NEWS
author haftmann
Wed Sep 30 08:28:23 2009 +0200 (2009-09-30)
changeset 32774 461afcc6acb8
parent 32706 b68f3afdc137
child 32775 d498770eefdc
permissions -rw-r--r--
mandatory prefix where appropriate
     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 * Most rules produced by inductive and datatype package
    22 have mandatory prefixes.
    23 INCOMPATIBILITY.
    24 
    25 * New proof method "smt" for a combination of first-order logic
    26 with equality, linear and nonlinear (natural/integer/real)
    27 arithmetic, and fixed-size bitvectors; there is also basic
    28 support for higher-order features (esp. lambda abstractions).
    29 It is an incomplete decision procedure based on external SMT
    30 solvers using the oracle mechanism.
    31 
    32 * Reorganization of number theory:
    33   * former session NumberTheory now named Old_Number_Theory
    34   * new session Number_Theory by Jeremy Avigad; if possible, prefer this.
    35   * moved legacy theories Legacy_GCD and Primes from Library/ to Old_Number_Theory/;
    36   * moved theory Pocklington from Library/ to Old_Number_Theory/;
    37   * removed various references to Old_Number_Theory from HOL distribution.
    38 INCOMPATIBILITY.
    39 
    40 * Theory GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm
    41 of finite and infinite sets. It is shown that they form a complete
    42 lattice.
    43 
    44 * Split off prime number ingredients from theory GCD
    45 to theory Number_Theory/Primes;
    46 
    47 * Class semiring_div requires superclass no_zero_divisors and proof of
    48 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    49 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    50 generalized to class semiring_div, subsuming former theorems
    51 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    52 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    53 INCOMPATIBILITY.
    54 
    55 * New testing tool "Mirabelle" for automated (proof) tools. Applies
    56 several tools and tactics like sledgehammer, metis, or quickcheck, to
    57 every proof step in a theory. To be used in batch mode via the
    58 "mirabelle" utility.
    59 
    60 * New proof method "sos" (sum of squares) for nonlinear real
    61 arithmetic (originally due to John Harison). It requires
    62 Library/Sum_Of_Squares.  It is not a complete decision procedure but
    63 works well in practice on quantifier-free real arithmetic with +, -,
    64 *, ^, =, <= and <, i.e. boolean combinations of equalities and
    65 inequalities between polynomials. It makes use of external
    66 semidefinite programming solvers.  For more information and examples
    67 see src/HOL/Library/Sum_Of_Squares.
    68 
    69 * Code generator attributes follow the usual underscore convention:
    70     code_unfold     replaces    code unfold
    71     code_post       replaces    code post
    72     etc.
    73   INCOMPATIBILITY.
    74 
    75 * Refinements to lattice classes and sets:
    76   - less default intro/elim rules in locale variant, more default
    77     intro/elim rules in class variant: more uniformity
    78   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    79   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    80   - renamed ACI to inf_sup_aci
    81   - new class "boolean_algebra"
    82   - class "complete_lattice" moved to separate theory "complete_lattice";
    83     corresponding constants (and abbreviations) renamed and with authentic syntax:
    84     Set.Inf ~>      Complete_Lattice.Inf
    85     Set.Sup ~>      Complete_Lattice.Sup
    86     Set.INFI ~>     Complete_Lattice.INFI
    87     Set.SUPR ~>     Complete_Lattice.SUPR
    88     Set.Inter ~>    Complete_Lattice.Inter
    89     Set.Union ~>    Complete_Lattice.Union
    90     Set.INTER ~>    Complete_Lattice.INTER
    91     Set.UNION ~>    Complete_Lattice.UNION
    92   - more convenient names for set intersection and union:
    93     Set.Int ~>      Set.inter
    94     Set.Un ~>       Set.union
    95   - authentic syntax for
    96     Set.Pow
    97     Set.image
    98   - mere abbreviations:
    99     Set.empty               (for bot)
   100     Set.UNIV                (for top)
   101     Set.inter               (for inf)
   102     Set.union               (for sup)
   103     Complete_Lattice.Inter  (for Inf)
   104     Complete_Lattice.Union  (for Sup)
   105     Complete_Lattice.INTER  (for INFI)
   106     Complete_Lattice.UNION  (for SUPR)
   107   - object-logic definitions as far as appropriate
   108 
   109 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   110 Un_subset_iff are explicitly deleted as default simp rules;  then
   111 also their lattice counterparts le_inf_iff and le_sup_iff have to be
   112 deleted to achieve the desired effect.
   113 
   114 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no
   115 simp rules by default any longer.  The same applies to
   116 min_max.inf_absorb1 etc.!  INCOMPATIBILITY.
   117 
   118 * sup_Int_eq and sup_Un_eq are no default pred_set_conv rules any longer.
   119 INCOMPATIBILITY.
   120 
   121 * Power operations on relations and functions are now one dedicate
   122 constant "compow" with infix syntax "^^".  Power operation on
   123 multiplicative monoids retains syntax "^" and is now defined generic
   124 in class power.  INCOMPATIBILITY.
   125 
   126 * Relation composition "R O S" now has a "more standard" argument
   127 order, i.e., "R O S = {(x,z). EX y. (x,y) : R & (y,z) : S }".
   128 INCOMPATIBILITY: Rewrite propositions with "S O R" --> "R O S". Proofs
   129 may occationally break, since the O_assoc rule was not rewritten like
   130 this.  Fix using O_assoc[symmetric].  The same applies to the curried
   131 version "R OO S".
   132 
   133 * ML antiquotation @{code_datatype} inserts definition of a datatype
   134 generated by the code generator; see Predicate.thy for an example.
   135 
   136 * New method "linarith" invokes existing linear arithmetic decision
   137 procedure only.
   138 
   139 * New implementation of quickcheck uses generic code generator;
   140 default generators are provided for all suitable HOL types, records
   141 and datatypes.
   142 
   143 * Renamed theorems:
   144 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   145 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   146 Suc_plus1 -> Suc_eq_plus1
   147 
   148 * Moved theorems:
   149 Wellfounded.in_inv_image -> Relation.in_inv_image
   150 
   151 * New sledgehammer option "Full Types" in Proof General settings menu.
   152 Causes full type information to be output to the ATPs.  This slows
   153 ATPs down considerably but eliminates a source of unsound "proofs"
   154 that fail later.
   155 
   156 * New method metisFT: A version of metis that uses full type information
   157 in order to avoid failures of proof reconstruction.
   158 
   159 * Discontinued ancient tradition to suffix certain ML module names
   160 with "_package", e.g.:
   161 
   162     DatatypePackage ~> Datatype
   163     InductivePackage ~> Inductive
   164 
   165 INCOMPATIBILITY.
   166 
   167 * Discontinued abbreviation "arbitrary" of constant
   168 "undefined". INCOMPATIBILITY, use "undefined" directly.
   169 
   170 * New evaluator "approximate" approximates an real valued term using
   171 the same method as the approximation method.
   172 
   173 * Method "approximate" supports now arithmetic expressions as
   174 boundaries of intervals and implements interval splitting and Taylor
   175 series expansion.
   176 
   177 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   178 the theorems in DERIV_intros assumes composition with an additional
   179 function and matches a variable to the derivative, which has to be
   180 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   181 the derivative of most elementary terms.
   182 
   183 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   184 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   185 
   186 
   187 *** ML ***
   188 
   189 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   190 parallel tactical reasoning.
   191 
   192 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   193 are similar to SUBPROOF, but are slightly more flexible: only the
   194 specified parts of the subgoal are imported into the context, and the
   195 body tactic may introduce new subgoals and schematic variables.
   196 
   197 * Old tactical METAHYPS, which does not observe the proof context, has
   198 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   199 or Subgoal.FOCUS etc.
   200 
   201 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   202 functors have their own ML name space there is no point to mark them
   203 separately.)  Minor INCOMPATIBILITY.
   204 
   205 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   206 
   207 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   208 cominators for "args".  INCOMPATIBILITY, need to use simplified
   209 Attrib/Method.setup introduced in Isabelle2009.
   210 
   211 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   212 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   213 last resort.  INCOMPATIBILITY.
   214 
   215 * Display.pretty_thm now requires a proper context (cf. former
   216 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   217 or even Display.pretty_thm_without_context as last resort.
   218 INCOMPATIBILITY.
   219 
   220 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   221 Syntax.pretty_typ/term directly, preferably with proper context
   222 instead of global theory.
   223 
   224 
   225 *** System ***
   226 
   227 * Support for additional "Isabelle components" via etc/components, see
   228 also the system manual.
   229 
   230 * The isabelle makeall tool now operates on all components with
   231 IsaMakefile, not just hardwired "logics".
   232 
   233 * Discontinued support for Poly/ML 4.x versions.
   234 
   235 * Removed "compress" option from isabelle-process and isabelle usedir;
   236 this is always enabled.
   237 
   238 * More fine-grained control of proof parallelism, cf.
   239 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   240 
   241 
   242 
   243 New in Isabelle2009 (April 2009)
   244 --------------------------------
   245 
   246 *** General ***
   247 
   248 * Simplified main Isabelle executables, with less surprises on
   249 case-insensitive file-systems (such as Mac OS).
   250 
   251   - The main Isabelle tool wrapper is now called "isabelle" instead of
   252     "isatool."
   253 
   254   - The former "isabelle" alias for "isabelle-process" has been
   255     removed (should rarely occur to regular users).
   256 
   257   - The former "isabelle-interface" and its alias "Isabelle" have been
   258     removed (interfaces are now regular Isabelle tools).
   259 
   260 Within scripts and make files, the Isabelle environment variables
   261 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   262 respectively.  (The latter are still available as legacy feature.)
   263 
   264 The old isabelle-interface wrapper could react in confusing ways if
   265 the interface was uninstalled or changed otherwise.  Individual
   266 interface tool configuration is now more explicit, see also the
   267 Isabelle system manual.  In particular, Proof General is now available
   268 via "isabelle emacs".
   269 
   270 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   271 purge installed copies of Isabelle executables and re-run "isabelle
   272 install -p ...", or use symlinks.
   273 
   274 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   275 old ~/isabelle, which was slightly non-standard and apt to cause
   276 surprises on case-insensitive file-systems (such as Mac OS).
   277 
   278 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   279 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   280 care is required when using older releases of Isabelle.  Note that
   281 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   282 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   283 
   284 * Proofs of fully specified statements are run in parallel on
   285 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   286 a regular 4-core machine, if the initial heap space is made reasonably
   287 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   288 
   289 * The main reference manuals ("isar-ref", "implementation", and
   290 "system") have been updated and extended.  Formally checked references
   291 as hyperlinks are now available uniformly.
   292 
   293 
   294 *** Pure ***
   295 
   296 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   297 respects.  The most important changes are listed below.  See the
   298 Tutorial on Locales ("locales" manual) for details.
   299 
   300 - In locale expressions, instantiation replaces renaming.  Parameters
   301 must be declared in a for clause.  To aid compatibility with previous
   302 parameter inheritance, in locale declarations, parameters that are not
   303 'touched' (instantiation position "_" or omitted) are implicitly added
   304 with their syntax at the beginning of the for clause.
   305 
   306 - Syntax from abbreviations and definitions in locales is available in
   307 locale expressions and context elements.  The latter is particularly
   308 useful in locale declarations.
   309 
   310 - More flexible mechanisms to qualify names generated by locale
   311 expressions.  Qualifiers (prefixes) may be specified in locale
   312 expressions, and can be marked as mandatory (syntax: "name!:") or
   313 optional (syntax "name?:").  The default depends for plain "name:"
   314 depends on the situation where a locale expression is used: in
   315 commands 'locale' and 'sublocale' prefixes are optional, in
   316 'interpretation' and 'interpret' prefixes are mandatory.  The old
   317 implicit qualifiers derived from the parameter names of a locale are
   318 no longer generated.
   319 
   320 - Command "sublocale l < e" replaces "interpretation l < e".  The
   321 instantiation clause in "interpretation" and "interpret" (square
   322 brackets) is no longer available.  Use locale expressions.
   323 
   324 - When converting proof scripts, mandatory qualifiers in
   325 'interpretation' and 'interpret' should be retained by default, even
   326 if this is an INCOMPATIBILITY compared to former behavior.  In the
   327 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   328 in locale expressions range over a single locale instance only.
   329 
   330 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   331 In existing theorem specifications replace the includes element by the
   332 respective context elements of the included locale, omitting those
   333 that are already present in the theorem specification.  Multiple
   334 assume elements of a locale should be replaced by a single one
   335 involving the locale predicate.  In the proof body, declarations (most
   336 notably theorems) may be regained by interpreting the respective
   337 locales in the proof context as required (command "interpret").
   338 
   339 If using "includes" in replacement of a target solely because the
   340 parameter types in the theorem are not as general as in the target,
   341 consider declaring a new locale with additional type constraints on
   342 the parameters (context element "constrains").
   343 
   344 - Discontinued "locale (open)".  INCOMPATIBILITY.
   345 
   346 - Locale interpretation commands no longer attempt to simplify goal.
   347 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   348 methods intro_locales and unfold_locales to clarify.
   349 
   350 - Locale interpretation commands no longer accept interpretation
   351 attributes.  INCOMPATIBILITY.
   352 
   353 * Class declaration: so-called "base sort" must not be given in import
   354 list any longer, but is inferred from the specification.  Particularly
   355 in HOL, write
   356 
   357     class foo = ...
   358 
   359 instead of
   360 
   361     class foo = type + ...
   362 
   363 * Class target: global versions of theorems stemming do not carry a
   364 parameter prefix any longer.  INCOMPATIBILITY.
   365 
   366 * Class 'instance' command no longer accepts attached definitions.
   367 INCOMPATIBILITY, use proper 'instantiation' target instead.
   368 
   369 * Recovered hiding of consts, which was accidentally broken in
   370 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   371 makes c inaccessible; consider using ``hide (open) const c'' instead.
   372 
   373 * Slightly more coherent Pure syntax, with updated documentation in
   374 isar-ref manual.  Removed locales meta_term_syntax and
   375 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   376 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   377 directly in regular applications.
   378 
   379 * There is a new syntactic category "float_const" for signed decimal
   380 fractions (e.g. 123.45 or -123.45).
   381 
   382 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   383 interface with 'setup' command instead.
   384 
   385 * Command 'local_setup' is similar to 'setup', but operates on a local
   386 theory context.
   387 
   388 * The 'axiomatization' command now only works within a global theory
   389 context.  INCOMPATIBILITY.
   390 
   391 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   392 hypotheses.  Sorts required in the course of reasoning need to be
   393 covered by the constraints in the initial statement, completed by the
   394 type instance information of the background theory.  Non-trivial sort
   395 hypotheses, which rarely occur in practice, may be specified via
   396 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   397 
   398   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   399 
   400 The result contains an implicit sort hypotheses as before --
   401 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   402 normalization.
   403 
   404 * Generalized Isar history, with support for linear undo, direct state
   405 addressing etc.
   406 
   407 * Changed defaults for unify configuration options:
   408 
   409   unify_trace_bound = 50 (formerly 25)
   410   unify_search_bound = 60 (formerly 30)
   411 
   412 * Different bookkeeping for code equations (INCOMPATIBILITY):
   413 
   414   a) On theory merge, the last set of code equations for a particular
   415      constant is taken (in accordance with the policy applied by other
   416      parts of the code generator framework).
   417 
   418   b) Code equations stemming from explicit declarations (e.g. code
   419      attribute) gain priority over default code equations stemming
   420      from definition, primrec, fun etc.
   421 
   422 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   423 
   424 * Unified theorem tables for both code generators.  Thus [code
   425 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   426 
   427 * Command 'find_consts' searches for constants based on type and name
   428 patterns, e.g.
   429 
   430     find_consts "_ => bool"
   431 
   432 By default, matching is against subtypes, but it may be restricted to
   433 the whole type.  Searching by name is possible.  Multiple queries are
   434 conjunctive and queries may be negated by prefixing them with a
   435 hyphen:
   436 
   437     find_consts strict: "_ => bool" name: "Int" -"int => int"
   438 
   439 * New 'find_theorems' criterion "solves" matches theorems that
   440 directly solve the current goal (modulo higher-order unification).
   441 
   442 * Auto solve feature for main theorem statements: whenever a new goal
   443 is stated, "find_theorems solves" is called; any theorems that could
   444 solve the lemma directly are listed as part of the goal state.
   445 Cf. associated options in Proof General Isabelle settings menu,
   446 enabled by default, with reasonable timeout for pathological cases of
   447 higher-order unification.
   448 
   449 
   450 *** Document preparation ***
   451 
   452 * Antiquotation @{lemma} now imitates a regular terminal proof,
   453 demanding keyword 'by' and supporting the full method expression
   454 syntax just like the Isar command 'by'.
   455 
   456 
   457 *** HOL ***
   458 
   459 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   460 points Main and Complex_Main remain as before.
   461 
   462 * Logic image HOL-Plain provides a minimal HOL with the most important
   463 tools available (inductive, datatype, primrec, ...).  This facilitates
   464 experimentation and tool development.  Note that user applications
   465 (and library theories) should never refer to anything below theory
   466 Main, as before.
   467 
   468 * Logic image HOL-Main stops at theory Main, and thus facilitates
   469 experimentation due to shorter build times.
   470 
   471 * Logic image HOL-NSA contains theories of nonstandard analysis which
   472 were previously part of former HOL-Complex.  Entry point Hyperreal
   473 remains valid, but theories formerly using Complex_Main should now use
   474 new entry point Hypercomplex.
   475 
   476 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   477 Posix processes.  Avoids potentially expensive forking of the ML
   478 process.  New thread-based implementation also works on non-Unix
   479 platforms (Cygwin).  Provers are no longer hardwired, but defined
   480 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   481 commands are covered in the isar-ref manual.
   482 
   483 * Wrapper scripts for remote SystemOnTPTP service allows to use
   484 sledgehammer without local ATP installation (Vampire etc.). Other
   485 provers may be included via suitable ML wrappers, see also
   486 src/HOL/ATP_Linkup.thy.
   487 
   488 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   489 menu.
   490 
   491 * The metis method no longer fails because the theorem is too trivial
   492 (contains the empty clause).
   493 
   494 * The metis method now fails in the usual manner, rather than raising
   495 an exception, if it determines that it cannot prove the theorem.
   496 
   497 * Method "coherent" implements a prover for coherent logic (see also
   498 src/Tools/coherent.ML).
   499 
   500 * Constants "undefined" and "default" replace "arbitrary".  Usually
   501 "undefined" is the right choice to replace "arbitrary", though
   502 logically there is no difference.  INCOMPATIBILITY.
   503 
   504 * Command "value" now integrates different evaluation mechanisms.  The
   505 result of the first successful evaluation mechanism is printed.  In
   506 square brackets a particular named evaluation mechanisms may be
   507 specified (currently, [SML], [code] or [nbe]).  See further
   508 src/HOL/ex/Eval_Examples.thy.
   509 
   510 * Normalization by evaluation now allows non-leftlinear equations.
   511 Declare with attribute [code nbe].
   512 
   513 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   514 as the structured Isar versions "cases" and "induct", cf. the
   515 corresponding "cases" and "induct" attributes.  Mutual induction rules
   516 are now presented as a list of individual projections
   517 (e.g. foo_bar.inducts for types foo and bar); the old format with
   518 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   519 rare situations a different rule is selected --- notably nested tuple
   520 elimination instead of former prod.exhaust: use explicit (case_tac t
   521 rule: prod.exhaust) here.
   522 
   523 * Attributes "cases", "induct", "coinduct" support "del" option.
   524 
   525 * Removed fact "case_split_thm", which duplicates "case_split".
   526 
   527 * The option datatype has been moved to a new theory Option.  Renamed
   528 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   529 
   530 * New predicate "strict_mono" classifies strict functions on partial
   531 orders.  With strict functions on linear orders, reasoning about
   532 (in)equalities is facilitated by theorems "strict_mono_eq",
   533 "strict_mono_less_eq" and "strict_mono_less".
   534 
   535 * Some set operations are now proper qualified constants with
   536 authentic syntax.  INCOMPATIBILITY:
   537 
   538     op Int ~>   Set.Int
   539     op Un ~>    Set.Un
   540     INTER ~>    Set.INTER
   541     UNION ~>    Set.UNION
   542     Inter ~>    Set.Inter
   543     Union ~>    Set.Union
   544     {} ~>       Set.empty
   545     UNIV ~>     Set.UNIV
   546 
   547 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   548 theory Set.
   549 
   550 * Auxiliary class "itself" has disappeared -- classes without any
   551 parameter are treated as expected by the 'class' command.
   552 
   553 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   554 
   555 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   556 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   557 
   558 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   559 method "approximation".  It proves formulas on real values by using
   560 interval arithmetic.  In the formulas are also the transcendental
   561 functions sin, cos, tan, atan, ln, exp and the constant pi are
   562 allowed. For examples see
   563 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   564 
   565 * Theory "Reflection" now resides in HOL/Library.
   566 
   567 * Entry point to Word library now simply named "Word".
   568 INCOMPATIBILITY.
   569 
   570 * Made source layout more coherent with logical distribution
   571 structure:
   572 
   573     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   574     src/HOL/Library/Code_Message.thy ~> src/HOL/
   575     src/HOL/Library/GCD.thy ~> src/HOL/
   576     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   577     src/HOL/Library/Parity.thy ~> src/HOL/
   578     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   579     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   580     src/HOL/Real/Lubs.thy ~> src/HOL/
   581     src/HOL/Real/PReal.thy ~> src/HOL/
   582     src/HOL/Real/Rational.thy ~> src/HOL/
   583     src/HOL/Real/RComplete.thy ~> src/HOL/
   584     src/HOL/Real/RealDef.thy ~> src/HOL/
   585     src/HOL/Real/RealPow.thy ~> src/HOL/
   586     src/HOL/Real/Real.thy ~> src/HOL/
   587     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   588     src/HOL/Complex/Complex.thy ~> src/HOL/
   589     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   590     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   591     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   592     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   593     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   594     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   595     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   596     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   597     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   598     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   599     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   600     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   601     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   602     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   603     src/HOL/Real/Float ~> src/HOL/Library/
   604     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   605     src/HOL/Real/RealVector.thy ~> src/HOL/
   606 
   607     src/HOL/arith_data.ML ~> src/HOL/Tools
   608     src/HOL/hologic.ML ~> src/HOL/Tools
   609     src/HOL/simpdata.ML ~> src/HOL/Tools
   610     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   611     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   612     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   613     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   614     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   615     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   616     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   617 
   618     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   619     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   620     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   621     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   622     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   623     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   624 
   625 * If methods "eval" and "evaluation" encounter a structured proof
   626 state with !!/==>, only the conclusion is evaluated to True (if
   627 possible), avoiding strange error messages.
   628 
   629 * Method "sizechange" automates termination proofs using (a
   630 modification of) the size-change principle.  Requires SAT solver.  See
   631 src/HOL/ex/Termination.thy for examples.
   632 
   633 * Simplifier: simproc for let expressions now unfolds if bound
   634 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   635 
   636 * Method "arith": Linear arithmetic now ignores all inequalities when
   637 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   638 
   639 * New attribute "arith" for facts that should always be used
   640 automatically by arithmetic. It is intended to be used locally in
   641 proofs, e.g.
   642 
   643   assumes [arith]: "x > 0"
   644 
   645 Global usage is discouraged because of possible performance impact.
   646 
   647 * New classes "top" and "bot" with corresponding operations "top" and
   648 "bot" in theory Orderings; instantiation of class "complete_lattice"
   649 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   650 
   651 * Changed definition lemma "less_fun_def" in order to provide an
   652 instance for preorders on functions; use lemma "less_le" instead.
   653 INCOMPATIBILITY.
   654 
   655 * Theory Orderings: class "wellorder" moved here, with explicit
   656 induction rule "less_induct" as assumption.  For instantiation of
   657 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   658 INCOMPATIBILITY.
   659 
   660 * Theory Orderings: added class "preorder" as superclass of "order".
   661 INCOMPATIBILITY: Instantiation proofs for order, linorder
   662 etc. slightly changed.  Some theorems named order_class.* now named
   663 preorder_class.*.
   664 
   665 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   666 "diag" to "Id_on".
   667 
   668 * Theory Finite_Set: added a new fold combinator of type
   669 
   670   ('a => 'b => 'b) => 'b => 'a set => 'b
   671 
   672 Occasionally this is more convenient than the old fold combinator
   673 which is now defined in terms of the new one and renamed to
   674 fold_image.
   675 
   676 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   677 and "ring_simps" have been replaced by "algebra_simps" (which can be
   678 extended with further lemmas!).  At the moment both still exist but
   679 the former will disappear at some point.
   680 
   681 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   682 class recpower.  Type-specific simp rules for various recpower types
   683 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   684 
   685 rat_power_0    -> power_0
   686 rat_power_Suc  -> power_Suc
   687 realpow_0      -> power_0
   688 realpow_Suc    -> power_Suc
   689 complexpow_0   -> power_0
   690 complexpow_Suc -> power_Suc
   691 power_poly_0   -> power_0
   692 power_poly_Suc -> power_Suc
   693 
   694 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   695 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   696 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   697 of lemmas from Divides has been generalized from nat to class
   698 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   699 renames resulting from duplicate elimination:
   700 
   701     dvd_def_mod ~>          dvd_eq_mod_eq_0
   702     zero_dvd_iff ~>         dvd_0_left_iff
   703     dvd_0 ~>                dvd_0_right
   704     DIVISION_BY_ZERO_DIV ~> div_by_0
   705     DIVISION_BY_ZERO_MOD ~> mod_by_0
   706     mult_div ~>             div_mult_self2_is_id
   707     mult_mod ~>             mod_mult_self2_is_0
   708 
   709 * Theory IntDiv: removed many lemmas that are instances of class-based
   710 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   711 rename old lemmas as follows:
   712 
   713 dvd_diff               -> nat_dvd_diff
   714 dvd_zminus_iff         -> dvd_minus_iff
   715 mod_add1_eq            -> mod_add_eq
   716 mod_mult1_eq           -> mod_mult_right_eq
   717 mod_mult1_eq'          -> mod_mult_left_eq
   718 mod_mult_distrib_mod   -> mod_mult_eq
   719 nat_mod_add_left_eq    -> mod_add_left_eq
   720 nat_mod_add_right_eq   -> mod_add_right_eq
   721 nat_mod_div_trivial    -> mod_div_trivial
   722 nat_mod_mod_trivial    -> mod_mod_trivial
   723 zdiv_zadd_self1        -> div_add_self1
   724 zdiv_zadd_self2        -> div_add_self2
   725 zdiv_zmult_self1       -> div_mult_self2_is_id
   726 zdiv_zmult_self2       -> div_mult_self1_is_id
   727 zdvd_triv_left         -> dvd_triv_left
   728 zdvd_triv_right        -> dvd_triv_right
   729 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   730 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   731 zmod_zadd_left_eq      -> mod_add_left_eq
   732 zmod_zadd_right_eq     -> mod_add_right_eq
   733 zmod_zadd_self1        -> mod_add_self1
   734 zmod_zadd_self2        -> mod_add_self2
   735 zmod_zadd1_eq          -> mod_add_eq
   736 zmod_zdiff1_eq         -> mod_diff_eq
   737 zmod_zdvd_zmod         -> mod_mod_cancel
   738 zmod_zmod_cancel       -> mod_mod_cancel
   739 zmod_zmult_self1       -> mod_mult_self2_is_0
   740 zmod_zmult_self2       -> mod_mult_self1_is_0
   741 zmod_1                 -> mod_by_1
   742 zdiv_1                 -> div_by_1
   743 zdvd_abs1              -> abs_dvd_iff
   744 zdvd_abs2              -> dvd_abs_iff
   745 zdvd_refl              -> dvd_refl
   746 zdvd_trans             -> dvd_trans
   747 zdvd_zadd              -> dvd_add
   748 zdvd_zdiff             -> dvd_diff
   749 zdvd_zminus_iff        -> dvd_minus_iff
   750 zdvd_zminus2_iff       -> minus_dvd_iff
   751 zdvd_zmultD            -> dvd_mult_right
   752 zdvd_zmultD2           -> dvd_mult_left
   753 zdvd_zmult_mono        -> mult_dvd_mono
   754 zdvd_0_right           -> dvd_0_right
   755 zdvd_0_left            -> dvd_0_left_iff
   756 zdvd_1_left            -> one_dvd
   757 zminus_dvd_iff         -> minus_dvd_iff
   758 
   759 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   760 
   761 * The real numbers offer decimal input syntax: 12.34 is translated
   762 into 1234/10^2. This translation is not reversed upon output.
   763 
   764 * Theory Library/Polynomial defines an abstract type 'a poly of
   765 univariate polynomials with coefficients of type 'a.  In addition to
   766 the standard ring operations, it also supports div and mod.  Code
   767 generation is also supported, using list-style constructors.
   768 
   769 * Theory Library/Inner_Product defines a class of real_inner for real
   770 inner product spaces, with an overloaded operation inner :: 'a => 'a
   771 => real.  Class real_inner is a subclass of real_normed_vector from
   772 theory RealVector.
   773 
   774 * Theory Library/Product_Vector provides instances for the product
   775 type 'a * 'b of several classes from RealVector and Inner_Product.
   776 Definitions of addition, subtraction, scalar multiplication, norms,
   777 and inner products are included.
   778 
   779 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   780 addition to the field operations, numerals and case syntax are also
   781 supported.
   782 
   783 * Theory Library/Diagonalize provides constructive version of Cantor's
   784 first diagonalization argument.
   785 
   786 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   787 zlcm (for int); carried together from various gcd/lcm developements in
   788 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   789 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   790 may recover tupled syntax as follows:
   791 
   792     hide (open) const gcd
   793     abbreviation gcd where
   794       "gcd == (%(a, b). GCD.gcd a b)"
   795     notation (output)
   796       GCD.gcd ("gcd '(_, _')")
   797 
   798 The same works for lcm, zgcd, zlcm.
   799 
   800 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   801 instantiations for algebraic structures.  Removed some duplicate
   802 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   803 
   804 * ML antiquotation @{code} takes a constant as argument and generates
   805 corresponding code in background and inserts name of the corresponding
   806 resulting ML value/function/datatype constructor binding in place.
   807 All occurrences of @{code} with a single ML block are generated
   808 simultaneously.  Provides a generic and safe interface for
   809 instrumentalizing code generation.  See
   810 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   811 In future you ought to refrain from ad-hoc compiling generated SML
   812 code on the ML toplevel.  Note that (for technical reasons) @{code}
   813 cannot refer to constants for which user-defined serializations are
   814 set.  Refer to the corresponding ML counterpart directly in that
   815 cases.
   816 
   817 * Command 'rep_datatype': instead of theorem names the command now
   818 takes a list of terms denoting the constructors of the type to be
   819 represented as datatype.  The characteristic theorems have to be
   820 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   821 have disappeared in favour of existing ones:
   822 
   823     unit_induct                 ~> unit.induct
   824     prod_induct                 ~> prod.induct
   825     sum_induct                  ~> sum.induct
   826     Suc_Suc_eq                  ~> nat.inject
   827     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   828 
   829 
   830 *** HOL-Algebra ***
   831 
   832 * New locales for orders and lattices where the equivalence relation
   833 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   834 locales use a record structure with field eq for the equivalence.
   835 
   836 * New theory of factorial domains.
   837 
   838 * Units_l_inv and Units_r_inv are now simp rules by default.
   839 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   840 and/or r_inv will now also require deletion of these lemmas.
   841 
   842 * Renamed the following theorems, INCOMPATIBILITY:
   843 
   844 UpperD ~> Upper_memD
   845 LowerD ~> Lower_memD
   846 least_carrier ~> least_closed
   847 greatest_carrier ~> greatest_closed
   848 greatest_Lower_above ~> greatest_Lower_below
   849 one_zero ~> carrier_one_zero
   850 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   851 
   852 
   853 *** HOL-Nominal ***
   854 
   855 * Nominal datatypes can now contain type-variables.
   856 
   857 * Commands 'nominal_inductive' and 'equivariance' work with local
   858 theory targets.
   859 
   860 * Nominal primrec can now works with local theory targets and its
   861 specification syntax now conforms to the general format as seen in
   862 'inductive' etc.
   863 
   864 * Method "perm_simp" honours the standard simplifier attributes
   865 (no_asm), (no_asm_use) etc.
   866 
   867 * The new predicate #* is defined like freshness, except that on the
   868 left hand side can be a set or list of atoms.
   869 
   870 * Experimental command 'nominal_inductive2' derives strong induction
   871 principles for inductive definitions.  In contrast to
   872 'nominal_inductive', which can only deal with a fixed number of
   873 binders, it can deal with arbitrary expressions standing for sets of
   874 atoms to be avoided.  The only inductive definition we have at the
   875 moment that needs this generalisation is the typing rule for Lets in
   876 the algorithm W:
   877 
   878  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   879  -----------------------------------------------------------------
   880          Gamma |- Let x be t1 in t2 : T2
   881 
   882 In this rule one wants to avoid all the binders that are introduced by
   883 "close Gamma T1".  We are looking for other examples where this
   884 feature might be useful.  Please let us know.
   885 
   886 
   887 *** HOLCF ***
   888 
   889 * Reimplemented the simplification procedure for proving continuity
   890 subgoals.  The new simproc is extensible; users can declare additional
   891 continuity introduction rules with the attribute [cont2cont].
   892 
   893 * The continuity simproc now uses a different introduction rule for
   894 solving continuity subgoals on terms with lambda abstractions.  In
   895 some rare cases the new simproc may fail to solve subgoals that the
   896 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   897 Potential INCOMPATIBILITY.
   898 
   899 * Command 'fixrec': specification syntax now conforms to the general
   900 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   901 examples.  INCOMPATIBILITY.
   902 
   903 
   904 *** ZF ***
   905 
   906 * Proof of Zorn's Lemma for partial orders.
   907 
   908 
   909 *** ML ***
   910 
   911 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   912 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   913 depends on multithreading, so timouts will not work before Poly/ML
   914 5.2.1!
   915 
   916 * High-level support for concurrent ML programming, see
   917 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   918 particularly convenient to organize independent functional
   919 computations.  The concept of "synchronized variables" provides a
   920 higher-order interface for components with shared state, avoiding the
   921 delicate details of mutexes and condition variables.  (Requires
   922 Poly/ML 5.2.1 or later.)
   923 
   924 * ML bindings produced via Isar commands are stored within the Isar
   925 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   926 become thread-safe and work with undo as expected (concerning
   927 top-level bindings, not side-effects on global references).
   928 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   929 compiler at runtime; really global bindings need to be given outside a
   930 theory.  (Requires Poly/ML 5.2 or later.)
   931 
   932 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   933 context.  Top-level ML bindings are stored within the proof context in
   934 a purely sequential fashion, disregarding the nested proof structure.
   935 ML bindings introduced by 'ML_prf' are discarded at the end of the
   936 proof.  (Requires Poly/ML 5.2 or later.)
   937 
   938 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   939 and Method.setup, as well as Isar commands 'attribute_setup' and
   940 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   941 existing code accordingly, or use plain 'setup' together with old
   942 Method.add_method.
   943 
   944 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   945 to 'a -> thm, while results are always tagged with an authentic oracle
   946 name.  The Isar command 'oracle' is now polymorphic, no argument type
   947 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   948 accordingly.  Note that extra performance may be gained by producing
   949 the cterm carefully, avoiding slow Thm.cterm_of.
   950 
   951 * Simplified interface for defining document antiquotations via
   952 ThyOutput.antiquotation, ThyOutput.output, and optionally
   953 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   954 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   955 examples.
   956 
   957 * More systematic treatment of long names, abstract name bindings, and
   958 name space operations.  Basic operations on qualified names have been
   959 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   960 Long_Name.append.  Old type bstring has been mostly replaced by
   961 abstract type binding (see structure Binding), which supports precise
   962 qualification by packages and local theory targets, as well as proper
   963 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   964 bstring values into Binding.name, or better pass through abstract
   965 bindings everywhere.  See further src/Pure/General/long_name.ML,
   966 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   967 
   968 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   969 LocalTheory.note etc.) now refer to the *full* internal name, not the
   970 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   971 
   972 * Disposed old type and term read functions (Sign.read_def_typ,
   973 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   974 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   975 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   976 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   977 resort for legacy applications.
   978 
   979 * Disposed old declarations, tactics, tactic combinators that refer to
   980 the simpset or claset of an implicit theory (such as Addsimps,
   981 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   982 embedded ML text, or local_simpset_of with a proper context passed as
   983 explicit runtime argument.
   984 
   985 * Rules and tactics that read instantiations (read_instantiate,
   986 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   987 context, which is required for parsing and type-checking.  Moreover,
   988 the variables are specified as plain indexnames, not string encodings
   989 thereof.  INCOMPATIBILITY.
   990 
   991 * Generic Toplevel.add_hook interface allows to analyze the result of
   992 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   993 for theorem dependency output of transactions resulting in a new
   994 theory state.
   995 
   996 * ML antiquotations: block-structured compilation context indicated by
   997 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   998 
   999   @{binding name}                         - basic name binding
  1000   @{let ?pat = term}                      - term abbreviation (HO matching)
  1001   @{note name = fact}                     - fact abbreviation
  1002   @{thm fact}                             - singleton fact (with attributes)
  1003   @{thms fact}                            - general fact (with attributes)
  1004   @{lemma prop by method}                 - singleton goal
  1005   @{lemma prop by meth1 meth2}            - singleton goal
  1006   @{lemma prop1 ... propN by method}      - general goal
  1007   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1008   @{lemma (open) ...}                     - open derivation
  1009 
  1010 
  1011 *** System ***
  1012 
  1013 * The Isabelle "emacs" tool provides a specific interface to invoke
  1014 Proof General / Emacs, with more explicit failure if that is not
  1015 installed (the old isabelle-interface script silently falls back on
  1016 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1017 installation location of the Proof General distribution.
  1018 
  1019 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1020 the Isabelle process into a JVM/Scala application.  See
  1021 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1022 process wrapper has been discontinued.)
  1023 
  1024 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1025 
  1026 * Various status messages (with exact source position information) are
  1027 emitted, if proper markup print mode is enabled.  This allows
  1028 user-interface components to provide detailed feedback on internal
  1029 prover operations.
  1030 
  1031 
  1032 
  1033 New in Isabelle2008 (June 2008)
  1034 -------------------------------
  1035 
  1036 *** General ***
  1037 
  1038 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1039 and updated, with formally checked references as hyperlinks.
  1040 
  1041 * Theory loader: use_thy (and similar operations) no longer set the
  1042 implicit ML context, which was occasionally hard to predict and in
  1043 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1044 provides a proper context already.
  1045 
  1046 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1047 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1048 'use' within a theory file will do the job.
  1049 
  1050 * Name space merge now observes canonical order, i.e. the second space
  1051 is inserted into the first one, while existing entries in the first
  1052 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1053 swap theory imports.
  1054 
  1055 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1056 INCOMPATIBILITY in identifier syntax etc.
  1057 
  1058 * Outer syntax: string tokens no longer admit escaped white space,
  1059 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1060 white space without escapes.
  1061 
  1062 * Outer syntax: string tokens may contain arbitrary character codes
  1063 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1064 "foo_bar".
  1065 
  1066 
  1067 *** Pure ***
  1068 
  1069 * Context-dependent token translations.  Default setup reverts locally
  1070 fixed variables, and adds hilite markup for undeclared frees.
  1071 
  1072 * Unused theorems can be found using the new command 'unused_thms'.
  1073 There are three ways of invoking it:
  1074 
  1075 (1) unused_thms
  1076      Only finds unused theorems in the current theory.
  1077 
  1078 (2) unused_thms thy_1 ... thy_n -
  1079      Finds unused theorems in the current theory and all of its ancestors,
  1080      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1081 
  1082 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1083      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1084      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1085      their ancestors.
  1086 
  1087 In order to increase the readability of the list produced by
  1088 unused_thms, theorems that have been created by a particular instance
  1089 of a theory command such as 'inductive' or 'function' are considered
  1090 to belong to the same "group", meaning that if at least one theorem in
  1091 this group is used, the other theorems in the same group are no longer
  1092 reported as unused.  Moreover, if all theorems in the group are
  1093 unused, only one theorem in the group is displayed.
  1094 
  1095 Note that proof objects have to be switched on in order for
  1096 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1097 usually the case when using Proof General with the default settings).
  1098 
  1099 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1100 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1101 duplicate fact bindings, or even accidental fact duplications.  Note
  1102 that tools may maintain dynamically scoped facts systematically, using
  1103 PureThy.add_thms_dynamic.
  1104 
  1105 * Command 'hide' now allows to hide from "fact" name space as well.
  1106 
  1107 * Eliminated destructive theorem database, simpset, claset, and
  1108 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1109 update of theories within ML code.
  1110 
  1111 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1112 INCOMPATIBILITY, object-logics depending on former Pure require
  1113 additional setup PureThy.old_appl_syntax_setup; object-logics
  1114 depending on former CPure need to refer to Pure.
  1115 
  1116 * Commands 'use' and 'ML' are now purely functional, operating on
  1117 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1118 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1119 INCOMPATIBILITY.
  1120 
  1121 * Command 'setup': discontinued implicit version with ML reference.
  1122 
  1123 * Instantiation target allows for simultaneous specification of class
  1124 instance operations together with an instantiation proof.
  1125 Type-checking phase allows to refer to class operations uniformly.
  1126 See src/HOL/Complex/Complex.thy for an Isar example and
  1127 src/HOL/Library/Eval.thy for an ML example.
  1128 
  1129 * Indexing of literal facts: be more serious about including only
  1130 facts from the visible specification/proof context, but not the
  1131 background context (locale etc.).  Affects `prop` notation and method
  1132 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1133 situations.
  1134 
  1135 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1136 "(open)" option, which used to expose internal bound variables to the
  1137 proof text.
  1138 
  1139 * Isar statements: removed obsolete case "rule_context".
  1140 INCOMPATIBILITY, better use explicit fixes/assumes.
  1141 
  1142 * Locale proofs: default proof step now includes 'unfold_locales';
  1143 hence 'proof' without argument may be used to unfold locale
  1144 predicates.
  1145 
  1146 
  1147 *** Document preparation ***
  1148 
  1149 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1150 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1151 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1152 spot); renamed link color from "darkblue" to "linkcolor" (default
  1153 value unchanged, can be redefined via \definecolor); no longer sets
  1154 "a4paper" option (unnecessary or even intrusive).
  1155 
  1156 * Antiquotation @{lemma A method} proves proposition A by the given
  1157 method (either a method name or a method name plus (optional) method
  1158 arguments in parentheses) and prints A just like @{prop A}.
  1159 
  1160 
  1161 *** HOL ***
  1162 
  1163 * New primrec package.  Specification syntax conforms in style to
  1164 definition/function/....  No separate induction rule is provided.  The
  1165 "primrec" command distinguishes old-style and new-style specifications
  1166 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1167 When adjusting theories, beware: constants stemming from new-style
  1168 primrec specifications have authentic syntax.
  1169 
  1170 * Metis prover is now an order of magnitude faster, and also works
  1171 with multithreading.
  1172 
  1173 * Metis: the maximum number of clauses that can be produced from a
  1174 theorem is now given by the attribute max_clauses.  Theorems that
  1175 exceed this number are ignored, with a warning printed.
  1176 
  1177 * Sledgehammer no longer produces structured proofs by default. To
  1178 enable, declare [[sledgehammer_full = true]].  Attributes
  1179 reconstruction_modulus, reconstruction_sorts renamed
  1180 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1181 
  1182 * Method "induct_scheme" derives user-specified induction rules
  1183 from well-founded induction and completeness of patterns. This factors
  1184 out some operations that are done internally by the function package
  1185 and makes them available separately.  See
  1186 src/HOL/ex/Induction_Scheme.thy for examples.
  1187 
  1188 * More flexible generation of measure functions for termination
  1189 proofs: Measure functions can be declared by proving a rule of the
  1190 form "is_measure f" and giving it the [measure_function] attribute.
  1191 The "is_measure" predicate is logically meaningless (always true), and
  1192 just guides the heuristic.  To find suitable measure functions, the
  1193 termination prover sets up the goal "is_measure ?f" of the appropriate
  1194 type and generates all solutions by prolog-style backwards proof using
  1195 the declared rules.
  1196 
  1197 This setup also deals with rules like 
  1198 
  1199   "is_measure f ==> is_measure (list_size f)"
  1200 
  1201 which accommodates nested datatypes that recurse through lists.
  1202 Similar rules are predeclared for products and option types.
  1203 
  1204 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1205 
  1206   INCOMPATIBILITIES:
  1207 
  1208   - Definitions of overloaded constants on sets have to be replaced by
  1209     definitions on => and bool.
  1210 
  1211   - Some definitions of overloaded operators on sets can now be proved
  1212     using the definitions of the operators on => and bool.  Therefore,
  1213     the following theorems have been renamed:
  1214 
  1215       subset_def   -> subset_eq
  1216       psubset_def  -> psubset_eq
  1217       set_diff_def -> set_diff_eq
  1218       Compl_def    -> Compl_eq
  1219       Sup_set_def  -> Sup_set_eq
  1220       Inf_set_def  -> Inf_set_eq
  1221       sup_set_def  -> sup_set_eq
  1222       inf_set_def  -> inf_set_eq
  1223 
  1224   - Due to the incompleteness of the HO unification algorithm, some
  1225     rules such as subst may require manual instantiation, if some of
  1226     the unknowns in the rule is a set.
  1227 
  1228   - Higher order unification and forward proofs:
  1229     The proof pattern
  1230 
  1231       have "P (S::'a set)" <...>
  1232       then have "EX S. P S" ..
  1233 
  1234     no longer works (due to the incompleteness of the HO unification
  1235     algorithm) and must be replaced by the pattern
  1236 
  1237       have "EX S. P S"
  1238       proof
  1239         show "P S" <...>
  1240       qed
  1241 
  1242   - Calculational reasoning with subst (or similar rules):
  1243     The proof pattern
  1244 
  1245       have "P (S::'a set)" <...>
  1246       also have "S = T" <...>
  1247       finally have "P T" .
  1248 
  1249     no longer works (for similar reasons as the previous example) and
  1250     must be replaced by something like
  1251 
  1252       have "P (S::'a set)" <...>
  1253       moreover have "S = T" <...>
  1254       ultimately have "P T" by simp
  1255 
  1256   - Tactics or packages written in ML code:
  1257     Code performing pattern matching on types via
  1258 
  1259       Type ("set", [T]) => ...
  1260 
  1261     must be rewritten. Moreover, functions like strip_type or
  1262     binder_types no longer return the right value when applied to a
  1263     type of the form
  1264 
  1265       T1 => ... => Tn => U => bool
  1266 
  1267     rather than
  1268 
  1269       T1 => ... => Tn => U set
  1270 
  1271 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1272 Wellfounded_Relations to theory Wellfounded.
  1273 
  1274 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1275 
  1276 * Class finite no longer treats UNIV as class parameter.  Use class
  1277 enum from theory Library/Enum instead to achieve a similar effect.
  1278 INCOMPATIBILITY.
  1279 
  1280 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1281 and "Cons".  INCOMPATIBILITY.
  1282 
  1283 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1284 Potential INCOMPATIBILITY.
  1285 
  1286 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1287 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1288 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1289 
  1290 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1291 the same name in theory Orderings:
  1292 
  1293   less_trans
  1294   less_linear
  1295   le_imp_less_or_eq
  1296   le_less_trans
  1297   less_le_trans
  1298   less_not_sym
  1299   less_asym
  1300 
  1301 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1302 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1303 and different variable names.
  1304 
  1305 * Library/Option_ord.thy: Canonical order on option type.
  1306 
  1307 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1308 finite maps.
  1309 
  1310 * Library/Countable.thy: Type class for countable types.
  1311 
  1312 * Theory Int: The representation of numerals has changed.  The infix
  1313 operator BIT and the bit datatype with constructors B0 and B1 have
  1314 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1315 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1316 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1317 accordingly.
  1318 
  1319 * Theory Nat: definition of <= and < on natural numbers no longer
  1320 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1321 le_def and less_def have disappeared.  Consider lemmas not_less
  1322 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1323 
  1324 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1325 (whose purpose mainly is for various fold_set functionals) have been
  1326 abandoned in favor of the existing algebraic classes
  1327 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1328 lower_semilattice (resp. upper_semilattice) and linorder.
  1329 INCOMPATIBILITY.
  1330 
  1331 * Theory Transitive_Closure: induct and cases rules now declare proper
  1332 case_names ("base" and "step").  INCOMPATIBILITY.
  1333 
  1334 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1335 lattices.  The form set-specific version is available as
  1336 Inductive.lfp_ordinal_induct_set.
  1337 
  1338 * Renamed theorems "power.simps" to "power_int.simps".
  1339 INCOMPATIBILITY.
  1340 
  1341 * Class semiring_div provides basic abstract properties of semirings
  1342 with division and modulo operations.  Subsumes former class dvd_mod.
  1343 
  1344 * Merged theories IntDef, Numeral and IntArith into unified theory
  1345 Int.  INCOMPATIBILITY.
  1346 
  1347 * Theory Library/Code_Index: type "index" now represents natural
  1348 numbers rather than integers.  INCOMPATIBILITY.
  1349 
  1350 * New class "uminus" with operation "uminus" (split of from class
  1351 "minus" which now only has operation "minus", binary).
  1352 INCOMPATIBILITY.
  1353 
  1354 * Constants "card", "internal_split", "option_map" now with authentic
  1355 syntax.  INCOMPATIBILITY.
  1356 
  1357 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1358 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1359 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1360 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1361 Sup_set_def, le_def, less_def, option_map_def now with object
  1362 equality.  INCOMPATIBILITY.
  1363 
  1364 * Records. Removed K_record, and replaced it by pure lambda term
  1365 %x. c. The simplifier setup is now more robust against eta expansion.
  1366 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1367 
  1368 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1369 
  1370 * Library/ListVector: new theory of arithmetic vector operations.
  1371 
  1372 * Library/Order_Relation: new theory of various orderings as sets of
  1373 pairs.  Defines preorders, partial orders, linear orders and
  1374 well-orders on sets and on types.
  1375 
  1376 
  1377 *** ZF ***
  1378 
  1379 * Renamed some theories to allow to loading both ZF and HOL in the
  1380 same session:
  1381 
  1382   Datatype  -> Datatype_ZF
  1383   Inductive -> Inductive_ZF
  1384   Int       -> Int_ZF
  1385   IntDiv    -> IntDiv_ZF
  1386   Nat       -> Nat_ZF
  1387   List      -> List_ZF
  1388   Main      -> Main_ZF
  1389 
  1390 INCOMPATIBILITY: ZF theories that import individual theories below
  1391 Main might need to be adapted.  Regular theory Main is still
  1392 available, as trivial extension of Main_ZF.
  1393 
  1394 
  1395 *** ML ***
  1396 
  1397 * ML within Isar: antiquotation @{const name} or @{const
  1398 name(typargs)} produces statically-checked Const term.
  1399 
  1400 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1401 (of the same name).  Removed obsolete print command.
  1402 
  1403 * Removed obsolete "use_legacy_bindings" function.
  1404 
  1405 * The ``print mode'' is now a thread-local value derived from a global
  1406 template (the former print_mode reference), thus access becomes
  1407 non-critical.  The global print_mode reference is for session
  1408 management only; user-code should use print_mode_value,
  1409 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1410 
  1411 * Functions system/system_out provide a robust way to invoke external
  1412 shell commands, with propagation of interrupts (requires Poly/ML
  1413 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1414 
  1415 
  1416 *** System ***
  1417 
  1418 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1419 in accordance with Proof General 3.7, which prefers GNU emacs.
  1420 
  1421 * isatool tty runs Isabelle process with plain tty interaction;
  1422 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1423 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1424 
  1425 * isatool browser now works with Cygwin as well, using general
  1426 "javapath" function defined in Isabelle process environment.
  1427 
  1428 * YXML notation provides a simple and efficient alternative to
  1429 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1430 isatool yxml as described in the Isabelle system manual.
  1431 
  1432 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1433 provides general wrapper for managing an Isabelle process in a robust
  1434 fashion, with ``cooked'' output from stdin/stderr.
  1435 
  1436 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1437 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1438 
  1439 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1440 way of changing the user's settings is via
  1441 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1442 script.
  1443 
  1444 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1445 cores of the underlying machine, which is a good starting point for
  1446 optimal performance tuning.  The corresponding usedir option -M allows
  1447 "max" as an alias for "0".  WARNING: does not work on certain versions
  1448 of Mac OS (with Poly/ML 5.1).
  1449 
  1450 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1451 adverse effect of Isabelle flooding interactive front-ends (notably
  1452 ProofGeneral / XEmacs).
  1453 
  1454 
  1455 
  1456 New in Isabelle2007 (November 2007)
  1457 -----------------------------------
  1458 
  1459 *** General ***
  1460 
  1461 * More uniform information about legacy features, notably a
  1462 warning/error of "Legacy feature: ...", depending on the state of the
  1463 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1464 legacy features will disappear eventually.
  1465 
  1466 * Theory syntax: the header format ``theory A = B + C:'' has been
  1467 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1468 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1469 
  1470 * Theory syntax: the old non-Isar theory file format has been
  1471 discontinued altogether.  Note that ML proof scripts may still be used
  1472 with Isar theories; migration is usually quite simple with the ML
  1473 function use_legacy_bindings.  INCOMPATIBILITY.
  1474 
  1475 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1476 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1477 quotes.
  1478 
  1479 * Theory loader: be more serious about observing the static theory
  1480 header specifications (including optional directories), but not the
  1481 accidental file locations of previously successful loads.  The strict
  1482 update policy of former update_thy is now already performed by
  1483 use_thy, so the former has been removed; use_thys updates several
  1484 theories simultaneously, just as 'imports' within a theory header
  1485 specification, but without merging the results.  Potential
  1486 INCOMPATIBILITY: may need to refine theory headers and commands
  1487 ROOT.ML which depend on load order.
  1488 
  1489 * Theory loader: optional support for content-based file
  1490 identification, instead of the traditional scheme of full physical
  1491 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1492 (cf. the system manual).  The new scheme allows to work with
  1493 non-finished theories in persistent session images, such that source
  1494 files may be moved later on without requiring reloads.
  1495 
  1496 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1497 file (with the same base name as the theory) are considered a legacy
  1498 feature, which will disappear eventually. Even now, the theory loader
  1499 no longer maintains dependencies on such files.
  1500 
  1501 * Syntax: the scope for resolving ambiguities via type-inference is
  1502 now limited to individual terms, instead of whole simultaneous
  1503 specifications as before. This greatly reduces the complexity of the
  1504 syntax module and improves flexibility by separating parsing and
  1505 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1506 'fixes' etc.) are required in rare situations.
  1507 
  1508 * Syntax: constants introduced by new-style packages ('definition',
  1509 'abbreviation' etc.) are passed through the syntax module in
  1510 ``authentic mode''. This means that associated mixfix annotations
  1511 really stick to such constants, independently of potential name space
  1512 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1513 trees are represented slightly differently, may need to adapt syntax
  1514 translations accordingly. Use CONST marker in 'translations' and
  1515 @{const_syntax} antiquotation in 'parse_translation' etc.
  1516 
  1517 * Legacy goal package: reduced interface to the bare minimum required
  1518 to keep existing proof scripts running.  Most other user-level
  1519 functions are now part of the OldGoals structure, which is *not* open
  1520 by default (consider isatool expandshort before open OldGoals).
  1521 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1522 these tend to cause confusion about the actual goal (!) context being
  1523 used here, which is not necessarily the same as the_context().
  1524 
  1525 * Command 'find_theorems': supports "*" wild-card in "name:"
  1526 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1527 support a specific search form (see ProofGeneral/CHANGES).
  1528 
  1529 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1530 by default, which means that "prems" (and also "fixed variables") are
  1531 suppressed from proof state output.  Note that the ProofGeneral
  1532 settings mechanism allows to change and save options persistently, but
  1533 older versions of Isabelle will fail to start up if a negative prems
  1534 limit is imposed.
  1535 
  1536 * Local theory targets may be specified by non-nested blocks of
  1537 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1538 contain definitions, theorems etc., including any derived mechanism
  1539 that has been implemented on top of these primitives.  This concept
  1540 generalizes the existing ``theorem (in ...)'' towards more versatility
  1541 and scalability.
  1542 
  1543 * Proof General interface: proper undo of final 'end' command;
  1544 discontinued Isabelle/classic mode (ML proof scripts).
  1545 
  1546 
  1547 *** Document preparation ***
  1548 
  1549 * Added antiquotation @{theory name} which prints the given name,
  1550 after checking that it refers to a valid ancestor theory in the
  1551 current context.
  1552 
  1553 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1554 check the given source text as ML type/structure, printing verbatim.
  1555 
  1556 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1557 "c args == rhs" given in the current context.  (Any number of
  1558 arguments may be given on the LHS.)
  1559 
  1560 
  1561 *** Pure ***
  1562 
  1563 * The 'class' package offers a combination of axclass and locale to
  1564 achieve Haskell-like type classes in Isabelle.  Definitions and
  1565 theorems within a class context produce both relative results (with
  1566 implicit parameters according to the locale context), and polymorphic
  1567 constants with qualified polymorphism (according to the class
  1568 context).  Within the body context of a 'class' target, a separate
  1569 syntax layer ("user space type system") takes care of converting
  1570 between global polymorphic consts and internal locale representation.
  1571 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1572 "isatool doc classes" provides a tutorial.
  1573 
  1574 * Generic code generator framework allows to generate executable
  1575 code for ML and Haskell (including Isabelle classes).  A short usage
  1576 sketch:
  1577 
  1578     internal compilation:
  1579         export_code <list of constants (term syntax)> in SML
  1580     writing SML code to a file:
  1581         export_code <list of constants (term syntax)> in SML <filename>
  1582     writing OCaml code to a file:
  1583         export_code <list of constants (term syntax)> in OCaml <filename>
  1584     writing Haskell code to a bunch of files:
  1585         export_code <list of constants (term syntax)> in Haskell <filename>
  1586 
  1587     evaluating closed propositions to True/False using code generation:
  1588         method ``eval''
  1589 
  1590 Reasonable default setup of framework in HOL.
  1591 
  1592 Theorem attributs for selecting and transforming function equations theorems:
  1593 
  1594     [code fun]:        select a theorem as function equation for a specific constant
  1595     [code fun del]:    deselect a theorem as function equation for a specific constant
  1596     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1597     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1598 
  1599 User-defined serializations (target in {SML, OCaml, Haskell}):
  1600 
  1601     code_const <and-list of constants (term syntax)>
  1602       {(target) <and-list of const target syntax>}+
  1603 
  1604     code_type <and-list of type constructors>
  1605       {(target) <and-list of type target syntax>}+
  1606 
  1607     code_instance <and-list of instances>
  1608       {(target)}+
  1609         where instance ::= <type constructor> :: <class>
  1610 
  1611     code_class <and_list of classes>
  1612       {(target) <and-list of class target syntax>}+
  1613         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1614 
  1615 code_instance and code_class only are effective to target Haskell.
  1616 
  1617 For example usage see src/HOL/ex/Codegenerator.thy and
  1618 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1619 generation from Isabelle/HOL theories is available via "isatool doc
  1620 codegen".
  1621 
  1622 * Code generator: consts in 'consts_code' Isar commands are now
  1623 referred to by usual term syntax (including optional type
  1624 annotations).
  1625 
  1626 * Command 'no_translations' removes translation rules from theory
  1627 syntax.
  1628 
  1629 * Overloaded definitions are now actually checked for acyclic
  1630 dependencies.  The overloading scheme is slightly more general than
  1631 that of Haskell98, although Isabelle does not demand an exact
  1632 correspondence to type class and instance declarations.
  1633 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1634 exotic versions of overloading -- at the discretion of the user!
  1635 
  1636 Polymorphic constants are represented via type arguments, i.e. the
  1637 instantiation that matches an instance against the most general
  1638 declaration given in the signature.  For example, with the declaration
  1639 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1640 as c(nat).  Overloading is essentially simultaneous structural
  1641 recursion over such type arguments.  Incomplete specification patterns
  1642 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1643 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1644 Command 'print_theory' outputs the normalized system of recursive
  1645 equations, see section "definitions".
  1646 
  1647 * Configuration options are maintained within the theory or proof
  1648 context (with name and type bool/int/string), providing a very simple
  1649 interface to a poor-man's version of general context data.  Tools may
  1650 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1651 these values using Config.get etc.  Users may change options via an
  1652 associated attribute of the same name.  This form of context
  1653 declaration works particularly well with commands 'declare' or
  1654 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1655 very easy to avoid global references, which would not observe Isar
  1656 toplevel undo/redo and fail to work with multithreading.
  1657 
  1658 Various global ML references of Pure and HOL have been turned into
  1659 configuration options:
  1660 
  1661   Unify.search_bound		unify_search_bound
  1662   Unify.trace_bound		unify_trace_bound
  1663   Unify.trace_simp		unify_trace_simp
  1664   Unify.trace_types		unify_trace_types
  1665   Simplifier.simp_depth_limit	simp_depth_limit
  1666   Blast.depth_limit		blast_depth_limit
  1667   DatatypeProp.dtK		datatype_distinctness_limit
  1668   fast_arith_neq_limit  	fast_arith_neq_limit
  1669   fast_arith_split_limit	fast_arith_split_limit
  1670 
  1671 * Named collections of theorems may be easily installed as context
  1672 data using the functor NamedThmsFun (see also
  1673 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1674 attributes; there is also a toplevel print command.  This facility is
  1675 just a common case of general context data, which is the preferred way
  1676 for anything more complex than just a list of facts in canonical
  1677 order.
  1678 
  1679 * Isar: command 'declaration' augments a local theory by generic
  1680 declaration functions written in ML.  This enables arbitrary content
  1681 being added to the context, depending on a morphism that tells the
  1682 difference of the original declaration context wrt. the application
  1683 context encountered later on.
  1684 
  1685 * Isar: proper interfaces for simplification procedures.  Command
  1686 'simproc_setup' declares named simprocs (with match patterns, and body
  1687 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1688 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1689 
  1690 * Isar: an extra pair of brackets around attribute declarations
  1691 abbreviates a theorem reference involving an internal dummy fact,
  1692 which will be ignored later --- only the effect of the attribute on
  1693 the background context will persist.  This form of in-place
  1694 declarations is particularly useful with commands like 'declare' and
  1695 'using', for example ``have A using [[simproc a]] by simp''.
  1696 
  1697 * Isar: method "assumption" (and implicit closing of subproofs) now
  1698 takes simple non-atomic goal assumptions into account: after applying
  1699 an assumption as a rule the resulting subgoals are solved by atomic
  1700 assumption steps.  This is particularly useful to finish 'obtain'
  1701 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1702 without referring to the original premise "!!x. P x ==> thesis" in the
  1703 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1704 more permissive.
  1705 
  1706 * Isar: implicit use of prems from the Isar proof context is
  1707 considered a legacy feature.  Common applications like ``have A .''
  1708 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1709 referencing facts explicitly here improves readability and
  1710 maintainability of proof texts.
  1711 
  1712 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1713 the obtained context from the course of reasoning!  For example:
  1714 
  1715   assume "EX x y. A x & B y"   -- "any previous fact"
  1716   then guess x and y by clarify
  1717 
  1718 This technique is potentially adventurous, depending on the facts and
  1719 proof tools being involved here.
  1720 
  1721 * Isar: known facts from the proof context may be specified as literal
  1722 propositions, using ASCII back-quote syntax.  This works wherever
  1723 named facts used to be allowed so far, in proof commands, proof
  1724 methods, attributes etc.  Literal facts are retrieved from the context
  1725 according to unification of type and term parameters.  For example,
  1726 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1727 theorems in the current context, then these are valid literal facts:
  1728 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1729 
  1730 There is also a proof method "fact" which does the same composition
  1731 for explicit goal states, e.g. the following proof texts coincide with
  1732 certain special cases of literal facts:
  1733 
  1734   have "A" by fact                 ==  note `A`
  1735   have "A ==> B" by fact           ==  note `A ==> B`
  1736   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1737   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1738 
  1739 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1740 outer syntax.  Thus symbolic identifiers may be used without
  1741 additional white space in declarations like this: ``assume *: A''.
  1742 
  1743 * Isar: 'print_facts' prints all local facts of the current context,
  1744 both named and unnamed ones.
  1745 
  1746 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1747 
  1748   def x == "t" and y == "u"
  1749 
  1750 * Isar: added command 'unfolding', which is structurally similar to
  1751 'using', but affects both the goal state and facts by unfolding given
  1752 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1753 'unfolded' attribute may be replaced by first-class proof text.
  1754 
  1755 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1756 and command 'unfolding' now all support object-level equalities
  1757 (potentially conditional).  The underlying notion of rewrite rule is
  1758 analogous to the 'rule_format' attribute, but *not* that of the
  1759 Simplifier (which is usually more generous).
  1760 
  1761 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1762 premises of a theorem by n. Useful in conjunction with drule.
  1763 
  1764 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1765 method expression within a sandbox consisting of the first N
  1766 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1767 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1768 simplifies all new goals that emerge from applying rule foo to the
  1769 originally first one.
  1770 
  1771 * Isar: schematic goals are no longer restricted to higher-order
  1772 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1773 expected.
  1774 
  1775 * Isar: the conclusion of a long theorem statement is now either
  1776 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1777 (essentially a disjunction of cases with local parameters and
  1778 assumptions).  The latter allows to express general elimination rules
  1779 adequately; in this notation common elimination rules look like this:
  1780 
  1781   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1782     assumes "EX x. P x"
  1783     obtains x where "P x"
  1784 
  1785   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1786     assumes "A & B"
  1787     obtains A and B
  1788 
  1789   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1790     assumes "A | B"
  1791     obtains
  1792       A
  1793     | B
  1794 
  1795 The subsequent classical rules even refer to the formal "thesis"
  1796 explicitly:
  1797 
  1798   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1799     obtains "~ thesis"
  1800 
  1801   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1802     obtains "thesis ==> something"
  1803 
  1804 The actual proof of an 'obtains' statement is analogous to that of the
  1805 Isar proof element 'obtain', only that there may be several cases.
  1806 Optional case names may be specified in parentheses; these will be
  1807 available both in the present proof and as annotations in the
  1808 resulting rule, for later use with the 'cases' method (cf. attribute
  1809 case_names).
  1810 
  1811 * Isar: the assumptions of a long theorem statement are available as
  1812 "assms" fact in the proof context.  This is more appropriate than the
  1813 (historical) "prems", which refers to all assumptions of the current
  1814 context, including those from the target locale, proof body etc.
  1815 
  1816 * Isar: 'print_statement' prints theorems from the current theory or
  1817 proof context in long statement form, according to the syntax of a
  1818 top-level lemma.
  1819 
  1820 * Isar: 'obtain' takes an optional case name for the local context
  1821 introduction rule (default "that").
  1822 
  1823 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1824 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1825 to occur.
  1826 
  1827 * Pure: syntax "CONST name" produces a fully internalized constant
  1828 according to the current context.  This is particularly useful for
  1829 syntax translations that should refer to internal constant
  1830 representations independently of name spaces.
  1831 
  1832 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1833 instead of "FOO ". This allows multiple binder declarations to coexist
  1834 in the same context.  INCOMPATIBILITY.
  1835 
  1836 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1837 primitive that also works in a locale context (both for constants and
  1838 fixed variables). Type declaration and internal syntactic representation
  1839 of given constants retrieved from the context. Likewise, the
  1840 'no_notation' command allows to remove given syntax annotations from the
  1841 current context.
  1842 
  1843 * Isar/locales: new derived specification elements 'axiomatization',
  1844 'definition', 'abbreviation', which support type-inference, admit
  1845 object-level specifications (equality, equivalence).  See also the
  1846 isar-ref manual.  Examples:
  1847 
  1848   axiomatization
  1849     eq  (infix "===" 50) where
  1850     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1851 
  1852   definition "f x y = x + y + 1"
  1853   definition g where "g x = f x x"
  1854 
  1855   abbreviation
  1856     neq  (infix "=!=" 50) where
  1857     "x =!= y == ~ (x === y)"
  1858 
  1859 These specifications may be also used in a locale context.  Then the
  1860 constants being introduced depend on certain fixed parameters, and the
  1861 constant name is qualified by the locale base name.  An internal
  1862 abbreviation takes care for convenient input and output, making the
  1863 parameters implicit and using the original short name.  See also
  1864 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1865 entities from a monomorphic theory.
  1866 
  1867 Presently, abbreviations are only available 'in' a target locale, but
  1868 not inherited by general import expressions.  Also note that
  1869 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1870 'translations' in common applications.  The "no_abbrevs" print mode
  1871 prevents folding of abbreviations in term output.
  1872 
  1873 Concrete syntax is attached to specified constants in internal form,
  1874 independently of name spaces.  The parse tree representation is
  1875 slightly different -- use 'notation' instead of raw 'syntax', and
  1876 'translations' with explicit "CONST" markup to accommodate this.
  1877 
  1878 * Pure/Isar: unified syntax for new-style specification mechanisms
  1879 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1880 full type inference and dummy patterns ("_").  For example:
  1881 
  1882   definition "K x _ = x"
  1883 
  1884   inductive conj for A B
  1885   where "A ==> B ==> conj A B"
  1886 
  1887 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1888 the current context.  Print mode "no_abbrevs" prevents inversion of
  1889 abbreviations on output.
  1890 
  1891 * Isar/locales: improved parameter handling: use of locales "var" and
  1892 "struct" no longer necessary; - parameter renamings are no longer
  1893 required to be injective.  For example, this allows to define
  1894 endomorphisms as locale endom = homom mult mult h.
  1895 
  1896 * Isar/locales: changed the way locales with predicates are defined.
  1897 Instead of accumulating the specification, the imported expression is
  1898 now an interpretation.  INCOMPATIBILITY: different normal form of
  1899 locale expressions.  In particular, in interpretations of locales with
  1900 predicates, goals repesenting already interpreted fragments are not
  1901 removed automatically.  Use methods `intro_locales' and
  1902 `unfold_locales'; see below.
  1903 
  1904 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1905 provide backward reasoning on locales predicates.  The methods are
  1906 aware of interpretations and discharge corresponding goals.
  1907 `intro_locales' is less aggressive then `unfold_locales' and does not
  1908 unfold predicates to assumptions.
  1909 
  1910 * Isar/locales: the order in which locale fragments are accumulated
  1911 has changed.  This enables to override declarations from fragments due
  1912 to interpretations -- for example, unwanted simp rules.
  1913 
  1914 * Isar/locales: interpretation in theories and proof contexts has been
  1915 extended.  One may now specify (and prove) equations, which are
  1916 unfolded in interpreted theorems.  This is useful for replacing
  1917 defined concepts (constants depending on locale parameters) by
  1918 concepts already existing in the target context.  Example:
  1919 
  1920   interpretation partial_order ["op <= :: [int, int] => bool"]
  1921     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1922 
  1923 Typically, the constant `partial_order.less' is created by a
  1924 definition specification element in the context of locale
  1925 partial_order.
  1926 
  1927 * Method "induct": improved internal context management to support
  1928 local fixes and defines on-the-fly. Thus explicit meta-level
  1929 connectives !!  and ==> are rarely required anymore in inductive goals
  1930 (using object-logic connectives for this purpose has been long
  1931 obsolete anyway). Common proof patterns are explained in
  1932 src/HOL/Induct/Common_Patterns.thy, see also
  1933 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1934 examples.
  1935 
  1936 * Method "induct": improved handling of simultaneous goals. Instead of
  1937 introducing object-level conjunction, the statement is now split into
  1938 several conclusions, while the corresponding symbolic cases are nested
  1939 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1940 see src/HOL/Induct/Common_Patterns.thy, for example.
  1941 
  1942 * Method "induct": mutual induction rules are now specified as a list
  1943 of rule sharing the same induction cases. HOL packages usually provide
  1944 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1945 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1946 mutual induction rules differently, i.e. like this:
  1947 
  1948   (induct rule: foo_bar.inducts)
  1949   (induct set: foo bar)
  1950   (induct pred: foo bar)
  1951   (induct type: foo bar)
  1952 
  1953 The ML function ProjectRule.projections turns old-style rules into the
  1954 new format.
  1955 
  1956 * Method "coinduct": dual of induction, see
  1957 src/HOL/Library/Coinductive_List.thy for various examples.
  1958 
  1959 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1960 considered a legacy feature.
  1961 
  1962 * Attribute "symmetric" produces result with standardized schematic
  1963 variables (index 0).  Potential INCOMPATIBILITY.
  1964 
  1965 * Simplifier: by default the simplifier trace only shows top level
  1966 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1967 default. Thus there is less danger of being flooded by the trace. The
  1968 trace indicates where parts have been suppressed.
  1969   
  1970 * Provers/classical: removed obsolete classical version of elim_format
  1971 attribute; classical elim/dest rules are now treated uniformly when
  1972 manipulating the claset.
  1973 
  1974 * Provers/classical: stricter checks to ensure that supplied intro,
  1975 dest and elim rules are well-formed; dest and elim rules must have at
  1976 least one premise.
  1977 
  1978 * Provers/classical: attributes dest/elim/intro take an optional
  1979 weight argument for the rule (just as the Pure versions).  Weights are
  1980 ignored by automated tools, but determine the search order of single
  1981 rule steps.
  1982 
  1983 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1984 where the body does not mention the bound variable.  Note that dummy
  1985 patterns implicitly depend on their context of bounds, which makes
  1986 "{_. _}" match any set comprehension as expected.  Potential
  1987 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1988 constant "_idtdummy" in the binding position.
  1989 
  1990 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1991 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1992 for example "A -> B" => "Pi A (%_. B)".
  1993 
  1994 * Pure: 'class_deps' command visualizes the subclass relation, using
  1995 the graph browser tool.
  1996 
  1997 * Pure: 'print_theory' now suppresses certain internal declarations by
  1998 default; use '!' option for full details.
  1999 
  2000 
  2001 *** HOL ***
  2002 
  2003 * Method "metis" proves goals by applying the Metis general-purpose
  2004 resolution prover (see also http://gilith.com/software/metis/).
  2005 Examples are in the directory MetisExamples.  WARNING: the
  2006 Isabelle/HOL-Metis integration does not yet work properly with
  2007 multi-threading.
  2008   
  2009 * Command 'sledgehammer' invokes external automatic theorem provers as
  2010 background processes.  It generates calls to the "metis" method if
  2011 successful. These can be pasted into the proof.  Users do not have to
  2012 wait for the automatic provers to return.  WARNING: does not really
  2013 work with multi-threading.
  2014 
  2015 * New "auto_quickcheck" feature tests outermost goal statements for
  2016 potential counter-examples.  Controlled by ML references
  2017 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2018 5000 milliseconds).  Fails silently if statements is outside of
  2019 executable fragment, or any other codgenerator problem occurs.
  2020 
  2021 * New constant "undefined" with axiom "undefined x = undefined".
  2022 
  2023 * Added class "HOL.eq", allowing for code generation with polymorphic
  2024 equality.
  2025 
  2026 * Some renaming of class constants due to canonical name prefixing in
  2027 the new 'class' package:
  2028 
  2029     HOL.abs ~> HOL.abs_class.abs
  2030     HOL.divide ~> HOL.divide_class.divide
  2031     0 ~> HOL.zero_class.zero
  2032     1 ~> HOL.one_class.one
  2033     op + ~> HOL.plus_class.plus
  2034     op - ~> HOL.minus_class.minus
  2035     uminus ~> HOL.minus_class.uminus
  2036     op * ~> HOL.times_class.times
  2037     op < ~> HOL.ord_class.less
  2038     op <= > HOL.ord_class.less_eq
  2039     Nat.power ~> Power.power_class.power
  2040     Nat.size ~> Nat.size_class.size
  2041     Numeral.number_of ~> Numeral.number_class.number_of
  2042     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2043     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2044     Orderings.min ~> Orderings.ord_class.min
  2045     Orderings.max ~> Orderings.ord_class.max
  2046     Divides.op div ~> Divides.div_class.div
  2047     Divides.op mod ~> Divides.div_class.mod
  2048     Divides.op dvd ~> Divides.div_class.dvd
  2049 
  2050 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2051 
  2052 a) User-defined constants using any of the names "plus", "minus",
  2053 "times", "less" or "less_eq". The standard syntax translations for
  2054 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2055 names.
  2056 
  2057 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2058 INCOMPATIBILITY: use more specific names.
  2059 
  2060 c) Permutative equations (e.g. "a + b = b + a")
  2061 Since the change of names also changes the order of terms, permutative
  2062 rewrite rules may get applied in a different order. Experience shows
  2063 that this is rarely the case (only two adaptions in the whole Isabelle
  2064 distribution).  INCOMPATIBILITY: rewrite proofs
  2065 
  2066 d) ML code directly refering to constant names
  2067 This in general only affects hand-written proof tactics, simprocs and
  2068 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2069 Consider using @{const_name} antiquotation.
  2070 
  2071 * New class "default" with associated constant "default".
  2072 
  2073 * Function "sgn" is now overloaded and available on int, real, complex
  2074 (and other numeric types), using class "sgn".  Two possible defs of
  2075 sgn are given as equational assumptions in the classes sgn_if and
  2076 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2077 INCOMPATIBILITY.
  2078 
  2079 * Locale "partial_order" now unified with class "order" (cf. theory
  2080 Orderings), added parameter "less".  INCOMPATIBILITY.
  2081 
  2082 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2083 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2084 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2085 
  2086 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2087 changed order of proof goals in instance proofs.
  2088 
  2089 * The transitivity reasoner for partial and linear orders is set up
  2090 for classes "order" and "linorder".  Instances of the reasoner are available
  2091 in all contexts importing or interpreting the corresponding locales.
  2092 Method "order" invokes the reasoner separately; the reasoner
  2093 is also integrated with the Simplifier as a solver.  Diagnostic
  2094 command 'print_orders' shows the available instances of the reasoner
  2095 in the current context.
  2096 
  2097 * Localized monotonicity predicate in theory "Orderings"; integrated
  2098 lemmas max_of_mono and min_of_mono with this predicate.
  2099 INCOMPATIBILITY.
  2100 
  2101 * Formulation of theorem "dense" changed slightly due to integration
  2102 with new class dense_linear_order.
  2103 
  2104 * Uniform lattice theory development in HOL.
  2105 
  2106     constants "meet" and "join" now named "inf" and "sup"
  2107     constant "Meet" now named "Inf"
  2108 
  2109     classes "meet_semilorder" and "join_semilorder" now named
  2110       "lower_semilattice" and "upper_semilattice"
  2111     class "lorder" now named "lattice"
  2112     class "comp_lat" now named "complete_lattice"
  2113 
  2114     Instantiation of lattice classes allows explicit definitions
  2115     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2116 
  2117   INCOMPATIBILITY.  Theorem renames:
  2118 
  2119     meet_left_le            ~> inf_le1
  2120     meet_right_le           ~> inf_le2
  2121     join_left_le            ~> sup_ge1
  2122     join_right_le           ~> sup_ge2
  2123     meet_join_le            ~> inf_sup_ord
  2124     le_meetI                ~> le_infI
  2125     join_leI                ~> le_supI
  2126     le_meet                 ~> le_inf_iff
  2127     le_join                 ~> ge_sup_conv
  2128     meet_idempotent         ~> inf_idem
  2129     join_idempotent         ~> sup_idem
  2130     meet_comm               ~> inf_commute
  2131     join_comm               ~> sup_commute
  2132     meet_leI1               ~> le_infI1
  2133     meet_leI2               ~> le_infI2
  2134     le_joinI1               ~> le_supI1
  2135     le_joinI2               ~> le_supI2
  2136     meet_assoc              ~> inf_assoc
  2137     join_assoc              ~> sup_assoc
  2138     meet_left_comm          ~> inf_left_commute
  2139     meet_left_idempotent    ~> inf_left_idem
  2140     join_left_comm          ~> sup_left_commute
  2141     join_left_idempotent    ~> sup_left_idem
  2142     meet_aci                ~> inf_aci
  2143     join_aci                ~> sup_aci
  2144     le_def_meet             ~> le_iff_inf
  2145     le_def_join             ~> le_iff_sup
  2146     join_absorp2            ~> sup_absorb2
  2147     join_absorp1            ~> sup_absorb1
  2148     meet_absorp1            ~> inf_absorb1
  2149     meet_absorp2            ~> inf_absorb2
  2150     meet_join_absorp        ~> inf_sup_absorb
  2151     join_meet_absorp        ~> sup_inf_absorb
  2152     distrib_join_le         ~> distrib_sup_le
  2153     distrib_meet_le         ~> distrib_inf_le
  2154 
  2155     add_meet_distrib_left   ~> add_inf_distrib_left
  2156     add_join_distrib_left   ~> add_sup_distrib_left
  2157     is_join_neg_meet        ~> is_join_neg_inf
  2158     is_meet_neg_join        ~> is_meet_neg_sup
  2159     add_meet_distrib_right  ~> add_inf_distrib_right
  2160     add_join_distrib_right  ~> add_sup_distrib_right
  2161     add_meet_join_distribs  ~> add_sup_inf_distribs
  2162     join_eq_neg_meet        ~> sup_eq_neg_inf
  2163     meet_eq_neg_join        ~> inf_eq_neg_sup
  2164     add_eq_meet_join        ~> add_eq_inf_sup
  2165     meet_0_imp_0            ~> inf_0_imp_0
  2166     join_0_imp_0            ~> sup_0_imp_0
  2167     meet_0_eq_0             ~> inf_0_eq_0
  2168     join_0_eq_0             ~> sup_0_eq_0
  2169     neg_meet_eq_join        ~> neg_inf_eq_sup
  2170     neg_join_eq_meet        ~> neg_sup_eq_inf
  2171     join_eq_if              ~> sup_eq_if
  2172 
  2173     mono_meet               ~> mono_inf
  2174     mono_join               ~> mono_sup
  2175     meet_bool_eq            ~> inf_bool_eq
  2176     join_bool_eq            ~> sup_bool_eq
  2177     meet_fun_eq             ~> inf_fun_eq
  2178     join_fun_eq             ~> sup_fun_eq
  2179     meet_set_eq             ~> inf_set_eq
  2180     join_set_eq             ~> sup_set_eq
  2181     meet1_iff               ~> inf1_iff
  2182     meet2_iff               ~> inf2_iff
  2183     meet1I                  ~> inf1I
  2184     meet2I                  ~> inf2I
  2185     meet1D1                 ~> inf1D1
  2186     meet2D1                 ~> inf2D1
  2187     meet1D2                 ~> inf1D2
  2188     meet2D2                 ~> inf2D2
  2189     meet1E                  ~> inf1E
  2190     meet2E                  ~> inf2E
  2191     join1_iff               ~> sup1_iff
  2192     join2_iff               ~> sup2_iff
  2193     join1I1                 ~> sup1I1
  2194     join2I1                 ~> sup2I1
  2195     join1I1                 ~> sup1I1
  2196     join2I2                 ~> sup1I2
  2197     join1CI                 ~> sup1CI
  2198     join2CI                 ~> sup2CI
  2199     join1E                  ~> sup1E
  2200     join2E                  ~> sup2E
  2201 
  2202     is_meet_Meet            ~> is_meet_Inf
  2203     Meet_bool_def           ~> Inf_bool_def
  2204     Meet_fun_def            ~> Inf_fun_def
  2205     Meet_greatest           ~> Inf_greatest
  2206     Meet_lower              ~> Inf_lower
  2207     Meet_set_def            ~> Inf_set_def
  2208 
  2209     Sup_def                 ~> Sup_Inf
  2210     Sup_bool_eq             ~> Sup_bool_def
  2211     Sup_fun_eq              ~> Sup_fun_def
  2212     Sup_set_eq              ~> Sup_set_def
  2213 
  2214     listsp_meetI            ~> listsp_infI
  2215     listsp_meet_eq          ~> listsp_inf_eq
  2216 
  2217     meet_min                ~> inf_min
  2218     join_max                ~> sup_max
  2219 
  2220 * Added syntactic class "size"; overloaded constant "size" now has
  2221 type "'a::size ==> bool"
  2222 
  2223 * Internal reorganisation of `size' of datatypes: size theorems
  2224 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2225 simplification rules by default!); theorems "prod.size" now named
  2226 "*.size".
  2227 
  2228 * Class "div" now inherits from class "times" rather than "type".
  2229 INCOMPATIBILITY.
  2230 
  2231 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2232 Linorder etc.  have disappeared; operations defined in terms of
  2233 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2234 
  2235 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2236 
  2237 * HOL-Word: New extensive library and type for generic, fixed size
  2238 machine words, with arithemtic, bit-wise, shifting and rotating
  2239 operations, reflection into int, nat, and bool lists, automation for
  2240 linear arithmetic (by automatic reflection into nat or int), including
  2241 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2242 arithmetic type classes, supporting automatic simplification of
  2243 numerals on all operations.
  2244 
  2245 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2246 
  2247 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2248 
  2249 * Code generator library theories:
  2250   - Code_Integer represents HOL integers by big integer literals in target
  2251     languages.
  2252   - Code_Char represents HOL characters by character literals in target
  2253     languages.
  2254   - Code_Char_chr like Code_Char, but also offers treatment of character
  2255     codes; includes Code_Integer.
  2256   - Executable_Set allows to generate code for finite sets using lists.
  2257   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2258     denominator).
  2259   - Executable_Real implements a subset of real numbers, namly those
  2260     representable by rational numbers.
  2261   - Efficient_Nat implements natural numbers by integers, which in general will
  2262     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2263     includes Code_Integer.
  2264   - Code_Index provides an additional datatype index which is mapped to
  2265     target-language built-in integers.
  2266   - Code_Message provides an additional datatype message_string which is isomorphic to
  2267     strings; messages are mapped to target-language strings.
  2268 
  2269 * New package for inductive predicates
  2270 
  2271   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2272 
  2273     inductive
  2274       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2275       for z_1 :: U_1 and ... and z_n :: U_m
  2276     where
  2277       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2278     | ...
  2279 
  2280   with full support for type-inference, rather than
  2281 
  2282     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2283 
  2284     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2285     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2286 
  2287     inductive "s z_1 ... z_m"
  2288     intros
  2289       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2290       ...
  2291 
  2292   For backward compatibility, there is a wrapper allowing inductive
  2293   sets to be defined with the new package via
  2294 
  2295     inductive_set
  2296       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2297       for z_1 :: U_1 and ... and z_n :: U_m
  2298     where
  2299       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2300     | ...
  2301 
  2302   or
  2303 
  2304     inductive_set
  2305       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2306       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2307       for z_1 :: U_1 and ... and z_n :: U_m
  2308     where
  2309       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2310     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2311     | ...
  2312 
  2313   if the additional syntax "p ..." is required.
  2314 
  2315   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2316   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2317 
  2318   INCOMPATIBILITIES:
  2319 
  2320   - Since declaration and definition of inductive sets or predicates
  2321     is no longer separated, abbreviations involving the newly
  2322     introduced sets or predicates must be specified together with the
  2323     introduction rules after the 'where' keyword (see above), rather
  2324     than before the actual inductive definition.
  2325 
  2326   - The variables in induction and elimination rules are now
  2327     quantified in the order of their occurrence in the introduction
  2328     rules, rather than in alphabetical order. Since this may break
  2329     some proofs, these proofs either have to be repaired, e.g. by
  2330     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2331     statements of the form
  2332 
  2333       case (rule_i a_i_1 ... a_i_{k_i})
  2334 
  2335     or the old order of quantification has to be restored by explicitly adding
  2336     meta-level quantifiers in the introduction rules, i.e.
  2337 
  2338       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2339 
  2340   - The format of the elimination rules is now
  2341 
  2342       p z_1 ... z_m x_1 ... x_n ==>
  2343         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2344         ==> ... ==> P
  2345 
  2346     for predicates and
  2347 
  2348       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2349         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2350         ==> ... ==> P
  2351 
  2352     for sets rather than
  2353 
  2354       x : s z_1 ... z_m ==>
  2355         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2356         ==> ... ==> P
  2357 
  2358     This may require terms in goals to be expanded to n-tuples
  2359     (e.g. using case_tac or simplification with the split_paired_all
  2360     rule) before the above elimination rule is applicable.
  2361 
  2362   - The elimination or case analysis rules for (mutually) inductive
  2363     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2364     list of rules "p_1_..._p_k.elims" is no longer available.
  2365 
  2366 * New package "function"/"fun" for general recursive functions,
  2367 supporting mutual and nested recursion, definitions in local contexts,
  2368 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2369 for small examples, and the separate tutorial on the function
  2370 package. The old recdef "package" is still available as before, but
  2371 users are encouraged to use the new package.
  2372 
  2373 * Method "lexicographic_order" automatically synthesizes termination
  2374 relations as lexicographic combinations of size measures. 
  2375 
  2376 * Case-expressions allow arbitrary constructor-patterns (including
  2377 "_") and take their order into account, like in functional
  2378 programming.  Internally, this is translated into nested
  2379 case-expressions; missing cases are added and mapped to the predefined
  2380 constant "undefined". In complicated cases printing may no longer show
  2381 the original input but the internal form. Lambda-abstractions allow
  2382 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2383 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2384 variable.
  2385 
  2386 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2387 is an abbreviation for "of_nat :: nat => int". The simplification
  2388 rules for "of_nat" have been changed to work like "int" did
  2389 previously.  Potential INCOMPATIBILITY:
  2390   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2391   - of_nat_diff and of_nat_mult are no longer default simp rules
  2392 
  2393 * Method "algebra" solves polynomial equations over (semi)rings using
  2394 Groebner bases. The (semi)ring structure is defined by locales and the
  2395 tool setup depends on that generic context. Installing the method for
  2396 a specific type involves instantiating the locale and possibly adding
  2397 declarations for computation on the coefficients.  The method is
  2398 already instantiated for natural numbers and for the axiomatic class
  2399 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2400 CALCULEMUS 2007 for the general principles underlying this
  2401 architecture of context-aware proof-tools.
  2402 
  2403 * Method "ferrack" implements quantifier elimination over
  2404 special-purpose dense linear orders using locales (analogous to
  2405 "algebra"). The method is already installed for class
  2406 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2407 rat, etc.
  2408 
  2409 * Former constant "List.op @" now named "List.append".  Use ML
  2410 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2411 circumvent possible incompatibilities when working on ML level.
  2412 
  2413 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2414 
  2415 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2416 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2417 
  2418 * New syntax for Haskell-like list comprehension (input only), eg.
  2419 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2420 
  2421 * The special syntax for function "filter" has changed from [x :
  2422 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2423 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2424 
  2425 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2426 defined on nat only, as an abbreviation for [a..<Suc b]
  2427 INCOMPATIBILITY.
  2428 
  2429 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2430 
  2431 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2432 
  2433 * New lemma collection field_simps (an extension of ring_simps) for
  2434 manipulating (in)equations involving division. Multiplies with all
  2435 denominators that can be proved to be non-zero (in equations) or
  2436 positive/negative (in inequations).
  2437 
  2438 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2439 have been improved and renamed to ring_simps, group_simps and
  2440 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2441 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2442 
  2443 * Theory Library/Commutative_Ring: switched from recdef to function
  2444 package; constants add, mul, pow now curried.  Infix syntax for
  2445 algebraic operations.
  2446 
  2447 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2448 INCOMPATIBILITY.
  2449 
  2450 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2451 INCOMPATIBILITY.
  2452 
  2453 * HOL/records: generalised field-update to take a function on the
  2454 field rather than the new value: r(|A := x|) is translated to A_update
  2455 (K x) r The K-combinator that is internally used is called K_record.
  2456 INCOMPATIBILITY: Usage of the plain update functions has to be
  2457 adapted.
  2458  
  2459 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2460 * x = 0, which are required for a semiring.  Richer structures do not
  2461 inherit from semiring_0 anymore, because this property is a theorem
  2462 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2463 there is more to prove, but this is mostly trivial.
  2464 
  2465 * Class "recpower" is generalized to arbitrary monoids, not just
  2466 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2467 commutativity or semiring properties additionally.
  2468 
  2469 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2470 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2471 better use 'abbreviation'.
  2472 
  2473 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2474 
  2475 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2476 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2477 significant changes for setting up numeral syntax for types:
  2478   - New constants Numeral.pred and Numeral.succ instead
  2479       of former Numeral.bin_pred and Numeral.bin_succ.
  2480   - Use integer operations instead of bin_add, bin_mult and so on.
  2481   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2482   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2483 
  2484 See src/HOL/Integ/IntArith.thy for an example setup.
  2485 
  2486 * Command 'normal_form' computes the normal form of a term that may
  2487 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2488 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2489 heavy-duty computations because the functions are compiled to ML
  2490 first.  Correspondingly, a method "normalization" is provided.  See
  2491 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2492 
  2493 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2494 25 like -->); output depends on the "iff" print_mode, the default is
  2495 "A = B" (with priority 50).
  2496 
  2497 * Relations less (<) and less_eq (<=) are also available on type bool.
  2498 Modified syntax to disallow nesting without explicit parentheses,
  2499 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2500 INCOMPATIBILITY.
  2501 
  2502 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2503 
  2504 * Relation composition operator "op O" now has precedence 75 and binds
  2505 stronger than union and intersection. INCOMPATIBILITY.
  2506 
  2507 * The old set interval syntax "{m..n(}" (and relatives) has been
  2508 removed.  Use "{m..<n}" (and relatives) instead.
  2509 
  2510 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2511 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2512 ``declare [[simproc del: neq]]''.
  2513 
  2514 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2515 True/False.
  2516 
  2517 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2518 
  2519 * Theorem setsum_mult renamed to setsum_right_distrib.
  2520 
  2521 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2522 ``rule'' method.
  2523 
  2524 * Reimplemented methods "sat" and "satx", with several improvements:
  2525 goals no longer need to be stated as "<prems> ==> False", equivalences
  2526 (i.e. "=" on type bool) are handled, variable names of the form
  2527 "lit_<n>" are no longer reserved, significant speedup.
  2528 
  2529 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2530 zChaff is still supported as well.
  2531 
  2532 * 'inductive' and 'datatype': provide projections of mutual rules,
  2533 bundled as foo_bar.inducts;
  2534 
  2535 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2536 Library.
  2537 
  2538 * Library: moved theory Accessible_Part to main HOL.
  2539 
  2540 * Library: added theory Coinductive_List of potentially infinite lists
  2541 as greatest fixed-point.
  2542 
  2543 * Library: added theory AssocList which implements (finite) maps as
  2544 association lists.
  2545 
  2546 * Method "evaluation" solves goals (i.e. a boolean expression)
  2547 efficiently by compiling it to ML.  The goal is "proved" (via an
  2548 oracle) if it evaluates to True.
  2549 
  2550 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2551 also when invoked by the simplifier.  This results in the Simplifier
  2552 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2553 Configuration option fast_arith_split_limit=0 recovers the old
  2554 behavior.
  2555 
  2556 * Support for hex (0x20) and binary (0b1001) numerals.
  2557 
  2558 * New method: reify eqs (t), where eqs are equations for an
  2559 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2560 parameter, computes a term s::'b and a list xs::'a list and proves the
  2561 theorem I xs s = t. This is also known as reification or quoting. The
  2562 resulting theorem is applied to the subgoal to substitute t with I xs
  2563 s.  If t is omitted, the subgoal itself is reified.
  2564 
  2565 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2566 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2567 where f is supposed to be a computable function (in the sense of code
  2568 generattion). The method uses reify to compute s and xs as above then
  2569 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2570 r and finally gets the theorem t = r, which is again applied to the
  2571 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2572 
  2573 * Reflection: Automatic reification now handels binding, an example is
  2574 available in src/HOL/ex/ReflectionEx.thy
  2575 
  2576 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2577 command 'statespace' that is similar to 'record', but introduces an
  2578 abstract specification based on the locale infrastructure instead of
  2579 HOL types.  This leads to extra flexibility in composing state spaces,
  2580 in particular multiple inheritance and renaming of components.
  2581 
  2582 
  2583 *** HOL-Complex ***
  2584 
  2585 * Hyperreal: Functions root and sqrt are now defined on negative real
  2586 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2587 Nonnegativity side conditions have been removed from many lemmas, so
  2588 that more subgoals may now be solved by simplification; potential
  2589 INCOMPATIBILITY.
  2590 
  2591 * Real: new type classes formalize real normed vector spaces and
  2592 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2593 and norm :: 'a => real.
  2594 
  2595 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2596 reals into other types. The overloaded constant Reals :: 'a set is now
  2597 defined as range of_real; potential INCOMPATIBILITY.
  2598 
  2599 * Real: proper support for ML code generation, including 'quickcheck'.
  2600 Reals are implemented as arbitrary precision rationals.
  2601 
  2602 * Hyperreal: Several constants that previously worked only for the
  2603 reals have been generalized, so they now work over arbitrary vector
  2604 spaces. Type annotations may need to be added in some cases; potential
  2605 INCOMPATIBILITY.
  2606 
  2607   Infinitesimal  :: ('a::real_normed_vector) star set
  2608   HFinite        :: ('a::real_normed_vector) star set
  2609   HInfinite      :: ('a::real_normed_vector) star set
  2610   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2611   monad          :: ('a::real_normed_vector) star => 'a star set
  2612   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2613   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2614   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2615   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2616   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2617   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2618   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2619   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2620   sgn            :: 'a::real_normed_vector => 'a
  2621   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2622 
  2623 * Complex: Some complex-specific constants are now abbreviations for
  2624 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2625 hnorm.  Other constants have been entirely removed in favor of the
  2626 polymorphic versions (INCOMPATIBILITY):
  2627 
  2628   approx        <-- capprox
  2629   HFinite       <-- CFinite
  2630   HInfinite     <-- CInfinite
  2631   Infinitesimal <-- CInfinitesimal
  2632   monad         <-- cmonad
  2633   galaxy        <-- cgalaxy
  2634   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2635   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2636   (ns)deriv     <-- (ns)cderiv
  2637 
  2638 
  2639 *** HOL-Algebra ***
  2640 
  2641 * Formalisation of ideals and the quotient construction over rings.
  2642 
  2643 * Order and lattice theory no longer based on records.
  2644 INCOMPATIBILITY.
  2645 
  2646 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2647 greatest_closed.  INCOMPATIBILITY.
  2648 
  2649 * Method algebra is now set up via an attribute.  For examples see
  2650 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2651 of algebraic structures.
  2652 
  2653 * Renamed theory CRing to Ring.
  2654 
  2655 
  2656 *** HOL-Nominal ***
  2657 
  2658 * Substantial, yet incomplete support for nominal datatypes (binding
  2659 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2660 src/HOL/Nominal/Examples.  Prospective users should consult
  2661 http://isabelle.in.tum.de/nominal/
  2662 
  2663 
  2664 *** ML ***
  2665 
  2666 * ML basics: just one true type int, which coincides with IntInf.int
  2667 (even on SML/NJ).
  2668 
  2669 * ML within Isar: antiquotations allow to embed statically-checked
  2670 formal entities in the source, referring to the context available at
  2671 compile-time.  For example:
  2672 
  2673 ML {* @{sort "{zero,one}"} *}
  2674 ML {* @{typ "'a => 'b"} *}
  2675 ML {* @{term "%x. x"} *}
  2676 ML {* @{prop "x == y"} *}
  2677 ML {* @{ctyp "'a => 'b"} *}
  2678 ML {* @{cterm "%x. x"} *}
  2679 ML {* @{cprop "x == y"} *}
  2680 ML {* @{thm asm_rl} *}
  2681 ML {* @{thms asm_rl} *}
  2682 ML {* @{type_name c} *}
  2683 ML {* @{type_syntax c} *}
  2684 ML {* @{const_name c} *}
  2685 ML {* @{const_syntax c} *}
  2686 ML {* @{context} *}
  2687 ML {* @{theory} *}
  2688 ML {* @{theory Pure} *}
  2689 ML {* @{theory_ref} *}
  2690 ML {* @{theory_ref Pure} *}
  2691 ML {* @{simpset} *}
  2692 ML {* @{claset} *}
  2693 ML {* @{clasimpset} *}
  2694 
  2695 The same works for sources being ``used'' within an Isar context.
  2696 
  2697 * ML in Isar: improved error reporting; extra verbosity with
  2698 ML_Context.trace enabled.
  2699 
  2700 * Pure/General/table.ML: the join operations now works via exceptions
  2701 DUP/SAME instead of type option. This is simpler in simple cases, and
  2702 admits slightly more efficient complex applications.
  2703 
  2704 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2705 use Context.generic instead of just theory.
  2706 
  2707 * Pure: datatype Context.generic joins theory/Proof.context and
  2708 provides some facilities for code that works in either kind of
  2709 context, notably GenericDataFun for uniform theory and proof data.
  2710 
  2711 * Pure: simplified internal attribute type, which is now always
  2712 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2713 local (Proof.context) attributes have been discontinued, while
  2714 minimizing code duplication. Thm.rule_attribute and
  2715 Thm.declaration_attribute build canonical attributes; see also structure
  2716 Context for further operations on Context.generic, notably
  2717 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2718 declarations and definitions.
  2719 
  2720 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2721 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2722 init only required for impure data. INCOMPATIBILITY: empty really need
  2723 to be empty (no dependencies on theory content!)
  2724 
  2725 * Pure/kernel: consts certification ignores sort constraints given in
  2726 signature declarations. (This information is not relevant to the
  2727 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2728 potential INCOMPATIBILITY.
  2729 
  2730 * Pure: axiomatic type classes are now purely definitional, with
  2731 explicit proofs of class axioms and super class relations performed
  2732 internally. See Pure/axclass.ML for the main internal interfaces --
  2733 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2734 AxClass.axiomatize_class/classrel/arity supersede
  2735 Sign.add_classes/classrel/arities.
  2736 
  2737 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2738 global/local versions on theory vs. Proof.context have been
  2739 discontinued; Attrib.syntax and Method.syntax have been adapted
  2740 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2741 attributes, methods, etc.
  2742 
  2743 * Pure: several functions of signature "... -> theory -> theory * ..."
  2744 have been reoriented to "... -> theory -> ... * theory" in order to
  2745 allow natural usage in combination with the ||>, ||>>, |-> and
  2746 fold_map combinators.
  2747 
  2748 * Pure: official theorem names (closed derivations) and additional
  2749 comments (tags) are now strictly separate.  Name hints -- which are
  2750 maintained as tags -- may be attached any time without affecting the
  2751 derivation.
  2752 
  2753 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2754 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2755 achieve the old behaviour.
  2756 
  2757 * Pure: the "Goal" constant is now called "prop", supporting a
  2758 slightly more general idea of ``protecting'' meta-level rule
  2759 statements.
  2760 
  2761 * Pure: Logic.(un)varify only works in a global context, which is now
  2762 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2763 Logic.legacy_(un)varify as temporary workaround.
  2764 
  2765 * Pure: structure Name provides scalable operations for generating
  2766 internal variable names, notably Name.variants etc.  This replaces
  2767 some popular functions from term.ML:
  2768 
  2769   Term.variant		->  Name.variant
  2770   Term.variantlist	->  Name.variant_list
  2771   Term.invent_names	->  Name.invent_list
  2772 
  2773 Note that low-level renaming rarely occurs in new code -- operations
  2774 from structure Variable are used instead (see below).
  2775 
  2776 * Pure: structure Variable provides fundamental operations for proper
  2777 treatment of fixed/schematic variables in a context.  For example,
  2778 Variable.import introduces fixes for schematics of given facts and
  2779 Variable.export reverses the effect (up to renaming) -- this replaces
  2780 various freeze_thaw operations.
  2781 
  2782 * Pure: structure Goal provides simple interfaces for
  2783 init/conclude/finish and tactical prove operations (replacing former
  2784 Tactic.prove).  Goal.prove is the canonical way to prove results
  2785 within a given context; Goal.prove_global is a degraded version for
  2786 theory level goals, including a global Drule.standard.  Note that
  2787 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2788 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2789 in a locale context).
  2790 
  2791 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2792 and type checking (Syntax.check_term etc.), with common combinations
  2793 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2794 which are considered legacy and await removal.
  2795 
  2796 * Pure/Syntax: generic interfaces for type unchecking
  2797 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2798 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2799 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2800 available for convenience, but refer to the very same operations using
  2801 a mere theory instead of a full context.
  2802 
  2803 * Isar: simplified treatment of user-level errors, using exception
  2804 ERROR of string uniformly.  Function error now merely raises ERROR,
  2805 without any side effect on output channels.  The Isar toplevel takes
  2806 care of proper display of ERROR exceptions.  ML code may use plain
  2807 handle/can/try; cat_error may be used to concatenate errors like this:
  2808 
  2809   ... handle ERROR msg => cat_error msg "..."
  2810 
  2811 Toplevel ML code (run directly or through the Isar toplevel) may be
  2812 embedded into the Isar toplevel with exception display/debug like
  2813 this:
  2814 
  2815   Isar.toplevel (fn () => ...)
  2816 
  2817 INCOMPATIBILITY, removed special transform_error facilities, removed
  2818 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2819 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2820 -- use plain ERROR instead.
  2821 
  2822 * Isar: theory setup now has type (theory -> theory), instead of a
  2823 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2824 
  2825 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2826 ProofContext.debug/verbose flags.
  2827 
  2828 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2829 theory before entering a proof state.  Transactions now always see a
  2830 quasi-functional intermediate checkpoint, both in interactive and
  2831 batch mode.
  2832 
  2833 * Isar: simplified interfaces for outer syntax.  Renamed
  2834 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2835 OuterSyntax.add_parsers -- this functionality is now included in
  2836 OuterSyntax.command etc.  INCOMPATIBILITY.
  2837 
  2838 * Simplifier: the simpset of a running simplification process now
  2839 contains a proof context (cf. Simplifier.the_context), which is the
  2840 very context that the initial simpset has been retrieved from (by
  2841 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2842 (solver, looper etc.) may depend on arbitrary proof data.
  2843 
  2844 * Simplifier.inherit_context inherits the proof context (plus the
  2845 local bounds) of the current simplification process; any simproc
  2846 etc. that calls the Simplifier recursively should do this!  Removed
  2847 former Simplifier.inherit_bounds, which is already included here --
  2848 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2849 specify an explicit context using Simplifier.context/theory_context.
  2850 
  2851 * Simplifier/Classical Reasoner: more abstract interfaces
  2852 change_simpset/claset for modifying the simpset/claset reference of a
  2853 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2854 INCOMPATIBILITY.
  2855 
  2856 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2857 "Trueprop" etc.
  2858 
  2859 
  2860 *** System ***
  2861 
  2862 * settings: the default heap location within ISABELLE_HOME_USER now
  2863 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2864 Isabelle installations.
  2865 
  2866 * isabelle-process: option -S (secure mode) disables some critical
  2867 operations, notably runtime compilation and evaluation of ML source
  2868 code.
  2869 
  2870 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2871 
  2872 * Support for parallel execution, using native multicore support of
  2873 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2874 independent theories, according to the given theory header
  2875 specifications. The maximum number of worker threads is specified via
  2876 usedir option -M or the "max-threads" setting in Proof General. A
  2877 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2878 to 6 on a 8-core machine.  User-code needs to observe certain
  2879 guidelines for thread-safe programming, see appendix A in the Isar
  2880 Implementation manual.
  2881 
  2882 
  2883 
  2884 New in Isabelle2005 (October 2005)
  2885 ----------------------------------
  2886 
  2887 *** General ***
  2888 
  2889 * Theory headers: the new header syntax for Isar theories is
  2890 
  2891   theory <name>
  2892   imports <theory1> ... <theoryN>
  2893   uses <file1> ... <fileM>
  2894   begin
  2895 
  2896 where the 'uses' part is optional.  The previous syntax
  2897 
  2898   theory <name> = <theory1> + ... + <theoryN>:
  2899 
  2900 will disappear in the next release.  Use isatool fixheaders to convert
  2901 existing theory files.  Note that there is no change in ancient
  2902 non-Isar theories now, but these will disappear soon.
  2903 
  2904 * Theory loader: parent theories can now also be referred to via
  2905 relative and absolute paths.
  2906 
  2907 * Command 'find_theorems' searches for a list of criteria instead of a
  2908 list of constants. Known criteria are: intro, elim, dest, name:string,
  2909 simp:term, and any term. Criteria can be preceded by '-' to select
  2910 theorems that do not match. Intro, elim, dest select theorems that
  2911 match the current goal, name:s selects theorems whose fully qualified
  2912 name contain s, and simp:term selects all simplification rules whose
  2913 lhs match term.  Any other term is interpreted as pattern and selects
  2914 all theorems matching the pattern. Available in ProofGeneral under
  2915 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2916 
  2917   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2918 
  2919 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2920 matching the current goal as introduction rule and not having "HOL."
  2921 in their name (i.e. not being defined in theory HOL).
  2922 
  2923 * Command 'thms_containing' has been discontinued in favour of
  2924 'find_theorems'; INCOMPATIBILITY.
  2925 
  2926 * Communication with Proof General is now 8bit clean, which means that
  2927 Unicode text in UTF-8 encoding may be used within theory texts (both
  2928 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2929 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2930 
  2931   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2932   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2933 
  2934 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2935 Classical Reasoner.  Typical big applications run around 2 times
  2936 faster.
  2937 
  2938 
  2939 *** Document preparation ***
  2940 
  2941 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2942 of raw sources.  Only those symbols that do not require additional
  2943 LaTeX packages (depending on comments in isabellesym.sty) are
  2944 displayed properly, everything else is left verbatim.  isatool display
  2945 and isatool print are used as front ends (these are subject to the
  2946 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2947 
  2948 * Command tags control specific markup of certain regions of text,
  2949 notably folding and hiding.  Predefined tags include "theory" (for
  2950 theory begin and end), "proof" for proof commands, and "ML" for
  2951 commands involving ML code; the additional tags "visible" and
  2952 "invisible" are unused by default.  Users may give explicit tag
  2953 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2954 interpretation of tags is determined by the LaTeX job during document
  2955 preparation: see option -V of isatool usedir, or options -n and -t of
  2956 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2957 \isadroptag.
  2958 
  2959 Several document versions may be produced at the same time via isatool
  2960 usedir (the generated index.html will link all of them).  Typical
  2961 specifications include ''-V document=theory,proof,ML'' to present
  2962 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2963 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2964 these parts without any formal replacement text.  The Isabelle site
  2965 default settings produce ''document'' and ''outline'' versions as
  2966 specified above.
  2967 
  2968 * Several new antiquotations:
  2969 
  2970   @{term_type term} prints a term with its type annotated;
  2971 
  2972   @{typeof term} prints the type of a term;
  2973 
  2974   @{const const} is the same as @{term const}, but checks that the
  2975   argument is a known logical constant;
  2976 
  2977   @{term_style style term} and @{thm_style style thm} print a term or
  2978   theorem applying a "style" to it
  2979 
  2980   @{ML text}
  2981 
  2982 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2983 definitions, equations, inequations etc., 'concl' printing only the
  2984 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2985 to print the specified premise.  TermStyle.add_style provides an ML
  2986 interface for introducing further styles.  See also the "LaTeX Sugar"
  2987 document practical applications.  The ML antiquotation prints
  2988 type-checked ML expressions verbatim.
  2989 
  2990 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2991 and 'text' support optional locale specification '(in loc)', which
  2992 specifies the default context for interpreting antiquotations.  For
  2993 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2994 
  2995 * Option 'locale=NAME' of antiquotations specifies an alternative
  2996 context interpreting the subsequent argument.  For example: @{thm
  2997 [locale=lattice] inf_assoc}.
  2998 
  2999 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3000 a proof context.
  3001 
  3002 * Proper output of antiquotations for theory commands involving a
  3003 proof context (such as 'locale' or 'theorem (in loc) ...').
  3004 
  3005 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3006 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3007 
  3008 * isatool usedir: new option -C (default true) controls whether option
  3009 -D should include a copy of the original document directory; -C false
  3010 prevents unwanted effects such as copying of administrative CVS data.
  3011 
  3012 
  3013 *** Pure ***
  3014 
  3015 * Considerably improved version of 'constdefs' command.  Now performs
  3016 automatic type-inference of declared constants; additional support for
  3017 local structure declarations (cf. locales and HOL records), see also
  3018 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3019 sequential dependencies of definitions within a single 'constdefs'
  3020 section; moreover, the declared name needs to be an identifier.  If
  3021 all fails, consider to fall back on 'consts' and 'defs' separately.
  3022 
  3023 * Improved indexed syntax and implicit structures.  First of all,
  3024 indexed syntax provides a notational device for subscripted
  3025 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3026 expressions.  Secondly, in a local context with structure
  3027 declarations, number indexes \<^sub>n or the empty index (default
  3028 number 1) refer to a certain fixed variable implicitly; option
  3029 show_structs controls printing of implicit structures.  Typical
  3030 applications of these concepts involve record types and locales.
  3031 
  3032 * New command 'no_syntax' removes grammar declarations (and
  3033 translations) resulting from the given syntax specification, which is
  3034 interpreted in the same manner as for the 'syntax' command.
  3035 
  3036 * 'Advanced' translation functions (parse_translation etc.) may depend
  3037 on the signature of the theory context being presently used for
  3038 parsing/printing, see also isar-ref manual.
  3039 
  3040 * Improved 'oracle' command provides a type-safe interface to turn an
  3041 ML expression of type theory -> T -> term into a primitive rule of
  3042 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3043 is already included here); see also FOL/ex/IffExample.thy;
  3044 INCOMPATIBILITY.
  3045 
  3046 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3047 before); "cI" is no longer bound, use "c.intro" instead.
  3048 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3049 axclasses vs. locales.
  3050 
  3051 * Improved internal renaming of symbolic identifiers -- attach primes
  3052 instead of base 26 numbers.
  3053 
  3054 * New flag show_question_marks controls printing of leading question
  3055 marks in schematic variable names.
  3056 
  3057 * In schematic variable names, *any* symbol following \<^isub> or
  3058 \<^isup> is now treated as part of the base name.  For example, the
  3059 following works without printing of awkward ".0" indexes:
  3060 
  3061   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3062     by simp
  3063 
  3064 * Inner syntax includes (*(*nested*) comments*).
  3065 
  3066 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3067 annotations as "(00...)".
  3068 
  3069 * Clear separation of logical types and nonterminals, where the latter
  3070 may only occur in 'syntax' specifications or type abbreviations.
  3071 Before that distinction was only partially implemented via type class
  3072 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3073 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3074 exotic syntax specifications may require further adaption
  3075 (e.g. Cube/Cube.thy).
  3076 
  3077 * Removed obsolete type class "logic", use the top sort {} instead.
  3078 Note that non-logical types should be declared as 'nonterminals'
  3079 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3080 specifications.
  3081 
  3082 * Attributes 'induct' and 'cases': type or set names may now be
  3083 locally fixed variables as well.
  3084 
  3085 * Simplifier: can now control the depth to which conditional rewriting
  3086 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3087 Limit.
  3088 
  3089 * Simplifier: simplification procedures may now take the current
  3090 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3091 interface), which is very useful for calling the Simplifier
  3092 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3093 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3094 low-level mk_simproc no longer applies Logic.varify internally, to
  3095 allow for use in a context of fixed variables.
  3096 
  3097 * thin_tac now works even if the assumption being deleted contains !!
  3098 or ==>.  More generally, erule now works even if the major premise of
  3099 the elimination rule contains !! or ==>.
  3100 
  3101 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3102 
  3103 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3104 from Pure, which contains all common declarations already.  Both
  3105 theories are defined via plain Isabelle/Isar .thy files.
  3106 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3107 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3108 use isatool fixcpure to adapt your theory and ML sources.
  3109 
  3110 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3111 selections of theorems in named facts via index ranges.
  3112 
  3113 * 'print_theorems': in theory mode, really print the difference
  3114 wrt. the last state (works for interactive theory development only),
  3115 in proof mode print all local facts (cf. 'print_facts');
  3116 
  3117 * 'hide': option '(open)' hides only base names.
  3118 
  3119 * More efficient treatment of intermediate checkpoints in interactive
  3120 theory development.
  3121 
  3122 * Code generator is now invoked via code_module (incremental code
  3123 generation) and code_library (modular code generation, ML structures
  3124 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3125 must be quoted when used as identifiers.
  3126 
  3127 * New 'value' command for reading, evaluating and printing terms using
  3128 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3129 quoted when used as identifier.
  3130 
  3131 
  3132 *** Locales ***
  3133 
  3134 * New commands for the interpretation of locale expressions in
  3135 theories (1), locales (2) and proof contexts (3).  These generate
  3136 proof obligations from the expression specification.  After the
  3137 obligations have been discharged, theorems of the expression are added
  3138 to the theory, target locale or proof context.  The synopsis of the
  3139 commands is a follows:
  3140 
  3141   (1) interpretation expr inst
  3142   (2) interpretation target < expr
  3143   (3) interpret expr inst
  3144 
  3145 Interpretation in theories and proof contexts require a parameter
  3146 instantiation of terms from the current context.  This is applied to
  3147 specifications and theorems of the interpreted expression.
  3148 Interpretation in locales only permits parameter renaming through the
  3149 locale expression.  Interpretation is smart in that interpretations
  3150 that are active already do not occur in proof obligations, neither are
  3151 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3152 inspect active interpretations of a particular locale.  For details,
  3153 see the Isar Reference manual.  Examples can be found in
  3154 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3155 
  3156 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3157 'interpret' instead.
  3158 
  3159 * New context element 'constrains' for adding type constraints to
  3160 parameters.
  3161 
  3162 * Context expressions: renaming of parameters with syntax
  3163 redeclaration.
  3164 
  3165 * Locale declaration: 'includes' disallowed.
  3166 
  3167 * Proper static binding of attribute syntax -- i.e. types / terms /
  3168 facts mentioned as arguments are always those of the locale definition
  3169 context, independently of the context of later invocations.  Moreover,
  3170 locale operations (renaming and type / term instantiation) are applied
  3171 to attribute arguments as expected.
  3172 
  3173 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3174 actual attributes; rare situations may require Attrib.attribute to
  3175 embed those attributes into Attrib.src that lack concrete syntax.
  3176 Attribute implementations need to cooperate properly with the static
  3177 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3178 Attrib.XXX_thm etc. already do the right thing without further
  3179 intervention.  Only unusual applications -- such as "where" or "of"
  3180 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3181 on the context and the facts involved -- may have to assign parsed
  3182 values to argument tokens explicitly.
  3183 
  3184 * Changed parameter management in theorem generation for long goal
  3185 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3186 theorem statement in rare situations.
  3187 
  3188 * Locale inspection command 'print_locale' omits notes elements.  Use
  3189 'print_locale!' to have them included in the output.
  3190 
  3191 
  3192 *** Provers ***
  3193 
  3194 * Provers/hypsubst.ML: improved version of the subst method, for
  3195 single-step rewriting: it now works in bound variable contexts. New is
  3196 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3197 rewrite a different subterm than the original subst method, which is
  3198 still available as 'simplesubst'.
  3199 
  3200 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3201 and quasi orders.
  3202 
  3203 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3204 reflexive-transitive closure of relations.
  3205 
  3206 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3207 limit (previously hard-coded with a value of 20) user-definable.
  3208 
  3209 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3210 is peformed already.  Object-logics merely need to finish their
  3211 initial simpset configuration as before.  INCOMPATIBILITY.
  3212 
  3213 
  3214 *** HOL ***
  3215 
  3216 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3217 
  3218   syntax (epsilon)
  3219     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3220 
  3221 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3222 and x-symbol; use option '-m epsilon' to get it actually printed.
  3223 Moreover, the mathematically important symbolic identifier \<epsilon>
  3224 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3225 
  3226 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3227 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3228 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3229 support corresponding Isar calculations.
  3230 
  3231 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3232 instead of ":".
  3233 
  3234 * theory SetInterval: changed the syntax for open intervals:
  3235 
  3236   Old       New
  3237   {..n(}    {..<n}
  3238   {)n..}    {n<..}
  3239   {m..n(}   {m..<n}
  3240   {)m..n}   {m<..n}
  3241   {)m..n(}  {m<..<n}
  3242 
  3243 The old syntax is still supported but will disappear in the next
  3244 release.  For conversion use the following Emacs search and replace
  3245 patterns (these are not perfect but work quite well):
  3246 
  3247   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3248   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3249 
  3250 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3251 equalities in commutative rings; method 'algebra' provides a generic
  3252 interface.
  3253 
  3254 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3255 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3256 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3257 be a tuple pattern.
  3258 
  3259 Some new syntax forms are available:
  3260 
  3261   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3262   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3263   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3264   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3265 
  3266 The latter form "\<Sum>x < k. e" used to be based on a separate
  3267 function "Summation", which has been discontinued.
  3268 
  3269 * theory Finite_Set: in structured induction proofs, the insert case
  3270 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3271 (insert F x)'.
  3272 
  3273 * The 'refute' command has been extended to support a much larger
  3274 fragment of HOL, including axiomatic type classes, constdefs and
  3275 typedefs, inductive datatypes and recursion.
  3276 
  3277 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3278 Requires zChaff with proof generation to be installed.  See
  3279 HOL/ex/SAT_Examples.thy for examples.
  3280 
  3281 * Datatype induction via method 'induct' now preserves the name of the
  3282 induction variable. For example, when proving P(xs::'a list) by
  3283 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3284 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3285 in unstructured proof scripts.
  3286 
  3287 * Reworked implementation of records.  Improved scalability for
  3288 records with many fields, avoiding performance problems for type
  3289 inference. Records are no longer composed of nested field types, but
  3290 of nested extension types. Therefore the record type only grows linear
  3291 in the number of extensions and not in the number of fields.  The
  3292 top-level (users) view on records is preserved.  Potential
  3293 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3294 old record representation. The type generated for a record is called
  3295 <record_name>_ext_type.
  3296 
  3297 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3298 proofs triggered by a record definition or a simproc (if
  3299 quick_and_dirty is enabled).  Definitions of large records can take
  3300 quite long.
  3301 
  3302 New simproc record_upd_simproc for simplification of multiple record
  3303 updates enabled by default.  Moreover, trivial updates are also
  3304 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3305 occasionally, since simplification is more powerful by default.
  3306 
  3307 * typedef: proper support for polymorphic sets, which contain extra
  3308 type-variables in the term.
  3309 
  3310 * Simplifier: automatically reasons about transitivity chains
  3311 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3312 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3313 old proofs break occasionally as simplification may now solve more
  3314 goals than previously.
  3315 
  3316 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3317 present.  Works for all partial orders (class "order"), in particular
  3318 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3319 just like y <= x.
  3320 
  3321 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3322 bound variable or a constant then the let is unfolded.  Otherwise
  3323 first a is simplified to b, and then f b is simplified to g. If
  3324 possible we abstract b from g arriving at "let x = b in h x",
  3325 otherwise we unfold the let and arrive at g.  The simproc can be
  3326 enabled/disabled by the reference use_let_simproc.  Potential
  3327 INCOMPATIBILITY since simplification is more powerful by default.
  3328 
  3329 * Classical reasoning: the meson method now accepts theorems as arguments.
  3330 
  3331 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3332 jobs to provide advice on the provability of subgoals.
  3333 
  3334 * Theory OrderedGroup and Ring_and_Field: various additions and
  3335 improvements to faciliate calculations involving equalities and
  3336 inequalities.
  3337 
  3338 The following theorems have been eliminated or modified
  3339 (INCOMPATIBILITY):
  3340 
  3341   abs_eq             now named abs_of_nonneg
  3342   abs_of_ge_0        now named abs_of_nonneg
  3343   abs_minus_eq       now named abs_of_nonpos
  3344   imp_abs_id         now named abs_of_nonneg
  3345   imp_abs_neg_id     now named abs_of_nonpos
  3346   mult_pos           now named mult_pos_pos
  3347   mult_pos_le        now named mult_nonneg_nonneg
  3348   mult_pos_neg_le    now named mult_nonneg_nonpos
  3349   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3350   mult_neg           now named mult_neg_neg
  3351   mult_neg_le        now named mult_nonpos_nonpos
  3352 
  3353 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3354      
  3355      zero_le_square
  3356      not_square_less_zero 
  3357 
  3358   The following lemmas have been deleted from Real/RealPow:
  3359   
  3360      realpow_zero_zero
  3361      realpow_two
  3362      realpow_less
  3363      zero_le_power
  3364      realpow_two_le
  3365      abs_realpow_two
  3366      realpow_two_abs     
  3367 
  3368 * Theory Parity: added rules for simplifying exponents.
  3369 
  3370 * Theory List:
  3371 
  3372 The following theorems have been eliminated or modified
  3373 (INCOMPATIBILITY):
  3374 
  3375   list_all_Nil       now named list_all.simps(1)
  3376   list_all_Cons      now named list_all.simps(2)
  3377   list_all_conv      now named list_all_iff
  3378   set_mem_eq         now named mem_iff
  3379 
  3380 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3381 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3382 
  3383 
  3384 *** HOL-Complex ***
  3385 
  3386 * Theory RealDef: better support for embedding natural numbers and
  3387 integers in the reals.
  3388 
  3389 The following theorems have been eliminated or modified
  3390 (INCOMPATIBILITY):
  3391 
  3392   exp_ge_add_one_self  now requires no hypotheses
  3393   real_of_int_add      reversed direction of equality (use [symmetric])
  3394   real_of_int_minus    reversed direction of equality (use [symmetric])
  3395   real_of_int_diff     reversed direction of equality (use [symmetric])
  3396   real_of_int_mult     reversed direction of equality (use [symmetric])
  3397 
  3398 * Theory RComplete: expanded support for floor and ceiling functions.
  3399 
  3400 * Theory Ln is new, with properties of the natural logarithm
  3401 
  3402 * Hyperreal: There is a new type constructor "star" for making
  3403 nonstandard types.  The old type names are now type synonyms:
  3404 
  3405   hypreal = real star
  3406   hypnat = nat star
  3407   hcomplex = complex star
  3408 
  3409 * Hyperreal: Many groups of similarly-defined constants have been
  3410 replaced by polymorphic versions (INCOMPATIBILITY):
  3411 
  3412   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3413 
  3414   starset      <-- starsetNat, starsetC
  3415   *s*          <-- *sNat*, *sc*
  3416   starset_n    <-- starsetNat_n, starsetC_n
  3417   *sn*         <-- *sNatn*, *scn*
  3418   InternalSets <-- InternalNatSets, InternalCSets
  3419 
  3420   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3421   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3422   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3423   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3424   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3425 
  3426 * Hyperreal: Many type-specific theorems have been removed in favor of
  3427 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3428 
  3429   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3430   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3431   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3432   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3433   right_minus <-- hypreal_add_minus
  3434   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3435   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3436   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3437   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3438   mult_1_right <-- hcomplex_mult_one_right
  3439   mult_zero_left <-- hcomplex_mult_zero_left
  3440   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3441   right_distrib <-- hypnat_add_mult_distrib2
  3442   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3443   right_inverse <-- hypreal_mult_inverse
  3444   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3445   order_refl <-- {hypreal,hypnat}_le_refl
  3446   order_trans <-- {hypreal,hypnat}_le_trans
  3447   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3448   order_less_le <-- {hypreal,hypnat}_less_le
  3449   linorder_linear <-- {hypreal,hypnat}_le_linear
  3450   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3451   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3452   add_nonneg_nonneg <-- hypreal_le_add_order
  3453 
  3454 * Hyperreal: Separate theorems having to do with type-specific
  3455 versions of constants have been merged into theorems that apply to the
  3456 new polymorphic constants (INCOMPATIBILITY):
  3457 
  3458   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3459   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3460   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3461   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3462   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3463   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3464   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3465   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3466   STAR_diff <-- {STAR,STARC}_diff
  3467   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3468     STARC_hcomplex_of_complex}_image_subset
  3469   starset_n_Un <-- starset{Nat,C}_n_Un
  3470   starset_n_Int <-- starset{Nat,C}_n_Int
  3471   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3472   starset_n_diff <-- starset{Nat,C}_n_diff
  3473   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3474   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3475   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3476   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3477   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3478   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3479   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3480   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3481   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3482   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3483   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3484   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3485   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3486   starfun_diff <-- starfun{C,RC,CR}_diff
  3487   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3488   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3489   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3490   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3491   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3492   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3493   starfun_Id <-- starfunC_Id
  3494   starfun_approx <-- starfun{Nat,CR}_approx
  3495   starfun_capprox <-- starfun{C,RC}_capprox
  3496   starfun_abs <-- starfunNat_rabs
  3497   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3498   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3499   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3500   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3501   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3502   starfun_add_approx <-- starfunCR_add_approx
  3503   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3504   starfun_divide <-- starfun{C,CR,RC}_divide
  3505   starfun_n <-- starfun{Nat,C}_n
  3506   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3507   starfun_n_add <-- starfun{Nat,C}_n_add
  3508   starfun_n_add_minus <-- starfunNat_n_add_minus
  3509   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3510   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3511   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3512 
  3513   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3514   star_n_minus <-- {hypreal,hcomplex}_minus
  3515   star_n_diff <-- {hypreal,hcomplex}_diff
  3516   star_n_mult <-- {hypreal,hcomplex}_mult
  3517   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3518   star_n_le <-- {hypreal,hypnat}_le
  3519   star_n_less <-- {hypreal,hypnat}_less
  3520   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3521   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3522   star_n_abs <-- hypreal_hrabs
  3523   star_n_divide <-- hcomplex_divide
  3524 
  3525   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3526   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3527   star_of_diff <-- hypreal_of_real_diff
  3528   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3529   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3530   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3531   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3532   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3533   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3534   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3535   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3536   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3537   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3538   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3539   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3540   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3541   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3542   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3543   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3544   star_of_power <-- hypreal_of_real_power
  3545   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3546 
  3547 * Hyperreal: new method "transfer" that implements the transfer
  3548 principle of nonstandard analysis. With a subgoal that mentions
  3549 nonstandard types like "'a star", the command "apply transfer"
  3550 replaces it with an equivalent one that mentions only standard types.
  3551 To be successful, all free variables must have standard types; non-
  3552 standard variables must have explicit universal quantifiers.
  3553 
  3554 * Hyperreal: A theory of Taylor series.
  3555 
  3556 
  3557 *** HOLCF ***
  3558 
  3559 * Discontinued special version of 'constdefs' (which used to support
  3560 continuous functions) in favor of the general Pure one with full
  3561 type-inference.
  3562 
  3563 * New simplification procedure for solving continuity conditions; it
  3564 is much faster on terms with many nested lambda abstractions (cubic
  3565 instead of exponential time).
  3566 
  3567 * New syntax for domain package: selector names are now optional.
  3568 Parentheses should be omitted unless argument is lazy, for example:
  3569 
  3570   domain 'a stream = cons "'a" (lazy "'a stream")
  3571 
  3572 * New command 'fixrec' for defining recursive functions with pattern
  3573 matching; defining multiple functions with mutual recursion is also
  3574 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3575 sinr, or any data constructor defined by the domain package. The given
  3576 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3577 syntax and examples.
  3578 
  3579 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3580 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3581 but the proof obligation additionally includes an admissibility
  3582 requirement. The packages generate instances of class cpo or pcpo,
  3583 with continuity and strictness theorems for Rep and Abs.
  3584 
  3585 * HOLCF: Many theorems have been renamed according to a more standard naming
  3586 scheme (INCOMPATIBILITY):
  3587 
  3588   foo_inject:  "foo$x = foo$y ==> x = y"
  3589   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3590   foo_less:    "(foo$x << foo$y) = (x << y)"
  3591   foo_strict:  "foo$UU = UU"
  3592   foo_defined: "... ==> foo$x ~= UU"
  3593   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3594 
  3595 
  3596 *** ZF ***
  3597 
  3598 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3599 including the First Isomorphism Theorem (on quotienting by the kernel
  3600 of a homomorphism).
  3601 
  3602 * ZF/Simplifier: install second copy of type solver that actually
  3603 makes use of TC rules declared to Isar proof contexts (or locales);
  3604 the old version is still required for ML proof scripts.
  3605 
  3606 
  3607 *** Cube ***
  3608 
  3609 * Converted to Isar theory format; use locales instead of axiomatic
  3610 theories.
  3611 
  3612 
  3613 *** ML ***
  3614 
  3615 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3616 for ||>, ||>>, |>>,
  3617 
  3618 * Pure/library.ML no longer defines its own option datatype, but uses
  3619 that of the SML basis, which has constructors NONE and SOME instead of
  3620 None and Some, as well as exception Option.Option instead of OPTION.
  3621 The functions the, if_none, is_some, is_none have been adapted
  3622 accordingly, while Option.map replaces apsome.
  3623 
  3624 * Pure/library.ML: the exception LIST has been given up in favour of
  3625 the standard exceptions Empty and Subscript, as well as
  3626 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3627 superceded by the standard hd and tl functions etc.
  3628 
  3629 A number of basic list functions are no longer exported to the ML
  3630 toplevel, as they are variants of predefined functions.  The following
  3631 suggests how one can translate existing code:
  3632 
  3633     rev_append xs ys = List.revAppend (xs, ys)
  3634     nth_elem (i, xs) = List.nth (xs, i)
  3635     last_elem xs = List.last xs
  3636     flat xss = List.concat xss
  3637     seq fs = List.app fs
  3638     partition P xs = List.partition P xs
  3639     mapfilter f xs = List.mapPartial f xs
  3640 
  3641 * Pure/library.ML: several combinators for linear functional
  3642 transformations, notably reverse application and composition:
  3643 
  3644   x |> f                f #> g
  3645   (x, y) |-> f          f #-> g
  3646 
  3647 * Pure/library.ML: introduced/changed precedence of infix operators:
  3648 
  3649   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3650   infix 2 ?;
  3651   infix 3 o oo ooo oooo;
  3652   infix 4 ~~ upto downto;
  3653 
  3654 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3655 infix operators.
  3656 
  3657 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3658 fold_map support linear functional transformations and nesting.  For
  3659 example:
  3660 
  3661   fold f [x1, ..., xN] y =
  3662     y |> f x1 |> ... |> f xN
  3663 
  3664   (fold o fold) f [xs1, ..., xsN] y =
  3665     y |> fold f xs1 |> ... |> fold f xsN
  3666 
  3667   fold f [x1, ..., xN] =
  3668     f x1 #> ... #> f xN
  3669 
  3670   (fold o fold) f [xs1, ..., xsN] =
  3671     fold f xs1 #> ... #> fold f xsN
  3672 
  3673 * Pure/library.ML: the following selectors on type 'a option are
  3674 available:
  3675 
  3676   the:               'a option -> 'a  (*partial*)
  3677   these:             'a option -> 'a  where 'a = 'b list
  3678   the_default: 'a -> 'a option -> 'a
  3679   the_list:          'a option -> 'a list
  3680 
  3681 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3682 basic operations for association lists, following natural argument
  3683 order; moreover the explicit equality predicate passed here avoids
  3684 potentially expensive polymorphic runtime equality checks.
  3685 The old functions may be expressed as follows:
  3686 
  3687   assoc = uncurry (AList.lookup (op =))
  3688   assocs = these oo AList.lookup (op =)
  3689   overwrite = uncurry (AList.update (op =)) o swap
  3690 
  3691 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3692 
  3693   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3694   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3695 
  3696 replacing make_keylist and keyfilter (occassionally used)
  3697 Naive rewrites:
  3698 
  3699   make_keylist = AList.make
  3700   keyfilter = AList.find (op =)
  3701 
  3702 * eq_fst and eq_snd now take explicit equality parameter, thus
  3703   avoiding eqtypes. Naive rewrites:
  3704 
  3705     eq_fst = eq_fst (op =)
  3706     eq_snd = eq_snd (op =)
  3707 
  3708 * Removed deprecated apl and apr (rarely used).
  3709   Naive rewrites:
  3710 
  3711     apl (n, op) =>>= curry op n
  3712     apr (op, m) =>>= fn n => op (n, m)
  3713 
  3714 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3715 provides a reasonably efficient light-weight implementation of sets as
  3716 lists.
  3717 
  3718 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3719 few new operations; existing lookup and update are now curried to
  3720 follow natural argument order (for use with fold etc.);
  3721 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3722 
  3723 * Pure/General: output via the Isabelle channels of
  3724 writeln/warning/error etc. is now passed through Output.output, with a
  3725 hook for arbitrary transformations depending on the print_mode
  3726 (cf. Output.add_mode -- the first active mode that provides a output
  3727 function wins).  Already formatted output may be embedded into further
  3728 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3729 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3730 accommodate easy composition of diagnostic messages etc.  Programmers
  3731 rarely need to care about Output.output or Output.raw at all, with
  3732 some notable exceptions: Output.output is required when bypassing the
  3733 standard channels (writeln etc.), or in token translations to produce
  3734 properly formatted results; Output.raw is required when capturing
  3735 already output material that will eventually be presented to the user
  3736 a second time.  For the default print mode, both Output.output and
  3737 Output.raw have no effect.
  3738 
  3739 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3740 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3741 cumulative results are displayed at the end of a batch session.
  3742 
  3743 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3744 replaced by File.platform_path and File.shell_path (with appropriate
  3745 hooks).  This provides a clean interface for unusual systems where the
  3746 internal and external process view of file names are different.
  3747 
  3748 * Pure: more efficient orders for basic syntactic entities: added
  3749 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3750 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3751 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3752 orders now -- potential INCOMPATIBILITY for code that depends on a
  3753 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3754 Library.sort_strings on result).
  3755 
  3756 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3757 fold_types traverse types/terms from left to right, observing natural
  3758 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3759 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3760 
  3761 * Pure: name spaces have been refined, with significant changes of the
  3762 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3763 to extern(_table).  The plain name entry path is superceded by a
  3764 general 'naming' context, which also includes the 'policy' to produce
  3765 a fully qualified name and external accesses of a fully qualified
  3766 name; NameSpace.extend is superceded by context dependent
  3767 Sign.declare_name.  Several theory and proof context operations modify
  3768 the naming context.  Especially note Theory.restore_naming and
  3769 ProofContext.restore_naming to get back to a sane state; note that
  3770 Theory.add_path is no longer sufficient to recover from
  3771 Theory.absolute_path in particular.
  3772 
  3773 * Pure: new flags short_names (default false) and unique_names
  3774 (default true) for controlling output of qualified names.  If
  3775 short_names is set, names are printed unqualified.  If unique_names is
  3776 reset, the name prefix is reduced to the minimum required to achieve
  3777 the original result when interning again, even if there is an overlap
  3778 with earlier declarations.
  3779 
  3780 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3781 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3782 (useful for printing error messages).  INCOMPATIBILITY.
  3783 
  3784 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3785 Theory.theory are now identified, referring to the universal
  3786 Context.theory (see Pure/context.ML).  Actual signature and theory
  3787 content is managed as theory data.  The old code and interfaces were
  3788 spread over many files and structures; the new arrangement introduces
  3789 considerable INCOMPATIBILITY to gain more clarity:
  3790 
  3791   Context -- theory management operations (name, identity, inclusion,
  3792     parents, ancestors, merge, etc.), plus generic theory data;
  3793 
  3794   Sign -- logical signature and syntax operations (declaring consts,
  3795     types, etc.), plus certify/read for common entities;
  3796 
  3797   Theory -- logical theory operations (stating axioms, definitions,
  3798     oracles), plus a copy of logical signature operations (consts,
  3799     types, etc.); also a few basic management operations (Theory.copy,
  3800     Theory.merge, etc.)
  3801 
  3802 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3803 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3804 for convenience -- they merely return the theory.
  3805 
  3806 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3807 
  3808 * Pure: the Isar proof context type is already defined early in Pure
  3809 as Context.proof (note that ProofContext.context and Proof.context are
  3810 aliases, where the latter is the preferred name).  This enables other
  3811 Isabelle components to refer to that type even before Isar is present.
  3812 
  3813 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3814 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3815 any of these kinds.  For example, Sign.intern typeK is now
  3816 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3817 Theory.hide_types.  Also note that former
  3818 Theory.hide_classes/types/consts are now
  3819 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3820 internalize their arguments!  INCOMPATIBILITY.
  3821 
  3822 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3823 datatype thmref (with constructors Name and NameSelection) instead of
  3824 plain string -- INCOMPATIBILITY;
  3825 
  3826 * Pure: cases produced by proof methods specify options, where NONE
  3827 means to remove case bindings -- INCOMPATIBILITY in
  3828 (RAW_)METHOD_CASES.
  3829 
  3830 * Pure: the following operations retrieve axioms or theorems from a
  3831 theory node or theory hierarchy, respectively:
  3832 
  3833   Theory.axioms_of: theory -> (string * term) list
  3834   Theory.all_axioms_of: theory -> (string * term) list
  3835   PureThy.thms_of: theory -> (string * thm) list
  3836   PureThy.all_thms_of: theory -> (string * thm) list
  3837 
  3838 * Pure: print_tac now outputs the goal through the trace channel.
  3839 
  3840 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3841 Reference Toplevel.debug (default false) controls detailed printing
  3842 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3843 controls execution profiling -- set to 1 for time and 2 for space
  3844 (both increase the runtime).
  3845 
  3846 * Isar session: The initial use of ROOT.ML is now always timed,
  3847 i.e. the log will show the actual process times, in contrast to the
  3848 elapsed wall-clock time that the outer shell wrapper produces.
  3849 
  3850 * Simplifier: improved handling of bound variables (nameless
  3851 representation, avoid allocating new strings).  Simprocs that invoke
  3852 the Simplifier recursively should use Simplifier.inherit_bounds to
  3853 avoid local name clashes.  Failure to do so produces warnings
  3854 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3855 for further details.
  3856 
  3857 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3858 bindings for all theorems stored within a given theory; this may help
  3859 in porting non-Isar theories to Isar ones, while keeping ML proof
  3860 scripts for the time being.
  3861 
  3862 * ML operator HTML.with_charset specifies the charset begin used for
  3863 generated HTML files.  For example:
  3864 
  3865   HTML.with_charset "utf-8" use_thy "Hebrew";
  3866   HTML.with_charset "utf-8" use_thy "Chinese";
  3867 
  3868 
  3869 *** System ***
  3870 
  3871 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3872 isabelle, isatool etc.).
  3873 
  3874 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3875 isatool doc, isatool mkdir, display_drafts etc.).
  3876 
  3877 * isatool usedir: option -f allows specification of the ML file to be
  3878 used by Isabelle; default is ROOT.ML.
  3879 
  3880 * New isatool version outputs the version identifier of the Isabelle
  3881 distribution being used.
  3882 
  3883 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3884 (containing Boolean satisfiability problems) into Isabelle/HOL
  3885 theories.
  3886 
  3887 
  3888 
  3889 New in Isabelle2004 (April 2004)
  3890 --------------------------------
  3891 
  3892 *** General ***
  3893 
  3894 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3895   Replaces linorder.ML.
  3896 
  3897 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3898   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3899   (\<a>...\<z>), are now considered normal letters, and can therefore
  3900   be used anywhere where an ASCII letter (a...zA...Z) has until
  3901   now. COMPATIBILITY: This obviously changes the parsing of some
  3902   terms, especially where a symbol has been used as a binder, say
  3903   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3904   as an identifier.  Fix it by inserting a space around former
  3905   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3906   existing theory and ML files.
  3907 
  3908 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3909 
  3910 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3911   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3912   a normal (but invisible) letter. For multiple letter subscripts repeat
  3913   \<^isub> like this: x\<^isub>1\<^isub>2.
  3914 
  3915 * Pure: There are now sub-/superscripts that can span more than one
  3916   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3917   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3918   superscript. The new control characters are not identifier parts.
  3919 
  3920 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3921   content of "..." to the latex file instead of \isacntrl... . The "..."
  3922   may consist of any printable characters excluding the end bracket >.
  3923 
  3924 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3925   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3926   declare constants "final", which prevents their being given a definition
  3927   later.  It is useful for constants whose behaviour is fixed axiomatically
  3928   rather than definitionally, such as the meta-logic connectives.
  3929 
  3930 * Pure: 'instance' now handles general arities with general sorts
  3931   (i.e. intersections of classes),
  3932 
  3933 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3934   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3935   It can be changed to alter the colors/layout of generated pages.
  3936 
  3937 
  3938 *** Isar ***
  3939 
  3940 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3941   cut_tac, subgoal_tac and thin_tac:
  3942   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3943     locales are no longer forced to write Isar proof scripts.
  3944     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3945     emulations.
  3946   - INCOMPATIBILITY: names of variables to be instantiated may no
  3947     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3948     This is consistent with the instantiation attribute "where".
  3949 
  3950 * Attributes "where" and "of":
  3951   - Now take type variables of instantiated theorem into account when reading
  3952     the instantiation string.  This fixes a bug that caused instantiated
  3953     theorems to have too special types in some circumstances.
  3954   - "where" permits explicit instantiations of type variables.
  3955 
  3956 * Calculation commands "moreover" and "also" no longer interfere with
  3957   current facts ("this"), admitting arbitrary combinations with "then"
  3958   and derived forms.
  3959 
  3960 * Locales:
  3961   - Goal statements involving the context element "includes" no longer
  3962     generate theorems with internal delta predicates (those ending on
  3963     "_axioms") in the premise.
  3964     Resolve particular premise with <locale>.intro to obtain old form.
  3965   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3966     specification and "includes" elements in goal statement.
  3967   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3968     [intro?] and [elim?] (respectively) by default.
  3969   - Experimental command for instantiation of locales in proof contexts:
  3970         instantiate <label>[<attrs>]: <loc>
  3971     Instantiates locale <loc> and adds all its theorems to the current context
  3972     taking into account their attributes.  Label and attrs are optional
  3973     modifiers, like in theorem declarations.  If present, names of
  3974     instantiated theorems are qualified with <label>, and the attributes
  3975     <attrs> are applied after any attributes these theorems might have already.
  3976       If the locale has assumptions, a chained fact of the form
  3977     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3978     are derived.  The command does not support old-style locales declared
  3979     with "locale (open)".
  3980       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3981 
  3982 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3983   (Isar) contexts.
  3984 
  3985 
  3986 *** HOL ***
  3987 
  3988 * Proof import: new image HOL4 contains the imported library from
  3989   the HOL4 system with about 2500 theorems. It is imported by
  3990   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3991   can be used like any other Isabelle image.  See
  3992   HOL/Import/HOL/README for more information.
  3993 
  3994 * Simplifier:
  3995   - Much improved handling of linear and partial orders.
  3996     Reasoners for linear and partial orders are set up for type classes
  3997     "linorder" and "order" respectively, and are added to the default simpset
  3998     as solvers.  This means that the simplifier can build transitivity chains
  3999     to solve goals from the assumptions.
  4000   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4001     of blast or auto after simplification become unnecessary because the goal
  4002     is solved by simplification already.
  4003 
  4004 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4005     all proved in axiomatic type classes for semirings, rings and fields.
  4006 
  4007 * Numerics:
  4008   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4009     now formalized using the Ring_and_Field theory mentioned above.
  4010   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4011     than before, because now they are set up once in a generic manner.
  4012   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4013     Look for the general versions in Ring_and_Field (and Power if they concern
  4014     exponentiation).
  4015 
  4016 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4017 
  4018 * Records:
  4019   - Record types are now by default printed with their type abbreviation
  4020     instead of the list of all field types. This can be configured via
  4021     the reference "print_record_type_abbr".
  4022   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4023     (not enabled by default).
  4024   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4025     EX x. x = sel r to True (not enabled by default).
  4026   - Tactic "record_split_simp_tac" to split and simplify records added.
  4027 
  4028 * 'specification' command added, allowing for definition by
  4029   specification.  There is also an 'ax_specification' command that
  4030   introduces the new constants axiomatically.
  4031 
  4032 * arith(_tac) is now able to generate counterexamples for reals as well.
  4033 
  4034 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4035 
  4036 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4037   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4038 
  4039 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4040   matrix theory to linear programming.
  4041 
  4042 * Unions and Intersections:
  4043   The latex output syntax of UN and INT has been changed
  4044   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4045   i.e. the index formulae has become a subscript.
  4046   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4047 
  4048 * Unions and Intersections over Intervals:
  4049   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4050   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4051   like in normal math, and corresponding versions for < and for intersection.
  4052 
  4053 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4054   lexicographic dictonary ordering has been added as "lexord".
  4055 
  4056 * ML: the legacy theory structures Int and List have been removed. They had
  4057   conflicted with ML Basis Library structures having the same names.
  4058 
  4059 * 'refute' command added to search for (finite) countermodels.  Only works
  4060   for a fragment of HOL.  The installation of an external SAT solver is
  4061   highly recommended.  See "HOL/Refute.thy" for details.
  4062 
  4063 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4064   formulae under an assignment of free variables to random values.
  4065   In contrast to 'refute', it can deal with inductive datatypes,
  4066   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4067   for examples.
  4068 
  4069 
  4070 *** HOLCF ***
  4071 
  4072 * Streams now come with concatenation and are part of the HOLCF image
  4073 
  4074 
  4075 
  4076 New in Isabelle2003 (May 2003)
  4077 ------------------------------
  4078 
  4079 *** General ***
  4080 
  4081 * Provers/simplifier:
  4082 
  4083   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4084     Assumptions are now subject to complete mutual simplification,
  4085     not just from left to right. The simplifier now preserves
  4086     the order of assumptions.
  4087 
  4088     Potential INCOMPATIBILITY:
  4089 
  4090     -- simp sometimes diverges where the old version did
  4091        not, e.g. invoking simp on the goal
  4092 
  4093         [| P (f x); y = x; f x = f y |] ==> Q
  4094 
  4095        now gives rise to the infinite reduction sequence
  4096 
  4097         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4098 
  4099        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4100        kind of problem.
  4101 
  4102     -- Tactics combining classical reasoner and simplification (such as auto)
  4103        are also affected by this change, because many of them rely on
  4104        simp. They may sometimes diverge as well or yield a different numbers
  4105        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4106        in case of problems. Sometimes subsequent calls to the classical
  4107        reasoner will fail because a preceeding call to the simplifier too
  4108        eagerly simplified the goal, e.g. deleted redundant premises.
  4109 
  4110   - The simplifier trace now shows the names of the applied rewrite rules
  4111 
  4112   - You can limit the number of recursive invocations of the simplifier
  4113     during conditional rewriting (where the simplifie tries to solve the
  4114     conditions before applying the rewrite rule):
  4115     ML "simp_depth_limit := n"
  4116     where n is an integer. Thus you can force termination where previously
  4117     the simplifier would diverge.
  4118 
  4119   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4120 
  4121   - No longer aborts on failed congruence proof.  Instead, the
  4122     congruence is ignored.
  4123 
  4124 * Pure: New generic framework for extracting programs from constructive
  4125   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4126   as HOL/Extraction for some case studies.
  4127 
  4128 * Pure: The main goal of the proof state is no longer shown by default, only
  4129 the subgoals. This behaviour is controlled by a new flag.
  4130    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4131 (ML: Proof.show_main_goal).
  4132 
  4133 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4134 rules whose conclusion matches subgoal 1:
  4135       PG menu: Isabelle/Isar -> Show me -> matching rules
  4136 The rules are ordered by how closely they match the subgoal.
  4137 In particular, rules that solve a subgoal outright are displayed first
  4138 (or rather last, the way they are printed).
  4139 (ML: ProofGeneral.print_intros())
  4140 
  4141 * Pure: New flag trace_unify_fail causes unification to print
  4142 diagnostic information (PG: in trace buffer) when it fails. This is
  4143 useful for figuring out why single step proofs like rule, erule or
  4144 assumption failed.
  4145 
  4146 * Pure: Locale specifications now produce predicate definitions
  4147 according to the body of text (covering assumptions modulo local
  4148 definitions); predicate "loc_axioms" covers newly introduced text,
  4149 while "loc" is cumulative wrt. all included locale expressions; the
  4150 latter view is presented only on export into the global theory
  4151 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4152 on the old view without predicates;
  4153 
  4154 * Pure: predefined locales "var" and "struct" are useful for sharing
  4155 parameters (as in CASL, for example); just specify something like
  4156 ``var x + var y + struct M'' as import;
  4157 
  4158 * Pure: improved thms_containing: proper indexing of facts instead of
  4159 raw theorems; check validity of results wrt. current name space;
  4160 include local facts of proof configuration (also covers active
  4161 locales), cover fixed variables in index; may use "_" in term
  4162 specification; an optional limit for the number of printed facts may
  4163 be given (the default is 40);
  4164 
  4165 * Pure: disallow duplicate fact bindings within new-style theory files
  4166 (batch-mode only);
  4167 
  4168 * Provers: improved induct method: assumptions introduced by case
  4169 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4170 the goal statement); "foo" still refers to all facts collectively;
  4171 
  4172 * Provers: the function blast.overloaded has been removed: all constants
  4173 are regarded as potentially overloaded, which improves robustness in exchange
  4174 for slight decrease in efficiency;
  4175 
  4176 * Provers/linorder: New generic prover for transitivity reasoning over
  4177 linear orders.  Note: this prover is not efficient!
  4178 
  4179 * Isar: preview of problems to finish 'show' now produce an error
  4180 rather than just a warning (in interactive mode);
  4181 
  4182 
  4183 *** HOL ***
  4184 
  4185 * arith(_tac)
  4186 
  4187  - Produces a counter example if it cannot prove a goal.
  4188    Note that the counter example may be spurious if the goal is not a formula
  4189    of quantifier-free linear arithmetic.
  4190    In ProofGeneral the counter example appears in the trace buffer.
  4191 
  4192  - Knows about div k and mod k where k is a numeral of type nat or int.
  4193 
  4194  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4195    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4196    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4197 
  4198 * simp's arithmetic capabilities have been enhanced a bit: it now
  4199 takes ~= in premises into account (by performing a case split);
  4200 
  4201 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4202 are distributed over a sum of terms;
  4203 
  4204 * New tactic "trans_tac" and method "trans" instantiate
  4205 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4206 "<=", "<" and "=").
  4207 
  4208 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4209 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4210 
  4211 * 'typedef' command has new option "open" to suppress the set
  4212 definition;
  4213 
  4214 * functions Min and Max on finite sets have been introduced (theory
  4215 Finite_Set);
  4216 
  4217 * attribute [symmetric] now works for relations as well; it turns
  4218 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4219 
  4220 * induct over a !!-quantified statement (say !!x1..xn):
  4221   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4222 
  4223 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4224 %x. None. Warning: empty_def now refers to the previously hidden definition
  4225 of the empty set.
  4226 
  4227 * Algebra: formalization of classical algebra.  Intended as base for
  4228 any algebraic development in Isabelle.  Currently covers group theory
  4229 (up to Sylow's theorem) and ring theory (Universal Property of
  4230 Univariate Polynomials).  Contributions welcome;
  4231 
  4232 * GroupTheory: deleted, since its material has been moved to Algebra;
  4233 
  4234 * Complex: new directory of the complex numbers with numeric constants,
  4235 nonstandard complex numbers, and some complex analysis, standard and
  4236 nonstandard (Jacques Fleuriot);
  4237 
  4238 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4239 
  4240 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4241 Fleuriot);
  4242 
  4243 * Real/HahnBanach: updated and adapted to locales;
  4244 
  4245 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4246 Gray and Kramer);
  4247 
  4248 * UNITY: added the Meier-Sanders theory of progress sets;
  4249 
  4250 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4251 as abstract algorithms, instantiated to the JVM;
  4252 
  4253 * Bali: Java source language formalization. Type system, operational
  4254 semantics, axiomatic semantics. Supported language features:
  4255 classes, interfaces, objects,virtual methods, static methods,
  4256 static/instance fields, arrays, access modifiers, definite
  4257 assignment, exceptions.
  4258 
  4259 
  4260 *** ZF ***
  4261 
  4262 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4263 universe, etc.);
  4264 
  4265 * Main ZF: virtually all theories converted to new-style format;
  4266 
  4267 
  4268 *** ML ***
  4269 
  4270 * Pure: Tactic.prove provides sane interface for internal proofs;
  4271 omits the infamous "standard" operation, so this is more appropriate
  4272 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4273 
  4274 * Pure: improved error reporting of simprocs;
  4275 
  4276 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4277 up simprocs;
  4278 
  4279 
  4280 *** Document preparation ***
  4281 
  4282 * uses \par instead of \\ for line breaks in theory text. This may
  4283 shift some page breaks in large documents. To get the old behaviour
  4284 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4285 
  4286 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4287 other packages
  4288 
  4289 * \<euro> now needs package babel/greek instead of marvosym (which
  4290 broke \Rightarrow)
  4291 
  4292 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4293 textcomp package)
  4294 
  4295 
  4296 
  4297 New in Isabelle2002 (March 2002)
  4298 --------------------------------
  4299 
  4300 *** Document preparation ***
  4301 
  4302 * greatly simplified document preparation setup, including more
  4303 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4304 instructive isatool mkdir; users should basically be able to get
  4305 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4306 users may run a separate document processing stage manually like this:
  4307 "isatool usedir -D output HOL Test && isatool document Test/output";
  4308 
  4309 * theory dependency graph may now be incorporated into documents;
  4310 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4311 with \includegraphics of LaTeX;
  4312 
  4313 * proper spacing of consecutive markup elements, especially text
  4314 blocks after section headings;
  4315 
  4316 * support bold style (for single symbols only), input syntax is like
  4317 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4318 
  4319 * \<bullet> is now output as bold \cdot by default, which looks much
  4320 better in printed text;
  4321 
  4322 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4323 note that these symbols are currently unavailable in Proof General /
  4324 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4325 
  4326 * isatool latex no longer depends on changed TEXINPUTS, instead
  4327 isatool document copies the Isabelle style files to the target
  4328 location;
  4329 
  4330 
  4331 *** Isar ***
  4332 
  4333 * Pure/Provers: improved proof by cases and induction;
  4334   - 'case' command admits impromptu naming of parameters (such as
  4335     "case (Suc n)");
  4336   - 'induct' method divinates rule instantiation from the inductive
  4337     claim; no longer requires excessive ?P bindings for proper
  4338     instantiation of cases;
  4339   - 'induct' method properly enumerates all possibilities of set/type
  4340     rules; as a consequence facts may be also passed through *type*
  4341     rules without further ado;
  4342   - 'induct' method now derives symbolic cases from the *rulified*
  4343     rule (before it used to rulify cases stemming from the internal
  4344     atomized version); this means that the context of a non-atomic
  4345     statement becomes is included in the hypothesis, avoiding the
  4346     slightly cumbersome show "PROP ?case" form;
  4347   - 'induct' may now use elim-style induction rules without chaining
  4348     facts, using ``missing'' premises from the goal state; this allows
  4349     rules stemming from inductive sets to be applied in unstructured
  4350     scripts, while still benefitting from proper handling of non-atomic
  4351     statements; NB: major inductive premises need to be put first, all
  4352     the rest of the goal is passed through the induction;
  4353   - 'induct' proper support for mutual induction involving non-atomic
  4354     rule statements (uses the new concept of simultaneous goals, see
  4355     below);
  4356   - append all possible rule selections, but only use the first
  4357     success (no backtracking);
  4358   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4359   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4360   - added 'print_induct_rules' (covered by help item in recent Proof
  4361     General versions);
  4362   - moved induct/cases attributes to Pure, methods to Provers;
  4363   - generic method setup instantiated for FOL and HOL;
  4364 
  4365 * Pure: support multiple simultaneous goal statements, for example
  4366 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4367 meta-level mechanism, this acts as if several individual goals had
  4368 been stated separately; in particular common proof methods need to be
  4369 repeated in order to cover all claims; note that a single elimination
  4370 step is *not* sufficient to establish the two conjunctions, so this
  4371 fails:
  4372 
  4373   assume "A & B" then have A and B ..   (*".." fails*)
  4374 
  4375 better use "obtain" in situations as above; alternative refer to
  4376 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4377 
  4378 * Pure: proper integration with ``locales''; unlike the original
  4379 version by Florian Kammller, Isar locales package high-level proof
  4380 contexts rather than raw logical ones (e.g. we admit to include
  4381 attributes everywhere); operations on locales include merge and
  4382 rename; support for implicit arguments (``structures''); simultaneous
  4383 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4384 some examples;
  4385 
  4386 * Pure: the following commands have been ``localized'', supporting a
  4387 target locale specification "(in name)": 'lemma', 'theorem',
  4388 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4389 stored both within the locale and at the theory level (exported and
  4390 qualified by the locale name);
  4391 
  4392 * Pure: theory goals may now be specified in ``long'' form, with
  4393 ad-hoc contexts consisting of arbitrary locale elements. for example
  4394 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4395 definitions may be given, too); the result is a meta-level rule with
  4396 the context elements being discharged in the obvious way;
  4397 
  4398 * Pure: new proof command 'using' allows to augment currently used
  4399 facts after a goal statement ('using' is syntactically analogous to
  4400 'apply', but acts on the goal's facts only); this allows chained facts
  4401 to be separated into parts given before and after a claim, as in
  4402 ``from a and b have C using d and e <proof>'';
  4403 
  4404 * Pure: renamed "antecedent" case to "rule_context";
  4405 
  4406 * Pure: new 'judgment' command records explicit information about the
  4407 object-logic embedding (used by several tools internally); no longer
  4408 use hard-wired "Trueprop";
  4409 
  4410 * Pure: added 'corollary' command;
  4411 
  4412 * Pure: fixed 'token_translation' command;
  4413 
  4414 * Pure: removed obsolete 'exported' attribute;
  4415 
  4416 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4417 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4418 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4419 
  4420 * Pure: method 'atomize' presents local goal premises as object-level
  4421 statements (atomic meta-level propositions); setup controlled via
  4422 rewrite rules declarations of 'atomize' attribute; example
  4423 application: 'induct' method with proper rule statements in improper
  4424 proof *scripts*;
  4425 
  4426 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4427 now consider the syntactic context of assumptions, giving a better
  4428 chance to get type-inference of the arguments right (this is
  4429 especially important for locales);
  4430 
  4431 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4432 mode;
  4433 
  4434 * Pure/obtain: the formal conclusion "thesis", being marked as
  4435 ``internal'', may no longer be reference directly in the text;
  4436 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4437 situations;
  4438 
  4439 * Pure: generic 'sym' attribute which declares a rule both as pure
  4440 'elim?' and for the 'symmetric' operation;
  4441 
  4442 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4443 text; the fixed correlation with particular command syntax has been
  4444 discontinued;
  4445 
  4446 * Pure: new method 'rules' is particularly well-suited for proof
  4447 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4448 but often produces more compact proof terms with less detours;
  4449 
  4450 * Pure/Provers/classical: simplified integration with pure rule
  4451 attributes and methods; the classical "intro?/elim?/dest?"
  4452 declarations coincide with the pure ones; the "rule" method no longer
  4453 includes classically swapped intros; "intro" and "elim" methods no
  4454 longer pick rules from the context; also got rid of ML declarations
  4455 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4456 INCOMPATIBILITY;
  4457 
  4458 * Provers/classical: attribute 'swapped' produces classical inversions
  4459 of introduction rules;
  4460 
  4461 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4462 rules instead of full simplifier context; 'iff' attribute handles
  4463 conditional rules;
  4464 
  4465 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4466 
  4467 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4468 "(permissive)" option to recover old behavior;
  4469 
  4470 * HOL: 'inductive' no longer features separate (collective) attributes
  4471 for 'intros' (was found too confusing);
  4472 
  4473 * HOL: properly declared induction rules less_induct and
  4474 wf_induct_rule;
  4475 
  4476 
  4477 *** HOL ***
  4478 
  4479 * HOL: moved over to sane numeral syntax; the new policy is as
  4480 follows:
  4481 
  4482   - 0 and 1 are polymorphic constants, which are defined on any
  4483   numeric type (nat, int, real etc.);
  4484 
  4485   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4486   binary representation internally;
  4487 
  4488   - type nat has special constructor Suc, and generally prefers Suc 0
  4489   over 1::nat and Suc (Suc 0) over 2::nat;
  4490 
  4491 This change may cause significant problems of INCOMPATIBILITY; here
  4492 are some hints on converting existing sources:
  4493 
  4494   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4495   entities, so expressions involving "-" (unary or binary minus) need
  4496   to be spaced properly;
  4497 
  4498   - existing occurrences of "1" may need to be constraint "1::nat" or
  4499   even replaced by Suc 0; similar for old "2";
  4500 
  4501   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4502 
  4503   - remove all special provisions on numerals in proofs;
  4504 
  4505 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4506 representation (depends on bin_arith_simps in the default context);
  4507 
  4508 * HOL: symbolic syntax for x^2 (numeral 2);
  4509 
  4510 * HOL: the class of all HOL types is now called "type" rather than
  4511 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4512 in axclass/classes, instance/arities, and (usually rare) occurrences
  4513 in typings (of consts etc.); internally the class is called
  4514 "HOL.type", ML programs should refer to HOLogic.typeS;
  4515 
  4516 * HOL/record package improvements:
  4517   - new derived operations "fields" to build a partial record section,
  4518     "extend" to promote a fixed record to a record scheme, and
  4519     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4520     declared as simp by default;
  4521   - shared operations ("more", "fields", etc.) now need to be always
  4522     qualified) --- potential INCOMPATIBILITY;
  4523   - removed "make_scheme" operations (use "make" with "extend") --
  4524     INCOMPATIBILITY;
  4525   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4526   - provides cases/induct rules for use with corresponding Isar
  4527     methods (for concrete records, record schemes, concrete more
  4528     parts, and schematic more parts -- in that order);
  4529   - internal definitions directly based on a light-weight abstract
  4530     theory of product types over typedef rather than datatype;
  4531 
  4532 * HOL: generic code generator for generating executable ML code from
  4533 specifications; specific support for HOL constructs such as inductive
  4534 datatypes and sets, as well as recursive functions; can be invoked
  4535 via 'generate_code' theory section;
  4536 
  4537 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4538 
  4539 * HOL: consolidated and renamed several theories.  In particular:
  4540         Ord.thy has been absorbed into HOL.thy
  4541         String.thy has been absorbed into List.thy
  4542 
  4543 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4544 (beware of argument permutation!);
  4545 
  4546 * HOL: linorder_less_split superseded by linorder_cases;
  4547 
  4548 * HOL/List: "nodups" renamed to "distinct";
  4549 
  4550 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4551 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4552   - Ex_def has changed, now need to use some_eq_ex
  4553 
  4554 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4555 in this (rare) case use:
  4556 
  4557   delSWrapper "split_all_tac"
  4558   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4559 
  4560 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4561 MAY FAIL;
  4562 
  4563 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4564 Isabelle's type classes, ^ on functions and relations has too general
  4565 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4566 necessary to attach explicit type constraints;
  4567 
  4568 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4569 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4570 renamed accordingly (eg "compI" -> "rel_compI").
  4571 
  4572 * HOL: syntax translations now work properly with numerals and records
  4573 expressions;
  4574 
  4575 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4576 of "lam" -- INCOMPATIBILITY;
  4577 
  4578 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4579 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4580 renamed "Product_Type.unit";
  4581 
  4582 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4583 
  4584 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4585 the "cases" method);
  4586 
  4587 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4588 Florian Kammller);
  4589 
  4590 * HOL/IMP: updated and converted to new-style theory format; several
  4591 parts turned into readable document, with proper Isar proof texts and
  4592 some explanations (by Gerwin Klein);
  4593 
  4594 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4595 
  4596 * HOL-Hyperreal is now a logic image;
  4597 
  4598 
  4599 *** HOLCF ***
  4600 
  4601 * Isar: consts/constdefs supports mixfix syntax for continuous
  4602 operations;
  4603 
  4604 * Isar: domain package adapted to new-style theory format, e.g. see
  4605 HOLCF/ex/Dnat.thy;
  4606 
  4607 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4608 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4609 lift.induct_tac, always use UU instead of Undef;
  4610 
  4611 * HOLCF/IMP: updated and converted to new-style theory;
  4612 
  4613 
  4614 *** ZF ***
  4615 
  4616 * Isar: proper integration of logic-specific tools and packages,
  4617 including theory commands '(co)inductive', '(co)datatype',
  4618 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4619 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4620 
  4621 * theory Main no longer includes AC; for the Axiom of Choice, base
  4622 your theory on Main_ZFC;
  4623 
  4624 * the integer library now covers quotients and remainders, with many
  4625 laws relating division to addition, multiplication, etc.;
  4626 
  4627 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4628 typeless version of the formalism;
  4629 
  4630 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4631 format;
  4632 
  4633 * ZF/Induct: new directory for examples of inductive definitions,
  4634 including theory Multiset for multiset orderings; converted to
  4635 new-style theory format;
  4636 
  4637 * ZF: many new theorems about lists, ordinals, etc.;
  4638 
  4639 
  4640 *** General ***
  4641 
  4642 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4643 variable proof controls level of detail: 0 = no proofs (only oracle
  4644 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4645 also ref manual for further ML interfaces;
  4646 
  4647 * Pure/axclass: removed obsolete ML interface
  4648 goal_subclass/goal_arity;
  4649 
  4650 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4651 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4652 separate tokens, so expressions involving minus need to be spaced
  4653 properly;
  4654 
  4655 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4656 rather than "infixl" or "infixr";
  4657 
  4658 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4659 sort constraint specifications in type inference; e.g. "x::_::foo"
  4660 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4661 type variable);
  4662 
  4663 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4664 control output of nested => (types); the default behavior is
  4665 "type_brackets";
  4666 
  4667 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4668 tokens into AST constants;
  4669 
  4670 * Pure/syntax: prefer later declarations of translations and print
  4671 translation functions; potential INCOMPATIBILITY: need to reverse
  4672 multiple declarations for same syntax element constant;
  4673 
  4674 * Pure/show_hyps reset by default (in accordance to existing Isar
  4675 practice);
  4676 
  4677 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4678 addSafter;
  4679 
  4680 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4681 as well;
  4682 
  4683 * system: tested support for MacOS X; should be able to get Isabelle +
  4684 Proof General to work in a plain Terminal after installing Poly/ML
  4685 (e.g. from the Isabelle distribution area) and GNU bash alone
  4686 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4687 support requires further installations, e.g. from
  4688 http://fink.sourceforge.net/);
  4689 
  4690 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4691 
  4692 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4693 of 40 MB), cf. ML_OPTIONS;
  4694 
  4695 * system: Proof General keywords specification is now part of the
  4696 Isabelle distribution (see etc/isar-keywords.el);
  4697 
  4698 * system: support for persistent Proof General sessions (refrain from
  4699 outdating all loaded theories on startup); user may create writable
  4700 logic images like this: ``isabelle -q HOL Test'';
  4701 
  4702 * system: smart selection of Isabelle process versus Isabelle
  4703 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4704 run both "isabelle" and "Isabelle" even if file names are badly
  4705 damaged (executable inspects the case of the first letter of its own
  4706 name); added separate "isabelle-process" and "isabelle-interface";
  4707 
  4708 * system: refrain from any attempt at filtering input streams; no
  4709 longer support ``8bit'' encoding of old isabelle font, instead proper
  4710 iso-latin characters may now be used; the related isatools
  4711 "symbolinput" and "nonascii" have disappeared as well;
  4712 
  4713 * system: removed old "xterm" interface (the print modes "xterm" and
  4714 "xterm_color" are still available for direct use in a suitable
  4715 terminal);
  4716 
  4717 
  4718 
  4719 New in Isabelle99-2 (February 2001)
  4720 -----------------------------------
  4721 
  4722 *** Overview of INCOMPATIBILITIES ***
  4723 
  4724 * HOL: please note that theories in the Library and elsewhere often use the
  4725 new-style (Isar) format; to refer to their theorems in an ML script you must
  4726 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4727 
  4728 * HOL: inductive package no longer splits induction rule aggressively,
  4729 but only as far as specified by the introductions given; the old
  4730 format may be recovered via ML function complete_split_rule or attribute
  4731 'split_rule (complete)';
  4732 
  4733 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4734 gfp_Tarski to gfp_unfold;
  4735 
  4736 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4737 
  4738 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4739 relation); infix "^^" has been renamed "``"; infix "``" has been
  4740 renamed "`"; "univalent" has been renamed "single_valued";
  4741 
  4742 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4743 operation;
  4744 
  4745 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4746 
  4747 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4748 
  4749 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4750 consequence, it is no longer monotonic wrt. the local goal context
  4751 (which is now passed through the inductive cases);
  4752 
  4753 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4754 \<gg> to \<ggreater>;
  4755 
  4756 
  4757 *** Document preparation ***
  4758 
  4759 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4760 available: are "it" for near math-mode best-style output, "sl" for
  4761 slanted text style, and "tt" for plain type-writer; if no
  4762 \isabellestyle command is given, output is according to slanted
  4763 type-writer);
  4764 
  4765 * support sub/super scripts (for single symbols only), input syntax is
  4766 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4767 
  4768 * some more standard symbols; see Appendix A of the system manual for
  4769 the complete list of symbols defined in isabellesym.sty;
  4770 
  4771 * improved isabelle style files; more abstract symbol implementation
  4772 (should now use \isamath{...} and \isatext{...} in custom symbol
  4773 definitions);
  4774 
  4775 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4776 state; Note that presentation of goal states does not conform to
  4777 actual human-readable proof documents.  Please do not include goal
  4778 states into document output unless you really know what you are doing!
  4779 
  4780 * proper indentation of antiquoted output with proportional LaTeX
  4781 fonts;
  4782 
  4783 * no_document ML operator temporarily disables LaTeX document
  4784 generation;
  4785 
  4786 * isatool unsymbolize tunes sources for plain ASCII communication;
  4787 
  4788 
  4789 *** Isar ***
  4790 
  4791 * Pure: Isar now suffers initial goal statements to contain unbound
  4792 schematic variables (this does not conform to actual readable proof
  4793 documents, due to unpredictable outcome and non-compositional proof
  4794 checking); users who know what they are doing may use schematic goals
  4795 for Prolog-style synthesis of proven results;
  4796 
  4797 * Pure: assumption method (an implicit finishing) now handles actual
  4798 rules as well;
  4799 
  4800 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4801 initial goal, declare "that" only as Pure intro (only for single
  4802 steps); the "that" rule assumption may now be involved in implicit
  4803 finishing, thus ".." becomes a feasible for trivial obtains;
  4804 
  4805 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4806 instance proofs may be performed by "..";
  4807 
  4808 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4809 statements as well;
  4810 
  4811 * Pure: more robust selection of calculational rules;
  4812 
  4813 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4814 rule (as well as the assumption rule);
  4815 
  4816 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4817 lemmas, using the graph browser tool;
  4818 
  4819 * Pure: predict failure of "show" in interactive mode;
  4820 
  4821 * Pure: 'thms_containing' now takes actual terms as arguments;
  4822 
  4823 * HOL: improved method 'induct' --- now handles non-atomic goals
  4824 (potential INCOMPATIBILITY); tuned error handling;
  4825 
  4826 * HOL: cases and induct rules now provide explicit hints about the
  4827 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4828 any remaining facts are inserted into the goal verbatim;
  4829 
  4830 * HOL: local contexts (aka cases) may now contain term bindings as
  4831 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4832 the result to be shown in each case;
  4833 
  4834 * HOL: added 'recdef_tc' command;
  4835 
  4836 * isatool convert assists in eliminating legacy ML scripts;
  4837 
  4838 
  4839 *** HOL ***
  4840 
  4841 * HOL/Library: a collection of generic theories to be used together
  4842 with main HOL; the theory loader path already includes this directory
  4843 by default; the following existing theories have been moved here:
  4844 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4845 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4846 
  4847 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4848 modelling and verification task performed in Isabelle/HOL +
  4849 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4850 
  4851 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4852 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4853 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4854 'domain', this makes the theory consistent with mathematical
  4855 literature;
  4856 
  4857 * HOL basics: added overloaded operations "inverse" and "divide"
  4858 (infix "/"), syntax for generic "abs" operation, generic summation
  4859 operator \<Sum>;
  4860 
  4861 * HOL/typedef: simplified package, provide more useful rules (see also
  4862 HOL/subset.thy);
  4863 
  4864 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4865 now expressed as a proper nested rule (old-style tactic scripts may
  4866 require atomize_strip_tac to cope with non-atomic premises);
  4867 
  4868 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4869 to "split_conv" (old name still available for compatibility);
  4870 
  4871 * HOL: improved concrete syntax for strings (e.g. allows translation
  4872 rules with string literals);
  4873 
  4874 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4875  and Fleuriot's mechanization of analysis, including the transcendental
  4876  functions for the reals;
  4877 
  4878 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4879 
  4880 
  4881 *** CTT ***
  4882 
  4883 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4884 "lam" is displayed as TWO lambda-symbols
  4885 
  4886 * CTT: theory Main now available, containing everything (that is, Bool
  4887 and Arith);
  4888 
  4889 
  4890 *** General ***
  4891 
  4892 * Pure: the Simplifier has been implemented properly as a derived rule
  4893 outside of the actual kernel (at last!); the overall performance
  4894 penalty in practical applications is about 50%, while reliability of
  4895 the Isabelle inference kernel has been greatly improved;
  4896 
  4897 * print modes "brackets" and "no_brackets" control output of nested =>
  4898 (types) and ==> (props); the default behaviour is "brackets";
  4899 
  4900 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4901 as assumptions as well;
  4902 
  4903 * system: support Poly/ML 4.0;
  4904 
  4905 * system: isatool install handles KDE version 1 or 2;
  4906 
  4907 
  4908 
  4909 New in Isabelle99-1 (October 2000)
  4910 ----------------------------------
  4911 
  4912 *** Overview of INCOMPATIBILITIES ***
  4913 
  4914 * HOL: simplification of natural numbers is much changed; to partly
  4915 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4916 issue the following ML commands:
  4917 
  4918   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4919   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4920 
  4921 * HOL: simplification no longer dives into case-expressions; this is
  4922 controlled by "t.weak_case_cong" for each datatype t;
  4923 
  4924 * HOL: nat_less_induct renamed to less_induct;
  4925 
  4926 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4927 fixsome to patch .thy and .ML sources automatically;
  4928 
  4929   select_equality  -> some_equality
  4930   select_eq_Ex     -> some_eq_ex
  4931   selectI2EX       -> someI2_ex
  4932   selectI2         -> someI2
  4933   selectI          -> someI
  4934   select1_equality -> some1_equality
  4935   Eps_sym_eq       -> some_sym_eq_trivial
  4936   Eps_eq           -> some_eq_trivial
  4937 
  4938 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4939 
  4940 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4941 instead);
  4942 
  4943 * HOL: the recursion equations generated by 'recdef' are now called
  4944 f.simps instead of f.rules;
  4945 
  4946 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4947 
  4948 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4949 sometimes be needed;
  4950 
  4951 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4952 
  4953 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4954 
  4955 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4956 product is now "<*>" instead of "Times"; the lexicographic product is
  4957 now "<*lex*>" instead of "**";
  4958 
  4959 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4960 of main HOL, but was unused); better use HOL's datatype package;
  4961 
  4962 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4963 the old syntax may be recovered as follows:
  4964 
  4965   syntax (symbols)
  4966     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4967       (infixl "\\<oplus>" 100)
  4968 
  4969 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4970 
  4971 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4972 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4973 internally;
  4974 
  4975 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4976 changed from A/r to A//r;
  4977 
  4978 * ZF: new treatment of arithmetic (nat & int) may break some old
  4979 proofs;
  4980 
  4981 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4982 rulify -> rule_format, elimify -> elim_format, ...);
  4983 
  4984 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4985 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4986 should have to change intro!! to intro? only); replaced "delrule" by
  4987 "rule del";
  4988 
  4989 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4990 
  4991 * Provers: strengthened force_tac by using new first_best_tac;
  4992 
  4993 * LaTeX document preparation: several changes of isabelle.sty (see
  4994 lib/texinputs);
  4995 
  4996 
  4997 *** Document preparation ***
  4998 
  4999 * formal comments (text blocks etc.) in new-style theories may now
  5000 contain antiquotations of thm/prop/term/typ/text to be presented
  5001 according to latex print mode; concrete syntax is like this:
  5002 @{term[show_types] "f(x) = a + x"};
  5003 
  5004 * isatool mkdir provides easy setup of Isabelle session directories,
  5005 including proper document sources;
  5006 
  5007 * generated LaTeX sources are now deleted after successful run
  5008 (isatool document -c); may retain a copy somewhere else via -D option
  5009 of isatool usedir;
  5010 
  5011 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5012 style files, achieving self-contained LaTeX sources and simplifying
  5013 LaTeX debugging;
  5014 
  5015 * old-style theories now produce (crude) LaTeX output as well;
  5016 
  5017 * browser info session directories are now self-contained (may be put
  5018 on WWW server seperately); improved graphs of nested sessions; removed
  5019 graph for 'all sessions';
  5020 
  5021 * several improvements in isabelle style files; \isabellestyle{it}
  5022 produces fake math mode output; \isamarkupheader is now \section by
  5023 default; see lib/texinputs/isabelle.sty etc.;
  5024 
  5025 
  5026 *** Isar ***
  5027 
  5028 * Isar/Pure: local results and corresponding term bindings are now
  5029 subject to Hindley-Milner polymorphism (similar to ML); this
  5030 accommodates incremental type-inference very nicely;
  5031 
  5032 * Isar/Pure: new derived language element 'obtain' supports
  5033 generalized existence reasoning;
  5034 
  5035 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5036 support accumulation of results, without applying any rules yet;
  5037 useful to collect intermediate results without explicit name
  5038 references, and for use with transitivity rules with more than 2
  5039 premises;
  5040 
  5041 * Isar/Pure: scalable support for case-analysis type proofs: new
  5042 'case' language element refers to local contexts symbolically, as
  5043 produced by certain proof methods; internally, case names are attached
  5044 to theorems as "tags";
  5045 
  5046 * Isar/Pure: theory command 'hide' removes declarations from
  5047 class/type/const name spaces;
  5048 
  5049 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5050 indicate potential overloading;
  5051 
  5052 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5053 
  5054 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5055 "{a,b,c}" instead of {a,b,c};
  5056 
  5057 * Isar/Pure now provides its own version of intro/elim/dest
  5058 attributes; useful for building new logics, but beware of confusion
  5059 with the version in Provers/classical;
  5060 
  5061 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5062 case name 'antecedent';
  5063 
  5064 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5065 to the current context is now done automatically);
  5066 
  5067 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5068 for definining proof methods in ML;
  5069 
  5070 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5071 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5072 most cases, one should have to change intro!! to intro? only);
  5073 replaced "delrule" by "rule del";
  5074 
  5075 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5076 'symmetric' attribute (the latter supercedes [RS sym]);
  5077 
  5078 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5079 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5080 well (including splits);
  5081 
  5082 * Isar/Provers: Simplifier and Classical methods now support all kind
  5083 of modifiers used in the past, including 'cong', 'iff', etc.
  5084 
  5085 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5086 of Simplifier and Classical reasoner);
  5087 
  5088 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5089 now support named cases; major packages (inductive, datatype, primrec,
  5090 recdef) support case names and properly name parameters;
  5091 
  5092 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5093 monotonicity conditions are extracted to be proven at end of
  5094 calculations;
  5095 
  5096 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5097 method anyway;
  5098 
  5099 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5100 split_if split_if_asm; datatype package provides theorems foo.splits =
  5101 foo.split foo.split_asm for each datatype;
  5102 
  5103 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5104 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5105 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5106 use "(cases (simplified))" method in proper proof texts);
  5107 
  5108 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5109 
  5110 * Isar: names of theorems etc. may be natural numbers as well;
  5111 
  5112 * Isar: 'pr' command: optional arguments for goals_limit and
  5113 ProofContext.prems_limit; no longer prints theory contexts, but only
  5114 proof states;
  5115 
  5116 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5117 additional print modes to be specified; e.g. "pr(latex)" will print
  5118 proof state according to the Isabelle LaTeX style;
  5119 
  5120 * Isar: improved support for emulating tactic scripts, including proof
  5121 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5122 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5123 (for HOL datatypes);
  5124 
  5125 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5126 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5127 'proof method scripts' have to be in depth-first order;
  5128 
  5129 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5130 
  5131 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5132 should instead use individual commands for printing items
  5133 (print_commands, print_methods etc.);
  5134 
  5135 * Isar: added 'nothing' --- the empty list of theorems;
  5136 
  5137 
  5138 *** HOL ***
  5139 
  5140 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5141 corresponding virtual machine and a specification of its bytecode
  5142 verifier and a lightweight bytecode verifier, including proofs of
  5143 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5144 Cornelia Pusch (see also the homepage of project Bali at
  5145 http://isabelle.in.tum.de/Bali/);
  5146 
  5147 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5148 Clemens Ballarin;
  5149 
  5150 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5151 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5152 Rasmussen;
  5153 
  5154 * HOL/Lattice: fundamental concepts of lattice theory and order
  5155 structures, including duals, properties of bounds versus algebraic
  5156 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5157 Theorem for complete lattices etc.; may also serve as a demonstration
  5158 for abstract algebraic reasoning using axiomatic type classes, and
  5159 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5160 
  5161 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5162 von Oheimb;
  5163 
  5164 * HOL/IMPP: extension of IMP with local variables and mutually
  5165 recursive procedures, by David von Oheimb;
  5166 
  5167 * HOL/Lambda: converted into new-style theory and document;
  5168 
  5169 * HOL/ex/Multiquote: example of multiple nested quotations and
  5170 anti-quotations -- basically a generalized version of de-Bruijn
  5171 representation; very useful in avoiding lifting of operations;
  5172 
  5173 * HOL/record: added general record equality rule to simpset; fixed
  5174 select-update simplification procedure to handle extended records as
  5175 well; admit "r" as field name;
  5176 
  5177 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5178 other numeric types and also as the identity of groups, rings, etc.;
  5179 
  5180 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5181 Types nat and int belong to this axclass;
  5182 
  5183 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5184    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5185    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5186   two terms #m*u and #n*u are replaced by #(m+n)*u
  5187     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5188   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5189     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5190 
  5191 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5192 powerful prover for predicate logic but knows nothing of clasets; see
  5193 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5194 
  5195 * HOL: new version of "case_tac" subsumes both boolean case split and
  5196 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5197 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5198 
  5199 * HOL: simplification no longer dives into case-expressions: only the
  5200 selector expression is simplified, but not the remaining arms; to
  5201 enable full simplification of case-expressions for datatype t, you may
  5202 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5203 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5204 
  5205 * HOL/recdef: the recursion equations generated by 'recdef' for
  5206 function 'f' are now called f.simps instead of f.rules; if all
  5207 termination conditions are proved automatically, these simplification
  5208 rules are added to the simpset, as in primrec; rules may be named
  5209 individually as well, resulting in a separate list of theorems for
  5210 each equation;
  5211 
  5212 * HOL/While is a new theory that provides a while-combinator. It
  5213 permits the definition of tail-recursive functions without the
  5214 provision of a termination measure. The latter is necessary once the
  5215 invariant proof rule for while is applied.
  5216 
  5217 * HOL: new (overloaded) notation for the set of elements below/above
  5218 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5219 
  5220 * HOL: theorems impI, allI, ballI bound as "strip";
  5221 
  5222 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5223 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5224 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5225 
  5226 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5227 
  5228 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5229 main HOL, but was unused);
  5230 
  5231 * HOL: fewer consts declared as global (e.g. have to refer to
  5232 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5233 
  5234 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5235 in case of overlap with user translations (e.g. judgements over
  5236 tuples); (note that the underlying logical represenation is still
  5237 bogus);
  5238 
  5239 
  5240 *** ZF ***
  5241 
  5242 * ZF: simplification automatically cancels common terms in arithmetic
  5243 expressions over nat and int;
  5244 
  5245 * ZF: new treatment of nat to minimize type-checking: all operators
  5246 coerce their operands to a natural number using the function natify,
  5247 making the algebraic laws unconditional;
  5248 
  5249 * ZF: as above, for int: operators coerce their operands to an integer
  5250 using the function intify;
  5251 
  5252 * ZF: the integer library now contains many of the usual laws for the
  5253 orderings, including $<=, and monotonicity laws for $+ and $*;
  5254 
  5255 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5256 simplification;
  5257 
  5258 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5259 to the simplifier and classical reasoner simultaneously;
  5260 
  5261 
  5262 *** General ***
  5263 
  5264 * Provers: blast_tac now handles actual object-logic rules as
  5265 assumptions; note that auto_tac uses blast_tac internally as well;
  5266 
  5267 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5268 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5269 
  5270 * Provers: delrules now handles destruct rules as well (no longer need
  5271 explicit make_elim);
  5272 
  5273 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5274   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5275 use instead the strong form,
  5276   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5277 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5278 from destruct-rules;
  5279 
  5280 * Provers: Simplifier.easy_setup provides a fast path to basic
  5281 Simplifier setup for new object-logics;
  5282 
  5283 * Pure: AST translation rules no longer require constant head on LHS;
  5284 
  5285 * Pure: improved name spaces: ambiguous output is qualified; support
  5286 for hiding of names;
  5287 
  5288 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5289 XSYMBOL_HOME; no longer need to do manual configuration in most
  5290 situations;
  5291 
  5292 * system: compression of ML heaps images may now be controlled via -c
  5293 option of isabelle and isatool usedir (currently only observed by
  5294 Poly/ML);
  5295 
  5296 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5297 useful for remote X11);
  5298 
  5299 * system: provide TAGS file for Isabelle sources;
  5300 
  5301 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5302 order;
  5303 
  5304 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5305 timing flag supersedes proof_timing and Toplevel.trace;
  5306 
  5307 * ML: new combinators |>> and |>>> for incremental transformations
  5308 with secondary results (e.g. certain theory extensions):
  5309 
  5310 * ML: PureThy.add_defs gets additional argument to indicate potential
  5311 overloading (usually false);
  5312 
  5313 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5314 results;
  5315 
  5316 
  5317 
  5318 New in Isabelle99 (October 1999)
  5319 --------------------------------
  5320 
  5321 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5322 
  5323 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5324 are no longer simplified.  (This allows the simplifier to unfold recursive
  5325 functional programs.)  To restore the old behaviour, declare
  5326 
  5327     Delcongs [if_weak_cong];
  5328 
  5329 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5330 complement;
  5331 
  5332 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5333 
  5334 * HOL/datatype: mutual_induct_tac no longer exists --
  5335   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5336 
  5337 * HOL/typedef: fixed type inference for representing set; type
  5338 arguments now have to occur explicitly on the rhs as type constraints;
  5339 
  5340 * ZF: The con_defs part of an inductive definition may no longer refer
  5341 to constants declared in the same theory;
  5342 
  5343 * HOL, ZF: the function mk_cases, generated by the inductive
  5344 definition package, has lost an argument.  To simplify its result, it
  5345 uses the default simpset instead of a supplied list of theorems.
  5346 
  5347 * HOL/List: the constructors of type list are now Nil and Cons;
  5348 
  5349 * Simplifier: the type of the infix ML functions
  5350         setSSolver addSSolver setSolver addSolver
  5351 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5352 for packaging solvers. A solver is created via
  5353         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5354 where the string argument is only a comment.
  5355 
  5356 
  5357 *** Proof tools ***
  5358 
  5359 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5360 decision procedure for linear arithmetic. Currently it is used for
  5361 types `nat', `int', and `real' in HOL (see below); it can, should and
  5362 will be instantiated for other types and logics as well.
  5363 
  5364 * The simplifier now accepts rewrite rules with flexible heads, eg
  5365      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5366   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5367   matching.
  5368 
  5369 
  5370 *** General ***
  5371 
  5372 * New Isabelle/Isar subsystem provides an alternative to traditional
  5373 tactical theorem proving; together with the ProofGeneral/isar user
  5374 interface it offers an interactive environment for developing human
  5375 readable proof documents (Isar == Intelligible semi-automated
  5376 reasoning); for further information see isatool doc isar-ref,
  5377 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5378 
  5379 * improved and simplified presentation of theories: better HTML markup
  5380 (including colors), graph views in several sizes; isatool usedir now
  5381 provides a proper interface for user theories (via -P option); actual
  5382 document preparation based on (PDF)LaTeX is available as well (for
  5383 new-style theories only); see isatool doc system for more information;
  5384 
  5385 * native support for Proof General, both for classic Isabelle and
  5386 Isabelle/Isar;
  5387 
  5388 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5389 using the graph browser tool;
  5390 
  5391 * Isabelle manuals now also available as PDF;
  5392 
  5393 * theory loader rewritten from scratch (may not be fully
  5394 bug-compatible); old loadpath variable has been replaced by show_path,
  5395 add_path, del_path, reset_path functions; new operations such as
  5396 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5397 isatool doc ref);
  5398 
  5399 * improved isatool install: option -k creates KDE application icon,
  5400 option -p DIR installs standalone binaries;
  5401 
  5402 * added ML_PLATFORM setting (useful for cross-platform installations);
  5403 more robust handling of platform specific ML images for SML/NJ;
  5404 
  5405 * the settings environment is now statically scoped, i.e. it is never
  5406 created again in sub-processes invoked from isabelle, isatool, or
  5407 Isabelle;
  5408 
  5409 * path element specification '~~' refers to '$ISABELLE_HOME';
  5410 
  5411 * in locales, the "assumes" and "defines" parts may be omitted if
  5412 empty;
  5413 
  5414 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5415 long arrows);
  5416 
  5417 * new print_mode "HTML";
  5418 
  5419 * new flag show_tags controls display of tags of theorems (which are
  5420 basically just comments that may be attached by some tools);
  5421 
  5422 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5423 mode and goal output format:
  5424 
  5425 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5426 244c244
  5427 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5428 ---
  5429 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5430 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5431 181c181
  5432 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5433 ---
  5434 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5435 
  5436 * function bind_thms stores lists of theorems (cf. bind_thm);
  5437 
  5438 * new shorthand tactics ftac, eatac, datac, fatac;
  5439 
  5440 * qed (and friends) now accept "" as result name; in that case the
  5441 theorem is not stored, but proper checks and presentation of the
  5442 result still apply;
  5443 
  5444 * theorem database now also indexes constants "Trueprop", "all",
  5445 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5446 
  5447 
  5448 *** HOL ***
  5449 
  5450 ** HOL arithmetic **
  5451 
  5452 * There are now decision procedures for linear arithmetic over nat and
  5453 int:
  5454 
  5455 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5456 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5457 are treated as atomic; subformulae not involving type `nat' or `int'
  5458 are ignored; quantified subformulae are ignored unless they are
  5459 positive universal or negative existential. The tactic has to be
  5460 invoked by hand and can be a little bit slow. In particular, the
  5461 running time is exponential in the number of occurrences of `min' and
  5462 `max', and `-' on `nat'.
  5463 
  5464 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5465 (negated) (in)equalities among the premises and the conclusion into
  5466 account (i.e. no compound formulae) and does not know about `min' and
  5467 `max', and `-' on `nat'. It is fast and is used automatically by the
  5468 simplifier.
  5469 
  5470 NB: At the moment, these decision procedures do not cope with mixed
  5471 nat/int formulae where the two parts interact, such as `m < n ==>
  5472 int(m) < int(n)'.
  5473 
  5474 * HOL/Numeral provides a generic theory of numerals (encoded
  5475 efficiently as bit strings); setup for types nat/int/real is in place;
  5476 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5477 int, existing theories and proof scripts may require a few additional
  5478 type constraints;
  5479 
  5480 * integer division and remainder can now be performed on constant
  5481 arguments;
  5482 
  5483 * many properties of integer multiplication, division and remainder
  5484 are now available;
  5485 
  5486 * An interface to the Stanford Validity Checker (SVC) is available through the
  5487 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5488 are proved automatically.  SVC must be installed separately, and its results
  5489 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5490 invocation of the underlying oracle).  For SVC see
  5491   http://verify.stanford.edu/SVC
  5492 
  5493 * IsaMakefile: the HOL-Real target now builds an actual image;
  5494 
  5495 
  5496 ** HOL misc **
  5497 
  5498 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5499 (in Isabelle/Isar) -- by Gertrud Bauer;
  5500 
  5501 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5502 analysis for assembly languages with subtypes;
  5503 
  5504 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5505 -- avoids syntactic ambiguities and treats state, transition, and
  5506 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5507 changed syntax and (many) tactics;
  5508 
  5509 * HOL/inductive: Now also handles more general introduction rules such
  5510   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5511   theorems are now maintained within the theory (maintained via the
  5512   "mono" attribute);
  5513 
  5514 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5515   (using function types) such as
  5516 
  5517   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5518 
  5519 * HOL/record: record_simproc (part of the default simpset) takes care
  5520 of selectors applied to updated records; record_split_tac is no longer
  5521 part of the default claset; update_defs may now be removed from the
  5522 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5523 
  5524   claset_ref () := claset() addSWrapper record_split_wrapper;
  5525   Delsimprocs [record_simproc]
  5526 
  5527 * HOL/typedef: fixed type inference for representing set; type
  5528 arguments now have to occur explicitly on the rhs as type constraints;
  5529 
  5530 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5531 names rather than an ML expression;
  5532 
  5533 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5534 supplied later.  Program schemes can be defined, such as
  5535     "While B C s = (if B s then While B C (C s) else s)"
  5536 where the well-founded relation can be chosen after B and C have been given.
  5537 
  5538 * HOL/List: the constructors of type list are now Nil and Cons;
  5539 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5540 course, ML tools referring to List.list.op # etc. have to be adapted;
  5541 
  5542 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5543 disabled by default; run isabelle with option -m HOL to get back to
  5544 the original Gordon/HOL-style output;
  5545 
  5546 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5547 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5548 
  5549 * HOL basic syntax simplified (more orthogonal): all variants of
  5550 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5551 Eps operator is provided as well: "SOME x. P[x]";
  5552 
  5553 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5554 
  5555 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5556 thus available for user theories;
  5557 
  5558 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5559 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5560 time;
  5561 
  5562 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5563 several times and then mp;
  5564 
  5565 
  5566 *** LK ***
  5567 
  5568 * the notation <<...>> is now available as a notation for sequences of
  5569 formulas;
  5570 
  5571 * the simplifier is now installed
  5572 
  5573 * the axiom system has been generalized (thanks to Soren Heilmann)
  5574 
  5575 * the classical reasoner now has a default rule database
  5576 
  5577 
  5578 *** ZF ***
  5579 
  5580 * new primrec section allows primitive recursive functions to be given
  5581 directly (as in HOL) over datatypes and the natural numbers;
  5582 
  5583 * new tactics induct_tac and exhaust_tac for induction (or case
  5584 analysis) over datatypes and the natural numbers;
  5585 
  5586 * the datatype declaration of type T now defines the recursor T_rec;
  5587 
  5588 * simplification automatically does freeness reasoning for datatype
  5589 constructors;
  5590 
  5591 * automatic type-inference, with AddTCs command to insert new
  5592 type-checking rules;
  5593 
  5594 * datatype introduction rules are now added as Safe Introduction rules
  5595 to the claset;
  5596 
  5597 * the syntax "if P then x else y" is now available in addition to
  5598 if(P,x,y);
  5599 
  5600 
  5601 *** Internal programming interfaces ***
  5602 
  5603 * tuned simplifier trace output; new flag debug_simp;
  5604 
  5605 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5606 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5607 
  5608 * AxClass.axclass_tac lost the theory argument;
  5609 
  5610 * tuned current_goals_markers semantics: begin / end goal avoids
  5611 printing empty lines;
  5612 
  5613 * removed prs and prs_fn hook, which was broken because it did not
  5614 include \n in its semantics, forcing writeln to add one
  5615 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5616 string -> unit if you really want to output text without newline;
  5617 
  5618 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5619 plain output, interface builders may have to enable 'isabelle_font'
  5620 mode to get Isabelle font glyphs as before;
  5621 
  5622 * refined token_translation interface; INCOMPATIBILITY: output length
  5623 now of type real instead of int;
  5624 
  5625 * theory loader actions may be traced via new ThyInfo.add_hook
  5626 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5627 your own database of information attached to *whole* theories -- as
  5628 opposed to intra-theory data slots offered via TheoryDataFun;
  5629 
  5630 * proper handling of dangling sort hypotheses (at last!);
  5631 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5632 extra sort hypotheses that can be witnessed from the type signature;
  5633 the force_strip_shyps flag is gone, any remaining shyps are simply
  5634 left in the theorem (with a warning issued by strip_shyps_warning);
  5635 
  5636 
  5637 
  5638 New in Isabelle98-1 (October 1998)
  5639 ----------------------------------
  5640 
  5641 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5642 
  5643 * several changes of automated proof tools;
  5644 
  5645 * HOL: major changes to the inductive and datatype packages, including
  5646 some minor incompatibilities of theory syntax;
  5647 
  5648 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5649 called `inj_on';
  5650 
  5651 * HOL: removed duplicate thms in Arith:
  5652   less_imp_add_less  should be replaced by  trans_less_add1
  5653   le_imp_add_le      should be replaced by  trans_le_add1
  5654 
  5655 * HOL: unary minus is now overloaded (new type constraints may be
  5656 required);
  5657 
  5658 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5659 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5660 now taken as an integer constant.
  5661 
  5662 * Pure: ML function 'theory_of' renamed to 'theory';
  5663 
  5664 
  5665 *** Proof tools ***
  5666 
  5667 * Simplifier:
  5668   1. Asm_full_simp_tac is now more aggressive.
  5669      1. It will sometimes reorient premises if that increases their power to
  5670         simplify.
  5671      2. It does no longer proceed strictly from left to right but may also
  5672         rotate premises to achieve further simplification.
  5673      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5674      old Asm_full_simp_tac in that it does not rotate premises.
  5675   2. The simplifier now knows a little bit about nat-arithmetic.
  5676 
  5677 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5678 allows for selected deletion of wrappers, by introduction of names for
  5679 wrapper functionals.  This implies that addbefore, addSbefore,
  5680 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5681 and that adding two tactics with the same name overwrites the first
  5682 one (emitting a warning).
  5683   type wrapper = (int -> tactic) -> (int -> tactic)
  5684   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5685   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5686   delWrapper, delSWrapper: claset *  string            -> claset
  5687   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5688 
  5689 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5690 semantics; addbefore now affects only the unsafe part of step_tac
  5691 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5692 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5693 by Force_tac;
  5694 
  5695 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5696 compWrapper; added safe wrapper (and access functions for it);
  5697 
  5698 * HOL/split_all_tac is now much faster and fails if there is nothing
  5699 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5700 and the names of the automatically generated variables have changed.
  5701 split_all_tac has moved within claset() from unsafe wrappers to safe
  5702 wrappers, which means that !!-bound variables are split much more
  5703 aggressively, and safe_tac and clarify_tac now split such variables.
  5704 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5705 Note: the same holds for record_split_tac, which does the job of
  5706 split_all_tac for record fields.
  5707 
  5708 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5709 permanently to the default simpset using Addsplits just like
  5710 Addsimps. They can be removed via Delsplits just like
  5711 Delsimps. Lower-case versions are also available.
  5712 
  5713 * HOL/Simplifier: The rule split_if is now part of the default
  5714 simpset. This means that the simplifier will eliminate all occurrences
  5715 of if-then-else in the conclusion of a goal. To prevent this, you can
  5716 either remove split_if completely from the default simpset by
  5717 `Delsplits [split_if]' or remove it in a specific call of the
  5718 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5719 other case splitting rules to/from the default simpset: every datatype
  5720 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5721 t is the name of the datatype).
  5722 
  5723 * Classical reasoner / Simplifier combination: new force_tac (and
  5724 derivatives Force_tac, force) combines rewriting and classical
  5725 reasoning (and whatever other tools) similarly to auto_tac, but is
  5726 aimed to solve the given subgoal completely.
  5727 
  5728 
  5729 *** General ***
  5730 
  5731 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5732 and `goalw': the theory is no longer needed as an explicit argument -
  5733 the current theory context is used; assumptions are no longer returned
  5734 at the ML-level unless one of them starts with ==> or !!; it is
  5735 recommended to convert to these new commands using isatool fixgoal
  5736 (backup your sources first!);
  5737 
  5738 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5739 the current theory context, and 'theory' to lookup stored theories;
  5740 
  5741 * new theory section 'locale' for declaring constants, assumptions and
  5742 definitions that have local scope;
  5743 
  5744 * new theory section 'nonterminals' for purely syntactic types;
  5745 
  5746 * new theory section 'setup' for generic ML setup functions
  5747 (e.g. package initialization);
  5748 
  5749 * the distribution now includes Isabelle icons: see
  5750 lib/logo/isabelle-{small,tiny}.xpm;
  5751 
  5752 * isatool install - install binaries with absolute references to
  5753 ISABELLE_HOME/bin;
  5754 
  5755 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5756 
  5757 * print mode 'emacs' reserved for Isamode;
  5758 
  5759 * support multiple print (ast) translations per constant name;
  5760 
  5761 * theorems involving oracles are now printed with a suffixed [!];
  5762 
  5763 
  5764 *** HOL ***
  5765 
  5766 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5767 
  5768 * HOL/inductive package reorganized and improved: now supports mutual
  5769 definitions such as
  5770 
  5771   inductive EVEN ODD
  5772     intrs
  5773       null "0 : EVEN"
  5774       oddI "n : EVEN ==> Suc n : ODD"
  5775       evenI "n : ODD ==> Suc n : EVEN"
  5776 
  5777 new theorem list "elims" contains an elimination rule for each of the
  5778 recursive sets; inductive definitions now handle disjunctive premises
  5779 correctly (also ZF);
  5780 
  5781 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5782 "mutual_induct" no longer exists - the induction rule is always
  5783 contained in "induct";
  5784 
  5785 
  5786 * HOL/datatype package re-implemented and greatly improved: now
  5787 supports mutually recursive datatypes such as
  5788 
  5789   datatype
  5790     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5791             | SUM ('a aexp) ('a aexp)
  5792             | DIFF ('a aexp) ('a aexp)
  5793             | NUM 'a
  5794   and
  5795     'a bexp = LESS ('a aexp) ('a aexp)
  5796             | AND ('a bexp) ('a bexp)
  5797             | OR ('a bexp) ('a bexp)
  5798 
  5799 as well as indirectly recursive datatypes such as
  5800 
  5801   datatype
  5802     ('a, 'b) term = Var 'a
  5803                   | App 'b ((('a, 'b) term) list)
  5804 
  5805 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5806 induction on mutually / indirectly recursive datatypes.
  5807 
  5808 Primrec equations are now stored in theory and can be accessed via
  5809 <function_name>.simps.
  5810 
  5811 INCOMPATIBILITIES:
  5812 
  5813   - Theories using datatypes must now have theory Datatype as an
  5814     ancestor.
  5815   - The specific <typename>.induct_tac no longer exists - use the
  5816     generic induct_tac instead.
  5817   - natE has been renamed to nat.exhaust - use exhaust_tac
  5818     instead of res_inst_tac ... natE. Note that the variable
  5819     names in nat.exhaust differ from the names in natE, this
  5820     may cause some "fragile" proofs to fail.
  5821   - The theorems split_<typename>_case and split_<typename>_case_asm
  5822     have been renamed to <typename>.split and <typename>.split_asm.
  5823   - Since default sorts of type variables are now handled correctly,
  5824     some datatype definitions may have to be annotated with explicit
  5825     sort constraints.
  5826   - Primrec definitions no longer require function name and type
  5827     of recursive argument.
  5828 
  5829 Consider using isatool fixdatatype to adapt your theories and proof
  5830 scripts to the new package (backup your sources first!).
  5831 
  5832 
  5833 * HOL/record package: considerably improved implementation; now
  5834 includes concrete syntax for record types, terms, updates; theorems
  5835 for surjective pairing and splitting !!-bound record variables; proof
  5836 support is as follows:
  5837 
  5838   1) standard conversions (selectors or updates applied to record
  5839 constructor terms) are part of the standard simpset;
  5840 
  5841   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5842 made part of standard simpset and claset via addIffs;
  5843 
  5844   3) a tactic for record field splitting (record_split_tac) is part of
  5845 the standard claset (addSWrapper);
  5846 
  5847 To get a better idea about these rules you may retrieve them via
  5848 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5849 the name of your record type.
  5850 
  5851 The split tactic 3) conceptually simplifies by the following rule:
  5852 
  5853   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5854 
  5855 Thus any record variable that is bound by meta-all will automatically
  5856 blow up into some record constructor term, consequently the
  5857 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5858 solve record problems automatically.
  5859 
  5860 
  5861 * reorganized the main HOL image: HOL/Integ and String loaded by
  5862 default; theory Main includes everything;
  5863 
  5864 * automatic simplification of integer sums and comparisons, using cancellation;
  5865 
  5866 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5867 
  5868 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5869 
  5870 * many new identities for unions, intersections, set difference, etc.;
  5871 
  5872 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5873 called split_if, split_split, split_sum_case and split_nat_case (to go
  5874 with add/delsplits);
  5875 
  5876 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5877 (?x::unit) = (); this is made part of the default simpset, which COULD
  5878 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5879 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5880 unit_abs_eta_conv is added in order to counter the effect of
  5881 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5882 %u.f();
  5883 
  5884 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5885 makes more sense);
  5886 
  5887 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5888   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5889   disjointness reasoning but breaking a few old proofs.
  5890 
  5891 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5892 to 'converse' from 'inverse' (for compatibility with ZF and some
  5893 literature);
  5894 
  5895 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5896 the well-founded relation;
  5897 
  5898 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5899     Compl A.  The "Compl" syntax remains available as input syntax for this
  5900     release ONLY.
  5901 
  5902 * HOL/Update: new theory of function updates:
  5903     f(a:=b) == %x. if x=a then b else f x
  5904 may also be iterated as in f(a:=b,c:=d,...);
  5905 
  5906 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5907 
  5908 * HOL/List:
  5909   - new function list_update written xs[i:=v] that updates the i-th
  5910     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5911   - new function `upt' written [i..j(] which generates the list
  5912     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5913     bound write [i..j], which is a shorthand for [i..j+1(].
  5914   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5915 
  5916 * HOL/Arith:
  5917   - removed 'pred' (predecessor) function;
  5918   - generalized some theorems about n-1;
  5919   - many new laws about "div" and "mod";
  5920   - new laws about greatest common divisors (see theory ex/Primes);
  5921 
  5922 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5923 instead of "inverse";
  5924 
  5925 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5926   of the multiset ordering;
  5927 
  5928 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5929   (not included by default);
  5930 
  5931 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5932 
  5933 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5934   programs, i.e. different program variables may have different types.
  5935 
  5936 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5937   [previously, this check worked only if the rewrite rule was unconditional]
  5938   Now rew can involve either definitions or equalities (either == or =).
  5939 
  5940 
  5941 *** ZF ***
  5942 
  5943 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5944   only the theorems proved on ZF.ML;
  5945 
  5946 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5947   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5948   disjointness reasoning but breaking a few old proofs.
  5949 
  5950 * ZF/Update: new theory of function updates
  5951     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5952   may also be iterated as in f(a:=b,c:=d,...);
  5953 
  5954 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5955 
  5956 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5957   [previously, this check worked only if the rewrite rule was unconditional]
  5958   Now rew can involve either definitions or equalities (either == or =).
  5959 
  5960 * case_tac provided for compatibility with HOL
  5961     (like the old excluded_middle_tac, but with subgoals swapped)
  5962 
  5963 
  5964 *** Internal programming interfaces ***
  5965 
  5966 * Pure: several new basic modules made available for general use, see
  5967 also src/Pure/README;
  5968 
  5969 * improved the theory data mechanism to support encapsulation (data
  5970 kind name replaced by private Object.kind, acting as authorization
  5971 key); new type-safe user interface via functor TheoryDataFun; generic
  5972 print_data function becomes basically useless;
  5973 
  5974 * removed global_names compatibility flag -- all theory declarations
  5975 are qualified by default;
  5976 
  5977 * module Pure/Syntax now offers quote / antiquote translation
  5978 functions (useful for Hoare logic etc. with implicit dependencies);
  5979 see HOL/ex/Antiquote for an example use;
  5980 
  5981 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5982 cterm -> thm;
  5983 
  5984 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5985 subgoal;
  5986 
  5987 * Display.print_goals function moved to Locale.print_goals;
  5988 
  5989 * standard print function for goals supports current_goals_markers
  5990 variable for marking begin of proof, end of proof, start of goal; the
  5991 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5992 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5993 for example;
  5994 
  5995 
  5996 
  5997 New in Isabelle98 (January 1998)
  5998 --------------------------------
  5999 
  6000 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6001 
  6002 * changed lexical syntax of terms / types: dots made part of long
  6003 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6004 
  6005 * simpset (and claset) reference variable replaced by functions
  6006 simpset / simpset_ref;
  6007 
  6008 * no longer supports theory aliases (via merge) and non-trivial
  6009 implicit merge of thms' signatures;
  6010 
  6011 * most internal names of constants changed due to qualified names;
  6012 
  6013 * changed Pure/Sequence interface (see Pure/seq.ML);
  6014 
  6015 
  6016 *** General Changes ***
  6017 
  6018 * hierachically structured name spaces (for consts, types, axms, thms
  6019 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6020 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6021 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6022 long_names for fully qualified output names; NOTE: ML programs
  6023 (special tactics, packages etc.) referring to internal names may have
  6024 to be adapted to cope with fully qualified names; in case of severe
  6025 backward campatibility problems try setting 'global_names' at compile
  6026 time to have enrything declared within a flat name space; one may also
  6027 fine tune name declarations in theories via the 'global' and 'local'
  6028 section;
  6029 
  6030 * reimplemented the implicit simpset and claset using the new anytype
  6031 data filed in signatures; references simpset:simpset ref etc. are
  6032 replaced by functions simpset:unit->simpset and
  6033 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6034 to patch your ML files accordingly;
  6035 
  6036 * HTML output now includes theory graph data for display with Java
  6037 applet or isatool browser; data generated automatically via isatool
  6038 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6039 
  6040 * defs may now be conditional; improved rewrite_goals_tac to handle
  6041 conditional equations;
  6042 
  6043 * defs now admits additional type arguments, using TYPE('a) syntax;
  6044 
  6045 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6046 creates a new theory node; implicit merge of thms' signatures is
  6047 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6048 transfer:theory->thm->thm in (rare) cases;
  6049 
  6050 * improved handling of draft signatures / theories; draft thms (and
  6051 ctyps, cterms) are automatically promoted to real ones;
  6052 
  6053 * slightly changed interfaces for oracles: admit many per theory, named
  6054 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6055 
  6056 * print_goals: optional output of const types (set show_consts and
  6057 show_types);
  6058 
  6059 * improved output of warnings (###) and errors (***);
  6060 
  6061 * subgoal_tac displays a warning if the new subgoal has type variables;
  6062 
  6063 * removed old README and Makefiles;
  6064 
  6065 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6066 
  6067 * removed obsolete init_pps and init_database;
  6068 
  6069 * deleted the obsolete tactical STATE, which was declared by
  6070     fun STATE tacfun st = tacfun st st;
  6071 
  6072 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6073 (which abbreviates $HOME);
  6074 
  6075 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6076 use isatool fixseq to adapt your ML programs (this works for fully
  6077 qualified references to the Sequence structure only!);
  6078 
  6079 * use_thy no longer requires writable current directory; it always
  6080 reloads .ML *and* .thy file, if either one is out of date;
  6081 
  6082 
  6083 *** Classical Reasoner ***
  6084 
  6085 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6086 tactics that use classical reasoning to simplify a subgoal without
  6087 splitting it into several subgoals;
  6088 
  6089 * Safe_tac: like safe_tac but uses the default claset;
  6090 
  6091 
  6092 *** Simplifier ***
  6093 
  6094 * added simplification meta rules:
  6095     (asm_)(full_)simplify: simpset -> thm -> thm;
  6096 
  6097 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6098 logics (again);
  6099 
  6100 * added prems argument to simplification procedures;
  6101 
  6102 * HOL, FOL, ZF: added infix function `addsplits':
  6103   instead of `<simpset> setloop (split_tac <thms>)'
  6104   you can simply write `<simpset> addsplits <thms>'
  6105 
  6106 
  6107 *** Syntax ***
  6108 
  6109 * TYPE('a) syntax for type reflection terms;
  6110 
  6111 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6112 
  6113 * pretty printer: changed order of mixfix annotation preference (again!);
  6114 
  6115 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6116 
  6117 
  6118 *** HOL ***
  6119 
  6120 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6121   with `addloop' of the simplifier to faciliate case splitting in premises.
  6122 
  6123 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6124 
  6125 * HOL/Auth: new protocol proofs including some for the Internet
  6126   protocol TLS;
  6127 
  6128 * HOL/Map: new theory of `maps' a la VDM;
  6129 
  6130 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6131 cancelling out common nat summands from =, <, <= (in)equalities, or
  6132 differences; simplification procedures nat_cancel_factor for
  6133 cancelling common factor from =, <, <= (in)equalities over natural
  6134 sums; nat_cancel contains both kinds of procedures, it is installed by
  6135 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6136 
  6137 * HOL/simplifier: terms of the form
  6138   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6139   are rewritten to
  6140   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6141   and those of the form
  6142   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6143   are rewritten to
  6144   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6145 
  6146 * HOL/datatype
  6147   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6148 
  6149   P(t_case f1 ... fn x) =
  6150      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6151         ...
  6152        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6153      )
  6154 
  6155   and a theorem `split_t_case_asm' of the form
  6156 
  6157   P(t_case f1 ... fn x) =
  6158     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6159         ...
  6160        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6161      )
  6162   which can be added to a simpset via `addsplits'. The existing theorems
  6163   expand_list_case and expand_option_case have been renamed to
  6164   split_list_case and split_option_case.
  6165 
  6166 * HOL/Arithmetic:
  6167   - `pred n' is automatically converted to `n-1'.
  6168     Users are strongly encouraged not to use `pred' any longer,
  6169     because it will disappear altogether at some point.
  6170   - Users are strongly encouraged to write "0 < n" rather than
  6171     "n ~= 0". Theorems and proof tools have been modified towards this
  6172     `standard'.
  6173 
  6174 * HOL/Lists:
  6175   the function "set_of_list" has been renamed "set" (and its theorems too);
  6176   the function "nth" now takes its arguments in the reverse order and
  6177   has acquired the infix notation "!" as in "xs!n".
  6178 
  6179 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6180 
  6181 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6182   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6183 
  6184 * HOL/record: extensible records with schematic structural subtyping
  6185 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6186 still lacks various theorems and concrete record syntax;
  6187 
  6188 
  6189 *** HOLCF ***
  6190 
  6191 * removed "axioms" and "generated by" sections;
  6192 
  6193 * replaced "ops" section by extended "consts" section, which is capable of
  6194   handling the continuous function space "->" directly;
  6195 
  6196 * domain package:
  6197   . proves theorems immediately and stores them in the theory,
  6198   . creates hierachical name space,
  6199   . now uses normal mixfix annotations (instead of cinfix...),
  6200   . minor changes to some names and values (for consistency),
  6201   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6202   . separator between mutual domain defs: changed "," to "and",
  6203   . improved handling of sort constraints;  now they have to
  6204     appear on the left-hand side of the equations only;
  6205 
  6206 * fixed LAM <x,y,zs>.b syntax;
  6207 
  6208 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6209 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6210 
  6211 
  6212 *** FOL and ZF ***
  6213 
  6214 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6215   with `addloop' of the simplifier to faciliate case splitting in premises.
  6216 
  6217 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6218 in HOL, they strip ALL and --> from proved theorems;
  6219 
  6220 
  6221 
  6222 New in Isabelle94-8 (May 1997)
  6223 ------------------------------
  6224 
  6225 *** General Changes ***
  6226 
  6227 * new utilities to build / run / maintain Isabelle etc. (in parts
  6228 still somewhat experimental); old Makefiles etc. still functional;
  6229 
  6230 * new 'Isabelle System Manual';
  6231 
  6232 * INSTALL text, together with ./configure and ./build scripts;
  6233 
  6234 * reimplemented type inference for greater efficiency, better error
  6235 messages and clean internal interface;
  6236 
  6237 * prlim command for dealing with lots of subgoals (an easier way of
  6238 setting goals_limit);
  6239 
  6240 
  6241 *** Syntax ***
  6242 
  6243 * supports alternative (named) syntax tables (parser and pretty
  6244 printer); internal interface is provided by add_modesyntax(_i);
  6245 
  6246 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6247 be used in conjunction with the Isabelle symbol font; uses the
  6248 "symbols" syntax table;
  6249 
  6250 * added token_translation interface (may translate name tokens in
  6251 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6252 the current print_mode); IMPORTANT: user print translation functions
  6253 are responsible