NEWS
author haftmann
Tue Jul 14 10:53:44 2009 +0200 (2009-07-14)
changeset 31997 de0d280c31a7
parent 31971 8c1b845ed105
child 32061 11f8ee55662d
child 32066 091f1e304120
permissions -rw-r--r--
NEWS and CONTRIBUTORS
     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 * Code generator attributes follow the usual underscore convention:
    22     code_unfold     replaces    code unfold
    23     code_post       replaces    code post
    24     etc.
    25   INCOMPATIBILITY.
    26 
    27 * New quickcheck implementation using new code generator.
    28 
    29 * New type class boolean_algebra.
    30 
    31 * Class semiring_div requires superclass no_zero_divisors and proof of
    32 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    33 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    34 generalized to class semiring_div, subsuming former theorems
    35 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    36 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    37 INCOMPATIBILITY.
    38 
    39 * Power operations on relations and functions are now one dedicate
    40 constant compow with infix syntax "^^".  Power operations on
    41 multiplicative monoids retains syntax "^" and is now defined generic
    42 in class power.  INCOMPATIBILITY.
    43 
    44 * ML antiquotation @{code_datatype} inserts definition of a datatype
    45 generated by the code generator; see Predicate.thy for an example.
    46 
    47 * New method "linarith" invokes existing linear arithmetic decision
    48 procedure only.
    49 
    50 * Implementation of quickcheck using generic code generator; default
    51 generators are provided for all suitable HOL types, records and
    52 datatypes.
    53 
    54 * Constants Set.Pow and Set.image now with authentic syntax;
    55 object-logic definitions Set.Pow_def and Set.image_def.
    56 INCOMPATIBILITY.
    57 
    58 * Renamed theorems:
    59 Suc_eq_add_numeral_1 -> Suc_eq_plus1
    60 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
    61 Suc_plus1 -> Suc_eq_plus1
    62 
    63 * New sledgehammer option "Full Types" in Proof General settings menu.
    64 Causes full type information to be output to the ATPs.  This slows
    65 ATPs down considerably but eliminates a source of unsound "proofs"
    66 that fail later.
    67 
    68 * Discontinued ancient tradition to suffix certain ML module names
    69 with "_package", e.g.:
    70 
    71     DatatypePackage ~> Datatype
    72     InductivePackage ~> Inductive
    73 
    74     etc.
    75 
    76 INCOMPATIBILITY.
    77 
    78 * NewNumberTheory: Jeremy Avigad's new version of part of
    79 NumberTheory.  If possible, use NewNumberTheory, not NumberTheory.
    80 
    81 * Simplified interfaces of datatype module.  INCOMPATIBILITY.
    82 
    83 * Abbreviation "arbitrary" of "undefined" has disappeared; use
    84 "undefined" directly.  INCOMPATIBILITY.
    85 
    86 * New evaluator "approximate" approximates an real valued term using
    87 the same method as the approximation method.
    88 
    89 * Method "approximate" supports now arithmetic expressions as
    90 boundaries of intervals and implements interval splitting and Taylor
    91 series expansion.
    92 
    93 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
    94 the theorems in DERIV_intros assumes composition with an additional
    95 function and matches a variable to the derivative, which has to be
    96 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
    97 the derivative of most elementary terms.
    98 
    99 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   100 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   101 
   102 
   103 *** ML ***
   104 
   105 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   106 functors have their own ML name space there is no point to mark them
   107 separately.)  Minor INCOMPATIBILITY.
   108 
   109 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   110 
   111 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   112 cominators for "args".  INCOMPATIBILITY, need to use simplified
   113 Attrib/Method.setup introduced in Isabelle2009.
   114 
   115 
   116 *** System ***
   117 
   118 * Discontinued support for Poly/ML 4.x versions.
   119 
   120 * Removed "compress" option from isabelle-process and isabelle usedir;
   121 this is always enabled.
   122 
   123 
   124 
   125 New in Isabelle2009 (April 2009)
   126 --------------------------------
   127 
   128 *** General ***
   129 
   130 * Simplified main Isabelle executables, with less surprises on
   131 case-insensitive file-systems (such as Mac OS).
   132 
   133   - The main Isabelle tool wrapper is now called "isabelle" instead of
   134     "isatool."
   135 
   136   - The former "isabelle" alias for "isabelle-process" has been
   137     removed (should rarely occur to regular users).
   138 
   139   - The former "isabelle-interface" and its alias "Isabelle" have been
   140     removed (interfaces are now regular Isabelle tools).
   141 
   142 Within scripts and make files, the Isabelle environment variables
   143 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   144 respectively.  (The latter are still available as legacy feature.)
   145 
   146 The old isabelle-interface wrapper could react in confusing ways if
   147 the interface was uninstalled or changed otherwise.  Individual
   148 interface tool configuration is now more explicit, see also the
   149 Isabelle system manual.  In particular, Proof General is now available
   150 via "isabelle emacs".
   151 
   152 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   153 purge installed copies of Isabelle executables and re-run "isabelle
   154 install -p ...", or use symlinks.
   155 
   156 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   157 old ~/isabelle, which was slightly non-standard and apt to cause
   158 surprises on case-insensitive file-systems (such as Mac OS).
   159 
   160 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   161 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   162 care is required when using older releases of Isabelle.  Note that
   163 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   164 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   165 
   166 * Proofs of fully specified statements are run in parallel on
   167 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   168 a regular 4-core machine, if the initial heap space is made reasonably
   169 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   170 
   171 * The main reference manuals ("isar-ref", "implementation", and
   172 "system") have been updated and extended.  Formally checked references
   173 as hyperlinks are now available uniformly.
   174 
   175 
   176 *** Pure ***
   177 
   178 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   179 respects.  The most important changes are listed below.  See the
   180 Tutorial on Locales ("locales" manual) for details.
   181 
   182 - In locale expressions, instantiation replaces renaming.  Parameters
   183 must be declared in a for clause.  To aid compatibility with previous
   184 parameter inheritance, in locale declarations, parameters that are not
   185 'touched' (instantiation position "_" or omitted) are implicitly added
   186 with their syntax at the beginning of the for clause.
   187 
   188 - Syntax from abbreviations and definitions in locales is available in
   189 locale expressions and context elements.  The latter is particularly
   190 useful in locale declarations.
   191 
   192 - More flexible mechanisms to qualify names generated by locale
   193 expressions.  Qualifiers (prefixes) may be specified in locale
   194 expressions, and can be marked as mandatory (syntax: "name!:") or
   195 optional (syntax "name?:").  The default depends for plain "name:"
   196 depends on the situation where a locale expression is used: in
   197 commands 'locale' and 'sublocale' prefixes are optional, in
   198 'interpretation' and 'interpret' prefixes are mandatory.  The old
   199 implicit qualifiers derived from the parameter names of a locale are
   200 no longer generated.
   201 
   202 - Command "sublocale l < e" replaces "interpretation l < e".  The
   203 instantiation clause in "interpretation" and "interpret" (square
   204 brackets) is no longer available.  Use locale expressions.
   205 
   206 - When converting proof scripts, mandatory qualifiers in
   207 'interpretation' and 'interpret' should be retained by default, even
   208 if this is an INCOMPATIBILITY compared to former behavior.  In the
   209 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   210 in locale expressions range over a single locale instance only.
   211 
   212 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   213 In existing theorem specifications replace the includes element by the
   214 respective context elements of the included locale, omitting those
   215 that are already present in the theorem specification.  Multiple
   216 assume elements of a locale should be replaced by a single one
   217 involving the locale predicate.  In the proof body, declarations (most
   218 notably theorems) may be regained by interpreting the respective
   219 locales in the proof context as required (command "interpret").
   220 
   221 If using "includes" in replacement of a target solely because the
   222 parameter types in the theorem are not as general as in the target,
   223 consider declaring a new locale with additional type constraints on
   224 the parameters (context element "constrains").
   225 
   226 - Discontinued "locale (open)".  INCOMPATIBILITY.
   227 
   228 - Locale interpretation commands no longer attempt to simplify goal.
   229 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   230 methods intro_locales and unfold_locales to clarify.
   231 
   232 - Locale interpretation commands no longer accept interpretation
   233 attributes.  INCOMPATIBILITY.
   234 
   235 * Class declaration: so-called "base sort" must not be given in import
   236 list any longer, but is inferred from the specification.  Particularly
   237 in HOL, write
   238 
   239     class foo = ...
   240 
   241 instead of
   242 
   243     class foo = type + ...
   244 
   245 * Class target: global versions of theorems stemming do not carry a
   246 parameter prefix any longer.  INCOMPATIBILITY.
   247 
   248 * Class 'instance' command no longer accepts attached definitions.
   249 INCOMPATIBILITY, use proper 'instantiation' target instead.
   250 
   251 * Recovered hiding of consts, which was accidentally broken in
   252 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   253 makes c inaccessible; consider using ``hide (open) const c'' instead.
   254 
   255 * Slightly more coherent Pure syntax, with updated documentation in
   256 isar-ref manual.  Removed locales meta_term_syntax and
   257 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   258 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   259 directly in regular applications.
   260 
   261 * There is a new syntactic category "float_const" for signed decimal
   262 fractions (e.g. 123.45 or -123.45).
   263 
   264 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   265 interface with 'setup' command instead.
   266 
   267 * Command 'local_setup' is similar to 'setup', but operates on a local
   268 theory context.
   269 
   270 * The 'axiomatization' command now only works within a global theory
   271 context.  INCOMPATIBILITY.
   272 
   273 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   274 hypotheses.  Sorts required in the course of reasoning need to be
   275 covered by the constraints in the initial statement, completed by the
   276 type instance information of the background theory.  Non-trivial sort
   277 hypotheses, which rarely occur in practice, may be specified via
   278 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   279 
   280   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   281 
   282 The result contains an implicit sort hypotheses as before --
   283 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   284 normalization.
   285 
   286 * Generalized Isar history, with support for linear undo, direct state
   287 addressing etc.
   288 
   289 * Changed defaults for unify configuration options:
   290 
   291   unify_trace_bound = 50 (formerly 25)
   292   unify_search_bound = 60 (formerly 30)
   293 
   294 * Different bookkeeping for code equations (INCOMPATIBILITY):
   295 
   296   a) On theory merge, the last set of code equations for a particular
   297      constant is taken (in accordance with the policy applied by other
   298      parts of the code generator framework).
   299 
   300   b) Code equations stemming from explicit declarations (e.g. code
   301      attribute) gain priority over default code equations stemming
   302      from definition, primrec, fun etc.
   303 
   304 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   305 
   306 * Unified theorem tables for both code generators.  Thus [code
   307 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   308 
   309 * Command 'find_consts' searches for constants based on type and name
   310 patterns, e.g.
   311 
   312     find_consts "_ => bool"
   313 
   314 By default, matching is against subtypes, but it may be restricted to
   315 the whole type.  Searching by name is possible.  Multiple queries are
   316 conjunctive and queries may be negated by prefixing them with a
   317 hyphen:
   318 
   319     find_consts strict: "_ => bool" name: "Int" -"int => int"
   320 
   321 * New 'find_theorems' criterion "solves" matches theorems that
   322 directly solve the current goal (modulo higher-order unification).
   323 
   324 * Auto solve feature for main theorem statements: whenever a new goal
   325 is stated, "find_theorems solves" is called; any theorems that could
   326 solve the lemma directly are listed as part of the goal state.
   327 Cf. associated options in Proof General Isabelle settings menu,
   328 enabled by default, with reasonable timeout for pathological cases of
   329 higher-order unification.
   330 
   331 
   332 *** Document preparation ***
   333 
   334 * Antiquotation @{lemma} now imitates a regular terminal proof,
   335 demanding keyword 'by' and supporting the full method expression
   336 syntax just like the Isar command 'by'.
   337 
   338 
   339 *** HOL ***
   340 
   341 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   342 points Main and Complex_Main remain as before.
   343 
   344 * Logic image HOL-Plain provides a minimal HOL with the most important
   345 tools available (inductive, datatype, primrec, ...).  This facilitates
   346 experimentation and tool development.  Note that user applications
   347 (and library theories) should never refer to anything below theory
   348 Main, as before.
   349 
   350 * Logic image HOL-Main stops at theory Main, and thus facilitates
   351 experimentation due to shorter build times.
   352 
   353 * Logic image HOL-NSA contains theories of nonstandard analysis which
   354 were previously part of former HOL-Complex.  Entry point Hyperreal
   355 remains valid, but theories formerly using Complex_Main should now use
   356 new entry point Hypercomplex.
   357 
   358 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   359 Posix processes.  Avoids potentially expensive forking of the ML
   360 process.  New thread-based implementation also works on non-Unix
   361 platforms (Cygwin).  Provers are no longer hardwired, but defined
   362 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   363 commands are covered in the isar-ref manual.
   364 
   365 * Wrapper scripts for remote SystemOnTPTP service allows to use
   366 sledgehammer without local ATP installation (Vampire etc.). Other
   367 provers may be included via suitable ML wrappers, see also
   368 src/HOL/ATP_Linkup.thy.
   369 
   370 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   371 menu.
   372 
   373 * The metis method no longer fails because the theorem is too trivial
   374 (contains the empty clause).
   375 
   376 * The metis method now fails in the usual manner, rather than raising
   377 an exception, if it determines that it cannot prove the theorem.
   378 
   379 * Method "coherent" implements a prover for coherent logic (see also
   380 src/Tools/coherent.ML).
   381 
   382 * Constants "undefined" and "default" replace "arbitrary".  Usually
   383 "undefined" is the right choice to replace "arbitrary", though
   384 logically there is no difference.  INCOMPATIBILITY.
   385 
   386 * Command "value" now integrates different evaluation mechanisms.  The
   387 result of the first successful evaluation mechanism is printed.  In
   388 square brackets a particular named evaluation mechanisms may be
   389 specified (currently, [SML], [code] or [nbe]).  See further
   390 src/HOL/ex/Eval_Examples.thy.
   391 
   392 * Normalization by evaluation now allows non-leftlinear equations.
   393 Declare with attribute [code nbe].
   394 
   395 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   396 as the structured Isar versions "cases" and "induct", cf. the
   397 corresponding "cases" and "induct" attributes.  Mutual induction rules
   398 are now presented as a list of individual projections
   399 (e.g. foo_bar.inducts for types foo and bar); the old format with
   400 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   401 rare situations a different rule is selected --- notably nested tuple
   402 elimination instead of former prod.exhaust: use explicit (case_tac t
   403 rule: prod.exhaust) here.
   404 
   405 * Attributes "cases", "induct", "coinduct" support "del" option.
   406 
   407 * Removed fact "case_split_thm", which duplicates "case_split".
   408 
   409 * The option datatype has been moved to a new theory Option.  Renamed
   410 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   411 
   412 * New predicate "strict_mono" classifies strict functions on partial
   413 orders.  With strict functions on linear orders, reasoning about
   414 (in)equalities is facilitated by theorems "strict_mono_eq",
   415 "strict_mono_less_eq" and "strict_mono_less".
   416 
   417 * Some set operations are now proper qualified constants with
   418 authentic syntax.  INCOMPATIBILITY:
   419 
   420     op Int ~>   Set.Int
   421     op Un ~>    Set.Un
   422     INTER ~>    Set.INTER
   423     UNION ~>    Set.UNION
   424     Inter ~>    Set.Inter
   425     Union ~>    Set.Union
   426     {} ~>       Set.empty
   427     UNIV ~>     Set.UNIV
   428 
   429 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   430 theory Set.
   431 
   432 * Auxiliary class "itself" has disappeared -- classes without any
   433 parameter are treated as expected by the 'class' command.
   434 
   435 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   436 
   437 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   438 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   439 
   440 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   441 method "approximation".  It proves formulas on real values by using
   442 interval arithmetic.  In the formulas are also the transcendental
   443 functions sin, cos, tan, atan, ln, exp and the constant pi are
   444 allowed. For examples see
   445 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   446 
   447 * Theory "Reflection" now resides in HOL/Library.
   448 
   449 * Entry point to Word library now simply named "Word".
   450 INCOMPATIBILITY.
   451 
   452 * Made source layout more coherent with logical distribution
   453 structure:
   454 
   455     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   456     src/HOL/Library/Code_Message.thy ~> src/HOL/
   457     src/HOL/Library/GCD.thy ~> src/HOL/
   458     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   459     src/HOL/Library/Parity.thy ~> src/HOL/
   460     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   461     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   462     src/HOL/Real/Lubs.thy ~> src/HOL/
   463     src/HOL/Real/PReal.thy ~> src/HOL/
   464     src/HOL/Real/Rational.thy ~> src/HOL/
   465     src/HOL/Real/RComplete.thy ~> src/HOL/
   466     src/HOL/Real/RealDef.thy ~> src/HOL/
   467     src/HOL/Real/RealPow.thy ~> src/HOL/
   468     src/HOL/Real/Real.thy ~> src/HOL/
   469     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   470     src/HOL/Complex/Complex.thy ~> src/HOL/
   471     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   472     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   473     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   474     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   475     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   476     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   477     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   478     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   479     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   480     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   481     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   482     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   483     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   484     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   485     src/HOL/Real/Float ~> src/HOL/Library/
   486     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   487     src/HOL/Real/RealVector.thy ~> src/HOL/
   488 
   489     src/HOL/arith_data.ML ~> src/HOL/Tools
   490     src/HOL/hologic.ML ~> src/HOL/Tools
   491     src/HOL/simpdata.ML ~> src/HOL/Tools
   492     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   493     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   494     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   495     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   496     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   497     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   498     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   499 
   500     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   501     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   502     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   503     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   504     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   505     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   506 
   507 * If methods "eval" and "evaluation" encounter a structured proof
   508 state with !!/==>, only the conclusion is evaluated to True (if
   509 possible), avoiding strange error messages.
   510 
   511 * Method "sizechange" automates termination proofs using (a
   512 modification of) the size-change principle.  Requires SAT solver.  See
   513 src/HOL/ex/Termination.thy for examples.
   514 
   515 * Simplifier: simproc for let expressions now unfolds if bound
   516 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   517 
   518 * Method "arith": Linear arithmetic now ignores all inequalities when
   519 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   520 
   521 * New attribute "arith" for facts that should always be used
   522 automatically by arithmetic. It is intended to be used locally in
   523 proofs, e.g.
   524 
   525   assumes [arith]: "x > 0"
   526 
   527 Global usage is discouraged because of possible performance impact.
   528 
   529 * New classes "top" and "bot" with corresponding operations "top" and
   530 "bot" in theory Orderings; instantiation of class "complete_lattice"
   531 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   532 
   533 * Changed definition lemma "less_fun_def" in order to provide an
   534 instance for preorders on functions; use lemma "less_le" instead.
   535 INCOMPATIBILITY.
   536 
   537 * Theory Orderings: class "wellorder" moved here, with explicit
   538 induction rule "less_induct" as assumption.  For instantiation of
   539 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   540 INCOMPATIBILITY.
   541 
   542 * Theory Orderings: added class "preorder" as superclass of "order".
   543 INCOMPATIBILITY: Instantiation proofs for order, linorder
   544 etc. slightly changed.  Some theorems named order_class.* now named
   545 preorder_class.*.
   546 
   547 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   548 "diag" to "Id_on".
   549 
   550 * Theory Finite_Set: added a new fold combinator of type
   551 
   552   ('a => 'b => 'b) => 'b => 'a set => 'b
   553 
   554 Occasionally this is more convenient than the old fold combinator
   555 which is now defined in terms of the new one and renamed to
   556 fold_image.
   557 
   558 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   559 and "ring_simps" have been replaced by "algebra_simps" (which can be
   560 extended with further lemmas!).  At the moment both still exist but
   561 the former will disappear at some point.
   562 
   563 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   564 class recpower.  Type-specific simp rules for various recpower types
   565 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   566 
   567 rat_power_0    -> power_0
   568 rat_power_Suc  -> power_Suc
   569 realpow_0      -> power_0
   570 realpow_Suc    -> power_Suc
   571 complexpow_0   -> power_0
   572 complexpow_Suc -> power_Suc
   573 power_poly_0   -> power_0
   574 power_poly_Suc -> power_Suc
   575 
   576 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   577 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   578 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   579 of lemmas from Divides has been generalized from nat to class
   580 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   581 renames resulting from duplicate elimination:
   582 
   583     dvd_def_mod ~>          dvd_eq_mod_eq_0
   584     zero_dvd_iff ~>         dvd_0_left_iff
   585     dvd_0 ~>                dvd_0_right
   586     DIVISION_BY_ZERO_DIV ~> div_by_0
   587     DIVISION_BY_ZERO_MOD ~> mod_by_0
   588     mult_div ~>             div_mult_self2_is_id
   589     mult_mod ~>             mod_mult_self2_is_0
   590 
   591 * Theory IntDiv: removed many lemmas that are instances of class-based
   592 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   593 rename old lemmas as follows:
   594 
   595 dvd_diff               -> nat_dvd_diff
   596 dvd_zminus_iff         -> dvd_minus_iff
   597 mod_add1_eq            -> mod_add_eq
   598 mod_mult1_eq           -> mod_mult_right_eq
   599 mod_mult1_eq'          -> mod_mult_left_eq
   600 mod_mult_distrib_mod   -> mod_mult_eq
   601 nat_mod_add_left_eq    -> mod_add_left_eq
   602 nat_mod_add_right_eq   -> mod_add_right_eq
   603 nat_mod_div_trivial    -> mod_div_trivial
   604 nat_mod_mod_trivial    -> mod_mod_trivial
   605 zdiv_zadd_self1        -> div_add_self1
   606 zdiv_zadd_self2        -> div_add_self2
   607 zdiv_zmult_self1       -> div_mult_self2_is_id
   608 zdiv_zmult_self2       -> div_mult_self1_is_id
   609 zdvd_triv_left         -> dvd_triv_left
   610 zdvd_triv_right        -> dvd_triv_right
   611 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   612 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   613 zmod_zadd_left_eq      -> mod_add_left_eq
   614 zmod_zadd_right_eq     -> mod_add_right_eq
   615 zmod_zadd_self1        -> mod_add_self1
   616 zmod_zadd_self2        -> mod_add_self2
   617 zmod_zadd1_eq          -> mod_add_eq
   618 zmod_zdiff1_eq         -> mod_diff_eq
   619 zmod_zdvd_zmod         -> mod_mod_cancel
   620 zmod_zmod_cancel       -> mod_mod_cancel
   621 zmod_zmult_self1       -> mod_mult_self2_is_0
   622 zmod_zmult_self2       -> mod_mult_self1_is_0
   623 zmod_1                 -> mod_by_1
   624 zdiv_1                 -> div_by_1
   625 zdvd_abs1              -> abs_dvd_iff
   626 zdvd_abs2              -> dvd_abs_iff
   627 zdvd_refl              -> dvd_refl
   628 zdvd_trans             -> dvd_trans
   629 zdvd_zadd              -> dvd_add
   630 zdvd_zdiff             -> dvd_diff
   631 zdvd_zminus_iff        -> dvd_minus_iff
   632 zdvd_zminus2_iff       -> minus_dvd_iff
   633 zdvd_zmultD            -> dvd_mult_right
   634 zdvd_zmultD2           -> dvd_mult_left
   635 zdvd_zmult_mono        -> mult_dvd_mono
   636 zdvd_0_right           -> dvd_0_right
   637 zdvd_0_left            -> dvd_0_left_iff
   638 zdvd_1_left            -> one_dvd
   639 zminus_dvd_iff         -> minus_dvd_iff
   640 
   641 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   642 
   643 * The real numbers offer decimal input syntax: 12.34 is translated
   644 into 1234/10^2. This translation is not reversed upon output.
   645 
   646 * Theory Library/Polynomial defines an abstract type 'a poly of
   647 univariate polynomials with coefficients of type 'a.  In addition to
   648 the standard ring operations, it also supports div and mod.  Code
   649 generation is also supported, using list-style constructors.
   650 
   651 * Theory Library/Inner_Product defines a class of real_inner for real
   652 inner product spaces, with an overloaded operation inner :: 'a => 'a
   653 => real.  Class real_inner is a subclass of real_normed_vector from
   654 theory RealVector.
   655 
   656 * Theory Library/Product_Vector provides instances for the product
   657 type 'a * 'b of several classes from RealVector and Inner_Product.
   658 Definitions of addition, subtraction, scalar multiplication, norms,
   659 and inner products are included.
   660 
   661 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   662 addition to the field operations, numerals and case syntax are also
   663 supported.
   664 
   665 * Theory Library/Diagonalize provides constructive version of Cantor's
   666 first diagonalization argument.
   667 
   668 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   669 zlcm (for int); carried together from various gcd/lcm developements in
   670 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   671 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   672 may recover tupled syntax as follows:
   673 
   674     hide (open) const gcd
   675     abbreviation gcd where
   676       "gcd == (%(a, b). GCD.gcd a b)"
   677     notation (output)
   678       GCD.gcd ("gcd '(_, _')")
   679 
   680 The same works for lcm, zgcd, zlcm.
   681 
   682 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   683 instantiations for algebraic structures.  Removed some duplicate
   684 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   685 
   686 * ML antiquotation @{code} takes a constant as argument and generates
   687 corresponding code in background and inserts name of the corresponding
   688 resulting ML value/function/datatype constructor binding in place.
   689 All occurrences of @{code} with a single ML block are generated
   690 simultaneously.  Provides a generic and safe interface for
   691 instrumentalizing code generation.  See
   692 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   693 In future you ought to refrain from ad-hoc compiling generated SML
   694 code on the ML toplevel.  Note that (for technical reasons) @{code}
   695 cannot refer to constants for which user-defined serializations are
   696 set.  Refer to the corresponding ML counterpart directly in that
   697 cases.
   698 
   699 * Command 'rep_datatype': instead of theorem names the command now
   700 takes a list of terms denoting the constructors of the type to be
   701 represented as datatype.  The characteristic theorems have to be
   702 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   703 have disappeared in favour of existing ones:
   704 
   705     unit_induct                 ~> unit.induct
   706     prod_induct                 ~> prod.induct
   707     sum_induct                  ~> sum.induct
   708     Suc_Suc_eq                  ~> nat.inject
   709     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   710 
   711 
   712 *** HOL-Algebra ***
   713 
   714 * New locales for orders and lattices where the equivalence relation
   715 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   716 locales use a record structure with field eq for the equivalence.
   717 
   718 * New theory of factorial domains.
   719 
   720 * Units_l_inv and Units_r_inv are now simp rules by default.
   721 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   722 and/or r_inv will now also require deletion of these lemmas.
   723 
   724 * Renamed the following theorems, INCOMPATIBILITY:
   725 
   726 UpperD ~> Upper_memD
   727 LowerD ~> Lower_memD
   728 least_carrier ~> least_closed
   729 greatest_carrier ~> greatest_closed
   730 greatest_Lower_above ~> greatest_Lower_below
   731 one_zero ~> carrier_one_zero
   732 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   733 
   734 
   735 *** HOL-Nominal ***
   736 
   737 * Nominal datatypes can now contain type-variables.
   738 
   739 * Commands 'nominal_inductive' and 'equivariance' work with local
   740 theory targets.
   741 
   742 * Nominal primrec can now works with local theory targets and its
   743 specification syntax now conforms to the general format as seen in
   744 'inductive' etc.
   745 
   746 * Method "perm_simp" honours the standard simplifier attributes
   747 (no_asm), (no_asm_use) etc.
   748 
   749 * The new predicate #* is defined like freshness, except that on the
   750 left hand side can be a set or list of atoms.
   751 
   752 * Experimental command 'nominal_inductive2' derives strong induction
   753 principles for inductive definitions.  In contrast to
   754 'nominal_inductive', which can only deal with a fixed number of
   755 binders, it can deal with arbitrary expressions standing for sets of
   756 atoms to be avoided.  The only inductive definition we have at the
   757 moment that needs this generalisation is the typing rule for Lets in
   758 the algorithm W:
   759 
   760  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   761  -----------------------------------------------------------------
   762          Gamma |- Let x be t1 in t2 : T2
   763 
   764 In this rule one wants to avoid all the binders that are introduced by
   765 "close Gamma T1".  We are looking for other examples where this
   766 feature might be useful.  Please let us know.
   767 
   768 
   769 *** HOLCF ***
   770 
   771 * Reimplemented the simplification procedure for proving continuity
   772 subgoals.  The new simproc is extensible; users can declare additional
   773 continuity introduction rules with the attribute [cont2cont].
   774 
   775 * The continuity simproc now uses a different introduction rule for
   776 solving continuity subgoals on terms with lambda abstractions.  In
   777 some rare cases the new simproc may fail to solve subgoals that the
   778 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   779 Potential INCOMPATIBILITY.
   780 
   781 * Command 'fixrec': specification syntax now conforms to the general
   782 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   783 examples.  INCOMPATIBILITY.
   784 
   785 
   786 *** ZF ***
   787 
   788 * Proof of Zorn's Lemma for partial orders.
   789 
   790 
   791 *** ML ***
   792 
   793 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   794 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   795 depends on multithreading, so timouts will not work before Poly/ML
   796 5.2.1!
   797 
   798 * High-level support for concurrent ML programming, see
   799 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   800 particularly convenient to organize independent functional
   801 computations.  The concept of "synchronized variables" provides a
   802 higher-order interface for components with shared state, avoiding the
   803 delicate details of mutexes and condition variables.  (Requires
   804 Poly/ML 5.2.1 or later.)
   805 
   806 * ML bindings produced via Isar commands are stored within the Isar
   807 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   808 become thread-safe and work with undo as expected (concerning
   809 top-level bindings, not side-effects on global references).
   810 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   811 compiler at runtime; really global bindings need to be given outside a
   812 theory.  (Requires Poly/ML 5.2 or later.)
   813 
   814 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   815 context.  Top-level ML bindings are stored within the proof context in
   816 a purely sequential fashion, disregarding the nested proof structure.
   817 ML bindings introduced by 'ML_prf' are discarded at the end of the
   818 proof.  (Requires Poly/ML 5.2 or later.)
   819 
   820 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   821 and Method.setup, as well as Isar commands 'attribute_setup' and
   822 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   823 existing code accordingly, or use plain 'setup' together with old
   824 Method.add_method.
   825 
   826 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   827 to 'a -> thm, while results are always tagged with an authentic oracle
   828 name.  The Isar command 'oracle' is now polymorphic, no argument type
   829 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   830 accordingly.  Note that extra performance may be gained by producing
   831 the cterm carefully, avoiding slow Thm.cterm_of.
   832 
   833 * Simplified interface for defining document antiquotations via
   834 ThyOutput.antiquotation, ThyOutput.output, and optionally
   835 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   836 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   837 examples.
   838 
   839 * More systematic treatment of long names, abstract name bindings, and
   840 name space operations.  Basic operations on qualified names have been
   841 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   842 Long_Name.append.  Old type bstring has been mostly replaced by
   843 abstract type binding (see structure Binding), which supports precise
   844 qualification by packages and local theory targets, as well as proper
   845 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   846 bstring values into Binding.name, or better pass through abstract
   847 bindings everywhere.  See further src/Pure/General/long_name.ML,
   848 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   849 
   850 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   851 LocalTheory.note etc.) now refer to the *full* internal name, not the
   852 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   853 
   854 * Disposed old type and term read functions (Sign.read_def_typ,
   855 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   856 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   857 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   858 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   859 resort for legacy applications.
   860 
   861 * Disposed old declarations, tactics, tactic combinators that refer to
   862 the simpset or claset of an implicit theory (such as Addsimps,
   863 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   864 embedded ML text, or local_simpset_of with a proper context passed as
   865 explicit runtime argument.
   866 
   867 * Rules and tactics that read instantiations (read_instantiate,
   868 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   869 context, which is required for parsing and type-checking.  Moreover,
   870 the variables are specified as plain indexnames, not string encodings
   871 thereof.  INCOMPATIBILITY.
   872 
   873 * Generic Toplevel.add_hook interface allows to analyze the result of
   874 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   875 for theorem dependency output of transactions resulting in a new
   876 theory state.
   877 
   878 * ML antiquotations: block-structured compilation context indicated by
   879 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   880 
   881   @{binding name}                         - basic name binding
   882   @{let ?pat = term}                      - term abbreviation (HO matching)
   883   @{note name = fact}                     - fact abbreviation
   884   @{thm fact}                             - singleton fact (with attributes)
   885   @{thms fact}                            - general fact (with attributes)
   886   @{lemma prop by method}                 - singleton goal
   887   @{lemma prop by meth1 meth2}            - singleton goal
   888   @{lemma prop1 ... propN by method}      - general goal
   889   @{lemma prop1 ... propN by meth1 meth2} - general goal
   890   @{lemma (open) ...}                     - open derivation
   891 
   892 
   893 *** System ***
   894 
   895 * The Isabelle "emacs" tool provides a specific interface to invoke
   896 Proof General / Emacs, with more explicit failure if that is not
   897 installed (the old isabelle-interface script silently falls back on
   898 isabelle-process).  The PROOFGENERAL_HOME setting determines the
   899 installation location of the Proof General distribution.
   900 
   901 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
   902 the Isabelle process into a JVM/Scala application.  See
   903 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
   904 process wrapper has been discontinued.)
   905 
   906 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
   907 
   908 * Various status messages (with exact source position information) are
   909 emitted, if proper markup print mode is enabled.  This allows
   910 user-interface components to provide detailed feedback on internal
   911 prover operations.
   912 
   913 
   914 
   915 New in Isabelle2008 (June 2008)
   916 -------------------------------
   917 
   918 *** General ***
   919 
   920 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
   921 and updated, with formally checked references as hyperlinks.
   922 
   923 * Theory loader: use_thy (and similar operations) no longer set the
   924 implicit ML context, which was occasionally hard to predict and in
   925 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
   926 provides a proper context already.
   927 
   928 * Theory loader: old-style ML proof scripts being *attached* to a thy
   929 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
   930 'use' within a theory file will do the job.
   931 
   932 * Name space merge now observes canonical order, i.e. the second space
   933 is inserted into the first one, while existing entries in the first
   934 space take precedence.  INCOMPATIBILITY in rare situations, may try to
   935 swap theory imports.
   936 
   937 * Syntax: symbol \<chi> is now considered a letter.  Potential
   938 INCOMPATIBILITY in identifier syntax etc.
   939 
   940 * Outer syntax: string tokens no longer admit escaped white space,
   941 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
   942 white space without escapes.
   943 
   944 * Outer syntax: string tokens may contain arbitrary character codes
   945 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
   946 "foo_bar".
   947 
   948 
   949 *** Pure ***
   950 
   951 * Context-dependent token translations.  Default setup reverts locally
   952 fixed variables, and adds hilite markup for undeclared frees.
   953 
   954 * Unused theorems can be found using the new command 'unused_thms'.
   955 There are three ways of invoking it:
   956 
   957 (1) unused_thms
   958      Only finds unused theorems in the current theory.
   959 
   960 (2) unused_thms thy_1 ... thy_n -
   961      Finds unused theorems in the current theory and all of its ancestors,
   962      excluding the theories thy_1 ... thy_n and all of their ancestors.
   963 
   964 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
   965      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
   966      their ancestors, excluding the theories thy_1 ... thy_n and all of
   967      their ancestors.
   968 
   969 In order to increase the readability of the list produced by
   970 unused_thms, theorems that have been created by a particular instance
   971 of a theory command such as 'inductive' or 'function' are considered
   972 to belong to the same "group", meaning that if at least one theorem in
   973 this group is used, the other theorems in the same group are no longer
   974 reported as unused.  Moreover, if all theorems in the group are
   975 unused, only one theorem in the group is displayed.
   976 
   977 Note that proof objects have to be switched on in order for
   978 unused_thms to work properly (i.e. !proofs must be >= 1, which is
   979 usually the case when using Proof General with the default settings).
   980 
   981 * Authentic naming of facts disallows ad-hoc overwriting of previous
   982 theorems within the same name space.  INCOMPATIBILITY, need to remove
   983 duplicate fact bindings, or even accidental fact duplications.  Note
   984 that tools may maintain dynamically scoped facts systematically, using
   985 PureThy.add_thms_dynamic.
   986 
   987 * Command 'hide' now allows to hide from "fact" name space as well.
   988 
   989 * Eliminated destructive theorem database, simpset, claset, and
   990 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
   991 update of theories within ML code.
   992 
   993 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
   994 INCOMPATIBILITY, object-logics depending on former Pure require
   995 additional setup PureThy.old_appl_syntax_setup; object-logics
   996 depending on former CPure need to refer to Pure.
   997 
   998 * Commands 'use' and 'ML' are now purely functional, operating on
   999 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1000 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1001 INCOMPATIBILITY.
  1002 
  1003 * Command 'setup': discontinued implicit version with ML reference.
  1004 
  1005 * Instantiation target allows for simultaneous specification of class
  1006 instance operations together with an instantiation proof.
  1007 Type-checking phase allows to refer to class operations uniformly.
  1008 See src/HOL/Complex/Complex.thy for an Isar example and
  1009 src/HOL/Library/Eval.thy for an ML example.
  1010 
  1011 * Indexing of literal facts: be more serious about including only
  1012 facts from the visible specification/proof context, but not the
  1013 background context (locale etc.).  Affects `prop` notation and method
  1014 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1015 situations.
  1016 
  1017 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1018 "(open)" option, which used to expose internal bound variables to the
  1019 proof text.
  1020 
  1021 * Isar statements: removed obsolete case "rule_context".
  1022 INCOMPATIBILITY, better use explicit fixes/assumes.
  1023 
  1024 * Locale proofs: default proof step now includes 'unfold_locales';
  1025 hence 'proof' without argument may be used to unfold locale
  1026 predicates.
  1027 
  1028 
  1029 *** Document preparation ***
  1030 
  1031 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1032 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1033 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1034 spot); renamed link color from "darkblue" to "linkcolor" (default
  1035 value unchanged, can be redefined via \definecolor); no longer sets
  1036 "a4paper" option (unnecessary or even intrusive).
  1037 
  1038 * Antiquotation @{lemma A method} proves proposition A by the given
  1039 method (either a method name or a method name plus (optional) method
  1040 arguments in parentheses) and prints A just like @{prop A}.
  1041 
  1042 
  1043 *** HOL ***
  1044 
  1045 * New primrec package.  Specification syntax conforms in style to
  1046 definition/function/....  No separate induction rule is provided.  The
  1047 "primrec" command distinguishes old-style and new-style specifications
  1048 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1049 When adjusting theories, beware: constants stemming from new-style
  1050 primrec specifications have authentic syntax.
  1051 
  1052 * Metis prover is now an order of magnitude faster, and also works
  1053 with multithreading.
  1054 
  1055 * Metis: the maximum number of clauses that can be produced from a
  1056 theorem is now given by the attribute max_clauses.  Theorems that
  1057 exceed this number are ignored, with a warning printed.
  1058 
  1059 * Sledgehammer no longer produces structured proofs by default. To
  1060 enable, declare [[sledgehammer_full = true]].  Attributes
  1061 reconstruction_modulus, reconstruction_sorts renamed
  1062 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1063 
  1064 * Method "induct_scheme" derives user-specified induction rules
  1065 from well-founded induction and completeness of patterns. This factors
  1066 out some operations that are done internally by the function package
  1067 and makes them available separately.  See
  1068 src/HOL/ex/Induction_Scheme.thy for examples.
  1069 
  1070 * More flexible generation of measure functions for termination
  1071 proofs: Measure functions can be declared by proving a rule of the
  1072 form "is_measure f" and giving it the [measure_function] attribute.
  1073 The "is_measure" predicate is logically meaningless (always true), and
  1074 just guides the heuristic.  To find suitable measure functions, the
  1075 termination prover sets up the goal "is_measure ?f" of the appropriate
  1076 type and generates all solutions by prolog-style backwards proof using
  1077 the declared rules.
  1078 
  1079 This setup also deals with rules like 
  1080 
  1081   "is_measure f ==> is_measure (list_size f)"
  1082 
  1083 which accommodates nested datatypes that recurse through lists.
  1084 Similar rules are predeclared for products and option types.
  1085 
  1086 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1087 
  1088   INCOMPATIBILITIES:
  1089 
  1090   - Definitions of overloaded constants on sets have to be replaced by
  1091     definitions on => and bool.
  1092 
  1093   - Some definitions of overloaded operators on sets can now be proved
  1094     using the definitions of the operators on => and bool.  Therefore,
  1095     the following theorems have been renamed:
  1096 
  1097       subset_def   -> subset_eq
  1098       psubset_def  -> psubset_eq
  1099       set_diff_def -> set_diff_eq
  1100       Compl_def    -> Compl_eq
  1101       Sup_set_def  -> Sup_set_eq
  1102       Inf_set_def  -> Inf_set_eq
  1103       sup_set_def  -> sup_set_eq
  1104       inf_set_def  -> inf_set_eq
  1105 
  1106   - Due to the incompleteness of the HO unification algorithm, some
  1107     rules such as subst may require manual instantiation, if some of
  1108     the unknowns in the rule is a set.
  1109 
  1110   - Higher order unification and forward proofs:
  1111     The proof pattern
  1112 
  1113       have "P (S::'a set)" <...>
  1114       then have "EX S. P S" ..
  1115 
  1116     no longer works (due to the incompleteness of the HO unification
  1117     algorithm) and must be replaced by the pattern
  1118 
  1119       have "EX S. P S"
  1120       proof
  1121         show "P S" <...>
  1122       qed
  1123 
  1124   - Calculational reasoning with subst (or similar rules):
  1125     The proof pattern
  1126 
  1127       have "P (S::'a set)" <...>
  1128       also have "S = T" <...>
  1129       finally have "P T" .
  1130 
  1131     no longer works (for similar reasons as the previous example) and
  1132     must be replaced by something like
  1133 
  1134       have "P (S::'a set)" <...>
  1135       moreover have "S = T" <...>
  1136       ultimately have "P T" by simp
  1137 
  1138   - Tactics or packages written in ML code:
  1139     Code performing pattern matching on types via
  1140 
  1141       Type ("set", [T]) => ...
  1142 
  1143     must be rewritten. Moreover, functions like strip_type or
  1144     binder_types no longer return the right value when applied to a
  1145     type of the form
  1146 
  1147       T1 => ... => Tn => U => bool
  1148 
  1149     rather than
  1150 
  1151       T1 => ... => Tn => U set
  1152 
  1153 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1154 Wellfounded_Relations to theory Wellfounded.
  1155 
  1156 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1157 
  1158 * Class finite no longer treats UNIV as class parameter.  Use class
  1159 enum from theory Library/Enum instead to achieve a similar effect.
  1160 INCOMPATIBILITY.
  1161 
  1162 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1163 and "Cons".  INCOMPATIBILITY.
  1164 
  1165 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1166 Potential INCOMPATIBILITY.
  1167 
  1168 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1169 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1170 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1171 
  1172 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1173 the same name in theory Orderings:
  1174 
  1175   less_trans
  1176   less_linear
  1177   le_imp_less_or_eq
  1178   le_less_trans
  1179   less_le_trans
  1180   less_not_sym
  1181   less_asym
  1182 
  1183 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1184 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1185 and different variable names.
  1186 
  1187 * Library/Option_ord.thy: Canonical order on option type.
  1188 
  1189 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1190 finite maps.
  1191 
  1192 * Library/Countable.thy: Type class for countable types.
  1193 
  1194 * Theory Int: The representation of numerals has changed.  The infix
  1195 operator BIT and the bit datatype with constructors B0 and B1 have
  1196 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1197 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1198 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1199 accordingly.
  1200 
  1201 * Theory Nat: definition of <= and < on natural numbers no longer
  1202 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1203 le_def and less_def have disappeared.  Consider lemmas not_less
  1204 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1205 
  1206 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1207 (whose purpose mainly is for various fold_set functionals) have been
  1208 abandoned in favor of the existing algebraic classes
  1209 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1210 lower_semilattice (resp. upper_semilattice) and linorder.
  1211 INCOMPATIBILITY.
  1212 
  1213 * Theory Transitive_Closure: induct and cases rules now declare proper
  1214 case_names ("base" and "step").  INCOMPATIBILITY.
  1215 
  1216 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1217 lattices.  The form set-specific version is available as
  1218 Inductive.lfp_ordinal_induct_set.
  1219 
  1220 * Renamed theorems "power.simps" to "power_int.simps".
  1221 INCOMPATIBILITY.
  1222 
  1223 * Class semiring_div provides basic abstract properties of semirings
  1224 with division and modulo operations.  Subsumes former class dvd_mod.
  1225 
  1226 * Merged theories IntDef, Numeral and IntArith into unified theory
  1227 Int.  INCOMPATIBILITY.
  1228 
  1229 * Theory Library/Code_Index: type "index" now represents natural
  1230 numbers rather than integers.  INCOMPATIBILITY.
  1231 
  1232 * New class "uminus" with operation "uminus" (split of from class
  1233 "minus" which now only has operation "minus", binary).
  1234 INCOMPATIBILITY.
  1235 
  1236 * Constants "card", "internal_split", "option_map" now with authentic
  1237 syntax.  INCOMPATIBILITY.
  1238 
  1239 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1240 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1241 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1242 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1243 Sup_set_def, le_def, less_def, option_map_def now with object
  1244 equality.  INCOMPATIBILITY.
  1245 
  1246 * Records. Removed K_record, and replaced it by pure lambda term
  1247 %x. c. The simplifier setup is now more robust against eta expansion.
  1248 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1249 
  1250 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1251 
  1252 * Library/ListVector: new theory of arithmetic vector operations.
  1253 
  1254 * Library/Order_Relation: new theory of various orderings as sets of
  1255 pairs.  Defines preorders, partial orders, linear orders and
  1256 well-orders on sets and on types.
  1257 
  1258 
  1259 *** ZF ***
  1260 
  1261 * Renamed some theories to allow to loading both ZF and HOL in the
  1262 same session:
  1263 
  1264   Datatype  -> Datatype_ZF
  1265   Inductive -> Inductive_ZF
  1266   Int       -> Int_ZF
  1267   IntDiv    -> IntDiv_ZF
  1268   Nat       -> Nat_ZF
  1269   List      -> List_ZF
  1270   Main      -> Main_ZF
  1271 
  1272 INCOMPATIBILITY: ZF theories that import individual theories below
  1273 Main might need to be adapted.  Regular theory Main is still
  1274 available, as trivial extension of Main_ZF.
  1275 
  1276 
  1277 *** ML ***
  1278 
  1279 * ML within Isar: antiquotation @{const name} or @{const
  1280 name(typargs)} produces statically-checked Const term.
  1281 
  1282 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1283 (of the same name).  Removed obsolete print command.
  1284 
  1285 * Removed obsolete "use_legacy_bindings" function.
  1286 
  1287 * The ``print mode'' is now a thread-local value derived from a global
  1288 template (the former print_mode reference), thus access becomes
  1289 non-critical.  The global print_mode reference is for session
  1290 management only; user-code should use print_mode_value,
  1291 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1292 
  1293 * Functions system/system_out provide a robust way to invoke external
  1294 shell commands, with propagation of interrupts (requires Poly/ML
  1295 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1296 
  1297 
  1298 *** System ***
  1299 
  1300 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1301 in accordance with Proof General 3.7, which prefers GNU emacs.
  1302 
  1303 * isatool tty runs Isabelle process with plain tty interaction;
  1304 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1305 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1306 
  1307 * isatool browser now works with Cygwin as well, using general
  1308 "javapath" function defined in Isabelle process environment.
  1309 
  1310 * YXML notation provides a simple and efficient alternative to
  1311 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1312 isatool yxml as described in the Isabelle system manual.
  1313 
  1314 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1315 provides general wrapper for managing an Isabelle process in a robust
  1316 fashion, with ``cooked'' output from stdin/stderr.
  1317 
  1318 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1319 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1320 
  1321 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1322 way of changing the user's settings is via
  1323 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1324 script.
  1325 
  1326 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1327 cores of the underlying machine, which is a good starting point for
  1328 optimal performance tuning.  The corresponding usedir option -M allows
  1329 "max" as an alias for "0".  WARNING: does not work on certain versions
  1330 of Mac OS (with Poly/ML 5.1).
  1331 
  1332 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1333 adverse effect of Isabelle flooding interactive front-ends (notably
  1334 ProofGeneral / XEmacs).
  1335 
  1336 
  1337 
  1338 New in Isabelle2007 (November 2007)
  1339 -----------------------------------
  1340 
  1341 *** General ***
  1342 
  1343 * More uniform information about legacy features, notably a
  1344 warning/error of "Legacy feature: ...", depending on the state of the
  1345 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1346 legacy features will disappear eventually.
  1347 
  1348 * Theory syntax: the header format ``theory A = B + C:'' has been
  1349 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1350 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1351 
  1352 * Theory syntax: the old non-Isar theory file format has been
  1353 discontinued altogether.  Note that ML proof scripts may still be used
  1354 with Isar theories; migration is usually quite simple with the ML
  1355 function use_legacy_bindings.  INCOMPATIBILITY.
  1356 
  1357 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1358 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1359 quotes.
  1360 
  1361 * Theory loader: be more serious about observing the static theory
  1362 header specifications (including optional directories), but not the
  1363 accidental file locations of previously successful loads.  The strict
  1364 update policy of former update_thy is now already performed by
  1365 use_thy, so the former has been removed; use_thys updates several
  1366 theories simultaneously, just as 'imports' within a theory header
  1367 specification, but without merging the results.  Potential
  1368 INCOMPATIBILITY: may need to refine theory headers and commands
  1369 ROOT.ML which depend on load order.
  1370 
  1371 * Theory loader: optional support for content-based file
  1372 identification, instead of the traditional scheme of full physical
  1373 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1374 (cf. the system manual).  The new scheme allows to work with
  1375 non-finished theories in persistent session images, such that source
  1376 files may be moved later on without requiring reloads.
  1377 
  1378 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1379 file (with the same base name as the theory) are considered a legacy
  1380 feature, which will disappear eventually. Even now, the theory loader
  1381 no longer maintains dependencies on such files.
  1382 
  1383 * Syntax: the scope for resolving ambiguities via type-inference is
  1384 now limited to individual terms, instead of whole simultaneous
  1385 specifications as before. This greatly reduces the complexity of the
  1386 syntax module and improves flexibility by separating parsing and
  1387 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1388 'fixes' etc.) are required in rare situations.
  1389 
  1390 * Syntax: constants introduced by new-style packages ('definition',
  1391 'abbreviation' etc.) are passed through the syntax module in
  1392 ``authentic mode''. This means that associated mixfix annotations
  1393 really stick to such constants, independently of potential name space
  1394 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1395 trees are represented slightly differently, may need to adapt syntax
  1396 translations accordingly. Use CONST marker in 'translations' and
  1397 @{const_syntax} antiquotation in 'parse_translation' etc.
  1398 
  1399 * Legacy goal package: reduced interface to the bare minimum required
  1400 to keep existing proof scripts running.  Most other user-level
  1401 functions are now part of the OldGoals structure, which is *not* open
  1402 by default (consider isatool expandshort before open OldGoals).
  1403 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1404 these tend to cause confusion about the actual goal (!) context being
  1405 used here, which is not necessarily the same as the_context().
  1406 
  1407 * Command 'find_theorems': supports "*" wild-card in "name:"
  1408 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1409 support a specific search form (see ProofGeneral/CHANGES).
  1410 
  1411 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1412 by default, which means that "prems" (and also "fixed variables") are
  1413 suppressed from proof state output.  Note that the ProofGeneral
  1414 settings mechanism allows to change and save options persistently, but
  1415 older versions of Isabelle will fail to start up if a negative prems
  1416 limit is imposed.
  1417 
  1418 * Local theory targets may be specified by non-nested blocks of
  1419 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1420 contain definitions, theorems etc., including any derived mechanism
  1421 that has been implemented on top of these primitives.  This concept
  1422 generalizes the existing ``theorem (in ...)'' towards more versatility
  1423 and scalability.
  1424 
  1425 * Proof General interface: proper undo of final 'end' command;
  1426 discontinued Isabelle/classic mode (ML proof scripts).
  1427 
  1428 
  1429 *** Document preparation ***
  1430 
  1431 * Added antiquotation @{theory name} which prints the given name,
  1432 after checking that it refers to a valid ancestor theory in the
  1433 current context.
  1434 
  1435 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1436 check the given source text as ML type/structure, printing verbatim.
  1437 
  1438 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1439 "c args == rhs" given in the current context.  (Any number of
  1440 arguments may be given on the LHS.)
  1441 
  1442 
  1443 *** Pure ***
  1444 
  1445 * The 'class' package offers a combination of axclass and locale to
  1446 achieve Haskell-like type classes in Isabelle.  Definitions and
  1447 theorems within a class context produce both relative results (with
  1448 implicit parameters according to the locale context), and polymorphic
  1449 constants with qualified polymorphism (according to the class
  1450 context).  Within the body context of a 'class' target, a separate
  1451 syntax layer ("user space type system") takes care of converting
  1452 between global polymorphic consts and internal locale representation.
  1453 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1454 "isatool doc classes" provides a tutorial.
  1455 
  1456 * Generic code generator framework allows to generate executable
  1457 code for ML and Haskell (including Isabelle classes).  A short usage
  1458 sketch:
  1459 
  1460     internal compilation:
  1461         export_code <list of constants (term syntax)> in SML
  1462     writing SML code to a file:
  1463         export_code <list of constants (term syntax)> in SML <filename>
  1464     writing OCaml code to a file:
  1465         export_code <list of constants (term syntax)> in OCaml <filename>
  1466     writing Haskell code to a bunch of files:
  1467         export_code <list of constants (term syntax)> in Haskell <filename>
  1468 
  1469     evaluating closed propositions to True/False using code generation:
  1470         method ``eval''
  1471 
  1472 Reasonable default setup of framework in HOL.
  1473 
  1474 Theorem attributs for selecting and transforming function equations theorems:
  1475 
  1476     [code fun]:        select a theorem as function equation for a specific constant
  1477     [code fun del]:    deselect a theorem as function equation for a specific constant
  1478     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1479     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1480 
  1481 User-defined serializations (target in {SML, OCaml, Haskell}):
  1482 
  1483     code_const <and-list of constants (term syntax)>
  1484       {(target) <and-list of const target syntax>}+
  1485 
  1486     code_type <and-list of type constructors>
  1487       {(target) <and-list of type target syntax>}+
  1488 
  1489     code_instance <and-list of instances>
  1490       {(target)}+
  1491         where instance ::= <type constructor> :: <class>
  1492 
  1493     code_class <and_list of classes>
  1494       {(target) <and-list of class target syntax>}+
  1495         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1496 
  1497 code_instance and code_class only are effective to target Haskell.
  1498 
  1499 For example usage see src/HOL/ex/Codegenerator.thy and
  1500 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1501 generation from Isabelle/HOL theories is available via "isatool doc
  1502 codegen".
  1503 
  1504 * Code generator: consts in 'consts_code' Isar commands are now
  1505 referred to by usual term syntax (including optional type
  1506 annotations).
  1507 
  1508 * Command 'no_translations' removes translation rules from theory
  1509 syntax.
  1510 
  1511 * Overloaded definitions are now actually checked for acyclic
  1512 dependencies.  The overloading scheme is slightly more general than
  1513 that of Haskell98, although Isabelle does not demand an exact
  1514 correspondence to type class and instance declarations.
  1515 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1516 exotic versions of overloading -- at the discretion of the user!
  1517 
  1518 Polymorphic constants are represented via type arguments, i.e. the
  1519 instantiation that matches an instance against the most general
  1520 declaration given in the signature.  For example, with the declaration
  1521 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1522 as c(nat).  Overloading is essentially simultaneous structural
  1523 recursion over such type arguments.  Incomplete specification patterns
  1524 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1525 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1526 Command 'print_theory' outputs the normalized system of recursive
  1527 equations, see section "definitions".
  1528 
  1529 * Configuration options are maintained within the theory or proof
  1530 context (with name and type bool/int/string), providing a very simple
  1531 interface to a poor-man's version of general context data.  Tools may
  1532 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1533 these values using Config.get etc.  Users may change options via an
  1534 associated attribute of the same name.  This form of context
  1535 declaration works particularly well with commands 'declare' or
  1536 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1537 very easy to avoid global references, which would not observe Isar
  1538 toplevel undo/redo and fail to work with multithreading.
  1539 
  1540 Various global ML references of Pure and HOL have been turned into
  1541 configuration options:
  1542 
  1543   Unify.search_bound		unify_search_bound
  1544   Unify.trace_bound		unify_trace_bound
  1545   Unify.trace_simp		unify_trace_simp
  1546   Unify.trace_types		unify_trace_types
  1547   Simplifier.simp_depth_limit	simp_depth_limit
  1548   Blast.depth_limit		blast_depth_limit
  1549   DatatypeProp.dtK		datatype_distinctness_limit
  1550   fast_arith_neq_limit  	fast_arith_neq_limit
  1551   fast_arith_split_limit	fast_arith_split_limit
  1552 
  1553 * Named collections of theorems may be easily installed as context
  1554 data using the functor NamedThmsFun (see also
  1555 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1556 attributes; there is also a toplevel print command.  This facility is
  1557 just a common case of general context data, which is the preferred way
  1558 for anything more complex than just a list of facts in canonical
  1559 order.
  1560 
  1561 * Isar: command 'declaration' augments a local theory by generic
  1562 declaration functions written in ML.  This enables arbitrary content
  1563 being added to the context, depending on a morphism that tells the
  1564 difference of the original declaration context wrt. the application
  1565 context encountered later on.
  1566 
  1567 * Isar: proper interfaces for simplification procedures.  Command
  1568 'simproc_setup' declares named simprocs (with match patterns, and body
  1569 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1570 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1571 
  1572 * Isar: an extra pair of brackets around attribute declarations
  1573 abbreviates a theorem reference involving an internal dummy fact,
  1574 which will be ignored later --- only the effect of the attribute on
  1575 the background context will persist.  This form of in-place
  1576 declarations is particularly useful with commands like 'declare' and
  1577 'using', for example ``have A using [[simproc a]] by simp''.
  1578 
  1579 * Isar: method "assumption" (and implicit closing of subproofs) now
  1580 takes simple non-atomic goal assumptions into account: after applying
  1581 an assumption as a rule the resulting subgoals are solved by atomic
  1582 assumption steps.  This is particularly useful to finish 'obtain'
  1583 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1584 without referring to the original premise "!!x. P x ==> thesis" in the
  1585 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1586 more permissive.
  1587 
  1588 * Isar: implicit use of prems from the Isar proof context is
  1589 considered a legacy feature.  Common applications like ``have A .''
  1590 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1591 referencing facts explicitly here improves readability and
  1592 maintainability of proof texts.
  1593 
  1594 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1595 the obtained context from the course of reasoning!  For example:
  1596 
  1597   assume "EX x y. A x & B y"   -- "any previous fact"
  1598   then guess x and y by clarify
  1599 
  1600 This technique is potentially adventurous, depending on the facts and
  1601 proof tools being involved here.
  1602 
  1603 * Isar: known facts from the proof context may be specified as literal
  1604 propositions, using ASCII back-quote syntax.  This works wherever
  1605 named facts used to be allowed so far, in proof commands, proof
  1606 methods, attributes etc.  Literal facts are retrieved from the context
  1607 according to unification of type and term parameters.  For example,
  1608 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1609 theorems in the current context, then these are valid literal facts:
  1610 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1611 
  1612 There is also a proof method "fact" which does the same composition
  1613 for explicit goal states, e.g. the following proof texts coincide with
  1614 certain special cases of literal facts:
  1615 
  1616   have "A" by fact                 ==  note `A`
  1617   have "A ==> B" by fact           ==  note `A ==> B`
  1618   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1619   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1620 
  1621 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1622 outer syntax.  Thus symbolic identifiers may be used without
  1623 additional white space in declarations like this: ``assume *: A''.
  1624 
  1625 * Isar: 'print_facts' prints all local facts of the current context,
  1626 both named and unnamed ones.
  1627 
  1628 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1629 
  1630   def x == "t" and y == "u"
  1631 
  1632 * Isar: added command 'unfolding', which is structurally similar to
  1633 'using', but affects both the goal state and facts by unfolding given
  1634 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1635 'unfolded' attribute may be replaced by first-class proof text.
  1636 
  1637 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1638 and command 'unfolding' now all support object-level equalities
  1639 (potentially conditional).  The underlying notion of rewrite rule is
  1640 analogous to the 'rule_format' attribute, but *not* that of the
  1641 Simplifier (which is usually more generous).
  1642 
  1643 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1644 premises of a theorem by n. Useful in conjunction with drule.
  1645 
  1646 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1647 method expression within a sandbox consisting of the first N
  1648 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1649 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1650 simplifies all new goals that emerge from applying rule foo to the
  1651 originally first one.
  1652 
  1653 * Isar: schematic goals are no longer restricted to higher-order
  1654 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1655 expected.
  1656 
  1657 * Isar: the conclusion of a long theorem statement is now either
  1658 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1659 (essentially a disjunction of cases with local parameters and
  1660 assumptions).  The latter allows to express general elimination rules
  1661 adequately; in this notation common elimination rules look like this:
  1662 
  1663   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1664     assumes "EX x. P x"
  1665     obtains x where "P x"
  1666 
  1667   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1668     assumes "A & B"
  1669     obtains A and B
  1670 
  1671   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1672     assumes "A | B"
  1673     obtains
  1674       A
  1675     | B
  1676 
  1677 The subsequent classical rules even refer to the formal "thesis"
  1678 explicitly:
  1679 
  1680   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1681     obtains "~ thesis"
  1682 
  1683   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1684     obtains "thesis ==> something"
  1685 
  1686 The actual proof of an 'obtains' statement is analogous to that of the
  1687 Isar proof element 'obtain', only that there may be several cases.
  1688 Optional case names may be specified in parentheses; these will be
  1689 available both in the present proof and as annotations in the
  1690 resulting rule, for later use with the 'cases' method (cf. attribute
  1691 case_names).
  1692 
  1693 * Isar: the assumptions of a long theorem statement are available as
  1694 "assms" fact in the proof context.  This is more appropriate than the
  1695 (historical) "prems", which refers to all assumptions of the current
  1696 context, including those from the target locale, proof body etc.
  1697 
  1698 * Isar: 'print_statement' prints theorems from the current theory or
  1699 proof context in long statement form, according to the syntax of a
  1700 top-level lemma.
  1701 
  1702 * Isar: 'obtain' takes an optional case name for the local context
  1703 introduction rule (default "that").
  1704 
  1705 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1706 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1707 to occur.
  1708 
  1709 * Pure: syntax "CONST name" produces a fully internalized constant
  1710 according to the current context.  This is particularly useful for
  1711 syntax translations that should refer to internal constant
  1712 representations independently of name spaces.
  1713 
  1714 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1715 instead of "FOO ". This allows multiple binder declarations to coexist
  1716 in the same context.  INCOMPATIBILITY.
  1717 
  1718 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1719 primitive that also works in a locale context (both for constants and
  1720 fixed variables). Type declaration and internal syntactic representation
  1721 of given constants retrieved from the context. Likewise, the
  1722 'no_notation' command allows to remove given syntax annotations from the
  1723 current context.
  1724 
  1725 * Isar/locales: new derived specification elements 'axiomatization',
  1726 'definition', 'abbreviation', which support type-inference, admit
  1727 object-level specifications (equality, equivalence).  See also the
  1728 isar-ref manual.  Examples:
  1729 
  1730   axiomatization
  1731     eq  (infix "===" 50) where
  1732     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1733 
  1734   definition "f x y = x + y + 1"
  1735   definition g where "g x = f x x"
  1736 
  1737   abbreviation
  1738     neq  (infix "=!=" 50) where
  1739     "x =!= y == ~ (x === y)"
  1740 
  1741 These specifications may be also used in a locale context.  Then the
  1742 constants being introduced depend on certain fixed parameters, and the
  1743 constant name is qualified by the locale base name.  An internal
  1744 abbreviation takes care for convenient input and output, making the
  1745 parameters implicit and using the original short name.  See also
  1746 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1747 entities from a monomorphic theory.
  1748 
  1749 Presently, abbreviations are only available 'in' a target locale, but
  1750 not inherited by general import expressions.  Also note that
  1751 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1752 'translations' in common applications.  The "no_abbrevs" print mode
  1753 prevents folding of abbreviations in term output.
  1754 
  1755 Concrete syntax is attached to specified constants in internal form,
  1756 independently of name spaces.  The parse tree representation is
  1757 slightly different -- use 'notation' instead of raw 'syntax', and
  1758 'translations' with explicit "CONST" markup to accommodate this.
  1759 
  1760 * Pure/Isar: unified syntax for new-style specification mechanisms
  1761 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1762 full type inference and dummy patterns ("_").  For example:
  1763 
  1764   definition "K x _ = x"
  1765 
  1766   inductive conj for A B
  1767   where "A ==> B ==> conj A B"
  1768 
  1769 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1770 the current context.  Print mode "no_abbrevs" prevents inversion of
  1771 abbreviations on output.
  1772 
  1773 * Isar/locales: improved parameter handling: use of locales "var" and
  1774 "struct" no longer necessary; - parameter renamings are no longer
  1775 required to be injective.  For example, this allows to define
  1776 endomorphisms as locale endom = homom mult mult h.
  1777 
  1778 * Isar/locales: changed the way locales with predicates are defined.
  1779 Instead of accumulating the specification, the imported expression is
  1780 now an interpretation.  INCOMPATIBILITY: different normal form of
  1781 locale expressions.  In particular, in interpretations of locales with
  1782 predicates, goals repesenting already interpreted fragments are not
  1783 removed automatically.  Use methods `intro_locales' and
  1784 `unfold_locales'; see below.
  1785 
  1786 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1787 provide backward reasoning on locales predicates.  The methods are
  1788 aware of interpretations and discharge corresponding goals.
  1789 `intro_locales' is less aggressive then `unfold_locales' and does not
  1790 unfold predicates to assumptions.
  1791 
  1792 * Isar/locales: the order in which locale fragments are accumulated
  1793 has changed.  This enables to override declarations from fragments due
  1794 to interpretations -- for example, unwanted simp rules.
  1795 
  1796 * Isar/locales: interpretation in theories and proof contexts has been
  1797 extended.  One may now specify (and prove) equations, which are
  1798 unfolded in interpreted theorems.  This is useful for replacing
  1799 defined concepts (constants depending on locale parameters) by
  1800 concepts already existing in the target context.  Example:
  1801 
  1802   interpretation partial_order ["op <= :: [int, int] => bool"]
  1803     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1804 
  1805 Typically, the constant `partial_order.less' is created by a
  1806 definition specification element in the context of locale
  1807 partial_order.
  1808 
  1809 * Method "induct": improved internal context management to support
  1810 local fixes and defines on-the-fly. Thus explicit meta-level
  1811 connectives !!  and ==> are rarely required anymore in inductive goals
  1812 (using object-logic connectives for this purpose has been long
  1813 obsolete anyway). Common proof patterns are explained in
  1814 src/HOL/Induct/Common_Patterns.thy, see also
  1815 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1816 examples.
  1817 
  1818 * Method "induct": improved handling of simultaneous goals. Instead of
  1819 introducing object-level conjunction, the statement is now split into
  1820 several conclusions, while the corresponding symbolic cases are nested
  1821 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1822 see src/HOL/Induct/Common_Patterns.thy, for example.
  1823 
  1824 * Method "induct": mutual induction rules are now specified as a list
  1825 of rule sharing the same induction cases. HOL packages usually provide
  1826 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1827 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1828 mutual induction rules differently, i.e. like this:
  1829 
  1830   (induct rule: foo_bar.inducts)
  1831   (induct set: foo bar)
  1832   (induct pred: foo bar)
  1833   (induct type: foo bar)
  1834 
  1835 The ML function ProjectRule.projections turns old-style rules into the
  1836 new format.
  1837 
  1838 * Method "coinduct": dual of induction, see
  1839 src/HOL/Library/Coinductive_List.thy for various examples.
  1840 
  1841 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1842 considered a legacy feature.
  1843 
  1844 * Attribute "symmetric" produces result with standardized schematic
  1845 variables (index 0).  Potential INCOMPATIBILITY.
  1846 
  1847 * Simplifier: by default the simplifier trace only shows top level
  1848 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1849 default. Thus there is less danger of being flooded by the trace. The
  1850 trace indicates where parts have been suppressed.
  1851   
  1852 * Provers/classical: removed obsolete classical version of elim_format
  1853 attribute; classical elim/dest rules are now treated uniformly when
  1854 manipulating the claset.
  1855 
  1856 * Provers/classical: stricter checks to ensure that supplied intro,
  1857 dest and elim rules are well-formed; dest and elim rules must have at
  1858 least one premise.
  1859 
  1860 * Provers/classical: attributes dest/elim/intro take an optional
  1861 weight argument for the rule (just as the Pure versions).  Weights are
  1862 ignored by automated tools, but determine the search order of single
  1863 rule steps.
  1864 
  1865 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1866 where the body does not mention the bound variable.  Note that dummy
  1867 patterns implicitly depend on their context of bounds, which makes
  1868 "{_. _}" match any set comprehension as expected.  Potential
  1869 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1870 constant "_idtdummy" in the binding position.
  1871 
  1872 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1873 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1874 for example "A -> B" => "Pi A (%_. B)".
  1875 
  1876 * Pure: 'class_deps' command visualizes the subclass relation, using
  1877 the graph browser tool.
  1878 
  1879 * Pure: 'print_theory' now suppresses certain internal declarations by
  1880 default; use '!' option for full details.
  1881 
  1882 
  1883 *** HOL ***
  1884 
  1885 * Method "metis" proves goals by applying the Metis general-purpose
  1886 resolution prover (see also http://gilith.com/software/metis/).
  1887 Examples are in the directory MetisExamples.  WARNING: the
  1888 Isabelle/HOL-Metis integration does not yet work properly with
  1889 multi-threading.
  1890   
  1891 * Command 'sledgehammer' invokes external automatic theorem provers as
  1892 background processes.  It generates calls to the "metis" method if
  1893 successful. These can be pasted into the proof.  Users do not have to
  1894 wait for the automatic provers to return.  WARNING: does not really
  1895 work with multi-threading.
  1896 
  1897 * New "auto_quickcheck" feature tests outermost goal statements for
  1898 potential counter-examples.  Controlled by ML references
  1899 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  1900 5000 milliseconds).  Fails silently if statements is outside of
  1901 executable fragment, or any other codgenerator problem occurs.
  1902 
  1903 * New constant "undefined" with axiom "undefined x = undefined".
  1904 
  1905 * Added class "HOL.eq", allowing for code generation with polymorphic
  1906 equality.
  1907 
  1908 * Some renaming of class constants due to canonical name prefixing in
  1909 the new 'class' package:
  1910 
  1911     HOL.abs ~> HOL.abs_class.abs
  1912     HOL.divide ~> HOL.divide_class.divide
  1913     0 ~> HOL.zero_class.zero
  1914     1 ~> HOL.one_class.one
  1915     op + ~> HOL.plus_class.plus
  1916     op - ~> HOL.minus_class.minus
  1917     uminus ~> HOL.minus_class.uminus
  1918     op * ~> HOL.times_class.times
  1919     op < ~> HOL.ord_class.less
  1920     op <= > HOL.ord_class.less_eq
  1921     Nat.power ~> Power.power_class.power
  1922     Nat.size ~> Nat.size_class.size
  1923     Numeral.number_of ~> Numeral.number_class.number_of
  1924     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  1925     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  1926     Orderings.min ~> Orderings.ord_class.min
  1927     Orderings.max ~> Orderings.ord_class.max
  1928     Divides.op div ~> Divides.div_class.div
  1929     Divides.op mod ~> Divides.div_class.mod
  1930     Divides.op dvd ~> Divides.div_class.dvd
  1931 
  1932 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  1933 
  1934 a) User-defined constants using any of the names "plus", "minus",
  1935 "times", "less" or "less_eq". The standard syntax translations for
  1936 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1937 names.
  1938 
  1939 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1940 INCOMPATIBILITY: use more specific names.
  1941 
  1942 c) Permutative equations (e.g. "a + b = b + a")
  1943 Since the change of names also changes the order of terms, permutative
  1944 rewrite rules may get applied in a different order. Experience shows
  1945 that this is rarely the case (only two adaptions in the whole Isabelle
  1946 distribution).  INCOMPATIBILITY: rewrite proofs
  1947 
  1948 d) ML code directly refering to constant names
  1949 This in general only affects hand-written proof tactics, simprocs and
  1950 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1951 Consider using @{const_name} antiquotation.
  1952 
  1953 * New class "default" with associated constant "default".
  1954 
  1955 * Function "sgn" is now overloaded and available on int, real, complex
  1956 (and other numeric types), using class "sgn".  Two possible defs of
  1957 sgn are given as equational assumptions in the classes sgn_if and
  1958 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  1959 INCOMPATIBILITY.
  1960 
  1961 * Locale "partial_order" now unified with class "order" (cf. theory
  1962 Orderings), added parameter "less".  INCOMPATIBILITY.
  1963 
  1964 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  1965 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  1966 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  1967 
  1968 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  1969 changed order of proof goals in instance proofs.
  1970 
  1971 * The transitivity reasoner for partial and linear orders is set up
  1972 for classes "order" and "linorder".  Instances of the reasoner are available
  1973 in all contexts importing or interpreting the corresponding locales.
  1974 Method "order" invokes the reasoner separately; the reasoner
  1975 is also integrated with the Simplifier as a solver.  Diagnostic
  1976 command 'print_orders' shows the available instances of the reasoner
  1977 in the current context.
  1978 
  1979 * Localized monotonicity predicate in theory "Orderings"; integrated
  1980 lemmas max_of_mono and min_of_mono with this predicate.
  1981 INCOMPATIBILITY.
  1982 
  1983 * Formulation of theorem "dense" changed slightly due to integration
  1984 with new class dense_linear_order.
  1985 
  1986 * Uniform lattice theory development in HOL.
  1987 
  1988     constants "meet" and "join" now named "inf" and "sup"
  1989     constant "Meet" now named "Inf"
  1990 
  1991     classes "meet_semilorder" and "join_semilorder" now named
  1992       "lower_semilattice" and "upper_semilattice"
  1993     class "lorder" now named "lattice"
  1994     class "comp_lat" now named "complete_lattice"
  1995 
  1996     Instantiation of lattice classes allows explicit definitions
  1997     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  1998 
  1999   INCOMPATIBILITY.  Theorem renames:
  2000 
  2001     meet_left_le            ~> inf_le1
  2002     meet_right_le           ~> inf_le2
  2003     join_left_le            ~> sup_ge1
  2004     join_right_le           ~> sup_ge2
  2005     meet_join_le            ~> inf_sup_ord
  2006     le_meetI                ~> le_infI
  2007     join_leI                ~> le_supI
  2008     le_meet                 ~> le_inf_iff
  2009     le_join                 ~> ge_sup_conv
  2010     meet_idempotent         ~> inf_idem
  2011     join_idempotent         ~> sup_idem
  2012     meet_comm               ~> inf_commute
  2013     join_comm               ~> sup_commute
  2014     meet_leI1               ~> le_infI1
  2015     meet_leI2               ~> le_infI2
  2016     le_joinI1               ~> le_supI1
  2017     le_joinI2               ~> le_supI2
  2018     meet_assoc              ~> inf_assoc
  2019     join_assoc              ~> sup_assoc
  2020     meet_left_comm          ~> inf_left_commute
  2021     meet_left_idempotent    ~> inf_left_idem
  2022     join_left_comm          ~> sup_left_commute
  2023     join_left_idempotent    ~> sup_left_idem
  2024     meet_aci                ~> inf_aci
  2025     join_aci                ~> sup_aci
  2026     le_def_meet             ~> le_iff_inf
  2027     le_def_join             ~> le_iff_sup
  2028     join_absorp2            ~> sup_absorb2
  2029     join_absorp1            ~> sup_absorb1
  2030     meet_absorp1            ~> inf_absorb1
  2031     meet_absorp2            ~> inf_absorb2
  2032     meet_join_absorp        ~> inf_sup_absorb
  2033     join_meet_absorp        ~> sup_inf_absorb
  2034     distrib_join_le         ~> distrib_sup_le
  2035     distrib_meet_le         ~> distrib_inf_le
  2036 
  2037     add_meet_distrib_left   ~> add_inf_distrib_left
  2038     add_join_distrib_left   ~> add_sup_distrib_left
  2039     is_join_neg_meet        ~> is_join_neg_inf
  2040     is_meet_neg_join        ~> is_meet_neg_sup
  2041     add_meet_distrib_right  ~> add_inf_distrib_right
  2042     add_join_distrib_right  ~> add_sup_distrib_right
  2043     add_meet_join_distribs  ~> add_sup_inf_distribs
  2044     join_eq_neg_meet        ~> sup_eq_neg_inf
  2045     meet_eq_neg_join        ~> inf_eq_neg_sup
  2046     add_eq_meet_join        ~> add_eq_inf_sup
  2047     meet_0_imp_0            ~> inf_0_imp_0
  2048     join_0_imp_0            ~> sup_0_imp_0
  2049     meet_0_eq_0             ~> inf_0_eq_0
  2050     join_0_eq_0             ~> sup_0_eq_0
  2051     neg_meet_eq_join        ~> neg_inf_eq_sup
  2052     neg_join_eq_meet        ~> neg_sup_eq_inf
  2053     join_eq_if              ~> sup_eq_if
  2054 
  2055     mono_meet               ~> mono_inf
  2056     mono_join               ~> mono_sup
  2057     meet_bool_eq            ~> inf_bool_eq
  2058     join_bool_eq            ~> sup_bool_eq
  2059     meet_fun_eq             ~> inf_fun_eq
  2060     join_fun_eq             ~> sup_fun_eq
  2061     meet_set_eq             ~> inf_set_eq
  2062     join_set_eq             ~> sup_set_eq
  2063     meet1_iff               ~> inf1_iff
  2064     meet2_iff               ~> inf2_iff
  2065     meet1I                  ~> inf1I
  2066     meet2I                  ~> inf2I
  2067     meet1D1                 ~> inf1D1
  2068     meet2D1                 ~> inf2D1
  2069     meet1D2                 ~> inf1D2
  2070     meet2D2                 ~> inf2D2
  2071     meet1E                  ~> inf1E
  2072     meet2E                  ~> inf2E
  2073     join1_iff               ~> sup1_iff
  2074     join2_iff               ~> sup2_iff
  2075     join1I1                 ~> sup1I1
  2076     join2I1                 ~> sup2I1
  2077     join1I1                 ~> sup1I1
  2078     join2I2                 ~> sup1I2
  2079     join1CI                 ~> sup1CI
  2080     join2CI                 ~> sup2CI
  2081     join1E                  ~> sup1E
  2082     join2E                  ~> sup2E
  2083 
  2084     is_meet_Meet            ~> is_meet_Inf
  2085     Meet_bool_def           ~> Inf_bool_def
  2086     Meet_fun_def            ~> Inf_fun_def
  2087     Meet_greatest           ~> Inf_greatest
  2088     Meet_lower              ~> Inf_lower
  2089     Meet_set_def            ~> Inf_set_def
  2090 
  2091     Sup_def                 ~> Sup_Inf
  2092     Sup_bool_eq             ~> Sup_bool_def
  2093     Sup_fun_eq              ~> Sup_fun_def
  2094     Sup_set_eq              ~> Sup_set_def
  2095 
  2096     listsp_meetI            ~> listsp_infI
  2097     listsp_meet_eq          ~> listsp_inf_eq
  2098 
  2099     meet_min                ~> inf_min
  2100     join_max                ~> sup_max
  2101 
  2102 * Added syntactic class "size"; overloaded constant "size" now has
  2103 type "'a::size ==> bool"
  2104 
  2105 * Internal reorganisation of `size' of datatypes: size theorems
  2106 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2107 simplification rules by default!); theorems "prod.size" now named
  2108 "*.size".
  2109 
  2110 * Class "div" now inherits from class "times" rather than "type".
  2111 INCOMPATIBILITY.
  2112 
  2113 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2114 Linorder etc.  have disappeared; operations defined in terms of
  2115 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2116 
  2117 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2118 
  2119 * HOL-Word: New extensive library and type for generic, fixed size
  2120 machine words, with arithemtic, bit-wise, shifting and rotating
  2121 operations, reflection into int, nat, and bool lists, automation for
  2122 linear arithmetic (by automatic reflection into nat or int), including
  2123 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2124 arithmetic type classes, supporting automatic simplification of
  2125 numerals on all operations.
  2126 
  2127 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2128 
  2129 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2130 
  2131 * Code generator library theories:
  2132   - Code_Integer represents HOL integers by big integer literals in target
  2133     languages.
  2134   - Code_Char represents HOL characters by character literals in target
  2135     languages.
  2136   - Code_Char_chr like Code_Char, but also offers treatment of character
  2137     codes; includes Code_Integer.
  2138   - Executable_Set allows to generate code for finite sets using lists.
  2139   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2140     denominator).
  2141   - Executable_Real implements a subset of real numbers, namly those
  2142     representable by rational numbers.
  2143   - Efficient_Nat implements natural numbers by integers, which in general will
  2144     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2145     includes Code_Integer.
  2146   - Code_Index provides an additional datatype index which is mapped to
  2147     target-language built-in integers.
  2148   - Code_Message provides an additional datatype message_string which is isomorphic to
  2149     strings; messages are mapped to target-language strings.
  2150 
  2151 * New package for inductive predicates
  2152 
  2153   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2154 
  2155     inductive
  2156       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2157       for z_1 :: U_1 and ... and z_n :: U_m
  2158     where
  2159       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2160     | ...
  2161 
  2162   with full support for type-inference, rather than
  2163 
  2164     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2165 
  2166     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2167     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2168 
  2169     inductive "s z_1 ... z_m"
  2170     intros
  2171       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2172       ...
  2173 
  2174   For backward compatibility, there is a wrapper allowing inductive
  2175   sets to be defined with the new package via
  2176 
  2177     inductive_set
  2178       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2179       for z_1 :: U_1 and ... and z_n :: U_m
  2180     where
  2181       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2182     | ...
  2183 
  2184   or
  2185 
  2186     inductive_set
  2187       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2188       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2189       for z_1 :: U_1 and ... and z_n :: U_m
  2190     where
  2191       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2192     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2193     | ...
  2194 
  2195   if the additional syntax "p ..." is required.
  2196 
  2197   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2198   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2199 
  2200   INCOMPATIBILITIES:
  2201 
  2202   - Since declaration and definition of inductive sets or predicates
  2203     is no longer separated, abbreviations involving the newly
  2204     introduced sets or predicates must be specified together with the
  2205     introduction rules after the 'where' keyword (see above), rather
  2206     than before the actual inductive definition.
  2207 
  2208   - The variables in induction and elimination rules are now
  2209     quantified in the order of their occurrence in the introduction
  2210     rules, rather than in alphabetical order. Since this may break
  2211     some proofs, these proofs either have to be repaired, e.g. by
  2212     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2213     statements of the form
  2214 
  2215       case (rule_i a_i_1 ... a_i_{k_i})
  2216 
  2217     or the old order of quantification has to be restored by explicitly adding
  2218     meta-level quantifiers in the introduction rules, i.e.
  2219 
  2220       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2221 
  2222   - The format of the elimination rules is now
  2223 
  2224       p z_1 ... z_m x_1 ... x_n ==>
  2225         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2226         ==> ... ==> P
  2227 
  2228     for predicates and
  2229 
  2230       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2231         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2232         ==> ... ==> P
  2233 
  2234     for sets rather than
  2235 
  2236       x : s z_1 ... z_m ==>
  2237         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2238         ==> ... ==> P
  2239 
  2240     This may require terms in goals to be expanded to n-tuples
  2241     (e.g. using case_tac or simplification with the split_paired_all
  2242     rule) before the above elimination rule is applicable.
  2243 
  2244   - The elimination or case analysis rules for (mutually) inductive
  2245     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2246     list of rules "p_1_..._p_k.elims" is no longer available.
  2247 
  2248 * New package "function"/"fun" for general recursive functions,
  2249 supporting mutual and nested recursion, definitions in local contexts,
  2250 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2251 for small examples, and the separate tutorial on the function
  2252 package. The old recdef "package" is still available as before, but
  2253 users are encouraged to use the new package.
  2254 
  2255 * Method "lexicographic_order" automatically synthesizes termination
  2256 relations as lexicographic combinations of size measures. 
  2257 
  2258 * Case-expressions allow arbitrary constructor-patterns (including
  2259 "_") and take their order into account, like in functional
  2260 programming.  Internally, this is translated into nested
  2261 case-expressions; missing cases are added and mapped to the predefined
  2262 constant "undefined". In complicated cases printing may no longer show
  2263 the original input but the internal form. Lambda-abstractions allow
  2264 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2265 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2266 variable.
  2267 
  2268 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2269 is an abbreviation for "of_nat :: nat => int". The simplification
  2270 rules for "of_nat" have been changed to work like "int" did
  2271 previously.  Potential INCOMPATIBILITY:
  2272   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2273   - of_nat_diff and of_nat_mult are no longer default simp rules
  2274 
  2275 * Method "algebra" solves polynomial equations over (semi)rings using
  2276 Groebner bases. The (semi)ring structure is defined by locales and the
  2277 tool setup depends on that generic context. Installing the method for
  2278 a specific type involves instantiating the locale and possibly adding
  2279 declarations for computation on the coefficients.  The method is
  2280 already instantiated for natural numbers and for the axiomatic class
  2281 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2282 CALCULEMUS 2007 for the general principles underlying this
  2283 architecture of context-aware proof-tools.
  2284 
  2285 * Method "ferrack" implements quantifier elimination over
  2286 special-purpose dense linear orders using locales (analogous to
  2287 "algebra"). The method is already installed for class
  2288 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2289 rat, etc.
  2290 
  2291 * Former constant "List.op @" now named "List.append".  Use ML
  2292 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2293 circumvent possible incompatibilities when working on ML level.
  2294 
  2295 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2296 
  2297 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2298 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2299 
  2300 * New syntax for Haskell-like list comprehension (input only), eg.
  2301 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2302 
  2303 * The special syntax for function "filter" has changed from [x :
  2304 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2305 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2306 
  2307 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2308 defined on nat only, as an abbreviation for [a..<Suc b]
  2309 INCOMPATIBILITY.
  2310 
  2311 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2312 
  2313 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2314 
  2315 * New lemma collection field_simps (an extension of ring_simps) for
  2316 manipulating (in)equations involving division. Multiplies with all
  2317 denominators that can be proved to be non-zero (in equations) or
  2318 positive/negative (in inequations).
  2319 
  2320 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2321 have been improved and renamed to ring_simps, group_simps and
  2322 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2323 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2324 
  2325 * Theory Library/Commutative_Ring: switched from recdef to function
  2326 package; constants add, mul, pow now curried.  Infix syntax for
  2327 algebraic operations.
  2328 
  2329 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2330 INCOMPATIBILITY.
  2331 
  2332 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2333 INCOMPATIBILITY.
  2334 
  2335 * HOL/records: generalised field-update to take a function on the
  2336 field rather than the new value: r(|A := x|) is translated to A_update
  2337 (K x) r The K-combinator that is internally used is called K_record.
  2338 INCOMPATIBILITY: Usage of the plain update functions has to be
  2339 adapted.
  2340  
  2341 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2342 * x = 0, which are required for a semiring.  Richer structures do not
  2343 inherit from semiring_0 anymore, because this property is a theorem
  2344 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2345 there is more to prove, but this is mostly trivial.
  2346 
  2347 * Class "recpower" is generalized to arbitrary monoids, not just
  2348 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2349 commutativity or semiring properties additionally.
  2350 
  2351 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2352 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2353 better use 'abbreviation'.
  2354 
  2355 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2356 
  2357 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2358 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2359 significant changes for setting up numeral syntax for types:
  2360   - New constants Numeral.pred and Numeral.succ instead
  2361       of former Numeral.bin_pred and Numeral.bin_succ.
  2362   - Use integer operations instead of bin_add, bin_mult and so on.
  2363   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2364   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2365 
  2366 See src/HOL/Integ/IntArith.thy for an example setup.
  2367 
  2368 * Command 'normal_form' computes the normal form of a term that may
  2369 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2370 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2371 heavy-duty computations because the functions are compiled to ML
  2372 first.  Correspondingly, a method "normalization" is provided.  See
  2373 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2374 
  2375 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2376 25 like -->); output depends on the "iff" print_mode, the default is
  2377 "A = B" (with priority 50).
  2378 
  2379 * Relations less (<) and less_eq (<=) are also available on type bool.
  2380 Modified syntax to disallow nesting without explicit parentheses,
  2381 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2382 INCOMPATIBILITY.
  2383 
  2384 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2385 
  2386 * Relation composition operator "op O" now has precedence 75 and binds
  2387 stronger than union and intersection. INCOMPATIBILITY.
  2388 
  2389 * The old set interval syntax "{m..n(}" (and relatives) has been
  2390 removed.  Use "{m..<n}" (and relatives) instead.
  2391 
  2392 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2393 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2394 ``declare [[simproc del: neq]]''.
  2395 
  2396 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2397 True/False.
  2398 
  2399 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2400 
  2401 * Theorem setsum_mult renamed to setsum_right_distrib.
  2402 
  2403 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2404 ``rule'' method.
  2405 
  2406 * Reimplemented methods "sat" and "satx", with several improvements:
  2407 goals no longer need to be stated as "<prems> ==> False", equivalences
  2408 (i.e. "=" on type bool) are handled, variable names of the form
  2409 "lit_<n>" are no longer reserved, significant speedup.
  2410 
  2411 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2412 zChaff is still supported as well.
  2413 
  2414 * 'inductive' and 'datatype': provide projections of mutual rules,
  2415 bundled as foo_bar.inducts;
  2416 
  2417 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2418 Library.
  2419 
  2420 * Library: moved theory Accessible_Part to main HOL.
  2421 
  2422 * Library: added theory Coinductive_List of potentially infinite lists
  2423 as greatest fixed-point.
  2424 
  2425 * Library: added theory AssocList which implements (finite) maps as
  2426 association lists.
  2427 
  2428 * Method "evaluation" solves goals (i.e. a boolean expression)
  2429 efficiently by compiling it to ML.  The goal is "proved" (via an
  2430 oracle) if it evaluates to True.
  2431 
  2432 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2433 also when invoked by the simplifier.  This results in the Simplifier
  2434 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2435 Configuration option fast_arith_split_limit=0 recovers the old
  2436 behavior.
  2437 
  2438 * Support for hex (0x20) and binary (0b1001) numerals.
  2439 
  2440 * New method: reify eqs (t), where eqs are equations for an
  2441 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2442 parameter, computes a term s::'b and a list xs::'a list and proves the
  2443 theorem I xs s = t. This is also known as reification or quoting. The
  2444 resulting theorem is applied to the subgoal to substitute t with I xs
  2445 s.  If t is omitted, the subgoal itself is reified.
  2446 
  2447 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2448 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2449 where f is supposed to be a computable function (in the sense of code
  2450 generattion). The method uses reify to compute s and xs as above then
  2451 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2452 r and finally gets the theorem t = r, which is again applied to the
  2453 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2454 
  2455 * Reflection: Automatic reification now handels binding, an example is
  2456 available in src/HOL/ex/ReflectionEx.thy
  2457 
  2458 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2459 command 'statespace' that is similar to 'record', but introduces an
  2460 abstract specification based on the locale infrastructure instead of
  2461 HOL types.  This leads to extra flexibility in composing state spaces,
  2462 in particular multiple inheritance and renaming of components.
  2463 
  2464 
  2465 *** HOL-Complex ***
  2466 
  2467 * Hyperreal: Functions root and sqrt are now defined on negative real
  2468 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2469 Nonnegativity side conditions have been removed from many lemmas, so
  2470 that more subgoals may now be solved by simplification; potential
  2471 INCOMPATIBILITY.
  2472 
  2473 * Real: new type classes formalize real normed vector spaces and
  2474 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2475 and norm :: 'a => real.
  2476 
  2477 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2478 reals into other types. The overloaded constant Reals :: 'a set is now
  2479 defined as range of_real; potential INCOMPATIBILITY.
  2480 
  2481 * Real: proper support for ML code generation, including 'quickcheck'.
  2482 Reals are implemented as arbitrary precision rationals.
  2483 
  2484 * Hyperreal: Several constants that previously worked only for the
  2485 reals have been generalized, so they now work over arbitrary vector
  2486 spaces. Type annotations may need to be added in some cases; potential
  2487 INCOMPATIBILITY.
  2488 
  2489   Infinitesimal  :: ('a::real_normed_vector) star set
  2490   HFinite        :: ('a::real_normed_vector) star set
  2491   HInfinite      :: ('a::real_normed_vector) star set
  2492   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2493   monad          :: ('a::real_normed_vector) star => 'a star set
  2494   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2495   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2496   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2497   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2498   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2499   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2500   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2501   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2502   sgn            :: 'a::real_normed_vector => 'a
  2503   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2504 
  2505 * Complex: Some complex-specific constants are now abbreviations for
  2506 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2507 hnorm.  Other constants have been entirely removed in favor of the
  2508 polymorphic versions (INCOMPATIBILITY):
  2509 
  2510   approx        <-- capprox
  2511   HFinite       <-- CFinite
  2512   HInfinite     <-- CInfinite
  2513   Infinitesimal <-- CInfinitesimal
  2514   monad         <-- cmonad
  2515   galaxy        <-- cgalaxy
  2516   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2517   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2518   (ns)deriv     <-- (ns)cderiv
  2519 
  2520 
  2521 *** HOL-Algebra ***
  2522 
  2523 * Formalisation of ideals and the quotient construction over rings.
  2524 
  2525 * Order and lattice theory no longer based on records.
  2526 INCOMPATIBILITY.
  2527 
  2528 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2529 greatest_closed.  INCOMPATIBILITY.
  2530 
  2531 * Method algebra is now set up via an attribute.  For examples see
  2532 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2533 of algebraic structures.
  2534 
  2535 * Renamed theory CRing to Ring.
  2536 
  2537 
  2538 *** HOL-Nominal ***
  2539 
  2540 * Substantial, yet incomplete support for nominal datatypes (binding
  2541 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2542 src/HOL/Nominal/Examples.  Prospective users should consult
  2543 http://isabelle.in.tum.de/nominal/
  2544 
  2545 
  2546 *** ML ***
  2547 
  2548 * ML basics: just one true type int, which coincides with IntInf.int
  2549 (even on SML/NJ).
  2550 
  2551 * ML within Isar: antiquotations allow to embed statically-checked
  2552 formal entities in the source, referring to the context available at
  2553 compile-time.  For example:
  2554 
  2555 ML {* @{sort "{zero,one}"} *}
  2556 ML {* @{typ "'a => 'b"} *}
  2557 ML {* @{term "%x. x"} *}
  2558 ML {* @{prop "x == y"} *}
  2559 ML {* @{ctyp "'a => 'b"} *}
  2560 ML {* @{cterm "%x. x"} *}
  2561 ML {* @{cprop "x == y"} *}
  2562 ML {* @{thm asm_rl} *}
  2563 ML {* @{thms asm_rl} *}
  2564 ML {* @{type_name c} *}
  2565 ML {* @{type_syntax c} *}
  2566 ML {* @{const_name c} *}
  2567 ML {* @{const_syntax c} *}
  2568 ML {* @{context} *}
  2569 ML {* @{theory} *}
  2570 ML {* @{theory Pure} *}
  2571 ML {* @{theory_ref} *}
  2572 ML {* @{theory_ref Pure} *}
  2573 ML {* @{simpset} *}
  2574 ML {* @{claset} *}
  2575 ML {* @{clasimpset} *}
  2576 
  2577 The same works for sources being ``used'' within an Isar context.
  2578 
  2579 * ML in Isar: improved error reporting; extra verbosity with
  2580 ML_Context.trace enabled.
  2581 
  2582 * Pure/General/table.ML: the join operations now works via exceptions
  2583 DUP/SAME instead of type option. This is simpler in simple cases, and
  2584 admits slightly more efficient complex applications.
  2585 
  2586 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2587 use Context.generic instead of just theory.
  2588 
  2589 * Pure: datatype Context.generic joins theory/Proof.context and
  2590 provides some facilities for code that works in either kind of
  2591 context, notably GenericDataFun for uniform theory and proof data.
  2592 
  2593 * Pure: simplified internal attribute type, which is now always
  2594 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2595 local (Proof.context) attributes have been discontinued, while
  2596 minimizing code duplication. Thm.rule_attribute and
  2597 Thm.declaration_attribute build canonical attributes; see also structure
  2598 Context for further operations on Context.generic, notably
  2599 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2600 declarations and definitions.
  2601 
  2602 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2603 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2604 init only required for impure data. INCOMPATIBILITY: empty really need
  2605 to be empty (no dependencies on theory content!)
  2606 
  2607 * Pure/kernel: consts certification ignores sort constraints given in
  2608 signature declarations. (This information is not relevant to the
  2609 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2610 potential INCOMPATIBILITY.
  2611 
  2612 * Pure: axiomatic type classes are now purely definitional, with
  2613 explicit proofs of class axioms and super class relations performed
  2614 internally. See Pure/axclass.ML for the main internal interfaces --
  2615 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2616 AxClass.axiomatize_class/classrel/arity supersede
  2617 Sign.add_classes/classrel/arities.
  2618 
  2619 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2620 global/local versions on theory vs. Proof.context have been
  2621 discontinued; Attrib.syntax and Method.syntax have been adapted
  2622 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2623 attributes, methods, etc.
  2624 
  2625 * Pure: several functions of signature "... -> theory -> theory * ..."
  2626 have been reoriented to "... -> theory -> ... * theory" in order to
  2627 allow natural usage in combination with the ||>, ||>>, |-> and
  2628 fold_map combinators.
  2629 
  2630 * Pure: official theorem names (closed derivations) and additional
  2631 comments (tags) are now strictly separate.  Name hints -- which are
  2632 maintained as tags -- may be attached any time without affecting the
  2633 derivation.
  2634 
  2635 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2636 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2637 achieve the old behaviour.
  2638 
  2639 * Pure: the "Goal" constant is now called "prop", supporting a
  2640 slightly more general idea of ``protecting'' meta-level rule
  2641 statements.
  2642 
  2643 * Pure: Logic.(un)varify only works in a global context, which is now
  2644 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2645 Logic.legacy_(un)varify as temporary workaround.
  2646 
  2647 * Pure: structure Name provides scalable operations for generating
  2648 internal variable names, notably Name.variants etc.  This replaces
  2649 some popular functions from term.ML:
  2650 
  2651   Term.variant		->  Name.variant
  2652   Term.variantlist	->  Name.variant_list
  2653   Term.invent_names	->  Name.invent_list
  2654 
  2655 Note that low-level renaming rarely occurs in new code -- operations
  2656 from structure Variable are used instead (see below).
  2657 
  2658 * Pure: structure Variable provides fundamental operations for proper
  2659 treatment of fixed/schematic variables in a context.  For example,
  2660 Variable.import introduces fixes for schematics of given facts and
  2661 Variable.export reverses the effect (up to renaming) -- this replaces
  2662 various freeze_thaw operations.
  2663 
  2664 * Pure: structure Goal provides simple interfaces for
  2665 init/conclude/finish and tactical prove operations (replacing former
  2666 Tactic.prove).  Goal.prove is the canonical way to prove results
  2667 within a given context; Goal.prove_global is a degraded version for
  2668 theory level goals, including a global Drule.standard.  Note that
  2669 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2670 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2671 in a locale context).
  2672 
  2673 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2674 and type checking (Syntax.check_term etc.), with common combinations
  2675 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2676 which are considered legacy and await removal.
  2677 
  2678 * Pure/Syntax: generic interfaces for type unchecking
  2679 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2680 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2681 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2682 available for convenience, but refer to the very same operations using
  2683 a mere theory instead of a full context.
  2684 
  2685 * Isar: simplified treatment of user-level errors, using exception
  2686 ERROR of string uniformly.  Function error now merely raises ERROR,
  2687 without any side effect on output channels.  The Isar toplevel takes
  2688 care of proper display of ERROR exceptions.  ML code may use plain
  2689 handle/can/try; cat_error may be used to concatenate errors like this:
  2690 
  2691   ... handle ERROR msg => cat_error msg "..."
  2692 
  2693 Toplevel ML code (run directly or through the Isar toplevel) may be
  2694 embedded into the Isar toplevel with exception display/debug like
  2695 this:
  2696 
  2697   Isar.toplevel (fn () => ...)
  2698 
  2699 INCOMPATIBILITY, removed special transform_error facilities, removed
  2700 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2701 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2702 -- use plain ERROR instead.
  2703 
  2704 * Isar: theory setup now has type (theory -> theory), instead of a
  2705 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2706 
  2707 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2708 ProofContext.debug/verbose flags.
  2709 
  2710 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2711 theory before entering a proof state.  Transactions now always see a
  2712 quasi-functional intermediate checkpoint, both in interactive and
  2713 batch mode.
  2714 
  2715 * Isar: simplified interfaces for outer syntax.  Renamed
  2716 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2717 OuterSyntax.add_parsers -- this functionality is now included in
  2718 OuterSyntax.command etc.  INCOMPATIBILITY.
  2719 
  2720 * Simplifier: the simpset of a running simplification process now
  2721 contains a proof context (cf. Simplifier.the_context), which is the
  2722 very context that the initial simpset has been retrieved from (by
  2723 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2724 (solver, looper etc.) may depend on arbitrary proof data.
  2725 
  2726 * Simplifier.inherit_context inherits the proof context (plus the
  2727 local bounds) of the current simplification process; any simproc
  2728 etc. that calls the Simplifier recursively should do this!  Removed
  2729 former Simplifier.inherit_bounds, which is already included here --
  2730 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2731 specify an explicit context using Simplifier.context/theory_context.
  2732 
  2733 * Simplifier/Classical Reasoner: more abstract interfaces
  2734 change_simpset/claset for modifying the simpset/claset reference of a
  2735 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2736 INCOMPATIBILITY.
  2737 
  2738 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2739 "Trueprop" etc.
  2740 
  2741 
  2742 *** System ***
  2743 
  2744 * settings: the default heap location within ISABELLE_HOME_USER now
  2745 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2746 Isabelle installations.
  2747 
  2748 * isabelle-process: option -S (secure mode) disables some critical
  2749 operations, notably runtime compilation and evaluation of ML source
  2750 code.
  2751 
  2752 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2753 
  2754 * Support for parallel execution, using native multicore support of
  2755 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2756 independent theories, according to the given theory header
  2757 specifications. The maximum number of worker threads is specified via
  2758 usedir option -M or the "max-threads" setting in Proof General. A
  2759 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2760 to 6 on a 8-core machine.  User-code needs to observe certain
  2761 guidelines for thread-safe programming, see appendix A in the Isar
  2762 Implementation manual.
  2763 
  2764 
  2765 
  2766 New in Isabelle2005 (October 2005)
  2767 ----------------------------------
  2768 
  2769 *** General ***
  2770 
  2771 * Theory headers: the new header syntax for Isar theories is
  2772 
  2773   theory <name>
  2774   imports <theory1> ... <theoryN>
  2775   uses <file1> ... <fileM>
  2776   begin
  2777 
  2778 where the 'uses' part is optional.  The previous syntax
  2779 
  2780   theory <name> = <theory1> + ... + <theoryN>:
  2781 
  2782 will disappear in the next release.  Use isatool fixheaders to convert
  2783 existing theory files.  Note that there is no change in ancient
  2784 non-Isar theories now, but these will disappear soon.
  2785 
  2786 * Theory loader: parent theories can now also be referred to via
  2787 relative and absolute paths.
  2788 
  2789 * Command 'find_theorems' searches for a list of criteria instead of a
  2790 list of constants. Known criteria are: intro, elim, dest, name:string,
  2791 simp:term, and any term. Criteria can be preceded by '-' to select
  2792 theorems that do not match. Intro, elim, dest select theorems that
  2793 match the current goal, name:s selects theorems whose fully qualified
  2794 name contain s, and simp:term selects all simplification rules whose
  2795 lhs match term.  Any other term is interpreted as pattern and selects
  2796 all theorems matching the pattern. Available in ProofGeneral under
  2797 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2798 
  2799   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2800 
  2801 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2802 matching the current goal as introduction rule and not having "HOL."
  2803 in their name (i.e. not being defined in theory HOL).
  2804 
  2805 * Command 'thms_containing' has been discontinued in favour of
  2806 'find_theorems'; INCOMPATIBILITY.
  2807 
  2808 * Communication with Proof General is now 8bit clean, which means that
  2809 Unicode text in UTF-8 encoding may be used within theory texts (both
  2810 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2811 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2812 
  2813   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2814   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2815 
  2816 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2817 Classical Reasoner.  Typical big applications run around 2 times
  2818 faster.
  2819 
  2820 
  2821 *** Document preparation ***
  2822 
  2823 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2824 of raw sources.  Only those symbols that do not require additional
  2825 LaTeX packages (depending on comments in isabellesym.sty) are
  2826 displayed properly, everything else is left verbatim.  isatool display
  2827 and isatool print are used as front ends (these are subject to the
  2828 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2829 
  2830 * Command tags control specific markup of certain regions of text,
  2831 notably folding and hiding.  Predefined tags include "theory" (for
  2832 theory begin and end), "proof" for proof commands, and "ML" for
  2833 commands involving ML code; the additional tags "visible" and
  2834 "invisible" are unused by default.  Users may give explicit tag
  2835 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2836 interpretation of tags is determined by the LaTeX job during document
  2837 preparation: see option -V of isatool usedir, or options -n and -t of
  2838 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2839 \isadroptag.
  2840 
  2841 Several document versions may be produced at the same time via isatool
  2842 usedir (the generated index.html will link all of them).  Typical
  2843 specifications include ''-V document=theory,proof,ML'' to present
  2844 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2845 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2846 these parts without any formal replacement text.  The Isabelle site
  2847 default settings produce ''document'' and ''outline'' versions as
  2848 specified above.
  2849 
  2850 * Several new antiquotations:
  2851 
  2852   @{term_type term} prints a term with its type annotated;
  2853 
  2854   @{typeof term} prints the type of a term;
  2855 
  2856   @{const const} is the same as @{term const}, but checks that the
  2857   argument is a known logical constant;
  2858 
  2859   @{term_style style term} and @{thm_style style thm} print a term or
  2860   theorem applying a "style" to it
  2861 
  2862   @{ML text}
  2863 
  2864 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2865 definitions, equations, inequations etc., 'concl' printing only the
  2866 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2867 to print the specified premise.  TermStyle.add_style provides an ML
  2868 interface for introducing further styles.  See also the "LaTeX Sugar"
  2869 document practical applications.  The ML antiquotation prints
  2870 type-checked ML expressions verbatim.
  2871 
  2872 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2873 and 'text' support optional locale specification '(in loc)', which
  2874 specifies the default context for interpreting antiquotations.  For
  2875 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2876 
  2877 * Option 'locale=NAME' of antiquotations specifies an alternative
  2878 context interpreting the subsequent argument.  For example: @{thm
  2879 [locale=lattice] inf_assoc}.
  2880 
  2881 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2882 a proof context.
  2883 
  2884 * Proper output of antiquotations for theory commands involving a
  2885 proof context (such as 'locale' or 'theorem (in loc) ...').
  2886 
  2887 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2888 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2889 
  2890 * isatool usedir: new option -C (default true) controls whether option
  2891 -D should include a copy of the original document directory; -C false
  2892 prevents unwanted effects such as copying of administrative CVS data.
  2893 
  2894 
  2895 *** Pure ***
  2896 
  2897 * Considerably improved version of 'constdefs' command.  Now performs
  2898 automatic type-inference of declared constants; additional support for
  2899 local structure declarations (cf. locales and HOL records), see also
  2900 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  2901 sequential dependencies of definitions within a single 'constdefs'
  2902 section; moreover, the declared name needs to be an identifier.  If
  2903 all fails, consider to fall back on 'consts' and 'defs' separately.
  2904 
  2905 * Improved indexed syntax and implicit structures.  First of all,
  2906 indexed syntax provides a notational device for subscripted
  2907 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  2908 expressions.  Secondly, in a local context with structure
  2909 declarations, number indexes \<^sub>n or the empty index (default
  2910 number 1) refer to a certain fixed variable implicitly; option
  2911 show_structs controls printing of implicit structures.  Typical
  2912 applications of these concepts involve record types and locales.
  2913 
  2914 * New command 'no_syntax' removes grammar declarations (and
  2915 translations) resulting from the given syntax specification, which is
  2916 interpreted in the same manner as for the 'syntax' command.
  2917 
  2918 * 'Advanced' translation functions (parse_translation etc.) may depend
  2919 on the signature of the theory context being presently used for
  2920 parsing/printing, see also isar-ref manual.
  2921 
  2922 * Improved 'oracle' command provides a type-safe interface to turn an
  2923 ML expression of type theory -> T -> term into a primitive rule of
  2924 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  2925 is already included here); see also FOL/ex/IffExample.thy;
  2926 INCOMPATIBILITY.
  2927 
  2928 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  2929 before); "cI" is no longer bound, use "c.intro" instead.
  2930 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  2931 axclasses vs. locales.
  2932 
  2933 * Improved internal renaming of symbolic identifiers -- attach primes
  2934 instead of base 26 numbers.
  2935 
  2936 * New flag show_question_marks controls printing of leading question
  2937 marks in schematic variable names.
  2938 
  2939 * In schematic variable names, *any* symbol following \<^isub> or
  2940 \<^isup> is now treated as part of the base name.  For example, the
  2941 following works without printing of awkward ".0" indexes:
  2942 
  2943   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  2944     by simp
  2945 
  2946 * Inner syntax includes (*(*nested*) comments*).
  2947 
  2948 * Pretty printer now supports unbreakable blocks, specified in mixfix
  2949 annotations as "(00...)".
  2950 
  2951 * Clear separation of logical types and nonterminals, where the latter
  2952 may only occur in 'syntax' specifications or type abbreviations.
  2953 Before that distinction was only partially implemented via type class
  2954 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  2955 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  2956 exotic syntax specifications may require further adaption
  2957 (e.g. Cube/Cube.thy).
  2958 
  2959 * Removed obsolete type class "logic", use the top sort {} instead.
  2960 Note that non-logical types should be declared as 'nonterminals'
  2961 rather than 'types'.  INCOMPATIBILITY for new object-logic
  2962 specifications.
  2963 
  2964 * Attributes 'induct' and 'cases': type or set names may now be
  2965 locally fixed variables as well.
  2966 
  2967 * Simplifier: can now control the depth to which conditional rewriting
  2968 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  2969 Limit.
  2970 
  2971 * Simplifier: simplification procedures may now take the current
  2972 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  2973 interface), which is very useful for calling the Simplifier
  2974 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  2975 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  2976 low-level mk_simproc no longer applies Logic.varify internally, to
  2977 allow for use in a context of fixed variables.
  2978 
  2979 * thin_tac now works even if the assumption being deleted contains !!
  2980 or ==>.  More generally, erule now works even if the major premise of
  2981 the elimination rule contains !! or ==>.
  2982 
  2983 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  2984 
  2985 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  2986 from Pure, which contains all common declarations already.  Both
  2987 theories are defined via plain Isabelle/Isar .thy files.
  2988 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  2989 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  2990 use isatool fixcpure to adapt your theory and ML sources.
  2991 
  2992 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  2993 selections of theorems in named facts via index ranges.
  2994 
  2995 * 'print_theorems': in theory mode, really print the difference
  2996 wrt. the last state (works for interactive theory development only),
  2997 in proof mode print all local facts (cf. 'print_facts');
  2998 
  2999 * 'hide': option '(open)' hides only base names.
  3000 
  3001 * More efficient treatment of intermediate checkpoints in interactive
  3002 theory development.
  3003 
  3004 * Code generator is now invoked via code_module (incremental code
  3005 generation) and code_library (modular code generation, ML structures
  3006 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3007 must be quoted when used as identifiers.
  3008 
  3009 * New 'value' command for reading, evaluating and printing terms using
  3010 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3011 quoted when used as identifier.
  3012 
  3013 
  3014 *** Locales ***
  3015 
  3016 * New commands for the interpretation of locale expressions in
  3017 theories (1), locales (2) and proof contexts (3).  These generate
  3018 proof obligations from the expression specification.  After the
  3019 obligations have been discharged, theorems of the expression are added
  3020 to the theory, target locale or proof context.  The synopsis of the
  3021 commands is a follows:
  3022 
  3023   (1) interpretation expr inst
  3024   (2) interpretation target < expr
  3025   (3) interpret expr inst
  3026 
  3027 Interpretation in theories and proof contexts require a parameter
  3028 instantiation of terms from the current context.  This is applied to
  3029 specifications and theorems of the interpreted expression.
  3030 Interpretation in locales only permits parameter renaming through the
  3031 locale expression.  Interpretation is smart in that interpretations
  3032 that are active already do not occur in proof obligations, neither are
  3033 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3034 inspect active interpretations of a particular locale.  For details,
  3035 see the Isar Reference manual.  Examples can be found in
  3036 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3037 
  3038 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3039 'interpret' instead.
  3040 
  3041 * New context element 'constrains' for adding type constraints to
  3042 parameters.
  3043 
  3044 * Context expressions: renaming of parameters with syntax
  3045 redeclaration.
  3046 
  3047 * Locale declaration: 'includes' disallowed.
  3048 
  3049 * Proper static binding of attribute syntax -- i.e. types / terms /
  3050 facts mentioned as arguments are always those of the locale definition
  3051 context, independently of the context of later invocations.  Moreover,
  3052 locale operations (renaming and type / term instantiation) are applied
  3053 to attribute arguments as expected.
  3054 
  3055 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3056 actual attributes; rare situations may require Attrib.attribute to
  3057 embed those attributes into Attrib.src that lack concrete syntax.
  3058 Attribute implementations need to cooperate properly with the static
  3059 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3060 Attrib.XXX_thm etc. already do the right thing without further
  3061 intervention.  Only unusual applications -- such as "where" or "of"
  3062 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3063 on the context and the facts involved -- may have to assign parsed
  3064 values to argument tokens explicitly.
  3065 
  3066 * Changed parameter management in theorem generation for long goal
  3067 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3068 theorem statement in rare situations.
  3069 
  3070 * Locale inspection command 'print_locale' omits notes elements.  Use
  3071 'print_locale!' to have them included in the output.
  3072 
  3073 
  3074 *** Provers ***
  3075 
  3076 * Provers/hypsubst.ML: improved version of the subst method, for
  3077 single-step rewriting: it now works in bound variable contexts. New is
  3078 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3079 rewrite a different subterm than the original subst method, which is
  3080 still available as 'simplesubst'.
  3081 
  3082 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3083 and quasi orders.
  3084 
  3085 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3086 reflexive-transitive closure of relations.
  3087 
  3088 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3089 limit (previously hard-coded with a value of 20) user-definable.
  3090 
  3091 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3092 is peformed already.  Object-logics merely need to finish their
  3093 initial simpset configuration as before.  INCOMPATIBILITY.
  3094 
  3095 
  3096 *** HOL ***
  3097 
  3098 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3099 
  3100   syntax (epsilon)
  3101     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3102 
  3103 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3104 and x-symbol; use option '-m epsilon' to get it actually printed.
  3105 Moreover, the mathematically important symbolic identifier \<epsilon>
  3106 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3107 
  3108 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3109 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3110 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3111 support corresponding Isar calculations.
  3112 
  3113 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3114 instead of ":".
  3115 
  3116 * theory SetInterval: changed the syntax for open intervals:
  3117 
  3118   Old       New
  3119   {..n(}    {..<n}
  3120   {)n..}    {n<..}
  3121   {m..n(}   {m..<n}
  3122   {)m..n}   {m<..n}
  3123   {)m..n(}  {m<..<n}
  3124 
  3125 The old syntax is still supported but will disappear in the next
  3126 release.  For conversion use the following Emacs search and replace
  3127 patterns (these are not perfect but work quite well):
  3128 
  3129   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3130   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3131 
  3132 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3133 equalities in commutative rings; method 'algebra' provides a generic
  3134 interface.
  3135 
  3136 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3137 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3138 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3139 be a tuple pattern.
  3140 
  3141 Some new syntax forms are available:
  3142 
  3143   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3144   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3145   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3146   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3147 
  3148 The latter form "\<Sum>x < k. e" used to be based on a separate
  3149 function "Summation", which has been discontinued.
  3150 
  3151 * theory Finite_Set: in structured induction proofs, the insert case
  3152 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3153 (insert F x)'.
  3154 
  3155 * The 'refute' command has been extended to support a much larger
  3156 fragment of HOL, including axiomatic type classes, constdefs and
  3157 typedefs, inductive datatypes and recursion.
  3158 
  3159 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3160 Requires zChaff with proof generation to be installed.  See
  3161 HOL/ex/SAT_Examples.thy for examples.
  3162 
  3163 * Datatype induction via method 'induct' now preserves the name of the
  3164 induction variable. For example, when proving P(xs::'a list) by
  3165 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3166 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3167 in unstructured proof scripts.
  3168 
  3169 * Reworked implementation of records.  Improved scalability for
  3170 records with many fields, avoiding performance problems for type
  3171 inference. Records are no longer composed of nested field types, but
  3172 of nested extension types. Therefore the record type only grows linear
  3173 in the number of extensions and not in the number of fields.  The
  3174 top-level (users) view on records is preserved.  Potential
  3175 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3176 old record representation. The type generated for a record is called
  3177 <record_name>_ext_type.
  3178 
  3179 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3180 proofs triggered by a record definition or a simproc (if
  3181 quick_and_dirty is enabled).  Definitions of large records can take
  3182 quite long.
  3183 
  3184 New simproc record_upd_simproc for simplification of multiple record
  3185 updates enabled by default.  Moreover, trivial updates are also
  3186 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3187 occasionally, since simplification is more powerful by default.
  3188 
  3189 * typedef: proper support for polymorphic sets, which contain extra
  3190 type-variables in the term.
  3191 
  3192 * Simplifier: automatically reasons about transitivity chains
  3193 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3194 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3195 old proofs break occasionally as simplification may now solve more
  3196 goals than previously.
  3197 
  3198 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3199 present.  Works for all partial orders (class "order"), in particular
  3200 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3201 just like y <= x.
  3202 
  3203 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3204 bound variable or a constant then the let is unfolded.  Otherwise
  3205 first a is simplified to b, and then f b is simplified to g. If
  3206 possible we abstract b from g arriving at "let x = b in h x",
  3207 otherwise we unfold the let and arrive at g.  The simproc can be
  3208 enabled/disabled by the reference use_let_simproc.  Potential
  3209 INCOMPATIBILITY since simplification is more powerful by default.
  3210 
  3211 * Classical reasoning: the meson method now accepts theorems as arguments.
  3212 
  3213 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3214 jobs to provide advice on the provability of subgoals.
  3215 
  3216 * Theory OrderedGroup and Ring_and_Field: various additions and
  3217 improvements to faciliate calculations involving equalities and
  3218 inequalities.
  3219 
  3220 The following theorems have been eliminated or modified
  3221 (INCOMPATIBILITY):
  3222 
  3223   abs_eq             now named abs_of_nonneg
  3224   abs_of_ge_0        now named abs_of_nonneg
  3225   abs_minus_eq       now named abs_of_nonpos
  3226   imp_abs_id         now named abs_of_nonneg
  3227   imp_abs_neg_id     now named abs_of_nonpos
  3228   mult_pos           now named mult_pos_pos
  3229   mult_pos_le        now named mult_nonneg_nonneg
  3230   mult_pos_neg_le    now named mult_nonneg_nonpos
  3231   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3232   mult_neg           now named mult_neg_neg
  3233   mult_neg_le        now named mult_nonpos_nonpos
  3234 
  3235 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3236      
  3237      zero_le_square
  3238      not_square_less_zero 
  3239 
  3240   The following lemmas have been deleted from Real/RealPow:
  3241   
  3242      realpow_zero_zero
  3243      realpow_two
  3244      realpow_less
  3245      zero_le_power
  3246      realpow_two_le
  3247      abs_realpow_two
  3248      realpow_two_abs     
  3249 
  3250 * Theory Parity: added rules for simplifying exponents.
  3251 
  3252 * Theory List:
  3253 
  3254 The following theorems have been eliminated or modified
  3255 (INCOMPATIBILITY):
  3256 
  3257   list_all_Nil       now named list_all.simps(1)
  3258   list_all_Cons      now named list_all.simps(2)
  3259   list_all_conv      now named list_all_iff
  3260   set_mem_eq         now named mem_iff
  3261 
  3262 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3263 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3264 
  3265 
  3266 *** HOL-Complex ***
  3267 
  3268 * Theory RealDef: better support for embedding natural numbers and
  3269 integers in the reals.
  3270 
  3271 The following theorems have been eliminated or modified
  3272 (INCOMPATIBILITY):
  3273 
  3274   exp_ge_add_one_self  now requires no hypotheses
  3275   real_of_int_add      reversed direction of equality (use [symmetric])
  3276   real_of_int_minus    reversed direction of equality (use [symmetric])
  3277   real_of_int_diff     reversed direction of equality (use [symmetric])
  3278   real_of_int_mult     reversed direction of equality (use [symmetric])
  3279 
  3280 * Theory RComplete: expanded support for floor and ceiling functions.
  3281 
  3282 * Theory Ln is new, with properties of the natural logarithm
  3283 
  3284 * Hyperreal: There is a new type constructor "star" for making
  3285 nonstandard types.  The old type names are now type synonyms:
  3286 
  3287   hypreal = real star
  3288   hypnat = nat star
  3289   hcomplex = complex star
  3290 
  3291 * Hyperreal: Many groups of similarly-defined constants have been
  3292 replaced by polymorphic versions (INCOMPATIBILITY):
  3293 
  3294   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3295 
  3296   starset      <-- starsetNat, starsetC
  3297   *s*          <-- *sNat*, *sc*
  3298   starset_n    <-- starsetNat_n, starsetC_n
  3299   *sn*         <-- *sNatn*, *scn*
  3300   InternalSets <-- InternalNatSets, InternalCSets
  3301 
  3302   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3303   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3304   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3305   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3306   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3307 
  3308 * Hyperreal: Many type-specific theorems have been removed in favor of
  3309 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3310 
  3311   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3312   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3313   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3314   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3315   right_minus <-- hypreal_add_minus
  3316   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3317   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3318   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3319   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3320   mult_1_right <-- hcomplex_mult_one_right
  3321   mult_zero_left <-- hcomplex_mult_zero_left
  3322   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3323   right_distrib <-- hypnat_add_mult_distrib2
  3324   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3325   right_inverse <-- hypreal_mult_inverse
  3326   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3327   order_refl <-- {hypreal,hypnat}_le_refl
  3328   order_trans <-- {hypreal,hypnat}_le_trans
  3329   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3330   order_less_le <-- {hypreal,hypnat}_less_le
  3331   linorder_linear <-- {hypreal,hypnat}_le_linear
  3332   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3333   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3334   add_nonneg_nonneg <-- hypreal_le_add_order
  3335 
  3336 * Hyperreal: Separate theorems having to do with type-specific
  3337 versions of constants have been merged into theorems that apply to the
  3338 new polymorphic constants (INCOMPATIBILITY):
  3339 
  3340   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3341   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3342   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3343   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3344   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3345   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3346   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3347   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3348   STAR_diff <-- {STAR,STARC}_diff
  3349   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3350     STARC_hcomplex_of_complex}_image_subset
  3351   starset_n_Un <-- starset{Nat,C}_n_Un
  3352   starset_n_Int <-- starset{Nat,C}_n_Int
  3353   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3354   starset_n_diff <-- starset{Nat,C}_n_diff
  3355   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3356   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3357   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3358   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3359   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3360   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3361   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3362   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3363   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3364   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3365   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3366   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3367   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3368   starfun_diff <-- starfun{C,RC,CR}_diff
  3369   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3370   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3371   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3372   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3373   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3374   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3375   starfun_Id <-- starfunC_Id
  3376   starfun_approx <-- starfun{Nat,CR}_approx
  3377   starfun_capprox <-- starfun{C,RC}_capprox
  3378   starfun_abs <-- starfunNat_rabs
  3379   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3380   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3381   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3382   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3383   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3384   starfun_add_approx <-- starfunCR_add_approx
  3385   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3386   starfun_divide <-- starfun{C,CR,RC}_divide
  3387   starfun_n <-- starfun{Nat,C}_n
  3388   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3389   starfun_n_add <-- starfun{Nat,C}_n_add
  3390   starfun_n_add_minus <-- starfunNat_n_add_minus
  3391   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3392   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3393   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3394 
  3395   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3396   star_n_minus <-- {hypreal,hcomplex}_minus
  3397   star_n_diff <-- {hypreal,hcomplex}_diff
  3398   star_n_mult <-- {hypreal,hcomplex}_mult
  3399   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3400   star_n_le <-- {hypreal,hypnat}_le
  3401   star_n_less <-- {hypreal,hypnat}_less
  3402   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3403   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3404   star_n_abs <-- hypreal_hrabs
  3405   star_n_divide <-- hcomplex_divide
  3406 
  3407   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3408   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3409   star_of_diff <-- hypreal_of_real_diff
  3410   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3411   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3412   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3413   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3414   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3415   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3416   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3417   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3418   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3419   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3420   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3421   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3422   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3423   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3424   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3425   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3426   star_of_power <-- hypreal_of_real_power
  3427   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3428 
  3429 * Hyperreal: new method "transfer" that implements the transfer
  3430 principle of nonstandard analysis. With a subgoal that mentions
  3431 nonstandard types like "'a star", the command "apply transfer"
  3432 replaces it with an equivalent one that mentions only standard types.
  3433 To be successful, all free variables must have standard types; non-
  3434 standard variables must have explicit universal quantifiers.
  3435 
  3436 * Hyperreal: A theory of Taylor series.
  3437 
  3438 
  3439 *** HOLCF ***
  3440 
  3441 * Discontinued special version of 'constdefs' (which used to support
  3442 continuous functions) in favor of the general Pure one with full
  3443 type-inference.
  3444 
  3445 * New simplification procedure for solving continuity conditions; it
  3446 is much faster on terms with many nested lambda abstractions (cubic
  3447 instead of exponential time).
  3448 
  3449 * New syntax for domain package: selector names are now optional.
  3450 Parentheses should be omitted unless argument is lazy, for example:
  3451 
  3452   domain 'a stream = cons "'a" (lazy "'a stream")
  3453 
  3454 * New command 'fixrec' for defining recursive functions with pattern
  3455 matching; defining multiple functions with mutual recursion is also
  3456 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3457 sinr, or any data constructor defined by the domain package. The given
  3458 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3459 syntax and examples.
  3460 
  3461 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3462 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3463 but the proof obligation additionally includes an admissibility
  3464 requirement. The packages generate instances of class cpo or pcpo,
  3465 with continuity and strictness theorems for Rep and Abs.
  3466 
  3467 * HOLCF: Many theorems have been renamed according to a more standard naming
  3468 scheme (INCOMPATIBILITY):
  3469 
  3470   foo_inject:  "foo$x = foo$y ==> x = y"
  3471   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3472   foo_less:    "(foo$x << foo$y) = (x << y)"
  3473   foo_strict:  "foo$UU = UU"
  3474   foo_defined: "... ==> foo$x ~= UU"
  3475   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3476 
  3477 
  3478 *** ZF ***
  3479 
  3480 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3481 including the First Isomorphism Theorem (on quotienting by the kernel
  3482 of a homomorphism).
  3483 
  3484 * ZF/Simplifier: install second copy of type solver that actually
  3485 makes use of TC rules declared to Isar proof contexts (or locales);
  3486 the old version is still required for ML proof scripts.
  3487 
  3488 
  3489 *** Cube ***
  3490 
  3491 * Converted to Isar theory format; use locales instead of axiomatic
  3492 theories.
  3493 
  3494 
  3495 *** ML ***
  3496 
  3497 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3498 for ||>, ||>>, |>>,
  3499 
  3500 * Pure/library.ML no longer defines its own option datatype, but uses
  3501 that of the SML basis, which has constructors NONE and SOME instead of
  3502 None and Some, as well as exception Option.Option instead of OPTION.
  3503 The functions the, if_none, is_some, is_none have been adapted
  3504 accordingly, while Option.map replaces apsome.
  3505 
  3506 * Pure/library.ML: the exception LIST has been given up in favour of
  3507 the standard exceptions Empty and Subscript, as well as
  3508 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3509 superceded by the standard hd and tl functions etc.
  3510 
  3511 A number of basic list functions are no longer exported to the ML
  3512 toplevel, as they are variants of predefined functions.  The following
  3513 suggests how one can translate existing code:
  3514 
  3515     rev_append xs ys = List.revAppend (xs, ys)
  3516     nth_elem (i, xs) = List.nth (xs, i)
  3517     last_elem xs = List.last xs
  3518     flat xss = List.concat xss
  3519     seq fs = List.app fs
  3520     partition P xs = List.partition P xs
  3521     mapfilter f xs = List.mapPartial f xs
  3522 
  3523 * Pure/library.ML: several combinators for linear functional
  3524 transformations, notably reverse application and composition:
  3525 
  3526   x |> f                f #> g
  3527   (x, y) |-> f          f #-> g
  3528 
  3529 * Pure/library.ML: introduced/changed precedence of infix operators:
  3530 
  3531   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3532   infix 2 ?;
  3533   infix 3 o oo ooo oooo;
  3534   infix 4 ~~ upto downto;
  3535 
  3536 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3537 infix operators.
  3538 
  3539 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3540 fold_map support linear functional transformations and nesting.  For
  3541 example:
  3542 
  3543   fold f [x1, ..., xN] y =
  3544     y |> f x1 |> ... |> f xN
  3545 
  3546   (fold o fold) f [xs1, ..., xsN] y =
  3547     y |> fold f xs1 |> ... |> fold f xsN
  3548 
  3549   fold f [x1, ..., xN] =
  3550     f x1 #> ... #> f xN
  3551 
  3552   (fold o fold) f [xs1, ..., xsN] =
  3553     fold f xs1 #> ... #> fold f xsN
  3554 
  3555 * Pure/library.ML: the following selectors on type 'a option are
  3556 available:
  3557 
  3558   the:               'a option -> 'a  (*partial*)
  3559   these:             'a option -> 'a  where 'a = 'b list
  3560   the_default: 'a -> 'a option -> 'a
  3561   the_list:          'a option -> 'a list
  3562 
  3563 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3564 basic operations for association lists, following natural argument
  3565 order; moreover the explicit equality predicate passed here avoids
  3566 potentially expensive polymorphic runtime equality checks.
  3567 The old functions may be expressed as follows:
  3568 
  3569   assoc = uncurry (AList.lookup (op =))
  3570   assocs = these oo AList.lookup (op =)
  3571   overwrite = uncurry (AList.update (op =)) o swap
  3572 
  3573 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3574 
  3575   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3576   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3577 
  3578 replacing make_keylist and keyfilter (occassionally used)
  3579 Naive rewrites:
  3580 
  3581   make_keylist = AList.make
  3582   keyfilter = AList.find (op =)
  3583 
  3584 * eq_fst and eq_snd now take explicit equality parameter, thus
  3585   avoiding eqtypes. Naive rewrites:
  3586 
  3587     eq_fst = eq_fst (op =)
  3588     eq_snd = eq_snd (op =)
  3589 
  3590 * Removed deprecated apl and apr (rarely used).
  3591   Naive rewrites:
  3592 
  3593     apl (n, op) =>>= curry op n
  3594     apr (op, m) =>>= fn n => op (n, m)
  3595 
  3596 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3597 provides a reasonably efficient light-weight implementation of sets as
  3598 lists.
  3599 
  3600 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3601 few new operations; existing lookup and update are now curried to
  3602 follow natural argument order (for use with fold etc.);
  3603 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3604 
  3605 * Pure/General: output via the Isabelle channels of
  3606 writeln/warning/error etc. is now passed through Output.output, with a
  3607 hook for arbitrary transformations depending on the print_mode
  3608 (cf. Output.add_mode -- the first active mode that provides a output
  3609 function wins).  Already formatted output may be embedded into further
  3610 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3611 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3612 accommodate easy composition of diagnostic messages etc.  Programmers
  3613 rarely need to care about Output.output or Output.raw at all, with
  3614 some notable exceptions: Output.output is required when bypassing the
  3615 standard channels (writeln etc.), or in token translations to produce
  3616 properly formatted results; Output.raw is required when capturing
  3617 already output material that will eventually be presented to the user
  3618 a second time.  For the default print mode, both Output.output and
  3619 Output.raw have no effect.
  3620 
  3621 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3622 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3623 cumulative results are displayed at the end of a batch session.
  3624 
  3625 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3626 replaced by File.platform_path and File.shell_path (with appropriate
  3627 hooks).  This provides a clean interface for unusual systems where the
  3628 internal and external process view of file names are different.
  3629 
  3630 * Pure: more efficient orders for basic syntactic entities: added
  3631 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3632 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3633 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3634 orders now -- potential INCOMPATIBILITY for code that depends on a
  3635 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3636 Library.sort_strings on result).
  3637 
  3638 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3639 fold_types traverse types/terms from left to right, observing natural
  3640 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3641 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3642 
  3643 * Pure: name spaces have been refined, with significant changes of the
  3644 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3645 to extern(_table).  The plain name entry path is superceded by a
  3646 general 'naming' context, which also includes the 'policy' to produce
  3647 a fully qualified name and external accesses of a fully qualified
  3648 name; NameSpace.extend is superceded by context dependent
  3649 Sign.declare_name.  Several theory and proof context operations modify
  3650 the naming context.  Especially note Theory.restore_naming and
  3651 ProofContext.restore_naming to get back to a sane state; note that
  3652 Theory.add_path is no longer sufficient to recover from
  3653 Theory.absolute_path in particular.
  3654 
  3655 * Pure: new flags short_names (default false) and unique_names
  3656 (default true) for controlling output of qualified names.  If
  3657 short_names is set, names are printed unqualified.  If unique_names is
  3658 reset, the name prefix is reduced to the minimum required to achieve
  3659 the original result when interning again, even if there is an overlap
  3660 with earlier declarations.
  3661 
  3662 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3663 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3664 (useful for printing error messages).  INCOMPATIBILITY.
  3665 
  3666 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3667 Theory.theory are now identified, referring to the universal
  3668 Context.theory (see Pure/context.ML).  Actual signature and theory
  3669 content is managed as theory data.  The old code and interfaces were
  3670 spread over many files and structures; the new arrangement introduces
  3671 considerable INCOMPATIBILITY to gain more clarity:
  3672 
  3673   Context -- theory management operations (name, identity, inclusion,
  3674     parents, ancestors, merge, etc.), plus generic theory data;
  3675 
  3676   Sign -- logical signature and syntax operations (declaring consts,
  3677     types, etc.), plus certify/read for common entities;
  3678 
  3679   Theory -- logical theory operations (stating axioms, definitions,
  3680     oracles), plus a copy of logical signature operations (consts,
  3681     types, etc.); also a few basic management operations (Theory.copy,
  3682     Theory.merge, etc.)
  3683 
  3684 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3685 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3686 for convenience -- they merely return the theory.
  3687 
  3688 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3689 
  3690 * Pure: the Isar proof context type is already defined early in Pure
  3691 as Context.proof (note that ProofContext.context and Proof.context are
  3692 aliases, where the latter is the preferred name).  This enables other
  3693 Isabelle components to refer to that type even before Isar is present.
  3694 
  3695 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3696 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3697 any of these kinds.  For example, Sign.intern typeK is now
  3698 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3699 Theory.hide_types.  Also note that former
  3700 Theory.hide_classes/types/consts are now
  3701 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3702 internalize their arguments!  INCOMPATIBILITY.
  3703 
  3704 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3705 datatype thmref (with constructors Name and NameSelection) instead of
  3706 plain string -- INCOMPATIBILITY;
  3707 
  3708 * Pure: cases produced by proof methods specify options, where NONE
  3709 means to remove case bindings -- INCOMPATIBILITY in
  3710 (RAW_)METHOD_CASES.
  3711 
  3712 * Pure: the following operations retrieve axioms or theorems from a
  3713 theory node or theory hierarchy, respectively:
  3714 
  3715   Theory.axioms_of: theory -> (string * term) list
  3716   Theory.all_axioms_of: theory -> (string * term) list
  3717   PureThy.thms_of: theory -> (string * thm) list
  3718   PureThy.all_thms_of: theory -> (string * thm) list
  3719 
  3720 * Pure: print_tac now outputs the goal through the trace channel.
  3721 
  3722 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3723 Reference Toplevel.debug (default false) controls detailed printing
  3724 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3725 controls execution profiling -- set to 1 for time and 2 for space
  3726 (both increase the runtime).
  3727 
  3728 * Isar session: The initial use of ROOT.ML is now always timed,
  3729 i.e. the log will show the actual process times, in contrast to the
  3730 elapsed wall-clock time that the outer shell wrapper produces.
  3731 
  3732 * Simplifier: improved handling of bound variables (nameless
  3733 representation, avoid allocating new strings).  Simprocs that invoke
  3734 the Simplifier recursively should use Simplifier.inherit_bounds to
  3735 avoid local name clashes.  Failure to do so produces warnings
  3736 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3737 for further details.
  3738 
  3739 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3740 bindings for all theorems stored within a given theory; this may help
  3741 in porting non-Isar theories to Isar ones, while keeping ML proof
  3742 scripts for the time being.
  3743 
  3744 * ML operator HTML.with_charset specifies the charset begin used for
  3745 generated HTML files.  For example:
  3746 
  3747   HTML.with_charset "utf-8" use_thy "Hebrew";
  3748   HTML.with_charset "utf-8" use_thy "Chinese";
  3749 
  3750 
  3751 *** System ***
  3752 
  3753 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3754 isabelle, isatool etc.).
  3755 
  3756 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3757 isatool doc, isatool mkdir, display_drafts etc.).
  3758 
  3759 * isatool usedir: option -f allows specification of the ML file to be
  3760 used by Isabelle; default is ROOT.ML.
  3761 
  3762 * New isatool version outputs the version identifier of the Isabelle
  3763 distribution being used.
  3764 
  3765 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3766 (containing Boolean satisfiability problems) into Isabelle/HOL
  3767 theories.
  3768 
  3769 
  3770 
  3771 New in Isabelle2004 (April 2004)
  3772 --------------------------------
  3773 
  3774 *** General ***
  3775 
  3776 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3777   Replaces linorder.ML.
  3778 
  3779 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3780   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3781   (\<a>...\<z>), are now considered normal letters, and can therefore
  3782   be used anywhere where an ASCII letter (a...zA...Z) has until
  3783   now. COMPATIBILITY: This obviously changes the parsing of some
  3784   terms, especially where a symbol has been used as a binder, say
  3785   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3786   as an identifier.  Fix it by inserting a space around former
  3787   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3788   existing theory and ML files.
  3789 
  3790 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3791 
  3792 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3793   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3794   a normal (but invisible) letter. For multiple letter subscripts repeat
  3795   \<^isub> like this: x\<^isub>1\<^isub>2.
  3796 
  3797 * Pure: There are now sub-/superscripts that can span more than one
  3798   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3799   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3800   superscript. The new control characters are not identifier parts.
  3801 
  3802 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3803   content of "..." to the latex file instead of \isacntrl... . The "..."
  3804   may consist of any printable characters excluding the end bracket >.
  3805 
  3806 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3807   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3808   declare constants "final", which prevents their being given a definition
  3809   later.  It is useful for constants whose behaviour is fixed axiomatically
  3810   rather than definitionally, such as the meta-logic connectives.
  3811 
  3812 * Pure: 'instance' now handles general arities with general sorts
  3813   (i.e. intersections of classes),
  3814 
  3815 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3816   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3817   It can be changed to alter the colors/layout of generated pages.
  3818 
  3819 
  3820 *** Isar ***
  3821 
  3822 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3823   cut_tac, subgoal_tac and thin_tac:
  3824   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3825     locales are no longer forced to write Isar proof scripts.
  3826     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3827     emulations.
  3828   - INCOMPATIBILITY: names of variables to be instantiated may no
  3829     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3830     This is consistent with the instantiation attribute "where".
  3831 
  3832 * Attributes "where" and "of":
  3833   - Now take type variables of instantiated theorem into account when reading
  3834     the instantiation string.  This fixes a bug that caused instantiated
  3835     theorems to have too special types in some circumstances.
  3836   - "where" permits explicit instantiations of type variables.
  3837 
  3838 * Calculation commands "moreover" and "also" no longer interfere with
  3839   current facts ("this"), admitting arbitrary combinations with "then"
  3840   and derived forms.
  3841 
  3842 * Locales:
  3843   - Goal statements involving the context element "includes" no longer
  3844     generate theorems with internal delta predicates (those ending on
  3845     "_axioms") in the premise.
  3846     Resolve particular premise with <locale>.intro to obtain old form.
  3847   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3848     specification and "includes" elements in goal statement.
  3849   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3850     [intro?] and [elim?] (respectively) by default.
  3851   - Experimental command for instantiation of locales in proof contexts:
  3852         instantiate <label>[<attrs>]: <loc>
  3853     Instantiates locale <loc> and adds all its theorems to the current context
  3854     taking into account their attributes.  Label and attrs are optional
  3855     modifiers, like in theorem declarations.  If present, names of
  3856     instantiated theorems are qualified with <label>, and the attributes
  3857     <attrs> are applied after any attributes these theorems might have already.
  3858       If the locale has assumptions, a chained fact of the form
  3859     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3860     are derived.  The command does not support old-style locales declared
  3861     with "locale (open)".
  3862       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3863 
  3864 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3865   (Isar) contexts.
  3866 
  3867 
  3868 *** HOL ***
  3869 
  3870 * Proof import: new image HOL4 contains the imported library from
  3871   the HOL4 system with about 2500 theorems. It is imported by
  3872   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3873   can be used like any other Isabelle image.  See
  3874   HOL/Import/HOL/README for more information.
  3875 
  3876 * Simplifier:
  3877   - Much improved handling of linear and partial orders.
  3878     Reasoners for linear and partial orders are set up for type classes
  3879     "linorder" and "order" respectively, and are added to the default simpset
  3880     as solvers.  This means that the simplifier can build transitivity chains
  3881     to solve goals from the assumptions.
  3882   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3883     of blast or auto after simplification become unnecessary because the goal
  3884     is solved by simplification already.
  3885 
  3886 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3887     all proved in axiomatic type classes for semirings, rings and fields.
  3888 
  3889 * Numerics:
  3890   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3891     now formalized using the Ring_and_Field theory mentioned above.
  3892   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3893     than before, because now they are set up once in a generic manner.
  3894   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  3895     Look for the general versions in Ring_and_Field (and Power if they concern
  3896     exponentiation).
  3897 
  3898 * Type "rat" of the rational numbers is now available in HOL-Complex.
  3899 
  3900 * Records:
  3901   - Record types are now by default printed with their type abbreviation
  3902     instead of the list of all field types. This can be configured via
  3903     the reference "print_record_type_abbr".
  3904   - Simproc "record_upd_simproc" for simplification of multiple updates added
  3905     (not enabled by default).
  3906   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  3907     EX x. x = sel r to True (not enabled by default).
  3908   - Tactic "record_split_simp_tac" to split and simplify records added.
  3909 
  3910 * 'specification' command added, allowing for definition by
  3911   specification.  There is also an 'ax_specification' command that
  3912   introduces the new constants axiomatically.
  3913 
  3914 * arith(_tac) is now able to generate counterexamples for reals as well.
  3915 
  3916 * HOL-Algebra: new locale "ring" for non-commutative rings.
  3917 
  3918 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  3919   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  3920 
  3921 * HOL-Matrix: a first theory for matrices in HOL with an application of
  3922   matrix theory to linear programming.
  3923 
  3924 * Unions and Intersections:
  3925   The latex output syntax of UN and INT has been changed
  3926   from "\Union x \in A. B" to "\Union_{x \in A} B"
  3927   i.e. the index formulae has become a subscript.
  3928   Similarly for "\Union x. B", and for \Inter instead of \Union.
  3929 
  3930 * Unions and Intersections over Intervals:
  3931   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  3932   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  3933   like in normal math, and corresponding versions for < and for intersection.
  3934 
  3935 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  3936   lexicographic dictonary ordering has been added as "lexord".
  3937 
  3938 * ML: the legacy theory structures Int and List have been removed. They had
  3939   conflicted with ML Basis Library structures having the same names.
  3940 
  3941 * 'refute' command added to search for (finite) countermodels.  Only works
  3942   for a fragment of HOL.  The installation of an external SAT solver is
  3943   highly recommended.  See "HOL/Refute.thy" for details.
  3944 
  3945 * 'quickcheck' command: Allows to find counterexamples by evaluating
  3946   formulae under an assignment of free variables to random values.
  3947   In contrast to 'refute', it can deal with inductive datatypes,
  3948   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  3949   for examples.
  3950 
  3951 
  3952 *** HOLCF ***
  3953 
  3954 * Streams now come with concatenation and are part of the HOLCF image
  3955 
  3956 
  3957 
  3958 New in Isabelle2003 (May 2003)
  3959 ------------------------------
  3960 
  3961 *** General ***
  3962 
  3963 * Provers/simplifier:
  3964 
  3965   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  3966     Assumptions are now subject to complete mutual simplification,
  3967     not just from left to right. The simplifier now preserves
  3968     the order of assumptions.
  3969 
  3970     Potential INCOMPATIBILITY:
  3971 
  3972     -- simp sometimes diverges where the old version did
  3973        not, e.g. invoking simp on the goal
  3974 
  3975         [| P (f x); y = x; f x = f y |] ==> Q
  3976 
  3977        now gives rise to the infinite reduction sequence
  3978 
  3979         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  3980 
  3981        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  3982        kind of problem.
  3983 
  3984     -- Tactics combining classical reasoner and simplification (such as auto)
  3985        are also affected by this change, because many of them rely on
  3986        simp. They may sometimes diverge as well or yield a different numbers
  3987        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  3988        in case of problems. Sometimes subsequent calls to the classical
  3989        reasoner will fail because a preceeding call to the simplifier too
  3990        eagerly simplified the goal, e.g. deleted redundant premises.
  3991 
  3992   - The simplifier trace now shows the names of the applied rewrite rules
  3993 
  3994   - You can limit the number of recursive invocations of the simplifier
  3995     during conditional rewriting (where the simplifie tries to solve the
  3996     conditions before applying the rewrite rule):
  3997     ML "simp_depth_limit := n"
  3998     where n is an integer. Thus you can force termination where previously
  3999     the simplifier would diverge.
  4000 
  4001   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4002 
  4003   - No longer aborts on failed congruence proof.  Instead, the
  4004     congruence is ignored.
  4005 
  4006 * Pure: New generic framework for extracting programs from constructive
  4007   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4008   as HOL/Extraction for some case studies.
  4009 
  4010 * Pure: The main goal of the proof state is no longer shown by default, only
  4011 the subgoals. This behaviour is controlled by a new flag.
  4012    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4013 (ML: Proof.show_main_goal).
  4014 
  4015 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4016 rules whose conclusion matches subgoal 1:
  4017       PG menu: Isabelle/Isar -> Show me -> matching rules
  4018 The rules are ordered by how closely they match the subgoal.
  4019 In particular, rules that solve a subgoal outright are displayed first
  4020 (or rather last, the way they are printed).
  4021 (ML: ProofGeneral.print_intros())
  4022 
  4023 * Pure: New flag trace_unify_fail causes unification to print
  4024 diagnostic information (PG: in trace buffer) when it fails. This is
  4025 useful for figuring out why single step proofs like rule, erule or
  4026 assumption failed.
  4027 
  4028 * Pure: Locale specifications now produce predicate definitions
  4029 according to the body of text (covering assumptions modulo local
  4030 definitions); predicate "loc_axioms" covers newly introduced text,
  4031 while "loc" is cumulative wrt. all included locale expressions; the
  4032 latter view is presented only on export into the global theory
  4033 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4034 on the old view without predicates;
  4035 
  4036 * Pure: predefined locales "var" and "struct" are useful for sharing
  4037 parameters (as in CASL, for example); just specify something like
  4038 ``var x + var y + struct M'' as import;
  4039 
  4040 * Pure: improved thms_containing: proper indexing of facts instead of
  4041 raw theorems; check validity of results wrt. current name space;
  4042 include local facts of proof configuration (also covers active
  4043 locales), cover fixed variables in index; may use "_" in term
  4044 specification; an optional limit for the number of printed facts may
  4045 be given (the default is 40);
  4046 
  4047 * Pure: disallow duplicate fact bindings within new-style theory files
  4048 (batch-mode only);
  4049 
  4050 * Provers: improved induct method: assumptions introduced by case
  4051 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4052 the goal statement); "foo" still refers to all facts collectively;
  4053 
  4054 * Provers: the function blast.overloaded has been removed: all constants
  4055 are regarded as potentially overloaded, which improves robustness in exchange
  4056 for slight decrease in efficiency;
  4057 
  4058 * Provers/linorder: New generic prover for transitivity reasoning over
  4059 linear orders.  Note: this prover is not efficient!
  4060 
  4061 * Isar: preview of problems to finish 'show' now produce an error
  4062 rather than just a warning (in interactive mode);
  4063 
  4064 
  4065 *** HOL ***
  4066 
  4067 * arith(_tac)
  4068 
  4069  - Produces a counter example if it cannot prove a goal.
  4070    Note that the counter example may be spurious if the goal is not a formula
  4071    of quantifier-free linear arithmetic.
  4072    In ProofGeneral the counter example appears in the trace buffer.
  4073 
  4074  - Knows about div k and mod k where k is a numeral of type nat or int.
  4075 
  4076  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4077    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4078    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4079 
  4080 * simp's arithmetic capabilities have been enhanced a bit: it now
  4081 takes ~= in premises into account (by performing a case split);
  4082 
  4083 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4084 are distributed over a sum of terms;
  4085 
  4086 * New tactic "trans_tac" and method "trans" instantiate
  4087 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4088 "<=", "<" and "=").
  4089 
  4090 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4091 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4092 
  4093 * 'typedef' command has new option "open" to suppress the set
  4094 definition;
  4095 
  4096 * functions Min and Max on finite sets have been introduced (theory
  4097 Finite_Set);
  4098 
  4099 * attribute [symmetric] now works for relations as well; it turns
  4100 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4101 
  4102 * induct over a !!-quantified statement (say !!x1..xn):
  4103   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4104 
  4105 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4106 %x. None. Warning: empty_def now refers to the previously hidden definition
  4107 of the empty set.
  4108 
  4109 * Algebra: formalization of classical algebra.  Intended as base for
  4110 any algebraic development in Isabelle.  Currently covers group theory
  4111 (up to Sylow's theorem) and ring theory (Universal Property of
  4112 Univariate Polynomials).  Contributions welcome;
  4113 
  4114 * GroupTheory: deleted, since its material has been moved to Algebra;
  4115 
  4116 * Complex: new directory of the complex numbers with numeric constants,
  4117 nonstandard complex numbers, and some complex analysis, standard and
  4118 nonstandard (Jacques Fleuriot);
  4119 
  4120 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4121 
  4122 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4123 Fleuriot);
  4124 
  4125 * Real/HahnBanach: updated and adapted to locales;
  4126 
  4127 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4128 Gray and Kramer);
  4129 
  4130 * UNITY: added the Meier-Sanders theory of progress sets;
  4131 
  4132 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4133 as abstract algorithms, instantiated to the JVM;
  4134 
  4135 * Bali: Java source language formalization. Type system, operational
  4136 semantics, axiomatic semantics. Supported language features:
  4137 classes, interfaces, objects,virtual methods, static methods,
  4138 static/instance fields, arrays, access modifiers, definite
  4139 assignment, exceptions.
  4140 
  4141 
  4142 *** ZF ***
  4143 
  4144 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4145 universe, etc.);
  4146 
  4147 * Main ZF: virtually all theories converted to new-style format;
  4148 
  4149 
  4150 *** ML ***
  4151 
  4152 * Pure: Tactic.prove provides sane interface for internal proofs;
  4153 omits the infamous "standard" operation, so this is more appropriate
  4154 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4155 
  4156 * Pure: improved error reporting of simprocs;
  4157 
  4158 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4159 up simprocs;
  4160 
  4161 
  4162 *** Document preparation ***
  4163 
  4164 * uses \par instead of \\ for line breaks in theory text. This may
  4165 shift some page breaks in large documents. To get the old behaviour
  4166 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4167 
  4168 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4169 other packages
  4170 
  4171 * \<euro> now needs package babel/greek instead of marvosym (which
  4172 broke \Rightarrow)
  4173 
  4174 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4175 textcomp package)
  4176 
  4177 
  4178 
  4179 New in Isabelle2002 (March 2002)
  4180 --------------------------------
  4181 
  4182 *** Document preparation ***
  4183 
  4184 * greatly simplified document preparation setup, including more
  4185 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4186 instructive isatool mkdir; users should basically be able to get
  4187 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4188 users may run a separate document processing stage manually like this:
  4189 "isatool usedir -D output HOL Test && isatool document Test/output";
  4190 
  4191 * theory dependency graph may now be incorporated into documents;
  4192 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4193 with \includegraphics of LaTeX;
  4194 
  4195 * proper spacing of consecutive markup elements, especially text
  4196 blocks after section headings;
  4197 
  4198 * support bold style (for single symbols only), input syntax is like
  4199 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4200 
  4201 * \<bullet> is now output as bold \cdot by default, which looks much
  4202 better in printed text;
  4203 
  4204 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4205 note that these symbols are currently unavailable in Proof General /
  4206 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4207 
  4208 * isatool latex no longer depends on changed TEXINPUTS, instead
  4209 isatool document copies the Isabelle style files to the target
  4210 location;
  4211 
  4212 
  4213 *** Isar ***
  4214 
  4215 * Pure/Provers: improved proof by cases and induction;
  4216   - 'case' command admits impromptu naming of parameters (such as
  4217     "case (Suc n)");
  4218   - 'induct' method divinates rule instantiation from the inductive
  4219     claim; no longer requires excessive ?P bindings for proper
  4220     instantiation of cases;
  4221   - 'induct' method properly enumerates all possibilities of set/type
  4222     rules; as a consequence facts may be also passed through *type*
  4223     rules without further ado;
  4224   - 'induct' method now derives symbolic cases from the *rulified*
  4225     rule (before it used to rulify cases stemming from the internal
  4226     atomized version); this means that the context of a non-atomic
  4227     statement becomes is included in the hypothesis, avoiding the
  4228     slightly cumbersome show "PROP ?case" form;
  4229   - 'induct' may now use elim-style induction rules without chaining
  4230     facts, using ``missing'' premises from the goal state; this allows
  4231     rules stemming from inductive sets to be applied in unstructured
  4232     scripts, while still benefitting from proper handling of non-atomic
  4233     statements; NB: major inductive premises need to be put first, all
  4234     the rest of the goal is passed through the induction;
  4235   - 'induct' proper support for mutual induction involving non-atomic
  4236     rule statements (uses the new concept of simultaneous goals, see
  4237     below);
  4238   - append all possible rule selections, but only use the first
  4239     success (no backtracking);
  4240   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4241   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4242   - added 'print_induct_rules' (covered by help item in recent Proof
  4243     General versions);
  4244   - moved induct/cases attributes to Pure, methods to Provers;
  4245   - generic method setup instantiated for FOL and HOL;
  4246 
  4247 * Pure: support multiple simultaneous goal statements, for example
  4248 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4249 meta-level mechanism, this acts as if several individual goals had
  4250 been stated separately; in particular common proof methods need to be
  4251 repeated in order to cover all claims; note that a single elimination
  4252 step is *not* sufficient to establish the two conjunctions, so this
  4253 fails:
  4254 
  4255   assume "A & B" then have A and B ..   (*".." fails*)
  4256 
  4257 better use "obtain" in situations as above; alternative refer to
  4258 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4259 
  4260 * Pure: proper integration with ``locales''; unlike the original
  4261 version by Florian Kammller, Isar locales package high-level proof
  4262 contexts rather than raw logical ones (e.g. we admit to include
  4263 attributes everywhere); operations on locales include merge and
  4264 rename; support for implicit arguments (``structures''); simultaneous
  4265 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4266 some examples;
  4267 
  4268 * Pure: the following commands have been ``localized'', supporting a
  4269 target locale specification "(in name)": 'lemma', 'theorem',
  4270 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4271 stored both within the locale and at the theory level (exported and
  4272 qualified by the locale name);
  4273 
  4274 * Pure: theory goals may now be specified in ``long'' form, with
  4275 ad-hoc contexts consisting of arbitrary locale elements. for example
  4276 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4277 definitions may be given, too); the result is a meta-level rule with
  4278 the context elements being discharged in the obvious way;
  4279 
  4280 * Pure: new proof command 'using' allows to augment currently used
  4281 facts after a goal statement ('using' is syntactically analogous to
  4282 'apply', but acts on the goal's facts only); this allows chained facts
  4283 to be separated into parts given before and after a claim, as in
  4284 ``from a and b have C using d and e <proof>'';
  4285 
  4286 * Pure: renamed "antecedent" case to "rule_context";
  4287 
  4288 * Pure: new 'judgment' command records explicit information about the
  4289 object-logic embedding (used by several tools internally); no longer
  4290 use hard-wired "Trueprop";
  4291 
  4292 * Pure: added 'corollary' command;
  4293 
  4294 * Pure: fixed 'token_translation' command;
  4295 
  4296 * Pure: removed obsolete 'exported' attribute;
  4297 
  4298 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4299 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4300 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4301 
  4302 * Pure: method 'atomize' presents local goal premises as object-level
  4303 statements (atomic meta-level propositions); setup controlled via
  4304 rewrite rules declarations of 'atomize' attribute; example
  4305 application: 'induct' method with proper rule statements in improper
  4306 proof *scripts*;
  4307 
  4308 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4309 now consider the syntactic context of assumptions, giving a better
  4310 chance to get type-inference of the arguments right (this is
  4311 especially important for locales);
  4312 
  4313 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4314 mode;
  4315 
  4316 * Pure/obtain: the formal conclusion "thesis", being marked as
  4317 ``internal'', may no longer be reference directly in the text;
  4318 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4319 situations;
  4320 
  4321 * Pure: generic 'sym' attribute which declares a rule both as pure
  4322 'elim?' and for the 'symmetric' operation;
  4323 
  4324 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4325 text; the fixed correlation with particular command syntax has been
  4326 discontinued;
  4327 
  4328 * Pure: new method 'rules' is particularly well-suited for proof
  4329 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4330 but often produces more compact proof terms with less detours;
  4331 
  4332 * Pure/Provers/classical: simplified integration with pure rule
  4333 attributes and methods; the classical "intro?/elim?/dest?"
  4334 declarations coincide with the pure ones; the "rule" method no longer
  4335 includes classically swapped intros; "intro" and "elim" methods no
  4336 longer pick rules from the context; also got rid of ML declarations
  4337 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4338 INCOMPATIBILITY;
  4339 
  4340 * Provers/classical: attribute 'swapped' produces classical inversions
  4341 of introduction rules;
  4342 
  4343 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4344 rules instead of full simplifier context; 'iff' attribute handles
  4345 conditional rules;
  4346 
  4347 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4348 
  4349 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4350 "(permissive)" option to recover old behavior;
  4351 
  4352 * HOL: 'inductive' no longer features separate (collective) attributes
  4353 for 'intros' (was found too confusing);
  4354 
  4355 * HOL: properly declared induction rules less_induct and
  4356 wf_induct_rule;
  4357 
  4358 
  4359 *** HOL ***
  4360 
  4361 * HOL: moved over to sane numeral syntax; the new policy is as
  4362 follows:
  4363 
  4364   - 0 and 1 are polymorphic constants, which are defined on any
  4365   numeric type (nat, int, real etc.);
  4366 
  4367   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4368   binary representation internally;
  4369 
  4370   - type nat has special constructor Suc, and generally prefers Suc 0
  4371   over 1::nat and Suc (Suc 0) over 2::nat;
  4372 
  4373 This change may cause significant problems of INCOMPATIBILITY; here
  4374 are some hints on converting existing sources:
  4375 
  4376   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4377   entities, so expressions involving "-" (unary or binary minus) need
  4378   to be spaced properly;
  4379 
  4380   - existing occurrences of "1" may need to be constraint "1::nat" or
  4381   even replaced by Suc 0; similar for old "2";
  4382 
  4383   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4384 
  4385   - remove all special provisions on numerals in proofs;
  4386 
  4387 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4388 representation (depends on bin_arith_simps in the default context);
  4389 
  4390 * HOL: symbolic syntax for x^2 (numeral 2);
  4391 
  4392 * HOL: the class of all HOL types is now called "type" rather than
  4393 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4394 in axclass/classes, instance/arities, and (usually rare) occurrences
  4395 in typings (of consts etc.); internally the class is called
  4396 "HOL.type", ML programs should refer to HOLogic.typeS;
  4397 
  4398 * HOL/record package improvements:
  4399   - new derived operations "fields" to build a partial record section,
  4400     "extend" to promote a fixed record to a record scheme, and
  4401     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4402     declared as simp by default;
  4403   - shared operations ("more", "fields", etc.) now need to be always
  4404     qualified) --- potential INCOMPATIBILITY;
  4405   - removed "make_scheme" operations (use "make" with "extend") --
  4406     INCOMPATIBILITY;
  4407   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4408   - provides cases/induct rules for use with corresponding Isar
  4409     methods (for concrete records, record schemes, concrete more
  4410     parts, and schematic more parts -- in that order);
  4411   - internal definitions directly based on a light-weight abstract
  4412     theory of product types over typedef rather than datatype;
  4413 
  4414 * HOL: generic code generator for generating executable ML code from
  4415 specifications; specific support for HOL constructs such as inductive
  4416 datatypes and sets, as well as recursive functions; can be invoked
  4417 via 'generate_code' theory section;
  4418 
  4419 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4420 
  4421 * HOL: consolidated and renamed several theories.  In particular:
  4422         Ord.thy has been absorbed into HOL.thy
  4423         String.thy has been absorbed into List.thy
  4424 
  4425 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4426 (beware of argument permutation!);
  4427 
  4428 * HOL: linorder_less_split superseded by linorder_cases;
  4429 
  4430 * HOL/List: "nodups" renamed to "distinct";
  4431 
  4432 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4433 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4434   - Ex_def has changed, now need to use some_eq_ex
  4435 
  4436 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4437 in this (rare) case use:
  4438 
  4439   delSWrapper "split_all_tac"
  4440   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4441 
  4442 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4443 MAY FAIL;
  4444 
  4445 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4446 Isabelle's type classes, ^ on functions and relations has too general
  4447 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4448 necessary to attach explicit type constraints;
  4449 
  4450 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4451 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4452 renamed accordingly (eg "compI" -> "rel_compI").
  4453 
  4454 * HOL: syntax translations now work properly with numerals and records
  4455 expressions;
  4456 
  4457 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4458 of "lam" -- INCOMPATIBILITY;
  4459 
  4460 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4461 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4462 renamed "Product_Type.unit";
  4463 
  4464 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4465 
  4466 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4467 the "cases" method);
  4468 
  4469 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4470 Florian Kammller);
  4471 
  4472 * HOL/IMP: updated and converted to new-style theory format; several
  4473 parts turned into readable document, with proper Isar proof texts and
  4474 some explanations (by Gerwin Klein);
  4475 
  4476 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4477 
  4478 * HOL-Hyperreal is now a logic image;
  4479 
  4480 
  4481 *** HOLCF ***
  4482 
  4483 * Isar: consts/constdefs supports mixfix syntax for continuous
  4484 operations;
  4485 
  4486 * Isar: domain package adapted to new-style theory format, e.g. see
  4487 HOLCF/ex/Dnat.thy;
  4488 
  4489 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4490 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4491 lift.induct_tac, always use UU instead of Undef;
  4492 
  4493 * HOLCF/IMP: updated and converted to new-style theory;
  4494 
  4495 
  4496 *** ZF ***
  4497 
  4498 * Isar: proper integration of logic-specific tools and packages,
  4499 including theory commands '(co)inductive', '(co)datatype',
  4500 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4501 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4502 
  4503 * theory Main no longer includes AC; for the Axiom of Choice, base
  4504 your theory on Main_ZFC;
  4505 
  4506 * the integer library now covers quotients and remainders, with many
  4507 laws relating division to addition, multiplication, etc.;
  4508 
  4509 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4510 typeless version of the formalism;
  4511 
  4512 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4513 format;
  4514 
  4515 * ZF/Induct: new directory for examples of inductive definitions,
  4516 including theory Multiset for multiset orderings; converted to
  4517 new-style theory format;
  4518 
  4519 * ZF: many new theorems about lists, ordinals, etc.;
  4520 
  4521 
  4522 *** General ***
  4523 
  4524 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4525 variable proof controls level of detail: 0 = no proofs (only oracle
  4526 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4527 also ref manual for further ML interfaces;
  4528 
  4529 * Pure/axclass: removed obsolete ML interface
  4530 goal_subclass/goal_arity;
  4531 
  4532 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4533 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4534 separate tokens, so expressions involving minus need to be spaced
  4535 properly;
  4536 
  4537 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4538 rather than "infixl" or "infixr";
  4539 
  4540 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4541 sort constraint specifications in type inference; e.g. "x::_::foo"
  4542 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4543 type variable);
  4544 
  4545 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4546 control output of nested => (types); the default behavior is
  4547 "type_brackets";
  4548 
  4549 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4550 tokens into AST constants;
  4551 
  4552 * Pure/syntax: prefer later declarations of translations and print
  4553 translation functions; potential INCOMPATIBILITY: need to reverse
  4554 multiple declarations for same syntax element constant;
  4555 
  4556 * Pure/show_hyps reset by default (in accordance to existing Isar
  4557 practice);
  4558 
  4559 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4560 addSafter;
  4561 
  4562 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4563 as well;
  4564 
  4565 * system: tested support for MacOS X; should be able to get Isabelle +
  4566 Proof General to work in a plain Terminal after installing Poly/ML
  4567 (e.g. from the Isabelle distribution area) and GNU bash alone
  4568 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4569 support requires further installations, e.g. from
  4570 http://fink.sourceforge.net/);
  4571 
  4572 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4573 
  4574 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4575 of 40 MB), cf. ML_OPTIONS;
  4576 
  4577 * system: Proof General keywords specification is now part of the
  4578 Isabelle distribution (see etc/isar-keywords.el);
  4579 
  4580 * system: support for persistent Proof General sessions (refrain from
  4581 outdating all loaded theories on startup); user may create writable
  4582 logic images like this: ``isabelle -q HOL Test'';
  4583 
  4584 * system: smart selection of Isabelle process versus Isabelle
  4585 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4586 run both "isabelle" and "Isabelle" even if file names are badly
  4587 damaged (executable inspects the case of the first letter of its own
  4588 name); added separate "isabelle-process" and "isabelle-interface";
  4589 
  4590 * system: refrain from any attempt at filtering input streams; no
  4591 longer support ``8bit'' encoding of old isabelle font, instead proper
  4592 iso-latin characters may now be used; the related isatools
  4593 "symbolinput" and "nonascii" have disappeared as well;
  4594 
  4595 * system: removed old "xterm" interface (the print modes "xterm" and
  4596 "xterm_color" are still available for direct use in a suitable
  4597 terminal);
  4598 
  4599 
  4600 
  4601 New in Isabelle99-2 (February 2001)
  4602 -----------------------------------
  4603 
  4604 *** Overview of INCOMPATIBILITIES ***
  4605 
  4606 * HOL: please note that theories in the Library and elsewhere often use the
  4607 new-style (Isar) format; to refer to their theorems in an ML script you must
  4608 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4609 
  4610 * HOL: inductive package no longer splits induction rule aggressively,
  4611 but only as far as specified by the introductions given; the old
  4612 format may be recovered via ML function complete_split_rule or attribute
  4613 'split_rule (complete)';
  4614 
  4615 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4616 gfp_Tarski to gfp_unfold;
  4617 
  4618 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4619 
  4620 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4621 relation); infix "^^" has been renamed "``"; infix "``" has been
  4622 renamed "`"; "univalent" has been renamed "single_valued";
  4623 
  4624 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4625 operation;
  4626 
  4627 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4628 
  4629 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4630 
  4631 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4632 consequence, it is no longer monotonic wrt. the local goal context
  4633 (which is now passed through the inductive cases);
  4634 
  4635 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4636 \<gg> to \<ggreater>;
  4637 
  4638 
  4639 *** Document preparation ***
  4640 
  4641 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4642 available: are "it" for near math-mode best-style output, "sl" for
  4643 slanted text style, and "tt" for plain type-writer; if no
  4644 \isabellestyle command is given, output is according to slanted
  4645 type-writer);
  4646 
  4647 * support sub/super scripts (for single symbols only), input syntax is
  4648 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4649 
  4650 * some more standard symbols; see Appendix A of the system manual for
  4651 the complete list of symbols defined in isabellesym.sty;
  4652 
  4653 * improved isabelle style files; more abstract symbol implementation
  4654 (should now use \isamath{...} and \isatext{...} in custom symbol
  4655 definitions);
  4656 
  4657 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4658 state; Note that presentation of goal states does not conform to
  4659 actual human-readable proof documents.  Please do not include goal
  4660 states into document output unless you really know what you are doing!
  4661 
  4662 * proper indentation of antiquoted output with proportional LaTeX
  4663 fonts;
  4664 
  4665 * no_document ML operator temporarily disables LaTeX document
  4666 generation;
  4667 
  4668 * isatool unsymbolize tunes sources for plain ASCII communication;
  4669 
  4670 
  4671 *** Isar ***
  4672 
  4673 * Pure: Isar now suffers initial goal statements to contain unbound
  4674 schematic variables (this does not conform to actual readable proof
  4675 documents, due to unpredictable outcome and non-compositional proof
  4676 checking); users who know what they are doing may use schematic goals
  4677 for Prolog-style synthesis of proven results;
  4678 
  4679 * Pure: assumption method (an implicit finishing) now handles actual
  4680 rules as well;
  4681 
  4682 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4683 initial goal, declare "that" only as Pure intro (only for single
  4684 steps); the "that" rule assumption may now be involved in implicit
  4685 finishing, thus ".." becomes a feasible for trivial obtains;
  4686 
  4687 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4688 instance proofs may be performed by "..";
  4689 
  4690 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4691 statements as well;
  4692 
  4693 * Pure: more robust selection of calculational rules;
  4694 
  4695 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4696 rule (as well as the assumption rule);
  4697 
  4698 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4699 lemmas, using the graph browser tool;
  4700 
  4701 * Pure: predict failure of "show" in interactive mode;
  4702 
  4703 * Pure: 'thms_containing' now takes actual terms as arguments;
  4704 
  4705 * HOL: improved method 'induct' --- now handles non-atomic goals
  4706 (potential INCOMPATIBILITY); tuned error handling;
  4707 
  4708 * HOL: cases and induct rules now provide explicit hints about the
  4709 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4710 any remaining facts are inserted into the goal verbatim;
  4711 
  4712 * HOL: local contexts (aka cases) may now contain term bindings as
  4713 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4714 the result to be shown in each case;
  4715 
  4716 * HOL: added 'recdef_tc' command;
  4717 
  4718 * isatool convert assists in eliminating legacy ML scripts;
  4719 
  4720 
  4721 *** HOL ***
  4722 
  4723 * HOL/Library: a collection of generic theories to be used together
  4724 with main HOL; the theory loader path already includes this directory
  4725 by default; the following existing theories have been moved here:
  4726 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4727 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4728 
  4729 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4730 modelling and verification task performed in Isabelle/HOL +
  4731 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4732 
  4733 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4734 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4735 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4736 'domain', this makes the theory consistent with mathematical
  4737 literature;
  4738 
  4739 * HOL basics: added overloaded operations "inverse" and "divide"
  4740 (infix "/"), syntax for generic "abs" operation, generic summation
  4741 operator \<Sum>;
  4742 
  4743 * HOL/typedef: simplified package, provide more useful rules (see also
  4744 HOL/subset.thy);
  4745 
  4746 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4747 now expressed as a proper nested rule (old-style tactic scripts may
  4748 require atomize_strip_tac to cope with non-atomic premises);
  4749 
  4750 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4751 to "split_conv" (old name still available for compatibility);
  4752 
  4753 * HOL: improved concrete syntax for strings (e.g. allows translation
  4754 rules with string literals);
  4755 
  4756 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4757  and Fleuriot's mechanization of analysis, including the transcendental
  4758  functions for the reals;
  4759 
  4760 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4761 
  4762 
  4763 *** CTT ***
  4764 
  4765 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4766 "lam" is displayed as TWO lambda-symbols
  4767 
  4768 * CTT: theory Main now available, containing everything (that is, Bool
  4769 and Arith);
  4770 
  4771 
  4772 *** General ***
  4773 
  4774 * Pure: the Simplifier has been implemented properly as a derived rule
  4775 outside of the actual kernel (at last!); the overall performance
  4776 penalty in practical applications is about 50%, while reliability of
  4777 the Isabelle inference kernel has been greatly improved;
  4778 
  4779 * print modes "brackets" and "no_brackets" control output of nested =>
  4780 (types) and ==> (props); the default behaviour is "brackets";
  4781 
  4782 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4783 as assumptions as well;
  4784 
  4785 * system: support Poly/ML 4.0;
  4786 
  4787 * system: isatool install handles KDE version 1 or 2;
  4788 
  4789 
  4790 
  4791 New in Isabelle99-1 (October 2000)
  4792 ----------------------------------
  4793 
  4794 *** Overview of INCOMPATIBILITIES ***
  4795 
  4796 * HOL: simplification of natural numbers is much changed; to partly
  4797 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4798 issue the following ML commands:
  4799 
  4800   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4801   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4802 
  4803 * HOL: simplification no longer dives into case-expressions; this is
  4804 controlled by "t.weak_case_cong" for each datatype t;
  4805 
  4806 * HOL: nat_less_induct renamed to less_induct;
  4807 
  4808 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4809 fixsome to patch .thy and .ML sources automatically;
  4810 
  4811   select_equality  -> some_equality
  4812   select_eq_Ex     -> some_eq_ex
  4813   selectI2EX       -> someI2_ex
  4814   selectI2         -> someI2
  4815   selectI          -> someI
  4816   select1_equality -> some1_equality
  4817   Eps_sym_eq       -> some_sym_eq_trivial
  4818   Eps_eq           -> some_eq_trivial
  4819 
  4820 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4821 
  4822 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4823 instead);
  4824 
  4825 * HOL: the recursion equations generated by 'recdef' are now called
  4826 f.simps instead of f.rules;
  4827 
  4828 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4829 
  4830 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4831 sometimes be needed;
  4832 
  4833 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4834 
  4835 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4836 
  4837 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4838 product is now "<*>" instead of "Times"; the lexicographic product is
  4839 now "<*lex*>" instead of "**";
  4840 
  4841 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4842 of main HOL, but was unused); better use HOL's datatype package;
  4843 
  4844 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4845 the old syntax may be recovered as follows:
  4846 
  4847   syntax (symbols)
  4848     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4849       (infixl "\\<oplus>" 100)
  4850 
  4851 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4852 
  4853 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4854 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4855 internally;
  4856 
  4857 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4858 changed from A/r to A//r;
  4859 
  4860 * ZF: new treatment of arithmetic (nat & int) may break some old
  4861 proofs;
  4862 
  4863 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4864 rulify -> rule_format, elimify -> elim_format, ...);
  4865 
  4866 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4867 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4868 should have to change intro!! to intro? only); replaced "delrule" by
  4869 "rule del";
  4870 
  4871 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4872 
  4873 * Provers: strengthened force_tac by using new first_best_tac;
  4874 
  4875 * LaTeX document preparation: several changes of isabelle.sty (see
  4876 lib/texinputs);
  4877 
  4878 
  4879 *** Document preparation ***
  4880 
  4881 * formal comments (text blocks etc.) in new-style theories may now
  4882 contain antiquotations of thm/prop/term/typ/text to be presented
  4883 according to latex print mode; concrete syntax is like this:
  4884 @{term[show_types] "f(x) = a + x"};
  4885 
  4886 * isatool mkdir provides easy setup of Isabelle session directories,
  4887 including proper document sources;
  4888 
  4889 * generated LaTeX sources are now deleted after successful run
  4890 (isatool document -c); may retain a copy somewhere else via -D option
  4891 of isatool usedir;
  4892 
  4893 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  4894 style files, achieving self-contained LaTeX sources and simplifying
  4895 LaTeX debugging;
  4896 
  4897 * old-style theories now produce (crude) LaTeX output as well;
  4898 
  4899 * browser info session directories are now self-contained (may be put
  4900 on WWW server seperately); improved graphs of nested sessions; removed
  4901 graph for 'all sessions';
  4902 
  4903 * several improvements in isabelle style files; \isabellestyle{it}
  4904 produces fake math mode output; \isamarkupheader is now \section by
  4905 default; see lib/texinputs/isabelle.sty etc.;
  4906 
  4907 
  4908 *** Isar ***
  4909 
  4910 * Isar/Pure: local results and corresponding term bindings are now
  4911 subject to Hindley-Milner polymorphism (similar to ML); this
  4912 accommodates incremental type-inference very nicely;
  4913 
  4914 * Isar/Pure: new derived language element 'obtain' supports
  4915 generalized existence reasoning;
  4916 
  4917 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  4918 support accumulation of results, without applying any rules yet;
  4919 useful to collect intermediate results without explicit name
  4920 references, and for use with transitivity rules with more than 2
  4921 premises;
  4922 
  4923 * Isar/Pure: scalable support for case-analysis type proofs: new
  4924 'case' language element refers to local contexts symbolically, as
  4925 produced by certain proof methods; internally, case names are attached
  4926 to theorems as "tags";
  4927 
  4928 * Isar/Pure: theory command 'hide' removes declarations from
  4929 class/type/const name spaces;
  4930 
  4931 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  4932 indicate potential overloading;
  4933 
  4934 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  4935 
  4936 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  4937 "{a,b,c}" instead of {a,b,c};
  4938 
  4939 * Isar/Pure now provides its own version of intro/elim/dest
  4940 attributes; useful for building new logics, but beware of confusion
  4941 with the version in Provers/classical;
  4942 
  4943 * Isar/Pure: the local context of (non-atomic) goals is provided via
  4944 case name 'antecedent';
  4945 
  4946 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  4947 to the current context is now done automatically);
  4948 
  4949 * Isar/Pure: theory command 'method_setup' provides a simple interface
  4950 for definining proof methods in ML;
  4951 
  4952 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4953 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  4954 most cases, one should have to change intro!! to intro? only);
  4955 replaced "delrule" by "rule del";
  4956 
  4957 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  4958 'symmetric' attribute (the latter supercedes [RS sym]);
  4959 
  4960 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  4961 method modifier); 'simp' method: 'only:' modifier removes loopers as
  4962 well (including splits);
  4963 
  4964 * Isar/Provers: Simplifier and Classical methods now support all kind
  4965 of modifiers used in the past, including 'cong', 'iff', etc.
  4966 
  4967 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  4968 of Simplifier and Classical reasoner);
  4969 
  4970 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  4971 now support named cases; major packages (inductive, datatype, primrec,
  4972 recdef) support case names and properly name parameters;
  4973 
  4974 * Isar/HOL: new transitivity rules for substitution in inequalities --
  4975 monotonicity conditions are extracted to be proven at end of
  4976 calculations;
  4977 
  4978 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  4979 method anyway;
  4980 
  4981 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  4982 split_if split_if_asm; datatype package provides theorems foo.splits =
  4983 foo.split foo.split_asm for each datatype;
  4984 
  4985 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  4986 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  4987 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  4988 use "(cases (simplified))" method in proper proof texts);
  4989 
  4990 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  4991 
  4992 * Isar: names of theorems etc. may be natural numbers as well;
  4993 
  4994 * Isar: 'pr' command: optional arguments for goals_limit and
  4995 ProofContext.prems_limit; no longer prints theory contexts, but only
  4996 proof states;
  4997 
  4998 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  4999 additional print modes to be specified; e.g. "pr(latex)" will print
  5000 proof state according to the Isabelle LaTeX style;
  5001 
  5002 * Isar: improved support for emulating tactic scripts, including proof
  5003 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5004 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5005 (for HOL datatypes);
  5006 
  5007 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5008 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5009 'proof method scripts' have to be in depth-first order;
  5010 
  5011 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5012 
  5013 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5014 should instead use individual commands for printing items
  5015 (print_commands, print_methods etc.);
  5016 
  5017 * Isar: added 'nothing' --- the empty list of theorems;
  5018 
  5019 
  5020 *** HOL ***
  5021 
  5022 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5023 corresponding virtual machine and a specification of its bytecode
  5024 verifier and a lightweight bytecode verifier, including proofs of
  5025 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5026 Cornelia Pusch (see also the homepage of project Bali at
  5027 http://isabelle.in.tum.de/Bali/);
  5028 
  5029 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5030 Clemens Ballarin;
  5031 
  5032 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5033 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5034 Rasmussen;
  5035 
  5036 * HOL/Lattice: fundamental concepts of lattice theory and order
  5037 structures, including duals, properties of bounds versus algebraic
  5038 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5039 Theorem for complete lattices etc.; may also serve as a demonstration
  5040 for abstract algebraic reasoning using axiomatic type classes, and
  5041 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5042 
  5043 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5044 von Oheimb;
  5045 
  5046 * HOL/IMPP: extension of IMP with local variables and mutually
  5047 recursive procedures, by David von Oheimb;
  5048 
  5049 * HOL/Lambda: converted into new-style theory and document;
  5050 
  5051 * HOL/ex/Multiquote: example of multiple nested quotations and
  5052 anti-quotations -- basically a generalized version of de-Bruijn
  5053 representation; very useful in avoiding lifting of operations;
  5054 
  5055 * HOL/record: added general record equality rule to simpset; fixed
  5056 select-update simplification procedure to handle extended records as
  5057 well; admit "r" as field name;
  5058 
  5059 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5060 other numeric types and also as the identity of groups, rings, etc.;
  5061 
  5062 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5063 Types nat and int belong to this axclass;
  5064 
  5065 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5066    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5067    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5068   two terms #m*u and #n*u are replaced by #(m+n)*u
  5069     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5070   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5071     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5072 
  5073 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5074 powerful prover for predicate logic but knows nothing of clasets; see
  5075 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5076 
  5077 * HOL: new version of "case_tac" subsumes both boolean case split and
  5078 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5079 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5080 
  5081 * HOL: simplification no longer dives into case-expressions: only the
  5082 selector expression is simplified, but not the remaining arms; to
  5083 enable full simplification of case-expressions for datatype t, you may
  5084 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5085 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5086 
  5087 * HOL/recdef: the recursion equations generated by 'recdef' for
  5088 function 'f' are now called f.simps instead of f.rules; if all
  5089 termination conditions are proved automatically, these simplification
  5090 rules are added to the simpset, as in primrec; rules may be named
  5091 individually as well, resulting in a separate list of theorems for
  5092 each equation;
  5093 
  5094 * HOL/While is a new theory that provides a while-combinator. It
  5095 permits the definition of tail-recursive functions without the
  5096 provision of a termination measure. The latter is necessary once the
  5097 invariant proof rule for while is applied.
  5098 
  5099 * HOL: new (overloaded) notation for the set of elements below/above
  5100 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5101 
  5102 * HOL: theorems impI, allI, ballI bound as "strip";
  5103 
  5104 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5105 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5106 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5107 
  5108 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5109 
  5110 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5111 main HOL, but was unused);
  5112 
  5113 * HOL: fewer consts declared as global (e.g. have to refer to
  5114 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5115 
  5116 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5117 in case of overlap with user translations (e.g. judgements over
  5118 tuples); (note that the underlying logical represenation is still
  5119 bogus);
  5120 
  5121 
  5122 *** ZF ***
  5123 
  5124 * ZF: simplification automatically cancels common terms in arithmetic
  5125 expressions over nat and int;
  5126 
  5127 * ZF: new treatment of nat to minimize type-checking: all operators
  5128 coerce their operands to a natural number using the function natify,
  5129 making the algebraic laws unconditional;
  5130 
  5131 * ZF: as above, for int: operators coerce their operands to an integer
  5132 using the function intify;
  5133 
  5134 * ZF: the integer library now contains many of the usual laws for the
  5135 orderings, including $<=, and monotonicity laws for $+ and $*;
  5136 
  5137 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5138 simplification;
  5139 
  5140 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5141 to the simplifier and classical reasoner simultaneously;
  5142 
  5143 
  5144 *** General ***
  5145 
  5146 * Provers: blast_tac now handles actual object-logic rules as
  5147 assumptions; note that auto_tac uses blast_tac internally as well;
  5148 
  5149 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5150 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5151 
  5152 * Provers: delrules now handles destruct rules as well (no longer need
  5153 explicit make_elim);
  5154 
  5155 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5156   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5157 use instead the strong form,
  5158   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5159 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5160 from destruct-rules;
  5161 
  5162 * Provers: Simplifier.easy_setup provides a fast path to basic
  5163 Simplifier setup for new object-logics;
  5164 
  5165 * Pure: AST translation rules no longer require constant head on LHS;
  5166 
  5167 * Pure: improved name spaces: ambiguous output is qualified; support
  5168 for hiding of names;
  5169 
  5170 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5171 XSYMBOL_HOME; no longer need to do manual configuration in most
  5172 situations;
  5173 
  5174 * system: compression of ML heaps images may now be controlled via -c
  5175 option of isabelle and isatool usedir (currently only observed by
  5176 Poly/ML);
  5177 
  5178 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5179 useful for remote X11);
  5180 
  5181 * system: provide TAGS file for Isabelle sources;
  5182 
  5183 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5184 order;
  5185 
  5186 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5187 timing flag supersedes proof_timing and Toplevel.trace;
  5188 
  5189 * ML: new combinators |>> and |>>> for incremental transformations
  5190 with secondary results (e.g. certain theory extensions):
  5191 
  5192 * ML: PureThy.add_defs gets additional argument to indicate potential
  5193 overloading (usually false);
  5194 
  5195 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5196 results;
  5197 
  5198 
  5199 
  5200 New in Isabelle99 (October 1999)
  5201 --------------------------------
  5202 
  5203 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5204 
  5205 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5206 are no longer simplified.  (This allows the simplifier to unfold recursive
  5207 functional programs.)  To restore the old behaviour, declare
  5208 
  5209     Delcongs [if_weak_cong];
  5210 
  5211 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5212 complement;
  5213 
  5214 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5215 
  5216 * HOL/datatype: mutual_induct_tac no longer exists --
  5217   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5218 
  5219 * HOL/typedef: fixed type inference for representing set; type
  5220 arguments now have to occur explicitly on the rhs as type constraints;
  5221 
  5222 * ZF: The con_defs part of an inductive definition may no longer refer
  5223 to constants declared in the same theory;
  5224 
  5225 * HOL, ZF: the function mk_cases, generated by the inductive
  5226 definition package, has lost an argument.  To simplify its result, it
  5227 uses the default simpset instead of a supplied list of theorems.
  5228 
  5229 * HOL/List: the constructors of type list are now Nil and Cons;
  5230 
  5231 * Simplifier: the type of the infix ML functions
  5232         setSSolver addSSolver setSolver addSolver
  5233 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5234 for packaging solvers. A solver is created via
  5235         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5236 where the string argument is only a comment.
  5237 
  5238 
  5239 *** Proof tools ***
  5240 
  5241 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5242 decision procedure for linear arithmetic. Currently it is used for
  5243 types `nat', `int', and `real' in HOL (see below); it can, should and
  5244 will be instantiated for other types and logics as well.
  5245 
  5246 * The simplifier now accepts rewrite rules with flexible heads, eg
  5247      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5248   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5249   matching.
  5250 
  5251 
  5252 *** General ***
  5253 
  5254 * New Isabelle/Isar subsystem provides an alternative to traditional
  5255 tactical theorem proving; together with the ProofGeneral/isar user
  5256 interface it offers an interactive environment for developing human
  5257 readable proof documents (Isar == Intelligible semi-automated
  5258 reasoning); for further information see isatool doc isar-ref,
  5259 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5260 
  5261 * improved and simplified presentation of theories: better HTML markup
  5262 (including colors), graph views in several sizes; isatool usedir now
  5263 provides a proper interface for user theories (via -P option); actual
  5264 document preparation based on (PDF)LaTeX is available as well (for
  5265 new-style theories only); see isatool doc system for more information;
  5266 
  5267 * native support for Proof General, both for classic Isabelle and
  5268 Isabelle/Isar;
  5269 
  5270 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5271 using the graph browser tool;
  5272 
  5273 * Isabelle manuals now also available as PDF;
  5274 
  5275 * theory loader rewritten from scratch (may not be fully
  5276 bug-compatible); old loadpath variable has been replaced by show_path,
  5277 add_path, del_path, reset_path functions; new operations such as
  5278 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5279 isatool doc ref);
  5280 
  5281 * improved isatool install: option -k creates KDE application icon,
  5282 option -p DIR installs standalone binaries;
  5283 
  5284 * added ML_PLATFORM setting (useful for cross-platform installations);
  5285 more robust handling of platform specific ML images for SML/NJ;
  5286 
  5287 * the settings environment is now statically scoped, i.e. it is never
  5288 created again in sub-processes invoked from isabelle, isatool, or
  5289 Isabelle;
  5290 
  5291 * path element specification '~~' refers to '$ISABELLE_HOME';
  5292 
  5293 * in locales, the "assumes" and "defines" parts may be omitted if
  5294 empty;
  5295 
  5296 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5297 long arrows);
  5298 
  5299 * new print_mode "HTML";
  5300 
  5301 * new flag show_tags controls display of tags of theorems (which are
  5302 basically just comments that may be attached by some tools);
  5303 
  5304 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5305 mode and goal output format:
  5306 
  5307 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5308 244c244
  5309 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5310 ---
  5311 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5312 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5313 181c181
  5314 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5315 ---
  5316 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5317 
  5318 * function bind_thms stores lists of theorems (cf. bind_thm);
  5319 
  5320 * new shorthand tactics ftac, eatac, datac, fatac;
  5321 
  5322 * qed (and friends) now accept "" as result name; in that case the
  5323 theorem is not stored, but proper checks and presentation of the
  5324 result still apply;
  5325 
  5326 * theorem database now also indexes constants "Trueprop", "all",
  5327 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5328 
  5329 
  5330 *** HOL ***
  5331 
  5332 ** HOL arithmetic **
  5333 
  5334 * There are now decision procedures for linear arithmetic over nat and
  5335 int:
  5336 
  5337 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5338 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5339 are treated as atomic; subformulae not involving type `nat' or `int'
  5340 are ignored; quantified subformulae are ignored unless they are
  5341 positive universal or negative existential. The tactic has to be
  5342 invoked by hand and can be a little bit slow. In particular, the
  5343 running time is exponential in the number of occurrences of `min' and
  5344 `max', and `-' on `nat'.
  5345 
  5346 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5347 (negated) (in)equalities among the premises and the conclusion into
  5348 account (i.e. no compound formulae) and does not know about `min' and
  5349 `max', and `-' on `nat'. It is fast and is used automatically by the
  5350 simplifier.
  5351 
  5352 NB: At the moment, these decision procedures do not cope with mixed
  5353 nat/int formulae where the two parts interact, such as `m < n ==>
  5354 int(m) < int(n)'.
  5355 
  5356 * HOL/Numeral provides a generic theory of numerals (encoded
  5357 efficiently as bit strings); setup for types nat/int/real is in place;
  5358 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5359 int, existing theories and proof scripts may require a few additional
  5360 type constraints;
  5361 
  5362 * integer division and remainder can now be performed on constant
  5363 arguments;
  5364 
  5365 * many properties of integer multiplication, division and remainder
  5366 are now available;
  5367 
  5368 * An interface to the Stanford Validity Checker (SVC) is available through the
  5369 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5370 are proved automatically.  SVC must be installed separately, and its results
  5371 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5372 invocation of the underlying oracle).  For SVC see
  5373   http://verify.stanford.edu/SVC
  5374 
  5375 * IsaMakefile: the HOL-Real target now builds an actual image;
  5376 
  5377 
  5378 ** HOL misc **
  5379 
  5380 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5381 (in Isabelle/Isar) -- by Gertrud Bauer;
  5382 
  5383 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5384 analysis for assembly languages with subtypes;
  5385 
  5386 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5387 -- avoids syntactic ambiguities and treats state, transition, and
  5388 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5389 changed syntax and (many) tactics;
  5390 
  5391 * HOL/inductive: Now also handles more general introduction rules such
  5392   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5393   theorems are now maintained within the theory (maintained via the
  5394   "mono" attribute);
  5395 
  5396 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5397   (using function types) such as
  5398 
  5399   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5400 
  5401 * HOL/record: record_simproc (part of the default simpset) takes care
  5402 of selectors applied to updated records; record_split_tac is no longer
  5403 part of the default claset; update_defs may now be removed from the
  5404 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5405 
  5406   claset_ref () := claset() addSWrapper record_split_wrapper;
  5407   Delsimprocs [record_simproc]
  5408 
  5409 * HOL/typedef: fixed type inference for representing set; type
  5410 arguments now have to occur explicitly on the rhs as type constraints;
  5411 
  5412 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5413 names rather than an ML expression;
  5414 
  5415 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5416 supplied later.  Program schemes can be defined, such as
  5417     "While B C s = (if B s then While B C (C s) else s)"
  5418 where the well-founded relation can be chosen after B and C have been given.
  5419 
  5420 * HOL/List: the constructors of type list are now Nil and Cons;
  5421 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5422 course, ML tools referring to List.list.op # etc. have to be adapted;
  5423 
  5424 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5425 disabled by default; run isabelle with option -m HOL to get back to
  5426 the original Gordon/HOL-style output;
  5427 
  5428 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5429 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5430 
  5431 * HOL basic syntax simplified (more orthogonal): all variants of
  5432 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5433 Eps operator is provided as well: "SOME x. P[x]";
  5434 
  5435 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5436 
  5437 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5438 thus available for user theories;
  5439 
  5440 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5441 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5442 time;
  5443 
  5444 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5445 several times and then mp;
  5446 
  5447 
  5448 *** LK ***
  5449 
  5450 * the notation <<...>> is now available as a notation for sequences of
  5451 formulas;
  5452 
  5453 * the simplifier is now installed
  5454 
  5455 * the axiom system has been generalized (thanks to Soren Heilmann)
  5456 
  5457 * the classical reasoner now has a default rule database
  5458 
  5459 
  5460 *** ZF ***
  5461 
  5462 * new primrec section allows primitive recursive functions to be given
  5463 directly (as in HOL) over datatypes and the natural numbers;
  5464 
  5465 * new tactics induct_tac and exhaust_tac for induction (or case
  5466 analysis) over datatypes and the natural numbers;
  5467 
  5468 * the datatype declaration of type T now defines the recursor T_rec;
  5469 
  5470 * simplification automatically does freeness reasoning for datatype
  5471 constructors;
  5472 
  5473 * automatic type-inference, with AddTCs command to insert new
  5474 type-checking rules;
  5475 
  5476 * datatype introduction rules are now added as Safe Introduction rules
  5477 to the claset;
  5478 
  5479 * the syntax "if P then x else y" is now available in addition to
  5480 if(P,x,y);
  5481 
  5482 
  5483 *** Internal programming interfaces ***
  5484 
  5485 * tuned simplifier trace output; new flag debug_simp;
  5486 
  5487 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5488 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5489 
  5490 * AxClass.axclass_tac lost the theory argument;
  5491 
  5492 * tuned current_goals_markers semantics: begin / end goal avoids
  5493 printing empty lines;
  5494 
  5495 * removed prs and prs_fn hook, which was broken because it did not
  5496 include \n in its semantics, forcing writeln to add one
  5497 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5498 string -> unit if you really want to output text without newline;
  5499 
  5500 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5501 plain output, interface builders may have to enable 'isabelle_font'
  5502 mode to get Isabelle font glyphs as before;
  5503 
  5504 * refined token_translation interface; INCOMPATIBILITY: output length
  5505 now of type real instead of int;
  5506 
  5507 * theory loader actions may be traced via new ThyInfo.add_hook
  5508 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5509 your own database of information attached to *whole* theories -- as
  5510 opposed to intra-theory data slots offered via TheoryDataFun;
  5511 
  5512 * proper handling of dangling sort hypotheses (at last!);
  5513 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5514 extra sort hypotheses that can be witnessed from the type signature;
  5515 the force_strip_shyps flag is gone, any remaining shyps are simply
  5516 left in the theorem (with a warning issued by strip_shyps_warning);
  5517 
  5518 
  5519 
  5520 New in Isabelle98-1 (October 1998)
  5521 ----------------------------------
  5522 
  5523 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5524 
  5525 * several changes of automated proof tools;
  5526 
  5527 * HOL: major changes to the inductive and datatype packages, including
  5528 some minor incompatibilities of theory syntax;
  5529 
  5530 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5531 called `inj_on';
  5532 
  5533 * HOL: removed duplicate thms in Arith:
  5534   less_imp_add_less  should be replaced by  trans_less_add1
  5535   le_imp_add_le      should be replaced by  trans_le_add1
  5536 
  5537 * HOL: unary minus is now overloaded (new type constraints may be
  5538 required);
  5539 
  5540 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5541 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5542 now taken as an integer constant.
  5543 
  5544 * Pure: ML function 'theory_of' renamed to 'theory';
  5545 
  5546 
  5547 *** Proof tools ***
  5548 
  5549 * Simplifier:
  5550   1. Asm_full_simp_tac is now more aggressive.
  5551      1. It will sometimes reorient premises if that increases their power to
  5552         simplify.
  5553      2. It does no longer proceed strictly from left to right but may also
  5554         rotate premises to achieve further simplification.
  5555      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5556      old Asm_full_simp_tac in that it does not rotate premises.
  5557   2. The simplifier now knows a little bit about nat-arithmetic.
  5558 
  5559 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5560 allows for selected deletion of wrappers, by introduction of names for
  5561 wrapper functionals.  This implies that addbefore, addSbefore,
  5562 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5563 and that adding two tactics with the same name overwrites the first
  5564 one (emitting a warning).
  5565   type wrapper = (int -> tactic) -> (int -> tactic)
  5566   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5567   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5568   delWrapper, delSWrapper: claset *  string            -> claset
  5569   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5570 
  5571 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5572 semantics; addbefore now affects only the unsafe part of step_tac
  5573 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5574 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5575 by Force_tac;
  5576 
  5577 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5578 compWrapper; added safe wrapper (and access functions for it);
  5579 
  5580 * HOL/split_all_tac is now much faster and fails if there is nothing
  5581 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5582 and the names of the automatically generated variables have changed.
  5583 split_all_tac has moved within claset() from unsafe wrappers to safe
  5584 wrappers, which means that !!-bound variables are split much more
  5585 aggressively, and safe_tac and clarify_tac now split such variables.
  5586 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5587 Note: the same holds for record_split_tac, which does the job of
  5588 split_all_tac for record fields.
  5589 
  5590 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5591 permanently to the default simpset using Addsplits just like
  5592 Addsimps. They can be removed via Delsplits just like
  5593 Delsimps. Lower-case versions are also available.
  5594 
  5595 * HOL/Simplifier: The rule split_if is now part of the default
  5596 simpset. This means that the simplifier will eliminate all occurrences
  5597 of if-then-else in the conclusion of a goal. To prevent this, you can
  5598 either remove split_if completely from the default simpset by
  5599 `Delsplits [split_if]' or remove it in a specific call of the
  5600 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5601 other case splitting rules to/from the default simpset: every datatype
  5602 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5603 t is the name of the datatype).
  5604 
  5605 * Classical reasoner / Simplifier combination: new force_tac (and
  5606 derivatives Force_tac, force) combines rewriting and classical
  5607 reasoning (and whatever other tools) similarly to auto_tac, but is
  5608 aimed to solve the given subgoal completely.
  5609 
  5610 
  5611 *** General ***
  5612 
  5613 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5614 and `goalw': the theory is no longer needed as an explicit argument -
  5615 the current theory context is used; assumptions are no longer returned
  5616 at the ML-level unless one of them starts with ==> or !!; it is
  5617 recommended to convert to these new commands using isatool fixgoal
  5618 (backup your sources first!);
  5619 
  5620 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5621 the current theory context, and 'theory' to lookup stored theories;
  5622 
  5623 * new theory section 'locale' for declaring constants, assumptions and
  5624 definitions that have local scope;
  5625 
  5626 * new theory section 'nonterminals' for purely syntactic types;
  5627 
  5628 * new theory section 'setup' for generic ML setup functions
  5629 (e.g. package initialization);
  5630 
  5631 * the distribution now includes Isabelle icons: see
  5632 lib/logo/isabelle-{small,tiny}.xpm;
  5633 
  5634 * isatool install - install binaries with absolute references to
  5635 ISABELLE_HOME/bin;
  5636 
  5637 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5638 
  5639 * print mode 'emacs' reserved for Isamode;
  5640 
  5641 * support multiple print (ast) translations per constant name;
  5642 
  5643 * theorems involving oracles are now printed with a suffixed [!];
  5644 
  5645 
  5646 *** HOL ***
  5647 
  5648 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5649 
  5650 * HOL/inductive package reorganized and improved: now supports mutual
  5651 definitions such as
  5652 
  5653   inductive EVEN ODD
  5654     intrs
  5655       null "0 : EVEN"
  5656       oddI "n : EVEN ==> Suc n : ODD"
  5657       evenI "n : ODD ==> Suc n : EVEN"
  5658 
  5659 new theorem list "elims" contains an elimination rule for each of the
  5660 recursive sets; inductive definitions now handle disjunctive premises
  5661 correctly (also ZF);
  5662 
  5663 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5664 "mutual_induct" no longer exists - the induction rule is always
  5665 contained in "induct";
  5666 
  5667 
  5668 * HOL/datatype package re-implemented and greatly improved: now
  5669 supports mutually recursive datatypes such as
  5670 
  5671   datatype
  5672     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5673             | SUM ('a aexp) ('a aexp)
  5674             | DIFF ('a aexp) ('a aexp)
  5675             | NUM 'a
  5676   and
  5677     'a bexp = LESS ('a aexp) ('a aexp)
  5678             | AND ('a bexp) ('a bexp)
  5679             | OR ('a bexp) ('a bexp)
  5680 
  5681 as well as indirectly recursive datatypes such as
  5682 
  5683   datatype
  5684     ('a, 'b) term = Var 'a
  5685                   | App 'b ((('a, 'b) term) list)
  5686 
  5687 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5688 induction on mutually / indirectly recursive datatypes.
  5689 
  5690 Primrec equations are now stored in theory and can be accessed via
  5691 <function_name>.simps.
  5692 
  5693 INCOMPATIBILITIES:
  5694 
  5695   - Theories using datatypes must now have theory Datatype as an
  5696     ancestor.
  5697   - The specific <typename>.induct_tac no longer exists - use the
  5698     generic induct_tac instead.
  5699   - natE has been renamed to nat.exhaust - use exhaust_tac
  5700     instead of res_inst_tac ... natE. Note that the variable
  5701     names in nat.exhaust differ from the names in natE, this
  5702     may cause some "fragile" proofs to fail.
  5703   - The theorems split_<typename>_case and split_<typename>_case_asm
  5704     have been renamed to <typename>.split and <typename>.split_asm.
  5705   - Since default sorts of type variables are now handled correctly,
  5706     some datatype definitions may have to be annotated with explicit
  5707     sort constraints.
  5708   - Primrec definitions no longer require function name and type
  5709     of recursive argument.
  5710 
  5711 Consider using isatool fixdatatype to adapt your theories and proof
  5712 scripts to the new package (backup your sources first!).
  5713 
  5714 
  5715 * HOL/record package: considerably improved implementation; now
  5716 includes concrete syntax for record types, terms, updates; theorems
  5717 for surjective pairing and splitting !!-bound record variables; proof
  5718 support is as follows:
  5719 
  5720   1) standard conversions (selectors or updates applied to record
  5721 constructor terms) are part of the standard simpset;
  5722 
  5723   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5724 made part of standard simpset and claset via addIffs;
  5725 
  5726   3) a tactic for record field splitting (record_split_tac) is part of
  5727 the standard claset (addSWrapper);
  5728 
  5729 To get a better idea about these rules you may retrieve them via
  5730 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5731 the name of your record type.
  5732 
  5733 The split tactic 3) conceptually simplifies by the following rule:
  5734 
  5735   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5736 
  5737 Thus any record variable that is bound by meta-all will automatically
  5738 blow up into some record constructor term, consequently the
  5739 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5740 solve record problems automatically.
  5741 
  5742 
  5743 * reorganized the main HOL image: HOL/Integ and String loaded by
  5744 default; theory Main includes everything;
  5745 
  5746 * automatic simplification of integer sums and comparisons, using cancellation;
  5747 
  5748 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5749 
  5750 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5751 
  5752 * many new identities for unions, intersections, set difference, etc.;
  5753 
  5754 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5755 called split_if, split_split, split_sum_case and split_nat_case (to go
  5756 with add/delsplits);
  5757 
  5758 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5759 (?x::unit) = (); this is made part of the default simpset, which COULD
  5760 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5761 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5762 unit_abs_eta_conv is added in order to counter the effect of
  5763 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5764 %u.f();
  5765 
  5766 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5767 makes more sense);
  5768 
  5769 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5770   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5771   disjointness reasoning but breaking a few old proofs.
  5772 
  5773 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5774 to 'converse' from 'inverse' (for compatibility with ZF and some
  5775 literature);
  5776 
  5777 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5778 the well-founded relation;
  5779 
  5780 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5781     Compl A.  The "Compl" syntax remains available as input syntax for this
  5782     release ONLY.
  5783 
  5784 * HOL/Update: new theory of function updates:
  5785     f(a:=b) == %x. if x=a then b else f x
  5786 may also be iterated as in f(a:=b,c:=d,...);
  5787 
  5788 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5789 
  5790 * HOL/List:
  5791   - new function list_update written xs[i:=v] that updates the i-th
  5792     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5793   - new function `upt' written [i..j(] which generates the list
  5794     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5795     bound write [i..j], which is a shorthand for [i..j+1(].
  5796   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5797 
  5798 * HOL/Arith:
  5799   - removed 'pred' (predecessor) function;
  5800   - generalized some theorems about n-1;
  5801   - many new laws about "div" and "mod";
  5802   - new laws about greatest common divisors (see theory ex/Primes);
  5803 
  5804 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5805 instead of "inverse";
  5806 
  5807 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5808   of the multiset ordering;
  5809 
  5810 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5811   (not included by default);
  5812 
  5813 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5814 
  5815 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5816   programs, i.e. different program variables may have different types.
  5817 
  5818 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5819   [previously, this check worked only if the rewrite rule was unconditional]
  5820   Now rew can involve either definitions or equalities (either == or =).
  5821 
  5822 
  5823 *** ZF ***
  5824 
  5825 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5826   only the theorems proved on ZF.ML;
  5827 
  5828 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5829   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5830   disjointness reasoning but breaking a few old proofs.
  5831 
  5832 * ZF/Update: new theory of function updates
  5833     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5834   may also be iterated as in f(a:=b,c:=d,...);
  5835 
  5836 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5837 
  5838 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5839   [previously, this check worked only if the rewrite rule was unconditional]
  5840   Now rew can involve either definitions or equalities (either == or =).
  5841 
  5842 * case_tac provided for compatibility with HOL
  5843     (like the old excluded_middle_tac, but with subgoals swapped)
  5844 
  5845 
  5846 *** Internal programming interfaces ***
  5847 
  5848 * Pure: several new basic modules made available for general use, see
  5849 also src/Pure/README;
  5850 
  5851 * improved the theory data mechanism to support encapsulation (data
  5852 kind name replaced by private Object.kind, acting as authorization
  5853 key); new type-safe user interface via functor TheoryDataFun; generic
  5854 print_data function becomes basically useless;
  5855 
  5856 * removed global_names compatibility flag -- all theory declarations
  5857 are qualified by default;
  5858 
  5859 * module Pure/Syntax now offers quote / antiquote translation
  5860 functions (useful for Hoare logic etc. with implicit dependencies);
  5861 see HOL/ex/Antiquote for an example use;
  5862 
  5863 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5864 cterm -> thm;
  5865 
  5866 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5867 subgoal;
  5868 
  5869 * Display.print_goals function moved to Locale.print_goals;
  5870 
  5871 * standard print function for goals supports current_goals_markers
  5872 variable for marking begin of proof, end of proof, start of goal; the
  5873 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5874 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5875 for example;
  5876 
  5877 
  5878 
  5879 New in Isabelle98 (January 1998)
  5880 --------------------------------
  5881 
  5882 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5883 
  5884 * changed lexical syntax of terms / types: dots made part of long
  5885 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5886 
  5887 * simpset (and claset) reference variable replaced by functions
  5888 simpset / simpset_ref;
  5889 
  5890 * no longer supports theory aliases (via merge) and non-trivial
  5891 implicit merge of thms' signatures;
  5892 
  5893 * most internal names of constants changed due to qualified names;
  5894 
  5895 * changed Pure/Sequence interface (see Pure/seq.ML);
  5896 
  5897 
  5898 *** General Changes ***
  5899 
  5900 * hierachically structured name spaces (for consts, types, axms, thms
  5901 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  5902 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  5903 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  5904 long_names for fully qualified output names; NOTE: ML programs
  5905 (special tactics, packages etc.) referring to internal names may have
  5906 to be adapted to cope with fully qualified names; in case of severe
  5907 backward campatibility problems try setting 'global_names' at compile
  5908 time to have enrything declared within a flat name space; one may also
  5909 fine tune name declarations in theories via the 'global' and 'local'
  5910 section;
  5911 
  5912 * reimplemented the implicit simpset and claset using the new anytype
  5913 data filed in signatures; references simpset:simpset ref etc. are
  5914 replaced by functions simpset:unit->simpset and
  5915 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  5916 to patch your ML files accordingly;
  5917 
  5918 * HTML output now includes theory graph data for display with Java
  5919 applet or isatool browser; data generated automatically via isatool
  5920 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  5921 
  5922 * defs may now be conditional; improved rewrite_goals_tac to handle
  5923 conditional equations;
  5924 
  5925 * defs now admits additional type arguments, using TYPE('a) syntax;
  5926 
  5927 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  5928 creates a new theory node; implicit merge of thms' signatures is
  5929 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  5930 transfer:theory->thm->thm in (rare) cases;
  5931 
  5932 * improved handling of draft signatures / theories; draft thms (and
  5933 ctyps, cterms) are automatically promoted to real ones;
  5934 
  5935 * slightly changed interfaces for oracles: admit many per theory, named
  5936 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  5937 
  5938 * print_goals: optional output of const types (set show_consts and
  5939 show_types);
  5940 
  5941 * improved output of warnings (###) and errors (***);
  5942 
  5943 * subgoal_tac displays a warning if the new subgoal has type variables;
  5944 
  5945 * removed old README and Makefiles;
  5946 
  5947 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  5948 
  5949 * removed obsolete init_pps and init_database;
  5950 
  5951 * deleted the obsolete tactical STATE, which was declared by
  5952     fun STATE tacfun st = tacfun st st;
  5953 
  5954 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  5955 (which abbreviates $HOME);
  5956 
  5957 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  5958 use isatool fixseq to adapt your ML programs (this works for fully
  5959 qualified references to the Sequence structure only!);
  5960 
  5961 * use_thy no longer requires writable current directory; it always
  5962 reloads .ML *and* .thy file, if either one is out of date;
  5963 
  5964 
  5965 *** Classical Reasoner ***
  5966 
  5967 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  5968 tactics that use classical reasoning to simplify a subgoal without
  5969 splitting it into several subgoals;
  5970 
  5971 * Safe_tac: like safe_tac but uses the default claset;
  5972 
  5973 
  5974 *** Simplifier ***
  5975 
  5976 * added simplification meta rules:
  5977     (asm_)(full_)simplify: simpset -> thm -> thm;
  5978 
  5979 * simplifier.ML no longer part of Pure -- has to be loaded by object
  5980 logics (again);
  5981 
  5982 * added prems argument to simplification procedures;
  5983 
  5984 * HOL, FOL, ZF: added infix function `addsplits':
  5985   instead of `<simpset> setloop (split_tac <thms>)'
  5986   you can simply write `<simpset> addsplits <thms>'
  5987 
  5988 
  5989 *** Syntax ***
  5990 
  5991 * TYPE('a) syntax for type reflection terms;
  5992 
  5993 * no longer handles consts with name "" -- declare as 'syntax' instead;
  5994 
  5995 * pretty printer: changed order of mixfix annotation preference (again!);
  5996 
  5997 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  5998 
  5999 
  6000 *** HOL ***
  6001 
  6002 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6003   with `addloop' of the simplifier to faciliate case splitting in premises.
  6004 
  6005 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6006 
  6007 * HOL/Auth: new protocol proofs including some for the Internet
  6008   protocol TLS;
  6009 
  6010 * HOL/Map: new theory of `maps' a la VDM;
  6011 
  6012 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6013 cancelling out common nat summands from =, <, <= (in)equalities, or
  6014 differences; simplification procedures nat_cancel_factor for
  6015 cancelling common factor from =, <, <= (in)equalities over natural
  6016 sums; nat_cancel contains both kinds of procedures, it is installed by
  6017 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6018 
  6019 * HOL/simplifier: terms of the form
  6020   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6021   are rewritten to
  6022   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6023   and those of the form
  6024   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6025   are rewritten to
  6026   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6027 
  6028 * HOL/datatype
  6029   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6030 
  6031   P(t_case f1 ... fn x) =
  6032      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6033         ...
  6034        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6035      )
  6036 
  6037   and a theorem `split_t_case_asm' of the form
  6038 
  6039   P(t_case f1 ... fn x) =
  6040     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6041         ...
  6042        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6043      )
  6044   which can be added to a simpset via `addsplits'. The existing theorems
  6045   expand_list_case and expand_option_case have been renamed to
  6046   split_list_case and split_option_case.
  6047 
  6048 * HOL/Arithmetic:
  6049   - `pred n' is automatically converted to `n-1'.
  6050     Users are strongly encouraged not to use `pred' any longer,
  6051     because it will disappear altogether at some point.
  6052   - Users are strongly encouraged to write "0 < n" rather than
  6053     "n ~= 0". Theorems and proof tools have been modified towards this
  6054     `standard'.
  6055 
  6056 * HOL/Lists:
  6057   the function "set_of_list" has been renamed "set" (and its theorems too);
  6058   the function "nth" now takes its arguments in the reverse order and
  6059   has acquired the infix notation "!" as in "xs!n".
  6060 
  6061 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6062 
  6063 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6064   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6065 
  6066 * HOL/record: extensible records with schematic structural subtyping
  6067 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6068 still lacks various theorems and concrete record syntax;
  6069 
  6070 
  6071 *** HOLCF ***
  6072 
  6073 * removed "axioms" and "generated by" sections;
  6074 
  6075 * replaced "ops" section by extended "consts" section, which is capable of
  6076   handling the continuous function space "->" directly;
  6077 
  6078 * domain package:
  6079   . proves theorems immediately and stores them in the theory,
  6080   . creates hierachical name space,
  6081   . now uses normal mixfix annotations (instead of cinfix...),
  6082   . minor changes to some names and values (for consistency),
  6083   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6084   . separator between mutual domain defs: changed "," to "and",
  6085   . improved handling of sort constraints;  now they have to
  6086     appear on the left-hand side of the equations only;
  6087 
  6088 * fixed LAM <x,y,zs>.b syntax;
  6089 
  6090 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6091 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6092 
  6093 
  6094 *** FOL and ZF ***
  6095 
  6096 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6097   with `addloop' of the simplifier to faciliate case splitting in premises.
  6098 
  6099 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6100 in HOL, they strip ALL and --> from proved theorems;
  6101 
  6102 
  6103 
  6104 New in Isabelle94-8 (May 1997)
  6105 ------------------------------
  6106 
  6107 *** General Changes ***
  6108 
  6109 * new utilities to build / run / maintain Isabelle etc. (in parts
  6110 still somewhat experimental); old Makefiles etc. still functional;
  6111 
  6112 * new 'Isabelle System Manual';
  6113 
  6114 * INSTALL text, together with ./configure and ./build scripts;
  6115 
  6116 * reimplemented type inference for greater efficiency, better error
  6117 messages and clean internal interface;
  6118 
  6119 * prlim command for dealing with lots of subgoals (an easier way of
  6120 setting goals_limit);
  6121 
  6122 
  6123 *** Syntax ***
  6124 
  6125 * supports alternative (named) syntax tables (parser and pretty
  6126 printer); internal interface is provided by add_modesyntax(_i);
  6127 
  6128 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6129 be used in conjunction with the Isabelle symbol font; uses the
  6130 "symbols" syntax table;
  6131 
  6132 * added token_translation interface (may translate name tokens in
  6133 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6134 the current print_mode); IMPORTANT: user print translation functions
  6135 are responsible for marking newly introduced bounds
  6136 (Syntax.mark_boundT);
  6137 
  6138 * token translations for modes "xterm" and "xterm_color" that display
  6139 names in bold, underline etc. or colors (which requires a color
  6140 version of xterm);
  6141 
  6142 * infixes may now be declared with names independent of their syntax;
  6143 
  6144 * added typed_print_translation (like print_translation, but may
  6145 access type of constant);
  6146 
  6147 
  6148 *** Classical Reasoner ***
  6149 
  6150 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  6151 some limitations.  Blast_tac...
  6152   + ignores addss, addbefore, addafter; this restriction is intrinsic
  6153   + ignores elimination rules that don't have the correct format
  6154         (the conclusion MUST be a formula variable)
  6155   + ignores types, which can make HOL proofs fail
  6156   + rules must not require higher-order unification, e.g. apply_type in ZF
  6157     [message "Function Var's argument not a bound variable" relates to this]
  6158   + its proof strategy is more general but can actually be slower
  6159 
  6160 * substitution with equality assumptions no longer permutes other
  6161 assumptions;
  6162 
  6163 * minor changes in semantics of addafter (now called addaltern); renamed
  6164 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  6165 (and access functions for it);
  6166 
  6167 * improved combination of classical reasoner and simplifier:
  6168   + functions for handling clasimpsets
  6169   + improvement of addss: now the simplifier is called _after_ the
  6170     safe steps.
  6171   + safe variant of addss called addSss: uses safe simplifications
  6172     _during_ the safe steps. It is more complete as it allows multiple
  6173     instantiations of unknowns (e.g. with slow_tac).
  6174 
  6175 *** Simplifier ***
  6176 
  6177 * added interface for simplification procedures (functions that
  6178 produce *proven* rewrite rules on the fly, depending on current
  6179 redex);
  6180 
  6181 * ordering on terms as parameter (used for ordered rewriting);
  6182 
  6183 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  6184 
  6185 * the solver is now split into a safe and an unsafe part.
  6186 This should be invisible for the normal user, except that the
  6187 functions setsolver and addsolver have been renamed to setSolver and
  6188 addSolver; added safe_asm_full_simp_tac;
  6189 
  6190 
  6191 *** HOL ***
  6192 
  6193 * a generic induction tactic `induct_tac' which works for all datatypes and
  6194 also for type `nat';
  6195 
  6196 * a generic case distinction tactic `exhaust_tac' which works for all
  6197 datatypes and also for type `nat';
  6198 
  6199 * each datatype comes with a function `size';
  6200 
  6201 * patterns in case expressions allow tuple patterns as arguments to
  6202 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  6203 
  6204 * primrec now also works with type nat;
  6205 
  6206 * recdef: a new declaration form, allows general recursive functions to be
  6207 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  6208 
  6209 * the constant for negation has been renamed from "not" to "Not" to
  6210 harmonize with FOL, ZF, LK, etc.;
  6211 
  6212 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  6213 infinite lists;
  6214 
  6215 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  6216 
  6217 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  6218 problems in commutative rings, using axiomatic type classes for + and *;
  6219 
  6220 * more examples in HOL/MiniML and HOL/Auth;
  6221 
  6222 * more default rewrite rules for quantifiers, union/intersection;
  6223 
  6224 * a new constant `arbitrary == @x.False';
  6225 
  6226 * HOLCF/IOA replaces old HOL/IOA;
  6227 
  6228 * HOLCF changes: derived all rules and arities
  6229   + axiomatic type classes instead of classes
  6230   + typedef instead of faking type definitions
  6231   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  6232   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  6233   + eliminated the types void, one, tr
  6234   + use unit lift and bool lift (with translations) instead of one and tr
  6235   + eliminated blift from Lift3.thy (use Def instead of blift)
  6236   all eliminated rules are derived as theorems --> no visible changes ;
  6237 
  6238 
  6239 *** ZF ***
  6240 
  6241 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  6242 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  6243 as ZF_cs addSIs [equalityI];
  6244 
  6245 
  6246 
  6247 New in Isabelle94-7 (November 96)
  6248 ---------------------------------
  6249 
  6250 * allowing negative levels (as offsets) in prlev and choplev;
  6251 
  6252 * super-linear speedup for large simplifications;
  6253 
  6254 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  6255 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  6256 FAIL); can suppress it using the command Delsimps (ex_simps @
  6257 all_simps); De Morgan laws are also now included, by default;
  6258 
  6259 *