main_goal).
  4004 
  4005 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4006 rules whose conclusion matches subgoal 1:
  4007       PG menu: Isabelle/Isar -> Show me -> matching rules
  4008 The rules are ordered by how closely they match the subgoal.
  4009 In particular, rules that solve a subgoal outright are displayed first
  4010 (or rather last, the way they are printed).
  4011 (ML: ProofGeneral.print_intros())
  4012 
  4013 * Pure: New flag trace_unify_fail causes unification to print
  4014 diagnostic information (PG: in trace buffer) when it fails. This is
  4015 useful for figuring out why single step proofs like rule, erule or
  4016 assumption failed.
  4017 
  4018 * Pure: Locale specifications now produce predicate definitions
  4019 according to the body of text (covering assumptions modulo local
  4020 definitions); predicate "loc_axioms" covers newly introduced text,
  4021 while "loc" is cumulative wrt. all included locale expressions; the
  4022 latter view is presented only on export into the global theory
  4023 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4024 on the old view without predicates;
  4025 
  4026 * Pure: predefined locales "var" and "struct" are useful for sharing
  4027 parameters (as in CASL, for example); just specify something like
  4028 ``var x + var y + struct M'' as import;
  4029 
  4030 * Pure: improved thms_containing: proper indexing of facts instead of
  4031 raw theorems; check validity of results wrt. current name space;
  4032 include local facts of proof configuration (also covers active
  4033 locales), cover fixed variables in index; may use "_" in term
  4034 specification; an optional limit for the number of printed facts may
  4035 be given (the default is 40);
  4036 
  4037 * Pure: disallow duplicate fact bindings within new-style theory files
  4038 (batch-mode only);
  4039 
  4040 * Provers: improved induct method: assumptions introduced by case
  4041 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4042 the goal statement); "foo" still refers to all facts collectively;
  4043 
  4044 * Provers: the function blast.overloaded has been removed: all constants
  4045 are regarded as potentially overloaded, which improves robustness in exchange
  4046 for slight decrease in efficiency;
  4047 
  4048 * Provers/linorder: New generic prover for transitivity reasoning over
  4049 linear orders.  Note: this prover is not efficient!
  4050 
  4051 * Isar: preview of problems to finish 'show' now produce an error
  4052 rather than just a warning (in interactive mode);
  4053 
  4054 
  4055 *** HOL ***
  4056 
  4057 * arith(_tac)
  4058 
  4059  - Produces a counter example if it cannot prove a goal.
  4060    Note that the counter example may be spurious if the goal is not a formula
  4061    of quantifier-free linear arithmetic.
  4062    In ProofGeneral the counter example appears in the trace buffer.
  4063 
  4064  - Knows about div k and mod k where k is a numeral of type nat or int.
  4065 
  4066  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4067    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4068    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4069 
  4070 * simp's arithmetic capabilities have been enhanced a bit: it now
  4071 takes ~= in premises into account (by performing a case split);
  4072 
  4073 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4074 are distributed over a sum of terms;
  4075 
  4076 * New tactic "trans_tac" and method "trans" instantiate
  4077 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4078 "<=", "<" and "=").
  4079 
  4080 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4081 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4082 
  4083 * 'typedef' command has new option "open" to suppress the set
  4084 definition;
  4085 
  4086 * functions Min and Max on finite sets have been introduced (theory
  4087 Finite_Set);
  4088 
  4089 * attribute [symmetric] now works for relations as well; it turns
  4090 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4091 
  4092 * induct over a !!-quantified statement (say !!x1..xn):
  4093   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4094 
  4095 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4096 %x. None. Warning: empty_def now refers to the previously hidden definition
  4097 of the empty set.
  4098 
  4099 * Algebra: formalization of classical algebra.  Intended as base for
  4100 any algebraic development in Isabelle.  Currently covers group theory
  4101 (up to Sylow's theorem) and ring theory (Universal Property of
  4102 Univariate Polynomials).  Contributions welcome;
  4103 
  4104 * GroupTheory: deleted, since its material has been moved to Algebra;
  4105 
  4106 * Complex: new directory of the complex numbers with numeric constants,
  4107 nonstandard complex numbers, and some complex analysis, standard and
  4108 nonstandard (Jacques Fleuriot);
  4109 
  4110 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4111 
  4112 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4113 Fleuriot);
  4114 
  4115 * Real/HahnBanach: updated and adapted to locales;
  4116 
  4117 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4118 Gray and Kramer);
  4119 
  4120 * UNITY: added the Meier-Sanders theory of progress sets;
  4121 
  4122 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4123 as abstract algorithms, instantiated to the JVM;
  4124 
  4125 * Bali: Java source language formalization. Type system, operational
  4126 semantics, axiomatic semantics. Supported language features:
  4127 classes, interfaces, objects,virtual methods, static methods,
  4128 static/instance fields, arrays, access modifiers, definite
  4129 assignment, exceptions.
  4130 
  4131 
  4132 *** ZF ***
  4133 
  4134 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4135 universe, etc.);
  4136 
  4137 * Main ZF: virtually all theories converted to new-style format;
  4138 
  4139 
  4140 *** ML ***
  4141 
  4142 * Pure: Tactic.prove provides sane interface for internal proofs;
  4143 omits the infamous "standard" operation, so this is more appropriate
  4144 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4145 
  4146 * Pure: improved error reporting of simprocs;
  4147 
  4148 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4149 up simprocs;
  4150 
  4151 
  4152 *** Document preparation ***
  4153 
  4154 * uses \par instead of \\ for line breaks in theory text. This may
  4155 shift some page breaks in large documents. To get the old behaviour
  4156 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4157 
  4158 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4159 other packages
  4160 
  4161 * \<euro> now needs package babel/greek instead of marvosym (which
  4162 broke \Rightarrow)
  4163 
  4164 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4165 textcomp package)
  4166 
  4167 
  4168 
  4169 New in Isabelle2002 (March 2002)
  4170 --------------------------------
  4171 
  4172 *** Document preparation ***
  4173 
  4174 * greatly simplified document preparation setup, including more
  4175 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4176 instructive isatool mkdir; users should basically be able to get
  4177 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4178 users may run a separate document processing stage manually like this:
  4179 "isatool usedir -D output HOL Test && isatool document Test/output";
  4180 
  4181 * theory dependency graph may now be incorporated into documents;
  4182 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4183 with \includegraphics of LaTeX;
  4184 
  4185 * proper spacing of consecutive markup elements, especially text
  4186 blocks after section headings;
  4187 
  4188 * support bold style (for single symbols only), input syntax is like
  4189 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4190 
  4191 * \<bullet> is now output as bold \cdot by default, which looks much
  4192 better in printed text;
  4193 
  4194 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4195 note that these symbols are currently unavailable in Proof General /
  4196 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4197 
  4198 * isatool latex no longer depends on changed TEXINPUTS, instead
  4199 isatool document copies the Isabelle style files to the target
  4200 location;
  4201 
  4202 
  4203 *** Isar ***
  4204 
  4205 * Pure/Provers: improved proof by cases and induction;
  4206   - 'case' command admits impromptu naming of parameters (such as
  4207     "case (Suc n)");
  4208   - 'induct' method divinates rule instantiation from the inductive
  4209     claim; no longer requires excessive ?P bindings for proper
  4210     instantiation of cases;
  4211   - 'induct' method properly enumerates all possibilities of set/type
  4212     rules; as a consequence facts may be also passed through *type*
  4213     rules without further ado;
  4214   - 'induct' method now derives symbolic cases from the *rulified*
  4215     rule (before it used to rulify cases stemming from the internal
  4216     atomized version); this means that the context of a non-atomic
  4217     statement becomes is included in the hypothesis, avoiding the
  4218     slightly cumbersome show "PROP ?case" form;
  4219   - 'induct' may now use elim-style induction rules without chaining
  4220     facts, using ``missing'' premises from the goal state; this allows
  4221     rules stemming from inductive sets to be applied in unstructured
  4222     scripts, while still benefitting from proper handling of non-atomic
  4223     statements; NB: major inductive premises need to be put first, all
  4224     the rest of the goal is passed through the induction;
  4225   - 'induct' proper support for mutual induction involving non-atomic
  4226     rule statements (uses the new concept of simultaneous goals, see
  4227     below);
  4228   - append all possible rule selections, but only use the first
  4229     success (no backtracking);
  4230   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4231   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4232   - added 'print_induct_rules' (covered by help item in recent Proof
  4233     General versions);
  4234   - moved induct/cases attributes to Pure, methods to Provers;
  4235   - generic method setup instantiated for FOL and HOL;
  4236 
  4237 * Pure: support multiple simultaneous goal statements, for example
  4238 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4239 meta-level mechanism, this acts as if several individual goals had
  4240 been stated separately; in particular common proof methods need to be
  4241 repeated in order to cover all claims; note that a single elimination
  4242 step is *not* sufficient to establish the two conjunctions, so this
  4243 fails:
  4244 
  4245   assume "A & B" then have A and B ..   (*".." fails*)
  4246 
  4247 better use "obtain" in situations as above; alternative refer to
  4248 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4249 
  4250 * Pure: proper integration with ``locales''; unlike the original
  4251 version by Florian Kammller, Isar locales package high-level proof
  4252 contexts rather than raw logical ones (e.g. we admit to include
  4253 attributes everywhere); operations on locales include merge and
  4254 rename; support for implicit arguments (``structures''); simultaneous
  4255 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4256 some examples;
  4257 
  4258 * Pure: the following commands have been ``localized'', supporting a
  4259 target locale specification "(in name)": 'lemma', 'theorem',
  4260 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4261 stored both within the locale and at the theory level (exported and
  4262 qualified by the locale name);
  4263 
  4264 * Pure: theory goals may now be specified in ``long'' form, with
  4265 ad-hoc contexts consisting of arbitrary locale elements. for example
  4266 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4267 definitions may be given, too); the result is a meta-level rule with
  4268 the context elements being discharged in the obvious way;
  4269 
  4270 * Pure: new proof command 'using' allows to augment currently used
  4271 facts after a goal statement ('using' is syntactically analogous to
  4272 'apply', but acts on the goal's facts only); this allows chained facts
  4273 to be separated into parts given before and after a claim, as in
  4274 ``from a and b have C using d and e <proof>'';
  4275 
  4276 * Pure: renamed "antecedent" case to "rule_context";
  4277 
  4278 * Pure: new 'judgment' command records explicit information about the
  4279 object-logic embedding (used by several tools internally); no longer
  4280 use hard-wired "Trueprop";
  4281 
  4282 * Pure: added 'corollary' command;
  4283 
  4284 * Pure: fixed 'token_translation' command;
  4285 
  4286 * Pure: removed obsolete 'exported' attribute;
  4287 
  4288 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4289 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4290 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4291 
  4292 * Pure: method 'atomize' presents local goal premises as object-level
  4293 statements (atomic meta-level propositions); setup controlled via
  4294 rewrite rules declarations of 'atomize' attribute; example
  4295 application: 'induct' method with proper rule statements in improper
  4296 proof *scripts*;
  4297 
  4298 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4299 now consider the syntactic context of assumptions, giving a better
  4300 chance to get type-inference of the arguments right (this is
  4301 especially important for locales);
  4302 
  4303 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4304 mode;
  4305 
  4306 * Pure/obtain: the formal conclusion "thesis", being marked as
  4307 ``internal'', may no longer be reference directly in the text;
  4308 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4309 situations;
  4310 
  4311 * Pure: generic 'sym' attribute which declares a rule both as pure
  4312 'elim?' and for the 'symmetric' operation;
  4313 
  4314 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4315 text; the fixed correlation with particular command syntax has been
  4316 discontinued;
  4317 
  4318 * Pure: new method 'rules' is particularly well-suited for proof
  4319 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4320 but often produces more compact proof terms with less detours;
  4321 
  4322 * Pure/Provers/classical: simplified integration with pure rule
  4323 attributes and methods; the classical "intro?/elim?/dest?"
  4324 declarations coincide with the pure ones; the "rule" method no longer
  4325 includes classically swapped intros; "intro" and "elim" methods no
  4326 longer pick rules from the context; also got rid of ML declarations
  4327 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4328 INCOMPATIBILITY;
  4329 
  4330 * Provers/classical: attribute 'swapped' produces classical inversions
  4331 of introduction rules;
  4332 
  4333 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4334 rules instead of full simplifier context; 'iff' attribute handles
  4335 conditional rules;
  4336 
  4337 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4338 
  4339 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4340 "(permissive)" option to recover old behavior;
  4341 
  4342 * HOL: 'inductive' no longer features separate (collective) attributes
  4343 for 'intros' (was found too confusing);
  4344 
  4345 * HOL: properly declared induction rules less_induct and
  4346 wf_induct_rule;
  4347 
  4348 
  4349 *** HOL ***
  4350 
  4351 * HOL: moved over to sane numeral syntax; the new policy is as
  4352 follows:
  4353 
  4354   - 0 and 1 are polymorphic constants, which are defined on any
  4355   numeric type (nat, int, real etc.);
  4356 
  4357   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4358   binary representation internally;
  4359 
  4360   - type nat has special constructor Suc, and generally prefers Suc 0
  4361   over 1::nat and Suc (Suc 0) over 2::nat;
  4362 
  4363 This change may cause significant problems of INCOMPATIBILITY; here
  4364 are some hints on converting existing sources:
  4365 
  4366   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4367   entities, so expressions involving "-" (unary or binary minus) need
  4368   to be spaced properly;
  4369 
  4370   - existing occurrences of "1" may need to be constraint "1::nat" or
  4371   even replaced by Suc 0; similar for old "2";
  4372 
  4373   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4374 
  4375   - remove all special provisions on numerals in proofs;
  4376 
  4377 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4378 representation (depends on bin_arith_simps in the default context);
  4379 
  4380 * HOL: symbolic syntax for x^2 (numeral 2);
  4381 
  4382 * HOL: the class of all HOL types is now called "type" rather than
  4383 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4384 in axclass/classes, instance/arities, and (usually rare) occurrences
  4385 in typings (of consts etc.); internally the class is called
  4386 "HOL.type", ML programs should refer to HOLogic.typeS;
  4387 
  4388 * HOL/record package improvements:
  4389   - new derived operations "fields" to build a partial record section,
  4390     "extend" to promote a fixed record to a record scheme, and
  4391     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4392     declared as simp by default;
  4393   - shared operations ("more", "fields", etc.) now need to be always
  4394     qualified) --- potential INCOMPATIBILITY;
  4395   - removed "make_scheme" operations (use "make" with "extend") --
  4396     INCOMPATIBILITY;
  4397   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4398   - provides cases/induct rules for use with corresponding Isar
  4399     methods (for concrete records, record schemes, concrete more
  4400     parts, and schematic more parts -- in that order);
  4401   - internal definitions directly based on a light-weight abstract
  4402     theory of product types over typedef rather than datatype;
  4403 
  4404 * HOL: generic code generator for generating executable ML code from
  4405 specifications; specific support for HOL constructs such as inductive
  4406 datatypes and sets, as well as recursive functions; can be invoked
  4407 via 'generate_code' theory section;
  4408 
  4409 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4410 
  4411 * HOL: consolidated and renamed several theories.  In particular:
  4412         Ord.thy has been absorbed into HOL.thy
  4413         String.thy has been absorbed into List.thy
  4414 
  4415 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4416 (beware of argument permutation!);
  4417 
  4418 * HOL: linorder_less_split superseded by linorder_cases;
  4419 
  4420 * HOL/List: "nodups" renamed to "distinct";
  4421 
  4422 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4423 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4424   - Ex_def has changed, now need to use some_eq_ex
  4425 
  4426 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4427 in this (rare) case use:
  4428 
  4429   delSWrapper "split_all_tac"
  4430   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4431 
  4432 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4433 MAY FAIL;
  4434 
  4435 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4436 Isabelle's type classes, ^ on functions and relations has too general
  4437 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4438 necessary to attach explicit type constraints;
  4439 
  4440 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4441 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4442 renamed accordingly (eg "compI" -> "rel_compI").
  4443 
  4444 * HOL: syntax translations now work properly with numerals and records
  4445 expressions;
  4446 
  4447 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4448 of "lam" -- INCOMPATIBILITY;
  4449 
  4450 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4451 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4452 renamed "Product_Type.unit";
  4453 
  4454 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4455 
  4456 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4457 the "cases" method);
  4458 
  4459 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4460 Florian Kammller);
  4461 
  4462 * HOL/IMP: updated and converted to new-style theory format; several
  4463 parts turned into readable document, with proper Isar proof texts and
  4464 some explanations (by Gerwin Klein);
  4465 
  4466 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4467 
  4468 * HOL-Hyperreal is now a logic image;
  4469 
  4470 
  4471 *** HOLCF ***
  4472 
  4473 * Isar: consts/constdefs supports mixfix syntax for continuous
  4474 operations;
  4475 
  4476 * Isar: domain package adapted to new-style theory format, e.g. see
  4477 HOLCF/ex/Dnat.thy;
  4478 
  4479 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4480 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4481 lift.induct_tac, always use UU instead of Undef;
  4482 
  4483 * HOLCF/IMP: updated and converted to new-style theory;
  4484 
  4485 
  4486 *** ZF ***
  4487 
  4488 * Isar: proper integration of logic-specific tools and packages,
  4489 including theory commands '(co)inductive', '(co)datatype',
  4490 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4491 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4492 
  4493 * theory Main no longer includes AC; for the Axiom of Choice, base
  4494 your theory on Main_ZFC;
  4495 
  4496 * the integer library now covers quotients and remainders, with many
  4497 laws relating division to addition, multiplication, etc.;
  4498 
  4499 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4500 typeless version of the formalism;
  4501 
  4502 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4503 format;
  4504 
  4505 * ZF/Induct: new directory for examples of inductive definitions,
  4506 including theory Multiset for multiset orderings; converted to
  4507 new-style theory format;
  4508 
  4509 * ZF: many new theorems about lists, ordinals, etc.;
  4510 
  4511 
  4512 *** General ***
  4513 
  4514 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4515 variable proof controls level of detail: 0 = no proofs (only oracle
  4516 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4517 also ref manual for further ML interfaces;
  4518 
  4519 * Pure/axclass: removed obsolete ML interface
  4520 goal_subclass/goal_arity;
  4521 
  4522 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4523 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4524 separate tokens, so expressions involving minus need to be spaced
  4525 properly;
  4526 
  4527 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4528 rather than "infixl" or "infixr";
  4529 
  4530 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4531 sort constraint specifications in type inference; e.g. "x::_::foo"
  4532 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4533 type variable);
  4534 
  4535 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4536 control output of nested => (types); the default behavior is
  4537 "type_brackets";
  4538 
  4539 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4540 tokens into AST constants;
  4541 
  4542 * Pure/syntax: prefer later declarations of translations and print
  4543 translation functions; potential INCOMPATIBILITY: need to reverse
  4544 multiple declarations for same syntax element constant;
  4545 
  4546 * Pure/show_hyps reset by default (in accordance to existing Isar
  4547 practice);
  4548 
  4549 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4550 addSafter;
  4551 
  4552 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4553 as well;
  4554 
  4555 * system: tested support for MacOS X; should be able to get Isabelle +
  4556 Proof General to work in a plain Terminal after installing Poly/ML
  4557 (e.g. from the Isabelle distribution area) and GNU bash alone
  4558 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4559 support requires further installations, e.g. from
  4560 http://fink.sourceforge.net/);
  4561 
  4562 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4563 
  4564 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4565 of 40 MB), cf. ML_OPTIONS;
  4566 
  4567 * system: Proof General keywords specification is now part of the
  4568 Isabelle distribution (see etc/isar-keywords.el);
  4569 
  4570 * system: support for persistent Proof General sessions (refrain from
  4571 outdating all loaded theories on startup); user may create writable
  4572 logic images like this: ``isabelle -q HOL Test'';
  4573 
  4574 * system: smart selection of Isabelle process versus Isabelle
  4575 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4576 run both "isabelle" and "Isabelle" even if file names are badly
  4577 damaged (executable inspects the case of the first letter of its own
  4578 name); added separate "isabelle-process" and "isabelle-interface";
  4579 
  4580 * system: refrain from any attempt at filtering input streams; no
  4581 longer support ``8bit'' encoding of old isabelle font, instead proper
  4582 iso-latin characters may now be used; the related isatools
  4583 "symbolinput" and "nonascii" have disappeared as well;
  4584 
  4585 * system: removed old "xterm" interface (the print modes "xterm" and
  4586 "xterm_color" are still available for direct use in a suitable
  4587 terminal);
  4588 
  4589 
  4590 
  4591 New in Isabelle99-2 (February 2001)
  4592 -----------------------------------
  4593 
  4594 *** Overview of INCOMPATIBILITIES ***
  4595 
  4596 * HOL: please note that theories in the Library and elsewhere often use the
  4597 new-style (Isar) format; to refer to their theorems in an ML script you must
  4598 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4599 
  4600 * HOL: inductive package no longer splits induction rule aggressively,
  4601 but only as far as specified by the introductions given; the old
  4602 format may be recovered via ML function complete_split_rule or attribute
  4603 'split_rule (complete)';
  4604 
  4605 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4606 gfp_Tarski to gfp_unfold;
  4607 
  4608 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4609 
  4610 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4611 relation); infix "^^" has been renamed "``"; infix "``" has been
  4612 renamed "`"; "univalent" has been renamed "single_valued";
  4613 
  4614 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4615 operation;
  4616 
  4617 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4618 
  4619 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4620 
  4621 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4622 consequence, it is no longer monotonic wrt. the local goal context
  4623 (which is now passed through the inductive cases);
  4624 
  4625 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4626 \<gg> to \<ggreater>;
  4627 
  4628 
  4629 *** Document preparation ***
  4630 
  4631 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4632 available: are "it" for near math-mode best-style output, "sl" for
  4633 slanted text style, and "tt" for plain type-writer; if no
  4634 \isabellestyle command is given, output is according to slanted
  4635 type-writer);
  4636 
  4637 * support sub/super scripts (for single symbols only), input syntax is
  4638 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4639 
  4640 * some more standard symbols; see Appendix A of the system manual for
  4641 the complete list of symbols defined in isabellesym.sty;
  4642 
  4643 * improved isabelle style files; more abstract symbol implementation
  4644 (should now use \isamath{...} and \isatext{...} in custom symbol
  4645 definitions);
  4646 
  4647 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4648 state; Note that presentation of goal states does not conform to
  4649 actual human-readable proof documents.  Please do not include goal
  4650 states into document output unless you really know what you are doing!
  4651 
  4652 * proper indentation of antiquoted output with proportional LaTeX
  4653 fonts;
  4654 
  4655 * no_document ML operator temporarily disables LaTeX document
  4656 generation;
  4657 
  4658 * isatool unsymbolize tunes sources for plain ASCII communication;
  4659 
  4660 
  4661 *** Isar ***
  4662 
  4663 * Pure: Isar now suffers initial goal statements to contain unbound
  4664 schematic variables (this does not conform to actual readable proof
  4665 documents, due to unpredictable outcome and non-compositional proof
  4666 checking); users who know what they are doing may use schematic goals
  4667 for Prolog-style synthesis of proven results;
  4668 
  4669 * Pure: assumption method (an implicit finishing) now handles actual
  4670 rules as well;
  4671 
  4672 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4673 initial goal, declare "that" only as Pure intro (only for single
  4674 steps); the "that" rule assumption may now be involved in implicit
  4675 finishing, thus ".." becomes a feasible for trivial obtains;
  4676 
  4677 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4678 instance proofs may be performed by "..";
  4679 
  4680 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4681 statements as well;
  4682 
  4683 * Pure: more robust selection of calculational rules;
  4684 
  4685 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4686 rule (as well as the assumption rule);
  4687 
  4688 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4689 lemmas, using the graph browser tool;
  4690 
  4691 * Pure: predict failure of "show" in interactive mode;
  4692 
  4693 * Pure: 'thms_containing' now takes actual terms as arguments;
  4694 
  4695 * HOL: improved method 'induct' --- now handles non-atomic goals
  4696 (potential INCOMPATIBILITY); tuned error handling;
  4697 
  4698 * HOL: cases and induct rules now provide explicit hints about the
  4699 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4700 any remaining facts are inserted into the goal verbatim;
  4701 
  4702 * HOL: local contexts (aka cases) may now contain term bindings as
  4703 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4704 the result to be shown in each case;
  4705 
  4706 * HOL: added 'recdef_tc' command;
  4707 
  4708 * isatool convert assists in eliminating legacy ML scripts;
  4709 
  4710 
  4711 *** HOL ***
  4712 
  4713 * HOL/Library: a collection of generic theories to be used together
  4714 with main HOL; the theory loader path already includes this directory
  4715 by default; the following existing theories have been moved here:
  4716 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4717 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4718 
  4719 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4720 modelling and verification task performed in Isabelle/HOL +
  4721 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4722 
  4723 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4724 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4725 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4726 'domain', this makes the theory consistent with mathematical
  4727 literature;
  4728 
  4729 * HOL basics: added overloaded operations "inverse" and "divide"
  4730 (infix "/"), syntax for generic "abs" operation, generic summation
  4731 operator \<Sum>;
  4732 
  4733 * HOL/typedef: simplified package, provide more useful rules (see also
  4734 HOL/subset.thy);
  4735 
  4736 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4737 now expressed as a proper nested rule (old-style tactic scripts may
  4738 require atomize_strip_tac to cope with non-atomic premises);
  4739 
  4740 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4741 to "split_conv" (old name still available for compatibility);
  4742 
  4743 * HOL: improved concrete syntax for strings (e.g. allows translation
  4744 rules with string literals);
  4745 
  4746 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4747  and Fleuriot's mechanization of analysis, including the transcendental
  4748  functions for the reals;
  4749 
  4750 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4751 
  4752 
  4753 *** CTT ***
  4754 
  4755 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4756 "lam" is displayed as TWO lambda-symbols
  4757 
  4758 * CTT: theory Main now available, containing everything (that is, Bool
  4759 and Arith);
  4760 
  4761 
  4762 *** General ***
  4763 
  4764 * Pure: the Simplifier has been implemented properly as a derived rule
  4765 outside of the actual kernel (at last!); the overall performance
  4766 penalty in practical applications is about 50%, while reliability of
  4767 the Isabelle inference kernel has been greatly improved;
  4768 
  4769 * print modes "brackets" and "no_brackets" control output of nested =>
  4770 (types) and ==> (props); the default behaviour is "brackets";
  4771 
  4772 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4773 as assumptions as well;
  4774 
  4775 * system: support Poly/ML 4.0;
  4776 
  4777 * system: isatool install handles KDE version 1 or 2;
  4778 
  4779 
  4780 
  4781 New in Isabelle99-1 (October 2000)
  4782 ----------------------------------
  4783 
  4784 *** Overview of INCOMPATIBILITIES ***
  4785 
  4786 * HOL: simplification of natural numbers is much changed; to partly
  4787 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4788 issue the following ML commands:
  4789 
  4790   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4791   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4792 
  4793 * HOL: simplification no longer dives into case-expressions; this is
  4794 controlled by "t.weak_case_cong" for each datatype t;
  4795 
  4796 * HOL: nat_less_induct renamed to less_induct;
  4797 
  4798 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4799 fixsome to patch .thy and .ML sources automatically;
  4800 
  4801   select_equality  -> some_equality
  4802   select_eq_Ex     -> some_eq_ex
  4803   selectI2EX       -> someI2_ex
  4804   selectI2         -> someI2
  4805   selectI          -> someI
  4806   select1_equality -> some1_equality
  4807   Eps_sym_eq       -> some_sym_eq_trivial
  4808   Eps_eq           -> some_eq_trivial
  4809 
  4810 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4811 
  4812 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4813 instead);
  4814 
  4815 * HOL: the recursion equations generated by 'recdef' are now called
  4816 f.simps instead of f.rules;
  4817 
  4818 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4819 
  4820 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4821 sometimes be needed;
  4822 
  4823 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4824 
  4825 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4826 
  4827 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4828 product is now "<*>" instead of "Times"; the lexicographic product is
  4829 now "<*lex*>" instead of "**";
  4830 
  4831 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4832 of main HOL, but was unused); better use HOL's datatype package;
  4833 
  4834 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4835 the old syntax may be recovered as follows:
  4836 
  4837   syntax (symbols)
  4838     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4839       (infixl "\\<oplus>" 100)
  4840 
  4841 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4842 
  4843 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4844 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4845 internally;
  4846 
  4847 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4848 changed from A/r to A//r;
  4849 
  4850 * ZF: new treatment of arithmetic (nat & int) may break some old
  4851 proofs;
  4852 
  4853 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4854 rulify -> rule_format, elimify -> elim_format, ...);
  4855 
  4856 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4857 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4858 should have to change intro!! to intro? only); replaced "delrule" by
  4859 "rule del";
  4860 
  4861 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4862 
  4863 * Provers: strengthened force_tac by using new first_best_tac;
  4864 
  4865 * LaTeX document preparation: several changes of isabelle.sty (see
  4866 lib/texinputs);
  4867 
  4868 
  4869 *** Document preparation ***
  4870 
  4871 * formal comments (text blocks etc.) in new-style theories may now
  4872 contain antiquotations of thm/prop/term/typ/text to be presented
  4873 according to latex print mode; concrete syntax is like this:
  4874 @{term[show_types] "f(x) = a + x"};
  4875 
  4876 * isatool mkdir provides easy setup of Isabelle session directories,
  4877 including proper document sources;
  4878 
  4879 * generated LaTeX sources are now deleted after successful run
  4880 (isatool document -c); may retain a copy somewhere else via -D option
  4881 of isatool usedir;
  4882 
  4883 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4884 style files, achieving self-contained LaTeX sources and simplifying
  4885 LaTeX debugging;
  4886 
  4887 * old-style theories now produce (crude) LaTeX output as well;
  4888 
  4889 * browser info session directories are now self-contained (may be put
  4890 on WWW server seperately); improved graphs of nested sessions; removed
  4891 graph for 'all sessions';
  4892 
  4893 * several improvements in isabelle style files; \isabellestyle{it}
  4894 produces fake math mode output; \isamarkupheader is now \section by
  4895 default; see lib/texinputs/isabelle.sty etc.;
  4896 
  4897 
  4898 *** Isar ***
  4899 
  4900 * Isar/Pure: local results and corresponding term bindings are now
  4901 subject to Hindley-Milner polymorphism (similar to ML); this
  4902 accommodates incremental type-inference very nicely;
  4903 
  4904 * Isar/Pure: new derived language element 'obtain' supports
  4905 generalized existence reasoning;
  4906 
  4907 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4908 support accumulation of results, without applying any rules yet;
  4909 useful to collect intermediate results without explicit name
  4910 references, and for use with transitivity rules with more than 2
  4911 premises;
  4912 
  4913 * Isar/Pure: scalable support for case-analysis type proofs: new
  4914 'case' language element refers to local contexts symbolically, as
  4915 produced by certain proof methods; internally, case names are attached
  4916 to theorems as "tags";
  4917 
  4918 * Isar/Pure: theory command 'hide' removes declarations from
  4919 class/type/const name spaces;
  4920 
  4921 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4922 indicate potential overloading;
  4923 
  4924 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4925 
  4926 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4927 "{a,b,c}" instead of {a,b,c};
  4928 
  4929 * Isar/Pure now provides its own version of intro/elim/dest
  4930 attributes; useful for building new logics, but beware of confusion
  4931 with the version in Provers/classical;
  4932 
  4933 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4934 case name 'antecedent';
  4935 
  4936 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4937 to the current context is now done automatically);
  4938 
  4939 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4940 for definining proof methods in ML;
  4941 
  4942 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4943 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4944 most cases, one should have to change intro!! to intro? only);
  4945 replaced "delrule" by "rule del";
  4946 
  4947 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4948 'symmetric' attribute (the latter supercedes [RS sym]);
  4949 
  4950 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4951 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4952 well (including splits);
  4953 
  4954 * Isar/Provers: Simplifier and Classical methods now support all kind
  4955 of modifiers used in the past, including 'cong', 'iff', etc.
  4956 
  4957 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4958 of Simplifier and Classical reasoner);
  4959 
  4960 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4961 now support named cases; major packages (inductive, datatype, primrec,
  4962 recdef) support case names and properly name parameters;
  4963 
  4964 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4965 monotonicity conditions are extracted to be proven at end of
  4966 calculations;
  4967 
  4968 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4969 method anyway;
  4970 
  4971 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4972 split_if split_if_asm; datatype package provides theorems foo.splits =
  4973 foo.split foo.split_asm for each datatype;
  4974 
  4975 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4976 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4977 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4978 use "(cases (simplified))" method in proper proof texts);
  4979 
  4980 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4981 
  4982 * Isar: names of theorems etc. may be natural numbers as well;
  4983 
  4984 * Isar: 'pr' command: optional arguments for goals_limit and
  4985 ProofContext.prems_limit; no longer prints theory contexts, but only
  4986 proof states;
  4987 
  4988 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4989 additional print modes to be specified; e.g. "pr(latex)" will print
  4990 proof state according to the Isabelle LaTeX style;
  4991 
  4992 * Isar: improved support for emulating tactic scripts, including proof
  4993 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  4994 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  4995 (for HOL datatypes);
  4996 
  4997 * Isar: simplified (more robust) goal selection of proof methods: 1st
  4998 goal, all goals, or explicit goal specifier (tactic emulation); thus
  4999 'proof method scripts' have to be in depth-first order;
  5000 
  5001 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5002 
  5003 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5004 should instead use individual commands for printing items
  5005 (print_commands, print_methods etc.);
  5006 
  5007 * Isar: added 'nothing' --- the empty list of theorems;
  5008 
  5009 
  5010 *** HOL ***
  5011 
  5012 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5013 corresponding virtual machine and a specification of its bytecode
  5014 verifier and a lightweight bytecode verifier, including proofs of
  5015 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5016 Cornelia Pusch (see also the homepage of project Bali at
  5017 http://isabelle.in.tum.de/Bali/);
  5018 
  5019 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5020 Clemens Ballarin;
  5021 
  5022 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5023 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5024 Rasmussen;
  5025 
  5026 * HOL/Lattice: fundamental concepts of lattice theory and order
  5027 structures, including duals, properties of bounds versus algebraic
  5028 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5029 Theorem for complete lattices etc.; may also serve as a demonstration
  5030 for abstract algebraic reasoning using axiomatic type classes, and
  5031 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5032 
  5033 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5034 von Oheimb;
  5035 
  5036 * HOL/IMPP: extension of IMP with local variables and mutually
  5037 recursive procedures, by David von Oheimb;
  5038 
  5039 * HOL/Lambda: converted into new-style theory and document;
  5040 
  5041 * HOL/ex/Multiquote: example of multiple nested quotations and
  5042 anti-quotations -- basically a generalized version of de-Bruijn
  5043 representation; very useful in avoiding lifting of operations;
  5044 
  5045 * HOL/record: added general record equality rule to simpset; fixed
  5046 select-update simplification procedure to handle extended records as
  5047 well; admit "r" as field name;
  5048 
  5049 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5050 other numeric types and also as the identity of groups, rings, etc.;
  5051 
  5052 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5053 Types nat and int belong to this axclass;
  5054 
  5055 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5056    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5057    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5058   two terms #m*u and #n*u are replaced by #(m+n)*u
  5059     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5060   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5061     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5062 
  5063 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5064 powerful prover for predicate logic but knows nothing of clasets; see
  5065 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5066 
  5067 * HOL: new version of "case_tac" subsumes both boolean case split and
  5068 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5069 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5070 
  5071 * HOL: simplification no longer dives into case-expressions: only the
  5072 selector expression is simplified, but not the remaining arms; to
  5073 enable full simplification of case-expressions for datatype t, you may
  5074 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5075 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5076 
  5077 * HOL/recdef: the recursion equations generated by 'recdef' for
  5078 function 'f' are now called f.simps instead of f.rules; if all
  5079 termination conditions are proved automatically, these simplification
  5080 rules are added to the simpset, as in primrec; rules may be named
  5081 individually as well, resulting in a separate list of theorems for
  5082 each equation;
  5083 
  5084 * HOL/While is a new theory that provides a while-combinator. It
  5085 permits the definition of tail-recursive functions without the
  5086 provision of a termination measure. The latter is necessary once the
  5087 invariant proof rule for while is applied.
  5088 
  5089 * HOL: new (overloaded) notation for the set of elements below/above
  5090 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5091 
  5092 * HOL: theorems impI, allI, ballI bound as "strip";
  5093 
  5094 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5095 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5096 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5097 
  5098 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5099 
  5100 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5101 main HOL, but was unused);
  5102 
  5103 * HOL: fewer consts declared as global (e.g. have to refer to
  5104 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5105 
  5106 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5107 in case of overlap with user translations (e.g. judgements over
  5108 tuples); (note that the underlying logical represenation is still
  5109 bogus);
  5110 
  5111 
  5112 *** ZF ***
  5113 
  5114 * ZF: simplification automatically cancels common terms in arithmetic
  5115 expressions over nat and int;
  5116 
  5117 * ZF: new treatment of nat to minimize type-checking: all operators
  5118 coerce their operands to a natural number using the function natify,
  5119 making the algebraic laws unconditional;
  5120 
  5121 * ZF: as above, for int: operators coerce their operands to an integer
  5122 using the function intify;
  5123 
  5124 * ZF: the integer library now contains many of the usual laws for the
  5125 orderings, including $<=, and monotonicity laws for $+ and $*;
  5126 
  5127 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5128 simplification;
  5129 
  5130 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5131 to the simplifier and classical reasoner simultaneously;
  5132 
  5133 
  5134 *** General ***
  5135 
  5136 * Provers: blast_tac now handles actual object-logic rules as
  5137 assumptions; note that auto_tac uses blast_tac internally as well;
  5138 
  5139 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5140 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5141 
  5142 * Provers: delrules now handles destruct rules as well (no longer need
  5143 explicit make_elim);
  5144 
  5145 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5146   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5147 use instead the strong form,
  5148   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5149 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5150 from destruct-rules;
  5151 
  5152 * Provers: Simplifier.easy_setup provides a fast path to basic
  5153 Simplifier setup for new object-logics;
  5154 
  5155 * Pure: AST translation rules no longer require constant head on LHS;
  5156 
  5157 * Pure: improved name spaces: ambiguous output is qualified; support
  5158 for hiding of names;
  5159 
  5160 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5161 XSYMBOL_HOME; no longer need to do manual configuration in most
  5162 situations;
  5163 
  5164 * system: compression of ML heaps images may now be controlled via -c
  5165 option of isabelle and isatool usedir (currently only observed by
  5166 Poly/ML);
  5167 
  5168 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5169 useful for remote X11);
  5170 
  5171 * system: provide TAGS file for Isabelle sources;
  5172 
  5173 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5174 order;
  5175 
  5176 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5177 timing flag supersedes proof_timing and Toplevel.trace;
  5178 
  5179 * ML: new combinators |>> and |>>> for incremental transformations
  5180 with secondary results (e.g. certain theory extensions):
  5181 
  5182 * ML: PureThy.add_defs gets additional argument to indicate potential
  5183 overloading (usually false);
  5184 
  5185 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5186 results;
  5187 
  5188 
  5189 
  5190 New in Isabelle99 (October 1999)
  5191 --------------------------------
  5192 
  5193 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5194 
  5195 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5196 are no longer simplified.  (This allows the simplifier to unfold recursive
  5197 functional programs.)  To restore the old behaviour, declare
  5198 
  5199     Delcongs [if_weak_cong];
  5200 
  5201 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5202 complement;
  5203 
  5204 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5205 
  5206 * HOL/datatype: mutual_induct_tac no longer exists --
  5207   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5208 
  5209 * HOL/typedef: fixed type inference for representing set; type
  5210 arguments now have to occur explicitly on the rhs as type constraints;
  5211 
  5212 * ZF: The con_defs part of an inductive definition may no longer refer
  5213 to constants declared in the same theory;
  5214 
  5215 * HOL, ZF: the function mk_cases, generated by the inductive
  5216 definition package, has lost an argument.  To simplify its result, it
  5217 uses the default simpset instead of a supplied list of theorems.
  5218 
  5219 * HOL/List: the constructors of type list are now Nil and Cons;
  5220 
  5221 * Simplifier: the type of the infix ML functions
  5222         setSSolver addSSolver setSolver addSolver
  5223 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5224 for packaging solvers. A solver is created via
  5225         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5226 where the string argument is only a comment.
  5227 
  5228 
  5229 *** Proof tools ***
  5230 
  5231 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5232 decision procedure for linear arithmetic. Currently it is used for
  5233 types `nat', `int', and `real' in HOL (see below); it can, should and
  5234 will be instantiated for other types and logics as well.
  5235 
  5236 * The simplifier now accepts rewrite rules with flexible heads, eg
  5237      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5238   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5239   matching.
  5240 
  5241 
  5242 *** General ***
  5243 
  5244 * New Isabelle/Isar subsystem provides an alternative to traditional
  5245 tactical theorem proving; together with the ProofGeneral/isar user
  5246 interface it offers an interactive environment for developing human
  5247 readable proof documents (Isar == Intelligible semi-automated
  5248 reasoning); for further information see isatool doc isar-ref,
  5249 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5250 
  5251 * improved and simplified presentation of theories: better HTML markup
  5252 (including colors), graph views in several sizes; isatool usedir now
  5253 provides a proper interface for user theories (via -P option); actual
  5254 document preparation based on (PDF)LaTeX is available as well (for
  5255 new-style theories only); see isatool doc system for more information;
  5256 
  5257 * native support for Proof General, both for classic Isabelle and
  5258 Isabelle/Isar;
  5259 
  5260 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5261 using the graph browser tool;
  5262 
  5263 * Isabelle manuals now also available as PDF;
  5264 
  5265 * theory loader rewritten from scratch (may not be fully
  5266 bug-compatible); old loadpath variable has been replaced by show_path,
  5267 add_path, del_path, reset_path functions; new operations such as
  5268 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5269 isatool doc ref);
  5270 
  5271 * improved isatool install: option -k creates KDE application icon,
  5272 option -p DIR installs standalone binaries;
  5273 
  5274 * added ML_PLATFORM setting (useful for cross-platform installations);
  5275 more robust handling of platform specific ML images for SML/NJ;
  5276 
  5277 * the settings environment is now statically scoped, i.e. it is never
  5278 created again in sub-processes invoked from isabelle, isatool, or
  5279 Isabelle;
  5280 
  5281 * path element specification '~~' refers to '$ISABELLE_HOME';
  5282 
  5283 * in locales, the "assumes" and "defines" parts may be omitted if
  5284 empty;
  5285 
  5286 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5287 long arrows);
  5288 
  5289 * new print_mode "HTML";
  5290 
  5291 * new flag show_tags controls display of tags of theorems (which are
  5292 basically just comments that may be attached by some tools);
  5293 
  5294 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5295 mode and goal output format:
  5296 
  5297 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5298 244c244
  5299 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5300 ---
  5301 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5302 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5303 181c181
  5304 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5305 ---
  5306 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5307 
  5308 * function bind_thms stores lists of theorems (cf. bind_thm);
  5309 
  5310 * new shorthand tactics ftac, eatac, datac, fatac;
  5311 
  5312 * qed (and friends) now accept "" as result name; in that case the
  5313 theorem is not stored, but proper checks and presentation of the
  5314 result still apply;
  5315 
  5316 * theorem database now also indexes constants "Trueprop", "all",
  5317 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5318 
  5319 
  5320 *** HOL ***
  5321 
  5322 ** HOL arithmetic **
  5323 
  5324 * There are now decision procedures for linear arithmetic over nat and
  5325 int:
  5326 
  5327 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5328 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5329 are treated as atomic; subformulae not involving type `nat' or `int'
  5330 are ignored; quantified subformulae are ignored unless they are
  5331 positive universal or negative existential. The tactic has to be
  5332 invoked by hand and can be a little bit slow. In particular, the
  5333 running time is exponential in the number of occurrences of `min' and
  5334 `max', and `-' on `nat'.
  5335 
  5336 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5337 (negated) (in)equalities among the premises and the conclusion into
  5338 account (i.e. no compound formulae) and does not know about `min' and
  5339 `max', and `-' on `nat'. It is fast and is used automatically by the
  5340 simplifier.
  5341 
  5342 NB: At the moment, these decision procedures do not cope with mixed
  5343 nat/int formulae where the two parts interact, such as `m < n ==>
  5344 int(m) < int(n)'.
  5345 
  5346 * HOL/Numeral provides a generic theory of numerals (encoded
  5347 efficiently as bit strings); setup for types nat/int/real is in place;
  5348 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5349 int, existing theories and proof scripts may require a few additional
  5350 type constraints;
  5351 
  5352 * integer division and remainder can now be performed on constant
  5353 arguments;
  5354 
  5355 * many properties of integer multiplication, division and remainder
  5356 are now available;
  5357 
  5358 * An interface to the Stanford Validity Checker (SVC) is available through the
  5359 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5360 are proved automatically.  SVC must be installed separately, and its results
  5361 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5362 invocation of the underlying oracle).  For SVC see
  5363   http://verify.stanford.edu/SVC
  5364 
  5365 * IsaMakefile: the HOL-Real target now builds an actual image;
  5366 
  5367 
  5368 ** HOL misc **
  5369 
  5370 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5371 (in Isabelle/Isar) -- by Gertrud Bauer;
  5372 
  5373 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5374 analysis for assembly languages with subtypes;
  5375 
  5376 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5377 -- avoids syntactic ambiguities and treats state, transition, and
  5378 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5379 changed syntax and (many) tactics;
  5380 
  5381 * HOL/inductive: Now also handles more general introduction rules such
  5382   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5383   theorems are now maintained within the theory (maintained via the
  5384   "mono" attribute);
  5385 
  5386 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5387   (using function types) such as
  5388 
  5389   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5390 
  5391 * HOL/record: record_simproc (part of the default simpset) takes care
  5392 of selectors applied to updated records; record_split_tac is no longer
  5393 part of the default claset; update_defs may now be removed from the
  5394 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5395 
  5396   claset_ref () := claset() addSWrapper record_split_wrapper;
  5397   Delsimprocs [record_simproc]
  5398 
  5399 * HOL/typedef: fixed type inference for representing set; type
  5400 arguments now have to occur explicitly on the rhs as type constraints;
  5401 
  5402 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5403 names rather than an ML expression;
  5404 
  5405 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5406 supplied later.  Program schemes can be defined, such as
  5407     "While B C s = (if B s then While B C (C s) else s)"
  5408 where the well-founded relation can be chosen after B and C have been given.
  5409 
  5410 * HOL/List: the constructors of type list are now Nil and Cons;
  5411 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5412 course, ML tools referring to List.list.op # etc. have to be adapted;
  5413 
  5414 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5415 disabled by default; run isabelle with option -m HOL to get back to
  5416 the original Gordon/HOL-style output;
  5417 
  5418 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5419 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5420 
  5421 * HOL basic syntax simplified (more orthogonal): all variants of
  5422 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5423 Eps operator is provided as well: "SOME x. P[x]";
  5424 
  5425 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5426 
  5427 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5428 thus available for user theories;
  5429 
  5430 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5431 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5432 time;
  5433 
  5434 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5435 several times and then mp;
  5436 
  5437 
  5438 *** LK ***
  5439 
  5440 * the notation <<...>> is now available as a notation for sequences of
  5441 formulas;
  5442 
  5443 * the simplifier is now installed
  5444 
  5445 * the axiom system has been generalized (thanks to Soren Heilmann)
  5446 
  5447 * the classical reasoner now has a default rule database
  5448 
  5449 
  5450 *** ZF ***
  5451 
  5452 * new primrec section allows primitive recursive functions to be given
  5453 directly (as in HOL) over datatypes and the natural numbers;
  5454 
  5455 * new tactics induct_tac and exhaust_tac for induction (or case
  5456 analysis) over datatypes and the natural numbers;
  5457 
  5458 * the datatype declaration of type T now defines the recursor T_rec;
  5459 
  5460 * simplification automatically does freeness reasoning for datatype
  5461 constructors;
  5462 
  5463 * automatic type-inference, with AddTCs command to insert new
  5464 type-checking rules;
  5465 
  5466 * datatype introduction rules are now added as Safe Introduction rules
  5467 to the claset;
  5468 
  5469 * the syntax "if P then x else y" is now available in addition to
  5470 if(P,x,y);
  5471 
  5472 
  5473 *** Internal programming interfaces ***
  5474 
  5475 * tuned simplifier trace output; new flag debug_simp;
  5476 
  5477 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5478 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5479 
  5480 * AxClass.axclass_tac lost the theory argument;
  5481 
  5482 * tuned current_goals_markers semantics: begin / end goal avoids
  5483 printing empty lines;
  5484 
  5485 * removed prs and prs_fn hook, which was broken because it did not
  5486 include \n in its semantics, forcing writeln to add one
  5487 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5488 string -> unit if you really want to output text without newline;
  5489 
  5490 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5491 plain output, interface builders may have to enable 'isabelle_font'
  5492 mode to get Isabelle font glyphs as before;
  5493 
  5494 * refined token_translation interface; INCOMPATIBILITY: output length
  5495 now of type real instead of int;
  5496 
  5497 * theory loader actions may be traced via new ThyInfo.add_hook
  5498 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5499 your own database of information attached to *whole* theories -- as
  5500 opposed to intra-theory data slots offered via TheoryDataFun;
  5501 
  5502 * proper handling of dangling sort hypotheses (at last!);
  5503 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5504 extra sort hypotheses that can be witnessed from the type signature;
  5505 the force_strip_shyps flag is gone, any remaining shyps are simply
  5506 left in the theorem (with a warning issued by strip_shyps_warning);
  5507 
  5508 
  5509 
  5510 New in Isabelle98-1 (October 1998)
  5511 ----------------------------------
  5512 
  5513 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5514 
  5515 * several changes of automated proof tools;
  5516 
  5517 * HOL: major changes to the inductive and datatype packages, including
  5518 some minor incompatibilities of theory syntax;
  5519 
  5520 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5521 called `inj_on';
  5522 
  5523 * HOL: removed duplicate thms in Arith:
  5524   less_imp_add_less  should be replaced by  trans_less_add1
  5525   le_imp_add_le      should be replaced by  trans_le_add1
  5526 
  5527 * HOL: unary minus is now overloaded (new type constraints may be
  5528 required);
  5529 
  5530 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5531 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5532 now taken as an integer constant.
  5533 
  5534 * Pure: ML function 'theory_of' renamed to 'theory';
  5535 
  5536 
  5537 *** Proof tools ***
  5538 
  5539 * Simplifier:
  5540   1. Asm_full_simp_tac is now more aggressive.
  5541      1. It will sometimes reorient premises if that increases their power to
  5542         simplify.
  5543      2. It does no longer proceed strictly from left to right but may also
  5544         rotate premises to achieve further simplification.
  5545      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5546      old Asm_full_simp_tac in that it does not rotate premises.
  5547   2. The simplifier now knows a little bit about nat-arithmetic.
  5548 
  5549 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5550 allows for selected deletion of wrappers, by introduction of names for
  5551 wrapper functionals.  This implies that addbefore, addSbefore,
  5552 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5553 and that adding two tactics with the same name overwrites the first
  5554 one (emitting a warning).
  5555   type wrapper = (int -> tactic) -> (int -> tactic)
  5556   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5557   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5558   delWrapper, delSWrapper: claset *  string            -> claset
  5559   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5560 
  5561 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5562 semantics; addbefore now affects only the unsafe part of step_tac
  5563 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5564 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5565 by Force_tac;
  5566 
  5567 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5568 compWrapper; added safe wrapper (and access functions for it);
  5569 
  5570 * HOL/split_all_tac is now much faster and fails if there is nothing
  5571 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5572 and the names of the automatically generated variables have changed.
  5573 split_all_tac has moved within claset() from unsafe wrappers to safe
  5574 wrappers, which means that !!-bound variables are split much more
  5575 aggressively, and safe_tac and clarify_tac now split such variables.
  5576 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5577 Note: the same holds for record_split_tac, which does the job of
  5578 split_all_tac for record fields.
  5579 
  5580 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5581 permanently to the default simpset using Addsplits just like
  5582 Addsimps. They can be removed via Delsplits just like
  5583 Delsimps. Lower-case versions are also available.
  5584 
  5585 * HOL/Simplifier: The rule split_if is now part of the default
  5586 simpset. This means that the simplifier will eliminate all occurrences
  5587 of if-then-else in the conclusion of a goal. To prevent this, you can
  5588 either remove split_if completely from the default simpset by
  5589 `Delsplits [split_if]' or remove it in a specific call of the
  5590 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5591 other case splitting rules to/from the default simpset: every datatype
  5592 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5593 t is the name of the datatype).
  5594 
  5595 * Classical reasoner / Simplifier combination: new force_tac (and
  5596 derivatives Force_tac, force) combines rewriting and classical
  5597 reasoning (and whatever other tools) similarly to auto_tac, but is
  5598 aimed to solve the given subgoal completely.
  5599 
  5600 
  5601 *** General ***
  5602 
  5603 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5604 and `goalw': the theory is no longer needed as an explicit argument -
  5605 the current theory context is used; assumptions are no longer returned
  5606 at the ML-level unless one of them starts with ==> or !!; it is
  5607 recommended to convert to these new commands using isatool fixgoal
  5608 (backup your sources first!);
  5609 
  5610 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5611 the current theory context, and 'theory' to lookup stored theories;
  5612 
  5613 * new theory section 'locale' for declaring constants, assumptions and
  5614 definitions that have local scope;
  5615 
  5616 * new theory section 'nonterminals' for purely syntactic types;
  5617 
  5618 * new theory section 'setup' for generic ML setup functions
  5619 (e.g. package initialization);
  5620 
  5621 * the distribution now includes Isabelle icons: see
  5622 lib/logo/isabelle-{small,tiny}.xpm;
  5623 
  5624 * isatool install - install binaries with absolute references to
  5625 ISABELLE_HOME/bin;
  5626 
  5627 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5628 
  5629 * print mode 'emacs' reserved for Isamode;
  5630 
  5631 * support multiple print (ast) translations per constant name;
  5632 
  5633 * theorems involving oracles are now printed with a suffixed [!];
  5634 
  5635 
  5636 *** HOL ***
  5637 
  5638 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5639 
  5640 * HOL/inductive package reorganized and improved: now supports mutual
  5641 definitions such as
  5642 
  5643   inductive EVEN ODD
  5644     intrs
  5645       null "0 : EVEN"
  5646       oddI "n : EVEN ==> Suc n : ODD"
  5647       evenI "n : ODD ==> Suc n : EVEN"
  5648 
  5649 new theorem list "elims" contains an elimination rule for each of the
  5650 recursive sets; inductive definitions now handle disjunctive premises
  5651 correctly (also ZF);
  5652 
  5653 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5654 "mutual_induct" no longer exists - the induction rule is always
  5655 contained in "induct";
  5656 
  5657 
  5658 * HOL/datatype package re-implemented and greatly improved: now
  5659 supports mutually recursive datatypes such as
  5660 
  5661   datatype
  5662     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5663             | SUM ('a aexp) ('a aexp)
  5664             | DIFF ('a aexp) ('a aexp)
  5665             | NUM 'a
  5666   and
  5667     'a bexp = LESS ('a aexp) ('a aexp)
  5668             | AND ('a bexp) ('a bexp)
  5669             | OR ('a bexp) ('a bexp)
  5670 
  5671 as well as indirectly recursive datatypes such as
  5672 
  5673   datatype
  5674     ('a, 'b) term = Var 'a
  5675                   | App 'b ((('a, 'b) term) list)
  5676 
  5677 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5678 induction on mutually / indirectly recursive datatypes.
  5679 
  5680 Primrec equations are now stored in theory and can be accessed via
  5681 <function_name>.simps.
  5682 
  5683 INCOMPATIBILITIES:
  5684 
  5685   - Theories using datatypes must now have theory Datatype as an
  5686     ancestor.
  5687   - The specific <typename>.induct_tac no longer exists - use the
  5688     generic induct_tac instead.
  5689   - natE has been renamed to nat.exhaust - use exhaust_tac
  5690     instead of res_inst_tac ... natE. Note that the variable
  5691     names in nat.exhaust differ from the names in natE, this
  5692     may cause some "fragile" proofs to fail.
  5693   - The theorems split_<typename>_case and split_<typename>_case_asm
  5694     have been renamed to <typename>.split and <typename>.split_asm.
  5695   - Since default sorts of type variables are now handled correctly,
  5696     some datatype definitions may have to be annotated with explicit
  5697     sort constraints.
  5698   - Primrec definitions no longer require function name and type
  5699     of recursive argument.
  5700 
  5701 Consider using isatool fixdatatype to adapt your theories and proof
  5702 scripts to the new package (backup your sources first!).
  5703 
  5704 
  5705 * HOL/record package: considerably improved implementation; now
  5706 includes concrete syntax for record types, terms, updates; theorems
  5707 for surjective pairing and splitting !!-bound record variables; proof
  5708 support is as follows:
  5709 
  5710   1) standard conversions (selectors or updates applied to record
  5711 constructor terms) are part of the standard simpset;
  5712 
  5713   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5714 made part of standard simpset and claset via addIffs;
  5715 
  5716   3) a tactic for record field splitting (record_split_tac) is part of
  5717 the standard claset (addSWrapper);
  5718 
  5719 To get a better idea about these rules you may retrieve them via
  5720 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5721 the name of your record type.
  5722 
  5723 The split tactic 3) conceptually simplifies by the following rule:
  5724 
  5725   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5726 
  5727 Thus any record variable that is bound by meta-all will automatically
  5728 blow up into some record constructor term, consequently the
  5729 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5730 solve record problems automatically.
  5731 
  5732 
  5733 * reorganized the main HOL image: HOL/Integ and String loaded by
  5734 default; theory Main includes everything;
  5735 
  5736 * automatic simplification of integer sums and comparisons, using cancellation;
  5737 
  5738 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5739 
  5740 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5741 
  5742 * many new identities for unions, intersections, set difference, etc.;
  5743 
  5744 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5745 called split_if, split_split, split_sum_case and split_nat_case (to go
  5746 with add/delsplits);
  5747 
  5748 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5749 (?x::unit) = (); this is made part of the default simpset, which COULD
  5750 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5751 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5752 unit_abs_eta_conv is added in order to counter the effect of
  5753 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5754 %u.f();
  5755 
  5756 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5757 makes more sense);
  5758 
  5759 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5760   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5761   disjointness reasoning but breaking a few old proofs.
  5762 
  5763 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5764 to 'converse' from 'inverse' (for compatibility with ZF and some
  5765 literature);
  5766 
  5767 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5768 the well-founded relation;
  5769 
  5770 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5771     Compl A.  The "Compl" syntax remains available as input syntax for this
  5772     release ONLY.
  5773 
  5774 * HOL/Update: new theory of function updates:
  5775     f(a:=b) == %x. if x=a then b else f x
  5776 may also be iterated as in f(a:=b,c:=d,...);
  5777 
  5778 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5779 
  5780 * HOL/List:
  5781   - new function list_update written xs[i:=v] that updates the i-th
  5782     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5783   - new function `upt' written [i..j(] which generates the list
  5784     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5785     bound write [i..j], which is a shorthand for [i..j+1(].
  5786   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5787 
  5788 * HOL/Arith:
  5789   - removed 'pred' (predecessor) function;
  5790   - generalized some theorems about n-1;
  5791   - many new laws about "div" and "mod";
  5792   - new laws about greatest common divisors (see theory ex/Primes);
  5793 
  5794 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5795 instead of "inverse";
  5796 
  5797 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5798   of the multiset ordering;
  5799 
  5800 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5801   (not included by default);
  5802 
  5803 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5804 
  5805 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5806   programs, i.e. different program variables may have different types.
  5807 
  5808 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5809   [previously, this check worked only if the rewrite rule was unconditional]
  5810   Now rew can involve either definitions or equalities (either == or =).
  5811 
  5812 
  5813 *** ZF ***
  5814 
  5815 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5816   only the theorems proved on ZF.ML;
  5817 
  5818 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5819   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5820   disjointness reasoning but breaking a few old proofs.
  5821 
  5822 * ZF/Update: new theory of function updates
  5823     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5824   may also be iterated as in f(a:=b,c:=d,...);
  5825 
  5826 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5827 
  5828 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5829   [previously, this check worked only if the rewrite rule was unconditional]
  5830   Now rew can involve either definitions or equalities (either == or =).
  5831 
  5832 * case_tac provided for compatibility with HOL
  5833     (like the old excluded_middle_tac, but with subgoals swapped)
  5834 
  5835 
  5836 *** Internal programming interfaces ***
  5837 
  5838 * Pure: several new basic modules made available for general use, see
  5839 also src/Pure/README;
  5840 
  5841 * improved the theory data mechanism to support encapsulation (data
  5842 kind name replaced by private Object.kind, acting as authorization
  5843 key); new type-safe user interface via functor TheoryDataFun; generic
  5844 print_data function becomes basically useless;
  5845 
  5846 * removed global_names compatibility flag -- all theory declarations
  5847 are qualified by default;
  5848 
  5849 * module Pure/Syntax now offers quote / antiquote translation
  5850 functions (useful for Hoare logic etc. with implicit dependencies);
  5851 see HOL/ex/Antiquote for an example use;
  5852 
  5853 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5854 cterm -> thm;
  5855 
  5856 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5857 subgoal;
  5858 
  5859 * Display.print_goals function moved to Locale.print_goals;
  5860 
  5861 * standard print function for goals supports current_goals_markers
  5862 variable for marking begin of proof, end of proof, start of goal; the
  5863 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5864 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5865 for example;
  5866 
  5867 
  5868 
  5869 New in Isabelle98 (January 1998)
  5870 --------------------------------
  5871 
  5872 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5873 
  5874 * changed lexical syntax of terms / types: dots made part of long
  5875 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5876 
  5877 * simpset (and claset) reference variable replaced by functions
  5878 simpset / simpset_ref;
  5879 
  5880 * no longer supports theory aliases (via merge) and non-trivial
  5881 implicit merge of thms' signatures;
  5882 
  5883 * most internal names of constants changed due to qualified names;
  5884 
  5885 * changed Pure/Sequence interface (see Pure/seq.ML);
  5886 
  5887 
  5888 *** General Changes ***
  5889 
  5890 * hierachically structured name spaces (for consts, types, axms, thms
  5891 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5892 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5893 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5894 long_names for fully qualified output names; NOTE: ML programs
  5895 (special tactics, packages etc.) referring to internal names may have
  5896 to be adapted to cope with fully qualified names; in case of severe
  5897 backward campatibility problems try setting 'global_names' at compile
  5898 time to have enrything declared within a flat name space; one may also
  5899 fine tune name declarations in theories via the 'global' and 'local'
  5900 section;
  5901 
  5902 * reimplemented the implicit simpset and claset using the new anytype
  5903 data filed in signatures; references simpset:simpset ref etc. are
  5904 replaced by functions simpset:unit->simpset and
  5905 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5906 to patch your ML files accordingly;
  5907 
  5908 * HTML output now includes theory graph data for display with Java
  5909 applet or isatool browser; data generated automatically via isatool
  5910 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5911 
  5912 * defs may now be conditional; improved rewrite_goals_tac to handle
  5913 conditional equations;
  5914 
  5915 * defs now admits additional type arguments, using TYPE('a) syntax;
  5916 
  5917 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5918 creates a new theory node; implicit merge of thms' signatures is
  5919 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5920 transfer:theory->thm->thm in (rare) cases;
  5921 
  5922 * improved handling of draft signatures / theories; draft thms (and
  5923 ctyps, cterms) are automatically promoted to real ones;
  5924 
  5925 * slightly changed interfaces for oracles: admit many per theory, named
  5926 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5927 
  5928 * print_goals: optional output of const types (set show_consts and
  5929 show_types);
  5930 
  5931 * improved output of warnings (###) and errors (***);
  5932 
  5933 * subgoal_tac displays a warning if the new subgoal has type variables;
  5934 
  5935 * removed old README and Makefiles;
  5936 
  5937 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5938 
  5939 * removed obsolete init_pps and init_database;
  5940 
  5941 * deleted the obsolete tactical STATE, which was declared by
  5942     fun STATE tacfun st = tacfun st st;
  5943 
  5944 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5945 (which abbreviates $HOME);
  5946 
  5947 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5948 use isatool fixseq to adapt your ML programs (this works for fully
  5949 qualified references to the Sequence structure only!);
  5950 
  5951 * use_thy no longer requires writable current directory; it always
  5952 reloads .ML *and* .thy file, if either one is out of date;
  5953 
  5954 
  5955 *** Classical Reasoner ***
  5956 
  5957 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5958 tactics that use classical reasoning to simplify a subgoal without
  5959 splitting it into several subgoals;
  5960 
  5961 * Safe_tac: like safe_tac but uses the default claset;
  5962 
  5963 
  5964 *** Simplifier ***
  5965 
  5966 * added simplification meta rules:
  5967     (asm_)(full_)simplify: simpset -> thm -> thm;
  5968 
  5969 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5970 logics (again);
  5971 
  5972 * added prems argument to simplification procedures;
  5973 
  5974 * HOL, FOL, ZF: added infix function `addsplits':
  5975   instead of `<simpset> setloop (split_tac <thms>)'
  5976   you can simply write `<simpset> addsplits <thms>'
  5977 
  5978 
  5979 *** Syntax ***
  5980 
  5981 * TYPE('a) syntax for type reflection terms;
  5982 
  5983 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5984 
  5985 * pretty printer: changed order of mixfix annotation preference (again!);
  5986 
  5987 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5988 
  5989 
  5990 *** HOL ***
  5991 
  5992 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  5993   with `addloop' of the simplifier to faciliate case splitting in premises.
  5994 
  5995 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  5996 
  5997 * HOL/Auth: new protocol proofs including some for the Internet
  5998   protocol TLS;
  5999 
  6000 * HOL/Map: new theory of `maps' a la VDM;
  6001 
  6002 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6003 cancelling out common nat summands from =, <, <= (in)equalities, or
  6004 differences; simplification procedures nat_cancel_factor for
  6005 cancelling common factor from =, <, <= (in)equalities over natural
  6006 sums; nat_cancel contains both kinds of procedures, it is installed by
  6007 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6008 
  6009 * HOL/simplifier: terms of the form
  6010   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6011   are rewritten to
  6012   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6013   and those of the form
  6014   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6015   are rewritten to
  6016   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6017 
  6018 * HOL/datatype
  6019   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6020 
  6021   P(t_case f1 ... fn x) =
  6022      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6023         ...
  6024        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6025      )
  6026 
  6027   and a theorem `split_t_case_asm' of the form
  6028 
  6029   P(t_case f1 ... fn x) =
  6030     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6031         ...
  6032        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6033      )
  6034   which can be added to a simpset via `addsplits'. The existing theorems
  6035   expand_list_case and expand_option_case have been renamed to
  6036   split_list_case and split_option_case.
  6037 
  6038 * HOL/Arithmetic:
  6039   - `pred n' is automatically converted to `n-1'.
  6040     Users are strongly encouraged not to use `pred' any longer,
  6041     because it will disappear altogether at some point.
  6042   - Users are strongly encouraged to write "0 < n" rather than
  6043     "n ~= 0". Theorems and proof tools have been modified towards this
  6044     `standard'.
  6045 
  6046 * HOL/Lists:
  6047   the function "set_of_list" has been renamed "set" (and its theorems too);
  6048   the function "nth" now takes its arguments in the reverse order and
  6049   has acquired the infix notation "!" as in "xs!n".
  6050 
  6051 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6052 
  6053 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6054   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6055 
  6056 * HOL/record: extensible records with schematic structural subtyping
  6057 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6058 still lacks various theorems and concrete record syntax;
  6059 
  6060 
  6061 *** HOLCF ***
  6062 
  6063 * removed "axioms" and "generated by" sections;
  6064 
  6065 * replaced "ops" section by extended "consts" section, which is capable of
  6066   handling the continuous function space "->" directly;
  6067 
  6068 * domain package:
  6069   . proves theorems immediately and stores them in the theory,
  6070   . creates hierachical name space,
  6071   . now uses normal mixfix annotations (instead of cinfix...),
  6072   . minor changes to some names and values (for consistency),
  6073   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6074   . separator between mutual domain defs: changed "," to "and",
  6075   . improved handling of sort constraints;  now they have to
  6076     appear on the left-hand side of the equations only;
  6077 
  6078 * fixed LAM <x,y,zs>.b syntax;
  6079 
  6080 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6081 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6082 
  6083 
  6084 *** FOL and ZF ***
  6085 
  6086 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6087   with `addloop' of the simplifier to faciliate case splitting in premises.
  6088 
  6089 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6090 in HOL, they strip ALL and --> from proved theorems;
  6091 
  6092 
  6093 
  6094 New in Isabelle94-8 (May 1997)
  6095 ------------------------------
  6096 
  6097 *** General Changes ***
  6098 
  6099 * new utilities to build / run / maintain Isabelle etc. (in parts
  6100 still somewhat experimental); old Makefiles etc. still functional;
  6101 
  6102 * new 'Isabelle System Manual';
  6103 
  6104 * INSTALL text, together with ./configure and ./build scripts;
  6105 
  6106 * reimplemented type inference for greater efficiency, better error
  6107 messages and clean internal interface;
  6108 
  6109 * prlim command for dealing with lots of subgoals (an easier way of
  6110 setting goals_limit);
  6111 
  6112 
  6113 *** Syntax ***
  6114 
  6115 * supports alternative (named) syntax tables (parser and pretty
  6116 printer); internal interface is provided by add_modesyntax(_i);
  6117 
  6118 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6119 be used in conjunction with the Isabelle symbol font; uses the
  6120 "symbols" syntax table;
  6121 
  6122 * added token_translation interface (may translate name tokens in
  6123 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6124 the current print_mode); IMPORTANT: user print translation functions
  6125 are responsible for marking newly introduced bounds
  6126 (Syntax.mark_boundT);
  6127 
  6128 * token translations for modes "xterm" and "xterm_color" that display
  6129 names in bold, underline etc. or colors (which requires a color
  6130 version of xterm);
  6131 
  6132 * infixes may now be declared with names independent of their syntax;
  6133 
  6134 * added typed_print_translation (like print_translation, but may
  6135 access type of constant);
  6136 
  6137 
  6138 *** Classical Reasoner ***
  6139 
  6140 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6141 some limitations.  Blast_tac...
  6142   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6143   + ignores elimination rules that don't have the correct format
  6144         (the conclusion MUST be a formula variable)
  6145   + ignores types, which can make HOL proofs fail
  6146   + rules must not require higher-order unification, e.g. apply_type in ZF
  6147     [message "Function Var's argument not a bound variable" relates to this]
  6148   + its proof strategy is more general but can actually be slower
  6149 
  6150 * substitution with equality assumptions no longer permutes other
  6151 assumptions;
  6152 
  6153 * minor changes in semantics of addafter (now called addaltern); renamed
  6154 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6155 (and access functions for it);
  6156 
  6157 * improved combination of classical reasoner and simplifier:
  6158   + functions for handling clasimpsets
  6159   + improvement of addss: now the simplifier is called _after_ the
  6160     safe steps.
  6161   + safe variant of addss called addSss: uses safe simplifications
  6162     _during_ the safe steps. It is more complete as it allows multiple
  6163     instantiations of unknowns (e.g. with slow_tac).
  6164 
  6165 *** Simplifier ***
  6166 
  6167 * added interface for simplification procedures (functions that
  6168 produce *proven* rewrite rules on the fly, depending on current
  6169 redex);
  6170 
  6171 * ordering on terms as parameter (used for ordered rewriting);
  6172 
  6173 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6174 
  6175 * the solver is now split into a safe and an unsafe part.
  6176 This should be invisible for the normal user, except that the
  6177 functions setsolver and addsolver have been renamed to setSolver and
  6178 addSolver; added safe_asm_full_simp_tac;
  6179 
  6180 
  6181 *** HOL ***
  6182 
  6183 * a generic induction tactic `induct_tac' which works for all datatypes and
  6184 also for type `nat';
  6185 
  6186 * a generic case distinction tactic `exhaust_tac' which works for all
  6187 datatypes and also for type `nat';
  6188 
  6189 * each datatype comes with a function `size';
  6190 
  6191 * patterns in case expressions allow tuple patterns as arguments to
  6192 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6193 
  6194 * primrec now also works with type nat;
  6195 
  6196 * recdef: a new declaration form, allows general recursive functions to be
  6197 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6198 
  6199 * the constant for negation has been renamed from "not" to "Not" to
  6200 harmonize with FOL, ZF, LK, etc.;
  6201 
  6202 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6203 infinite lists;
  6204 
  6205 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6206 
  6207 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6208 problems in commutative rings, using axiomatic type classes for + and *;
  6209 
  6210 * more examples in HOL/MiniML and HOL/Auth;
  6211 
  6212 * more default rewrite rules for quantifiers, union/intersection;
  6213 
  6214 * a new constant `arbitrary == @x.False';
  6215 
  6216 * HOLCF/IOA replaces old HOL/IOA;
  6217 
  6218 * HOLCF changes: derived all rules and arities
  6219   + axiomatic type classes instead of classes
  6220   + typedef instead of faking type definitions
  6221   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6222   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6223   + eliminated the types void, one, tr
  6224   + use unit lift and bool lift (with translations) instead of one and tr
  6225   + eliminated blift from Lift3.thy (use Def instead of blift)
  6226   all eliminated rules are derived as theorems --> no visible changes ;
  6227 
  6228 
  6229 *** ZF ***
  6230 
  6231 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  6232 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  6233 as ZF_cs addSIs [equalityI];
  6234 
  6235 
  6236 
  6237 New in Isabelle94-7 (November 96)
  6238 ---------------------------------
  6239 
  6240 * allowing negative levels (as offsets) in prlev and choplev;
  6241 
  6242 * super-linear speedup for large simplifications;
  6243 
  6244 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  6245 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  6246 FAIL); can suppress it using the command Delsimps (ex_simps @
  6247 all_simps); De Morgan laws are also now included, by default;
  6248 
  6249 * improved printing of ==>  :  ~:
  6250 
  6251 * new object-logic "Sequents" adds linear logic, while replacing LK
  6252 and Modal (thanks to Sara Kalvala);
  6253 
  6254 * HOL/Auth: correctness proofs for authentication protocols;
  6255 
  6256 * HOL: new auto_tac combines rewriting and classical reasoning (many
  6257 examples on HOL/Auth);
  6258