NEWS
author haftmann
Mon Sep 21 15:35:14 2009 +0200 (2009-09-21)
changeset 32691 cdf70f1fc9f9
parent 32686 a62c8627931b
child 32697 72e8608dce54
permissions -rw-r--r--
added note on simp rules
     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 * New proof method "smt" for a combination of first-order logic
    22 with equality, linear and nonlinear (natural/integer/real)
    23 arithmetic, and fixed-size bitvectors; there is also basic
    24 support for higher-order features (esp. lambda abstractions).
    25 It is an incomplete decision procedure based on external SMT
    26 solvers using the oracle mechanism.
    27 
    28 * Reorganization of number theory:
    29   * former session NumberTheory now named Old_Number_Theory
    30   * new session Number_Theory by Jeremy Avigad; if possible, prefer this.
    31   * moved legacy theories Legacy_GCD and Primes from Library/ to Old_Number_Theory/;
    32   * moved theory Pocklington from Library/ to Old_Number_Theory/;
    33   * removed various references to Old_Number_Theory from HOL distribution.
    34 INCOMPATIBILITY.
    35 
    36 * Theory GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm
    37 of finite and infinite sets. It is shown that they form a complete
    38 lattice.
    39 
    40 * Split off prime number ingredients from theory GCD
    41 to theory Number_Theory/Primes;
    42 
    43 * Class semiring_div requires superclass no_zero_divisors and proof of
    44 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    45 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    46 generalized to class semiring_div, subsuming former theorems
    47 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    48 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    49 INCOMPATIBILITY.
    50 
    51 * New testing tool "Mirabelle" for automated (proof) tools. Applies
    52 several tools and tactics like sledgehammer, metis, or quickcheck, to
    53 every proof step in a theory. To be used in batch mode via the
    54 "mirabelle" utility.
    55 
    56 * New proof method "sos" (sum of squares) for nonlinear real
    57 arithmetic (originally due to John Harison). It requires
    58 Library/Sum_Of_Squares.  It is not a complete decision procedure but
    59 works well in practice on quantifier-free real arithmetic with +, -,
    60 *, ^, =, <= and <, i.e. boolean combinations of equalities and
    61 inequalities between polynomials. It makes use of external
    62 semidefinite programming solvers.  For more information and examples
    63 see src/HOL/Library/Sum_Of_Squares.
    64 
    65 * Code generator attributes follow the usual underscore convention:
    66     code_unfold     replaces    code unfold
    67     code_post       replaces    code post
    68     etc.
    69   INCOMPATIBILITY.
    70 
    71 * Refinements to lattice classes and sets:
    72   - less default intro/elim rules in locale variant, more default
    73     intro/elim rules in class variant: more uniformity
    74   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    75   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    76   - renamed ACI to inf_sup_aci
    77   - new class "boolean_algebra"
    78   - class "complete_lattice" moved to separate theory "complete_lattice";
    79     corresponding constants (and abbreviations) renamed and with authentic syntax:
    80     Set.Inf ~>      Complete_Lattice.Inf
    81     Set.Sup ~>      Complete_Lattice.Sup
    82     Set.INFI ~>     Complete_Lattice.INFI
    83     Set.SUPR ~>     Complete_Lattice.SUPR
    84     Set.Inter ~>    Complete_Lattice.Inter
    85     Set.Union ~>    Complete_Lattice.Union
    86     Set.INTER ~>    Complete_Lattice.INTER
    87     Set.UNION ~>    Complete_Lattice.UNION
    88   - more convenient names for set intersection and union:
    89     Set.Int ~>      Set.inter
    90     Set.Un ~>       Set.union
    91   - authentic syntax for
    92     Set.Pow
    93     Set.image
    94   - mere abbreviations:
    95     Set.empty               (for bot)
    96     Set.UNIV                (for top)
    97     Set.inter               (for inf)
    98     Set.union               (for sup)
    99     Complete_Lattice.Inter  (for Inf)
   100     Complete_Lattice.Union  (for Sup)
   101     Complete_Lattice.INTER  (for INFI)
   102     Complete_Lattice.UNION  (for SUPR)
   103   - object-logic definitions as far as appropriate
   104 
   105 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   106 Un_subset_iff are explicitly deleted as default simp rules;  then
   107 also their lattice counterparts le_inf_iff and le_sup_iff have to be
   108 deleted to achieve the desired effect.
   109 
   110 * Power operations on relations and functions are now one dedicate
   111 constant "compow" with infix syntax "^^".  Power operations on
   112 multiplicative monoids retains syntax "^" and is now defined generic
   113 in class power.  INCOMPATIBILITY.
   114 
   115 * Relation composition "R O S" now has a "more standard" argument
   116 order, i.e., "R O S = {(x,z). EX y. (x,y) : R & (y,z) : S }".
   117 INCOMPATIBILITY: Rewrite propositions with "S O R" --> "R O S". Proofs
   118 may occationally break, since the O_assoc rule was not rewritten like
   119 this.  Fix using O_assoc[symmetric].  The same applies to the curried
   120 version "R OO S".
   121 
   122 * ML antiquotation @{code_datatype} inserts definition of a datatype
   123 generated by the code generator; see Predicate.thy for an example.
   124 
   125 * New method "linarith" invokes existing linear arithmetic decision
   126 procedure only.
   127 
   128 * New implementation of quickcheck uses generic code generator;
   129 default generators are provided for all suitable HOL types, records
   130 and datatypes.
   131 
   132 * Renamed theorems:
   133 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   134 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   135 Suc_plus1 -> Suc_eq_plus1
   136 
   137 * Moved theorems:
   138 Wellfounded.in_inv_image -> Relation.in_inv_image
   139 
   140 * New sledgehammer option "Full Types" in Proof General settings menu.
   141 Causes full type information to be output to the ATPs.  This slows
   142 ATPs down considerably but eliminates a source of unsound "proofs"
   143 that fail later.
   144 
   145 * New method metisFT: A version of metis that uses full type information
   146 in order to avoid failures of proof reconstruction.
   147 
   148 * Discontinued ancient tradition to suffix certain ML module names
   149 with "_package", e.g.:
   150 
   151     DatatypePackage ~> Datatype
   152     InductivePackage ~> Inductive
   153 
   154 INCOMPATIBILITY.
   155 
   156 * Discontinued abbreviation "arbitrary" of constant
   157 "undefined". INCOMPATIBILITY, use "undefined" directly.
   158 
   159 * New evaluator "approximate" approximates an real valued term using
   160 the same method as the approximation method.
   161 
   162 * Method "approximate" supports now arithmetic expressions as
   163 boundaries of intervals and implements interval splitting and Taylor
   164 series expansion.
   165 
   166 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   167 the theorems in DERIV_intros assumes composition with an additional
   168 function and matches a variable to the derivative, which has to be
   169 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   170 the derivative of most elementary terms.
   171 
   172 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   173 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   174 
   175 
   176 *** ML ***
   177 
   178 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   179 parallel tactical reasoning.
   180 
   181 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   182 are similar to SUBPROOF, but are slightly more flexible: only the
   183 specified parts of the subgoal are imported into the context, and the
   184 body tactic may introduce new subgoals and schematic variables.
   185 
   186 * Old tactical METAHYPS, which does not observe the proof context, has
   187 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   188 or Subgoal.FOCUS etc.
   189 
   190 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   191 functors have their own ML name space there is no point to mark them
   192 separately.)  Minor INCOMPATIBILITY.
   193 
   194 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   195 
   196 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   197 cominators for "args".  INCOMPATIBILITY, need to use simplified
   198 Attrib/Method.setup introduced in Isabelle2009.
   199 
   200 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   201 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   202 last resort.  INCOMPATIBILITY.
   203 
   204 * Display.pretty_thm now requires a proper context (cf. former
   205 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   206 or even Display.pretty_thm_without_context as last resort.
   207 INCOMPATIBILITY.
   208 
   209 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   210 Syntax.pretty_typ/term directly, preferably with proper context
   211 instead of global theory.
   212 
   213 
   214 *** System ***
   215 
   216 * Support for additional "Isabelle components" via etc/components, see
   217 also the system manual.
   218 
   219 * The isabelle makeall tool now operates on all components with
   220 IsaMakefile, not just hardwired "logics".
   221 
   222 * Discontinued support for Poly/ML 4.x versions.
   223 
   224 * Removed "compress" option from isabelle-process and isabelle usedir;
   225 this is always enabled.
   226 
   227 * More fine-grained control of proof parallelism, cf.
   228 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   229 
   230 
   231 
   232 New in Isabelle2009 (April 2009)
   233 --------------------------------
   234 
   235 *** General ***
   236 
   237 * Simplified main Isabelle executables, with less surprises on
   238 case-insensitive file-systems (such as Mac OS).
   239 
   240   - The main Isabelle tool wrapper is now called "isabelle" instead of
   241     "isatool."
   242 
   243   - The former "isabelle" alias for "isabelle-process" has been
   244     removed (should rarely occur to regular users).
   245 
   246   - The former "isabelle-interface" and its alias "Isabelle" have been
   247     removed (interfaces are now regular Isabelle tools).
   248 
   249 Within scripts and make files, the Isabelle environment variables
   250 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   251 respectively.  (The latter are still available as legacy feature.)
   252 
   253 The old isabelle-interface wrapper could react in confusing ways if
   254 the interface was uninstalled or changed otherwise.  Individual
   255 interface tool configuration is now more explicit, see also the
   256 Isabelle system manual.  In particular, Proof General is now available
   257 via "isabelle emacs".
   258 
   259 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   260 purge installed copies of Isabelle executables and re-run "isabelle
   261 install -p ...", or use symlinks.
   262 
   263 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   264 old ~/isabelle, which was slightly non-standard and apt to cause
   265 surprises on case-insensitive file-systems (such as Mac OS).
   266 
   267 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   268 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   269 care is required when using older releases of Isabelle.  Note that
   270 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   271 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   272 
   273 * Proofs of fully specified statements are run in parallel on
   274 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   275 a regular 4-core machine, if the initial heap space is made reasonably
   276 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   277 
   278 * The main reference manuals ("isar-ref", "implementation", and
   279 "system") have been updated and extended.  Formally checked references
   280 as hyperlinks are now available uniformly.
   281 
   282 
   283 *** Pure ***
   284 
   285 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   286 respects.  The most important changes are listed below.  See the
   287 Tutorial on Locales ("locales" manual) for details.
   288 
   289 - In locale expressions, instantiation replaces renaming.  Parameters
   290 must be declared in a for clause.  To aid compatibility with previous
   291 parameter inheritance, in locale declarations, parameters that are not
   292 'touched' (instantiation position "_" or omitted) are implicitly added
   293 with their syntax at the beginning of the for clause.
   294 
   295 - Syntax from abbreviations and definitions in locales is available in
   296 locale expressions and context elements.  The latter is particularly
   297 useful in locale declarations.
   298 
   299 - More flexible mechanisms to qualify names generated by locale
   300 expressions.  Qualifiers (prefixes) may be specified in locale
   301 expressions, and can be marked as mandatory (syntax: "name!:") or
   302 optional (syntax "name?:").  The default depends for plain "name:"
   303 depends on the situation where a locale expression is used: in
   304 commands 'locale' and 'sublocale' prefixes are optional, in
   305 'interpretation' and 'interpret' prefixes are mandatory.  The old
   306 implicit qualifiers derived from the parameter names of a locale are
   307 no longer generated.
   308 
   309 - Command "sublocale l < e" replaces "interpretation l < e".  The
   310 instantiation clause in "interpretation" and "interpret" (square
   311 brackets) is no longer available.  Use locale expressions.
   312 
   313 - When converting proof scripts, mandatory qualifiers in
   314 'interpretation' and 'interpret' should be retained by default, even
   315 if this is an INCOMPATIBILITY compared to former behavior.  In the
   316 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   317 in locale expressions range over a single locale instance only.
   318 
   319 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   320 In existing theorem specifications replace the includes element by the
   321 respective context elements of the included locale, omitting those
   322 that are already present in the theorem specification.  Multiple
   323 assume elements of a locale should be replaced by a single one
   324 involving the locale predicate.  In the proof body, declarations (most
   325 notably theorems) may be regained by interpreting the respective
   326 locales in the proof context as required (command "interpret").
   327 
   328 If using "includes" in replacement of a target solely because the
   329 parameter types in the theorem are not as general as in the target,
   330 consider declaring a new locale with additional type constraints on
   331 the parameters (context element "constrains").
   332 
   333 - Discontinued "locale (open)".  INCOMPATIBILITY.
   334 
   335 - Locale interpretation commands no longer attempt to simplify goal.
   336 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   337 methods intro_locales and unfold_locales to clarify.
   338 
   339 - Locale interpretation commands no longer accept interpretation
   340 attributes.  INCOMPATIBILITY.
   341 
   342 * Class declaration: so-called "base sort" must not be given in import
   343 list any longer, but is inferred from the specification.  Particularly
   344 in HOL, write
   345 
   346     class foo = ...
   347 
   348 instead of
   349 
   350     class foo = type + ...
   351 
   352 * Class target: global versions of theorems stemming do not carry a
   353 parameter prefix any longer.  INCOMPATIBILITY.
   354 
   355 * Class 'instance' command no longer accepts attached definitions.
   356 INCOMPATIBILITY, use proper 'instantiation' target instead.
   357 
   358 * Recovered hiding of consts, which was accidentally broken in
   359 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   360 makes c inaccessible; consider using ``hide (open) const c'' instead.
   361 
   362 * Slightly more coherent Pure syntax, with updated documentation in
   363 isar-ref manual.  Removed locales meta_term_syntax and
   364 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   365 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   366 directly in regular applications.
   367 
   368 * There is a new syntactic category "float_const" for signed decimal
   369 fractions (e.g. 123.45 or -123.45).
   370 
   371 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   372 interface with 'setup' command instead.
   373 
   374 * Command 'local_setup' is similar to 'setup', but operates on a local
   375 theory context.
   376 
   377 * The 'axiomatization' command now only works within a global theory
   378 context.  INCOMPATIBILITY.
   379 
   380 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   381 hypotheses.  Sorts required in the course of reasoning need to be
   382 covered by the constraints in the initial statement, completed by the
   383 type instance information of the background theory.  Non-trivial sort
   384 hypotheses, which rarely occur in practice, may be specified via
   385 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   386 
   387   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   388 
   389 The result contains an implicit sort hypotheses as before --
   390 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   391 normalization.
   392 
   393 * Generalized Isar history, with support for linear undo, direct state
   394 addressing etc.
   395 
   396 * Changed defaults for unify configuration options:
   397 
   398   unify_trace_bound = 50 (formerly 25)
   399   unify_search_bound = 60 (formerly 30)
   400 
   401 * Different bookkeeping for code equations (INCOMPATIBILITY):
   402 
   403   a) On theory merge, the last set of code equations for a particular
   404      constant is taken (in accordance with the policy applied by other
   405      parts of the code generator framework).
   406 
   407   b) Code equations stemming from explicit declarations (e.g. code
   408      attribute) gain priority over default code equations stemming
   409      from definition, primrec, fun etc.
   410 
   411 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   412 
   413 * Unified theorem tables for both code generators.  Thus [code
   414 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   415 
   416 * Command 'find_consts' searches for constants based on type and name
   417 patterns, e.g.
   418 
   419     find_consts "_ => bool"
   420 
   421 By default, matching is against subtypes, but it may be restricted to
   422 the whole type.  Searching by name is possible.  Multiple queries are
   423 conjunctive and queries may be negated by prefixing them with a
   424 hyphen:
   425 
   426     find_consts strict: "_ => bool" name: "Int" -"int => int"
   427 
   428 * New 'find_theorems' criterion "solves" matches theorems that
   429 directly solve the current goal (modulo higher-order unification).
   430 
   431 * Auto solve feature for main theorem statements: whenever a new goal
   432 is stated, "find_theorems solves" is called; any theorems that could
   433 solve the lemma directly are listed as part of the goal state.
   434 Cf. associated options in Proof General Isabelle settings menu,
   435 enabled by default, with reasonable timeout for pathological cases of
   436 higher-order unification.
   437 
   438 
   439 *** Document preparation ***
   440 
   441 * Antiquotation @{lemma} now imitates a regular terminal proof,
   442 demanding keyword 'by' and supporting the full method expression
   443 syntax just like the Isar command 'by'.
   444 
   445 
   446 *** HOL ***
   447 
   448 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   449 points Main and Complex_Main remain as before.
   450 
   451 * Logic image HOL-Plain provides a minimal HOL with the most important
   452 tools available (inductive, datatype, primrec, ...).  This facilitates
   453 experimentation and tool development.  Note that user applications
   454 (and library theories) should never refer to anything below theory
   455 Main, as before.
   456 
   457 * Logic image HOL-Main stops at theory Main, and thus facilitates
   458 experimentation due to shorter build times.
   459 
   460 * Logic image HOL-NSA contains theories of nonstandard analysis which
   461 were previously part of former HOL-Complex.  Entry point Hyperreal
   462 remains valid, but theories formerly using Complex_Main should now use
   463 new entry point Hypercomplex.
   464 
   465 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   466 Posix processes.  Avoids potentially expensive forking of the ML
   467 process.  New thread-based implementation also works on non-Unix
   468 platforms (Cygwin).  Provers are no longer hardwired, but defined
   469 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   470 commands are covered in the isar-ref manual.
   471 
   472 * Wrapper scripts for remote SystemOnTPTP service allows to use
   473 sledgehammer without local ATP installation (Vampire etc.). Other
   474 provers may be included via suitable ML wrappers, see also
   475 src/HOL/ATP_Linkup.thy.
   476 
   477 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   478 menu.
   479 
   480 * The metis method no longer fails because the theorem is too trivial
   481 (contains the empty clause).
   482 
   483 * The metis method now fails in the usual manner, rather than raising
   484 an exception, if it determines that it cannot prove the theorem.
   485 
   486 * Method "coherent" implements a prover for coherent logic (see also
   487 src/Tools/coherent.ML).
   488 
   489 * Constants "undefined" and "default" replace "arbitrary".  Usually
   490 "undefined" is the right choice to replace "arbitrary", though
   491 logically there is no difference.  INCOMPATIBILITY.
   492 
   493 * Command "value" now integrates different evaluation mechanisms.  The
   494 result of the first successful evaluation mechanism is printed.  In
   495 square brackets a particular named evaluation mechanisms may be
   496 specified (currently, [SML], [code] or [nbe]).  See further
   497 src/HOL/ex/Eval_Examples.thy.
   498 
   499 * Normalization by evaluation now allows non-leftlinear equations.
   500 Declare with attribute [code nbe].
   501 
   502 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   503 as the structured Isar versions "cases" and "induct", cf. the
   504 corresponding "cases" and "induct" attributes.  Mutual induction rules
   505 are now presented as a list of individual projections
   506 (e.g. foo_bar.inducts for types foo and bar); the old format with
   507 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   508 rare situations a different rule is selected --- notably nested tuple
   509 elimination instead of former prod.exhaust: use explicit (case_tac t
   510 rule: prod.exhaust) here.
   511 
   512 * Attributes "cases", "induct", "coinduct" support "del" option.
   513 
   514 * Removed fact "case_split_thm", which duplicates "case_split".
   515 
   516 * The option datatype has been moved to a new theory Option.  Renamed
   517 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   518 
   519 * New predicate "strict_mono" classifies strict functions on partial
   520 orders.  With strict functions on linear orders, reasoning about
   521 (in)equalities is facilitated by theorems "strict_mono_eq",
   522 "strict_mono_less_eq" and "strict_mono_less".
   523 
   524 * Some set operations are now proper qualified constants with
   525 authentic syntax.  INCOMPATIBILITY:
   526 
   527     op Int ~>   Set.Int
   528     op Un ~>    Set.Un
   529     INTER ~>    Set.INTER
   530     UNION ~>    Set.UNION
   531     Inter ~>    Set.Inter
   532     Union ~>    Set.Union
   533     {} ~>       Set.empty
   534     UNIV ~>     Set.UNIV
   535 
   536 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   537 theory Set.
   538 
   539 * Auxiliary class "itself" has disappeared -- classes without any
   540 parameter are treated as expected by the 'class' command.
   541 
   542 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   543 
   544 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   545 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   546 
   547 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   548 method "approximation".  It proves formulas on real values by using
   549 interval arithmetic.  In the formulas are also the transcendental
   550 functions sin, cos, tan, atan, ln, exp and the constant pi are
   551 allowed. For examples see
   552 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   553 
   554 * Theory "Reflection" now resides in HOL/Library.
   555 
   556 * Entry point to Word library now simply named "Word".
   557 INCOMPATIBILITY.
   558 
   559 * Made source layout more coherent with logical distribution
   560 structure:
   561 
   562     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   563     src/HOL/Library/Code_Message.thy ~> src/HOL/
   564     src/HOL/Library/GCD.thy ~> src/HOL/
   565     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   566     src/HOL/Library/Parity.thy ~> src/HOL/
   567     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   568     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   569     src/HOL/Real/Lubs.thy ~> src/HOL/
   570     src/HOL/Real/PReal.thy ~> src/HOL/
   571     src/HOL/Real/Rational.thy ~> src/HOL/
   572     src/HOL/Real/RComplete.thy ~> src/HOL/
   573     src/HOL/Real/RealDef.thy ~> src/HOL/
   574     src/HOL/Real/RealPow.thy ~> src/HOL/
   575     src/HOL/Real/Real.thy ~> src/HOL/
   576     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   577     src/HOL/Complex/Complex.thy ~> src/HOL/
   578     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   579     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   580     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   581     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   582     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   583     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   584     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   585     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   586     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   587     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   588     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   589     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   590     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   591     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   592     src/HOL/Real/Float ~> src/HOL/Library/
   593     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   594     src/HOL/Real/RealVector.thy ~> src/HOL/
   595 
   596     src/HOL/arith_data.ML ~> src/HOL/Tools
   597     src/HOL/hologic.ML ~> src/HOL/Tools
   598     src/HOL/simpdata.ML ~> src/HOL/Tools
   599     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   600     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   601     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   602     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   603     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   604     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   605     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   606 
   607     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   608     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   609     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   610     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   611     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   612     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   613 
   614 * If methods "eval" and "evaluation" encounter a structured proof
   615 state with !!/==>, only the conclusion is evaluated to True (if
   616 possible), avoiding strange error messages.
   617 
   618 * Method "sizechange" automates termination proofs using (a
   619 modification of) the size-change principle.  Requires SAT solver.  See
   620 src/HOL/ex/Termination.thy for examples.
   621 
   622 * Simplifier: simproc for let expressions now unfolds if bound
   623 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   624 
   625 * Method "arith": Linear arithmetic now ignores all inequalities when
   626 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   627 
   628 * New attribute "arith" for facts that should always be used
   629 automatically by arithmetic. It is intended to be used locally in
   630 proofs, e.g.
   631 
   632   assumes [arith]: "x > 0"
   633 
   634 Global usage is discouraged because of possible performance impact.
   635 
   636 * New classes "top" and "bot" with corresponding operations "top" and
   637 "bot" in theory Orderings; instantiation of class "complete_lattice"
   638 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   639 
   640 * Changed definition lemma "less_fun_def" in order to provide an
   641 instance for preorders on functions; use lemma "less_le" instead.
   642 INCOMPATIBILITY.
   643 
   644 * Theory Orderings: class "wellorder" moved here, with explicit
   645 induction rule "less_induct" as assumption.  For instantiation of
   646 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   647 INCOMPATIBILITY.
   648 
   649 * Theory Orderings: added class "preorder" as superclass of "order".
   650 INCOMPATIBILITY: Instantiation proofs for order, linorder
   651 etc. slightly changed.  Some theorems named order_class.* now named
   652 preorder_class.*.
   653 
   654 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   655 "diag" to "Id_on".
   656 
   657 * Theory Finite_Set: added a new fold combinator of type
   658 
   659   ('a => 'b => 'b) => 'b => 'a set => 'b
   660 
   661 Occasionally this is more convenient than the old fold combinator
   662 which is now defined in terms of the new one and renamed to
   663 fold_image.
   664 
   665 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   666 and "ring_simps" have been replaced by "algebra_simps" (which can be
   667 extended with further lemmas!).  At the moment both still exist but
   668 the former will disappear at some point.
   669 
   670 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   671 class recpower.  Type-specific simp rules for various recpower types
   672 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   673 
   674 rat_power_0    -> power_0
   675 rat_power_Suc  -> power_Suc
   676 realpow_0      -> power_0
   677 realpow_Suc    -> power_Suc
   678 complexpow_0   -> power_0
   679 complexpow_Suc -> power_Suc
   680 power_poly_0   -> power_0
   681 power_poly_Suc -> power_Suc
   682 
   683 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   684 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   685 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   686 of lemmas from Divides has been generalized from nat to class
   687 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   688 renames resulting from duplicate elimination:
   689 
   690     dvd_def_mod ~>          dvd_eq_mod_eq_0
   691     zero_dvd_iff ~>         dvd_0_left_iff
   692     dvd_0 ~>                dvd_0_right
   693     DIVISION_BY_ZERO_DIV ~> div_by_0
   694     DIVISION_BY_ZERO_MOD ~> mod_by_0
   695     mult_div ~>             div_mult_self2_is_id
   696     mult_mod ~>             mod_mult_self2_is_0
   697 
   698 * Theory IntDiv: removed many lemmas that are instances of class-based
   699 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   700 rename old lemmas as follows:
   701 
   702 dvd_diff               -> nat_dvd_diff
   703 dvd_zminus_iff         -> dvd_minus_iff
   704 mod_add1_eq            -> mod_add_eq
   705 mod_mult1_eq           -> mod_mult_right_eq
   706 mod_mult1_eq'          -> mod_mult_left_eq
   707 mod_mult_distrib_mod   -> mod_mult_eq
   708 nat_mod_add_left_eq    -> mod_add_left_eq
   709 nat_mod_add_right_eq   -> mod_add_right_eq
   710 nat_mod_div_trivial    -> mod_div_trivial
   711 nat_mod_mod_trivial    -> mod_mod_trivial
   712 zdiv_zadd_self1        -> div_add_self1
   713 zdiv_zadd_self2        -> div_add_self2
   714 zdiv_zmult_self1       -> div_mult_self2_is_id
   715 zdiv_zmult_self2       -> div_mult_self1_is_id
   716 zdvd_triv_left         -> dvd_triv_left
   717 zdvd_triv_right        -> dvd_triv_right
   718 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   719 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   720 zmod_zadd_left_eq      -> mod_add_left_eq
   721 zmod_zadd_right_eq     -> mod_add_right_eq
   722 zmod_zadd_self1        -> mod_add_self1
   723 zmod_zadd_self2        -> mod_add_self2
   724 zmod_zadd1_eq          -> mod_add_eq
   725 zmod_zdiff1_eq         -> mod_diff_eq
   726 zmod_zdvd_zmod         -> mod_mod_cancel
   727 zmod_zmod_cancel       -> mod_mod_cancel
   728 zmod_zmult_self1       -> mod_mult_self2_is_0
   729 zmod_zmult_self2       -> mod_mult_self1_is_0
   730 zmod_1                 -> mod_by_1
   731 zdiv_1                 -> div_by_1
   732 zdvd_abs1              -> abs_dvd_iff
   733 zdvd_abs2              -> dvd_abs_iff
   734 zdvd_refl              -> dvd_refl
   735 zdvd_trans             -> dvd_trans
   736 zdvd_zadd              -> dvd_add
   737 zdvd_zdiff             -> dvd_diff
   738 zdvd_zminus_iff        -> dvd_minus_iff
   739 zdvd_zminus2_iff       -> minus_dvd_iff
   740 zdvd_zmultD            -> dvd_mult_right
   741 zdvd_zmultD2           -> dvd_mult_left
   742 zdvd_zmult_mono        -> mult_dvd_mono
   743 zdvd_0_right           -> dvd_0_right
   744 zdvd_0_left            -> dvd_0_left_iff
   745 zdvd_1_left            -> one_dvd
   746 zminus_dvd_iff         -> minus_dvd_iff
   747 
   748 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   749 
   750 * The real numbers offer decimal input syntax: 12.34 is translated
   751 into 1234/10^2. This translation is not reversed upon output.
   752 
   753 * Theory Library/Polynomial defines an abstract type 'a poly of
   754 univariate polynomials with coefficients of type 'a.  In addition to
   755 the standard ring operations, it also supports div and mod.  Code
   756 generation is also supported, using list-style constructors.
   757 
   758 * Theory Library/Inner_Product defines a class of real_inner for real
   759 inner product spaces, with an overloaded operation inner :: 'a => 'a
   760 => real.  Class real_inner is a subclass of real_normed_vector from
   761 theory RealVector.
   762 
   763 * Theory Library/Product_Vector provides instances for the product
   764 type 'a * 'b of several classes from RealVector and Inner_Product.
   765 Definitions of addition, subtraction, scalar multiplication, norms,
   766 and inner products are included.
   767 
   768 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   769 addition to the field operations, numerals and case syntax are also
   770 supported.
   771 
   772 * Theory Library/Diagonalize provides constructive version of Cantor's
   773 first diagonalization argument.
   774 
   775 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   776 zlcm (for int); carried together from various gcd/lcm developements in
   777 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   778 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   779 may recover tupled syntax as follows:
   780 
   781     hide (open) const gcd
   782     abbreviation gcd where
   783       "gcd == (%(a, b). GCD.gcd a b)"
   784     notation (output)
   785       GCD.gcd ("gcd '(_, _')")
   786 
   787 The same works for lcm, zgcd, zlcm.
   788 
   789 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   790 instantiations for algebraic structures.  Removed some duplicate
   791 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   792 
   793 * ML antiquotation @{code} takes a constant as argument and generates
   794 corresponding code in background and inserts name of the corresponding
   795 resulting ML value/function/datatype constructor binding in place.
   796 All occurrences of @{code} with a single ML block are generated
   797 simultaneously.  Provides a generic and safe interface for
   798 instrumentalizing code generation.  See
   799 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   800 In future you ought to refrain from ad-hoc compiling generated SML
   801 code on the ML toplevel.  Note that (for technical reasons) @{code}
   802 cannot refer to constants for which user-defined serializations are
   803 set.  Refer to the corresponding ML counterpart directly in that
   804 cases.
   805 
   806 * Command 'rep_datatype': instead of theorem names the command now
   807 takes a list of terms denoting the constructors of the type to be
   808 represented as datatype.  The characteristic theorems have to be
   809 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   810 have disappeared in favour of existing ones:
   811 
   812     unit_induct                 ~> unit.induct
   813     prod_induct                 ~> prod.induct
   814     sum_induct                  ~> sum.induct
   815     Suc_Suc_eq                  ~> nat.inject
   816     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   817 
   818 
   819 *** HOL-Algebra ***
   820 
   821 * New locales for orders and lattices where the equivalence relation
   822 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   823 locales use a record structure with field eq for the equivalence.
   824 
   825 * New theory of factorial domains.
   826 
   827 * Units_l_inv and Units_r_inv are now simp rules by default.
   828 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   829 and/or r_inv will now also require deletion of these lemmas.
   830 
   831 * Renamed the following theorems, INCOMPATIBILITY:
   832 
   833 UpperD ~> Upper_memD
   834 LowerD ~> Lower_memD
   835 least_carrier ~> least_closed
   836 greatest_carrier ~> greatest_closed
   837 greatest_Lower_above ~> greatest_Lower_below
   838 one_zero ~> carrier_one_zero
   839 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   840 
   841 
   842 *** HOL-Nominal ***
   843 
   844 * Nominal datatypes can now contain type-variables.
   845 
   846 * Commands 'nominal_inductive' and 'equivariance' work with local
   847 theory targets.
   848 
   849 * Nominal primrec can now works with local theory targets and its
   850 specification syntax now conforms to the general format as seen in
   851 'inductive' etc.
   852 
   853 * Method "perm_simp" honours the standard simplifier attributes
   854 (no_asm), (no_asm_use) etc.
   855 
   856 * The new predicate #* is defined like freshness, except that on the
   857 left hand side can be a set or list of atoms.
   858 
   859 * Experimental command 'nominal_inductive2' derives strong induction
   860 principles for inductive definitions.  In contrast to
   861 'nominal_inductive', which can only deal with a fixed number of
   862 binders, it can deal with arbitrary expressions standing for sets of
   863 atoms to be avoided.  The only inductive definition we have at the
   864 moment that needs this generalisation is the typing rule for Lets in
   865 the algorithm W:
   866 
   867  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   868  -----------------------------------------------------------------
   869          Gamma |- Let x be t1 in t2 : T2
   870 
   871 In this rule one wants to avoid all the binders that are introduced by
   872 "close Gamma T1".  We are looking for other examples where this
   873 feature might be useful.  Please let us know.
   874 
   875 
   876 *** HOLCF ***
   877 
   878 * Reimplemented the simplification procedure for proving continuity
   879 subgoals.  The new simproc is extensible; users can declare additional
   880 continuity introduction rules with the attribute [cont2cont].
   881 
   882 * The continuity simproc now uses a different introduction rule for
   883 solving continuity subgoals on terms with lambda abstractions.  In
   884 some rare cases the new simproc may fail to solve subgoals that the
   885 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   886 Potential INCOMPATIBILITY.
   887 
   888 * Command 'fixrec': specification syntax now conforms to the general
   889 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   890 examples.  INCOMPATIBILITY.
   891 
   892 
   893 *** ZF ***
   894 
   895 * Proof of Zorn's Lemma for partial orders.
   896 
   897 
   898 *** ML ***
   899 
   900 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   901 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   902 depends on multithreading, so timouts will not work before Poly/ML
   903 5.2.1!
   904 
   905 * High-level support for concurrent ML programming, see
   906 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   907 particularly convenient to organize independent functional
   908 computations.  The concept of "synchronized variables" provides a
   909 higher-order interface for components with shared state, avoiding the
   910 delicate details of mutexes and condition variables.  (Requires
   911 Poly/ML 5.2.1 or later.)
   912 
   913 * ML bindings produced via Isar commands are stored within the Isar
   914 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   915 become thread-safe and work with undo as expected (concerning
   916 top-level bindings, not side-effects on global references).
   917 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   918 compiler at runtime; really global bindings need to be given outside a
   919 theory.  (Requires Poly/ML 5.2 or later.)
   920 
   921 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   922 context.  Top-level ML bindings are stored within the proof context in
   923 a purely sequential fashion, disregarding the nested proof structure.
   924 ML bindings introduced by 'ML_prf' are discarded at the end of the
   925 proof.  (Requires Poly/ML 5.2 or later.)
   926 
   927 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   928 and Method.setup, as well as Isar commands 'attribute_setup' and
   929 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   930 existing code accordingly, or use plain 'setup' together with old
   931 Method.add_method.
   932 
   933 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   934 to 'a -> thm, while results are always tagged with an authentic oracle
   935 name.  The Isar command 'oracle' is now polymorphic, no argument type
   936 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   937 accordingly.  Note that extra performance may be gained by producing
   938 the cterm carefully, avoiding slow Thm.cterm_of.
   939 
   940 * Simplified interface for defining document antiquotations via
   941 ThyOutput.antiquotation, ThyOutput.output, and optionally
   942 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   943 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   944 examples.
   945 
   946 * More systematic treatment of long names, abstract name bindings, and
   947 name space operations.  Basic operations on qualified names have been
   948 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   949 Long_Name.append.  Old type bstring has been mostly replaced by
   950 abstract type binding (see structure Binding), which supports precise
   951 qualification by packages and local theory targets, as well as proper
   952 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   953 bstring values into Binding.name, or better pass through abstract
   954 bindings everywhere.  See further src/Pure/General/long_name.ML,
   955 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   956 
   957 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   958 LocalTheory.note etc.) now refer to the *full* internal name, not the
   959 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   960 
   961 * Disposed old type and term read functions (Sign.read_def_typ,
   962 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   963 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   964 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   965 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   966 resort for legacy applications.
   967 
   968 * Disposed old declarations, tactics, tactic combinators that refer to
   969 the simpset or claset of an implicit theory (such as Addsimps,
   970 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   971 embedded ML text, or local_simpset_of with a proper context passed as
   972 explicit runtime argument.
   973 
   974 * Rules and tactics that read instantiations (read_instantiate,
   975 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   976 context, which is required for parsing and type-checking.  Moreover,
   977 the variables are specified as plain indexnames, not string encodings
   978 thereof.  INCOMPATIBILITY.
   979 
   980 * Generic Toplevel.add_hook interface allows to analyze the result of
   981 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   982 for theorem dependency output of transactions resulting in a new
   983 theory state.
   984 
   985 * ML antiquotations: block-structured compilation context indicated by
   986 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   987 
   988   @{binding name}                         - basic name binding
   989   @{let ?pat = term}                      - term abbreviation (HO matching)
   990   @{note name = fact}                     - fact abbreviation
   991   @{thm fact}                             - singleton fact (with attributes)
   992   @{thms fact}                            - general fact (with attributes)
   993   @{lemma prop by method}                 - singleton goal
   994   @{lemma prop by meth1 meth2}            - singleton goal
   995   @{lemma prop1 ... propN by method}      - general goal
   996   @{lemma prop1 ... propN by meth1 meth2} - general goal
   997   @{lemma (open) ...}                     - open derivation
   998 
   999 
  1000 *** System ***
  1001 
  1002 * The Isabelle "emacs" tool provides a specific interface to invoke
  1003 Proof General / Emacs, with more explicit failure if that is not
  1004 installed (the old isabelle-interface script silently falls back on
  1005 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1006 installation location of the Proof General distribution.
  1007 
  1008 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1009 the Isabelle process into a JVM/Scala application.  See
  1010 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1011 process wrapper has been discontinued.)
  1012 
  1013 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1014 
  1015 * Various status messages (with exact source position information) are
  1016 emitted, if proper markup print mode is enabled.  This allows
  1017 user-interface components to provide detailed feedback on internal
  1018 prover operations.
  1019 
  1020 
  1021 
  1022 New in Isabelle2008 (June 2008)
  1023 -------------------------------
  1024 
  1025 *** General ***
  1026 
  1027 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1028 and updated, with formally checked references as hyperlinks.
  1029 
  1030 * Theory loader: use_thy (and similar operations) no longer set the
  1031 implicit ML context, which was occasionally hard to predict and in
  1032 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1033 provides a proper context already.
  1034 
  1035 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1036 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1037 'use' within a theory file will do the job.
  1038 
  1039 * Name space merge now observes canonical order, i.e. the second space
  1040 is inserted into the first one, while existing entries in the first
  1041 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1042 swap theory imports.
  1043 
  1044 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1045 INCOMPATIBILITY in identifier syntax etc.
  1046 
  1047 * Outer syntax: string tokens no longer admit escaped white space,
  1048 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1049 white space without escapes.
  1050 
  1051 * Outer syntax: string tokens may contain arbitrary character codes
  1052 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1053 "foo_bar".
  1054 
  1055 
  1056 *** Pure ***
  1057 
  1058 * Context-dependent token translations.  Default setup reverts locally
  1059 fixed variables, and adds hilite markup for undeclared frees.
  1060 
  1061 * Unused theorems can be found using the new command 'unused_thms'.
  1062 There are three ways of invoking it:
  1063 
  1064 (1) unused_thms
  1065      Only finds unused theorems in the current theory.
  1066 
  1067 (2) unused_thms thy_1 ... thy_n -
  1068      Finds unused theorems in the current theory and all of its ancestors,
  1069      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1070 
  1071 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1072      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1073      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1074      their ancestors.
  1075 
  1076 In order to increase the readability of the list produced by
  1077 unused_thms, theorems that have been created by a particular instance
  1078 of a theory command such as 'inductive' or 'function' are considered
  1079 to belong to the same "group", meaning that if at least one theorem in
  1080 this group is used, the other theorems in the same group are no longer
  1081 reported as unused.  Moreover, if all theorems in the group are
  1082 unused, only one theorem in the group is displayed.
  1083 
  1084 Note that proof objects have to be switched on in order for
  1085 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1086 usually the case when using Proof General with the default settings).
  1087 
  1088 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1089 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1090 duplicate fact bindings, or even accidental fact duplications.  Note
  1091 that tools may maintain dynamically scoped facts systematically, using
  1092 PureThy.add_thms_dynamic.
  1093 
  1094 * Command 'hide' now allows to hide from "fact" name space as well.
  1095 
  1096 * Eliminated destructive theorem database, simpset, claset, and
  1097 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1098 update of theories within ML code.
  1099 
  1100 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1101 INCOMPATIBILITY, object-logics depending on former Pure require
  1102 additional setup PureThy.old_appl_syntax_setup; object-logics
  1103 depending on former CPure need to refer to Pure.
  1104 
  1105 * Commands 'use' and 'ML' are now purely functional, operating on
  1106 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1107 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1108 INCOMPATIBILITY.
  1109 
  1110 * Command 'setup': discontinued implicit version with ML reference.
  1111 
  1112 * Instantiation target allows for simultaneous specification of class
  1113 instance operations together with an instantiation proof.
  1114 Type-checking phase allows to refer to class operations uniformly.
  1115 See src/HOL/Complex/Complex.thy for an Isar example and
  1116 src/HOL/Library/Eval.thy for an ML example.
  1117 
  1118 * Indexing of literal facts: be more serious about including only
  1119 facts from the visible specification/proof context, but not the
  1120 background context (locale etc.).  Affects `prop` notation and method
  1121 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1122 situations.
  1123 
  1124 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1125 "(open)" option, which used to expose internal bound variables to the
  1126 proof text.
  1127 
  1128 * Isar statements: removed obsolete case "rule_context".
  1129 INCOMPATIBILITY, better use explicit fixes/assumes.
  1130 
  1131 * Locale proofs: default proof step now includes 'unfold_locales';
  1132 hence 'proof' without argument may be used to unfold locale
  1133 predicates.
  1134 
  1135 
  1136 *** Document preparation ***
  1137 
  1138 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1139 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1140 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1141 spot); renamed link color from "darkblue" to "linkcolor" (default
  1142 value unchanged, can be redefined via \definecolor); no longer sets
  1143 "a4paper" option (unnecessary or even intrusive).
  1144 
  1145 * Antiquotation @{lemma A method} proves proposition A by the given
  1146 method (either a method name or a method name plus (optional) method
  1147 arguments in parentheses) and prints A just like @{prop A}.
  1148 
  1149 
  1150 *** HOL ***
  1151 
  1152 * New primrec package.  Specification syntax conforms in style to
  1153 definition/function/....  No separate induction rule is provided.  The
  1154 "primrec" command distinguishes old-style and new-style specifications
  1155 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1156 When adjusting theories, beware: constants stemming from new-style
  1157 primrec specifications have authentic syntax.
  1158 
  1159 * Metis prover is now an order of magnitude faster, and also works
  1160 with multithreading.
  1161 
  1162 * Metis: the maximum number of clauses that can be produced from a
  1163 theorem is now given by the attribute max_clauses.  Theorems that
  1164 exceed this number are ignored, with a warning printed.
  1165 
  1166 * Sledgehammer no longer produces structured proofs by default. To
  1167 enable, declare [[sledgehammer_full = true]].  Attributes
  1168 reconstruction_modulus, reconstruction_sorts renamed
  1169 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1170 
  1171 * Method "induct_scheme" derives user-specified induction rules
  1172 from well-founded induction and completeness of patterns. This factors
  1173 out some operations that are done internally by the function package
  1174 and makes them available separately.  See
  1175 src/HOL/ex/Induction_Scheme.thy for examples.
  1176 
  1177 * More flexible generation of measure functions for termination
  1178 proofs: Measure functions can be declared by proving a rule of the
  1179 form "is_measure f" and giving it the [measure_function] attribute.
  1180 The "is_measure" predicate is logically meaningless (always true), and
  1181 just guides the heuristic.  To find suitable measure functions, the
  1182 termination prover sets up the goal "is_measure ?f" of the appropriate
  1183 type and generates all solutions by prolog-style backwards proof using
  1184 the declared rules.
  1185 
  1186 This setup also deals with rules like 
  1187 
  1188   "is_measure f ==> is_measure (list_size f)"
  1189 
  1190 which accommodates nested datatypes that recurse through lists.
  1191 Similar rules are predeclared for products and option types.
  1192 
  1193 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1194 
  1195   INCOMPATIBILITIES:
  1196 
  1197   - Definitions of overloaded constants on sets have to be replaced by
  1198     definitions on => and bool.
  1199 
  1200   - Some definitions of overloaded operators on sets can now be proved
  1201     using the definitions of the operators on => and bool.  Therefore,
  1202     the following theorems have been renamed:
  1203 
  1204       subset_def   -> subset_eq
  1205       psubset_def  -> psubset_eq
  1206       set_diff_def -> set_diff_eq
  1207       Compl_def    -> Compl_eq
  1208       Sup_set_def  -> Sup_set_eq
  1209       Inf_set_def  -> Inf_set_eq
  1210       sup_set_def  -> sup_set_eq
  1211       inf_set_def  -> inf_set_eq
  1212 
  1213   - Due to the incompleteness of the HO unification algorithm, some
  1214     rules such as subst may require manual instantiation, if some of
  1215     the unknowns in the rule is a set.
  1216 
  1217   - Higher order unification and forward proofs:
  1218     The proof pattern
  1219 
  1220       have "P (S::'a set)" <...>
  1221       then have "EX S. P S" ..
  1222 
  1223     no longer works (due to the incompleteness of the HO unification
  1224     algorithm) and must be replaced by the pattern
  1225 
  1226       have "EX S. P S"
  1227       proof
  1228         show "P S" <...>
  1229       qed
  1230 
  1231   - Calculational reasoning with subst (or similar rules):
  1232     The proof pattern
  1233 
  1234       have "P (S::'a set)" <...>
  1235       also have "S = T" <...>
  1236       finally have "P T" .
  1237 
  1238     no longer works (for similar reasons as the previous example) and
  1239     must be replaced by something like
  1240 
  1241       have "P (S::'a set)" <...>
  1242       moreover have "S = T" <...>
  1243       ultimately have "P T" by simp
  1244 
  1245   - Tactics or packages written in ML code:
  1246     Code performing pattern matching on types via
  1247 
  1248       Type ("set", [T]) => ...
  1249 
  1250     must be rewritten. Moreover, functions like strip_type or
  1251     binder_types no longer return the right value when applied to a
  1252     type of the form
  1253 
  1254       T1 => ... => Tn => U => bool
  1255 
  1256     rather than
  1257 
  1258       T1 => ... => Tn => U set
  1259 
  1260 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1261 Wellfounded_Relations to theory Wellfounded.
  1262 
  1263 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1264 
  1265 * Class finite no longer treats UNIV as class parameter.  Use class
  1266 enum from theory Library/Enum instead to achieve a similar effect.
  1267 INCOMPATIBILITY.
  1268 
  1269 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1270 and "Cons".  INCOMPATIBILITY.
  1271 
  1272 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1273 Potential INCOMPATIBILITY.
  1274 
  1275 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1276 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1277 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1278 
  1279 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1280 the same name in theory Orderings:
  1281 
  1282   less_trans
  1283   less_linear
  1284   le_imp_less_or_eq
  1285   le_less_trans
  1286   less_le_trans
  1287   less_not_sym
  1288   less_asym
  1289 
  1290 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1291 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1292 and different variable names.
  1293 
  1294 * Library/Option_ord.thy: Canonical order on option type.
  1295 
  1296 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1297 finite maps.
  1298 
  1299 * Library/Countable.thy: Type class for countable types.
  1300 
  1301 * Theory Int: The representation of numerals has changed.  The infix
  1302 operator BIT and the bit datatype with constructors B0 and B1 have
  1303 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1304 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1305 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1306 accordingly.
  1307 
  1308 * Theory Nat: definition of <= and < on natural numbers no longer
  1309 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1310 le_def and less_def have disappeared.  Consider lemmas not_less
  1311 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1312 
  1313 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1314 (whose purpose mainly is for various fold_set functionals) have been
  1315 abandoned in favor of the existing algebraic classes
  1316 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1317 lower_semilattice (resp. upper_semilattice) and linorder.
  1318 INCOMPATIBILITY.
  1319 
  1320 * Theory Transitive_Closure: induct and cases rules now declare proper
  1321 case_names ("base" and "step").  INCOMPATIBILITY.
  1322 
  1323 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1324 lattices.  The form set-specific version is available as
  1325 Inductive.lfp_ordinal_induct_set.
  1326 
  1327 * Renamed theorems "power.simps" to "power_int.simps".
  1328 INCOMPATIBILITY.
  1329 
  1330 * Class semiring_div provides basic abstract properties of semirings
  1331 with division and modulo operations.  Subsumes former class dvd_mod.
  1332 
  1333 * Merged theories IntDef, Numeral and IntArith into unified theory
  1334 Int.  INCOMPATIBILITY.
  1335 
  1336 * Theory Library/Code_Index: type "index" now represents natural
  1337 numbers rather than integers.  INCOMPATIBILITY.
  1338 
  1339 * New class "uminus" with operation "uminus" (split of from class
  1340 "minus" which now only has operation "minus", binary).
  1341 INCOMPATIBILITY.
  1342 
  1343 * Constants "card", "internal_split", "option_map" now with authentic
  1344 syntax.  INCOMPATIBILITY.
  1345 
  1346 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1347 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1348 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1349 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1350 Sup_set_def, le_def, less_def, option_map_def now with object
  1351 equality.  INCOMPATIBILITY.
  1352 
  1353 * Records. Removed K_record, and replaced it by pure lambda term
  1354 %x. c. The simplifier setup is now more robust against eta expansion.
  1355 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1356 
  1357 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1358 
  1359 * Library/ListVector: new theory of arithmetic vector operations.
  1360 
  1361 * Library/Order_Relation: new theory of various orderings as sets of
  1362 pairs.  Defines preorders, partial orders, linear orders and
  1363 well-orders on sets and on types.
  1364 
  1365 
  1366 *** ZF ***
  1367 
  1368 * Renamed some theories to allow to loading both ZF and HOL in the
  1369 same session:
  1370 
  1371   Datatype  -> Datatype_ZF
  1372   Inductive -> Inductive_ZF
  1373   Int       -> Int_ZF
  1374   IntDiv    -> IntDiv_ZF
  1375   Nat       -> Nat_ZF
  1376   List      -> List_ZF
  1377   Main      -> Main_ZF
  1378 
  1379 INCOMPATIBILITY: ZF theories that import individual theories below
  1380 Main might need to be adapted.  Regular theory Main is still
  1381 available, as trivial extension of Main_ZF.
  1382 
  1383 
  1384 *** ML ***
  1385 
  1386 * ML within Isar: antiquotation @{const name} or @{const
  1387 name(typargs)} produces statically-checked Const term.
  1388 
  1389 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1390 (of the same name).  Removed obsolete print command.
  1391 
  1392 * Removed obsolete "use_legacy_bindings" function.
  1393 
  1394 * The ``print mode'' is now a thread-local value derived from a global
  1395 template (the former print_mode reference), thus access becomes
  1396 non-critical.  The global print_mode reference is for session
  1397 management only; user-code should use print_mode_value,
  1398 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1399 
  1400 * Functions system/system_out provide a robust way to invoke external
  1401 shell commands, with propagation of interrupts (requires Poly/ML
  1402 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1403 
  1404 
  1405 *** System ***
  1406 
  1407 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1408 in accordance with Proof General 3.7, which prefers GNU emacs.
  1409 
  1410 * isatool tty runs Isabelle process with plain tty interaction;
  1411 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1412 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1413 
  1414 * isatool browser now works with Cygwin as well, using general
  1415 "javapath" function defined in Isabelle process environment.
  1416 
  1417 * YXML notation provides a simple and efficient alternative to
  1418 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1419 isatool yxml as described in the Isabelle system manual.
  1420 
  1421 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1422 provides general wrapper for managing an Isabelle process in a robust
  1423 fashion, with ``cooked'' output from stdin/stderr.
  1424 
  1425 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1426 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1427 
  1428 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1429 way of changing the user's settings is via
  1430 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1431 script.
  1432 
  1433 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1434 cores of the underlying machine, which is a good starting point for
  1435 optimal performance tuning.  The corresponding usedir option -M allows
  1436 "max" as an alias for "0".  WARNING: does not work on certain versions
  1437 of Mac OS (with Poly/ML 5.1).
  1438 
  1439 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1440 adverse effect of Isabelle flooding interactive front-ends (notably
  1441 ProofGeneral / XEmacs).
  1442 
  1443 
  1444 
  1445 New in Isabelle2007 (November 2007)
  1446 -----------------------------------
  1447 
  1448 *** General ***
  1449 
  1450 * More uniform information about legacy features, notably a
  1451 warning/error of "Legacy feature: ...", depending on the state of the
  1452 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1453 legacy features will disappear eventually.
  1454 
  1455 * Theory syntax: the header format ``theory A = B + C:'' has been
  1456 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1457 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1458 
  1459 * Theory syntax: the old non-Isar theory file format has been
  1460 discontinued altogether.  Note that ML proof scripts may still be used
  1461 with Isar theories; migration is usually quite simple with the ML
  1462 function use_legacy_bindings.  INCOMPATIBILITY.
  1463 
  1464 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1465 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1466 quotes.
  1467 
  1468 * Theory loader: be more serious about observing the static theory
  1469 header specifications (including optional directories), but not the
  1470 accidental file locations of previously successful loads.  The strict
  1471 update policy of former update_thy is now already performed by
  1472 use_thy, so the former has been removed; use_thys updates several
  1473 theories simultaneously, just as 'imports' within a theory header
  1474 specification, but without merging the results.  Potential
  1475 INCOMPATIBILITY: may need to refine theory headers and commands
  1476 ROOT.ML which depend on load order.
  1477 
  1478 * Theory loader: optional support for content-based file
  1479 identification, instead of the traditional scheme of full physical
  1480 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1481 (cf. the system manual).  The new scheme allows to work with
  1482 non-finished theories in persistent session images, such that source
  1483 files may be moved later on without requiring reloads.
  1484 
  1485 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1486 file (with the same base name as the theory) are considered a legacy
  1487 feature, which will disappear eventually. Even now, the theory loader
  1488 no longer maintains dependencies on such files.
  1489 
  1490 * Syntax: the scope for resolving ambiguities via type-inference is
  1491 now limited to individual terms, instead of whole simultaneous
  1492 specifications as before. This greatly reduces the complexity of the
  1493 syntax module and improves flexibility by separating parsing and
  1494 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1495 'fixes' etc.) are required in rare situations.
  1496 
  1497 * Syntax: constants introduced by new-style packages ('definition',
  1498 'abbreviation' etc.) are passed through the syntax module in
  1499 ``authentic mode''. This means that associated mixfix annotations
  1500 really stick to such constants, independently of potential name space
  1501 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1502 trees are represented slightly differently, may need to adapt syntax
  1503 translations accordingly. Use CONST marker in 'translations' and
  1504 @{const_syntax} antiquotation in 'parse_translation' etc.
  1505 
  1506 * Legacy goal package: reduced interface to the bare minimum required
  1507 to keep existing proof scripts running.  Most other user-level
  1508 functions are now part of the OldGoals structure, which is *not* open
  1509 by default (consider isatool expandshort before open OldGoals).
  1510 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1511 these tend to cause confusion about the actual goal (!) context being
  1512 used here, which is not necessarily the same as the_context().
  1513 
  1514 * Command 'find_theorems': supports "*" wild-card in "name:"
  1515 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1516 support a specific search form (see ProofGeneral/CHANGES).
  1517 
  1518 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1519 by default, which means that "prems" (and also "fixed variables") are
  1520 suppressed from proof state output.  Note that the ProofGeneral
  1521 settings mechanism allows to change and save options persistently, but
  1522 older versions of Isabelle will fail to start up if a negative prems
  1523 limit is imposed.
  1524 
  1525 * Local theory targets may be specified by non-nested blocks of
  1526 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1527 contain definitions, theorems etc., including any derived mechanism
  1528 that has been implemented on top of these primitives.  This concept
  1529 generalizes the existing ``theorem (in ...)'' towards more versatility
  1530 and scalability.
  1531 
  1532 * Proof General interface: proper undo of final 'end' command;
  1533 discontinued Isabelle/classic mode (ML proof scripts).
  1534 
  1535 
  1536 *** Document preparation ***
  1537 
  1538 * Added antiquotation @{theory name} which prints the given name,
  1539 after checking that it refers to a valid ancestor theory in the
  1540 current context.
  1541 
  1542 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1543 check the given source text as ML type/structure, printing verbatim.
  1544 
  1545 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1546 "c args == rhs" given in the current context.  (Any number of
  1547 arguments may be given on the LHS.)
  1548 
  1549 
  1550 *** Pure ***
  1551 
  1552 * The 'class' package offers a combination of axclass and locale to
  1553 achieve Haskell-like type classes in Isabelle.  Definitions and
  1554 theorems within a class context produce both relative results (with
  1555 implicit parameters according to the locale context), and polymorphic
  1556 constants with qualified polymorphism (according to the class
  1557 context).  Within the body context of a 'class' target, a separate
  1558 syntax layer ("user space type system") takes care of converting
  1559 between global polymorphic consts and internal locale representation.
  1560 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1561 "isatool doc classes" provides a tutorial.
  1562 
  1563 * Generic code generator framework allows to generate executable
  1564 code for ML and Haskell (including Isabelle classes).  A short usage
  1565 sketch:
  1566 
  1567     internal compilation:
  1568         export_code <list of constants (term syntax)> in SML
  1569     writing SML code to a file:
  1570         export_code <list of constants (term syntax)> in SML <filename>
  1571     writing OCaml code to a file:
  1572         export_code <list of constants (term syntax)> in OCaml <filename>
  1573     writing Haskell code to a bunch of files:
  1574         export_code <list of constants (term syntax)> in Haskell <filename>
  1575 
  1576     evaluating closed propositions to True/False using code generation:
  1577         method ``eval''
  1578 
  1579 Reasonable default setup of framework in HOL.
  1580 
  1581 Theorem attributs for selecting and transforming function equations theorems:
  1582 
  1583     [code fun]:        select a theorem as function equation for a specific constant
  1584     [code fun del]:    deselect a theorem as function equation for a specific constant
  1585     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1586     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1587 
  1588 User-defined serializations (target in {SML, OCaml, Haskell}):
  1589 
  1590     code_const <and-list of constants (term syntax)>
  1591       {(target) <and-list of const target syntax>}+
  1592 
  1593     code_type <and-list of type constructors>
  1594       {(target) <and-list of type target syntax>}+
  1595 
  1596     code_instance <and-list of instances>
  1597       {(target)}+
  1598         where instance ::= <type constructor> :: <class>
  1599 
  1600     code_class <and_list of classes>
  1601       {(target) <and-list of class target syntax>}+
  1602         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1603 
  1604 code_instance and code_class only are effective to target Haskell.
  1605 
  1606 For example usage see src/HOL/ex/Codegenerator.thy and
  1607 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1608 generation from Isabelle/HOL theories is available via "isatool doc
  1609 codegen".
  1610 
  1611 * Code generator: consts in 'consts_code' Isar commands are now
  1612 referred to by usual term syntax (including optional type
  1613 annotations).
  1614 
  1615 * Command 'no_translations' removes translation rules from theory
  1616 syntax.
  1617 
  1618 * Overloaded definitions are now actually checked for acyclic
  1619 dependencies.  The overloading scheme is slightly more general than
  1620 that of Haskell98, although Isabelle does not demand an exact
  1621 correspondence to type class and instance declarations.
  1622 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1623 exotic versions of overloading -- at the discretion of the user!
  1624 
  1625 Polymorphic constants are represented via type arguments, i.e. the
  1626 instantiation that matches an instance against the most general
  1627 declaration given in the signature.  For example, with the declaration
  1628 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1629 as c(nat).  Overloading is essentially simultaneous structural
  1630 recursion over such type arguments.  Incomplete specification patterns
  1631 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1632 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1633 Command 'print_theory' outputs the normalized system of recursive
  1634 equations, see section "definitions".
  1635 
  1636 * Configuration options are maintained within the theory or proof
  1637 context (with name and type bool/int/string), providing a very simple
  1638 interface to a poor-man's version of general context data.  Tools may
  1639 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1640 these values using Config.get etc.  Users may change options via an
  1641 associated attribute of the same name.  This form of context
  1642 declaration works particularly well with commands 'declare' or
  1643 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1644 very easy to avoid global references, which would not observe Isar
  1645 toplevel undo/redo and fail to work with multithreading.
  1646 
  1647 Various global ML references of Pure and HOL have been turned into
  1648 configuration options:
  1649 
  1650   Unify.search_bound		unify_search_bound
  1651   Unify.trace_bound		unify_trace_bound
  1652   Unify.trace_simp		unify_trace_simp
  1653   Unify.trace_types		unify_trace_types
  1654   Simplifier.simp_depth_limit	simp_depth_limit
  1655   Blast.depth_limit		blast_depth_limit
  1656   DatatypeProp.dtK		datatype_distinctness_limit
  1657   fast_arith_neq_limit  	fast_arith_neq_limit
  1658   fast_arith_split_limit	fast_arith_split_limit
  1659 
  1660 * Named collections of theorems may be easily installed as context
  1661 data using the functor NamedThmsFun (see also
  1662 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1663 attributes; there is also a toplevel print command.  This facility is
  1664 just a common case of general context data, which is the preferred way
  1665 for anything more complex than just a list of facts in canonical
  1666 order.
  1667 
  1668 * Isar: command 'declaration' augments a local theory by generic
  1669 declaration functions written in ML.  This enables arbitrary content
  1670 being added to the context, depending on a morphism that tells the
  1671 difference of the original declaration context wrt. the application
  1672 context encountered later on.
  1673 
  1674 * Isar: proper interfaces for simplification procedures.  Command
  1675 'simproc_setup' declares named simprocs (with match patterns, and body
  1676 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1677 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1678 
  1679 * Isar: an extra pair of brackets around attribute declarations
  1680 abbreviates a theorem reference involving an internal dummy fact,
  1681 which will be ignored later --- only the effect of the attribute on
  1682 the background context will persist.  This form of in-place
  1683 declarations is particularly useful with commands like 'declare' and
  1684 'using', for example ``have A using [[simproc a]] by simp''.
  1685 
  1686 * Isar: method "assumption" (and implicit closing of subproofs) now
  1687 takes simple non-atomic goal assumptions into account: after applying
  1688 an assumption as a rule the resulting subgoals are solved by atomic
  1689 assumption steps.  This is particularly useful to finish 'obtain'
  1690 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1691 without referring to the original premise "!!x. P x ==> thesis" in the
  1692 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1693 more permissive.
  1694 
  1695 * Isar: implicit use of prems from the Isar proof context is
  1696 considered a legacy feature.  Common applications like ``have A .''
  1697 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1698 referencing facts explicitly here improves readability and
  1699 maintainability of proof texts.
  1700 
  1701 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1702 the obtained context from the course of reasoning!  For example:
  1703 
  1704   assume "EX x y. A x & B y"   -- "any previous fact"
  1705   then guess x and y by clarify
  1706 
  1707 This technique is potentially adventurous, depending on the facts and
  1708 proof tools being involved here.
  1709 
  1710 * Isar: known facts from the proof context may be specified as literal
  1711 propositions, using ASCII back-quote syntax.  This works wherever
  1712 named facts used to be allowed so far, in proof commands, proof
  1713 methods, attributes etc.  Literal facts are retrieved from the context
  1714 according to unification of type and term parameters.  For example,
  1715 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1716 theorems in the current context, then these are valid literal facts:
  1717 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1718 
  1719 There is also a proof method "fact" which does the same composition
  1720 for explicit goal states, e.g. the following proof texts coincide with
  1721 certain special cases of literal facts:
  1722 
  1723   have "A" by fact                 ==  note `A`
  1724   have "A ==> B" by fact           ==  note `A ==> B`
  1725   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1726   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1727 
  1728 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1729 outer syntax.  Thus symbolic identifiers may be used without
  1730 additional white space in declarations like this: ``assume *: A''.
  1731 
  1732 * Isar: 'print_facts' prints all local facts of the current context,
  1733 both named and unnamed ones.
  1734 
  1735 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1736 
  1737   def x == "t" and y == "u"
  1738 
  1739 * Isar: added command 'unfolding', which is structurally similar to
  1740 'using', but affects both the goal state and facts by unfolding given
  1741 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1742 'unfolded' attribute may be replaced by first-class proof text.
  1743 
  1744 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1745 and command 'unfolding' now all support object-level equalities
  1746 (potentially conditional).  The underlying notion of rewrite rule is
  1747 analogous to the 'rule_format' attribute, but *not* that of the
  1748 Simplifier (which is usually more generous).
  1749 
  1750 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1751 premises of a theorem by n. Useful in conjunction with drule.
  1752 
  1753 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1754 method expression within a sandbox consisting of the first N
  1755 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1756 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1757 simplifies all new goals that emerge from applying rule foo to the
  1758 originally first one.
  1759 
  1760 * Isar: schematic goals are no longer restricted to higher-order
  1761 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1762 expected.
  1763 
  1764 * Isar: the conclusion of a long theorem statement is now either
  1765 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1766 (essentially a disjunction of cases with local parameters and
  1767 assumptions).  The latter allows to express general elimination rules
  1768 adequately; in this notation common elimination rules look like this:
  1769 
  1770   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1771     assumes "EX x. P x"
  1772     obtains x where "P x"
  1773 
  1774   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1775     assumes "A & B"
  1776     obtains A and B
  1777 
  1778   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1779     assumes "A | B"
  1780     obtains
  1781       A
  1782     | B
  1783 
  1784 The subsequent classical rules even refer to the formal "thesis"
  1785 explicitly:
  1786 
  1787   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1788     obtains "~ thesis"
  1789 
  1790   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1791     obtains "thesis ==> something"
  1792 
  1793 The actual proof of an 'obtains' statement is analogous to that of the
  1794 Isar proof element 'obtain', only that there may be several cases.
  1795 Optional case names may be specified in parentheses; these will be
  1796 available both in the present proof and as annotations in the
  1797 resulting rule, for later use with the 'cases' method (cf. attribute
  1798 case_names).
  1799 
  1800 * Isar: the assumptions of a long theorem statement are available as
  1801 "assms" fact in the proof context.  This is more appropriate than the
  1802 (historical) "prems", which refers to all assumptions of the current
  1803 context, including those from the target locale, proof body etc.
  1804 
  1805 * Isar: 'print_statement' prints theorems from the current theory or
  1806 proof context in long statement form, according to the syntax of a
  1807 top-level lemma.
  1808 
  1809 * Isar: 'obtain' takes an optional case name for the local context
  1810 introduction rule (default "that").
  1811 
  1812 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1813 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1814 to occur.
  1815 
  1816 * Pure: syntax "CONST name" produces a fully internalized constant
  1817 according to the current context.  This is particularly useful for
  1818 syntax translations that should refer to internal constant
  1819 representations independently of name spaces.
  1820 
  1821 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1822 instead of "FOO ". This allows multiple binder declarations to coexist
  1823 in the same context.  INCOMPATIBILITY.
  1824 
  1825 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1826 primitive that also works in a locale context (both for constants and
  1827 fixed variables). Type declaration and internal syntactic representation
  1828 of given constants retrieved from the context. Likewise, the
  1829 'no_notation' command allows to remove given syntax annotations from the
  1830 current context.
  1831 
  1832 * Isar/locales: new derived specification elements 'axiomatization',
  1833 'definition', 'abbreviation', which support type-inference, admit
  1834 object-level specifications (equality, equivalence).  See also the
  1835 isar-ref manual.  Examples:
  1836 
  1837   axiomatization
  1838     eq  (infix "===" 50) where
  1839     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1840 
  1841   definition "f x y = x + y + 1"
  1842   definition g where "g x = f x x"
  1843 
  1844   abbreviation
  1845     neq  (infix "=!=" 50) where
  1846     "x =!= y == ~ (x === y)"
  1847 
  1848 These specifications may be also used in a locale context.  Then the
  1849 constants being introduced depend on certain fixed parameters, and the
  1850 constant name is qualified by the locale base name.  An internal
  1851 abbreviation takes care for convenient input and output, making the
  1852 parameters implicit and using the original short name.  See also
  1853 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1854 entities from a monomorphic theory.
  1855 
  1856 Presently, abbreviations are only available 'in' a target locale, but
  1857 not inherited by general import expressions.  Also note that
  1858 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1859 'translations' in common applications.  The "no_abbrevs" print mode
  1860 prevents folding of abbreviations in term output.
  1861 
  1862 Concrete syntax is attached to specified constants in internal form,
  1863 independently of name spaces.  The parse tree representation is
  1864 slightly different -- use 'notation' instead of raw 'syntax', and
  1865 'translations' with explicit "CONST" markup to accommodate this.
  1866 
  1867 * Pure/Isar: unified syntax for new-style specification mechanisms
  1868 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1869 full type inference and dummy patterns ("_").  For example:
  1870 
  1871   definition "K x _ = x"
  1872 
  1873   inductive conj for A B
  1874   where "A ==> B ==> conj A B"
  1875 
  1876 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1877 the current context.  Print mode "no_abbrevs" prevents inversion of
  1878 abbreviations on output.
  1879 
  1880 * Isar/locales: improved parameter handling: use of locales "var" and
  1881 "struct" no longer necessary; - parameter renamings are no longer
  1882 required to be injective.  For example, this allows to define
  1883 endomorphisms as locale endom = homom mult mult h.
  1884 
  1885 * Isar/locales: changed the way locales with predicates are defined.
  1886 Instead of accumulating the specification, the imported expression is
  1887 now an interpretation.  INCOMPATIBILITY: different normal form of
  1888 locale expressions.  In particular, in interpretations of locales with
  1889 predicates, goals repesenting already interpreted fragments are not
  1890 removed automatically.  Use methods `intro_locales' and
  1891 `unfold_locales'; see below.
  1892 
  1893 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1894 provide backward reasoning on locales predicates.  The methods are
  1895 aware of interpretations and discharge corresponding goals.
  1896 `intro_locales' is less aggressive then `unfold_locales' and does not
  1897 unfold predicates to assumptions.
  1898 
  1899 * Isar/locales: the order in which locale fragments are accumulated
  1900 has changed.  This enables to override declarations from fragments due
  1901 to interpretations -- for example, unwanted simp rules.
  1902 
  1903 * Isar/locales: interpretation in theories and proof contexts has been
  1904 extended.  One may now specify (and prove) equations, which are
  1905 unfolded in interpreted theorems.  This is useful for replacing
  1906 defined concepts (constants depending on locale parameters) by
  1907 concepts already existing in the target context.  Example:
  1908 
  1909   interpretation partial_order ["op <= :: [int, int] => bool"]
  1910     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1911 
  1912 Typically, the constant `partial_order.less' is created by a
  1913 definition specification element in the context of locale
  1914 partial_order.
  1915 
  1916 * Method "induct": improved internal context management to support
  1917 local fixes and defines on-the-fly. Thus explicit meta-level
  1918 connectives !!  and ==> are rarely required anymore in inductive goals
  1919 (using object-logic connectives for this purpose has been long
  1920 obsolete anyway). Common proof patterns are explained in
  1921 src/HOL/Induct/Common_Patterns.thy, see also
  1922 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1923 examples.
  1924 
  1925 * Method "induct": improved handling of simultaneous goals. Instead of
  1926 introducing object-level conjunction, the statement is now split into
  1927 several conclusions, while the corresponding symbolic cases are nested
  1928 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1929 see src/HOL/Induct/Common_Patterns.thy, for example.
  1930 
  1931 * Method "induct": mutual induction rules are now specified as a list
  1932 of rule sharing the same induction cases. HOL packages usually provide
  1933 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1934 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1935 mutual induction rules differently, i.e. like this:
  1936 
  1937   (induct rule: foo_bar.inducts)
  1938   (induct set: foo bar)
  1939   (induct pred: foo bar)
  1940   (induct type: foo bar)
  1941 
  1942 The ML function ProjectRule.projections turns old-style rules into the
  1943 new format.
  1944 
  1945 * Method "coinduct": dual of induction, see
  1946 src/HOL/Library/Coinductive_List.thy for various examples.
  1947 
  1948 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1949 considered a legacy feature.
  1950 
  1951 * Attribute "symmetric" produces result with standardized schematic
  1952 variables (index 0).  Potential INCOMPATIBILITY.
  1953 
  1954 * Simplifier: by default the simplifier trace only shows top level
  1955 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1956 default. Thus there is less danger of being flooded by the trace. The
  1957 trace indicates where parts have been suppressed.
  1958   
  1959 * Provers/classical: removed obsolete classical version of elim_format
  1960 attribute; classical elim/dest rules are now treated uniformly when
  1961 manipulating the claset.
  1962 
  1963 * Provers/classical: stricter checks to ensure that supplied intro,
  1964 dest and elim rules are well-formed; dest and elim rules must have at
  1965 least one premise.
  1966 
  1967 * Provers/classical: attributes dest/elim/intro take an optional
  1968 weight argument for the rule (just as the Pure versions).  Weights are
  1969 ignored by automated tools, but determine the search order of single
  1970 rule steps.
  1971 
  1972 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1973 where the body does not mention the bound variable.  Note that dummy
  1974 patterns implicitly depend on their context of bounds, which makes
  1975 "{_. _}" match any set comprehension as expected.  Potential
  1976 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1977 constant "_idtdummy" in the binding position.
  1978 
  1979 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1980 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1981 for example "A -> B" => "Pi A (%_. B)".
  1982 
  1983 * Pure: 'class_deps' command visualizes the subclass relation, using
  1984 the graph browser tool.
  1985 
  1986 * Pure: 'print_theory' now suppresses certain internal declarations by
  1987 default; use '!' option for full details.
  1988 
  1989 
  1990 *** HOL ***
  1991 
  1992 * Method "metis" proves goals by applying the Metis general-purpose
  1993 resolution prover (see also http://gilith.com/software/metis/).
  1994 Examples are in the directory MetisExamples.  WARNING: the
  1995 Isabelle/HOL-Metis integration does not yet work properly with
  1996 multi-threading.
  1997   
  1998 * Command 'sledgehammer' invokes external automatic theorem provers as
  1999 background processes.  It generates calls to the "metis" method if
  2000 successful. These can be pasted into the proof.  Users do not have to
  2001 wait for the automatic provers to return.  WARNING: does not really
  2002 work with multi-threading.
  2003 
  2004 * New "auto_quickcheck" feature tests outermost goal statements for
  2005 potential counter-examples.  Controlled by ML references
  2006 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2007 5000 milliseconds).  Fails silently if statements is outside of
  2008 executable fragment, or any other codgenerator problem occurs.
  2009 
  2010 * New constant "undefined" with axiom "undefined x = undefined".
  2011 
  2012 * Added class "HOL.eq", allowing for code generation with polymorphic
  2013 equality.
  2014 
  2015 * Some renaming of class constants due to canonical name prefixing in
  2016 the new 'class' package:
  2017 
  2018     HOL.abs ~> HOL.abs_class.abs
  2019     HOL.divide ~> HOL.divide_class.divide
  2020     0 ~> HOL.zero_class.zero
  2021     1 ~> HOL.one_class.one
  2022     op + ~> HOL.plus_class.plus
  2023     op - ~> HOL.minus_class.minus
  2024     uminus ~> HOL.minus_class.uminus
  2025     op * ~> HOL.times_class.times
  2026     op < ~> HOL.ord_class.less
  2027     op <= > HOL.ord_class.less_eq
  2028     Nat.power ~> Power.power_class.power
  2029     Nat.size ~> Nat.size_class.size
  2030     Numeral.number_of ~> Numeral.number_class.number_of
  2031     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2032     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2033     Orderings.min ~> Orderings.ord_class.min
  2034     Orderings.max ~> Orderings.ord_class.max
  2035     Divides.op div ~> Divides.div_class.div
  2036     Divides.op mod ~> Divides.div_class.mod
  2037     Divides.op dvd ~> Divides.div_class.dvd
  2038 
  2039 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2040 
  2041 a) User-defined constants using any of the names "plus", "minus",
  2042 "times", "less" or "less_eq". The standard syntax translations for
  2043 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2044 names.
  2045 
  2046 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2047 INCOMPATIBILITY: use more specific names.
  2048 
  2049 c) Permutative equations (e.g. "a + b = b + a")
  2050 Since the change of names also changes the order of terms, permutative
  2051 rewrite rules may get applied in a different order. Experience shows
  2052 that this is rarely the case (only two adaptions in the whole Isabelle
  2053 distribution).  INCOMPATIBILITY: rewrite proofs
  2054 
  2055 d) ML code directly refering to constant names
  2056 This in general only affects hand-written proof tactics, simprocs and
  2057 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2058 Consider using @{const_name} antiquotation.
  2059 
  2060 * New class "default" with associated constant "default".
  2061 
  2062 * Function "sgn" is now overloaded and available on int, real, complex
  2063 (and other numeric types), using class "sgn".  Two possible defs of
  2064 sgn are given as equational assumptions in the classes sgn_if and
  2065 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2066 INCOMPATIBILITY.
  2067 
  2068 * Locale "partial_order" now unified with class "order" (cf. theory
  2069 Orderings), added parameter "less".  INCOMPATIBILITY.
  2070 
  2071 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2072 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2073 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2074 
  2075 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2076 changed order of proof goals in instance proofs.
  2077 
  2078 * The transitivity reasoner for partial and linear orders is set up
  2079 for classes "order" and "linorder".  Instances of the reasoner are available
  2080 in all contexts importing or interpreting the corresponding locales.
  2081 Method "order" invokes the reasoner separately; the reasoner
  2082 is also integrated with the Simplifier as a solver.  Diagnostic
  2083 command 'print_orders' shows the available instances of the reasoner
  2084 in the current context.
  2085 
  2086 * Localized monotonicity predicate in theory "Orderings"; integrated
  2087 lemmas max_of_mono and min_of_mono with this predicate.
  2088 INCOMPATIBILITY.
  2089 
  2090 * Formulation of theorem "dense" changed slightly due to integration
  2091 with new class dense_linear_order.
  2092 
  2093 * Uniform lattice theory development in HOL.
  2094 
  2095     constants "meet" and "join" now named "inf" and "sup"
  2096     constant "Meet" now named "Inf"
  2097 
  2098     classes "meet_semilorder" and "join_semilorder" now named
  2099       "lower_semilattice" and "upper_semilattice"
  2100     class "lorder" now named "lattice"
  2101     class "comp_lat" now named "complete_lattice"
  2102 
  2103     Instantiation of lattice classes allows explicit definitions
  2104     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2105 
  2106   INCOMPATIBILITY.  Theorem renames:
  2107 
  2108     meet_left_le            ~> inf_le1
  2109     meet_right_le           ~> inf_le2
  2110     join_left_le            ~> sup_ge1
  2111     join_right_le           ~> sup_ge2
  2112     meet_join_le            ~> inf_sup_ord
  2113     le_meetI                ~> le_infI
  2114     join_leI                ~> le_supI
  2115     le_meet                 ~> le_inf_iff
  2116     le_join                 ~> ge_sup_conv
  2117     meet_idempotent         ~> inf_idem
  2118     join_idempotent         ~> sup_idem
  2119     meet_comm               ~> inf_commute
  2120     join_comm               ~> sup_commute
  2121     meet_leI1               ~> le_infI1
  2122     meet_leI2               ~> le_infI2
  2123     le_joinI1               ~> le_supI1
  2124     le_joinI2               ~> le_supI2
  2125     meet_assoc              ~> inf_assoc
  2126     join_assoc              ~> sup_assoc
  2127     meet_left_comm          ~> inf_left_commute
  2128     meet_left_idempotent    ~> inf_left_idem
  2129     join_left_comm          ~> sup_left_commute
  2130     join_left_idempotent    ~> sup_left_idem
  2131     meet_aci                ~> inf_aci
  2132     join_aci                ~> sup_aci
  2133     le_def_meet             ~> le_iff_inf
  2134     le_def_join             ~> le_iff_sup
  2135     join_absorp2            ~> sup_absorb2
  2136     join_absorp1            ~> sup_absorb1
  2137     meet_absorp1            ~> inf_absorb1
  2138     meet_absorp2            ~> inf_absorb2
  2139     meet_join_absorp        ~> inf_sup_absorb
  2140     join_meet_absorp        ~> sup_inf_absorb
  2141     distrib_join_le         ~> distrib_sup_le
  2142     distrib_meet_le         ~> distrib_inf_le
  2143 
  2144     add_meet_distrib_left   ~> add_inf_distrib_left
  2145     add_join_distrib_left   ~> add_sup_distrib_left
  2146     is_join_neg_meet        ~> is_join_neg_inf
  2147     is_meet_neg_join        ~> is_meet_neg_sup
  2148     add_meet_distrib_right  ~> add_inf_distrib_right
  2149     add_join_distrib_right  ~> add_sup_distrib_right
  2150     add_meet_join_distribs  ~> add_sup_inf_distribs
  2151     join_eq_neg_meet        ~> sup_eq_neg_inf
  2152     meet_eq_neg_join        ~> inf_eq_neg_sup
  2153     add_eq_meet_join        ~> add_eq_inf_sup
  2154     meet_0_imp_0            ~> inf_0_imp_0
  2155     join_0_imp_0            ~> sup_0_imp_0
  2156     meet_0_eq_0             ~> inf_0_eq_0
  2157     join_0_eq_0             ~> sup_0_eq_0
  2158     neg_meet_eq_join        ~> neg_inf_eq_sup
  2159     neg_join_eq_meet        ~> neg_sup_eq_inf
  2160     join_eq_if              ~> sup_eq_if
  2161 
  2162     mono_meet               ~> mono_inf
  2163     mono_join               ~> mono_sup
  2164     meet_bool_eq            ~> inf_bool_eq
  2165     join_bool_eq            ~> sup_bool_eq
  2166     meet_fun_eq             ~> inf_fun_eq
  2167     join_fun_eq             ~> sup_fun_eq
  2168     meet_set_eq             ~> inf_set_eq
  2169     join_set_eq             ~> sup_set_eq
  2170     meet1_iff               ~> inf1_iff
  2171     meet2_iff               ~> inf2_iff
  2172     meet1I                  ~> inf1I
  2173     meet2I                  ~> inf2I
  2174     meet1D1                 ~> inf1D1
  2175     meet2D1                 ~> inf2D1
  2176     meet1D2                 ~> inf1D2
  2177     meet2D2                 ~> inf2D2
  2178     meet1E                  ~> inf1E
  2179     meet2E                  ~> inf2E
  2180     join1_iff               ~> sup1_iff
  2181     join2_iff               ~> sup2_iff
  2182     join1I1                 ~> sup1I1
  2183     join2I1                 ~> sup2I1
  2184     join1I1                 ~> sup1I1
  2185     join2I2                 ~> sup1I2
  2186     join1CI                 ~> sup1CI
  2187     join2CI                 ~> sup2CI
  2188     join1E                  ~> sup1E
  2189     join2E                  ~> sup2E
  2190 
  2191     is_meet_Meet            ~> is_meet_Inf
  2192     Meet_bool_def           ~> Inf_bool_def
  2193     Meet_fun_def            ~> Inf_fun_def
  2194     Meet_greatest           ~> Inf_greatest
  2195     Meet_lower              ~> Inf_lower
  2196     Meet_set_def            ~> Inf_set_def
  2197 
  2198     Sup_def                 ~> Sup_Inf
  2199     Sup_bool_eq             ~> Sup_bool_def
  2200     Sup_fun_eq              ~> Sup_fun_def
  2201     Sup_set_eq              ~> Sup_set_def
  2202 
  2203     listsp_meetI            ~> listsp_infI
  2204     listsp_meet_eq          ~> listsp_inf_eq
  2205 
  2206     meet_min                ~> inf_min
  2207     join_max                ~> sup_max
  2208 
  2209 * Added syntactic class "size"; overloaded constant "size" now has
  2210 type "'a::size ==> bool"
  2211 
  2212 * Internal reorganisation of `size' of datatypes: size theorems
  2213 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2214 simplification rules by default!); theorems "prod.size" now named
  2215 "*.size".
  2216 
  2217 * Class "div" now inherits from class "times" rather than "type".
  2218 INCOMPATIBILITY.
  2219 
  2220 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2221 Linorder etc.  have disappeared; operations defined in terms of
  2222 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2223 
  2224 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2225 
  2226 * HOL-Word: New extensive library and type for generic, fixed size
  2227 machine words, with arithemtic, bit-wise, shifting and rotating
  2228 operations, reflection into int, nat, and bool lists, automation for
  2229 linear arithmetic (by automatic reflection into nat or int), including
  2230 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2231 arithmetic type classes, supporting automatic simplification of
  2232 numerals on all operations.
  2233 
  2234 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2235 
  2236 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2237 
  2238 * Code generator library theories:
  2239   - Code_Integer represents HOL integers by big integer literals in target
  2240     languages.
  2241   - Code_Char represents HOL characters by character literals in target
  2242     languages.
  2243   - Code_Char_chr like Code_Char, but also offers treatment of character
  2244     codes; includes Code_Integer.
  2245   - Executable_Set allows to generate code for finite sets using lists.
  2246   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2247     denominator).
  2248   - Executable_Real implements a subset of real numbers, namly those
  2249     representable by rational numbers.
  2250   - Efficient_Nat implements natural numbers by integers, which in general will
  2251     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2252     includes Code_Integer.
  2253   - Code_Index provides an additional datatype index which is mapped to
  2254     target-language built-in integers.
  2255   - Code_Message provides an additional datatype message_string which is isomorphic to
  2256     strings; messages are mapped to target-language strings.
  2257 
  2258 * New package for inductive predicates
  2259 
  2260   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2261 
  2262     inductive
  2263       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2264       for z_1 :: U_1 and ... and z_n :: U_m
  2265     where
  2266       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2267     | ...
  2268 
  2269   with full support for type-inference, rather than
  2270 
  2271     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2272 
  2273     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2274     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2275 
  2276     inductive "s z_1 ... z_m"
  2277     intros
  2278       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2279       ...
  2280 
  2281   For backward compatibility, there is a wrapper allowing inductive
  2282   sets to be defined with the new package via
  2283 
  2284     inductive_set
  2285       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2286       for z_1 :: U_1 and ... and z_n :: U_m
  2287     where
  2288       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2289     | ...
  2290 
  2291   or
  2292 
  2293     inductive_set
  2294       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2295       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2296       for z_1 :: U_1 and ... and z_n :: U_m
  2297     where
  2298       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2299     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2300     | ...
  2301 
  2302   if the additional syntax "p ..." is required.
  2303 
  2304   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2305   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2306 
  2307   INCOMPATIBILITIES:
  2308 
  2309   - Since declaration and definition of inductive sets or predicates
  2310     is no longer separated, abbreviations involving the newly
  2311     introduced sets or predicates must be specified together with the
  2312     introduction rules after the 'where' keyword (see above), rather
  2313     than before the actual inductive definition.
  2314 
  2315   - The variables in induction and elimination rules are now
  2316     quantified in the order of their occurrence in the introduction
  2317     rules, rather than in alphabetical order. Since this may break
  2318     some proofs, these proofs either have to be repaired, e.g. by
  2319     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2320     statements of the form
  2321 
  2322       case (rule_i a_i_1 ... a_i_{k_i})
  2323 
  2324     or the old order of quantification has to be restored by explicitly adding
  2325     meta-level quantifiers in the introduction rules, i.e.
  2326 
  2327       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2328 
  2329   - The format of the elimination rules is now
  2330 
  2331       p z_1 ... z_m x_1 ... x_n ==>
  2332         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2333         ==> ... ==> P
  2334 
  2335     for predicates and
  2336 
  2337       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2338         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2339         ==> ... ==> P
  2340 
  2341     for sets rather than
  2342 
  2343       x : s z_1 ... z_m ==>
  2344         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2345         ==> ... ==> P
  2346 
  2347     This may require terms in goals to be expanded to n-tuples
  2348     (e.g. using case_tac or simplification with the split_paired_all
  2349     rule) before the above elimination rule is applicable.
  2350 
  2351   - The elimination or case analysis rules for (mutually) inductive
  2352     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2353     list of rules "p_1_..._p_k.elims" is no longer available.
  2354 
  2355 * New package "function"/"fun" for general recursive functions,
  2356 supporting mutual and nested recursion, definitions in local contexts,
  2357 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2358 for small examples, and the separate tutorial on the function
  2359 package. The old recdef "package" is still available as before, but
  2360 users are encouraged to use the new package.
  2361 
  2362 * Method "lexicographic_order" automatically synthesizes termination
  2363 relations as lexicographic combinations of size measures. 
  2364 
  2365 * Case-expressions allow arbitrary constructor-patterns (including
  2366 "_") and take their order into account, like in functional
  2367 programming.  Internally, this is translated into nested
  2368 case-expressions; missing cases are added and mapped to the predefined
  2369 constant "undefined". In complicated cases printing may no longer show
  2370 the original input but the internal form. Lambda-abstractions allow
  2371 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2372 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2373 variable.
  2374 
  2375 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2376 is an abbreviation for "of_nat :: nat => int". The simplification
  2377 rules for "of_nat" have been changed to work like "int" did
  2378 previously.  Potential INCOMPATIBILITY:
  2379   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2380   - of_nat_diff and of_nat_mult are no longer default simp rules
  2381 
  2382 * Method "algebra" solves polynomial equations over (semi)rings using
  2383 Groebner bases. The (semi)ring structure is defined by locales and the
  2384 tool setup depends on that generic context. Installing the method for
  2385 a specific type involves instantiating the locale and possibly adding
  2386 declarations for computation on the coefficients.  The method is
  2387 already instantiated for natural numbers and for the axiomatic class
  2388 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2389 CALCULEMUS 2007 for the general principles underlying this
  2390 architecture of context-aware proof-tools.
  2391 
  2392 * Method "ferrack" implements quantifier elimination over
  2393 special-purpose dense linear orders using locales (analogous to
  2394 "algebra"). The method is already installed for class
  2395 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2396 rat, etc.
  2397 
  2398 * Former constant "List.op @" now named "List.append".  Use ML
  2399 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2400 circumvent possible incompatibilities when working on ML level.
  2401 
  2402 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2403 
  2404 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2405 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2406 
  2407 * New syntax for Haskell-like list comprehension (input only), eg.
  2408 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2409 
  2410 * The special syntax for function "filter" has changed from [x :
  2411 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2412 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2413 
  2414 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2415 defined on nat only, as an abbreviation for [a..<Suc b]
  2416 INCOMPATIBILITY.
  2417 
  2418 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2419 
  2420 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2421 
  2422 * New lemma collection field_simps (an extension of ring_simps) for
  2423 manipulating (in)equations involving division. Multiplies with all
  2424 denominators that can be proved to be non-zero (in equations) or
  2425 positive/negative (in inequations).
  2426 
  2427 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2428 have been improved and renamed to ring_simps, group_simps and
  2429 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2430 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2431 
  2432 * Theory Library/Commutative_Ring: switched from recdef to function
  2433 package; constants add, mul, pow now curried.  Infix syntax for
  2434 algebraic operations.
  2435 
  2436 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2437 INCOMPATIBILITY.
  2438 
  2439 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2440 INCOMPATIBILITY.
  2441 
  2442 * HOL/records: generalised field-update to take a function on the
  2443 field rather than the new value: r(|A := x|) is translated to A_update
  2444 (K x) r The K-combinator that is internally used is called K_record.
  2445 INCOMPATIBILITY: Usage of the plain update functions has to be
  2446 adapted.
  2447  
  2448 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2449 * x = 0, which are required for a semiring.  Richer structures do not
  2450 inherit from semiring_0 anymore, because this property is a theorem
  2451 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2452 there is more to prove, but this is mostly trivial.
  2453 
  2454 * Class "recpower" is generalized to arbitrary monoids, not just
  2455 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2456 commutativity or semiring properties additionally.
  2457 
  2458 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2459 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2460 better use 'abbreviation'.
  2461 
  2462 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2463 
  2464 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2465 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2466 significant changes for setting up numeral syntax for types:
  2467   - New constants Numeral.pred and Numeral.succ instead
  2468       of former Numeral.bin_pred and Numeral.bin_succ.
  2469   - Use integer operations instead of bin_add, bin_mult and so on.
  2470   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2471   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2472 
  2473 See src/HOL/Integ/IntArith.thy for an example setup.
  2474 
  2475 * Command 'normal_form' computes the normal form of a term that may
  2476 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2477 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2478 heavy-duty computations because the functions are compiled to ML
  2479 first.  Correspondingly, a method "normalization" is provided.  See
  2480 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2481 
  2482 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2483 25 like -->); output depends on the "iff" print_mode, the default is
  2484 "A = B" (with priority 50).
  2485 
  2486 * Relations less (<) and less_eq (<=) are also available on type bool.
  2487 Modified syntax to disallow nesting without explicit parentheses,
  2488 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2489 INCOMPATIBILITY.
  2490 
  2491 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2492 
  2493 * Relation composition operator "op O" now has precedence 75 and binds
  2494 stronger than union and intersection. INCOMPATIBILITY.
  2495 
  2496 * The old set interval syntax "{m..n(}" (and relatives) has been
  2497 removed.  Use "{m..<n}" (and relatives) instead.
  2498 
  2499 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2500 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2501 ``declare [[simproc del: neq]]''.
  2502 
  2503 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2504 True/False.
  2505 
  2506 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2507 
  2508 * Theorem setsum_mult renamed to setsum_right_distrib.
  2509 
  2510 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2511 ``rule'' method.
  2512 
  2513 * Reimplemented methods "sat" and "satx", with several improvements:
  2514 goals no longer need to be stated as "<prems> ==> False", equivalences
  2515 (i.e. "=" on type bool) are handled, variable names of the form
  2516 "lit_<n>" are no longer reserved, significant speedup.
  2517 
  2518 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2519 zChaff is still supported as well.
  2520 
  2521 * 'inductive' and 'datatype': provide projections of mutual rules,
  2522 bundled as foo_bar.inducts;
  2523 
  2524 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2525 Library.
  2526 
  2527 * Library: moved theory Accessible_Part to main HOL.
  2528 
  2529 * Library: added theory Coinductive_List of potentially infinite lists
  2530 as greatest fixed-point.
  2531 
  2532 * Library: added theory AssocList which implements (finite) maps as
  2533 association lists.
  2534 
  2535 * Method "evaluation" solves goals (i.e. a boolean expression)
  2536 efficiently by compiling it to ML.  The goal is "proved" (via an
  2537 oracle) if it evaluates to True.
  2538 
  2539 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2540 also when invoked by the simplifier.  This results in the Simplifier
  2541 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2542 Configuration option fast_arith_split_limit=0 recovers the old
  2543 behavior.
  2544 
  2545 * Support for hex (0x20) and binary (0b1001) numerals.
  2546 
  2547 * New method: reify eqs (t), where eqs are equations for an
  2548 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2549 parameter, computes a term s::'b and a list xs::'a list and proves the
  2550 theorem I xs s = t. This is also known as reification or quoting. The
  2551 resulting theorem is applied to the subgoal to substitute t with I xs
  2552 s.  If t is omitted, the subgoal itself is reified.
  2553 
  2554 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2555 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2556 where f is supposed to be a computable function (in the sense of code
  2557 generattion). The method uses reify to compute s and xs as above then
  2558 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2559 r and finally gets the theorem t = r, which is again applied to the
  2560 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2561 
  2562 * Reflection: Automatic reification now handels binding, an example is
  2563 available in src/HOL/ex/ReflectionEx.thy
  2564 
  2565 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2566 command 'statespace' that is similar to 'record', but introduces an
  2567 abstract specification based on the locale infrastructure instead of
  2568 HOL types.  This leads to extra flexibility in composing state spaces,
  2569 in particular multiple inheritance and renaming of components.
  2570 
  2571 
  2572 *** HOL-Complex ***
  2573 
  2574 * Hyperreal: Functions root and sqrt are now defined on negative real
  2575 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2576 Nonnegativity side conditions have been removed from many lemmas, so
  2577 that more subgoals may now be solved by simplification; potential
  2578 INCOMPATIBILITY.
  2579 
  2580 * Real: new type classes formalize real normed vector spaces and
  2581 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2582 and norm :: 'a => real.
  2583 
  2584 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2585 reals into other types. The overloaded constant Reals :: 'a set is now
  2586 defined as range of_real; potential INCOMPATIBILITY.
  2587 
  2588 * Real: proper support for ML code generation, including 'quickcheck'.
  2589 Reals are implemented as arbitrary precision rationals.
  2590 
  2591 * Hyperreal: Several constants that previously worked only for the
  2592 reals have been generalized, so they now work over arbitrary vector
  2593 spaces. Type annotations may need to be added in some cases; potential
  2594 INCOMPATIBILITY.
  2595 
  2596   Infinitesimal  :: ('a::real_normed_vector) star set
  2597   HFinite        :: ('a::real_normed_vector) star set
  2598   HInfinite      :: ('a::real_normed_vector) star set
  2599   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2600   monad          :: ('a::real_normed_vector) star => 'a star set
  2601   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2602   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2603   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2604   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2605   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2606   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2607   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2608   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2609   sgn            :: 'a::real_normed_vector => 'a
  2610   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2611 
  2612 * Complex: Some complex-specific constants are now abbreviations for
  2613 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2614 hnorm.  Other constants have been entirely removed in favor of the
  2615 polymorphic versions (INCOMPATIBILITY):
  2616 
  2617   approx        <-- capprox
  2618   HFinite       <-- CFinite
  2619   HInfinite     <-- CInfinite
  2620   Infinitesimal <-- CInfinitesimal
  2621   monad         <-- cmonad
  2622   galaxy        <-- cgalaxy
  2623   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2624   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2625   (ns)deriv     <-- (ns)cderiv
  2626 
  2627 
  2628 *** HOL-Algebra ***
  2629 
  2630 * Formalisation of ideals and the quotient construction over rings.
  2631 
  2632 * Order and lattice theory no longer based on records.
  2633 INCOMPATIBILITY.
  2634 
  2635 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2636 greatest_closed.  INCOMPATIBILITY.
  2637 
  2638 * Method algebra is now set up via an attribute.  For examples see
  2639 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2640 of algebraic structures.
  2641 
  2642 * Renamed theory CRing to Ring.
  2643 
  2644 
  2645 *** HOL-Nominal ***
  2646 
  2647 * Substantial, yet incomplete support for nominal datatypes (binding
  2648 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2649 src/HOL/Nominal/Examples.  Prospective users should consult
  2650 http://isabelle.in.tum.de/nominal/
  2651 
  2652 
  2653 *** ML ***
  2654 
  2655 * ML basics: just one true type int, which coincides with IntInf.int
  2656 (even on SML/NJ).
  2657 
  2658 * ML within Isar: antiquotations allow to embed statically-checked
  2659 formal entities in the source, referring to the context available at
  2660 compile-time.  For example:
  2661 
  2662 ML {* @{sort "{zero,one}"} *}
  2663 ML {* @{typ "'a => 'b"} *}
  2664 ML {* @{term "%x. x"} *}
  2665 ML {* @{prop "x == y"} *}
  2666 ML {* @{ctyp "'a => 'b"} *}
  2667 ML {* @{cterm "%x. x"} *}
  2668 ML {* @{cprop "x == y"} *}
  2669 ML {* @{thm asm_rl} *}
  2670 ML {* @{thms asm_rl} *}
  2671 ML {* @{type_name c} *}
  2672 ML {* @{type_syntax c} *}
  2673 ML {* @{const_name c} *}
  2674 ML {* @{const_syntax c} *}
  2675 ML {* @{context} *}
  2676 ML {* @{theory} *}
  2677 ML {* @{theory Pure} *}
  2678 ML {* @{theory_ref} *}
  2679 ML {* @{theory_ref Pure} *}
  2680 ML {* @{simpset} *}
  2681 ML {* @{claset} *}
  2682 ML {* @{clasimpset} *}
  2683 
  2684 The same works for sources being ``used'' within an Isar context.
  2685 
  2686 * ML in Isar: improved error reporting; extra verbosity with
  2687 ML_Context.trace enabled.
  2688 
  2689 * Pure/General/table.ML: the join operations now works via exceptions
  2690 DUP/SAME instead of type option. This is simpler in simple cases, and
  2691 admits slightly more efficient complex applications.
  2692 
  2693 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2694 use Context.generic instead of just theory.
  2695 
  2696 * Pure: datatype Context.generic joins theory/Proof.context and
  2697 provides some facilities for code that works in either kind of
  2698 context, notably GenericDataFun for uniform theory and proof data.
  2699 
  2700 * Pure: simplified internal attribute type, which is now always
  2701 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2702 local (Proof.context) attributes have been discontinued, while
  2703 minimizing code duplication. Thm.rule_attribute and
  2704 Thm.declaration_attribute build canonical attributes; see also structure
  2705 Context for further operations on Context.generic, notably
  2706 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2707 declarations and definitions.
  2708 
  2709 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2710 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2711 init only required for impure data. INCOMPATIBILITY: empty really need
  2712 to be empty (no dependencies on theory content!)
  2713 
  2714 * Pure/kernel: consts certification ignores sort constraints given in
  2715 signature declarations. (This information is not relevant to the
  2716 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2717 potential INCOMPATIBILITY.
  2718 
  2719 * Pure: axiomatic type classes are now purely definitional, with
  2720 explicit proofs of class axioms and super class relations performed
  2721 internally. See Pure/axclass.ML for the main internal interfaces --
  2722 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2723 AxClass.axiomatize_class/classrel/arity supersede
  2724 Sign.add_classes/classrel/arities.
  2725 
  2726 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2727 global/local versions on theory vs. Proof.context have been
  2728 discontinued; Attrib.syntax and Method.syntax have been adapted
  2729 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2730 attributes, methods, etc.
  2731 
  2732 * Pure: several functions of signature "... -> theory -> theory * ..."
  2733 have been reoriented to "... -> theory -> ... * theory" in order to
  2734 allow natural usage in combination with the ||>, ||>>, |-> and
  2735 fold_map combinators.
  2736 
  2737 * Pure: official theorem names (closed derivations) and additional
  2738 comments (tags) are now strictly separate.  Name hints -- which are
  2739 maintained as tags -- may be attached any time without affecting the
  2740 derivation.
  2741 
  2742 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2743 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2744 achieve the old behaviour.
  2745 
  2746 * Pure: the "Goal" constant is now called "prop", supporting a
  2747 slightly more general idea of ``protecting'' meta-level rule
  2748 statements.
  2749 
  2750 * Pure: Logic.(un)varify only works in a global context, which is now
  2751 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2752 Logic.legacy_(un)varify as temporary workaround.
  2753 
  2754 * Pure: structure Name provides scalable operations for generating
  2755 internal variable names, notably Name.variants etc.  This replaces
  2756 some popular functions from term.ML:
  2757 
  2758   Term.variant		->  Name.variant
  2759   Term.variantlist	->  Name.variant_list
  2760   Term.invent_names	->  Name.invent_list
  2761 
  2762 Note that low-level renaming rarely occurs in new code -- operations
  2763 from structure Variable are used instead (see below).
  2764 
  2765 * Pure: structure Variable provides fundamental operations for proper
  2766 treatment of fixed/schematic variables in a context.  For example,
  2767 Variable.import introduces fixes for schematics of given facts and
  2768 Variable.export reverses the effect (up to renaming) -- this replaces
  2769 various freeze_thaw operations.
  2770 
  2771 * Pure: structure Goal provides simple interfaces for
  2772 init/conclude/finish and tactical prove operations (replacing former
  2773 Tactic.prove).  Goal.prove is the canonical way to prove results
  2774 within a given context; Goal.prove_global is a degraded version for
  2775 theory level goals, including a global Drule.standard.  Note that
  2776 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2777 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2778 in a locale context).
  2779 
  2780 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2781 and type checking (Syntax.check_term etc.), with common combinations
  2782 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2783 which are considered legacy and await removal.
  2784 
  2785 * Pure/Syntax: generic interfaces for type unchecking
  2786 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2787 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2788 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2789 available for convenience, but refer to the very same operations using
  2790 a mere theory instead of a full context.
  2791 
  2792 * Isar: simplified treatment of user-level errors, using exception
  2793 ERROR of string uniformly.  Function error now merely raises ERROR,
  2794 without any side effect on output channels.  The Isar toplevel takes
  2795 care of proper display of ERROR exceptions.  ML code may use plain
  2796 handle/can/try; cat_error may be used to concatenate errors like this:
  2797 
  2798   ... handle ERROR msg => cat_error msg "..."
  2799 
  2800 Toplevel ML code (run directly or through the Isar toplevel) may be
  2801 embedded into the Isar toplevel with exception display/debug like
  2802 this:
  2803 
  2804   Isar.toplevel (fn () => ...)
  2805 
  2806 INCOMPATIBILITY, removed special transform_error facilities, removed
  2807 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2808 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2809 -- use plain ERROR instead.
  2810 
  2811 * Isar: theory setup now has type (theory -> theory), instead of a
  2812 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2813 
  2814 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2815 ProofContext.debug/verbose flags.
  2816 
  2817 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2818 theory before entering a proof state.  Transactions now always see a
  2819 quasi-functional intermediate checkpoint, both in interactive and
  2820 batch mode.
  2821 
  2822 * Isar: simplified interfaces for outer syntax.  Renamed
  2823 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2824 OuterSyntax.add_parsers -- this functionality is now included in
  2825 OuterSyntax.command etc.  INCOMPATIBILITY.
  2826 
  2827 * Simplifier: the simpset of a running simplification process now
  2828 contains a proof context (cf. Simplifier.the_context), which is the
  2829 very context that the initial simpset has been retrieved from (by
  2830 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2831 (solver, looper etc.) may depend on arbitrary proof data.
  2832 
  2833 * Simplifier.inherit_context inherits the proof context (plus the
  2834 local bounds) of the current simplification process; any simproc
  2835 etc. that calls the Simplifier recursively should do this!  Removed
  2836 former Simplifier.inherit_bounds, which is already included here --
  2837 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2838 specify an explicit context using Simplifier.context/theory_context.
  2839 
  2840 * Simplifier/Classical Reasoner: more abstract interfaces
  2841 change_simpset/claset for modifying the simpset/claset reference of a
  2842 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2843 INCOMPATIBILITY.
  2844 
  2845 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2846 "Trueprop" etc.
  2847 
  2848 
  2849 *** System ***
  2850 
  2851 * settings: the default heap location within ISABELLE_HOME_USER now
  2852 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2853 Isabelle installations.
  2854 
  2855 * isabelle-process: option -S (secure mode) disables some critical
  2856 operations, notably runtime compilation and evaluation of ML source
  2857 code.
  2858 
  2859 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2860 
  2861 * Support for parallel execution, using native multicore support of
  2862 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2863 independent theories, according to the given theory header
  2864 specifications. The maximum number of worker threads is specified via
  2865 usedir option -M or the "max-threads" setting in Proof General. A
  2866 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2867 to 6 on a 8-core machine.  User-code needs to observe certain
  2868 guidelines for thread-safe programming, see appendix A in the Isar
  2869 Implementation manual.
  2870 
  2871 
  2872 
  2873 New in Isabelle2005 (October 2005)
  2874 ----------------------------------
  2875 
  2876 *** General ***
  2877 
  2878 * Theory headers: the new header syntax for Isar theories is
  2879 
  2880   theory <name>
  2881   imports <theory1> ... <theoryN>
  2882   uses <file1> ... <fileM>
  2883   begin
  2884 
  2885 where the 'uses' part is optional.  The previous syntax
  2886 
  2887   theory <name> = <theory1> + ... + <theoryN>:
  2888 
  2889 will disappear in the next release.  Use isatool fixheaders to convert
  2890 existing theory files.  Note that there is no change in ancient
  2891 non-Isar theories now, but these will disappear soon.
  2892 
  2893 * Theory loader: parent theories can now also be referred to via
  2894 relative and absolute paths.
  2895 
  2896 * Command 'find_theorems' searches for a list of criteria instead of a
  2897 list of constants. Known criteria are: intro, elim, dest, name:string,
  2898 simp:term, and any term. Criteria can be preceded by '-' to select
  2899 theorems that do not match. Intro, elim, dest select theorems that
  2900 match the current goal, name:s selects theorems whose fully qualified
  2901 name contain s, and simp:term selects all simplification rules whose
  2902 lhs match term.  Any other term is interpreted as pattern and selects
  2903 all theorems matching the pattern. Available in ProofGeneral under
  2904 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2905 
  2906   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2907 
  2908 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2909 matching the current goal as introduction rule and not having "HOL."
  2910 in their name (i.e. not being defined in theory HOL).
  2911 
  2912 * Command 'thms_containing' has been discontinued in favour of
  2913 'find_theorems'; INCOMPATIBILITY.
  2914 
  2915 * Communication with Proof General is now 8bit clean, which means that
  2916 Unicode text in UTF-8 encoding may be used within theory texts (both
  2917 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2918 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2919 
  2920   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2921   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2922 
  2923 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2924 Classical Reasoner.  Typical big applications run around 2 times
  2925 faster.
  2926 
  2927 
  2928 *** Document preparation ***
  2929 
  2930 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2931 of raw sources.  Only those symbols that do not require additional
  2932 LaTeX packages (depending on comments in isabellesym.sty) are
  2933 displayed properly, everything else is left verbatim.  isatool display
  2934 and isatool print are used as front ends (these are subject to the
  2935 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2936 
  2937 * Command tags control specific markup of certain regions of text,
  2938 notably folding and hiding.  Predefined tags include "theory" (for
  2939 theory begin and end), "proof" for proof commands, and "ML" for
  2940 commands involving ML code; the additional tags "visible" and
  2941 "invisible" are unused by default.  Users may give explicit tag
  2942 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2943 interpretation of tags is determined by the LaTeX job during document
  2944 preparation: see option -V of isatool usedir, or options -n and -t of
  2945 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2946 \isadroptag.
  2947 
  2948 Several document versions may be produced at the same time via isatool
  2949 usedir (the generated index.html will link all of them).  Typical
  2950 specifications include ''-V document=theory,proof,ML'' to present
  2951 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2952 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2953 these parts without any formal replacement text.  The Isabelle site
  2954 default settings produce ''document'' and ''outline'' versions as
  2955 specified above.
  2956 
  2957 * Several new antiquotations:
  2958 
  2959   @{term_type term} prints a term with its type annotated;
  2960 
  2961   @{typeof term} prints the type of a term;
  2962 
  2963   @{const const} is the same as @{term const}, but checks that the
  2964   argument is a known logical constant;
  2965 
  2966   @{term_style style term} and @{thm_style style thm} print a term or
  2967   theorem applying a "style" to it
  2968 
  2969   @{ML text}
  2970 
  2971 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2972 definitions, equations, inequations etc., 'concl' printing only the
  2973 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2974 to print the specified premise.  TermStyle.add_style provides an ML
  2975 interface for introducing further styles.  See also the "LaTeX Sugar"
  2976 document practical applications.  The ML antiquotation prints
  2977 type-checked ML expressions verbatim.
  2978 
  2979 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2980 and 'text' support optional locale specification '(in loc)', which
  2981 specifies the default context for interpreting antiquotations.  For
  2982 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2983 
  2984 * Option 'locale=NAME' of antiquotations specifies an alternative
  2985 context interpreting the subsequent argument.  For example: @{thm
  2986 [locale=lattice] inf_assoc}.
  2987 
  2988 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2989 a proof context.
  2990 
  2991 * Proper output of antiquotations for theory commands involving a
  2992 proof context (such as 'locale' or 'theorem (in loc) ...').
  2993 
  2994 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2995 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2996 
  2997 * isatool usedir: new option -C (default true) controls whether option
  2998 -D should include a copy of the original document directory; -C false
  2999 prevents unwanted effects such as copying of administrative CVS data.
  3000 
  3001 
  3002 *** Pure ***
  3003 
  3004 * Considerably improved version of 'constdefs' command.  Now performs
  3005 automatic type-inference of declared constants; additional support for
  3006 local structure declarations (cf. locales and HOL records), see also
  3007 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3008 sequential dependencies of definitions within a single 'constdefs'
  3009 section; moreover, the declared name needs to be an identifier.  If
  3010 all fails, consider to fall back on 'consts' and 'defs' separately.
  3011 
  3012 * Improved indexed syntax and implicit structures.  First of all,
  3013 indexed syntax provides a notational device for subscripted
  3014 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3015 expressions.  Secondly, in a local context with structure
  3016 declarations, number indexes \<^sub>n or the empty index (default
  3017 number 1) refer to a certain fixed variable implicitly; option
  3018 show_structs controls printing of implicit structures.  Typical
  3019 applications of these concepts involve record types and locales.
  3020 
  3021 * New command 'no_syntax' removes grammar declarations (and
  3022 translations) resulting from the given syntax specification, which is
  3023 interpreted in the same manner as for the 'syntax' command.
  3024 
  3025 * 'Advanced' translation functions (parse_translation etc.) may depend
  3026 on the signature of the theory context being presently used for
  3027 parsing/printing, see also isar-ref manual.
  3028 
  3029 * Improved 'oracle' command provides a type-safe interface to turn an
  3030 ML expression of type theory -> T -> term into a primitive rule of
  3031 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3032 is already included here); see also FOL/ex/IffExample.thy;
  3033 INCOMPATIBILITY.
  3034 
  3035 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3036 before); "cI" is no longer bound, use "c.intro" instead.
  3037 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3038 axclasses vs. locales.
  3039 
  3040 * Improved internal renaming of symbolic identifiers -- attach primes
  3041 instead of base 26 numbers.
  3042 
  3043 * New flag show_question_marks controls printing of leading question
  3044 marks in schematic variable names.
  3045 
  3046 * In schematic variable names, *any* symbol following \<^isub> or
  3047 \<^isup> is now treated as part of the base name.  For example, the
  3048 following works without printing of awkward ".0" indexes:
  3049 
  3050   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3051     by simp
  3052 
  3053 * Inner syntax includes (*(*nested*) comments*).
  3054 
  3055 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3056 annotations as "(00...)".
  3057 
  3058 * Clear separation of logical types and nonterminals, where the latter
  3059 may only occur in 'syntax' specifications or type abbreviations.
  3060 Before that distinction was only partially implemented via type class
  3061 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3062 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3063 exotic syntax specifications may require further adaption
  3064 (e.g. Cube/Cube.thy).
  3065 
  3066 * Removed obsolete type class "logic", use the top sort {} instead.
  3067 Note that non-logical types should be declared as 'nonterminals'
  3068 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3069 specifications.
  3070 
  3071 * Attributes 'induct' and 'cases': type or set names may now be
  3072 locally fixed variables as well.
  3073 
  3074 * Simplifier: can now control the depth to which conditional rewriting
  3075 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3076 Limit.
  3077 
  3078 * Simplifier: simplification procedures may now take the current
  3079 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3080 interface), which is very useful for calling the Simplifier
  3081 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3082 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3083 low-level mk_simproc no longer applies Logic.varify internally, to
  3084 allow for use in a context of fixed variables.
  3085 
  3086 * thin_tac now works even if the assumption being deleted contains !!
  3087 or ==>.  More generally, erule now works even if the major premise of
  3088 the elimination rule contains !! or ==>.
  3089 
  3090 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3091 
  3092 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3093 from Pure, which contains all common declarations already.  Both
  3094 theories are defined via plain Isabelle/Isar .thy files.
  3095 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3096 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3097 use isatool fixcpure to adapt your theory and ML sources.
  3098 
  3099 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3100 selections of theorems in named facts via index ranges.
  3101 
  3102 * 'print_theorems': in theory mode, really print the difference
  3103 wrt. the last state (works for interactive theory development only),
  3104 in proof mode print all local facts (cf. 'print_facts');
  3105 
  3106 * 'hide': option '(open)' hides only base names.
  3107 
  3108 * More efficient treatment of intermediate checkpoints in interactive
  3109 theory development.
  3110 
  3111 * Code generator is now invoked via code_module (incremental code
  3112 generation) and code_library (modular code generation, ML structures
  3113 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3114 must be quoted when used as identifiers.
  3115 
  3116 * New 'value' command for reading, evaluating and printing terms using
  3117 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3118 quoted when used as identifier.
  3119 
  3120 
  3121 *** Locales ***
  3122 
  3123 * New commands for the interpretation of locale expressions in
  3124 theories (1), locales (2) and proof contexts (3).  These generate
  3125 proof obligations from the expression specification.  After the
  3126 obligations have been discharged, theorems of the expression are added
  3127 to the theory, target locale or proof context.  The synopsis of the
  3128 commands is a follows:
  3129 
  3130   (1) interpretation expr inst
  3131   (2) interpretation target < expr
  3132   (3) interpret expr inst
  3133 
  3134 Interpretation in theories and proof contexts require a parameter
  3135 instantiation of terms from the current context.  This is applied to
  3136 specifications and theorems of the interpreted expression.
  3137 Interpretation in locales only permits parameter renaming through the
  3138 locale expression.  Interpretation is smart in that interpretations
  3139 that are active already do not occur in proof obligations, neither are
  3140 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3141 inspect active interpretations of a particular locale.  For details,
  3142 see the Isar Reference manual.  Examples can be found in
  3143 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3144 
  3145 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3146 'interpret' instead.
  3147 
  3148 * New context element 'constrains' for adding type constraints to
  3149 parameters.
  3150 
  3151 * Context expressions: renaming of parameters with syntax
  3152 redeclaration.
  3153 
  3154 * Locale declaration: 'includes' disallowed.
  3155 
  3156 * Proper static binding of attribute syntax -- i.e. types / terms /
  3157 facts mentioned as arguments are always those of the locale definition
  3158 context, independently of the context of later invocations.  Moreover,
  3159 locale operations (renaming and type / term instantiation) are applied
  3160 to attribute arguments as expected.
  3161 
  3162 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3163 actual attributes; rare situations may require Attrib.attribute to
  3164 embed those attributes into Attrib.src that lack concrete syntax.
  3165 Attribute implementations need to cooperate properly with the static
  3166 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3167 Attrib.XXX_thm etc. already do the right thing without further
  3168 intervention.  Only unusual applications -- such as "where" or "of"
  3169 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3170 on the context and the facts involved -- may have to assign parsed
  3171 values to argument tokens explicitly.
  3172 
  3173 * Changed parameter management in theorem generation for long goal
  3174 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3175 theorem statement in rare situations.
  3176 
  3177 * Locale inspection command 'print_locale' omits notes elements.  Use
  3178 'print_locale!' to have them included in the output.
  3179 
  3180 
  3181 *** Provers ***
  3182 
  3183 * Provers/hypsubst.ML: improved version of the subst method, for
  3184 single-step rewriting: it now works in bound variable contexts. New is
  3185 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3186 rewrite a different subterm than the original subst method, which is
  3187 still available as 'simplesubst'.
  3188 
  3189 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3190 and quasi orders.
  3191 
  3192 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3193 reflexive-transitive closure of relations.
  3194 
  3195 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3196 limit (previously hard-coded with a value of 20) user-definable.
  3197 
  3198 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3199 is peformed already.  Object-logics merely need to finish their
  3200 initial simpset configuration as before.  INCOMPATIBILITY.
  3201 
  3202 
  3203 *** HOL ***
  3204 
  3205 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3206 
  3207   syntax (epsilon)
  3208     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3209 
  3210 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3211 and x-symbol; use option '-m epsilon' to get it actually printed.
  3212 Moreover, the mathematically important symbolic identifier \<epsilon>
  3213 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3214 
  3215 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3216 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3217 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3218 support corresponding Isar calculations.
  3219 
  3220 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3221 instead of ":".
  3222 
  3223 * theory SetInterval: changed the syntax for open intervals:
  3224 
  3225   Old       New
  3226   {..n(}    {..<n}
  3227   {)n..}    {n<..}
  3228   {m..n(}   {m..<n}
  3229   {)m..n}   {m<..n}
  3230   {)m..n(}  {m<..<n}
  3231 
  3232 The old syntax is still supported but will disappear in the next
  3233 release.  For conversion use the following Emacs search and replace
  3234 patterns (these are not perfect but work quite well):
  3235 
  3236   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3237   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3238 
  3239 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3240 equalities in commutative rings; method 'algebra' provides a generic
  3241 interface.
  3242 
  3243 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3244 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3245 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3246 be a tuple pattern.
  3247 
  3248 Some new syntax forms are available:
  3249 
  3250   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3251   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3252   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3253   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3254 
  3255 The latter form "\<Sum>x < k. e" used to be based on a separate
  3256 function "Summation", which has been discontinued.
  3257 
  3258 * theory Finite_Set: in structured induction proofs, the insert case
  3259 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3260 (insert F x)'.
  3261 
  3262 * The 'refute' command has been extended to support a much larger
  3263 fragment of HOL, including axiomatic type classes, constdefs and
  3264 typedefs, inductive datatypes and recursion.
  3265 
  3266 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3267 Requires zChaff with proof generation to be installed.  See
  3268 HOL/ex/SAT_Examples.thy for examples.
  3269 
  3270 * Datatype induction via method 'induct' now preserves the name of the
  3271 induction variable. For example, when proving P(xs::'a list) by
  3272 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3273 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3274 in unstructured proof scripts.
  3275 
  3276 * Reworked implementation of records.  Improved scalability for
  3277 records with many fields, avoiding performance problems for type
  3278 inference. Records are no longer composed of nested field types, but
  3279 of nested extension types. Therefore the record type only grows linear
  3280 in the number of extensions and not in the number of fields.  The
  3281 top-level (users) view on records is preserved.  Potential
  3282 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3283 old record representation. The type generated for a record is called
  3284 <record_name>_ext_type.
  3285 
  3286 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3287 proofs triggered by a record definition or a simproc (if
  3288 quick_and_dirty is enabled).  Definitions of large records can take
  3289 quite long.
  3290 
  3291 New simproc record_upd_simproc for simplification of multiple record
  3292 updates enabled by default.  Moreover, trivial updates are also
  3293 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3294 occasionally, since simplification is more powerful by default.
  3295 
  3296 * typedef: proper support for polymorphic sets, which contain extra
  3297 type-variables in the term.
  3298 
  3299 * Simplifier: automatically reasons about transitivity chains
  3300 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3301 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3302 old proofs break occasionally as simplification may now solve more
  3303 goals than previously.
  3304 
  3305 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3306 present.  Works for all partial orders (class "order"), in particular
  3307 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3308 just like y <= x.
  3309 
  3310 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3311 bound variable or a constant then the let is unfolded.  Otherwise
  3312 first a is simplified to b, and then f b is simplified to g. If
  3313 possible we abstract b from g arriving at "let x = b in h x",
  3314 otherwise we unfold the let and arrive at g.  The simproc can be
  3315 enabled/disabled by the reference use_let_simproc.  Potential
  3316 INCOMPATIBILITY since simplification is more powerful by default.
  3317 
  3318 * Classical reasoning: the meson method now accepts theorems as arguments.
  3319 
  3320 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3321 jobs to provide advice on the provability of subgoals.
  3322 
  3323 * Theory OrderedGroup and Ring_and_Field: various additions and
  3324 improvements to faciliate calculations involving equalities and
  3325 inequalities.
  3326 
  3327 The following theorems have been eliminated or modified
  3328 (INCOMPATIBILITY):
  3329 
  3330   abs_eq             now named abs_of_nonneg
  3331   abs_of_ge_0        now named abs_of_nonneg
  3332   abs_minus_eq       now named abs_of_nonpos
  3333   imp_abs_id         now named abs_of_nonneg
  3334   imp_abs_neg_id     now named abs_of_nonpos
  3335   mult_pos           now named mult_pos_pos
  3336   mult_pos_le        now named mult_nonneg_nonneg
  3337   mult_pos_neg_le    now named mult_nonneg_nonpos
  3338   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3339   mult_neg           now named mult_neg_neg
  3340   mult_neg_le        now named mult_nonpos_nonpos
  3341 
  3342 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3343      
  3344      zero_le_square
  3345      not_square_less_zero 
  3346 
  3347   The following lemmas have been deleted from Real/RealPow:
  3348   
  3349      realpow_zero_zero
  3350      realpow_two
  3351      realpow_less
  3352      zero_le_power
  3353      realpow_two_le
  3354      abs_realpow_two
  3355      realpow_two_abs     
  3356 
  3357 * Theory Parity: added rules for simplifying exponents.
  3358 
  3359 * Theory List:
  3360 
  3361 The following theorems have been eliminated or modified
  3362 (INCOMPATIBILITY):
  3363 
  3364   list_all_Nil       now named list_all.simps(1)
  3365   list_all_Cons      now named list_all.simps(2)
  3366   list_all_conv      now named list_all_iff
  3367   set_mem_eq         now named mem_iff
  3368 
  3369 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3370 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3371 
  3372 
  3373 *** HOL-Complex ***
  3374 
  3375 * Theory RealDef: better support for embedding natural numbers and
  3376 integers in the reals.
  3377 
  3378 The following theorems have been eliminated or modified
  3379 (INCOMPATIBILITY):
  3380 
  3381   exp_ge_add_one_self  now requires no hypotheses
  3382   real_of_int_add      reversed direction of equality (use [symmetric])
  3383   real_of_int_minus    reversed direction of equality (use [symmetric])
  3384   real_of_int_diff     reversed direction of equality (use [symmetric])
  3385   real_of_int_mult     reversed direction of equality (use [symmetric])
  3386 
  3387 * Theory RComplete: expanded support for floor and ceiling functions.
  3388 
  3389 * Theory Ln is new, with properties of the natural logarithm
  3390 
  3391 * Hyperreal: There is a new type constructor "star" for making
  3392 nonstandard types.  The old type names are now type synonyms:
  3393 
  3394   hypreal = real star
  3395   hypnat = nat star
  3396   hcomplex = complex star
  3397 
  3398 * Hyperreal: Many groups of similarly-defined constants have been
  3399 replaced by polymorphic versions (INCOMPATIBILITY):
  3400 
  3401   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3402 
  3403   starset      <-- starsetNat, starsetC
  3404   *s*          <-- *sNat*, *sc*
  3405   starset_n    <-- starsetNat_n, starsetC_n
  3406   *sn*         <-- *sNatn*, *scn*
  3407   InternalSets <-- InternalNatSets, InternalCSets
  3408 
  3409   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3410   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3411   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3412   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3413   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3414 
  3415 * Hyperreal: Many type-specific theorems have been removed in favor of
  3416 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3417 
  3418   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3419   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3420   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3421   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3422   right_minus <-- hypreal_add_minus
  3423   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3424   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3425   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3426   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3427   mult_1_right <-- hcomplex_mult_one_right
  3428   mult_zero_left <-- hcomplex_mult_zero_left
  3429   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3430   right_distrib <-- hypnat_add_mult_distrib2
  3431   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3432   right_inverse <-- hypreal_mult_inverse
  3433   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3434   order_refl <-- {hypreal,hypnat}_le_refl
  3435   order_trans <-- {hypreal,hypnat}_le_trans
  3436   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3437   order_less_le <-- {hypreal,hypnat}_less_le
  3438   linorder_linear <-- {hypreal,hypnat}_le_linear
  3439   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3440   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3441   add_nonneg_nonneg <-- hypreal_le_add_order
  3442 
  3443 * Hyperreal: Separate theorems having to do with type-specific
  3444 versions of constants have been merged into theorems that apply to the
  3445 new polymorphic constants (INCOMPATIBILITY):
  3446 
  3447   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3448   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3449   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3450   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3451   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3452   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3453   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3454   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3455   STAR_diff <-- {STAR,STARC}_diff
  3456   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3457     STARC_hcomplex_of_complex}_image_subset
  3458   starset_n_Un <-- starset{Nat,C}_n_Un
  3459   starset_n_Int <-- starset{Nat,C}_n_Int
  3460   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3461   starset_n_diff <-- starset{Nat,C}_n_diff
  3462   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3463   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3464   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3465   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3466   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3467   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3468   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3469   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3470   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3471   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3472   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3473   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3474   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3475   starfun_diff <-- starfun{C,RC,CR}_diff
  3476   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3477   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3478   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3479   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3480   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3481   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3482   starfun_Id <-- starfunC_Id
  3483   starfun_approx <-- starfun{Nat,CR}_approx
  3484   starfun_capprox <-- starfun{C,RC}_capprox
  3485   starfun_abs <-- starfunNat_rabs
  3486   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3487   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3488   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3489   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3490   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3491   starfun_add_approx <-- starfunCR_add_approx
  3492   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3493   starfun_divide <-- starfun{C,CR,RC}_divide
  3494   starfun_n <-- starfun{Nat,C}_n
  3495   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3496   starfun_n_add <-- starfun{Nat,C}_n_add
  3497   starfun_n_add_minus <-- starfunNat_n_add_minus
  3498   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3499   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3500   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3501 
  3502   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3503   star_n_minus <-- {hypreal,hcomplex}_minus
  3504   star_n_diff <-- {hypreal,hcomplex}_diff
  3505   star_n_mult <-- {hypreal,hcomplex}_mult
  3506   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3507   star_n_le <-- {hypreal,hypnat}_le
  3508   star_n_less <-- {hypreal,hypnat}_less
  3509   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3510   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3511   star_n_abs <-- hypreal_hrabs
  3512   star_n_divide <-- hcomplex_divide
  3513 
  3514   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3515   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3516   star_of_diff <-- hypreal_of_real_diff
  3517   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3518   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3519   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3520   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3521   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3522   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3523   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3524   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3525   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3526   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3527   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3528   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3529   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3530   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3531   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3532   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3533   star_of_power <-- hypreal_of_real_power
  3534   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3535 
  3536 * Hyperreal: new method "transfer" that implements the transfer
  3537 principle of nonstandard analysis. With a subgoal that mentions
  3538 nonstandard types like "'a star", the command "apply transfer"
  3539 replaces it with an equivalent one that mentions only standard types.
  3540 To be successful, all free variables must have standard types; non-
  3541 standard variables must have explicit universal quantifiers.
  3542 
  3543 * Hyperreal: A theory of Taylor series.
  3544 
  3545 
  3546 *** HOLCF ***
  3547 
  3548 * Discontinued special version of 'constdefs' (which used to support
  3549 continuous functions) in favor of the general Pure one with full
  3550 type-inference.
  3551 
  3552 * New simplification procedure for solving continuity conditions; it
  3553 is much faster on terms with many nested lambda abstractions (cubic
  3554 instead of exponential time).
  3555 
  3556 * New syntax for domain package: selector names are now optional.
  3557 Parentheses should be omitted unless argument is lazy, for example:
  3558 
  3559   domain 'a stream = cons "'a" (lazy "'a stream")
  3560 
  3561 * New command 'fixrec' for defining recursive functions with pattern
  3562 matching; defining multiple functions with mutual recursion is also
  3563 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3564 sinr, or any data constructor defined by the domain package. The given
  3565 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3566 syntax and examples.
  3567 
  3568 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3569 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3570 but the proof obligation additionally includes an admissibility
  3571 requirement. The packages generate instances of class cpo or pcpo,
  3572 with continuity and strictness theorems for Rep and Abs.
  3573 
  3574 * HOLCF: Many theorems have been renamed according to a more standard naming
  3575 scheme (INCOMPATIBILITY):
  3576 
  3577   foo_inject:  "foo$x = foo$y ==> x = y"
  3578   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3579   foo_less:    "(foo$x << foo$y) = (x << y)"
  3580   foo_strict:  "foo$UU = UU"
  3581   foo_defined: "... ==> foo$x ~= UU"
  3582   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3583 
  3584 
  3585 *** ZF ***
  3586 
  3587 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3588 including the First Isomorphism Theorem (on quotienting by the kernel
  3589 of a homomorphism).
  3590 
  3591 * ZF/Simplifier: install second copy of type solver that actually
  3592 makes use of TC rules declared to Isar proof contexts (or locales);
  3593 the old version is still required for ML proof scripts.
  3594 
  3595 
  3596 *** Cube ***
  3597 
  3598 * Converted to Isar theory format; use locales instead of axiomatic
  3599 theories.
  3600 
  3601 
  3602 *** ML ***
  3603 
  3604 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3605 for ||>, ||>>, |>>,
  3606 
  3607 * Pure/library.ML no longer defines its own option datatype, but uses
  3608 that of the SML basis, which has constructors NONE and SOME instead of
  3609 None and Some, as well as exception Option.Option instead of OPTION.
  3610 The functions the, if_none, is_some, is_none have been adapted
  3611 accordingly, while Option.map replaces apsome.
  3612 
  3613 * Pure/library.ML: the exception LIST has been given up in favour of
  3614 the standard exceptions Empty and Subscript, as well as
  3615 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3616 superceded by the standard hd and tl functions etc.
  3617 
  3618 A number of basic list functions are no longer exported to the ML
  3619 toplevel, as they are variants of predefined functions.  The following
  3620 suggests how one can translate existing code:
  3621 
  3622     rev_append xs ys = List.revAppend (xs, ys)
  3623     nth_elem (i, xs) = List.nth (xs, i)
  3624     last_elem xs = List.last xs
  3625     flat xss = List.concat xss
  3626     seq fs = List.app fs
  3627     partition P xs = List.partition P xs
  3628     mapfilter f xs = List.mapPartial f xs
  3629 
  3630 * Pure/library.ML: several combinators for linear functional
  3631 transformations, notably reverse application and composition:
  3632 
  3633   x |> f                f #> g
  3634   (x, y) |-> f          f #-> g
  3635 
  3636 * Pure/library.ML: introduced/changed precedence of infix operators:
  3637 
  3638   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3639   infix 2 ?;
  3640   infix 3 o oo ooo oooo;
  3641   infix 4 ~~ upto downto;
  3642 
  3643 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3644 infix operators.
  3645 
  3646 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3647 fold_map support linear functional transformations and nesting.  For
  3648 example:
  3649 
  3650   fold f [x1, ..., xN] y =
  3651     y |> f x1 |> ... |> f xN
  3652 
  3653   (fold o fold) f [xs1, ..., xsN] y =
  3654     y |> fold f xs1 |> ... |> fold f xsN
  3655 
  3656   fold f [x1, ..., xN] =
  3657     f x1 #> ... #> f xN
  3658 
  3659   (fold o fold) f [xs1, ..., xsN] =
  3660     fold f xs1 #> ... #> fold f xsN
  3661 
  3662 * Pure/library.ML: the following selectors on type 'a option are
  3663 available:
  3664 
  3665   the:               'a option -> 'a  (*partial*)
  3666   these:             'a option -> 'a  where 'a = 'b list
  3667   the_default: 'a -> 'a option -> 'a
  3668   the_list:          'a option -> 'a list
  3669 
  3670 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3671 basic operations for association lists, following natural argument
  3672 order; moreover the explicit equality predicate passed here avoids
  3673 potentially expensive polymorphic runtime equality checks.
  3674 The old functions may be expressed as follows:
  3675 
  3676   assoc = uncurry (AList.lookup (op =))
  3677   assocs = these oo AList.lookup (op =)
  3678   overwrite = uncurry (AList.update (op =)) o swap
  3679 
  3680 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3681 
  3682   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3683   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3684 
  3685 replacing make_keylist and keyfilter (occassionally used)
  3686 Naive rewrites:
  3687 
  3688   make_keylist = AList.make
  3689   keyfilter = AList.find (op =)
  3690 
  3691 * eq_fst and eq_snd now take explicit equality parameter, thus
  3692   avoiding eqtypes. Naive rewrites:
  3693 
  3694     eq_fst = eq_fst (op =)
  3695     eq_snd = eq_snd (op =)
  3696 
  3697 * Removed deprecated apl and apr (rarely used).
  3698   Naive rewrites:
  3699 
  3700     apl (n, op) =>>= curry op n
  3701     apr (op, m) =>>= fn n => op (n, m)
  3702 
  3703 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3704 provides a reasonably efficient light-weight implementation of sets as
  3705 lists.
  3706 
  3707 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3708 few new operations; existing lookup and update are now curried to
  3709 follow natural argument order (for use with fold etc.);
  3710 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3711 
  3712 * Pure/General: output via the Isabelle channels of
  3713 writeln/warning/error etc. is now passed through Output.output, with a
  3714 hook for arbitrary transformations depending on the print_mode
  3715 (cf. Output.add_mode -- the first active mode that provides a output
  3716 function wins).  Already formatted output may be embedded into further
  3717 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3718 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3719 accommodate easy composition of diagnostic messages etc.  Programmers
  3720 rarely need to care about Output.output or Output.raw at all, with
  3721 some notable exceptions: Output.output is required when bypassing the
  3722 standard channels (writeln etc.), or in token translations to produce
  3723 properly formatted results; Output.raw is required when capturing
  3724 already output material that will eventually be presented to the user
  3725 a second time.  For the default print mode, both Output.output and
  3726 Output.raw have no effect.
  3727 
  3728 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3729 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3730 cumulative results are displayed at the end of a batch session.
  3731 
  3732 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3733 replaced by File.platform_path and File.shell_path (with appropriate
  3734 hooks).  This provides a clean interface for unusual systems where the
  3735 internal and external process view of file names are different.
  3736 
  3737 * Pure: more efficient orders for basic syntactic entities: added
  3738 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3739 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3740 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3741 orders now -- potential INCOMPATIBILITY for code that depends on a
  3742 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3743 Library.sort_strings on result).
  3744 
  3745 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3746 fold_types traverse types/terms from left to right, observing natural
  3747 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3748 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3749 
  3750 * Pure: name spaces have been refined, with significant changes of the
  3751 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3752 to extern(_table).  The plain name entry path is superceded by a
  3753 general 'naming' context, which also includes the 'policy' to produce
  3754 a fully qualified name and external accesses of a fully qualified
  3755 name; NameSpace.extend is superceded by context dependent
  3756 Sign.declare_name.  Several theory and proof context operations modify
  3757 the naming context.  Especially note Theory.restore_naming and
  3758 ProofContext.restore_naming to get back to a sane state; note that
  3759 Theory.add_path is no longer sufficient to recover from
  3760 Theory.absolute_path in particular.
  3761 
  3762 * Pure: new flags short_names (default false) and unique_names
  3763 (default true) for controlling output of qualified names.  If
  3764 short_names is set, names are printed unqualified.  If unique_names is
  3765 reset, the name prefix is reduced to the minimum required to achieve
  3766 the original result when interning again, even if there is an overlap
  3767 with earlier declarations.
  3768 
  3769 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3770 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3771 (useful for printing error messages).  INCOMPATIBILITY.
  3772 
  3773 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3774 Theory.theory are now identified, referring to the universal
  3775 Context.theory (see Pure/context.ML).  Actual signature and theory
  3776 content is managed as theory data.  The old code and interfaces were
  3777 spread over many files and structures; the new arrangement introduces
  3778 considerable INCOMPATIBILITY to gain more clarity:
  3779 
  3780   Context -- theory management operations (name, identity, inclusion,
  3781     parents, ancestors, merge, etc.), plus generic theory data;
  3782 
  3783   Sign -- logical signature and syntax operations (declaring consts,
  3784     types, etc.), plus certify/read for common entities;
  3785 
  3786   Theory -- logical theory operations (stating axioms, definitions,
  3787     oracles), plus a copy of logical signature operations (consts,
  3788     types, etc.); also a few basic management operations (Theory.copy,
  3789     Theory.merge, etc.)
  3790 
  3791 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3792 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3793 for convenience -- they merely return the theory.
  3794 
  3795 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3796 
  3797 * Pure: the Isar proof context type is already defined early in Pure
  3798 as Context.proof (note that ProofContext.context and Proof.context are
  3799 aliases, where the latter is the preferred name).  This enables other
  3800 Isabelle components to refer to that type even before Isar is present.
  3801 
  3802 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3803 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3804 any of these kinds.  For example, Sign.intern typeK is now
  3805 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3806 Theory.hide_types.  Also note that former
  3807 Theory.hide_classes/types/consts are now
  3808 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3809 internalize their arguments!  INCOMPATIBILITY.
  3810 
  3811 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3812 datatype thmref (with constructors Name and NameSelection) instead of
  3813 plain string -- INCOMPATIBILITY;
  3814 
  3815 * Pure: cases produced by proof methods specify options, where NONE
  3816 means to remove case bindings -- INCOMPATIBILITY in
  3817 (RAW_)METHOD_CASES.
  3818 
  3819 * Pure: the following operations retrieve axioms or theorems from a
  3820 theory node or theory hierarchy, respectively:
  3821 
  3822   Theory.axioms_of: theory -> (string * term) list
  3823   Theory.all_axioms_of: theory -> (string * term) list
  3824   PureThy.thms_of: theory -> (string * thm) list
  3825   PureThy.all_thms_of: theory -> (string * thm) list
  3826 
  3827 * Pure: print_tac now outputs the goal through the trace channel.
  3828 
  3829 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3830 Reference Toplevel.debug (default false) controls detailed printing
  3831 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3832 controls execution profiling -- set to 1 for time and 2 for space
  3833 (both increase the runtime).
  3834 
  3835 * Isar session: The initial use of ROOT.ML is now always timed,
  3836 i.e. the log will show the actual process times, in contrast to the
  3837 elapsed wall-clock time that the outer shell wrapper produces.
  3838 
  3839 * Simplifier: improved handling of bound variables (nameless
  3840 representation, avoid allocating new strings).  Simprocs that invoke
  3841 the Simplifier recursively should use Simplifier.inherit_bounds to
  3842 avoid local name clashes.  Failure to do so produces warnings
  3843 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3844 for further details.
  3845 
  3846 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3847 bindings for all theorems stored within a given theory; this may help
  3848 in porting non-Isar theories to Isar ones, while keeping ML proof
  3849 scripts for the time being.
  3850 
  3851 * ML operator HTML.with_charset specifies the charset begin used for
  3852 generated HTML files.  For example:
  3853 
  3854   HTML.with_charset "utf-8" use_thy "Hebrew";
  3855   HTML.with_charset "utf-8" use_thy "Chinese";
  3856 
  3857 
  3858 *** System ***
  3859 
  3860 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3861 isabelle, isatool etc.).
  3862 
  3863 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3864 isatool doc, isatool mkdir, display_drafts etc.).
  3865 
  3866 * isatool usedir: option -f allows specification of the ML file to be
  3867 used by Isabelle; default is ROOT.ML.
  3868 
  3869 * New isatool version outputs the version identifier of the Isabelle
  3870 distribution being used.
  3871 
  3872 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3873 (containing Boolean satisfiability problems) into Isabelle/HOL
  3874 theories.
  3875 
  3876 
  3877 
  3878 New in Isabelle2004 (April 2004)
  3879 --------------------------------
  3880 
  3881 *** General ***
  3882 
  3883 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3884   Replaces linorder.ML.
  3885 
  3886 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3887   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3888   (\<a>...\<z>), are now considered normal letters, and can therefore
  3889   be used anywhere where an ASCII letter (a...zA...Z) has until
  3890   now. COMPATIBILITY: This obviously changes the parsing of some
  3891   terms, especially where a symbol has been used as a binder, say
  3892   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3893   as an identifier.  Fix it by inserting a space around former
  3894   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3895   existing theory and ML files.
  3896 
  3897 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3898 
  3899 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3900   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3901   a normal (but invisible) letter. For multiple letter subscripts repeat
  3902   \<^isub> like this: x\<^isub>1\<^isub>2.
  3903 
  3904 * Pure: There are now sub-/superscripts that can span more than one
  3905   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3906   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3907   superscript. The new control characters are not identifier parts.
  3908 
  3909 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3910   content of "..." to the latex file instead of \isacntrl... . The "..."
  3911   may consist of any printable characters excluding the end bracket >.
  3912 
  3913 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3914   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3915   declare constants "final", which prevents their being given a definition
  3916   later.  It is useful for constants whose behaviour is fixed axiomatically
  3917   rather than definitionally, such as the meta-logic connectives.
  3918 
  3919 * Pure: 'instance' now handles general arities with general sorts
  3920   (i.e. intersections of classes),
  3921 
  3922 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3923   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3924   It can be changed to alter the colors/layout of generated pages.
  3925 
  3926 
  3927 *** Isar ***
  3928 
  3929 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3930   cut_tac, subgoal_tac and thin_tac:
  3931   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3932     locales are no longer forced to write Isar proof scripts.
  3933     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3934     emulations.
  3935   - INCOMPATIBILITY: names of variables to be instantiated may no
  3936     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3937     This is consistent with the instantiation attribute "where".
  3938 
  3939 * Attributes "where" and "of":
  3940   - Now take type variables of instantiated theorem into account when reading
  3941     the instantiation string.  This fixes a bug that caused instantiated
  3942     theorems to have too special types in some circumstances.
  3943   - "where" permits explicit instantiations of type variables.
  3944 
  3945 * Calculation commands "moreover" and "also" no longer interfere with
  3946   current facts ("this"), admitting arbitrary combinations with "then"
  3947   and derived forms.
  3948 
  3949 * Locales:
  3950   - Goal statements involving the context element "includes" no longer
  3951     generate theorems with internal delta predicates (those ending on
  3952     "_axioms") in the premise.
  3953     Resolve particular premise with <locale>.intro to obtain old form.
  3954   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3955     specification and "includes" elements in goal statement.
  3956   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3957     [intro?] and [elim?] (respectively) by default.
  3958   - Experimental command for instantiation of locales in proof contexts:
  3959         instantiate <label>[<attrs>]: <loc>
  3960     Instantiates locale <loc> and adds all its theorems to the current context
  3961     taking into account their attributes.  Label and attrs are optional
  3962     modifiers, like in theorem declarations.  If present, names of
  3963     instantiated theorems are qualified with <label>, and the attributes
  3964     <attrs> are applied after any attributes these theorems might have already.
  3965       If the locale has assumptions, a chained fact of the form
  3966     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3967     are derived.  The command does not support old-style locales declared
  3968     with "locale (open)".
  3969       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3970 
  3971 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3972   (Isar) contexts.
  3973 
  3974 
  3975 *** HOL ***
  3976 
  3977 * Proof import: new image HOL4 contains the imported library from
  3978   the HOL4 system with about 2500 theorems. It is imported by
  3979   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3980   can be used like any other Isabelle image.  See
  3981   HOL/Import/HOL/README for more information.
  3982 
  3983 * Simplifier:
  3984   - Much improved handling of linear and partial orders.
  3985     Reasoners for linear and partial orders are set up for type classes
  3986     "linorder" and "order" respectively, and are added to the default simpset
  3987     as solvers.  This means that the simplifier can build transitivity chains
  3988     to solve goals from the assumptions.
  3989   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3990     of blast or auto after simplification become unnecessary because the goal
  3991     is solved by simplification already.
  3992 
  3993 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3994     all proved in axiomatic type classes for semirings, rings and fields.
  3995 
  3996 * Numerics:
  3997   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3998     now formalized using the Ring_and_Field theory mentioned above.
  3999   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4000     than before, because now they are set up once in a generic manner.
  4001   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4002     Look for the general versions in Ring_and_Field (and Power if they concern
  4003     exponentiation).
  4004 
  4005 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4006 
  4007 * Records:
  4008   - Record types are now by default printed with their type abbreviation
  4009     instead of the list of all field types. This can be configured via
  4010     the reference "print_record_type_abbr".
  4011   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4012     (not enabled by default).
  4013   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4014     EX x. x = sel r to True (not enabled by default).
  4015   - Tactic "record_split_simp_tac" to split and simplify records added.
  4016 
  4017 * 'specification' command added, allowing for definition by
  4018   specification.  There is also an 'ax_specification' command that
  4019   introduces the new constants axiomatically.
  4020 
  4021 * arith(_tac) is now able to generate counterexamples for reals as well.
  4022 
  4023 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4024 
  4025 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4026   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4027 
  4028 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4029   matrix theory to linear programming.
  4030 
  4031 * Unions and Intersections:
  4032   The latex output syntax of UN and INT has been changed
  4033   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4034   i.e. the index formulae has become a subscript.
  4035   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4036 
  4037 * Unions and Intersections over Intervals:
  4038   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4039   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4040   like in normal math, and corresponding versions for < and for intersection.
  4041 
  4042 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4043   lexicographic dictonary ordering has been added as "lexord".
  4044 
  4045 * ML: the legacy theory structures Int and List have been removed. They had
  4046   conflicted with ML Basis Library structures having the same names.
  4047 
  4048 * 'refute' command added to search for (finite) countermodels.  Only works
  4049   for a fragment of HOL.  The installation of an external SAT solver is
  4050   highly recommended.  See "HOL/Refute.thy" for details.
  4051 
  4052 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4053   formulae under an assignment of free variables to random values.
  4054   In contrast to 'refute', it can deal with inductive datatypes,
  4055   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4056   for examples.
  4057 
  4058 
  4059 *** HOLCF ***
  4060 
  4061 * Streams now come with concatenation and are part of the HOLCF image
  4062 
  4063 
  4064 
  4065 New in Isabelle2003 (May 2003)
  4066 ------------------------------
  4067 
  4068 *** General ***
  4069 
  4070 * Provers/simplifier:
  4071 
  4072   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4073     Assumptions are now subject to complete mutual simplification,
  4074     not just from left to right. The simplifier now preserves
  4075     the order of assumptions.
  4076 
  4077     Potential INCOMPATIBILITY:
  4078 
  4079     -- simp sometimes diverges where the old version did
  4080        not, e.g. invoking simp on the goal
  4081 
  4082         [| P (f x); y = x; f x = f y |] ==> Q
  4083 
  4084        now gives rise to the infinite reduction sequence
  4085 
  4086         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4087 
  4088        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4089        kind of problem.
  4090 
  4091     -- Tactics combining classical reasoner and simplification (such as auto)
  4092        are also affected by this change, because many of them rely on
  4093        simp. They may sometimes diverge as well or yield a different numbers
  4094        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4095        in case of problems. Sometimes subsequent calls to the classical
  4096        reasoner will fail because a preceeding call to the simplifier too
  4097        eagerly simplified the goal, e.g. deleted redundant premises.
  4098 
  4099   - The simplifier trace now shows the names of the applied rewrite rules
  4100 
  4101   - You can limit the number of recursive invocations of the simplifier
  4102     during conditional rewriting (where the simplifie tries to solve the
  4103     conditions before applying the rewrite rule):
  4104     ML "simp_depth_limit := n"
  4105     where n is an integer. Thus you can force termination where previously
  4106     the simplifier would diverge.
  4107 
  4108   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4109 
  4110   - No longer aborts on failed congruence proof.  Instead, the
  4111     congruence is ignored.
  4112 
  4113 * Pure: New generic framework for extracting programs from constructive
  4114   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4115   as HOL/Extraction for some case studies.
  4116 
  4117 * Pure: The main goal of the proof state is no longer shown by default, only
  4118 the subgoals. This behaviour is controlled by a new flag.
  4119    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4120 (ML: Proof.show_main_goal).
  4121 
  4122 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4123 rules whose conclusion matches subgoal 1:
  4124       PG menu: Isabelle/Isar -> Show me -> matching rules
  4125 The rules are ordered by how closely they match the subgoal.
  4126 In particular, rules that solve a subgoal outright are displayed first
  4127 (or rather last, the way they are printed).
  4128 (ML: ProofGeneral.print_intros())
  4129 
  4130 * Pure: New flag trace_unify_fail causes unification to print
  4131 diagnostic information (PG: in trace buffer) when it fails. This is
  4132 useful for figuring out why single step proofs like rule, erule or
  4133 assumption failed.
  4134 
  4135 * Pure: Locale specifications now produce predicate definitions
  4136 according to the body of text (covering assumptions modulo local
  4137 definitions); predicate "loc_axioms" covers newly introduced text,
  4138 while "loc" is cumulative wrt. all included locale expressions; the
  4139 latter view is presented only on export into the global theory
  4140 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4141 on the old view without predicates;
  4142 
  4143 * Pure: predefined locales "var" and "struct" are useful for sharing
  4144 parameters (as in CASL, for example); just specify something like
  4145 ``var x + var y + struct M'' as import;
  4146 
  4147 * Pure: improved thms_containing: proper indexing of facts instead of
  4148 raw theorems; check validity of results wrt. current name space;
  4149 include local facts of proof configuration (also covers active
  4150 locales), cover fixed variables in index; may use "_" in term
  4151 specification; an optional limit for the number of printed facts may
  4152 be given (the default is 40);
  4153 
  4154 * Pure: disallow duplicate fact bindings within new-style theory files
  4155 (batch-mode only);
  4156 
  4157 * Provers: improved induct method: assumptions introduced by case
  4158 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4159 the goal statement); "foo" still refers to all facts collectively;
  4160 
  4161 * Provers: the function blast.overloaded has been removed: all constants
  4162 are regarded as potentially overloaded, which improves robustness in exchange
  4163 for slight decrease in efficiency;
  4164 
  4165 * Provers/linorder: New generic prover for transitivity reasoning over
  4166 linear orders.  Note: this prover is not efficient!
  4167 
  4168 * Isar: preview of problems to finish 'show' now produce an error
  4169 rather than just a warning (in interactive mode);
  4170 
  4171 
  4172 *** HOL ***
  4173 
  4174 * arith(_tac)
  4175 
  4176  - Produces a counter example if it cannot prove a goal.
  4177    Note that the counter example may be spurious if the goal is not a formula
  4178    of quantifier-free linear arithmetic.
  4179    In ProofGeneral the counter example appears in the trace buffer.
  4180 
  4181  - Knows about div k and mod k where k is a numeral of type nat or int.
  4182 
  4183  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4184    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4185    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4186 
  4187 * simp's arithmetic capabilities have been enhanced a bit: it now
  4188 takes ~= in premises into account (by performing a case split);
  4189 
  4190 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4191 are distributed over a sum of terms;
  4192 
  4193 * New tactic "trans_tac" and method "trans" instantiate
  4194 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4195 "<=", "<" and "=").
  4196 
  4197 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4198 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4199 
  4200 * 'typedef' command has new option "open" to suppress the set
  4201 definition;
  4202 
  4203 * functions Min and Max on finite sets have been introduced (theory
  4204 Finite_Set);
  4205 
  4206 * attribute [symmetric] now works for relations as well; it turns
  4207 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4208 
  4209 * induct over a !!-quantified statement (say !!x1..xn):
  4210   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4211 
  4212 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4213 %x. None. Warning: empty_def now refers to the previously hidden definition
  4214 of the empty set.
  4215 
  4216 * Algebra: formalization of classical algebra.  Intended as base for
  4217 any algebraic development in Isabelle.  Currently covers group theory
  4218 (up to Sylow's theorem) and ring theory (Universal Property of
  4219 Univariate Polynomials).  Contributions welcome;
  4220 
  4221 * GroupTheory: deleted, since its material has been moved to Algebra;
  4222 
  4223 * Complex: new directory of the complex numbers with numeric constants,
  4224 nonstandard complex numbers, and some complex analysis, standard and
  4225 nonstandard (Jacques Fleuriot);
  4226 
  4227 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4228 
  4229 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4230 Fleuriot);
  4231 
  4232 * Real/HahnBanach: updated and adapted to locales;
  4233 
  4234 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4235 Gray and Kramer);
  4236 
  4237 * UNITY: added the Meier-Sanders theory of progress sets;
  4238 
  4239 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4240 as abstract algorithms, instantiated to the JVM;
  4241 
  4242 * Bali: Java source language formalization. Type system, operational
  4243 semantics, axiomatic semantics. Supported language features:
  4244 classes, interfaces, objects,virtual methods, static methods,
  4245 static/instance fields, arrays, access modifiers, definite
  4246 assignment, exceptions.
  4247 
  4248 
  4249 *** ZF ***
  4250 
  4251 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4252 universe, etc.);
  4253 
  4254 * Main ZF: virtually all theories converted to new-style format;
  4255 
  4256 
  4257 *** ML ***
  4258 
  4259 * Pure: Tactic.prove provides sane interface for internal proofs;
  4260 omits the infamous "standard" operation, so this is more appropriate
  4261 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4262 
  4263 * Pure: improved error reporting of simprocs;
  4264 
  4265 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4266 up simprocs;
  4267 
  4268 
  4269 *** Document preparation ***
  4270 
  4271 * uses \par instead of \\ for line breaks in theory text. This may
  4272 shift some page breaks in large documents. To get the old behaviour
  4273 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4274 
  4275 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4276 other packages
  4277 
  4278 * \<euro> now needs package babel/greek instead of marvosym (which
  4279 broke \Rightarrow)
  4280 
  4281 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4282 textcomp package)
  4283 
  4284 
  4285 
  4286 New in Isabelle2002 (March 2002)
  4287 --------------------------------
  4288 
  4289 *** Document preparation ***
  4290 
  4291 * greatly simplified document preparation setup, including more
  4292 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4293 instructive isatool mkdir; users should basically be able to get
  4294 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4295 users may run a separate document processing stage manually like this:
  4296 "isatool usedir -D output HOL Test && isatool document Test/output";
  4297 
  4298 * theory dependency graph may now be incorporated into documents;
  4299 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4300 with \includegraphics of LaTeX;
  4301 
  4302 * proper spacing of consecutive markup elements, especially text
  4303 blocks after section headings;
  4304 
  4305 * support bold style (for single symbols only), input syntax is like
  4306 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4307 
  4308 * \<bullet> is now output as bold \cdot by default, which looks much
  4309 better in printed text;
  4310 
  4311 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4312 note that these symbols are currently unavailable in Proof General /
  4313 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4314 
  4315 * isatool latex no longer depends on changed TEXINPUTS, instead
  4316 isatool document copies the Isabelle style files to the target
  4317 location;
  4318 
  4319 
  4320 *** Isar ***
  4321 
  4322 * Pure/Provers: improved proof by cases and induction;
  4323   - 'case' command admits impromptu naming of parameters (such as
  4324     "case (Suc n)");
  4325   - 'induct' method divinates rule instantiation from the inductive
  4326     claim; no longer requires excessive ?P bindings for proper
  4327     instantiation of cases;
  4328   - 'induct' method properly enumerates all possibilities of set/type
  4329     rules; as a consequence facts may be also passed through *type*
  4330     rules without further ado;
  4331   - 'induct' method now derives symbolic cases from the *rulified*
  4332     rule (before it used to rulify cases stemming from the internal
  4333     atomized version); this means that the context of a non-atomic
  4334     statement becomes is included in the hypothesis, avoiding the
  4335     slightly cumbersome show "PROP ?case" form;
  4336   - 'induct' may now use elim-style induction rules without chaining
  4337     facts, using ``missing'' premises from the goal state; this allows
  4338     rules stemming from inductive sets to be applied in unstructured
  4339     scripts, while still benefitting from proper handling of non-atomic
  4340     statements; NB: major inductive premises need to be put first, all
  4341     the rest of the goal is passed through the induction;
  4342   - 'induct' proper support for mutual induction involving non-atomic
  4343     rule statements (uses the new concept of simultaneous goals, see
  4344     below);
  4345   - append all possible rule selections, but only use the first
  4346     success (no backtracking);
  4347   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4348   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4349   - added 'print_induct_rules' (covered by help item in recent Proof
  4350     General versions);
  4351   - moved induct/cases attributes to Pure, methods to Provers;
  4352   - generic method setup instantiated for FOL and HOL;
  4353 
  4354 * Pure: support multiple simultaneous goal statements, for example
  4355 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4356 meta-level mechanism, this acts as if several individual goals had
  4357 been stated separately; in particular common proof methods need to be
  4358 repeated in order to cover all claims; note that a single elimination
  4359 step is *not* sufficient to establish the two conjunctions, so this
  4360 fails:
  4361 
  4362   assume "A & B" then have A and B ..   (*".." fails*)
  4363 
  4364 better use "obtain" in situations as above; alternative refer to
  4365 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4366 
  4367 * Pure: proper integration with ``locales''; unlike the original
  4368 version by Florian Kammller, Isar locales package high-level proof
  4369 contexts rather than raw logical ones (e.g. we admit to include
  4370 attributes everywhere); operations on locales include merge and
  4371 rename; support for implicit arguments (``structures''); simultaneous
  4372 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4373 some examples;
  4374 
  4375 * Pure: the following commands have been ``localized'', supporting a
  4376 target locale specification "(in name)": 'lemma', 'theorem',
  4377 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4378 stored both within the locale and at the theory level (exported and
  4379 qualified by the locale name);
  4380 
  4381 * Pure: theory goals may now be specified in ``long'' form, with
  4382 ad-hoc contexts consisting of arbitrary locale elements. for example
  4383 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4384 definitions may be given, too); the result is a meta-level rule with
  4385 the context elements being discharged in the obvious way;
  4386 
  4387 * Pure: new proof command 'using' allows to augment currently used
  4388 facts after a goal statement ('using' is syntactically analogous to
  4389 'apply', but acts on the goal's facts only); this allows chained facts
  4390 to be separated into parts given before and after a claim, as in
  4391 ``from a and b have C using d and e <proof>'';
  4392 
  4393 * Pure: renamed "antecedent" case to "rule_context";
  4394 
  4395 * Pure: new 'judgment' command records explicit information about the
  4396 object-logic embedding (used by several tools internally); no longer
  4397 use hard-wired "Trueprop";
  4398 
  4399 * Pure: added 'corollary' command;
  4400 
  4401 * Pure: fixed 'token_translation' command;
  4402 
  4403 * Pure: removed obsolete 'exported' attribute;
  4404 
  4405 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4406 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4407 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4408 
  4409 * Pure: method 'atomize' presents local goal premises as object-level
  4410 statements (atomic meta-level propositions); setup controlled via
  4411 rewrite rules declarations of 'atomize' attribute; example
  4412 application: 'induct' method with proper rule statements in improper
  4413 proof *scripts*;
  4414 
  4415 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4416 now consider the syntactic context of assumptions, giving a better
  4417 chance to get type-inference of the arguments right (this is
  4418 especially important for locales);
  4419 
  4420 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4421 mode;
  4422 
  4423 * Pure/obtain: the formal conclusion "thesis", being marked as
  4424 ``internal'', may no longer be reference directly in the text;
  4425 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4426 situations;
  4427 
  4428 * Pure: generic 'sym' attribute which declares a rule both as pure
  4429 'elim?' and for the 'symmetric' operation;
  4430 
  4431 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4432 text; the fixed correlation with particular command syntax has been
  4433 discontinued;
  4434 
  4435 * Pure: new method 'rules' is particularly well-suited for proof
  4436 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4437 but often produces more compact proof terms with less detours;
  4438 
  4439 * Pure/Provers/classical: simplified integration with pure rule
  4440 attributes and methods; the classical "intro?/elim?/dest?"
  4441 declarations coincide with the pure ones; the "rule" method no longer
  4442 includes classically swapped intros; "intro" and "elim" methods no
  4443 longer pick rules from the context; also got rid of ML declarations
  4444 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4445 INCOMPATIBILITY;
  4446 
  4447 * Provers/classical: attribute 'swapped' produces classical inversions
  4448 of introduction rules;
  4449 
  4450 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4451 rules instead of full simplifier context; 'iff' attribute handles
  4452 conditional rules;
  4453 
  4454 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4455 
  4456 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4457 "(permissive)" option to recover old behavior;
  4458 
  4459 * HOL: 'inductive' no longer features separate (collective) attributes
  4460 for 'intros' (was found too confusing);
  4461 
  4462 * HOL: properly declared induction rules less_induct and
  4463 wf_induct_rule;
  4464 
  4465 
  4466 *** HOL ***
  4467 
  4468 * HOL: moved over to sane numeral syntax; the new policy is as
  4469 follows:
  4470 
  4471   - 0 and 1 are polymorphic constants, which are defined on any
  4472   numeric type (nat, int, real etc.);
  4473 
  4474   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4475   binary representation internally;
  4476 
  4477   - type nat has special constructor Suc, and generally prefers Suc 0
  4478   over 1::nat and Suc (Suc 0) over 2::nat;
  4479 
  4480 This change may cause significant problems of INCOMPATIBILITY; here
  4481 are some hints on converting existing sources:
  4482 
  4483   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4484   entities, so expressions involving "-" (unary or binary minus) need
  4485   to be spaced properly;
  4486 
  4487   - existing occurrences of "1" may need to be constraint "1::nat" or
  4488   even replaced by Suc 0; similar for old "2";
  4489 
  4490   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4491 
  4492   - remove all special provisions on numerals in proofs;
  4493 
  4494 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4495 representation (depends on bin_arith_simps in the default context);
  4496 
  4497 * HOL: symbolic syntax for x^2 (numeral 2);
  4498 
  4499 * HOL: the class of all HOL types is now called "type" rather than
  4500 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4501 in axclass/classes, instance/arities, and (usually rare) occurrences
  4502 in typings (of consts etc.); internally the class is called
  4503 "HOL.type", ML programs should refer to HOLogic.typeS;
  4504 
  4505 * HOL/record package improvements:
  4506   - new derived operations "fields" to build a partial record section,
  4507     "extend" to promote a fixed record to a record scheme, and
  4508     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4509     declared as simp by default;
  4510   - shared operations ("more", "fields", etc.) now need to be always
  4511     qualified) --- potential INCOMPATIBILITY;
  4512   - removed "make_scheme" operations (use "make" with "extend") --
  4513     INCOMPATIBILITY;
  4514   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4515   - provides cases/induct rules for use with corresponding Isar
  4516     methods (for concrete records, record schemes, concrete more
  4517     parts, and schematic more parts -- in that order);
  4518   - internal definitions directly based on a light-weight abstract
  4519     theory of product types over typedef rather than datatype;
  4520 
  4521 * HOL: generic code generator for generating executable ML code from
  4522 specifications; specific support for HOL constructs such as inductive
  4523 datatypes and sets, as well as recursive functions; can be invoked
  4524 via 'generate_code' theory section;
  4525 
  4526 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4527 
  4528 * HOL: consolidated and renamed several theories.  In particular:
  4529         Ord.thy has been absorbed into HOL.thy
  4530         String.thy has been absorbed into List.thy
  4531 
  4532 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4533 (beware of argument permutation!);
  4534 
  4535 * HOL: linorder_less_split superseded by linorder_cases;
  4536 
  4537 * HOL/List: "nodups" renamed to "distinct";
  4538 
  4539 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4540 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4541   - Ex_def has changed, now need to use some_eq_ex
  4542 
  4543 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4544 in this (rare) case use:
  4545 
  4546   delSWrapper "split_all_tac"
  4547   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4548 
  4549 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4550 MAY FAIL;
  4551 
  4552 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4553 Isabelle's type classes, ^ on functions and relations has too general
  4554 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4555 necessary to attach explicit type constraints;
  4556 
  4557 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4558 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4559 renamed accordingly (eg "compI" -> "rel_compI").
  4560 
  4561 * HOL: syntax translations now work properly with numerals and records
  4562 expressions;
  4563 
  4564 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4565 of "lam" -- INCOMPATIBILITY;
  4566 
  4567 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4568 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4569 renamed "Product_Type.unit";
  4570 
  4571 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4572 
  4573 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4574 the "cases" method);
  4575 
  4576 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4577 Florian Kammller);
  4578 
  4579 * HOL/IMP: updated and converted to new-style theory format; several
  4580 parts turned into readable document, with proper Isar proof texts and
  4581 some explanations (by Gerwin Klein);
  4582 
  4583 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4584 
  4585 * HOL-Hyperreal is now a logic image;
  4586 
  4587 
  4588 *** HOLCF ***
  4589 
  4590 * Isar: consts/constdefs supports mixfix syntax for continuous
  4591 operations;
  4592 
  4593 * Isar: domain package adapted to new-style theory format, e.g. see
  4594 HOLCF/ex/Dnat.thy;
  4595 
  4596 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4597 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4598 lift.induct_tac, always use UU instead of Undef;
  4599 
  4600 * HOLCF/IMP: updated and converted to new-style theory;
  4601 
  4602 
  4603 *** ZF ***
  4604 
  4605 * Isar: proper integration of logic-specific tools and packages,
  4606 including theory commands '(co)inductive', '(co)datatype',
  4607 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4608 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4609 
  4610 * theory Main no longer includes AC; for the Axiom of Choice, base
  4611 your theory on Main_ZFC;
  4612 
  4613 * the integer library now covers quotients and remainders, with many
  4614 laws relating division to addition, multiplication, etc.;
  4615 
  4616 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4617 typeless version of the formalism;
  4618 
  4619 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4620 format;
  4621 
  4622 * ZF/Induct: new directory for examples of inductive definitions,
  4623 including theory Multiset for multiset orderings; converted to
  4624 new-style theory format;
  4625 
  4626 * ZF: many new theorems about lists, ordinals, etc.;
  4627 
  4628 
  4629 *** General ***
  4630 
  4631 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4632 variable proof controls level of detail: 0 = no proofs (only oracle
  4633 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4634 also ref manual for further ML interfaces;
  4635 
  4636 * Pure/axclass: removed obsolete ML interface
  4637 goal_subclass/goal_arity;
  4638 
  4639 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4640 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4641 separate tokens, so expressions involving minus need to be spaced
  4642 properly;
  4643 
  4644 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4645 rather than "infixl" or "infixr";
  4646 
  4647 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4648 sort constraint specifications in type inference; e.g. "x::_::foo"
  4649 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4650 type variable);
  4651 
  4652 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4653 control output of nested => (types); the default behavior is
  4654 "type_brackets";
  4655 
  4656 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4657 tokens into AST constants;
  4658 
  4659 * Pure/syntax: prefer later declarations of translations and print
  4660 translation functions; potential INCOMPATIBILITY: need to reverse
  4661 multiple declarations for same syntax element constant;
  4662 
  4663 * Pure/show_hyps reset by default (in accordance to existing Isar
  4664 practice);
  4665 
  4666 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4667 addSafter;
  4668 
  4669 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4670 as well;
  4671 
  4672 * system: tested support for MacOS X; should be able to get Isabelle +
  4673 Proof General to work in a plain Terminal after installing Poly/ML
  4674 (e.g. from the Isabelle distribution area) and GNU bash alone
  4675 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4676 support requires further installations, e.g. from
  4677 http://fink.sourceforge.net/);
  4678 
  4679 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4680 
  4681 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4682 of 40 MB), cf. ML_OPTIONS;
  4683 
  4684 * system: Proof General keywords specification is now part of the
  4685 Isabelle distribution (see etc/isar-keywords.el);
  4686 
  4687 * system: support for persistent Proof General sessions (refrain from
  4688 outdating all loaded theories on startup); user may create writable
  4689 logic images like this: ``isabelle -q HOL Test'';
  4690 
  4691 * system: smart selection of Isabelle process versus Isabelle
  4692 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4693 run both "isabelle" and "Isabelle" even if file names are badly
  4694 damaged (executable inspects the case of the first letter of its own
  4695 name); added separate "isabelle-process" and "isabelle-interface";
  4696 
  4697 * system: refrain from any attempt at filtering input streams; no
  4698 longer support ``8bit'' encoding of old isabelle font, instead proper
  4699 iso-latin characters may now be used; the related isatools
  4700 "symbolinput" and "nonascii" have disappeared as well;
  4701 
  4702 * system: removed old "xterm" interface (the print modes "xterm" and
  4703 "xterm_color" are still available for direct use in a suitable
  4704 terminal);
  4705 
  4706 
  4707 
  4708 New in Isabelle99-2 (February 2001)
  4709 -----------------------------------
  4710 
  4711 *** Overview of INCOMPATIBILITIES ***
  4712 
  4713 * HOL: please note that theories in the Library and elsewhere often use the
  4714 new-style (Isar) format; to refer to their theorems in an ML script you must
  4715 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4716 
  4717 * HOL: inductive package no longer splits induction rule aggressively,
  4718 but only as far as specified by the introductions given; the old
  4719 format may be recovered via ML function complete_split_rule or attribute
  4720 'split_rule (complete)';
  4721 
  4722 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4723 gfp_Tarski to gfp_unfold;
  4724 
  4725 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4726 
  4727 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4728 relation); infix "^^" has been renamed "``"; infix "``" has been
  4729 renamed "`"; "univalent" has been renamed "single_valued";
  4730 
  4731 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4732 operation;
  4733 
  4734 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4735 
  4736 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4737 
  4738 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4739 consequence, it is no longer monotonic wrt. the local goal context
  4740 (which is now passed through the inductive cases);
  4741 
  4742 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4743 \<gg> to \<ggreater>;
  4744 
  4745 
  4746 *** Document preparation ***
  4747 
  4748 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4749 available: are "it" for near math-mode best-style output, "sl" for
  4750 slanted text style, and "tt" for plain type-writer; if no
  4751 \isabellestyle command is given, output is according to slanted
  4752 type-writer);
  4753 
  4754 * support sub/super scripts (for single symbols only), input syntax is
  4755 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4756 
  4757 * some more standard symbols; see Appendix A of the system manual for
  4758 the complete list of symbols defined in isabellesym.sty;
  4759 
  4760 * improved isabelle style files; more abstract symbol implementation
  4761 (should now use \isamath{...} and \isatext{...} in custom symbol
  4762 definitions);
  4763 
  4764 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4765 state; Note that presentation of goal states does not conform to
  4766 actual human-readable proof documents.  Please do not include goal
  4767 states into document output unless you really know what you are doing!
  4768 
  4769 * proper indentation of antiquoted output with proportional LaTeX
  4770 fonts;
  4771 
  4772 * no_document ML operator temporarily disables LaTeX document
  4773 generation;
  4774 
  4775 * isatool unsymbolize tunes sources for plain ASCII communication;
  4776 
  4777 
  4778 *** Isar ***
  4779 
  4780 * Pure: Isar now suffers initial goal statements to contain unbound
  4781 schematic variables (this does not conform to actual readable proof
  4782 documents, due to unpredictable outcome and non-compositional proof
  4783 checking); users who know what they are doing may use schematic goals
  4784 for Prolog-style synthesis of proven results;
  4785 
  4786 * Pure: assumption method (an implicit finishing) now handles actual
  4787 rules as well;
  4788 
  4789 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4790 initial goal, declare "that" only as Pure intro (only for single
  4791 steps); the "that" rule assumption may now be involved in implicit
  4792 finishing, thus ".." becomes a feasible for trivial obtains;
  4793 
  4794 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4795 instance proofs may be performed by "..";
  4796 
  4797 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4798 statements as well;
  4799 
  4800 * Pure: more robust selection of calculational rules;
  4801 
  4802 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4803 rule (as well as the assumption rule);
  4804 
  4805 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4806 lemmas, using the graph browser tool;
  4807 
  4808 * Pure: predict failure of "show" in interactive mode;
  4809 
  4810 * Pure: 'thms_containing' now takes actual terms as arguments;
  4811 
  4812 * HOL: improved method 'induct' --- now handles non-atomic goals
  4813 (potential INCOMPATIBILITY); tuned error handling;
  4814 
  4815 * HOL: cases and induct rules now provide explicit hints about the
  4816 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4817 any remaining facts are inserted into the goal verbatim;
  4818 
  4819 * HOL: local contexts (aka cases) may now contain term bindings as
  4820 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4821 the result to be shown in each case;
  4822 
  4823 * HOL: added 'recdef_tc' command;
  4824 
  4825 * isatool convert assists in eliminating legacy ML scripts;
  4826 
  4827 
  4828 *** HOL ***
  4829 
  4830 * HOL/Library: a collection of generic theories to be used together
  4831 with main HOL; the theory loader path already includes this directory
  4832 by default; the following existing theories have been moved here:
  4833 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4834 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4835 
  4836 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4837 modelling and verification task performed in Isabelle/HOL +
  4838 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4839 
  4840 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4841 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4842 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4843 'domain', this makes the theory consistent with mathematical
  4844 literature;
  4845 
  4846 * HOL basics: added overloaded operations "inverse" and "divide"
  4847 (infix "/"), syntax for generic "abs" operation, generic summation
  4848 operator \<Sum>;
  4849 
  4850 * HOL/typedef: simplified package, provide more useful rules (see also
  4851 HOL/subset.thy);
  4852 
  4853 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4854 now expressed as a proper nested rule (old-style tactic scripts may
  4855 require atomize_strip_tac to cope with non-atomic premises);
  4856 
  4857 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4858 to "split_conv" (old name still available for compatibility);
  4859 
  4860 * HOL: improved concrete syntax for strings (e.g. allows translation
  4861 rules with string literals);
  4862 
  4863 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4864  and Fleuriot's mechanization of analysis, including the transcendental
  4865  functions for the reals;
  4866 
  4867 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4868 
  4869 
  4870 *** CTT ***
  4871 
  4872 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4873 "lam" is displayed as TWO lambda-symbols
  4874 
  4875 * CTT: theory Main now available, containing everything (that is, Bool
  4876 and Arith);
  4877 
  4878 
  4879 *** General ***
  4880 
  4881 * Pure: the Simplifier has been implemented properly as a derived rule
  4882 outside of the actual kernel (at last!); the overall performance
  4883 penalty in practical applications is about 50%, while reliability of
  4884 the Isabelle inference kernel has been greatly improved;
  4885 
  4886 * print modes "brackets" and "no_brackets" control output of nested =>
  4887 (types) and ==> (props); the default behaviour is "brackets";
  4888 
  4889 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4890 as assumptions as well;
  4891 
  4892 * system: support Poly/ML 4.0;
  4893 
  4894 * system: isatool install handles KDE version 1 or 2;
  4895 
  4896 
  4897 
  4898 New in Isabelle99-1 (October 2000)
  4899 ----------------------------------
  4900 
  4901 *** Overview of INCOMPATIBILITIES ***
  4902 
  4903 * HOL: simplification of natural numbers is much changed; to partly
  4904 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4905 issue the following ML commands:
  4906 
  4907   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4908   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4909 
  4910 * HOL: simplification no longer dives into case-expressions; this is
  4911 controlled by "t.weak_case_cong" for each datatype t;
  4912 
  4913 * HOL: nat_less_induct renamed to less_induct;
  4914 
  4915 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4916 fixsome to patch .thy and .ML sources automatically;
  4917 
  4918   select_equality  -> some_equality
  4919   select_eq_Ex     -> some_eq_ex
  4920   selectI2EX       -> someI2_ex
  4921   selectI2         -> someI2
  4922   selectI          -> someI
  4923   select1_equality -> some1_equality
  4924   Eps_sym_eq       -> some_sym_eq_trivial
  4925   Eps_eq           -> some_eq_trivial
  4926 
  4927 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4928 
  4929 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4930 instead);
  4931 
  4932 * HOL: the recursion equations generated by 'recdef' are now called
  4933 f.simps instead of f.rules;
  4934 
  4935 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4936 
  4937 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4938 sometimes be needed;
  4939 
  4940 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4941 
  4942 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4943 
  4944 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4945 product is now "<*>" instead of "Times"; the lexicographic product is
  4946 now "<*lex*>" instead of "**";
  4947 
  4948 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4949 of main HOL, but was unused); better use HOL's datatype package;
  4950 
  4951 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4952 the old syntax may be recovered as follows:
  4953 
  4954   syntax (symbols)
  4955     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4956       (infixl "\\<oplus>" 100)
  4957 
  4958 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4959 
  4960 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4961 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4962 internally;
  4963 
  4964 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4965 changed from A/r to A//r;
  4966 
  4967 * ZF: new treatment of arithmetic (nat & int) may break some old
  4968 proofs;
  4969 
  4970 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4971 rulify -> rule_format, elimify -> elim_format, ...);
  4972 
  4973 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4974 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4975 should have to change intro!! to intro? only); replaced "delrule" by
  4976 "rule del";
  4977 
  4978 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4979 
  4980 * Provers: strengthened force_tac by using new first_best_tac;
  4981 
  4982 * LaTeX document preparation: several changes of isabelle.sty (see
  4983 lib/texinputs);
  4984 
  4985 
  4986 *** Document preparation ***
  4987 
  4988 * formal comments (text blocks etc.) in new-style theories may now
  4989 contain antiquotations of thm/prop/term/typ/text to be presented
  4990 according to latex print mode; concrete syntax is like this:
  4991 @{term[show_types] "f(x) = a + x"};
  4992 
  4993 * isatool mkdir provides easy setup of Isabelle session directories,
  4994 including proper document sources;
  4995 
  4996 * generated LaTeX sources are now deleted after successful run
  4997 (isatool document -c); may retain a copy somewhere else via -D option
  4998 of isatool usedir;
  4999 
  5000 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5001 style files, achieving self-contained LaTeX sources and simplifying
  5002 LaTeX debugging;
  5003 
  5004 * old-style theories now produce (crude) LaTeX output as well;
  5005 
  5006 * browser info session directories are now self-contained (may be put
  5007 on WWW server seperately); improved graphs of nested sessions; removed
  5008 graph for 'all sessions';
  5009 
  5010 * several improvements in isabelle style files; \isabellestyle{it}
  5011 produces fake math mode output; \isamarkupheader is now \section by
  5012 default; see lib/texinputs/isabelle.sty etc.;
  5013 
  5014 
  5015 *** Isar ***
  5016 
  5017 * Isar/Pure: local results and corresponding term bindings are now
  5018 subject to Hindley-Milner polymorphism (similar to ML); this
  5019 accommodates incremental type-inference very nicely;
  5020 
  5021 * Isar/Pure: new derived language element 'obtain' supports
  5022 generalized existence reasoning;
  5023 
  5024 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5025 support accumulation of results, without applying any rules yet;
  5026 useful to collect intermediate results without explicit name
  5027 references, and for use with transitivity rules with more than 2
  5028 premises;
  5029 
  5030 * Isar/Pure: scalable support for case-analysis type proofs: new
  5031 'case' language element refers to local contexts symbolically, as
  5032 produced by certain proof methods; internally, case names are attached
  5033 to theorems as "tags";
  5034 
  5035 * Isar/Pure: theory command 'hide' removes declarations from
  5036 class/type/const name spaces;
  5037 
  5038 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5039 indicate potential overloading;
  5040 
  5041 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5042 
  5043 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5044 "{a,b,c}" instead of {a,b,c};
  5045 
  5046 * Isar/Pure now provides its own version of intro/elim/dest
  5047 attributes; useful for building new logics, but beware of confusion
  5048 with the version in Provers/classical;
  5049 
  5050 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5051 case name 'antecedent';
  5052 
  5053 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5054 to the current context is now done automatically);
  5055 
  5056 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5057 for definining proof methods in ML;
  5058 
  5059 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5060 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5061 most cases, one should have to change intro!! to intro? only);
  5062 replaced "delrule" by "rule del";
  5063 
  5064 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5065 'symmetric' attribute (the latter supercedes [RS sym]);
  5066 
  5067 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5068 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5069 well (including splits);
  5070 
  5071 * Isar/Provers: Simplifier and Classical methods now support all kind
  5072 of modifiers used in the past, including 'cong', 'iff', etc.
  5073 
  5074 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5075 of Simplifier and Classical reasoner);
  5076 
  5077 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5078 now support named cases; major packages (inductive, datatype, primrec,
  5079 recdef) support case names and properly name parameters;
  5080 
  5081 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5082 monotonicity conditions are extracted to be proven at end of
  5083 calculations;
  5084 
  5085 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5086 method anyway;
  5087 
  5088 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5089 split_if split_if_asm; datatype package provides theorems foo.splits =
  5090 foo.split foo.split_asm for each datatype;
  5091 
  5092 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5093 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5094 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5095 use "(cases (simplified))" method in proper proof texts);
  5096 
  5097 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5098 
  5099 * Isar: names of theorems etc. may be natural numbers as well;
  5100 
  5101 * Isar: 'pr' command: optional arguments for goals_limit and
  5102 ProofContext.prems_limit; no longer prints theory contexts, but only
  5103 proof states;
  5104 
  5105 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5106 additional print modes to be specified; e.g. "pr(latex)" will print
  5107 proof state according to the Isabelle LaTeX style;
  5108 
  5109 * Isar: improved support for emulating tactic scripts, including proof
  5110 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5111 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5112 (for HOL datatypes);
  5113 
  5114 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5115 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5116 'proof method scripts' have to be in depth-first order;
  5117 
  5118 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5119 
  5120 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5121 should instead use individual commands for printing items
  5122 (print_commands, print_methods etc.);
  5123 
  5124 * Isar: added 'nothing' --- the empty list of theorems;
  5125 
  5126 
  5127 *** HOL ***
  5128 
  5129 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5130 corresponding virtual machine and a specification of its bytecode
  5131 verifier and a lightweight bytecode verifier, including proofs of
  5132 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5133 Cornelia Pusch (see also the homepage of project Bali at
  5134 http://isabelle.in.tum.de/Bali/);
  5135 
  5136 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5137 Clemens Ballarin;
  5138 
  5139 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5140 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5141 Rasmussen;
  5142 
  5143 * HOL/Lattice: fundamental concepts of lattice theory and order
  5144 structures, including duals, properties of bounds versus algebraic
  5145 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5146 Theorem for complete lattices etc.; may also serve as a demonstration
  5147 for abstract algebraic reasoning using axiomatic type classes, and
  5148 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5149 
  5150 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5151 von Oheimb;
  5152 
  5153 * HOL/IMPP: extension of IMP with local variables and mutually
  5154 recursive procedures, by David von Oheimb;
  5155 
  5156 * HOL/Lambda: converted into new-style theory and document;
  5157 
  5158 * HOL/ex/Multiquote: example of multiple nested quotations and
  5159 anti-quotations -- basically a generalized version of de-Bruijn
  5160 representation; very useful in avoiding lifting of operations;
  5161 
  5162 * HOL/record: added general record equality rule to simpset; fixed
  5163 select-update simplification procedure to handle extended records as
  5164 well; admit "r" as field name;
  5165 
  5166 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5167 other numeric types and also as the identity of groups, rings, etc.;
  5168 
  5169 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5170 Types nat and int belong to this axclass;
  5171 
  5172 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5173    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5174    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5175   two terms #m*u and #n*u are replaced by #(m+n)*u
  5176     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5177   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5178     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5179 
  5180 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5181 powerful prover for predicate logic but knows nothing of clasets; see
  5182 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5183 
  5184 * HOL: new version of "case_tac" subsumes both boolean case split and
  5185 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5186 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5187 
  5188 * HOL: simplification no longer dives into case-expressions: only the
  5189 selector expression is simplified, but not the remaining arms; to
  5190 enable full simplification of case-expressions for datatype t, you may
  5191 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5192 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5193 
  5194 * HOL/recdef: the recursion equations generated by 'recdef' for
  5195 function 'f' are now called f.simps instead of f.rules; if all
  5196 termination conditions are proved automatically, these simplification
  5197 rules are added to the simpset, as in primrec; rules may be named
  5198 individually as well, resulting in a separate list of theorems for
  5199 each equation;
  5200 
  5201 * HOL/While is a new theory that provides a while-combinator. It
  5202 permits the definition of tail-recursive functions without the
  5203 provision of a termination measure. The latter is necessary once the
  5204 invariant proof rule for while is applied.
  5205 
  5206 * HOL: new (overloaded) notation for the set of elements below/above
  5207 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5208 
  5209 * HOL: theorems impI, allI, ballI bound as "strip";
  5210 
  5211 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5212 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5213 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5214 
  5215 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5216 
  5217 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5218 main HOL, but was unused);
  5219 
  5220 * HOL: fewer consts declared as global (e.g. have to refer to
  5221 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5222 
  5223 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5224 in case of overlap with user translations (e.g. judgements over
  5225 tuples); (note that the underlying logical represenation is still
  5226 bogus);
  5227 
  5228 
  5229 *** ZF ***
  5230 
  5231 * ZF: simplification automatically cancels common terms in arithmetic
  5232 expressions over nat and int;
  5233 
  5234 * ZF: new treatment of nat to minimize type-checking: all operators
  5235 coerce their operands to a natural number using the function natify,
  5236 making the algebraic laws unconditional;
  5237 
  5238 * ZF: as above, for int: operators coerce their operands to an integer
  5239 using the function intify;
  5240 
  5241 * ZF: the integer library now contains many of the usual laws for the
  5242 orderings, including $<=, and monotonicity laws for $+ and $*;
  5243 
  5244 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5245 simplification;
  5246 
  5247 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5248 to the simplifier and classical reasoner simultaneously;
  5249 
  5250 
  5251 *** General ***
  5252 
  5253 * Provers: blast_tac now handles actual object-logic rules as
  5254 assumptions; note that auto_tac uses blast_tac internally as well;
  5255 
  5256 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5257 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5258 
  5259 * Provers: delrules now handles destruct rules as well (no longer need
  5260 explicit make_elim);
  5261 
  5262 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5263   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5264 use instead the strong form,
  5265   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5266 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5267 from destruct-rules;
  5268 
  5269 * Provers: Simplifier.easy_setup provides a fast path to basic
  5270 Simplifier setup for new object-logics;
  5271 
  5272 * Pure: AST translation rules no longer require constant head on LHS;
  5273 
  5274 * Pure: improved name spaces: ambiguous output is qualified; support
  5275 for hiding of names;
  5276 
  5277 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5278 XSYMBOL_HOME; no longer need to do manual configuration in most
  5279 situations;
  5280 
  5281 * system: compression of ML heaps images may now be controlled via -c
  5282 option of isabelle and isatool usedir (currently only observed by
  5283 Poly/ML);
  5284 
  5285 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5286 useful for remote X11);
  5287 
  5288 * system: provide TAGS file for Isabelle sources;
  5289 
  5290 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5291 order;
  5292 
  5293 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5294 timing flag supersedes proof_timing and Toplevel.trace;
  5295 
  5296 * ML: new combinators |>> and |>>> for incremental transformations
  5297 with secondary results (e.g. certain theory extensions):
  5298 
  5299 * ML: PureThy.add_defs gets additional argument to indicate potential
  5300 overloading (usually false);
  5301 
  5302 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5303 results;
  5304 
  5305 
  5306 
  5307 New in Isabelle99 (October 1999)
  5308 --------------------------------
  5309 
  5310 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5311 
  5312 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5313 are no longer simplified.  (This allows the simplifier to unfold recursive
  5314 functional programs.)  To restore the old behaviour, declare
  5315 
  5316     Delcongs [if_weak_cong];
  5317 
  5318 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5319 complement;
  5320 
  5321 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5322 
  5323 * HOL/datatype: mutual_induct_tac no longer exists --
  5324   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5325 
  5326 * HOL/typedef: fixed type inference for representing set; type
  5327 arguments now have to occur explicitly on the rhs as type constraints;
  5328 
  5329 * ZF: The con_defs part of an inductive definition may no longer refer
  5330 to constants declared in the same theory;
  5331 
  5332 * HOL, ZF: the function mk_cases, generated by the inductive
  5333 definition package, has lost an argument.  To simplify its result, it
  5334 uses the default simpset instead of a supplied list of theorems.
  5335 
  5336 * HOL/List: the constructors of type list are now Nil and Cons;
  5337 
  5338 * Simplifier: the type of the infix ML functions
  5339         setSSolver addSSolver setSolver addSolver
  5340 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5341 for packaging solvers. A solver is created via
  5342         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5343 where the string argument is only a comment.
  5344 
  5345 
  5346 *** Proof tools ***
  5347 
  5348 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5349 decision procedure for linear arithmetic. Currently it is used for
  5350 types `nat', `int', and `real' in HOL (see below); it can, should and
  5351 will be instantiated for other types and logics as well.
  5352 
  5353 * The simplifier now accepts rewrite rules with flexible heads, eg
  5354      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5355   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5356   matching.
  5357 
  5358 
  5359 *** General ***
  5360 
  5361 * New Isabelle/Isar subsystem provides an alternative to traditional
  5362 tactical theorem proving; together with the ProofGeneral/isar user
  5363 interface it offers an interactive environment for developing human
  5364 readable proof documents (Isar == Intelligible semi-automated
  5365 reasoning); for further information see isatool doc isar-ref,
  5366 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5367 
  5368 * improved and simplified presentation of theories: better HTML markup
  5369 (including colors), graph views in several sizes; isatool usedir now
  5370 provides a proper interface for user theories (via -P option); actual
  5371 document preparation based on (PDF)LaTeX is available as well (for
  5372 new-style theories only); see isatool doc system for more information;
  5373 
  5374 * native support for Proof General, both for classic Isabelle and
  5375 Isabelle/Isar;
  5376 
  5377 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5378 using the graph browser tool;
  5379 
  5380 * Isabelle manuals now also available as PDF;
  5381 
  5382 * theory loader rewritten from scratch (may not be fully
  5383 bug-compatible); old loadpath variable has been replaced by show_path,
  5384 add_path, del_path, reset_path functions; new operations such as
  5385 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5386 isatool doc ref);
  5387 
  5388 * improved isatool install: option -k creates KDE application icon,
  5389 option -p DIR installs standalone binaries;
  5390 
  5391 * added ML_PLATFORM setting (useful for cross-platform installations);
  5392 more robust handling of platform specific ML images for SML/NJ;
  5393 
  5394 * the settings environment is now statically scoped, i.e. it is never
  5395 created again in sub-processes invoked from isabelle, isatool, or
  5396 Isabelle;
  5397 
  5398 * path element specification '~~' refers to '$ISABELLE_HOME';
  5399 
  5400 * in locales, the "assumes" and "defines" parts may be omitted if
  5401 empty;
  5402 
  5403 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5404 long arrows);
  5405 
  5406 * new print_mode "HTML";
  5407 
  5408 * new flag show_tags controls display of tags of theorems (which are
  5409 basically just comments that may be attached by some tools);
  5410 
  5411 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5412 mode and goal output format:
  5413 
  5414 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5415 244c244
  5416 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5417 ---
  5418 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5419 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5420 181c181
  5421 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5422 ---
  5423 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5424 
  5425 * function bind_thms stores lists of theorems (cf. bind_thm);
  5426 
  5427 * new shorthand tactics ftac, eatac, datac, fatac;
  5428 
  5429 * qed (and friends) now accept "" as result name; in that case the
  5430 theorem is not stored, but proper checks and presentation of the
  5431 result still apply;
  5432 
  5433 * theorem database now also indexes constants "Trueprop", "all",
  5434 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5435 
  5436 
  5437 *** HOL ***
  5438 
  5439 ** HOL arithmetic **
  5440 
  5441 * There are now decision procedures for linear arithmetic over nat and
  5442 int:
  5443 
  5444 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5445 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5446 are treated as atomic; subformulae not involving type `nat' or `int'
  5447 are ignored; quantified subformulae are ignored unless they are
  5448 positive universal or negative existential. The tactic has to be
  5449 invoked by hand and can be a little bit slow. In particular, the
  5450 running time is exponential in the number of occurrences of `min' and
  5451 `max', and `-' on `nat'.
  5452 
  5453 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5454 (negated) (in)equalities among the premises and the conclusion into
  5455 account (i.e. no compound formulae) and does not know about `min' and
  5456 `max', and `-' on `nat'. It is fast and is used automatically by the
  5457 simplifier.
  5458 
  5459 NB: At the moment, these decision procedures do not cope with mixed
  5460 nat/int formulae where the two parts interact, such as `m < n ==>
  5461 int(m) < int(n)'.
  5462 
  5463 * HOL/Numeral provides a generic theory of numerals (encoded
  5464 efficiently as bit strings); setup for types nat/int/real is in place;
  5465 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5466 int, existing theories and proof scripts may require a few additional
  5467 type constraints;
  5468 
  5469 * integer division and remainder can now be performed on constant
  5470 arguments;
  5471 
  5472 * many properties of integer multiplication, division and remainder
  5473 are now available;
  5474 
  5475 * An interface to the Stanford Validity Checker (SVC) is available through the
  5476 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5477 are proved automatically.  SVC must be installed separately, and its results
  5478 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5479 invocation of the underlying oracle).  For SVC see
  5480   http://verify.stanford.edu/SVC
  5481 
  5482 * IsaMakefile: the HOL-Real target now builds an actual image;
  5483 
  5484 
  5485 ** HOL misc **
  5486 
  5487 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5488 (in Isabelle/Isar) -- by Gertrud Bauer;
  5489 
  5490 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5491 analysis for assembly languages with subtypes;
  5492 
  5493 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5494 -- avoids syntactic ambiguities and treats state, transition, and
  5495 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5496 changed syntax and (many) tactics;
  5497 
  5498 * HOL/inductive: Now also handles more general introduction rules such
  5499   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5500   theorems are now maintained within the theory (maintained via the
  5501   "mono" attribute);
  5502 
  5503 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5504   (using function types) such as
  5505 
  5506   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5507 
  5508 * HOL/record: record_simproc (part of the default simpset) takes care
  5509 of selectors applied to updated records; record_split_tac is no longer
  5510 part of the default claset; update_defs may now be removed from the
  5511 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5512 
  5513   claset_ref () := claset() addSWrapper record_split_wrapper;
  5514   Delsimprocs [record_simproc]
  5515 
  5516 * HOL/typedef: fixed type inference for representing set; type
  5517 arguments now have to occur explicitly on the rhs as type constraints;
  5518 
  5519 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5520 names rather than an ML expression;
  5521 
  5522 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5523 supplied later.  Program schemes can be defined, such as
  5524     "While B C s = (if B s then While B C (C s) else s)"
  5525 where the well-founded relation can be chosen after B and C have been given.
  5526 
  5527 * HOL/List: the constructors of type list are now Nil and Cons;
  5528 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5529 course, ML tools referring to List.list.op # etc. have to be adapted;
  5530 
  5531 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5532 disabled by default; run isabelle with option -m HOL to get back to
  5533 the original Gordon/HOL-style output;
  5534 
  5535 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5536 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5537 
  5538 * HOL basic syntax simplified (more orthogonal): all variants of
  5539 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5540 Eps operator is provided as well: "SOME x. P[x]";
  5541 
  5542 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5543 
  5544 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5545 thus available for user theories;
  5546 
  5547 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5548 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5549 time;
  5550 
  5551 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5552 several times and then mp;
  5553 
  5554 
  5555 *** LK ***
  5556 
  5557 * the notation <<...>> is now available as a notation for sequences of
  5558 formulas;
  5559 
  5560 * the simplifier is now installed
  5561 
  5562 * the axiom system has been generalized (thanks to Soren Heilmann)
  5563 
  5564 * the classical reasoner now has a default rule database
  5565 
  5566 
  5567 *** ZF ***
  5568 
  5569 * new primrec section allows primitive recursive functions to be given
  5570 directly (as in HOL) over datatypes and the natural numbers;
  5571 
  5572 * new tactics induct_tac and exhaust_tac for induction (or case
  5573 analysis) over datatypes and the natural numbers;
  5574 
  5575 * the datatype declaration of type T now defines the recursor T_rec;
  5576 
  5577 * simplification automatically does freeness reasoning for datatype
  5578 constructors;
  5579 
  5580 * automatic type-inference, with AddTCs command to insert new
  5581 type-checking rules;
  5582 
  5583 * datatype introduction rules are now added as Safe Introduction rules
  5584 to the claset;
  5585 
  5586 * the syntax "if P then x else y" is now available in addition to
  5587 if(P,x,y);
  5588 
  5589 
  5590 *** Internal programming interfaces ***
  5591 
  5592 * tuned simplifier trace output; new flag debug_simp;
  5593 
  5594 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5595 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5596 
  5597 * AxClass.axclass_tac lost the theory argument;
  5598 
  5599 * tuned current_goals_markers semantics: begin / end goal avoids
  5600 printing empty lines;
  5601 
  5602 * removed prs and prs_fn hook, which was broken because it did not
  5603 include \n in its semantics, forcing writeln to add one
  5604 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5605 string -> unit if you really want to output text without newline;
  5606 
  5607 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5608 plain output, interface builders may have to enable 'isabelle_font'
  5609 mode to get Isabelle font glyphs as before;
  5610 
  5611 * refined token_translation interface; INCOMPATIBILITY: output length
  5612 now of type real instead of int;
  5613 
  5614 * theory loader actions may be traced via new ThyInfo.add_hook
  5615 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5616 your own database of information attached to *whole* theories -- as
  5617 opposed to intra-theory data slots offered via TheoryDataFun;
  5618 
  5619 * proper handling of dangling sort hypotheses (at last!);
  5620 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5621 extra sort hypotheses that can be witnessed from the type signature;
  5622 the force_strip_shyps flag is gone, any remaining shyps are simply
  5623 left in the theorem (with a warning issued by strip_shyps_warning);
  5624 
  5625 
  5626 
  5627 New in Isabelle98-1 (October 1998)
  5628 ----------------------------------
  5629 
  5630 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5631 
  5632 * several changes of automated proof tools;
  5633 
  5634 * HOL: major changes to the inductive and datatype packages, including
  5635 some minor incompatibilities of theory syntax;
  5636 
  5637 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5638 called `inj_on';
  5639 
  5640 * HOL: removed duplicate thms in Arith:
  5641   less_imp_add_less  should be replaced by  trans_less_add1
  5642   le_imp_add_le      should be replaced by  trans_le_add1
  5643 
  5644 * HOL: unary minus is now overloaded (new type constraints may be
  5645 required);
  5646 
  5647 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5648 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5649 now taken as an integer constant.
  5650 
  5651 * Pure: ML function 'theory_of' renamed to 'theory';
  5652 
  5653 
  5654 *** Proof tools ***
  5655 
  5656 * Simplifier:
  5657   1. Asm_full_simp_tac is now more aggressive.
  5658      1. It will sometimes reorient premises if that increases their power to
  5659         simplify.
  5660      2. It does no longer proceed strictly from left to right but may also
  5661         rotate premises to achieve further simplification.
  5662      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5663      old Asm_full_simp_tac in that it does not rotate premises.
  5664   2. The simplifier now knows a little bit about nat-arithmetic.
  5665 
  5666 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5667 allows for selected deletion of wrappers, by introduction of names for
  5668 wrapper functionals.  This implies that addbefore, addSbefore,
  5669 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5670 and that adding two tactics with the same name overwrites the first
  5671 one (emitting a warning).
  5672   type wrapper = (int -> tactic) -> (int -> tactic)
  5673   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5674   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5675   delWrapper, delSWrapper: claset *  string            -> claset
  5676   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5677 
  5678 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5679 semantics; addbefore now affects only the unsafe part of step_tac
  5680 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5681 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5682 by Force_tac;
  5683 
  5684 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5685 compWrapper; added safe wrapper (and access functions for it);
  5686 
  5687 * HOL/split_all_tac is now much faster and fails if there is nothing
  5688 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5689 and the names of the automatically generated variables have changed.
  5690 split_all_tac has moved within claset() from unsafe wrappers to safe
  5691 wrappers, which means that !!-bound variables are split much more
  5692 aggressively, and safe_tac and clarify_tac now split such variables.
  5693 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5694 Note: the same holds for record_split_tac, which does the job of
  5695 split_all_tac for record fields.
  5696 
  5697 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5698 permanently to the default simpset using Addsplits just like
  5699 Addsimps. They can be removed via Delsplits just like
  5700 Delsimps. Lower-case versions are also available.
  5701 
  5702 * HOL/Simplifier: The rule split_if is now part of the default
  5703 simpset. This means that the simplifier will eliminate all occurrences
  5704 of if-then-else in the conclusion of a goal. To prevent this, you can
  5705 either remove split_if completely from the default simpset by
  5706 `Delsplits [split_if]' or remove it in a specific call of the
  5707 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5708 other case splitting rules to/from the default simpset: every datatype
  5709 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5710 t is the name of the datatype).
  5711 
  5712 * Classical reasoner / Simplifier combination: new force_tac (and
  5713 derivatives Force_tac, force) combines rewriting and classical
  5714 reasoning (and whatever other tools) similarly to auto_tac, but is
  5715 aimed to solve the given subgoal completely.
  5716 
  5717 
  5718 *** General ***
  5719 
  5720 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5721 and `goalw': the theory is no longer needed as an explicit argument -
  5722 the current theory context is used; assumptions are no longer returned
  5723 at the ML-level unless one of them starts with ==> or !!; it is
  5724 recommended to convert to these new commands using isatool fixgoal
  5725 (backup your sources first!);
  5726 
  5727 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5728 the current theory context, and 'theory' to lookup stored theories;
  5729 
  5730 * new theory section 'locale' for declaring constants, assumptions and
  5731 definitions that have local scope;
  5732 
  5733 * new theory section 'nonterminals' for purely syntactic types;
  5734 
  5735 * new theory section 'setup' for generic ML setup functions
  5736 (e.g. package initialization);
  5737 
  5738 * the distribution now includes Isabelle icons: see
  5739 lib/logo/isabelle-{small,tiny}.xpm;
  5740 
  5741 * isatool install - install binaries with absolute references to
  5742 ISABELLE_HOME/bin;
  5743 
  5744 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5745 
  5746 * print mode 'emacs' reserved for Isamode;
  5747 
  5748 * support multiple print (ast) translations per constant name;
  5749 
  5750 * theorems involving oracles are now printed with a suffixed [!];
  5751 
  5752 
  5753 *** HOL ***
  5754 
  5755 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5756 
  5757 * HOL/inductive package reorganized and improved: now supports mutual
  5758 definitions such as
  5759 
  5760   inductive EVEN ODD
  5761     intrs
  5762       null "0 : EVEN"
  5763       oddI "n : EVEN ==> Suc n : ODD"
  5764       evenI "n : ODD ==> Suc n : EVEN"
  5765 
  5766 new theorem list "elims" contains an elimination rule for each of the
  5767 recursive sets; inductive definitions now handle disjunctive premises
  5768 correctly (also ZF);
  5769 
  5770 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5771 "mutual_induct" no longer exists - the induction rule is always
  5772 contained in "induct";
  5773 
  5774 
  5775 * HOL/datatype package re-implemented and greatly improved: now
  5776 supports mutually recursive datatypes such as
  5777 
  5778   datatype
  5779     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5780             | SUM ('a aexp) ('a aexp)
  5781             | DIFF ('a aexp) ('a aexp)
  5782             | NUM 'a
  5783   and
  5784     'a bexp = LESS ('a aexp) ('a aexp)
  5785             | AND ('a bexp) ('a bexp)
  5786             | OR ('a bexp) ('a bexp)
  5787 
  5788 as well as indirectly recursive datatypes such as
  5789 
  5790   datatype
  5791     ('a, 'b) term = Var 'a
  5792                   | App 'b ((('a, 'b) term) list)
  5793 
  5794 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5795 induction on mutually / indirectly recursive datatypes.
  5796 
  5797 Primrec equations are now stored in theory and can be accessed via
  5798 <function_name>.simps.
  5799 
  5800 INCOMPATIBILITIES:
  5801 
  5802   - Theories using datatypes must now have theory Datatype as an
  5803     ancestor.
  5804   - The specific <typename>.induct_tac no longer exists - use the
  5805     generic induct_tac instead.
  5806   - natE has been renamed to nat.exhaust - use exhaust_tac
  5807     instead of res_inst_tac ... natE. Note that the variable
  5808     names in nat.exhaust differ from the names in natE, this
  5809     may cause some "fragile" proofs to fail.
  5810   - The theorems split_<typename>_case and split_<typename>_case_asm
  5811     have been renamed to <typename>.split and <typename>.split_asm.
  5812   - Since default sorts of type variables are now handled correctly,
  5813     some datatype definitions may have to be annotated with explicit
  5814     sort constraints.
  5815   - Primrec definitions no longer require function name and type
  5816     of recursive argument.
  5817 
  5818 Consider using isatool fixdatatype to adapt your theories and proof
  5819 scripts to the new package (backup your sources first!).
  5820 
  5821 
  5822 * HOL/record package: considerably improved implementation; now
  5823 includes concrete syntax for record types, terms, updates; theorems
  5824 for surjective pairing and splitting !!-bound record variables; proof
  5825 support is as follows:
  5826 
  5827   1) standard conversions (selectors or updates applied to record
  5828 constructor terms) are part of the standard simpset;
  5829 
  5830   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5831 made part of standard simpset and claset via addIffs;
  5832 
  5833   3) a tactic for record field splitting (record_split_tac) is part of
  5834 the standard claset (addSWrapper);
  5835 
  5836 To get a better idea about these rules you may retrieve them via
  5837 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5838 the name of your record type.
  5839 
  5840 The split tactic 3) conceptually simplifies by the following rule:
  5841 
  5842   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5843 
  5844 Thus any record variable that is bound by meta-all will automatically
  5845 blow up into some record constructor term, consequently the
  5846 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5847 solve record problems automatically.
  5848 
  5849 
  5850 * reorganized the main HOL image: HOL/Integ and String loaded by
  5851 default; theory Main includes everything;
  5852 
  5853 * automatic simplification of integer sums and comparisons, using cancellation;
  5854 
  5855 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5856 
  5857 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5858 
  5859 * many new identities for unions, intersections, set difference, etc.;
  5860 
  5861 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5862 called split_if, split_split, split_sum_case and split_nat_case (to go
  5863 with add/delsplits);
  5864 
  5865 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5866 (?x::unit) = (); this is made part of the default simpset, which COULD
  5867 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5868 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5869 unit_abs_eta_conv is added in order to counter the effect of
  5870 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5871 %u.f();
  5872 
  5873 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5874 makes more sense);
  5875 
  5876 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5877   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5878   disjointness reasoning but breaking a few old proofs.
  5879 
  5880 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5881 to 'converse' from 'inverse' (for compatibility with ZF and some
  5882 literature);
  5883 
  5884 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5885 the well-founded relation;
  5886 
  5887 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5888     Compl A.  The "Compl" syntax remains available as input syntax for this
  5889     release ONLY.
  5890 
  5891 * HOL/Update: new theory of function updates:
  5892     f(a:=b) == %x. if x=a then b else f x
  5893 may also be iterated as in f(a:=b,c:=d,...);
  5894 
  5895 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5896 
  5897 * HOL/List:
  5898   - new function list_update written xs[i:=v] that updates the i-th
  5899     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5900   - new function `upt' written [i..j(] which generates the list
  5901     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5902     bound write [i..j], which is a shorthand for [i..j+1(].
  5903   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5904 
  5905 * HOL/Arith:
  5906   - removed 'pred' (predecessor) function;
  5907   - generalized some theorems about n-1;
  5908   - many new laws about "div" and "mod";
  5909   - new laws about greatest common divisors (see theory ex/Primes);
  5910 
  5911 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5912 instead of "inverse";
  5913 
  5914 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5915   of the multiset ordering;
  5916 
  5917 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5918   (not included by default);
  5919 
  5920 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5921 
  5922 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5923   programs, i.e. different program variables may have different types.
  5924 
  5925 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5926   [previously, this check worked only if the rewrite rule was unconditional]
  5927   Now rew can involve either definitions or equalities (either == or =).
  5928 
  5929 
  5930 *** ZF ***
  5931 
  5932 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5933   only the theorems proved on ZF.ML;
  5934 
  5935 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5936   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5937   disjointness reasoning but breaking a few old proofs.
  5938 
  5939 * ZF/Update: new theory of function updates
  5940     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5941   may also be iterated as in f(a:=b,c:=d,...);
  5942 
  5943 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5944 
  5945 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5946   [previously, this check worked only if the rewrite rule was unconditional]
  5947   Now rew can involve either definitions or equalities (either == or =).
  5948 
  5949 * case_tac provided for compatibility with HOL
  5950     (like the old excluded_middle_tac, but with subgoals swapped)
  5951 
  5952 
  5953 *** Internal programming interfaces ***
  5954 
  5955 * Pure: several new basic modules made available for general use, see
  5956 also src/Pure/README;
  5957 
  5958 * improved the theory data mechanism to support encapsulation (data
  5959 kind name replaced by private Object.kind, acting as authorization
  5960 key); new type-safe user interface via functor TheoryDataFun; generic
  5961 print_data function becomes basically useless;
  5962 
  5963 * removed global_names compatibility flag -- all theory declarations
  5964 are qualified by default;
  5965 
  5966 * module Pure/Syntax now offers quote / antiquote translation
  5967 functions (useful for Hoare logic etc. with implicit dependencies);
  5968 see HOL/ex/Antiquote for an example use;
  5969 
  5970 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5971 cterm -> thm;
  5972 
  5973 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5974 subgoal;
  5975 
  5976 * Display.print_goals function moved to Locale.print_goals;
  5977 
  5978 * standard print function for goals supports current_goals_markers
  5979 variable for marking begin of proof, end of proof, start of goal; the
  5980 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5981 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5982 for example;
  5983 
  5984 
  5985 
  5986 New in Isabelle98 (January 1998)
  5987 --------------------------------
  5988 
  5989 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5990 
  5991 * changed lexical syntax of terms / types: dots made part of long
  5992 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5993 
  5994 * simpset (and claset) reference variable replaced by functions
  5995 simpset / simpset_ref;
  5996 
  5997 * no longer supports theory aliases (via merge) and non-trivial
  5998 implicit merge of thms' signatures;
  5999 
  6000 * most internal names of constants changed due to qualified names;
  6001 
  6002 * changed Pure/Sequence interface (see Pure/seq.ML);
  6003 
  6004 
  6005 *** General Changes ***
  6006 
  6007 * hierachically structured name spaces (for consts, types, axms, thms
  6008 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6009 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6010 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6011 long_names for fully qualified output names; NOTE: ML programs
  6012 (special tactics, packages etc.) referring to internal names may have
  6013 to be adapted to cope with fully qualified names; in case of severe
  6014 backward campatibility problems try setting 'global_names' at compile
  6015 time to have enrything declared within a flat name space; one may also
  6016 fine tune name declarations in theories via the 'global' and 'local'
  6017 section;
  6018 
  6019 * reimplemented the implicit simpset and claset using the new anytype
  6020 data filed in signatures; references simpset:simpset ref etc. are
  6021 replaced by functions simpset:unit->simpset and
  6022 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6023 to patch your ML files accordingly;
  6024 
  6025 * HTML output now includes theory graph data for display with Java
  6026 applet or isatool browser; data generated automatically via isatool
  6027 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6028 
  6029 * defs may now be conditional; improved rewrite_goals_tac to handle
  6030 conditional equations;
  6031 
  6032 * defs now admits additional type arguments, using TYPE('a) syntax;
  6033 
  6034 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6035 creates a new theory node; implicit merge of thms' signatures is
  6036 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6037 transfer:theory->thm->thm in (rare) cases;
  6038 
  6039 * improved handling of draft signatures / theories; draft thms (and
  6040 ctyps, cterms) are automatically promoted to real ones;
  6041 
  6042 * slightly changed interfaces for oracles: admit many per theory, named
  6043 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6044 
  6045 * print_goals: optional output of const types (set show_consts and
  6046 show_types);
  6047 
  6048 * improved output of warnings (###) and errors (***);
  6049 
  6050 * subgoal_tac displays a warning if the new subgoal has type variables;
  6051 
  6052 * removed old README and Makefiles;
  6053 
  6054 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6055 
  6056 * removed obsolete init_pps and init_database;
  6057 
  6058 * deleted the obsolete tactical STATE, which was declared by
  6059     fun STATE tacfun st = tacfun st st;
  6060 
  6061 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6062 (which abbreviates $HOME);
  6063 
  6064 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6065 use isatool fixseq to adapt your ML programs (this works for fully
  6066 qualified references to the Sequence structure only!);
  6067 
  6068 * use_thy no longer requires writable current directory; it always
  6069 reloads .ML *and* .thy file, if either one is out of date;
  6070 
  6071 
  6072 *** Classical Reasoner ***
  6073 
  6074 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6075 tactics that use classical reasoning to simplify a subgoal without
  6076 splitting it into several subgoals;
  6077 
  6078 * Safe_tac: like safe_tac but uses the default claset;
  6079 
  6080 
  6081 *** Simplifier ***
  6082 
  6083 * added simplification meta rules:
  6084     (asm_)(full_)simplify: simpset -> thm -> thm;
  6085 
  6086 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6087 logics (again);
  6088 
  6089 * added prems argument to simplification procedures;
  6090 
  6091 * HOL, FOL, ZF: added infix function `addsplits':
  6092   instead of `<simpset> setloop (split_tac <thms>)'
  6093   you can simply write `<simpset> addsplits <thms>'
  6094 
  6095 
  6096 *** Syntax ***
  6097 
  6098 * TYPE('a) syntax for type reflection terms;
  6099 
  6100 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6101 
  6102 * pretty printer: changed order of mixfix annotation preference (again!);
  6103 
  6104 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6105 
  6106 
  6107 *** HOL ***
  6108 
  6109 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6110   with `addloop' of the simplifier to faciliate case splitting in premises.
  6111 
  6112 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6113 
  6114 * HOL/Auth: new protocol proofs including some for the Internet
  6115   protocol TLS;
  6116 
  6117 * HOL/Map: new theory of `maps' a la VDM;
  6118 
  6119 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6120 cancelling out common nat summands from =, <, <= (in)equalities, or
  6121 differences; simplification procedures nat_cancel_factor for
  6122 cancelling common factor from =, <, <= (in)equalities over natural
  6123 sums; nat_cancel contains both kinds of procedures, it is installed by
  6124 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6125 
  6126 * HOL/simplifier: terms of the form
  6127   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6128   are rewritten to
  6129   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6130   and those of the form
  6131   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6132   are rewritten to
  6133   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6134 
  6135 * HOL/datatype
  6136   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6137 
  6138   P(t_case f1 ... fn x) =
  6139      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6140         ...
  6141        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6142      )
  6143 
  6144   and a theorem `split_t_case_asm' of the form
  6145 
  6146   P(t_case f1 ... fn x) =
  6147     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6148         ...
  6149        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6150      )
  6151   which can be added to a simpset via `addsplits'. The existing theorems
  6152   expand_list_case and expand_option_case have been renamed to
  6153   split_list_case and split_option_case.
  6154 
  6155 * HOL/Arithmetic:
  6156   - `pred n' is automatically converted to `n-1'.
  6157     Users are strongly encouraged not to use `pred' any longer,
  6158     because it will disappear altogether at some point.
  6159   - Users are strongly encouraged to write "0 < n" rather than
  6160     "n ~= 0". Theorems and proof tools have been modified towards this
  6161     `standard'.
  6162 
  6163 * HOL/Lists:
  6164   the function "set_of_list" has been renamed "set" (and its theorems too);
  6165   the function "nth" now takes its arguments in the reverse order and
  6166   has acquired the infix notation "!" as in "xs!n".
  6167 
  6168 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6169 
  6170 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6171   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6172 
  6173 * HOL/record: extensible records with schematic structural subtyping
  6174 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6175 still lacks various theorems and concrete record syntax;
  6176 
  6177 
  6178 *** HOLCF ***
  6179 
  6180 * removed "axioms" and "generated by" sections;
  6181 
  6182 * replaced "ops" section by extended "consts" section, which is capable of
  6183   handling the continuous function space "->" directly;
  6184 
  6185 * domain package:
  6186   . proves theorems immediately and stores them in the theory,
  6187   . creates hierachical name space,
  6188   . now uses normal mixfix annotations (instead of cinfix...),
  6189   . minor changes to some names and values (for consistency),
  6190   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6191   . separator between mutual domain defs: changed "," to "and",
  6192   . improved handling of sort constraints;  now they have to
  6193     appear on the left-hand side of the equations only;
  6194 
  6195 * fixed LAM <x,y,zs>.b syntax;
  6196 
  6197 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6198 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6199 
  6200 
  6201 *** FOL and ZF ***
  6202 
  6203 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6204   with `addloop' of the simplifier to faciliate case splitting in premises.
  6205 
  6206 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6207 in HOL, they strip ALL and --> from proved theorems;
  6208 
  6209 
  6210 
  6211 New in Isabelle94-8 (May 1997)
  6212 ------------------------------
  6213 
  6214 *** General Changes ***
  6215 
  6216 * new utilities to build / run / maintain Isabelle etc. (in parts
  6217 still somewhat experimental); old Makefiles etc. still functional;
  6218 
  6219 * new 'Isabelle System Manual';
  6220 
  6221 * INSTALL text, together with ./configure and ./build scripts;
  6222 
  6223 * reimplemented type inference for greater efficiency, better error
  6224 messages and clean internal interface;
  6225 
  6226 * prlim command for dealing with lots of subgoals (an easier way of
  6227 setting goals_limit);
  6228 
  6229 
  6230 *** Syntax ***
  6231 
  6232 * supports alternative (named) syntax tables (parser and pretty
  6233 printer); internal interface is provided by add_modesyntax(_i);
  6234 
  6235 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6236 be used in conjunction with the Isabelle symbol font; uses the
  6237 "symbols" syntax table;
  6238 
  6239 * added token_translation interface (may translate name tokens in
  6240 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6241 the current print_mode); IMPORTANT: user print translation functions
  6242 are responsible for marking newly introduced bounds
  6243 (Syntax.mark_boundT);
  6244 
  6245 * token translations for modes "xterm" and "xterm_color" that display
  6246 names in bold, underline etc. or colors (which requires a color
  6247 version of xterm);
  6248 
  6249 * infixes may now be declared with names independent of their syntax;
  6250 
  6251 * added typed_print_translation (like print_translation, but may
  6252 access type of constant);