NEWS
author haftmann
Wed Sep 23 14:00:12 2009 +0200 (2009-09-23)
changeset 32657 5f13912245ff
parent 32642 026e7c6a6d08
child 32697 72e8608dce54
permissions -rw-r--r--
Code_Eval(uation)
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    10 one backslash should be used, even in ML sources.
    11 
    12 
    13 *** Pure ***
    14 
    15 * On instantiation of classes, remaining undefined class parameters
    16 are formally declared.  INCOMPATIBILITY.
    17 
    18 
    19 *** HOL ***
    20 
    21 * New proof method "smt" for a combination of first-order logic
    22 with equality, linear and nonlinear (natural/integer/real)
    23 arithmetic, and fixed-size bitvectors; there is also basic
    24 support for higher-order features (esp. lambda abstractions).
    25 It is an incomplete decision procedure based on external SMT
    26 solvers using the oracle mechanism.
    27 
    28 * Reorganization of number theory:
    29   * former session NumberTheory now named Old_Number_Theory
    30   * new session Number_Theory by Jeremy Avigad; if possible, prefer this.
    31   * moved legacy theories Legacy_GCD and Primes from Library/ to Old_Number_Theory/;
    32   * moved theory Pocklington from Library/ to Old_Number_Theory/;
    33   * removed various references to Old_Number_Theory from HOL distribution.
    34 INCOMPATIBILITY.
    35 
    36 * Theory GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm
    37 of finite and infinite sets. It is shown that they form a complete
    38 lattice.
    39 
    40 * Split off prime number ingredients from theory GCD
    41 to theory Number_Theory/Primes;
    42 
    43 * Class semiring_div requires superclass no_zero_divisors and proof of
    44 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    45 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    46 generalized to class semiring_div, subsuming former theorems
    47 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    48 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    49 INCOMPATIBILITY.
    50 
    51 * New testing tool "Mirabelle" for automated (proof) tools. Applies
    52 several tools and tactics like sledgehammer, metis, or quickcheck, to
    53 every proof step in a theory. To be used in batch mode via the
    54 "mirabelle" utility.
    55 
    56 * New proof method "sos" (sum of squares) for nonlinear real
    57 arithmetic (originally due to John Harison). It requires
    58 Library/Sum_Of_Squares.  It is not a complete decision procedure but
    59 works well in practice on quantifier-free real arithmetic with +, -,
    60 *, ^, =, <= and <, i.e. boolean combinations of equalities and
    61 inequalities between polynomials. It makes use of external
    62 semidefinite programming solvers.  For more information and examples
    63 see src/HOL/Library/Sum_Of_Squares.
    64 
    65 * Code generator attributes follow the usual underscore convention:
    66     code_unfold     replaces    code unfold
    67     code_post       replaces    code post
    68     etc.
    69   INCOMPATIBILITY.
    70 
    71 * Refinements to lattice classes and sets:
    72   - less default intro/elim rules in locale variant, more default
    73     intro/elim rules in class variant: more uniformity
    74   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    75   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    76   - renamed ACI to inf_sup_aci
    77   - new class "boolean_algebra"
    78   - class "complete_lattice" moved to separate theory "complete_lattice";
    79     corresponding constants (and abbreviations) renamed and with authentic syntax:
    80     Set.Inf ~>      Complete_Lattice.Inf
    81     Set.Sup ~>      Complete_Lattice.Sup
    82     Set.INFI ~>     Complete_Lattice.INFI
    83     Set.SUPR ~>     Complete_Lattice.SUPR
    84     Set.Inter ~>    Complete_Lattice.Inter
    85     Set.Union ~>    Complete_Lattice.Union
    86     Set.INTER ~>    Complete_Lattice.INTER
    87     Set.UNION ~>    Complete_Lattice.UNION
    88   - more convenient names for set intersection and union:
    89     Set.Int ~>      Set.inter
    90     Set.Un ~>       Set.union
    91   - authentic syntax for
    92     Set.Pow
    93     Set.image
    94   - mere abbreviations:
    95     Set.empty               (for bot)
    96     Set.UNIV                (for top)
    97     Complete_Lattice.Inter  (for Inf)
    98     Complete_Lattice.Union  (for Sup)
    99     Complete_Lattice.INTER  (for INFI)
   100     Complete_Lattice.UNION  (for SUPR)
   101   - object-logic definitions as far as appropriate
   102 
   103   INCOMPATIBILITY.
   104 
   105 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no
   106 simp rules by default any longer.  The same applies to
   107 min_max.inf_absorb1 etc.!  INCOMPATIBILITY.
   108 
   109 * Power operations on relations and functions are now one dedicate
   110 constant "compow" with infix syntax "^^".  Power operations on
   111 multiplicative monoids retains syntax "^" and is now defined generic
   112 in class power.  INCOMPATIBILITY.
   113 
   114 * Relation composition "R O S" now has a "more standard" argument
   115 order, i.e., "R O S = {(x,z). EX y. (x,y) : R & (y,z) : S }".
   116 INCOMPATIBILITY: Rewrite propositions with "S O R" --> "R O S". Proofs
   117 may occationally break, since the O_assoc rule was not rewritten like
   118 this.  Fix using O_assoc[symmetric].  The same applies to the curried
   119 version "R OO S".
   120 
   121 * ML antiquotation @{code_datatype} inserts definition of a datatype
   122 generated by the code generator; see Predicate.thy for an example.
   123 
   124 * New method "linarith" invokes existing linear arithmetic decision
   125 procedure only.
   126 
   127 * New implementation of quickcheck uses generic code generator;
   128 default generators are provided for all suitable HOL types, records
   129 and datatypes.
   130 
   131 * Renamed theorems:
   132 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   133 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   134 Suc_plus1 -> Suc_eq_plus1
   135 
   136 * Moved theorems:
   137 Wellfounded.in_inv_image -> Relation.in_inv_image
   138 
   139 * New sledgehammer option "Full Types" in Proof General settings menu.
   140 Causes full type information to be output to the ATPs.  This slows
   141 ATPs down considerably but eliminates a source of unsound "proofs"
   142 that fail later.
   143 
   144 * New method metisFT: A version of metis that uses full type information
   145 in order to avoid failures of proof reconstruction.
   146 
   147 * Discontinued ancient tradition to suffix certain ML module names
   148 with "_package", e.g.:
   149 
   150     DatatypePackage ~> Datatype
   151     InductivePackage ~> Inductive
   152 
   153 INCOMPATIBILITY.
   154 
   155 * Discontinued abbreviation "arbitrary" of constant
   156 "undefined". INCOMPATIBILITY, use "undefined" directly.
   157 
   158 * New evaluator "approximate" approximates an real valued term using
   159 the same method as the approximation method.
   160 
   161 * Method "approximate" supports now arithmetic expressions as
   162 boundaries of intervals and implements interval splitting and Taylor
   163 series expansion.
   164 
   165 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   166 the theorems in DERIV_intros assumes composition with an additional
   167 function and matches a variable to the derivative, which has to be
   168 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   169 the derivative of most elementary terms.
   170 
   171 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   172 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   173 
   174 
   175 *** ML ***
   176 
   177 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   178 parallel tactical reasoning.
   179 
   180 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   181 are similar to SUBPROOF, but are slightly more flexible: only the
   182 specified parts of the subgoal are imported into the context, and the
   183 body tactic may introduce new subgoals and schematic variables.
   184 
   185 * Old tactical METAHYPS, which does not observe the proof context, has
   186 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   187 or Subgoal.FOCUS etc.
   188 
   189 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   190 functors have their own ML name space there is no point to mark them
   191 separately.)  Minor INCOMPATIBILITY.
   192 
   193 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   194 
   195 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   196 cominators for "args".  INCOMPATIBILITY, need to use simplified
   197 Attrib/Method.setup introduced in Isabelle2009.
   198 
   199 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   200 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   201 last resort.  INCOMPATIBILITY.
   202 
   203 * Display.pretty_thm now requires a proper context (cf. former
   204 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   205 or even Display.pretty_thm_without_context as last resort.
   206 INCOMPATIBILITY.
   207 
   208 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   209 Syntax.pretty_typ/term directly, preferably with proper context
   210 instead of global theory.
   211 
   212 
   213 *** System ***
   214 
   215 * Support for additional "Isabelle components" via etc/components, see
   216 also the system manual.
   217 
   218 * The isabelle makeall tool now operates on all components with
   219 IsaMakefile, not just hardwired "logics".
   220 
   221 * Discontinued support for Poly/ML 4.x versions.
   222 
   223 * Removed "compress" option from isabelle-process and isabelle usedir;
   224 this is always enabled.
   225 
   226 * More fine-grained control of proof parallelism, cf.
   227 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   228 
   229 
   230 
   231 New in Isabelle2009 (April 2009)
   232 --------------------------------
   233 
   234 *** General ***
   235 
   236 * Simplified main Isabelle executables, with less surprises on
   237 case-insensitive file-systems (such as Mac OS).
   238 
   239   - The main Isabelle tool wrapper is now called "isabelle" instead of
   240     "isatool."
   241 
   242   - The former "isabelle" alias for "isabelle-process" has been
   243     removed (should rarely occur to regular users).
   244 
   245   - The former "isabelle-interface" and its alias "Isabelle" have been
   246     removed (interfaces are now regular Isabelle tools).
   247 
   248 Within scripts and make files, the Isabelle environment variables
   249 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   250 respectively.  (The latter are still available as legacy feature.)
   251 
   252 The old isabelle-interface wrapper could react in confusing ways if
   253 the interface was uninstalled or changed otherwise.  Individual
   254 interface tool configuration is now more explicit, see also the
   255 Isabelle system manual.  In particular, Proof General is now available
   256 via "isabelle emacs".
   257 
   258 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   259 purge installed copies of Isabelle executables and re-run "isabelle
   260 install -p ...", or use symlinks.
   261 
   262 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   263 old ~/isabelle, which was slightly non-standard and apt to cause
   264 surprises on case-insensitive file-systems (such as Mac OS).
   265 
   266 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   267 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   268 care is required when using older releases of Isabelle.  Note that
   269 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   270 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   271 
   272 * Proofs of fully specified statements are run in parallel on
   273 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   274 a regular 4-core machine, if the initial heap space is made reasonably
   275 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   276 
   277 * The main reference manuals ("isar-ref", "implementation", and
   278 "system") have been updated and extended.  Formally checked references
   279 as hyperlinks are now available uniformly.
   280 
   281 
   282 *** Pure ***
   283 
   284 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   285 respects.  The most important changes are listed below.  See the
   286 Tutorial on Locales ("locales" manual) for details.
   287 
   288 - In locale expressions, instantiation replaces renaming.  Parameters
   289 must be declared in a for clause.  To aid compatibility with previous
   290 parameter inheritance, in locale declarations, parameters that are not
   291 'touched' (instantiation position "_" or omitted) are implicitly added
   292 with their syntax at the beginning of the for clause.
   293 
   294 - Syntax from abbreviations and definitions in locales is available in
   295 locale expressions and context elements.  The latter is particularly
   296 useful in locale declarations.
   297 
   298 - More flexible mechanisms to qualify names generated by locale
   299 expressions.  Qualifiers (prefixes) may be specified in locale
   300 expressions, and can be marked as mandatory (syntax: "name!:") or
   301 optional (syntax "name?:").  The default depends for plain "name:"
   302 depends on the situation where a locale expression is used: in
   303 commands 'locale' and 'sublocale' prefixes are optional, in
   304 'interpretation' and 'interpret' prefixes are mandatory.  The old
   305 implicit qualifiers derived from the parameter names of a locale are
   306 no longer generated.
   307 
   308 - Command "sublocale l < e" replaces "interpretation l < e".  The
   309 instantiation clause in "interpretation" and "interpret" (square
   310 brackets) is no longer available.  Use locale expressions.
   311 
   312 - When converting proof scripts, mandatory qualifiers in
   313 'interpretation' and 'interpret' should be retained by default, even
   314 if this is an INCOMPATIBILITY compared to former behavior.  In the
   315 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   316 in locale expressions range over a single locale instance only.
   317 
   318 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   319 In existing theorem specifications replace the includes element by the
   320 respective context elements of the included locale, omitting those
   321 that are already present in the theorem specification.  Multiple
   322 assume elements of a locale should be replaced by a single one
   323 involving the locale predicate.  In the proof body, declarations (most
   324 notably theorems) may be regained by interpreting the respective
   325 locales in the proof context as required (command "interpret").
   326 
   327 If using "includes" in replacement of a target solely because the
   328 parameter types in the theorem are not as general as in the target,
   329 consider declaring a new locale with additional type constraints on
   330 the parameters (context element "constrains").
   331 
   332 - Discontinued "locale (open)".  INCOMPATIBILITY.
   333 
   334 - Locale interpretation commands no longer attempt to simplify goal.
   335 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   336 methods intro_locales and unfold_locales to clarify.
   337 
   338 - Locale interpretation commands no longer accept interpretation
   339 attributes.  INCOMPATIBILITY.
   340 
   341 * Class declaration: so-called "base sort" must not be given in import
   342 list any longer, but is inferred from the specification.  Particularly
   343 in HOL, write
   344 
   345     class foo = ...
   346 
   347 instead of
   348 
   349     class foo = type + ...
   350 
   351 * Class target: global versions of theorems stemming do not carry a
   352 parameter prefix any longer.  INCOMPATIBILITY.
   353 
   354 * Class 'instance' command no longer accepts attached definitions.
   355 INCOMPATIBILITY, use proper 'instantiation' target instead.
   356 
   357 * Recovered hiding of consts, which was accidentally broken in
   358 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   359 makes c inaccessible; consider using ``hide (open) const c'' instead.
   360 
   361 * Slightly more coherent Pure syntax, with updated documentation in
   362 isar-ref manual.  Removed locales meta_term_syntax and
   363 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   364 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   365 directly in regular applications.
   366 
   367 * There is a new syntactic category "float_const" for signed decimal
   368 fractions (e.g. 123.45 or -123.45).
   369 
   370 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   371 interface with 'setup' command instead.
   372 
   373 * Command 'local_setup' is similar to 'setup', but operates on a local
   374 theory context.
   375 
   376 * The 'axiomatization' command now only works within a global theory
   377 context.  INCOMPATIBILITY.
   378 
   379 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   380 hypotheses.  Sorts required in the course of reasoning need to be
   381 covered by the constraints in the initial statement, completed by the
   382 type instance information of the background theory.  Non-trivial sort
   383 hypotheses, which rarely occur in practice, may be specified via
   384 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   385 
   386   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   387 
   388 The result contains an implicit sort hypotheses as before --
   389 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   390 normalization.
   391 
   392 * Generalized Isar history, with support for linear undo, direct state
   393 addressing etc.
   394 
   395 * Changed defaults for unify configuration options:
   396 
   397   unify_trace_bound = 50 (formerly 25)
   398   unify_search_bound = 60 (formerly 30)
   399 
   400 * Different bookkeeping for code equations (INCOMPATIBILITY):
   401 
   402   a) On theory merge, the last set of code equations for a particular
   403      constant is taken (in accordance with the policy applied by other
   404      parts of the code generator framework).
   405 
   406   b) Code equations stemming from explicit declarations (e.g. code
   407      attribute) gain priority over default code equations stemming
   408      from definition, primrec, fun etc.
   409 
   410 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   411 
   412 * Unified theorem tables for both code generators.  Thus [code
   413 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   414 
   415 * Command 'find_consts' searches for constants based on type and name
   416 patterns, e.g.
   417 
   418     find_consts "_ => bool"
   419 
   420 By default, matching is against subtypes, but it may be restricted to
   421 the whole type.  Searching by name is possible.  Multiple queries are
   422 conjunctive and queries may be negated by prefixing them with a
   423 hyphen:
   424 
   425     find_consts strict: "_ => bool" name: "Int" -"int => int"
   426 
   427 * New 'find_theorems' criterion "solves" matches theorems that
   428 directly solve the current goal (modulo higher-order unification).
   429 
   430 * Auto solve feature for main theorem statements: whenever a new goal
   431 is stated, "find_theorems solves" is called; any theorems that could
   432 solve the lemma directly are listed as part of the goal state.
   433 Cf. associated options in Proof General Isabelle settings menu,
   434 enabled by default, with reasonable timeout for pathological cases of
   435 higher-order unification.
   436 
   437 
   438 *** Document preparation ***
   439 
   440 * Antiquotation @{lemma} now imitates a regular terminal proof,
   441 demanding keyword 'by' and supporting the full method expression
   442 syntax just like the Isar command 'by'.
   443 
   444 
   445 *** HOL ***
   446 
   447 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   448 points Main and Complex_Main remain as before.
   449 
   450 * Logic image HOL-Plain provides a minimal HOL with the most important
   451 tools available (inductive, datatype, primrec, ...).  This facilitates
   452 experimentation and tool development.  Note that user applications
   453 (and library theories) should never refer to anything below theory
   454 Main, as before.
   455 
   456 * Logic image HOL-Main stops at theory Main, and thus facilitates
   457 experimentation due to shorter build times.
   458 
   459 * Logic image HOL-NSA contains theories of nonstandard analysis which
   460 were previously part of former HOL-Complex.  Entry point Hyperreal
   461 remains valid, but theories formerly using Complex_Main should now use
   462 new entry point Hypercomplex.
   463 
   464 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   465 Posix processes.  Avoids potentially expensive forking of the ML
   466 process.  New thread-based implementation also works on non-Unix
   467 platforms (Cygwin).  Provers are no longer hardwired, but defined
   468 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   469 commands are covered in the isar-ref manual.
   470 
   471 * Wrapper scripts for remote SystemOnTPTP service allows to use
   472 sledgehammer without local ATP installation (Vampire etc.). Other
   473 provers may be included via suitable ML wrappers, see also
   474 src/HOL/ATP_Linkup.thy.
   475 
   476 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   477 menu.
   478 
   479 * The metis method no longer fails because the theorem is too trivial
   480 (contains the empty clause).
   481 
   482 * The metis method now fails in the usual manner, rather than raising
   483 an exception, if it determines that it cannot prove the theorem.
   484 
   485 * Method "coherent" implements a prover for coherent logic (see also
   486 src/Tools/coherent.ML).
   487 
   488 * Constants "undefined" and "default" replace "arbitrary".  Usually
   489 "undefined" is the right choice to replace "arbitrary", though
   490 logically there is no difference.  INCOMPATIBILITY.
   491 
   492 * Command "value" now integrates different evaluation mechanisms.  The
   493 result of the first successful evaluation mechanism is printed.  In
   494 square brackets a particular named evaluation mechanisms may be
   495 specified (currently, [SML], [code] or [nbe]).  See further
   496 src/HOL/ex/Eval_Examples.thy.
   497 
   498 * Normalization by evaluation now allows non-leftlinear equations.
   499 Declare with attribute [code nbe].
   500 
   501 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   502 as the structured Isar versions "cases" and "induct", cf. the
   503 corresponding "cases" and "induct" attributes.  Mutual induction rules
   504 are now presented as a list of individual projections
   505 (e.g. foo_bar.inducts for types foo and bar); the old format with
   506 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   507 rare situations a different rule is selected --- notably nested tuple
   508 elimination instead of former prod.exhaust: use explicit (case_tac t
   509 rule: prod.exhaust) here.
   510 
   511 * Attributes "cases", "induct", "coinduct" support "del" option.
   512 
   513 * Removed fact "case_split_thm", which duplicates "case_split".
   514 
   515 * The option datatype has been moved to a new theory Option.  Renamed
   516 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   517 
   518 * New predicate "strict_mono" classifies strict functions on partial
   519 orders.  With strict functions on linear orders, reasoning about
   520 (in)equalities is facilitated by theorems "strict_mono_eq",
   521 "strict_mono_less_eq" and "strict_mono_less".
   522 
   523 * Some set operations are now proper qualified constants with
   524 authentic syntax.  INCOMPATIBILITY:
   525 
   526     op Int ~>   Set.Int
   527     op Un ~>    Set.Un
   528     INTER ~>    Set.INTER
   529     UNION ~>    Set.UNION
   530     Inter ~>    Set.Inter
   531     Union ~>    Set.Union
   532     {} ~>       Set.empty
   533     UNIV ~>     Set.UNIV
   534 
   535 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   536 theory Set.
   537 
   538 * Auxiliary class "itself" has disappeared -- classes without any
   539 parameter are treated as expected by the 'class' command.
   540 
   541 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   542 
   543 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   544 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   545 
   546 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   547 method "approximation".  It proves formulas on real values by using
   548 interval arithmetic.  In the formulas are also the transcendental
   549 functions sin, cos, tan, atan, ln, exp and the constant pi are
   550 allowed. For examples see
   551 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   552 
   553 * Theory "Reflection" now resides in HOL/Library.
   554 
   555 * Entry point to Word library now simply named "Word".
   556 INCOMPATIBILITY.
   557 
   558 * Made source layout more coherent with logical distribution
   559 structure:
   560 
   561     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   562     src/HOL/Library/Code_Message.thy ~> src/HOL/
   563     src/HOL/Library/GCD.thy ~> src/HOL/
   564     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   565     src/HOL/Library/Parity.thy ~> src/HOL/
   566     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   567     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   568     src/HOL/Real/Lubs.thy ~> src/HOL/
   569     src/HOL/Real/PReal.thy ~> src/HOL/
   570     src/HOL/Real/Rational.thy ~> src/HOL/
   571     src/HOL/Real/RComplete.thy ~> src/HOL/
   572     src/HOL/Real/RealDef.thy ~> src/HOL/
   573     src/HOL/Real/RealPow.thy ~> src/HOL/
   574     src/HOL/Real/Real.thy ~> src/HOL/
   575     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   576     src/HOL/Complex/Complex.thy ~> src/HOL/
   577     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   578     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   579     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   580     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   581     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   582     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   583     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   584     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   585     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   586     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   587     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   588     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   589     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   590     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   591     src/HOL/Real/Float ~> src/HOL/Library/
   592     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   593     src/HOL/Real/RealVector.thy ~> src/HOL/
   594 
   595     src/HOL/arith_data.ML ~> src/HOL/Tools
   596     src/HOL/hologic.ML ~> src/HOL/Tools
   597     src/HOL/simpdata.ML ~> src/HOL/Tools
   598     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   599     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   600     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   601     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   602     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   603     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   604     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   605 
   606     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   607     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   608     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   609     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   610     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   611     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   612 
   613 * If methods "eval" and "evaluation" encounter a structured proof
   614 state with !!/==>, only the conclusion is evaluated to True (if
   615 possible), avoiding strange error messages.
   616 
   617 * Method "sizechange" automates termination proofs using (a
   618 modification of) the size-change principle.  Requires SAT solver.  See
   619 src/HOL/ex/Termination.thy for examples.
   620 
   621 * Simplifier: simproc for let expressions now unfolds if bound
   622 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   623 
   624 * Method "arith": Linear arithmetic now ignores all inequalities when
   625 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   626 
   627 * New attribute "arith" for facts that should always be used
   628 automatically by arithmetic. It is intended to be used locally in
   629 proofs, e.g.
   630 
   631   assumes [arith]: "x > 0"
   632 
   633 Global usage is discouraged because of possible performance impact.
   634 
   635 * New classes "top" and "bot" with corresponding operations "top" and
   636 "bot" in theory Orderings; instantiation of class "complete_lattice"
   637 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   638 
   639 * Changed definition lemma "less_fun_def" in order to provide an
   640 instance for preorders on functions; use lemma "less_le" instead.
   641 INCOMPATIBILITY.
   642 
   643 * Theory Orderings: class "wellorder" moved here, with explicit
   644 induction rule "less_induct" as assumption.  For instantiation of
   645 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   646 INCOMPATIBILITY.
   647 
   648 * Theory Orderings: added class "preorder" as superclass of "order".
   649 INCOMPATIBILITY: Instantiation proofs for order, linorder
   650 etc. slightly changed.  Some theorems named order_class.* now named
   651 preorder_class.*.
   652 
   653 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   654 "diag" to "Id_on".
   655 
   656 * Theory Finite_Set: added a new fold combinator of type
   657 
   658   ('a => 'b => 'b) => 'b => 'a set => 'b
   659 
   660 Occasionally this is more convenient than the old fold combinator
   661 which is now defined in terms of the new one and renamed to
   662 fold_image.
   663 
   664 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   665 and "ring_simps" have been replaced by "algebra_simps" (which can be
   666 extended with further lemmas!).  At the moment both still exist but
   667 the former will disappear at some point.
   668 
   669 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   670 class recpower.  Type-specific simp rules for various recpower types
   671 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   672 
   673 rat_power_0    -> power_0
   674 rat_power_Suc  -> power_Suc
   675 realpow_0      -> power_0
   676 realpow_Suc    -> power_Suc
   677 complexpow_0   -> power_0
   678 complexpow_Suc -> power_Suc
   679 power_poly_0   -> power_0
   680 power_poly_Suc -> power_Suc
   681 
   682 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   683 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   684 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   685 of lemmas from Divides has been generalized from nat to class
   686 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   687 renames resulting from duplicate elimination:
   688 
   689     dvd_def_mod ~>          dvd_eq_mod_eq_0
   690     zero_dvd_iff ~>         dvd_0_left_iff
   691     dvd_0 ~>                dvd_0_right
   692     DIVISION_BY_ZERO_DIV ~> div_by_0
   693     DIVISION_BY_ZERO_MOD ~> mod_by_0
   694     mult_div ~>             div_mult_self2_is_id
   695     mult_mod ~>             mod_mult_self2_is_0
   696 
   697 * Theory IntDiv: removed many lemmas that are instances of class-based
   698 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   699 rename old lemmas as follows:
   700 
   701 dvd_diff               -> nat_dvd_diff
   702 dvd_zminus_iff         -> dvd_minus_iff
   703 mod_add1_eq            -> mod_add_eq
   704 mod_mult1_eq           -> mod_mult_right_eq
   705 mod_mult1_eq'          -> mod_mult_left_eq
   706 mod_mult_distrib_mod   -> mod_mult_eq
   707 nat_mod_add_left_eq    -> mod_add_left_eq
   708 nat_mod_add_right_eq   -> mod_add_right_eq
   709 nat_mod_div_trivial    -> mod_div_trivial
   710 nat_mod_mod_trivial    -> mod_mod_trivial
   711 zdiv_zadd_self1        -> div_add_self1
   712 zdiv_zadd_self2        -> div_add_self2
   713 zdiv_zmult_self1       -> div_mult_self2_is_id
   714 zdiv_zmult_self2       -> div_mult_self1_is_id
   715 zdvd_triv_left         -> dvd_triv_left
   716 zdvd_triv_right        -> dvd_triv_right
   717 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   718 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   719 zmod_zadd_left_eq      -> mod_add_left_eq
   720 zmod_zadd_right_eq     -> mod_add_right_eq
   721 zmod_zadd_self1        -> mod_add_self1
   722 zmod_zadd_self2        -> mod_add_self2
   723 zmod_zadd1_eq          -> mod_add_eq
   724 zmod_zdiff1_eq         -> mod_diff_eq
   725 zmod_zdvd_zmod         -> mod_mod_cancel
   726 zmod_zmod_cancel       -> mod_mod_cancel
   727 zmod_zmult_self1       -> mod_mult_self2_is_0
   728 zmod_zmult_self2       -> mod_mult_self1_is_0
   729 zmod_1                 -> mod_by_1
   730 zdiv_1                 -> div_by_1
   731 zdvd_abs1              -> abs_dvd_iff
   732 zdvd_abs2              -> dvd_abs_iff
   733 zdvd_refl              -> dvd_refl
   734 zdvd_trans             -> dvd_trans
   735 zdvd_zadd              -> dvd_add
   736 zdvd_zdiff             -> dvd_diff
   737 zdvd_zminus_iff        -> dvd_minus_iff
   738 zdvd_zminus2_iff       -> minus_dvd_iff
   739 zdvd_zmultD            -> dvd_mult_right
   740 zdvd_zmultD2           -> dvd_mult_left
   741 zdvd_zmult_mono        -> mult_dvd_mono
   742 zdvd_0_right           -> dvd_0_right
   743 zdvd_0_left            -> dvd_0_left_iff
   744 zdvd_1_left            -> one_dvd
   745 zminus_dvd_iff         -> minus_dvd_iff
   746 
   747 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   748 
   749 * The real numbers offer decimal input syntax: 12.34 is translated
   750 into 1234/10^2. This translation is not reversed upon output.
   751 
   752 * Theory Library/Polynomial defines an abstract type 'a poly of
   753 univariate polynomials with coefficients of type 'a.  In addition to
   754 the standard ring operations, it also supports div and mod.  Code
   755 generation is also supported, using list-style constructors.
   756 
   757 * Theory Library/Inner_Product defines a class of real_inner for real
   758 inner product spaces, with an overloaded operation inner :: 'a => 'a
   759 => real.  Class real_inner is a subclass of real_normed_vector from
   760 theory RealVector.
   761 
   762 * Theory Library/Product_Vector provides instances for the product
   763 type 'a * 'b of several classes from RealVector and Inner_Product.
   764 Definitions of addition, subtraction, scalar multiplication, norms,
   765 and inner products are included.
   766 
   767 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   768 addition to the field operations, numerals and case syntax are also
   769 supported.
   770 
   771 * Theory Library/Diagonalize provides constructive version of Cantor's
   772 first diagonalization argument.
   773 
   774 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   775 zlcm (for int); carried together from various gcd/lcm developements in
   776 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   777 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   778 may recover tupled syntax as follows:
   779 
   780     hide (open) const gcd
   781     abbreviation gcd where
   782       "gcd == (%(a, b). GCD.gcd a b)"
   783     notation (output)
   784       GCD.gcd ("gcd '(_, _')")
   785 
   786 The same works for lcm, zgcd, zlcm.
   787 
   788 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   789 instantiations for algebraic structures.  Removed some duplicate
   790 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   791 
   792 * ML antiquotation @{code} takes a constant as argument and generates
   793 corresponding code in background and inserts name of the corresponding
   794 resulting ML value/function/datatype constructor binding in place.
   795 All occurrences of @{code} with a single ML block are generated
   796 simultaneously.  Provides a generic and safe interface for
   797 instrumentalizing code generation.  See
   798 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   799 In future you ought to refrain from ad-hoc compiling generated SML
   800 code on the ML toplevel.  Note that (for technical reasons) @{code}
   801 cannot refer to constants for which user-defined serializations are
   802 set.  Refer to the corresponding ML counterpart directly in that
   803 cases.
   804 
   805 * Command 'rep_datatype': instead of theorem names the command now
   806 takes a list of terms denoting the constructors of the type to be
   807 represented as datatype.  The characteristic theorems have to be
   808 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   809 have disappeared in favour of existing ones:
   810 
   811     unit_induct                 ~> unit.induct
   812     prod_induct                 ~> prod.induct
   813     sum_induct                  ~> sum.induct
   814     Suc_Suc_eq                  ~> nat.inject
   815     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   816 
   817 
   818 *** HOL-Algebra ***
   819 
   820 * New locales for orders and lattices where the equivalence relation
   821 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   822 locales use a record structure with field eq for the equivalence.
   823 
   824 * New theory of factorial domains.
   825 
   826 * Units_l_inv and Units_r_inv are now simp rules by default.
   827 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   828 and/or r_inv will now also require deletion of these lemmas.
   829 
   830 * Renamed the following theorems, INCOMPATIBILITY:
   831 
   832 UpperD ~> Upper_memD
   833 LowerD ~> Lower_memD
   834 least_carrier ~> least_closed
   835 greatest_carrier ~> greatest_closed
   836 greatest_Lower_above ~> greatest_Lower_below
   837 one_zero ~> carrier_one_zero
   838 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   839 
   840 
   841 *** HOL-Nominal ***
   842 
   843 * Nominal datatypes can now contain type-variables.
   844 
   845 * Commands 'nominal_inductive' and 'equivariance' work with local
   846 theory targets.
   847 
   848 * Nominal primrec can now works with local theory targets and its
   849 specification syntax now conforms to the general format as seen in
   850 'inductive' etc.
   851 
   852 * Method "perm_simp" honours the standard simplifier attributes
   853 (no_asm), (no_asm_use) etc.
   854 
   855 * The new predicate #* is defined like freshness, except that on the
   856 left hand side can be a set or list of atoms.
   857 
   858 * Experimental command 'nominal_inductive2' derives strong induction
   859 principles for inductive definitions.  In contrast to
   860 'nominal_inductive', which can only deal with a fixed number of
   861 binders, it can deal with arbitrary expressions standing for sets of
   862 atoms to be avoided.  The only inductive definition we have at the
   863 moment that needs this generalisation is the typing rule for Lets in
   864 the algorithm W:
   865 
   866  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   867  -----------------------------------------------------------------
   868          Gamma |- Let x be t1 in t2 : T2
   869 
   870 In this rule one wants to avoid all the binders that are introduced by
   871 "close Gamma T1".  We are looking for other examples where this
   872 feature might be useful.  Please let us know.
   873 
   874 
   875 *** HOLCF ***
   876 
   877 * Reimplemented the simplification procedure for proving continuity
   878 subgoals.  The new simproc is extensible; users can declare additional
   879 continuity introduction rules with the attribute [cont2cont].
   880 
   881 * The continuity simproc now uses a different introduction rule for
   882 solving continuity subgoals on terms with lambda abstractions.  In
   883 some rare cases the new simproc may fail to solve subgoals that the
   884 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   885 Potential INCOMPATIBILITY.
   886 
   887 * Command 'fixrec': specification syntax now conforms to the general
   888 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   889 examples.  INCOMPATIBILITY.
   890 
   891 
   892 *** ZF ***
   893 
   894 * Proof of Zorn's Lemma for partial orders.
   895 
   896 
   897 *** ML ***
   898 
   899 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   900 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   901 depends on multithreading, so timouts will not work before Poly/ML
   902 5.2.1!
   903 
   904 * High-level support for concurrent ML programming, see
   905 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   906 particularly convenient to organize independent functional
   907 computations.  The concept of "synchronized variables" provides a
   908 higher-order interface for components with shared state, avoiding the
   909 delicate details of mutexes and condition variables.  (Requires
   910 Poly/ML 5.2.1 or later.)
   911 
   912 * ML bindings produced via Isar commands are stored within the Isar
   913 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   914 become thread-safe and work with undo as expected (concerning
   915 top-level bindings, not side-effects on global references).
   916 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   917 compiler at runtime; really global bindings need to be given outside a
   918 theory.  (Requires Poly/ML 5.2 or later.)
   919 
   920 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   921 context.  Top-level ML bindings are stored within the proof context in
   922 a purely sequential fashion, disregarding the nested proof structure.
   923 ML bindings introduced by 'ML_prf' are discarded at the end of the
   924 proof.  (Requires Poly/ML 5.2 or later.)
   925 
   926 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   927 and Method.setup, as well as Isar commands 'attribute_setup' and
   928 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   929 existing code accordingly, or use plain 'setup' together with old
   930 Method.add_method.
   931 
   932 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   933 to 'a -> thm, while results are always tagged with an authentic oracle
   934 name.  The Isar command 'oracle' is now polymorphic, no argument type
   935 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   936 accordingly.  Note that extra performance may be gained by producing
   937 the cterm carefully, avoiding slow Thm.cterm_of.
   938 
   939 * Simplified interface for defining document antiquotations via
   940 ThyOutput.antiquotation, ThyOutput.output, and optionally
   941 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   942 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   943 examples.
   944 
   945 * More systematic treatment of long names, abstract name bindings, and
   946 name space operations.  Basic operations on qualified names have been
   947 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   948 Long_Name.append.  Old type bstring has been mostly replaced by
   949 abstract type binding (see structure Binding), which supports precise
   950 qualification by packages and local theory targets, as well as proper
   951 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   952 bstring values into Binding.name, or better pass through abstract
   953 bindings everywhere.  See further src/Pure/General/long_name.ML,
   954 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   955 
   956 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   957 LocalTheory.note etc.) now refer to the *full* internal name, not the
   958 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   959 
   960 * Disposed old type and term read functions (Sign.read_def_typ,
   961 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   962 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   963 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   964 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   965 resort for legacy applications.
   966 
   967 * Disposed old declarations, tactics, tactic combinators that refer to
   968 the simpset or claset of an implicit theory (such as Addsimps,
   969 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   970 embedded ML text, or local_simpset_of with a proper context passed as
   971 explicit runtime argument.
   972 
   973 * Rules and tactics that read instantiations (read_instantiate,
   974 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   975 context, which is required for parsing and type-checking.  Moreover,
   976 the variables are specified as plain indexnames, not string encodings
   977 thereof.  INCOMPATIBILITY.
   978 
   979 * Generic Toplevel.add_hook interface allows to analyze the result of
   980 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   981 for theorem dependency output of transactions resulting in a new
   982 theory state.
   983 
   984 * ML antiquotations: block-structured compilation context indicated by
   985 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   986 
   987   @{binding name}                         - basic name binding
   988   @{let ?pat = term}                      - term abbreviation (HO matching)
   989   @{note name = fact}                     - fact abbreviation
   990   @{thm fact}                             - singleton fact (with attributes)
   991   @{thms fact}                            - general fact (with attributes)
   992   @{lemma prop by method}                 - singleton goal
   993   @{lemma prop by meth1 meth2}            - singleton goal
   994   @{lemma prop1 ... propN by method}      - general goal
   995   @{lemma prop1 ... propN by meth1 meth2} - general goal
   996   @{lemma (open) ...}                     - open derivation
   997 
   998 
   999 *** System ***
  1000 
  1001 * The Isabelle "emacs" tool provides a specific interface to invoke
  1002 Proof General / Emacs, with more explicit failure if that is not
  1003 installed (the old isabelle-interface script silently falls back on
  1004 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1005 installation location of the Proof General distribution.
  1006 
  1007 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1008 the Isabelle process into a JVM/Scala application.  See
  1009 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1010 process wrapper has been discontinued.)
  1011 
  1012 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1013 
  1014 * Various status messages (with exact source position information) are
  1015 emitted, if proper markup print mode is enabled.  This allows
  1016 user-interface components to provide detailed feedback on internal
  1017 prover operations.
  1018 
  1019 
  1020 
  1021 New in Isabelle2008 (June 2008)
  1022 -------------------------------
  1023 
  1024 *** General ***
  1025 
  1026 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1027 and updated, with formally checked references as hyperlinks.
  1028 
  1029 * Theory loader: use_thy (and similar operations) no longer set the
  1030 implicit ML context, which was occasionally hard to predict and in
  1031 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1032 provides a proper context already.
  1033 
  1034 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1035 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1036 'use' within a theory file will do the job.
  1037 
  1038 * Name space merge now observes canonical order, i.e. the second space
  1039 is inserted into the first one, while existing entries in the first
  1040 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1041 swap theory imports.
  1042 
  1043 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1044 INCOMPATIBILITY in identifier syntax etc.
  1045 
  1046 * Outer syntax: string tokens no longer admit escaped white space,
  1047 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1048 white space without escapes.
  1049 
  1050 * Outer syntax: string tokens may contain arbitrary character codes
  1051 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1052 "foo_bar".
  1053 
  1054 
  1055 *** Pure ***
  1056 
  1057 * Context-dependent token translations.  Default setup reverts locally
  1058 fixed variables, and adds hilite markup for undeclared frees.
  1059 
  1060 * Unused theorems can be found using the new command 'unused_thms'.
  1061 There are three ways of invoking it:
  1062 
  1063 (1) unused_thms
  1064      Only finds unused theorems in the current theory.
  1065 
  1066 (2) unused_thms thy_1 ... thy_n -
  1067      Finds unused theorems in the current theory and all of its ancestors,
  1068      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1069 
  1070 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1071      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1072      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1073      their ancestors.
  1074 
  1075 In order to increase the readability of the list produced by
  1076 unused_thms, theorems that have been created by a particular instance
  1077 of a theory command such as 'inductive' or 'function' are considered
  1078 to belong to the same "group", meaning that if at least one theorem in
  1079 this group is used, the other theorems in the same group are no longer
  1080 reported as unused.  Moreover, if all theorems in the group are
  1081 unused, only one theorem in the group is displayed.
  1082 
  1083 Note that proof objects have to be switched on in order for
  1084 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1085 usually the case when using Proof General with the default settings).
  1086 
  1087 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1088 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1089 duplicate fact bindings, or even accidental fact duplications.  Note
  1090 that tools may maintain dynamically scoped facts systematically, using
  1091 PureThy.add_thms_dynamic.
  1092 
  1093 * Command 'hide' now allows to hide from "fact" name space as well.
  1094 
  1095 * Eliminated destructive theorem database, simpset, claset, and
  1096 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1097 update of theories within ML code.
  1098 
  1099 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1100 INCOMPATIBILITY, object-logics depending on former Pure require
  1101 additional setup PureThy.old_appl_syntax_setup; object-logics
  1102 depending on former CPure need to refer to Pure.
  1103 
  1104 * Commands 'use' and 'ML' are now purely functional, operating on
  1105 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1106 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1107 INCOMPATIBILITY.
  1108 
  1109 * Command 'setup': discontinued implicit version with ML reference.
  1110 
  1111 * Instantiation target allows for simultaneous specification of class
  1112 instance operations together with an instantiation proof.
  1113 Type-checking phase allows to refer to class operations uniformly.
  1114 See src/HOL/Complex/Complex.thy for an Isar example and
  1115 src/HOL/Library/Eval.thy for an ML example.
  1116 
  1117 * Indexing of literal facts: be more serious about including only
  1118 facts from the visible specification/proof context, but not the
  1119 background context (locale etc.).  Affects `prop` notation and method
  1120 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1121 situations.
  1122 
  1123 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1124 "(open)" option, which used to expose internal bound variables to the
  1125 proof text.
  1126 
  1127 * Isar statements: removed obsolete case "rule_context".
  1128 INCOMPATIBILITY, better use explicit fixes/assumes.
  1129 
  1130 * Locale proofs: default proof step now includes 'unfold_locales';
  1131 hence 'proof' without argument may be used to unfold locale
  1132 predicates.
  1133 
  1134 
  1135 *** Document preparation ***
  1136 
  1137 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1138 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1139 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1140 spot); renamed link color from "darkblue" to "linkcolor" (default
  1141 value unchanged, can be redefined via \definecolor); no longer sets
  1142 "a4paper" option (unnecessary or even intrusive).
  1143 
  1144 * Antiquotation @{lemma A method} proves proposition A by the given
  1145 method (either a method name or a method name plus (optional) method
  1146 arguments in parentheses) and prints A just like @{prop A}.
  1147 
  1148 
  1149 *** HOL ***
  1150 
  1151 * New primrec package.  Specification syntax conforms in style to
  1152 definition/function/....  No separate induction rule is provided.  The
  1153 "primrec" command distinguishes old-style and new-style specifications
  1154 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1155 When adjusting theories, beware: constants stemming from new-style
  1156 primrec specifications have authentic syntax.
  1157 
  1158 * Metis prover is now an order of magnitude faster, and also works
  1159 with multithreading.
  1160 
  1161 * Metis: the maximum number of clauses that can be produced from a
  1162 theorem is now given by the attribute max_clauses.  Theorems that
  1163 exceed this number are ignored, with a warning printed.
  1164 
  1165 * Sledgehammer no longer produces structured proofs by default. To
  1166 enable, declare [[sledgehammer_full = true]].  Attributes
  1167 reconstruction_modulus, reconstruction_sorts renamed
  1168 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1169 
  1170 * Method "induct_scheme" derives user-specified induction rules
  1171 from well-founded induction and completeness of patterns. This factors
  1172 out some operations that are done internally by the function package
  1173 and makes them available separately.  See
  1174 src/HOL/ex/Induction_Scheme.thy for examples.
  1175 
  1176 * More flexible generation of measure functions for termination
  1177 proofs: Measure functions can be declared by proving a rule of the
  1178 form "is_measure f" and giving it the [measure_function] attribute.
  1179 The "is_measure" predicate is logically meaningless (always true), and
  1180 just guides the heuristic.  To find suitable measure functions, the
  1181 termination prover sets up the goal "is_measure ?f" of the appropriate
  1182 type and generates all solutions by prolog-style backwards proof using
  1183 the declared rules.
  1184 
  1185 This setup also deals with rules like 
  1186 
  1187   "is_measure f ==> is_measure (list_size f)"
  1188 
  1189 which accommodates nested datatypes that recurse through lists.
  1190 Similar rules are predeclared for products and option types.
  1191 
  1192 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1193 
  1194   INCOMPATIBILITIES:
  1195 
  1196   - Definitions of overloaded constants on sets have to be replaced by
  1197     definitions on => and bool.
  1198 
  1199   - Some definitions of overloaded operators on sets can now be proved
  1200     using the definitions of the operators on => and bool.  Therefore,
  1201     the following theorems have been renamed:
  1202 
  1203       subset_def   -> subset_eq
  1204       psubset_def  -> psubset_eq
  1205       set_diff_def -> set_diff_eq
  1206       Compl_def    -> Compl_eq
  1207       Sup_set_def  -> Sup_set_eq
  1208       Inf_set_def  -> Inf_set_eq
  1209       sup_set_def  -> sup_set_eq
  1210       inf_set_def  -> inf_set_eq
  1211 
  1212   - Due to the incompleteness of the HO unification algorithm, some
  1213     rules such as subst may require manual instantiation, if some of
  1214     the unknowns in the rule is a set.
  1215 
  1216   - Higher order unification and forward proofs:
  1217     The proof pattern
  1218 
  1219       have "P (S::'a set)" <...>
  1220       then have "EX S. P S" ..
  1221 
  1222     no longer works (due to the incompleteness of the HO unification
  1223     algorithm) and must be replaced by the pattern
  1224 
  1225       have "EX S. P S"
  1226       proof
  1227         show "P S" <...>
  1228       qed
  1229 
  1230   - Calculational reasoning with subst (or similar rules):
  1231     The proof pattern
  1232 
  1233       have "P (S::'a set)" <...>
  1234       also have "S = T" <...>
  1235       finally have "P T" .
  1236 
  1237     no longer works (for similar reasons as the previous example) and
  1238     must be replaced by something like
  1239 
  1240       have "P (S::'a set)" <...>
  1241       moreover have "S = T" <...>
  1242       ultimately have "P T" by simp
  1243 
  1244   - Tactics or packages written in ML code:
  1245     Code performing pattern matching on types via
  1246 
  1247       Type ("set", [T]) => ...
  1248 
  1249     must be rewritten. Moreover, functions like strip_type or
  1250     binder_types no longer return the right value when applied to a
  1251     type of the form
  1252 
  1253       T1 => ... => Tn => U => bool
  1254 
  1255     rather than
  1256 
  1257       T1 => ... => Tn => U set
  1258 
  1259 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1260 Wellfounded_Relations to theory Wellfounded.
  1261 
  1262 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1263 
  1264 * Class finite no longer treats UNIV as class parameter.  Use class
  1265 enum from theory Library/Enum instead to achieve a similar effect.
  1266 INCOMPATIBILITY.
  1267 
  1268 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1269 and "Cons".  INCOMPATIBILITY.
  1270 
  1271 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1272 Potential INCOMPATIBILITY.
  1273 
  1274 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1275 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1276 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1277 
  1278 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1279 the same name in theory Orderings:
  1280 
  1281   less_trans
  1282   less_linear
  1283   le_imp_less_or_eq
  1284   le_less_trans
  1285   less_le_trans
  1286   less_not_sym
  1287   less_asym
  1288 
  1289 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1290 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1291 and different variable names.
  1292 
  1293 * Library/Option_ord.thy: Canonical order on option type.
  1294 
  1295 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1296 finite maps.
  1297 
  1298 * Library/Countable.thy: Type class for countable types.
  1299 
  1300 * Theory Int: The representation of numerals has changed.  The infix
  1301 operator BIT and the bit datatype with constructors B0 and B1 have
  1302 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1303 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1304 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1305 accordingly.
  1306 
  1307 * Theory Nat: definition of <= and < on natural numbers no longer
  1308 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1309 le_def and less_def have disappeared.  Consider lemmas not_less
  1310 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1311 
  1312 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1313 (whose purpose mainly is for various fold_set functionals) have been
  1314 abandoned in favor of the existing algebraic classes
  1315 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1316 lower_semilattice (resp. upper_semilattice) and linorder.
  1317 INCOMPATIBILITY.
  1318 
  1319 * Theory Transitive_Closure: induct and cases rules now declare proper
  1320 case_names ("base" and "step").  INCOMPATIBILITY.
  1321 
  1322 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1323 lattices.  The form set-specific version is available as
  1324 Inductive.lfp_ordinal_induct_set.
  1325 
  1326 * Renamed theorems "power.simps" to "power_int.simps".
  1327 INCOMPATIBILITY.
  1328 
  1329 * Class semiring_div provides basic abstract properties of semirings
  1330 with division and modulo operations.  Subsumes former class dvd_mod.
  1331 
  1332 * Merged theories IntDef, Numeral and IntArith into unified theory
  1333 Int.  INCOMPATIBILITY.
  1334 
  1335 * Theory Library/Code_Index: type "index" now represents natural
  1336 numbers rather than integers.  INCOMPATIBILITY.
  1337 
  1338 * New class "uminus" with operation "uminus" (split of from class
  1339 "minus" which now only has operation "minus", binary).
  1340 INCOMPATIBILITY.
  1341 
  1342 * Constants "card", "internal_split", "option_map" now with authentic
  1343 syntax.  INCOMPATIBILITY.
  1344 
  1345 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1346 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1347 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1348 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1349 Sup_set_def, le_def, less_def, option_map_def now with object
  1350 equality.  INCOMPATIBILITY.
  1351 
  1352 * Records. Removed K_record, and replaced it by pure lambda term
  1353 %x. c. The simplifier setup is now more robust against eta expansion.
  1354 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1355 
  1356 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1357 
  1358 * Library/ListVector: new theory of arithmetic vector operations.
  1359 
  1360 * Library/Order_Relation: new theory of various orderings as sets of
  1361 pairs.  Defines preorders, partial orders, linear orders and
  1362 well-orders on sets and on types.
  1363 
  1364 
  1365 *** ZF ***
  1366 
  1367 * Renamed some theories to allow to loading both ZF and HOL in the
  1368 same session:
  1369 
  1370   Datatype  -> Datatype_ZF
  1371   Inductive -> Inductive_ZF
  1372   Int       -> Int_ZF
  1373   IntDiv    -> IntDiv_ZF
  1374   Nat       -> Nat_ZF
  1375   List      -> List_ZF
  1376   Main      -> Main_ZF
  1377 
  1378 INCOMPATIBILITY: ZF theories that import individual theories below
  1379 Main might need to be adapted.  Regular theory Main is still
  1380 available, as trivial extension of Main_ZF.
  1381 
  1382 
  1383 *** ML ***
  1384 
  1385 * ML within Isar: antiquotation @{const name} or @{const
  1386 name(typargs)} produces statically-checked Const term.
  1387 
  1388 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1389 (of the same name).  Removed obsolete print command.
  1390 
  1391 * Removed obsolete "use_legacy_bindings" function.
  1392 
  1393 * The ``print mode'' is now a thread-local value derived from a global
  1394 template (the former print_mode reference), thus access becomes
  1395 non-critical.  The global print_mode reference is for session
  1396 management only; user-code should use print_mode_value,
  1397 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1398 
  1399 * Functions system/system_out provide a robust way to invoke external
  1400 shell commands, with propagation of interrupts (requires Poly/ML
  1401 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1402 
  1403 
  1404 *** System ***
  1405 
  1406 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1407 in accordance with Proof General 3.7, which prefers GNU emacs.
  1408 
  1409 * isatool tty runs Isabelle process with plain tty interaction;
  1410 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1411 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1412 
  1413 * isatool browser now works with Cygwin as well, using general
  1414 "javapath" function defined in Isabelle process environment.
  1415 
  1416 * YXML notation provides a simple and efficient alternative to
  1417 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1418 isatool yxml as described in the Isabelle system manual.
  1419 
  1420 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1421 provides general wrapper for managing an Isabelle process in a robust
  1422 fashion, with ``cooked'' output from stdin/stderr.
  1423 
  1424 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1425 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1426 
  1427 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1428 way of changing the user's settings is via
  1429 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1430 script.
  1431 
  1432 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1433 cores of the underlying machine, which is a good starting point for
  1434 optimal performance tuning.  The corresponding usedir option -M allows
  1435 "max" as an alias for "0".  WARNING: does not work on certain versions
  1436 of Mac OS (with Poly/ML 5.1).
  1437 
  1438 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1439 adverse effect of Isabelle flooding interactive front-ends (notably
  1440 ProofGeneral / XEmacs).
  1441 
  1442 
  1443 
  1444 New in Isabelle2007 (November 2007)
  1445 -----------------------------------
  1446 
  1447 *** General ***
  1448 
  1449 * More uniform information about legacy features, notably a
  1450 warning/error of "Legacy feature: ...", depending on the state of the
  1451 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1452 legacy features will disappear eventually.
  1453 
  1454 * Theory syntax: the header format ``theory A = B + C:'' has been
  1455 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1456 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1457 
  1458 * Theory syntax: the old non-Isar theory file format has been
  1459 discontinued altogether.  Note that ML proof scripts may still be used
  1460 with Isar theories; migration is usually quite simple with the ML
  1461 function use_legacy_bindings.  INCOMPATIBILITY.
  1462 
  1463 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1464 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1465 quotes.
  1466 
  1467 * Theory loader: be more serious about observing the static theory
  1468 header specifications (including optional directories), but not the
  1469 accidental file locations of previously successful loads.  The strict
  1470 update policy of former update_thy is now already performed by
  1471 use_thy, so the former has been removed; use_thys updates several
  1472 theories simultaneously, just as 'imports' within a theory header
  1473 specification, but without merging the results.  Potential
  1474 INCOMPATIBILITY: may need to refine theory headers and commands
  1475 ROOT.ML which depend on load order.
  1476 
  1477 * Theory loader: optional support for content-based file
  1478 identification, instead of the traditional scheme of full physical
  1479 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1480 (cf. the system manual).  The new scheme allows to work with
  1481 non-finished theories in persistent session images, such that source
  1482 files may be moved later on without requiring reloads.
  1483 
  1484 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1485 file (with the same base name as the theory) are considered a legacy
  1486 feature, which will disappear eventually. Even now, the theory loader
  1487 no longer maintains dependencies on such files.
  1488 
  1489 * Syntax: the scope for resolving ambiguities via type-inference is
  1490 now limited to individual terms, instead of whole simultaneous
  1491 specifications as before. This greatly reduces the complexity of the
  1492 syntax module and improves flexibility by separating parsing and
  1493 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1494 'fixes' etc.) are required in rare situations.
  1495 
  1496 * Syntax: constants introduced by new-style packages ('definition',
  1497 'abbreviation' etc.) are passed through the syntax module in
  1498 ``authentic mode''. This means that associated mixfix annotations
  1499 really stick to such constants, independently of potential name space
  1500 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1501 trees are represented slightly differently, may need to adapt syntax
  1502 translations accordingly. Use CONST marker in 'translations' and
  1503 @{const_syntax} antiquotation in 'parse_translation' etc.
  1504 
  1505 * Legacy goal package: reduced interface to the bare minimum required
  1506 to keep existing proof scripts running.  Most other user-level
  1507 functions are now part of the OldGoals structure, which is *not* open
  1508 by default (consider isatool expandshort before open OldGoals).
  1509 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1510 these tend to cause confusion about the actual goal (!) context being
  1511 used here, which is not necessarily the same as the_context().
  1512 
  1513 * Command 'find_theorems': supports "*" wild-card in "name:"
  1514 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1515 support a specific search form (see ProofGeneral/CHANGES).
  1516 
  1517 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1518 by default, which means that "prems" (and also "fixed variables") are
  1519 suppressed from proof state output.  Note that the ProofGeneral
  1520 settings mechanism allows to change and save options persistently, but
  1521 older versions of Isabelle will fail to start up if a negative prems
  1522 limit is imposed.
  1523 
  1524 * Local theory targets may be specified by non-nested blocks of
  1525 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1526 contain definitions, theorems etc., including any derived mechanism
  1527 that has been implemented on top of these primitives.  This concept
  1528 generalizes the existing ``theorem (in ...)'' towards more versatility
  1529 and scalability.
  1530 
  1531 * Proof General interface: proper undo of final 'end' command;
  1532 discontinued Isabelle/classic mode (ML proof scripts).
  1533 
  1534 
  1535 *** Document preparation ***
  1536 
  1537 * Added antiquotation @{theory name} which prints the given name,
  1538 after checking that it refers to a valid ancestor theory in the
  1539 current context.
  1540 
  1541 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1542 check the given source text as ML type/structure, printing verbatim.
  1543 
  1544 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1545 "c args == rhs" given in the current context.  (Any number of
  1546 arguments may be given on the LHS.)
  1547 
  1548 
  1549 *** Pure ***
  1550 
  1551 * The 'class' package offers a combination of axclass and locale to
  1552 achieve Haskell-like type classes in Isabelle.  Definitions and
  1553 theorems within a class context produce both relative results (with
  1554 implicit parameters according to the locale context), and polymorphic
  1555 constants with qualified polymorphism (according to the class
  1556 context).  Within the body context of a 'class' target, a separate
  1557 syntax layer ("user space type system") takes care of converting
  1558 between global polymorphic consts and internal locale representation.
  1559 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1560 "isatool doc classes" provides a tutorial.
  1561 
  1562 * Generic code generator framework allows to generate executable
  1563 code for ML and Haskell (including Isabelle classes).  A short usage
  1564 sketch:
  1565 
  1566     internal compilation:
  1567         export_code <list of constants (term syntax)> in SML
  1568     writing SML code to a file:
  1569         export_code <list of constants (term syntax)> in SML <filename>
  1570     writing OCaml code to a file:
  1571         export_code <list of constants (term syntax)> in OCaml <filename>
  1572     writing Haskell code to a bunch of files:
  1573         export_code <list of constants (term syntax)> in Haskell <filename>
  1574 
  1575     evaluating closed propositions to True/False using code generation:
  1576         method ``eval''
  1577 
  1578 Reasonable default setup of framework in HOL.
  1579 
  1580 Theorem attributs for selecting and transforming function equations theorems:
  1581 
  1582     [code fun]:        select a theorem as function equation for a specific constant
  1583     [code fun del]:    deselect a theorem as function equation for a specific constant
  1584     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1585     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1586 
  1587 User-defined serializations (target in {SML, OCaml, Haskell}):
  1588 
  1589     code_const <and-list of constants (term syntax)>
  1590       {(target) <and-list of const target syntax>}+
  1591 
  1592     code_type <and-list of type constructors>
  1593       {(target) <and-list of type target syntax>}+
  1594 
  1595     code_instance <and-list of instances>
  1596       {(target)}+
  1597         where instance ::= <type constructor> :: <class>
  1598 
  1599     code_class <and_list of classes>
  1600       {(target) <and-list of class target syntax>}+
  1601         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1602 
  1603 code_instance and code_class only are effective to target Haskell.
  1604 
  1605 For example usage see src/HOL/ex/Codegenerator.thy and
  1606 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1607 generation from Isabelle/HOL theories is available via "isatool doc
  1608 codegen".
  1609 
  1610 * Code generator: consts in 'consts_code' Isar commands are now
  1611 referred to by usual term syntax (including optional type
  1612 annotations).
  1613 
  1614 * Command 'no_translations' removes translation rules from theory
  1615 syntax.
  1616 
  1617 * Overloaded definitions are now actually checked for acyclic
  1618 dependencies.  The overloading scheme is slightly more general than
  1619 that of Haskell98, although Isabelle does not demand an exact
  1620 correspondence to type class and instance declarations.
  1621 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1622 exotic versions of overloading -- at the discretion of the user!
  1623 
  1624 Polymorphic constants are represented via type arguments, i.e. the
  1625 instantiation that matches an instance against the most general
  1626 declaration given in the signature.  For example, with the declaration
  1627 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1628 as c(nat).  Overloading is essentially simultaneous structural
  1629 recursion over such type arguments.  Incomplete specification patterns
  1630 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1631 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1632 Command 'print_theory' outputs the normalized system of recursive
  1633 equations, see section "definitions".
  1634 
  1635 * Configuration options are maintained within the theory or proof
  1636 context (with name and type bool/int/string), providing a very simple
  1637 interface to a poor-man's version of general context data.  Tools may
  1638 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1639 these values using Config.get etc.  Users may change options via an
  1640 associated attribute of the same name.  This form of context
  1641 declaration works particularly well with commands 'declare' or
  1642 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1643 very easy to avoid global references, which would not observe Isar
  1644 toplevel undo/redo and fail to work with multithreading.
  1645 
  1646 Various global ML references of Pure and HOL have been turned into
  1647 configuration options:
  1648 
  1649   Unify.search_bound		unify_search_bound
  1650   Unify.trace_bound		unify_trace_bound
  1651   Unify.trace_simp		unify_trace_simp
  1652   Unify.trace_types		unify_trace_types
  1653   Simplifier.simp_depth_limit	simp_depth_limit
  1654   Blast.depth_limit		blast_depth_limit
  1655   DatatypeProp.dtK		datatype_distinctness_limit
  1656   fast_arith_neq_limit  	fast_arith_neq_limit
  1657   fast_arith_split_limit	fast_arith_split_limit
  1658 
  1659 * Named collections of theorems may be easily installed as context
  1660 data using the functor NamedThmsFun (see also
  1661 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1662 attributes; there is also a toplevel print command.  This facility is
  1663 just a common case of general context data, which is the preferred way
  1664 for anything more complex than just a list of facts in canonical
  1665 order.
  1666 
  1667 * Isar: command 'declaration' augments a local theory by generic
  1668 declaration functions written in ML.  This enables arbitrary content
  1669 being added to the context, depending on a morphism that tells the
  1670 difference of the original declaration context wrt. the application
  1671 context encountered later on.
  1672 
  1673 * Isar: proper interfaces for simplification procedures.  Command
  1674 'simproc_setup' declares named simprocs (with match patterns, and body
  1675 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1676 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1677 
  1678 * Isar: an extra pair of brackets around attribute declarations
  1679 abbreviates a theorem reference involving an internal dummy fact,
  1680 which will be ignored later --- only the effect of the attribute on
  1681 the background context will persist.  This form of in-place
  1682 declarations is particularly useful with commands like 'declare' and
  1683 'using', for example ``have A using [[simproc a]] by simp''.
  1684 
  1685 * Isar: method "assumption" (and implicit closing of subproofs) now
  1686 takes simple non-atomic goal assumptions into account: after applying
  1687 an assumption as a rule the resulting subgoals are solved by atomic
  1688 assumption steps.  This is particularly useful to finish 'obtain'
  1689 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1690 without referring to the original premise "!!x. P x ==> thesis" in the
  1691 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1692 more permissive.
  1693 
  1694 * Isar: implicit use of prems from the Isar proof context is
  1695 considered a legacy feature.  Common applications like ``have A .''
  1696 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1697 referencing facts explicitly here improves readability and
  1698 maintainability of proof texts.
  1699 
  1700 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1701 the obtained context from the course of reasoning!  For example:
  1702 
  1703   assume "EX x y. A x & B y"   -- "any previous fact"
  1704   then guess x and y by clarify
  1705 
  1706 This technique is potentially adventurous, depending on the facts and
  1707 proof tools being involved here.
  1708 
  1709 * Isar: known facts from the proof context may be specified as literal
  1710 propositions, using ASCII back-quote syntax.  This works wherever
  1711 named facts used to be allowed so far, in proof commands, proof
  1712 methods, attributes etc.  Literal facts are retrieved from the context
  1713 according to unification of type and term parameters.  For example,
  1714 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1715 theorems in the current context, then these are valid literal facts:
  1716 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1717 
  1718 There is also a proof method "fact" which does the same composition
  1719 for explicit goal states, e.g. the following proof texts coincide with
  1720 certain special cases of literal facts:
  1721 
  1722   have "A" by fact                 ==  note `A`
  1723   have "A ==> B" by fact           ==  note `A ==> B`
  1724   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1725   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1726 
  1727 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1728 outer syntax.  Thus symbolic identifiers may be used without
  1729 additional white space in declarations like this: ``assume *: A''.
  1730 
  1731 * Isar: 'print_facts' prints all local facts of the current context,
  1732 both named and unnamed ones.
  1733 
  1734 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1735 
  1736   def x == "t" and y == "u"
  1737 
  1738 * Isar: added command 'unfolding', which is structurally similar to
  1739 'using', but affects both the goal state and facts by unfolding given
  1740 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1741 'unfolded' attribute may be replaced by first-class proof text.
  1742 
  1743 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1744 and command 'unfolding' now all support object-level equalities
  1745 (potentially conditional).  The underlying notion of rewrite rule is
  1746 analogous to the 'rule_format' attribute, but *not* that of the
  1747 Simplifier (which is usually more generous).
  1748 
  1749 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1750 premises of a theorem by n. Useful in conjunction with drule.
  1751 
  1752 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1753 method expression within a sandbox consisting of the first N
  1754 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1755 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1756 simplifies all new goals that emerge from applying rule foo to the
  1757 originally first one.
  1758 
  1759 * Isar: schematic goals are no longer restricted to higher-order
  1760 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1761 expected.
  1762 
  1763 * Isar: the conclusion of a long theorem statement is now either
  1764 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1765 (essentially a disjunction of cases with local parameters and
  1766 assumptions).  The latter allows to express general elimination rules
  1767 adequately; in this notation common elimination rules look like this:
  1768 
  1769   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1770     assumes "EX x. P x"
  1771     obtains x where "P x"
  1772 
  1773   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1774     assumes "A & B"
  1775     obtains A and B
  1776 
  1777   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1778     assumes "A | B"
  1779     obtains
  1780       A
  1781     | B
  1782 
  1783 The subsequent classical rules even refer to the formal "thesis"
  1784 explicitly:
  1785 
  1786   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1787     obtains "~ thesis"
  1788 
  1789   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1790     obtains "thesis ==> something"
  1791 
  1792 The actual proof of an 'obtains' statement is analogous to that of the
  1793 Isar proof element 'obtain', only that there may be several cases.
  1794 Optional case names may be specified in parentheses; these will be
  1795 available both in the present proof and as annotations in the
  1796 resulting rule, for later use with the 'cases' method (cf. attribute
  1797 case_names).
  1798 
  1799 * Isar: the assumptions of a long theorem statement are available as
  1800 "assms" fact in the proof context.  This is more appropriate than the
  1801 (historical) "prems", which refers to all assumptions of the current
  1802 context, including those from the target locale, proof body etc.
  1803 
  1804 * Isar: 'print_statement' prints theorems from the current theory or
  1805 proof context in long statement form, according to the syntax of a
  1806 top-level lemma.
  1807 
  1808 * Isar: 'obtain' takes an optional case name for the local context
  1809 introduction rule (default "that").
  1810 
  1811 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1812 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1813 to occur.
  1814 
  1815 * Pure: syntax "CONST name" produces a fully internalized constant
  1816 according to the current context.  This is particularly useful for
  1817 syntax translations that should refer to internal constant
  1818 representations independently of name spaces.
  1819 
  1820 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1821 instead of "FOO ". This allows multiple binder declarations to coexist
  1822 in the same context.  INCOMPATIBILITY.
  1823 
  1824 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1825 primitive that also works in a locale context (both for constants and
  1826 fixed variables). Type declaration and internal syntactic representation
  1827 of given constants retrieved from the context. Likewise, the
  1828 'no_notation' command allows to remove given syntax annotations from the
  1829 current context.
  1830 
  1831 * Isar/locales: new derived specification elements 'axiomatization',
  1832 'definition', 'abbreviation', which support type-inference, admit
  1833 object-level specifications (equality, equivalence).  See also the
  1834 isar-ref manual.  Examples:
  1835 
  1836   axiomatization
  1837     eq  (infix "===" 50) where
  1838     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1839 
  1840   definition "f x y = x + y + 1"
  1841   definition g where "g x = f x x"
  1842 
  1843   abbreviation
  1844     neq  (infix "=!=" 50) where
  1845     "x =!= y == ~ (x === y)"
  1846 
  1847 These specifications may be also used in a locale context.  Then the
  1848 constants being introduced depend on certain fixed parameters, and the
  1849 constant name is qualified by the locale base name.  An internal
  1850 abbreviation takes care for convenient input and output, making the
  1851 parameters implicit and using the original short name.  See also
  1852 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1853 entities from a monomorphic theory.
  1854 
  1855 Presently, abbreviations are only available 'in' a target locale, but
  1856 not inherited by general import expressions.  Also note that
  1857 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1858 'translations' in common applications.  The "no_abbrevs" print mode
  1859 prevents folding of abbreviations in term output.
  1860 
  1861 Concrete syntax is attached to specified constants in internal form,
  1862 independently of name spaces.  The parse tree representation is
  1863 slightly different -- use 'notation' instead of raw 'syntax', and
  1864 'translations' with explicit "CONST" markup to accommodate this.
  1865 
  1866 * Pure/Isar: unified syntax for new-style specification mechanisms
  1867 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1868 full type inference and dummy patterns ("_").  For example:
  1869 
  1870   definition "K x _ = x"
  1871 
  1872   inductive conj for A B
  1873   where "A ==> B ==> conj A B"
  1874 
  1875 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1876 the current context.  Print mode "no_abbrevs" prevents inversion of
  1877 abbreviations on output.
  1878 
  1879 * Isar/locales: improved parameter handling: use of locales "var" and
  1880 "struct" no longer necessary; - parameter renamings are no longer
  1881 required to be injective.  For example, this allows to define
  1882 endomorphisms as locale endom = homom mult mult h.
  1883 
  1884 * Isar/locales: changed the way locales with predicates are defined.
  1885 Instead of accumulating the specification, the imported expression is
  1886 now an interpretation.  INCOMPATIBILITY: different normal form of
  1887 locale expressions.  In particular, in interpretations of locales with
  1888 predicates, goals repesenting already interpreted fragments are not
  1889 removed automatically.  Use methods `intro_locales' and
  1890 `unfold_locales'; see below.
  1891 
  1892 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1893 provide backward reasoning on locales predicates.  The methods are
  1894 aware of interpretations and discharge corresponding goals.
  1895 `intro_locales' is less aggressive then `unfold_locales' and does not
  1896 unfold predicates to assumptions.
  1897 
  1898 * Isar/locales: the order in which locale fragments are accumulated
  1899 has changed.  This enables to override declarations from fragments due
  1900 to interpretations -- for example, unwanted simp rules.
  1901 
  1902 * Isar/locales: interpretation in theories and proof contexts has been
  1903 extended.  One may now specify (and prove) equations, which are
  1904 unfolded in interpreted theorems.  This is useful for replacing
  1905 defined concepts (constants depending on locale parameters) by
  1906 concepts already existing in the target context.  Example:
  1907 
  1908   interpretation partial_order ["op <= :: [int, int] => bool"]
  1909     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1910 
  1911 Typically, the constant `partial_order.less' is created by a
  1912 definition specification element in the context of locale
  1913 partial_order.
  1914 
  1915 * Method "induct": improved internal context management to support
  1916 local fixes and defines on-the-fly. Thus explicit meta-level
  1917 connectives !!  and ==> are rarely required anymore in inductive goals
  1918 (using object-logic connectives for this purpose has been long
  1919 obsolete anyway). Common proof patterns are explained in
  1920 src/HOL/Induct/Common_Patterns.thy, see also
  1921 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1922 examples.
  1923 
  1924 * Method "induct": improved handling of simultaneous goals. Instead of
  1925 introducing object-level conjunction, the statement is now split into
  1926 several conclusions, while the corresponding symbolic cases are nested
  1927 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1928 see src/HOL/Induct/Common_Patterns.thy, for example.
  1929 
  1930 * Method "induct": mutual induction rules are now specified as a list
  1931 of rule sharing the same induction cases. HOL packages usually provide
  1932 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1933 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1934 mutual induction rules differently, i.e. like this:
  1935 
  1936   (induct rule: foo_bar.inducts)
  1937   (induct set: foo bar)
  1938   (induct pred: foo bar)
  1939   (induct type: foo bar)
  1940 
  1941 The ML function ProjectRule.projections turns old-style rules into the
  1942 new format.
  1943 
  1944 * Method "coinduct": dual of induction, see
  1945 src/HOL/Library/Coinductive_List.thy for various examples.
  1946 
  1947 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1948 considered a legacy feature.
  1949 
  1950 * Attribute "symmetric" produces result with standardized schematic
  1951 variables (index 0).  Potential INCOMPATIBILITY.
  1952 
  1953 * Simplifier: by default the simplifier trace only shows top level
  1954 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1955 default. Thus there is less danger of being flooded by the trace. The
  1956 trace indicates where parts have been suppressed.
  1957   
  1958 * Provers/classical: removed obsolete classical version of elim_format
  1959 attribute; classical elim/dest rules are now treated uniformly when
  1960 manipulating the claset.
  1961 
  1962 * Provers/classical: stricter checks to ensure that supplied intro,
  1963 dest and elim rules are well-formed; dest and elim rules must have at
  1964 least one premise.
  1965 
  1966 * Provers/classical: attributes dest/elim/intro take an optional
  1967 weight argument for the rule (just as the Pure versions).  Weights are
  1968 ignored by automated tools, but determine the search order of single
  1969 rule steps.
  1970 
  1971 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1972 where the body does not mention the bound variable.  Note that dummy
  1973 patterns implicitly depend on their context of bounds, which makes
  1974 "{_. _}" match any set comprehension as expected.  Potential
  1975 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1976 constant "_idtdummy" in the binding position.
  1977 
  1978 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1979 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1980 for example "A -> B" => "Pi A (%_. B)".
  1981 
  1982 * Pure: 'class_deps' command visualizes the subclass relation, using
  1983 the graph browser tool.
  1984 
  1985 * Pure: 'print_theory' now suppresses certain internal declarations by
  1986 default; use '!' option for full details.
  1987 
  1988 
  1989 *** HOL ***
  1990 
  1991 * Method "metis" proves goals by applying the Metis general-purpose
  1992 resolution prover (see also http://gilith.com/software/metis/).
  1993 Examples are in the directory MetisExamples.  WARNING: the
  1994 Isabelle/HOL-Metis integration does not yet work properly with
  1995 multi-threading.
  1996   
  1997 * Command 'sledgehammer' invokes external automatic theorem provers as
  1998 background processes.  It generates calls to the "metis" method if
  1999 successful. These can be pasted into the proof.  Users do not have to
  2000 wait for the automatic provers to return.  WARNING: does not really
  2001 work with multi-threading.
  2002 
  2003 * New "auto_quickcheck" feature tests outermost goal statements for
  2004 potential counter-examples.  Controlled by ML references
  2005 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2006 5000 milliseconds).  Fails silently if statements is outside of
  2007 executable fragment, or any other codgenerator problem occurs.
  2008 
  2009 * New constant "undefined" with axiom "undefined x = undefined".
  2010 
  2011 * Added class "HOL.eq", allowing for code generation with polymorphic
  2012 equality.
  2013 
  2014 * Some renaming of class constants due to canonical name prefixing in
  2015 the new 'class' package:
  2016 
  2017     HOL.abs ~> HOL.abs_class.abs
  2018     HOL.divide ~> HOL.divide_class.divide
  2019     0 ~> HOL.zero_class.zero
  2020     1 ~> HOL.one_class.one
  2021     op + ~> HOL.plus_class.plus
  2022     op - ~> HOL.minus_class.minus
  2023     uminus ~> HOL.minus_class.uminus
  2024     op * ~> HOL.times_class.times
  2025     op < ~> HOL.ord_class.less
  2026     op <= > HOL.ord_class.less_eq
  2027     Nat.power ~> Power.power_class.power
  2028     Nat.size ~> Nat.size_class.size
  2029     Numeral.number_of ~> Numeral.number_class.number_of
  2030     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2031     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2032     Orderings.min ~> Orderings.ord_class.min
  2033     Orderings.max ~> Orderings.ord_class.max
  2034     Divides.op div ~> Divides.div_class.div
  2035     Divides.op mod ~> Divides.div_class.mod
  2036     Divides.op dvd ~> Divides.div_class.dvd
  2037 
  2038 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2039 
  2040 a) User-defined constants using any of the names "plus", "minus",
  2041 "times", "less" or "less_eq". The standard syntax translations for
  2042 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2043 names.
  2044 
  2045 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2046 INCOMPATIBILITY: use more specific names.
  2047 
  2048 c) Permutative equations (e.g. "a + b = b + a")
  2049 Since the change of names also changes the order of terms, permutative
  2050 rewrite rules may get applied in a different order. Experience shows
  2051 that this is rarely the case (only two adaptions in the whole Isabelle
  2052 distribution).  INCOMPATIBILITY: rewrite proofs
  2053 
  2054 d) ML code directly refering to constant names
  2055 This in general only affects hand-written proof tactics, simprocs and
  2056 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2057 Consider using @{const_name} antiquotation.
  2058 
  2059 * New class "default" with associated constant "default".
  2060 
  2061 * Function "sgn" is now overloaded and available on int, real, complex
  2062 (and other numeric types), using class "sgn".  Two possible defs of
  2063 sgn are given as equational assumptions in the classes sgn_if and
  2064 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2065 INCOMPATIBILITY.
  2066 
  2067 * Locale "partial_order" now unified with class "order" (cf. theory
  2068 Orderings), added parameter "less".  INCOMPATIBILITY.
  2069 
  2070 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2071 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2072 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2073 
  2074 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2075 changed order of proof goals in instance proofs.
  2076 
  2077 * The transitivity reasoner for partial and linear orders is set up
  2078 for classes "order" and "linorder".  Instances of the reasoner are available
  2079 in all contexts importing or interpreting the corresponding locales.
  2080 Method "order" invokes the reasoner separately; the reasoner
  2081 is also integrated with the Simplifier as a solver.  Diagnostic
  2082 command 'print_orders' shows the available instances of the reasoner
  2083 in the current context.
  2084 
  2085 * Localized monotonicity predicate in theory "Orderings"; integrated
  2086 lemmas max_of_mono and min_of_mono with this predicate.
  2087 INCOMPATIBILITY.
  2088 
  2089 * Formulation of theorem "dense" changed slightly due to integration
  2090 with new class dense_linear_order.
  2091 
  2092 * Uniform lattice theory development in HOL.
  2093 
  2094     constants "meet" and "join" now named "inf" and "sup"
  2095     constant "Meet" now named "Inf"
  2096 
  2097     classes "meet_semilorder" and "join_semilorder" now named
  2098       "lower_semilattice" and "upper_semilattice"
  2099     class "lorder" now named "lattice"
  2100     class "comp_lat" now named "complete_lattice"
  2101 
  2102     Instantiation of lattice classes allows explicit definitions
  2103     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2104 
  2105   INCOMPATIBILITY.  Theorem renames:
  2106 
  2107     meet_left_le            ~> inf_le1
  2108     meet_right_le           ~> inf_le2
  2109     join_left_le            ~> sup_ge1
  2110     join_right_le           ~> sup_ge2
  2111     meet_join_le            ~> inf_sup_ord
  2112     le_meetI                ~> le_infI
  2113     join_leI                ~> le_supI
  2114     le_meet                 ~> le_inf_iff
  2115     le_join                 ~> ge_sup_conv
  2116     meet_idempotent         ~> inf_idem
  2117     join_idempotent         ~> sup_idem
  2118     meet_comm               ~> inf_commute
  2119     join_comm               ~> sup_commute
  2120     meet_leI1               ~> le_infI1
  2121     meet_leI2               ~> le_infI2
  2122     le_joinI1               ~> le_supI1
  2123     le_joinI2               ~> le_supI2
  2124     meet_assoc              ~> inf_assoc
  2125     join_assoc              ~> sup_assoc
  2126     meet_left_comm          ~> inf_left_commute
  2127     meet_left_idempotent    ~> inf_left_idem
  2128     join_left_comm          ~> sup_left_commute
  2129     join_left_idempotent    ~> sup_left_idem
  2130     meet_aci                ~> inf_aci
  2131     join_aci                ~> sup_aci
  2132     le_def_meet             ~> le_iff_inf
  2133     le_def_join             ~> le_iff_sup
  2134     join_absorp2            ~> sup_absorb2
  2135     join_absorp1            ~> sup_absorb1
  2136     meet_absorp1            ~> inf_absorb1
  2137     meet_absorp2            ~> inf_absorb2
  2138     meet_join_absorp        ~> inf_sup_absorb
  2139     join_meet_absorp        ~> sup_inf_absorb
  2140     distrib_join_le         ~> distrib_sup_le
  2141     distrib_meet_le         ~> distrib_inf_le
  2142 
  2143     add_meet_distrib_left   ~> add_inf_distrib_left
  2144     add_join_distrib_left   ~> add_sup_distrib_left
  2145     is_join_neg_meet        ~> is_join_neg_inf
  2146     is_meet_neg_join        ~> is_meet_neg_sup
  2147     add_meet_distrib_right  ~> add_inf_distrib_right
  2148     add_join_distrib_right  ~> add_sup_distrib_right
  2149     add_meet_join_distribs  ~> add_sup_inf_distribs
  2150     join_eq_neg_meet        ~> sup_eq_neg_inf
  2151     meet_eq_neg_join        ~> inf_eq_neg_sup
  2152     add_eq_meet_join        ~> add_eq_inf_sup
  2153     meet_0_imp_0            ~> inf_0_imp_0
  2154     join_0_imp_0            ~> sup_0_imp_0
  2155     meet_0_eq_0             ~> inf_0_eq_0
  2156     join_0_eq_0             ~> sup_0_eq_0
  2157     neg_meet_eq_join        ~> neg_inf_eq_sup
  2158     neg_join_eq_meet        ~> neg_sup_eq_inf
  2159     join_eq_if              ~> sup_eq_if
  2160 
  2161     mono_meet               ~> mono_inf
  2162     mono_join               ~> mono_sup
  2163     meet_bool_eq            ~> inf_bool_eq
  2164     join_bool_eq            ~> sup_bool_eq
  2165     meet_fun_eq             ~> inf_fun_eq
  2166     join_fun_eq             ~> sup_fun_eq
  2167     meet_set_eq             ~> inf_set_eq
  2168     join_set_eq             ~> sup_set_eq
  2169     meet1_iff               ~> inf1_iff
  2170     meet2_iff               ~> inf2_iff
  2171     meet1I                  ~> inf1I
  2172     meet2I                  ~> inf2I
  2173     meet1D1                 ~> inf1D1
  2174     meet2D1                 ~> inf2D1
  2175     meet1D2                 ~> inf1D2
  2176     meet2D2                 ~> inf2D2
  2177     meet1E                  ~> inf1E
  2178     meet2E                  ~> inf2E
  2179     join1_iff               ~> sup1_iff
  2180     join2_iff               ~> sup2_iff
  2181     join1I1                 ~> sup1I1
  2182     join2I1                 ~> sup2I1
  2183     join1I1                 ~> sup1I1
  2184     join2I2                 ~> sup1I2
  2185     join1CI                 ~> sup1CI
  2186     join2CI                 ~> sup2CI
  2187     join1E                  ~> sup1E
  2188     join2E                  ~> sup2E
  2189 
  2190     is_meet_Meet            ~> is_meet_Inf
  2191     Meet_bool_def           ~> Inf_bool_def
  2192     Meet_fun_def            ~> Inf_fun_def
  2193     Meet_greatest           ~> Inf_greatest
  2194     Meet_lower              ~> Inf_lower
  2195     Meet_set_def            ~> Inf_set_def
  2196 
  2197     Sup_def                 ~> Sup_Inf
  2198     Sup_bool_eq             ~> Sup_bool_def
  2199     Sup_fun_eq              ~> Sup_fun_def
  2200     Sup_set_eq              ~> Sup_set_def
  2201 
  2202     listsp_meetI            ~> listsp_infI
  2203     listsp_meet_eq          ~> listsp_inf_eq
  2204 
  2205     meet_min                ~> inf_min
  2206     join_max                ~> sup_max
  2207 
  2208 * Added syntactic class "size"; overloaded constant "size" now has
  2209 type "'a::size ==> bool"
  2210 
  2211 * Internal reorganisation of `size' of datatypes: size theorems
  2212 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2213 simplification rules by default!); theorems "prod.size" now named
  2214 "*.size".
  2215 
  2216 * Class "div" now inherits from class "times" rather than "type".
  2217 INCOMPATIBILITY.
  2218 
  2219 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2220 Linorder etc.  have disappeared; operations defined in terms of
  2221 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2222 
  2223 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2224 
  2225 * HOL-Word: New extensive library and type for generic, fixed size
  2226 machine words, with arithemtic, bit-wise, shifting and rotating
  2227 operations, reflection into int, nat, and bool lists, automation for
  2228 linear arithmetic (by automatic reflection into nat or int), including
  2229 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2230 arithmetic type classes, supporting automatic simplification of
  2231 numerals on all operations.
  2232 
  2233 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2234 
  2235 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2236 
  2237 * Code generator library theories:
  2238   - Code_Integer represents HOL integers by big integer literals in target
  2239     languages.
  2240   - Code_Char represents HOL characters by character literals in target
  2241     languages.
  2242   - Code_Char_chr like Code_Char, but also offers treatment of character
  2243     codes; includes Code_Integer.
  2244   - Executable_Set allows to generate code for finite sets using lists.
  2245   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2246     denominator).
  2247   - Executable_Real implements a subset of real numbers, namly those
  2248     representable by rational numbers.
  2249   - Efficient_Nat implements natural numbers by integers, which in general will
  2250     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2251     includes Code_Integer.
  2252   - Code_Index provides an additional datatype index which is mapped to
  2253     target-language built-in integers.
  2254   - Code_Message provides an additional datatype message_string which is isomorphic to
  2255     strings; messages are mapped to target-language strings.
  2256 
  2257 * New package for inductive predicates
  2258 
  2259   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2260 
  2261     inductive
  2262       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2263       for z_1 :: U_1 and ... and z_n :: U_m
  2264     where
  2265       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2266     | ...
  2267 
  2268   with full support for type-inference, rather than
  2269 
  2270     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2271 
  2272     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2273     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2274 
  2275     inductive "s z_1 ... z_m"
  2276     intros
  2277       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2278       ...
  2279 
  2280   For backward compatibility, there is a wrapper allowing inductive
  2281   sets to be defined with the new package via
  2282 
  2283     inductive_set
  2284       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2285       for z_1 :: U_1 and ... and z_n :: U_m
  2286     where
  2287       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2288     | ...
  2289 
  2290   or
  2291 
  2292     inductive_set
  2293       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2294       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2295       for z_1 :: U_1 and ... and z_n :: U_m
  2296     where
  2297       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2298     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2299     | ...
  2300 
  2301   if the additional syntax "p ..." is required.
  2302 
  2303   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2304   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2305 
  2306   INCOMPATIBILITIES:
  2307 
  2308   - Since declaration and definition of inductive sets or predicates
  2309     is no longer separated, abbreviations involving the newly
  2310     introduced sets or predicates must be specified together with the
  2311     introduction rules after the 'where' keyword (see above), rather
  2312     than before the actual inductive definition.
  2313 
  2314   - The variables in induction and elimination rules are now
  2315     quantified in the order of their occurrence in the introduction
  2316     rules, rather than in alphabetical order. Since this may break
  2317     some proofs, these proofs either have to be repaired, e.g. by
  2318     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2319     statements of the form
  2320 
  2321       case (rule_i a_i_1 ... a_i_{k_i})
  2322 
  2323     or the old order of quantification has to be restored by explicitly adding
  2324     meta-level quantifiers in the introduction rules, i.e.
  2325 
  2326       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2327 
  2328   - The format of the elimination rules is now
  2329 
  2330       p z_1 ... z_m x_1 ... x_n ==>
  2331         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2332         ==> ... ==> P
  2333 
  2334     for predicates and
  2335 
  2336       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2337         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2338         ==> ... ==> P
  2339 
  2340     for sets rather than
  2341 
  2342       x : s z_1 ... z_m ==>
  2343         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2344         ==> ... ==> P
  2345 
  2346     This may require terms in goals to be expanded to n-tuples
  2347     (e.g. using case_tac or simplification with the split_paired_all
  2348     rule) before the above elimination rule is applicable.
  2349 
  2350   - The elimination or case analysis rules for (mutually) inductive
  2351     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2352     list of rules "p_1_..._p_k.elims" is no longer available.
  2353 
  2354 * New package "function"/"fun" for general recursive functions,
  2355 supporting mutual and nested recursion, definitions in local contexts,
  2356 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2357 for small examples, and the separate tutorial on the function
  2358 package. The old recdef "package" is still available as before, but
  2359 users are encouraged to use the new package.
  2360 
  2361 * Method "lexicographic_order" automatically synthesizes termination
  2362 relations as lexicographic combinations of size measures. 
  2363 
  2364 * Case-expressions allow arbitrary constructor-patterns (including
  2365 "_") and take their order into account, like in functional
  2366 programming.  Internally, this is translated into nested
  2367 case-expressions; missing cases are added and mapped to the predefined
  2368 constant "undefined". In complicated cases printing may no longer show
  2369 the original input but the internal form. Lambda-abstractions allow
  2370 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2371 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2372 variable.
  2373 
  2374 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2375 is an abbreviation for "of_nat :: nat => int". The simplification
  2376 rules for "of_nat" have been changed to work like "int" did
  2377 previously.  Potential INCOMPATIBILITY:
  2378   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2379   - of_nat_diff and of_nat_mult are no longer default simp rules
  2380 
  2381 * Method "algebra" solves polynomial equations over (semi)rings using
  2382 Groebner bases. The (semi)ring structure is defined by locales and the
  2383 tool setup depends on that generic context. Installing the method for
  2384 a specific type involves instantiating the locale and possibly adding
  2385 declarations for computation on the coefficients.  The method is
  2386 already instantiated for natural numbers and for the axiomatic class
  2387 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2388 CALCULEMUS 2007 for the general principles underlying this
  2389 architecture of context-aware proof-tools.
  2390 
  2391 * Method "ferrack" implements quantifier elimination over
  2392 special-purpose dense linear orders using locales (analogous to
  2393 "algebra"). The method is already installed for class
  2394 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2395 rat, etc.
  2396 
  2397 * Former constant "List.op @" now named "List.append".  Use ML
  2398 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2399 circumvent possible incompatibilities when working on ML level.
  2400 
  2401 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2402 
  2403 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2404 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2405 
  2406 * New syntax for Haskell-like list comprehension (input only), eg.
  2407 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2408 
  2409 * The special syntax for function "filter" has changed from [x :
  2410 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2411 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2412 
  2413 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2414 defined on nat only, as an abbreviation for [a..<Suc b]
  2415 INCOMPATIBILITY.
  2416 
  2417 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2418 
  2419 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2420 
  2421 * New lemma collection field_simps (an extension of ring_simps) for
  2422 manipulating (in)equations involving division. Multiplies with all
  2423 denominators that can be proved to be non-zero (in equations) or
  2424 positive/negative (in inequations).
  2425 
  2426 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2427 have been improved and renamed to ring_simps, group_simps and
  2428 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2429 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2430 
  2431 * Theory Library/Commutative_Ring: switched from recdef to function
  2432 package; constants add, mul, pow now curried.  Infix syntax for
  2433 algebraic operations.
  2434 
  2435 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2436 INCOMPATIBILITY.
  2437 
  2438 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2439 INCOMPATIBILITY.
  2440 
  2441 * HOL/records: generalised field-update to take a function on the
  2442 field rather than the new value: r(|A := x|) is translated to A_update
  2443 (K x) r The K-combinator that is internally used is called K_record.
  2444 INCOMPATIBILITY: Usage of the plain update functions has to be
  2445 adapted.
  2446  
  2447 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2448 * x = 0, which are required for a semiring.  Richer structures do not
  2449 inherit from semiring_0 anymore, because this property is a theorem
  2450 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2451 there is more to prove, but this is mostly trivial.
  2452 
  2453 * Class "recpower" is generalized to arbitrary monoids, not just
  2454 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2455 commutativity or semiring properties additionally.
  2456 
  2457 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2458 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2459 better use 'abbreviation'.
  2460 
  2461 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2462 
  2463 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2464 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2465 significant changes for setting up numeral syntax for types:
  2466   - New constants Numeral.pred and Numeral.succ instead
  2467       of former Numeral.bin_pred and Numeral.bin_succ.
  2468   - Use integer operations instead of bin_add, bin_mult and so on.
  2469   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2470   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2471 
  2472 See src/HOL/Integ/IntArith.thy for an example setup.
  2473 
  2474 * Command 'normal_form' computes the normal form of a term that may
  2475 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2476 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2477 heavy-duty computations because the functions are compiled to ML
  2478 first.  Correspondingly, a method "normalization" is provided.  See
  2479 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2480 
  2481 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2482 25 like -->); output depends on the "iff" print_mode, the default is
  2483 "A = B" (with priority 50).
  2484 
  2485 * Relations less (<) and less_eq (<=) are also available on type bool.
  2486 Modified syntax to disallow nesting without explicit parentheses,
  2487 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2488 INCOMPATIBILITY.
  2489 
  2490 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2491 
  2492 * Relation composition operator "op O" now has precedence 75 and binds
  2493 stronger than union and intersection. INCOMPATIBILITY.
  2494 
  2495 * The old set interval syntax "{m..n(}" (and relatives) has been
  2496 removed.  Use "{m..<n}" (and relatives) instead.
  2497 
  2498 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2499 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2500 ``declare [[simproc del: neq]]''.
  2501 
  2502 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2503 True/False.
  2504 
  2505 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2506 
  2507 * Theorem setsum_mult renamed to setsum_right_distrib.
  2508 
  2509 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2510 ``rule'' method.
  2511 
  2512 * Reimplemented methods "sat" and "satx", with several improvements:
  2513 goals no longer need to be stated as "<prems> ==> False", equivalences
  2514 (i.e. "=" on type bool) are handled, variable names of the form
  2515 "lit_<n>" are no longer reserved, significant speedup.
  2516 
  2517 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2518 zChaff is still supported as well.
  2519 
  2520 * 'inductive' and 'datatype': provide projections of mutual rules,
  2521 bundled as foo_bar.inducts;
  2522 
  2523 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2524 Library.
  2525 
  2526 * Library: moved theory Accessible_Part to main HOL.
  2527 
  2528 * Library: added theory Coinductive_List of potentially infinite lists
  2529 as greatest fixed-point.
  2530 
  2531 * Library: added theory AssocList which implements (finite) maps as
  2532 association lists.
  2533 
  2534 * Method "evaluation" solves goals (i.e. a boolean expression)
  2535 efficiently by compiling it to ML.  The goal is "proved" (via an
  2536 oracle) if it evaluates to True.
  2537 
  2538 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2539 also when invoked by the simplifier.  This results in the Simplifier
  2540 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2541 Configuration option fast_arith_split_limit=0 recovers the old
  2542 behavior.
  2543 
  2544 * Support for hex (0x20) and binary (0b1001) numerals.
  2545 
  2546 * New method: reify eqs (t), where eqs are equations for an
  2547 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2548 parameter, computes a term s::'b and a list xs::'a list and proves the
  2549 theorem I xs s = t. This is also known as reification or quoting. The
  2550 resulting theorem is applied to the subgoal to substitute t with I xs
  2551 s.  If t is omitted, the subgoal itself is reified.
  2552 
  2553 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2554 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2555 where f is supposed to be a computable function (in the sense of code
  2556 generattion). The method uses reify to compute s and xs as above then
  2557 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2558 r and finally gets the theorem t = r, which is again applied to the
  2559 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2560 
  2561 * Reflection: Automatic reification now handels binding, an example is
  2562 available in src/HOL/ex/ReflectionEx.thy
  2563 
  2564 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2565 command 'statespace' that is similar to 'record', but introduces an
  2566 abstract specification based on the locale infrastructure instead of
  2567 HOL types.  This leads to extra flexibility in composing state spaces,
  2568 in particular multiple inheritance and renaming of components.
  2569 
  2570 
  2571 *** HOL-Complex ***
  2572 
  2573 * Hyperreal: Functions root and sqrt are now defined on negative real
  2574 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2575 Nonnegativity side conditions have been removed from many lemmas, so
  2576 that more subgoals may now be solved by simplification; potential
  2577 INCOMPATIBILITY.
  2578 
  2579 * Real: new type classes formalize real normed vector spaces and
  2580 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2581 and norm :: 'a => real.
  2582 
  2583 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2584 reals into other types. The overloaded constant Reals :: 'a set is now
  2585 defined as range of_real; potential INCOMPATIBILITY.
  2586 
  2587 * Real: proper support for ML code generation, including 'quickcheck'.
  2588 Reals are implemented as arbitrary precision rationals.
  2589 
  2590 * Hyperreal: Several constants that previously worked only for the
  2591 reals have been generalized, so they now work over arbitrary vector
  2592 spaces. Type annotations may need to be added in some cases; potential
  2593 INCOMPATIBILITY.
  2594 
  2595   Infinitesimal  :: ('a::real_normed_vector) star set
  2596   HFinite        :: ('a::real_normed_vector) star set
  2597   HInfinite      :: ('a::real_normed_vector) star set
  2598   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2599   monad          :: ('a::real_normed_vector) star => 'a star set
  2600   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2601   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2602   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2603   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2604   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2605   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2606   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2607   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2608   sgn            :: 'a::real_normed_vector => 'a
  2609   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2610 
  2611 * Complex: Some complex-specific constants are now abbreviations for
  2612 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2613 hnorm.  Other constants have been entirely removed in favor of the
  2614 polymorphic versions (INCOMPATIBILITY):
  2615 
  2616   approx        <-- capprox
  2617   HFinite       <-- CFinite
  2618   HInfinite     <-- CInfinite
  2619   Infinitesimal <-- CInfinitesimal
  2620   monad         <-- cmonad
  2621   galaxy        <-- cgalaxy
  2622   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2623   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2624   (ns)deriv     <-- (ns)cderiv
  2625 
  2626 
  2627 *** HOL-Algebra ***
  2628 
  2629 * Formalisation of ideals and the quotient construction over rings.
  2630 
  2631 * Order and lattice theory no longer based on records.
  2632 INCOMPATIBILITY.
  2633 
  2634 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2635 greatest_closed.  INCOMPATIBILITY.
  2636 
  2637 * Method algebra is now set up via an attribute.  For examples see
  2638 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2639 of algebraic structures.
  2640 
  2641 * Renamed theory CRing to Ring.
  2642 
  2643 
  2644 *** HOL-Nominal ***
  2645 
  2646 * Substantial, yet incomplete support for nominal datatypes (binding
  2647 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2648 src/HOL/Nominal/Examples.  Prospective users should consult
  2649 http://isabelle.in.tum.de/nominal/
  2650 
  2651 
  2652 *** ML ***
  2653 
  2654 * ML basics: just one true type int, which coincides with IntInf.int
  2655 (even on SML/NJ).
  2656 
  2657 * ML within Isar: antiquotations allow to embed statically-checked
  2658 formal entities in the source, referring to the context available at
  2659 compile-time.  For example:
  2660 
  2661 ML {* @{sort "{zero,one}"} *}
  2662 ML {* @{typ "'a => 'b"} *}
  2663 ML {* @{term "%x. x"} *}
  2664 ML {* @{prop "x == y"} *}
  2665 ML {* @{ctyp "'a => 'b"} *}
  2666 ML {* @{cterm "%x. x"} *}
  2667 ML {* @{cprop "x == y"} *}
  2668 ML {* @{thm asm_rl} *}
  2669 ML {* @{thms asm_rl} *}
  2670 ML {* @{type_name c} *}
  2671 ML {* @{type_syntax c} *}
  2672 ML {* @{const_name c} *}
  2673 ML {* @{const_syntax c} *}
  2674 ML {* @{context} *}
  2675 ML {* @{theory} *}
  2676 ML {* @{theory Pure} *}
  2677 ML {* @{theory_ref} *}
  2678 ML {* @{theory_ref Pure} *}
  2679 ML {* @{simpset} *}
  2680 ML {* @{claset} *}
  2681 ML {* @{clasimpset} *}
  2682 
  2683 The same works for sources being ``used'' within an Isar context.
  2684 
  2685 * ML in Isar: improved error reporting; extra verbosity with
  2686 ML_Context.trace enabled.
  2687 
  2688 * Pure/General/table.ML: the join operations now works via exceptions
  2689 DUP/SAME instead of type option. This is simpler in simple cases, and
  2690 admits slightly more efficient complex applications.
  2691 
  2692 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2693 use Context.generic instead of just theory.
  2694 
  2695 * Pure: datatype Context.generic joins theory/Proof.context and
  2696 provides some facilities for code that works in either kind of
  2697 context, notably GenericDataFun for uniform theory and proof data.
  2698 
  2699 * Pure: simplified internal attribute type, which is now always
  2700 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2701 local (Proof.context) attributes have been discontinued, while
  2702 minimizing code duplication. Thm.rule_attribute and
  2703 Thm.declaration_attribute build canonical attributes; see also structure
  2704 Context for further operations on Context.generic, notably
  2705 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2706 declarations and definitions.
  2707 
  2708 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2709 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2710 init only required for impure data. INCOMPATIBILITY: empty really need
  2711 to be empty (no dependencies on theory content!)
  2712 
  2713 * Pure/kernel: consts certification ignores sort constraints given in
  2714 signature declarations. (This information is not relevant to the
  2715 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2716 potential INCOMPATIBILITY.
  2717 
  2718 * Pure: axiomatic type classes are now purely definitional, with
  2719 explicit proofs of class axioms and super class relations performed
  2720 internally. See Pure/axclass.ML for the main internal interfaces --
  2721 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2722 AxClass.axiomatize_class/classrel/arity supersede
  2723 Sign.add_classes/classrel/arities.
  2724 
  2725 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2726 global/local versions on theory vs. Proof.context have been
  2727 discontinued; Attrib.syntax and Method.syntax have been adapted
  2728 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2729 attributes, methods, etc.
  2730 
  2731 * Pure: several functions of signature "... -> theory -> theory * ..."
  2732 have been reoriented to "... -> theory -> ... * theory" in order to
  2733 allow natural usage in combination with the ||>, ||>>, |-> and
  2734 fold_map combinators.
  2735 
  2736 * Pure: official theorem names (closed derivations) and additional
  2737 comments (tags) are now strictly separate.  Name hints -- which are
  2738 maintained as tags -- may be attached any time without affecting the
  2739 derivation.
  2740 
  2741 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2742 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2743 achieve the old behaviour.
  2744 
  2745 * Pure: the "Goal" constant is now called "prop", supporting a
  2746 slightly more general idea of ``protecting'' meta-level rule
  2747 statements.
  2748 
  2749 * Pure: Logic.(un)varify only works in a global context, which is now
  2750 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2751 Logic.legacy_(un)varify as temporary workaround.
  2752 
  2753 * Pure: structure Name provides scalable operations for generating
  2754 internal variable names, notably Name.variants etc.  This replaces
  2755 some popular functions from term.ML:
  2756 
  2757   Term.variant		->  Name.variant
  2758   Term.variantlist	->  Name.variant_list
  2759   Term.invent_names	->  Name.invent_list
  2760 
  2761 Note that low-level renaming rarely occurs in new code -- operations
  2762 from structure Variable are used instead (see below).
  2763 
  2764 * Pure: structure Variable provides fundamental operations for proper
  2765 treatment of fixed/schematic variables in a context.  For example,
  2766 Variable.import introduces fixes for schematics of given facts and
  2767 Variable.export reverses the effect (up to renaming) -- this replaces
  2768 various freeze_thaw operations.
  2769 
  2770 * Pure: structure Goal provides simple interfaces for
  2771 init/conclude/finish and tactical prove operations (replacing former
  2772 Tactic.prove).  Goal.prove is the canonical way to prove results
  2773 within a given context; Goal.prove_global is a degraded version for
  2774 theory level goals, including a global Drule.standard.  Note that
  2775 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2776 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2777 in a locale context).
  2778 
  2779 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2780 and type checking (Syntax.check_term etc.), with common combinations
  2781 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2782 which are considered legacy and await removal.
  2783 
  2784 * Pure/Syntax: generic interfaces for type unchecking
  2785 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2786 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2787 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2788 available for convenience, but refer to the very same operations using
  2789 a mere theory instead of a full context.
  2790 
  2791 * Isar: simplified treatment of user-level errors, using exception
  2792 ERROR of string uniformly.  Function error now merely raises ERROR,
  2793 without any side effect on output channels.  The Isar toplevel takes
  2794 care of proper display of ERROR exceptions.  ML code may use plain
  2795 handle/can/try; cat_error may be used to concatenate errors like this:
  2796 
  2797   ... handle ERROR msg => cat_error msg "..."
  2798 
  2799 Toplevel ML code (run directly or through the Isar toplevel) may be
  2800 embedded into the Isar toplevel with exception display/debug like
  2801 this:
  2802 
  2803   Isar.toplevel (fn () => ...)
  2804 
  2805 INCOMPATIBILITY, removed special transform_error facilities, removed
  2806 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2807 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2808 -- use plain ERROR instead.
  2809 
  2810 * Isar: theory setup now has type (theory -> theory), instead of a
  2811 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2812 
  2813 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2814 ProofContext.debug/verbose flags.
  2815 
  2816 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2817 theory before entering a proof state.  Transactions now always see a
  2818 quasi-functional intermediate checkpoint, both in interactive and
  2819 batch mode.
  2820 
  2821 * Isar: simplified interfaces for outer syntax.  Renamed
  2822 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2823 OuterSyntax.add_parsers -- this functionality is now included in
  2824 OuterSyntax.command etc.  INCOMPATIBILITY.
  2825 
  2826 * Simplifier: the simpset of a running simplification process now
  2827 contains a proof context (cf. Simplifier.the_context), which is the
  2828 very context that the initial simpset has been retrieved from (by
  2829 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2830 (solver, looper etc.) may depend on arbitrary proof data.
  2831 
  2832 * Simplifier.inherit_context inherits the proof context (plus the
  2833 local bounds) of the current simplification process; any simproc
  2834 etc. that calls the Simplifier recursively should do this!  Removed
  2835 former Simplifier.inherit_bounds, which is already included here --
  2836 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2837 specify an explicit context using Simplifier.context/theory_context.
  2838 
  2839 * Simplifier/Classical Reasoner: more abstract interfaces
  2840 change_simpset/claset for modifying the simpset/claset reference of a
  2841 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2842 INCOMPATIBILITY.
  2843 
  2844 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2845 "Trueprop" etc.
  2846 
  2847 
  2848 *** System ***
  2849 
  2850 * settings: the default heap location within ISABELLE_HOME_USER now
  2851 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2852 Isabelle installations.
  2853 
  2854 * isabelle-process: option -S (secure mode) disables some critical
  2855 operations, notably runtime compilation and evaluation of ML source
  2856 code.
  2857 
  2858 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2859 
  2860 * Support for parallel execution, using native multicore support of
  2861 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2862 independent theories, according to the given theory header
  2863 specifications. The maximum number of worker threads is specified via
  2864 usedir option -M or the "max-threads" setting in Proof General. A
  2865 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2866 to 6 on a 8-core machine.  User-code needs to observe certain
  2867 guidelines for thread-safe programming, see appendix A in the Isar
  2868 Implementation manual.
  2869 
  2870 
  2871 
  2872 New in Isabelle2005 (October 2005)
  2873 ----------------------------------
  2874 
  2875 *** General ***
  2876 
  2877 * Theory headers: the new header syntax for Isar theories is
  2878 
  2879   theory <name>
  2880   imports <theory1> ... <theoryN>
  2881   uses <file1> ... <fileM>
  2882   begin
  2883 
  2884 where the 'uses' part is optional.  The previous syntax
  2885 
  2886   theory <name> = <theory1> + ... + <theoryN>:
  2887 
  2888 will disappear in the next release.  Use isatool fixheaders to convert
  2889 existing theory files.  Note that there is no change in ancient
  2890 non-Isar theories now, but these will disappear soon.
  2891 
  2892 * Theory loader: parent theories can now also be referred to via
  2893 relative and absolute paths.
  2894 
  2895 * Command 'find_theorems' searches for a list of criteria instead of a
  2896 list of constants. Known criteria are: intro, elim, dest, name:string,
  2897 simp:term, and any term. Criteria can be preceded by '-' to select
  2898 theorems that do not match. Intro, elim, dest select theorems that
  2899 match the current goal, name:s selects theorems whose fully qualified
  2900 name contain s, and simp:term selects all simplification rules whose
  2901 lhs match term.  Any other term is interpreted as pattern and selects
  2902 all theorems matching the pattern. Available in ProofGeneral under
  2903 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2904 
  2905   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2906 
  2907 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2908 matching the current goal as introduction rule and not having "HOL."
  2909 in their name (i.e. not being defined in theory HOL).
  2910 
  2911 * Command 'thms_containing' has been discontinued in favour of
  2912 'find_theorems'; INCOMPATIBILITY.
  2913 
  2914 * Communication with Proof General is now 8bit clean, which means that
  2915 Unicode text in UTF-8 encoding may be used within theory texts (both
  2916 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2917 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2918 
  2919   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2920   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2921 
  2922 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2923 Classical Reasoner.  Typical big applications run around 2 times
  2924 faster.
  2925 
  2926 
  2927 *** Document preparation ***
  2928 
  2929 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2930 of raw sources.  Only those symbols that do not require additional
  2931 LaTeX packages (depending on comments in isabellesym.sty) are
  2932 displayed properly, everything else is left verbatim.  isatool display
  2933 and isatool print are used as front ends (these are subject to the
  2934 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2935 
  2936 * Command tags control specific markup of certain regions of text,
  2937 notably folding and hiding.  Predefined tags include "theory" (for
  2938 theory begin and end), "proof" for proof commands, and "ML" for
  2939 commands involving ML code; the additional tags "visible" and
  2940 "invisible" are unused by default.  Users may give explicit tag
  2941 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2942 interpretation of tags is determined by the LaTeX job during document
  2943 preparation: see option -V of isatool usedir, or options -n and -t of
  2944 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2945 \isadroptag.
  2946 
  2947 Several document versions may be produced at the same time via isatool
  2948 usedir (the generated index.html will link all of them).  Typical
  2949 specifications include ''-V document=theory,proof,ML'' to present
  2950 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2951 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2952 these parts without any formal replacement text.  The Isabelle site
  2953 default settings produce ''document'' and ''outline'' versions as
  2954 specified above.
  2955 
  2956 * Several new antiquotations:
  2957 
  2958   @{term_type term} prints a term with its type annotated;
  2959 
  2960   @{typeof term} prints the type of a term;
  2961 
  2962   @{const const} is the same as @{term const}, but checks that the
  2963   argument is a known logical constant;
  2964 
  2965   @{term_style style term} and @{thm_style style thm} print a term or
  2966   theorem applying a "style" to it
  2967 
  2968   @{ML text}
  2969 
  2970 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2971 definitions, equations, inequations etc., 'concl' printing only the
  2972 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2973 to print the specified premise.  TermStyle.add_style provides an ML
  2974 interface for introducing further styles.  See also the "LaTeX Sugar"
  2975 document practical applications.  The ML antiquotation prints
  2976 type-checked ML expressions verbatim.
  2977 
  2978 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2979 and 'text' support optional locale specification '(in loc)', which
  2980 specifies the default context for interpreting antiquotations.  For
  2981 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2982 
  2983 * Option 'locale=NAME' of antiquotations specifies an alternative
  2984 context interpreting the subsequent argument.  For example: @{thm
  2985 [locale=lattice] inf_assoc}.
  2986 
  2987 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2988 a proof context.
  2989 
  2990 * Proper output of antiquotations for theory commands involving a
  2991 proof context (such as 'locale' or 'theorem (in loc) ...').
  2992 
  2993 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2994 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  2995 
  2996 * isatool usedir: new option -C (default true) controls whether option
  2997 -D should include a copy of the original document directory; -C false
  2998 prevents unwanted effects such as copying of administrative CVS data.
  2999 
  3000 
  3001 *** Pure ***
  3002 
  3003 * Considerably improved version of 'constdefs' command.  Now performs
  3004 automatic type-inference of declared constants; additional support for
  3005 local structure declarations (cf. locales and HOL records), see also
  3006 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3007 sequential dependencies of definitions within a single 'constdefs'
  3008 section; moreover, the declared name needs to be an identifier.  If
  3009 all fails, consider to fall back on 'consts' and 'defs' separately.
  3010 
  3011 * Improved indexed syntax and implicit structures.  First of all,
  3012 indexed syntax provides a notational device for subscripted
  3013 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3014 expressions.  Secondly, in a local context with structure
  3015 declarations, number indexes \<^sub>n or the empty index (default
  3016 number 1) refer to a certain fixed variable implicitly; option
  3017 show_structs controls printing of implicit structures.  Typical
  3018 applications of these concepts involve record types and locales.
  3019 
  3020 * New command 'no_syntax' removes grammar declarations (and
  3021 translations) resulting from the given syntax specification, which is
  3022 interpreted in the same manner as for the 'syntax' command.
  3023 
  3024 * 'Advanced' translation functions (parse_translation etc.) may depend
  3025 on the signature of the theory context being presently used for
  3026 parsing/printing, see also isar-ref manual.
  3027 
  3028 * Improved 'oracle' command provides a type-safe interface to turn an
  3029 ML expression of type theory -> T -> term into a primitive rule of
  3030 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3031 is already included here); see also FOL/ex/IffExample.thy;
  3032 INCOMPATIBILITY.
  3033 
  3034 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3035 before); "cI" is no longer bound, use "c.intro" instead.
  3036 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3037 axclasses vs. locales.
  3038 
  3039 * Improved internal renaming of symbolic identifiers -- attach primes
  3040 instead of base 26 numbers.
  3041 
  3042 * New flag show_question_marks controls printing of leading question
  3043 marks in schematic variable names.
  3044 
  3045 * In schematic variable names, *any* symbol following \<^isub> or
  3046 \<^isup> is now treated as part of the base name.  For example, the
  3047 following works without printing of awkward ".0" indexes:
  3048 
  3049   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3050     by simp
  3051 
  3052 * Inner syntax includes (*(*nested*) comments*).
  3053 
  3054 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3055 annotations as "(00...)".
  3056 
  3057 * Clear separation of logical types and nonterminals, where the latter
  3058 may only occur in 'syntax' specifications or type abbreviations.
  3059 Before that distinction was only partially implemented via type class
  3060 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3061 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3062 exotic syntax specifications may require further adaption
  3063 (e.g. Cube/Cube.thy).
  3064 
  3065 * Removed obsolete type class "logic", use the top sort {} instead.
  3066 Note that non-logical types should be declared as 'nonterminals'
  3067 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3068 specifications.
  3069 
  3070 * Attributes 'induct' and 'cases': type or set names may now be
  3071 locally fixed variables as well.
  3072 
  3073 * Simplifier: can now control the depth to which conditional rewriting
  3074 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3075 Limit.
  3076 
  3077 * Simplifier: simplification procedures may now take the current
  3078 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3079 interface), which is very useful for calling the Simplifier
  3080 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3081 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3082 low-level mk_simproc no longer applies Logic.varify internally, to
  3083 allow for use in a context of fixed variables.
  3084 
  3085 * thin_tac now works even if the assumption being deleted contains !!
  3086 or ==>.  More generally, erule now works even if the major premise of
  3087 the elimination rule contains !! or ==>.
  3088 
  3089 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3090 
  3091 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3092 from Pure, which contains all common declarations already.  Both
  3093 theories are defined via plain Isabelle/Isar .thy files.
  3094 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3095 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3096 use isatool fixcpure to adapt your theory and ML sources.
  3097 
  3098 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3099 selections of theorems in named facts via index ranges.
  3100 
  3101 * 'print_theorems': in theory mode, really print the difference
  3102 wrt. the last state (works for interactive theory development only),
  3103 in proof mode print all local facts (cf. 'print_facts');
  3104 
  3105 * 'hide': option '(open)' hides only base names.
  3106 
  3107 * More efficient treatment of intermediate checkpoints in interactive
  3108 theory development.
  3109 
  3110 * Code generator is now invoked via code_module (incremental code
  3111 generation) and code_library (modular code generation, ML structures
  3112 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3113 must be quoted when used as identifiers.
  3114 
  3115 * New 'value' command for reading, evaluating and printing terms using
  3116 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3117 quoted when used as identifier.
  3118 
  3119 
  3120 *** Locales ***
  3121 
  3122 * New commands for the interpretation of locale expressions in
  3123 theories (1), locales (2) and proof contexts (3).  These generate
  3124 proof obligations from the expression specification.  After the
  3125 obligations have been discharged, theorems of the expression are added
  3126 to the theory, target locale or proof context.  The synopsis of the
  3127 commands is a follows:
  3128 
  3129   (1) interpretation expr inst
  3130   (2) interpretation target < expr
  3131   (3) interpret expr inst
  3132 
  3133 Interpretation in theories and proof contexts require a parameter
  3134 instantiation of terms from the current context.  This is applied to
  3135 specifications and theorems of the interpreted expression.
  3136 Interpretation in locales only permits parameter renaming through the
  3137 locale expression.  Interpretation is smart in that interpretations
  3138 that are active already do not occur in proof obligations, neither are
  3139 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3140 inspect active interpretations of a particular locale.  For details,
  3141 see the Isar Reference manual.  Examples can be found in
  3142 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3143 
  3144 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3145 'interpret' instead.
  3146 
  3147 * New context element 'constrains' for adding type constraints to
  3148 parameters.
  3149 
  3150 * Context expressions: renaming of parameters with syntax
  3151 redeclaration.
  3152 
  3153 * Locale declaration: 'includes' disallowed.
  3154 
  3155 * Proper static binding of attribute syntax -- i.e. types / terms /
  3156 facts mentioned as arguments are always those of the locale definition
  3157 context, independently of the context of later invocations.  Moreover,
  3158 locale operations (renaming and type / term instantiation) are applied
  3159 to attribute arguments as expected.
  3160 
  3161 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3162 actual attributes; rare situations may require Attrib.attribute to
  3163 embed those attributes into Attrib.src that lack concrete syntax.
  3164 Attribute implementations need to cooperate properly with the static
  3165 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3166 Attrib.XXX_thm etc. already do the right thing without further
  3167 intervention.  Only unusual applications -- such as "where" or "of"
  3168 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3169 on the context and the facts involved -- may have to assign parsed
  3170 values to argument tokens explicitly.
  3171 
  3172 * Changed parameter management in theorem generation for long goal
  3173 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3174 theorem statement in rare situations.
  3175 
  3176 * Locale inspection command 'print_locale' omits notes elements.  Use
  3177 'print_locale!' to have them included in the output.
  3178 
  3179 
  3180 *** Provers ***
  3181 
  3182 * Provers/hypsubst.ML: improved version of the subst method, for
  3183 single-step rewriting: it now works in bound variable contexts. New is
  3184 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3185 rewrite a different subterm than the original subst method, which is
  3186 still available as 'simplesubst'.
  3187 
  3188 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3189 and quasi orders.
  3190 
  3191 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3192 reflexive-transitive closure of relations.
  3193 
  3194 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3195 limit (previously hard-coded with a value of 20) user-definable.
  3196 
  3197 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3198 is peformed already.  Object-logics merely need to finish their
  3199 initial simpset configuration as before.  INCOMPATIBILITY.
  3200 
  3201 
  3202 *** HOL ***
  3203 
  3204 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3205 
  3206   syntax (epsilon)
  3207     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3208 
  3209 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3210 and x-symbol; use option '-m epsilon' to get it actually printed.
  3211 Moreover, the mathematically important symbolic identifier \<epsilon>
  3212 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3213 
  3214 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3215 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3216 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3217 support corresponding Isar calculations.
  3218 
  3219 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3220 instead of ":".
  3221 
  3222 * theory SetInterval: changed the syntax for open intervals:
  3223 
  3224   Old       New
  3225   {..n(}    {..<n}
  3226   {)n..}    {n<..}
  3227   {m..n(}   {m..<n}
  3228   {)m..n}   {m<..n}
  3229   {)m..n(}  {m<..<n}
  3230 
  3231 The old syntax is still supported but will disappear in the next
  3232 release.  For conversion use the following Emacs search and replace
  3233 patterns (these are not perfect but work quite well):
  3234 
  3235   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3236   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3237 
  3238 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3239 equalities in commutative rings; method 'algebra' provides a generic
  3240 interface.
  3241 
  3242 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3243 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3244 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3245 be a tuple pattern.
  3246 
  3247 Some new syntax forms are available:
  3248 
  3249   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3250   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3251   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3252   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3253 
  3254 The latter form "\<Sum>x < k. e" used to be based on a separate
  3255 function "Summation", which has been discontinued.
  3256 
  3257 * theory Finite_Set: in structured induction proofs, the insert case
  3258 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3259 (insert F x)'.
  3260 
  3261 * The 'refute' command has been extended to support a much larger
  3262 fragment of HOL, including axiomatic type classes, constdefs and
  3263 typedefs, inductive datatypes and recursion.
  3264 
  3265 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3266 Requires zChaff with proof generation to be installed.  See
  3267 HOL/ex/SAT_Examples.thy for examples.
  3268 
  3269 * Datatype induction via method 'induct' now preserves the name of the
  3270 induction variable. For example, when proving P(xs::'a list) by
  3271 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3272 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3273 in unstructured proof scripts.
  3274 
  3275 * Reworked implementation of records.  Improved scalability for
  3276 records with many fields, avoiding performance problems for type
  3277 inference. Records are no longer composed of nested field types, but
  3278 of nested extension types. Therefore the record type only grows linear
  3279 in the number of extensions and not in the number of fields.  The
  3280 top-level (users) view on records is preserved.  Potential
  3281 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3282 old record representation. The type generated for a record is called
  3283 <record_name>_ext_type.
  3284 
  3285 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3286 proofs triggered by a record definition or a simproc (if
  3287 quick_and_dirty is enabled).  Definitions of large records can take
  3288 quite long.
  3289 
  3290 New simproc record_upd_simproc for simplification of multiple record
  3291 updates enabled by default.  Moreover, trivial updates are also
  3292 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3293 occasionally, since simplification is more powerful by default.
  3294 
  3295 * typedef: proper support for polymorphic sets, which contain extra
  3296 type-variables in the term.
  3297 
  3298 * Simplifier: automatically reasons about transitivity chains
  3299 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3300 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3301 old proofs break occasionally as simplification may now solve more
  3302 goals than previously.
  3303 
  3304 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3305 present.  Works for all partial orders (class "order"), in particular
  3306 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3307 just like y <= x.
  3308 
  3309 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3310 bound variable or a constant then the let is unfolded.  Otherwise
  3311 first a is simplified to b, and then f b is simplified to g. If
  3312 possible we abstract b from g arriving at "let x = b in h x",
  3313 otherwise we unfold the let and arrive at g.  The simproc can be
  3314 enabled/disabled by the reference use_let_simproc.  Potential
  3315 INCOMPATIBILITY since simplification is more powerful by default.
  3316 
  3317 * Classical reasoning: the meson method now accepts theorems as arguments.
  3318 
  3319 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3320 jobs to provide advice on the provability of subgoals.
  3321 
  3322 * Theory OrderedGroup and Ring_and_Field: various additions and
  3323 improvements to faciliate calculations involving equalities and
  3324 inequalities.
  3325 
  3326 The following theorems have been eliminated or modified
  3327 (INCOMPATIBILITY):
  3328 
  3329   abs_eq             now named abs_of_nonneg
  3330   abs_of_ge_0        now named abs_of_nonneg
  3331   abs_minus_eq       now named abs_of_nonpos
  3332   imp_abs_id         now named abs_of_nonneg
  3333   imp_abs_neg_id     now named abs_of_nonpos
  3334   mult_pos           now named mult_pos_pos
  3335   mult_pos_le        now named mult_nonneg_nonneg
  3336   mult_pos_neg_le    now named mult_nonneg_nonpos
  3337   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3338   mult_neg           now named mult_neg_neg
  3339   mult_neg_le        now named mult_nonpos_nonpos
  3340 
  3341 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3342      
  3343      zero_le_square
  3344      not_square_less_zero 
  3345 
  3346   The following lemmas have been deleted from Real/RealPow:
  3347   
  3348      realpow_zero_zero
  3349      realpow_two
  3350      realpow_less
  3351      zero_le_power
  3352      realpow_two_le
  3353      abs_realpow_two
  3354      realpow_two_abs     
  3355 
  3356 * Theory Parity: added rules for simplifying exponents.
  3357 
  3358 * Theory List:
  3359 
  3360 The following theorems have been eliminated or modified
  3361 (INCOMPATIBILITY):
  3362 
  3363   list_all_Nil       now named list_all.simps(1)
  3364   list_all_Cons      now named list_all.simps(2)
  3365   list_all_conv      now named list_all_iff
  3366   set_mem_eq         now named mem_iff
  3367 
  3368 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3369 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3370 
  3371 
  3372 *** HOL-Complex ***
  3373 
  3374 * Theory RealDef: better support for embedding natural numbers and
  3375 integers in the reals.
  3376 
  3377 The following theorems have been eliminated or modified
  3378 (INCOMPATIBILITY):
  3379 
  3380   exp_ge_add_one_self  now requires no hypotheses
  3381   real_of_int_add      reversed direction of equality (use [symmetric])
  3382   real_of_int_minus    reversed direction of equality (use [symmetric])
  3383   real_of_int_diff     reversed direction of equality (use [symmetric])
  3384   real_of_int_mult     reversed direction of equality (use [symmetric])
  3385 
  3386 * Theory RComplete: expanded support for floor and ceiling functions.
  3387 
  3388 * Theory Ln is new, with properties of the natural logarithm
  3389 
  3390 * Hyperreal: There is a new type constructor "star" for making
  3391 nonstandard types.  The old type names are now type synonyms:
  3392 
  3393   hypreal = real star
  3394   hypnat = nat star
  3395   hcomplex = complex star
  3396 
  3397 * Hyperreal: Many groups of similarly-defined constants have been
  3398 replaced by polymorphic versions (INCOMPATIBILITY):
  3399 
  3400   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3401 
  3402   starset      <-- starsetNat, starsetC
  3403   *s*          <-- *sNat*, *sc*
  3404   starset_n    <-- starsetNat_n, starsetC_n
  3405   *sn*         <-- *sNatn*, *scn*
  3406   InternalSets <-- InternalNatSets, InternalCSets
  3407 
  3408   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3409   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3410   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3411   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3412   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3413 
  3414 * Hyperreal: Many type-specific theorems have been removed in favor of
  3415 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3416 
  3417   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3418   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3419   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3420   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3421   right_minus <-- hypreal_add_minus
  3422   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3423   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3424   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3425   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3426   mult_1_right <-- hcomplex_mult_one_right
  3427   mult_zero_left <-- hcomplex_mult_zero_left
  3428   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3429   right_distrib <-- hypnat_add_mult_distrib2
  3430   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3431   right_inverse <-- hypreal_mult_inverse
  3432   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3433   order_refl <-- {hypreal,hypnat}_le_refl
  3434   order_trans <-- {hypreal,hypnat}_le_trans
  3435   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3436   order_less_le <-- {hypreal,hypnat}_less_le
  3437   linorder_linear <-- {hypreal,hypnat}_le_linear
  3438   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3439   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3440   add_nonneg_nonneg <-- hypreal_le_add_order
  3441 
  3442 * Hyperreal: Separate theorems having to do with type-specific
  3443 versions of constants have been merged into theorems that apply to the
  3444 new polymorphic constants (INCOMPATIBILITY):
  3445 
  3446   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3447   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3448   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3449   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3450   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3451   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3452   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3453   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3454   STAR_diff <-- {STAR,STARC}_diff
  3455   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3456     STARC_hcomplex_of_complex}_image_subset
  3457   starset_n_Un <-- starset{Nat,C}_n_Un
  3458   starset_n_Int <-- starset{Nat,C}_n_Int
  3459   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3460   starset_n_diff <-- starset{Nat,C}_n_diff
  3461   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3462   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3463   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3464   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3465   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3466   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3467   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3468   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3469   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3470   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3471   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3472   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3473   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3474   starfun_diff <-- starfun{C,RC,CR}_diff
  3475   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3476   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3477   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3478   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3479   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3480   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3481   starfun_Id <-- starfunC_Id
  3482   starfun_approx <-- starfun{Nat,CR}_approx
  3483   starfun_capprox <-- starfun{C,RC}_capprox
  3484   starfun_abs <-- starfunNat_rabs
  3485   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3486   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3487   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3488   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3489   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3490   starfun_add_approx <-- starfunCR_add_approx
  3491   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3492   starfun_divide <-- starfun{C,CR,RC}_divide
  3493   starfun_n <-- starfun{Nat,C}_n
  3494   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3495   starfun_n_add <-- starfun{Nat,C}_n_add
  3496   starfun_n_add_minus <-- starfunNat_n_add_minus
  3497   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3498   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3499   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3500 
  3501   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3502   star_n_minus <-- {hypreal,hcomplex}_minus
  3503   star_n_diff <-- {hypreal,hcomplex}_diff
  3504   star_n_mult <-- {hypreal,hcomplex}_mult
  3505   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3506   star_n_le <-- {hypreal,hypnat}_le
  3507   star_n_less <-- {hypreal,hypnat}_less
  3508   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3509   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3510   star_n_abs <-- hypreal_hrabs
  3511   star_n_divide <-- hcomplex_divide
  3512 
  3513   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3514   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3515   star_of_diff <-- hypreal_of_real_diff
  3516   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3517   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3518   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3519   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3520   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3521   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3522   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3523   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3524   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3525   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3526   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3527   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3528   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3529   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3530   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3531   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3532   star_of_power <-- hypreal_of_real_power
  3533   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3534 
  3535 * Hyperreal: new method "transfer" that implements the transfer
  3536 principle of nonstandard analysis. With a subgoal that mentions
  3537 nonstandard types like "'a star", the command "apply transfer"
  3538 replaces it with an equivalent one that mentions only standard types.
  3539 To be successful, all free variables must have standard types; non-
  3540 standard variables must have explicit universal quantifiers.
  3541 
  3542 * Hyperreal: A theory of Taylor series.
  3543 
  3544 
  3545 *** HOLCF ***
  3546 
  3547 * Discontinued special version of 'constdefs' (which used to support
  3548 continuous functions) in favor of the general Pure one with full
  3549 type-inference.
  3550 
  3551 * New simplification procedure for solving continuity conditions; it
  3552 is much faster on terms with many nested lambda abstractions (cubic
  3553 instead of exponential time).
  3554 
  3555 * New syntax for domain package: selector names are now optional.
  3556 Parentheses should be omitted unless argument is lazy, for example:
  3557 
  3558   domain 'a stream = cons "'a" (lazy "'a stream")
  3559 
  3560 * New command 'fixrec' for defining recursive functions with pattern
  3561 matching; defining multiple functions with mutual recursion is also
  3562 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3563 sinr, or any data constructor defined by the domain package. The given
  3564 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3565 syntax and examples.
  3566 
  3567 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3568 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3569 but the proof obligation additionally includes an admissibility
  3570 requirement. The packages generate instances of class cpo or pcpo,
  3571 with continuity and strictness theorems for Rep and Abs.
  3572 
  3573 * HOLCF: Many theorems have been renamed according to a more standard naming
  3574 scheme (INCOMPATIBILITY):
  3575 
  3576   foo_inject:  "foo$x = foo$y ==> x = y"
  3577   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3578   foo_less:    "(foo$x << foo$y) = (x << y)"
  3579   foo_strict:  "foo$UU = UU"
  3580   foo_defined: "... ==> foo$x ~= UU"
  3581   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3582 
  3583 
  3584 *** ZF ***
  3585 
  3586 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3587 including the First Isomorphism Theorem (on quotienting by the kernel
  3588 of a homomorphism).
  3589 
  3590 * ZF/Simplifier: install second copy of type solver that actually
  3591 makes use of TC rules declared to Isar proof contexts (or locales);
  3592 the old version is still required for ML proof scripts.
  3593 
  3594 
  3595 *** Cube ***
  3596 
  3597 * Converted to Isar theory format; use locales instead of axiomatic
  3598 theories.
  3599 
  3600 
  3601 *** ML ***
  3602 
  3603 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3604 for ||>, ||>>, |>>,
  3605 
  3606 * Pure/library.ML no longer defines its own option datatype, but uses
  3607 that of the SML basis, which has constructors NONE and SOME instead of
  3608 None and Some, as well as exception Option.Option instead of OPTION.
  3609 The functions the, if_none, is_some, is_none have been adapted
  3610 accordingly, while Option.map replaces apsome.
  3611 
  3612 * Pure/library.ML: the exception LIST has been given up in favour of
  3613 the standard exceptions Empty and Subscript, as well as
  3614 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3615 superceded by the standard hd and tl functions etc.
  3616 
  3617 A number of basic list functions are no longer exported to the ML
  3618 toplevel, as they are variants of predefined functions.  The following
  3619 suggests how one can translate existing code:
  3620 
  3621     rev_append xs ys = List.revAppend (xs, ys)
  3622     nth_elem (i, xs) = List.nth (xs, i)
  3623     last_elem xs = List.last xs
  3624     flat xss = List.concat xss
  3625     seq fs = List.app fs
  3626     partition P xs = List.partition P xs
  3627     mapfilter f xs = List.mapPartial f xs
  3628 
  3629 * Pure/library.ML: several combinators for linear functional
  3630 transformations, notably reverse application and composition:
  3631 
  3632   x |> f                f #> g
  3633   (x, y) |-> f          f #-> g
  3634 
  3635 * Pure/library.ML: introduced/changed precedence of infix operators:
  3636 
  3637   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3638   infix 2 ?;
  3639   infix 3 o oo ooo oooo;
  3640   infix 4 ~~ upto downto;
  3641 
  3642 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3643 infix operators.
  3644 
  3645 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3646 fold_map support linear functional transformations and nesting.  For
  3647 example:
  3648 
  3649   fold f [x1, ..., xN] y =
  3650     y |> f x1 |> ... |> f xN
  3651 
  3652   (fold o fold) f [xs1, ..., xsN] y =
  3653     y |> fold f xs1 |> ... |> fold f xsN
  3654 
  3655   fold f [x1, ..., xN] =
  3656     f x1 #> ... #> f xN
  3657 
  3658   (fold o fold) f [xs1, ..., xsN] =
  3659     fold f xs1 #> ... #> fold f xsN
  3660 
  3661 * Pure/library.ML: the following selectors on type 'a option are
  3662 available:
  3663 
  3664   the:               'a option -> 'a  (*partial*)
  3665   these:             'a option -> 'a  where 'a = 'b list
  3666   the_default: 'a -> 'a option -> 'a
  3667   the_list:          'a option -> 'a list
  3668 
  3669 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3670 basic operations for association lists, following natural argument
  3671 order; moreover the explicit equality predicate passed here avoids
  3672 potentially expensive polymorphic runtime equality checks.
  3673 The old functions may be expressed as follows:
  3674 
  3675   assoc = uncurry (AList.lookup (op =))
  3676   assocs = these oo AList.lookup (op =)
  3677   overwrite = uncurry (AList.update (op =)) o swap
  3678 
  3679 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3680 
  3681   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3682   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3683 
  3684 replacing make_keylist and keyfilter (occassionally used)
  3685 Naive rewrites:
  3686 
  3687   make_keylist = AList.make
  3688   keyfilter = AList.find (op =)
  3689 
  3690 * eq_fst and eq_snd now take explicit equality parameter, thus
  3691   avoiding eqtypes. Naive rewrites:
  3692 
  3693     eq_fst = eq_fst (op =)
  3694     eq_snd = eq_snd (op =)
  3695 
  3696 * Removed deprecated apl and apr (rarely used).
  3697   Naive rewrites:
  3698 
  3699     apl (n, op) =>>= curry op n
  3700     apr (op, m) =>>= fn n => op (n, m)
  3701 
  3702 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3703 provides a reasonably efficient light-weight implementation of sets as
  3704 lists.
  3705 
  3706 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3707 few new operations; existing lookup and update are now curried to
  3708 follow natural argument order (for use with fold etc.);
  3709 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3710 
  3711 * Pure/General: output via the Isabelle channels of
  3712 writeln/warning/error etc. is now passed through Output.output, with a
  3713 hook for arbitrary transformations depending on the print_mode
  3714 (cf. Output.add_mode -- the first active mode that provides a output
  3715 function wins).  Already formatted output may be embedded into further
  3716 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3717 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3718 accommodate easy composition of diagnostic messages etc.  Programmers
  3719 rarely need to care about Output.output or Output.raw at all, with
  3720 some notable exceptions: Output.output is required when bypassing the
  3721 standard channels (writeln etc.), or in token translations to produce
  3722 properly formatted results; Output.raw is required when capturing
  3723 already output material that will eventually be presented to the user
  3724 a second time.  For the default print mode, both Output.output and
  3725 Output.raw have no effect.
  3726 
  3727 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3728 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3729 cumulative results are displayed at the end of a batch session.
  3730 
  3731 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3732 replaced by File.platform_path and File.shell_path (with appropriate
  3733 hooks).  This provides a clean interface for unusual systems where the
  3734 internal and external process view of file names are different.
  3735 
  3736 * Pure: more efficient orders for basic syntactic entities: added
  3737 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3738 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3739 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3740 orders now -- potential INCOMPATIBILITY for code that depends on a
  3741 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3742 Library.sort_strings on result).
  3743 
  3744 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3745 fold_types traverse types/terms from left to right, observing natural
  3746 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3747 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3748 
  3749 * Pure: name spaces have been refined, with significant changes of the
  3750 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3751 to extern(_table).  The plain name entry path is superceded by a
  3752 general 'naming' context, which also includes the 'policy' to produce
  3753 a fully qualified name and external accesses of a fully qualified
  3754 name; NameSpace.extend is superceded by context dependent
  3755 Sign.declare_name.  Several theory and proof context operations modify
  3756 the naming context.  Especially note Theory.restore_naming and
  3757 ProofContext.restore_naming to get back to a sane state; note that
  3758 Theory.add_path is no longer sufficient to recover from
  3759 Theory.absolute_path in particular.
  3760 
  3761 * Pure: new flags short_names (default false) and unique_names
  3762 (default true) for controlling output of qualified names.  If
  3763 short_names is set, names are printed unqualified.  If unique_names is
  3764 reset, the name prefix is reduced to the minimum required to achieve
  3765 the original result when interning again, even if there is an overlap
  3766 with earlier declarations.
  3767 
  3768 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3769 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3770 (useful for printing error messages).  INCOMPATIBILITY.
  3771 
  3772 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3773 Theory.theory are now identified, referring to the universal
  3774 Context.theory (see Pure/context.ML).  Actual signature and theory
  3775 content is managed as theory data.  The old code and interfaces were
  3776 spread over many files and structures; the new arrangement introduces
  3777 considerable INCOMPATIBILITY to gain more clarity:
  3778 
  3779   Context -- theory management operations (name, identity, inclusion,
  3780     parents, ancestors, merge, etc.), plus generic theory data;
  3781 
  3782   Sign -- logical signature and syntax operations (declaring consts,
  3783     types, etc.), plus certify/read for common entities;
  3784 
  3785   Theory -- logical theory operations (stating axioms, definitions,
  3786     oracles), plus a copy of logical signature operations (consts,
  3787     types, etc.); also a few basic management operations (Theory.copy,
  3788     Theory.merge, etc.)
  3789 
  3790 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3791 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3792 for convenience -- they merely return the theory.
  3793 
  3794 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3795 
  3796 * Pure: the Isar proof context type is already defined early in Pure
  3797 as Context.proof (note that ProofContext.context and Proof.context are
  3798 aliases, where the latter is the preferred name).  This enables other
  3799 Isabelle components to refer to that type even before Isar is present.
  3800 
  3801 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3802 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3803 any of these kinds.  For example, Sign.intern typeK is now
  3804 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3805 Theory.hide_types.  Also note that former
  3806 Theory.hide_classes/types/consts are now
  3807 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3808 internalize their arguments!  INCOMPATIBILITY.
  3809 
  3810 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3811 datatype thmref (with constructors Name and NameSelection) instead of
  3812 plain string -- INCOMPATIBILITY;
  3813 
  3814 * Pure: cases produced by proof methods specify options, where NONE
  3815 means to remove case bindings -- INCOMPATIBILITY in
  3816 (RAW_)METHOD_CASES.
  3817 
  3818 * Pure: the following operations retrieve axioms or theorems from a
  3819 theory node or theory hierarchy, respectively:
  3820 
  3821   Theory.axioms_of: theory -> (string * term) list
  3822   Theory.all_axioms_of: theory -> (string * term) list
  3823   PureThy.thms_of: theory -> (string * thm) list
  3824   PureThy.all_thms_of: theory -> (string * thm) list
  3825 
  3826 * Pure: print_tac now outputs the goal through the trace channel.
  3827 
  3828 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3829 Reference Toplevel.debug (default false) controls detailed printing
  3830 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3831 controls execution profiling -- set to 1 for time and 2 for space
  3832 (both increase the runtime).
  3833 
  3834 * Isar session: The initial use of ROOT.ML is now always timed,
  3835 i.e. the log will show the actual process times, in contrast to the
  3836 elapsed wall-clock time that the outer shell wrapper produces.
  3837 
  3838 * Simplifier: improved handling of bound variables (nameless
  3839 representation, avoid allocating new strings).  Simprocs that invoke
  3840 the Simplifier recursively should use Simplifier.inherit_bounds to
  3841 avoid local name clashes.  Failure to do so produces warnings
  3842 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3843 for further details.
  3844 
  3845 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3846 bindings for all theorems stored within a given theory; this may help
  3847 in porting non-Isar theories to Isar ones, while keeping ML proof
  3848 scripts for the time being.
  3849 
  3850 * ML operator HTML.with_charset specifies the charset begin used for
  3851 generated HTML files.  For example:
  3852 
  3853   HTML.with_charset "utf-8" use_thy "Hebrew";
  3854   HTML.with_charset "utf-8" use_thy "Chinese";
  3855 
  3856 
  3857 *** System ***
  3858 
  3859 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3860 isabelle, isatool etc.).
  3861 
  3862 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3863 isatool doc, isatool mkdir, display_drafts etc.).
  3864 
  3865 * isatool usedir: option -f allows specification of the ML file to be
  3866 used by Isabelle; default is ROOT.ML.
  3867 
  3868 * New isatool version outputs the version identifier of the Isabelle
  3869 distribution being used.
  3870 
  3871 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3872 (containing Boolean satisfiability problems) into Isabelle/HOL
  3873 theories.
  3874 
  3875 
  3876 
  3877 New in Isabelle2004 (April 2004)
  3878 --------------------------------
  3879 
  3880 *** General ***
  3881 
  3882 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3883   Replaces linorder.ML.
  3884 
  3885 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3886   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3887   (\<a>...\<z>), are now considered normal letters, and can therefore
  3888   be used anywhere where an ASCII letter (a...zA...Z) has until
  3889   now. COMPATIBILITY: This obviously changes the parsing of some
  3890   terms, especially where a symbol has been used as a binder, say
  3891   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3892   as an identifier.  Fix it by inserting a space around former
  3893   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3894   existing theory and ML files.
  3895 
  3896 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3897 
  3898 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3899   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3900   a normal (but invisible) letter. For multiple letter subscripts repeat
  3901   \<^isub> like this: x\<^isub>1\<^isub>2.
  3902 
  3903 * Pure: There are now sub-/superscripts that can span more than one
  3904   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3905   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3906   superscript. The new control characters are not identifier parts.
  3907 
  3908 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3909   content of "..." to the latex file instead of \isacntrl... . The "..."
  3910   may consist of any printable characters excluding the end bracket >.
  3911 
  3912 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3913   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3914   declare constants "final", which prevents their being given a definition
  3915   later.  It is useful for constants whose behaviour is fixed axiomatically
  3916   rather than definitionally, such as the meta-logic connectives.
  3917 
  3918 * Pure: 'instance' now handles general arities with general sorts
  3919   (i.e. intersections of classes),
  3920 
  3921 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3922   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3923   It can be changed to alter the colors/layout of generated pages.
  3924 
  3925 
  3926 *** Isar ***
  3927 
  3928 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3929   cut_tac, subgoal_tac and thin_tac:
  3930   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3931     locales are no longer forced to write Isar proof scripts.
  3932     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3933     emulations.
  3934   - INCOMPATIBILITY: names of variables to be instantiated may no
  3935     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3936     This is consistent with the instantiation attribute "where".
  3937 
  3938 * Attributes "where" and "of":
  3939   - Now take type variables of instantiated theorem into account when reading
  3940     the instantiation string.  This fixes a bug that caused instantiated
  3941     theorems to have too special types in some circumstances.
  3942   - "where" permits explicit instantiations of type variables.
  3943 
  3944 * Calculation commands "moreover" and "also" no longer interfere with
  3945   current facts ("this"), admitting arbitrary combinations with "then"
  3946   and derived forms.
  3947 
  3948 * Locales:
  3949   - Goal statements involving the context element "includes" no longer
  3950     generate theorems with internal delta predicates (those ending on
  3951     "_axioms") in the premise.
  3952     Resolve particular premise with <locale>.intro to obtain old form.
  3953   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3954     specification and "includes" elements in goal statement.
  3955   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3956     [intro?] and [elim?] (respectively) by default.
  3957   - Experimental command for instantiation of locales in proof contexts:
  3958         instantiate <label>[<attrs>]: <loc>
  3959     Instantiates locale <loc> and adds all its theorems to the current context
  3960     taking into account their attributes.  Label and attrs are optional
  3961     modifiers, like in theorem declarations.  If present, names of
  3962     instantiated theorems are qualified with <label>, and the attributes
  3963     <attrs> are applied after any attributes these theorems might have already.
  3964       If the locale has assumptions, a chained fact of the form
  3965     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3966     are derived.  The command does not support old-style locales declared
  3967     with "locale (open)".
  3968       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3969 
  3970 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3971   (Isar) contexts.
  3972 
  3973 
  3974 *** HOL ***
  3975 
  3976 * Proof import: new image HOL4 contains the imported library from
  3977   the HOL4 system with about 2500 theorems. It is imported by
  3978   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3979   can be used like any other Isabelle image.  See
  3980   HOL/Import/HOL/README for more information.
  3981 
  3982 * Simplifier:
  3983   - Much improved handling of linear and partial orders.
  3984     Reasoners for linear and partial orders are set up for type classes
  3985     "linorder" and "order" respectively, and are added to the default simpset
  3986     as solvers.  This means that the simplifier can build transitivity chains
  3987     to solve goals from the assumptions.
  3988   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3989     of blast or auto after simplification become unnecessary because the goal
  3990     is solved by simplification already.
  3991 
  3992 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3993     all proved in axiomatic type classes for semirings, rings and fields.
  3994 
  3995 * Numerics:
  3996   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  3997     now formalized using the Ring_and_Field theory mentioned above.
  3998   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  3999     than before, because now they are set up once in a generic manner.
  4000   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4001     Look for the general versions in Ring_and_Field (and Power if they concern
  4002     exponentiation).
  4003 
  4004 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4005 
  4006 * Records:
  4007   - Record types are now by default printed with their type abbreviation
  4008     instead of the list of all field types. This can be configured via
  4009     the reference "print_record_type_abbr".
  4010   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4011     (not enabled by default).
  4012   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4013     EX x. x = sel r to True (not enabled by default).
  4014   - Tactic "record_split_simp_tac" to split and simplify records added.
  4015 
  4016 * 'specification' command added, allowing for definition by
  4017   specification.  There is also an 'ax_specification' command that
  4018   introduces the new constants axiomatically.
  4019 
  4020 * arith(_tac) is now able to generate counterexamples for reals as well.
  4021 
  4022 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4023 
  4024 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4025   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4026 
  4027 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4028   matrix theory to linear programming.
  4029 
  4030 * Unions and Intersections:
  4031   The latex output syntax of UN and INT has been changed
  4032   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4033   i.e. the index formulae has become a subscript.
  4034   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4035 
  4036 * Unions and Intersections over Intervals:
  4037   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4038   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4039   like in normal math, and corresponding versions for < and for intersection.
  4040 
  4041 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4042   lexicographic dictonary ordering has been added as "lexord".
  4043 
  4044 * ML: the legacy theory structures Int and List have been removed. They had
  4045   conflicted with ML Basis Library structures having the same names.
  4046 
  4047 * 'refute' command added to search for (finite) countermodels.  Only works
  4048   for a fragment of HOL.  The installation of an external SAT solver is
  4049   highly recommended.  See "HOL/Refute.thy" for details.
  4050 
  4051 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4052   formulae under an assignment of free variables to random values.
  4053   In contrast to 'refute', it can deal with inductive datatypes,
  4054   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4055   for examples.
  4056 
  4057 
  4058 *** HOLCF ***
  4059 
  4060 * Streams now come with concatenation and are part of the HOLCF image
  4061 
  4062 
  4063 
  4064 New in Isabelle2003 (May 2003)
  4065 ------------------------------
  4066 
  4067 *** General ***
  4068 
  4069 * Provers/simplifier:
  4070 
  4071   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4072     Assumptions are now subject to complete mutual simplification,
  4073     not just from left to right. The simplifier now preserves
  4074     the order of assumptions.
  4075 
  4076     Potential INCOMPATIBILITY:
  4077 
  4078     -- simp sometimes diverges where the old version did
  4079        not, e.g. invoking simp on the goal
  4080 
  4081         [| P (f x); y = x; f x = f y |] ==> Q
  4082 
  4083        now gives rise to the infinite reduction sequence
  4084 
  4085         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4086 
  4087        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4088        kind of problem.
  4089 
  4090     -- Tactics combining classical reasoner and simplification (such as auto)
  4091        are also affected by this change, because many of them rely on
  4092        simp. They may sometimes diverge as well or yield a different numbers
  4093        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4094        in case of problems. Sometimes subsequent calls to the classical
  4095        reasoner will fail because a preceeding call to the simplifier too
  4096        eagerly simplified the goal, e.g. deleted redundant premises.
  4097 
  4098   - The simplifier trace now shows the names of the applied rewrite rules
  4099 
  4100   - You can limit the number of recursive invocations of the simplifier
  4101     during conditional rewriting (where the simplifie tries to solve the
  4102     conditions before applying the rewrite rule):
  4103     ML "simp_depth_limit := n"
  4104     where n is an integer. Thus you can force termination where previously
  4105     the simplifier would diverge.
  4106 
  4107   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4108 
  4109   - No longer aborts on failed congruence proof.  Instead, the
  4110     congruence is ignored.
  4111 
  4112 * Pure: New generic framework for extracting programs from constructive
  4113   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4114   as HOL/Extraction for some case studies.
  4115 
  4116 * Pure: The main goal of the proof state is no longer shown by default, only
  4117 the subgoals. This behaviour is controlled by a new flag.
  4118    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4119 (ML: Proof.show_main_goal).
  4120 
  4121 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4122 rules whose conclusion matches subgoal 1:
  4123       PG menu: Isabelle/Isar -> Show me -> matching rules
  4124 The rules are ordered by how closely they match the subgoal.
  4125 In particular, rules that solve a subgoal outright are displayed first
  4126 (or rather last, the way they are printed).
  4127 (ML: ProofGeneral.print_intros())
  4128 
  4129 * Pure: New flag trace_unify_fail causes unification to print
  4130 diagnostic information (PG: in trace buffer) when it fails. This is
  4131 useful for figuring out why single step proofs like rule, erule or
  4132 assumption failed.
  4133 
  4134 * Pure: Locale specifications now produce predicate definitions
  4135 according to the body of text (covering assumptions modulo local
  4136 definitions); predicate "loc_axioms" covers newly introduced text,
  4137 while "loc" is cumulative wrt. all included locale expressions; the
  4138 latter view is presented only on export into the global theory
  4139 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4140 on the old view without predicates;
  4141 
  4142 * Pure: predefined locales "var" and "struct" are useful for sharing
  4143 parameters (as in CASL, for example); just specify something like
  4144 ``var x + var y + struct M'' as import;
  4145 
  4146 * Pure: improved thms_containing: proper indexing of facts instead of
  4147 raw theorems; check validity of results wrt. current name space;
  4148 include local facts of proof configuration (also covers active
  4149 locales), cover fixed variables in index; may use "_" in term
  4150 specification; an optional limit for the number of printed facts may
  4151 be given (the default is 40);
  4152 
  4153 * Pure: disallow duplicate fact bindings within new-style theory files
  4154 (batch-mode only);
  4155 
  4156 * Provers: improved induct method: assumptions introduced by case
  4157 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4158 the goal statement); "foo" still refers to all facts collectively;
  4159 
  4160 * Provers: the function blast.overloaded has been removed: all constants
  4161 are regarded as potentially overloaded, which improves robustness in exchange
  4162 for slight decrease in efficiency;
  4163 
  4164 * Provers/linorder: New generic prover for transitivity reasoning over
  4165 linear orders.  Note: this prover is not efficient!
  4166 
  4167 * Isar: preview of problems to finish 'show' now produce an error
  4168 rather than just a warning (in interactive mode);
  4169 
  4170 
  4171 *** HOL ***
  4172 
  4173 * arith(_tac)
  4174 
  4175  - Produces a counter example if it cannot prove a goal.
  4176    Note that the counter example may be spurious if the goal is not a formula
  4177    of quantifier-free linear arithmetic.
  4178    In ProofGeneral the counter example appears in the trace buffer.
  4179 
  4180  - Knows about div k and mod k where k is a numeral of type nat or int.
  4181 
  4182  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4183    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4184    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4185 
  4186 * simp's arithmetic capabilities have been enhanced a bit: it now
  4187 takes ~= in premises into account (by performing a case split);
  4188 
  4189 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4190 are distributed over a sum of terms;
  4191 
  4192 * New tactic "trans_tac" and method "trans" instantiate
  4193 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4194 "<=", "<" and "=").
  4195 
  4196 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4197 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4198 
  4199 * 'typedef' command has new option "open" to suppress the set
  4200 definition;
  4201 
  4202 * functions Min and Max on finite sets have been introduced (theory
  4203 Finite_Set);
  4204 
  4205 * attribute [symmetric] now works for relations as well; it turns
  4206 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4207 
  4208 * induct over a !!-quantified statement (say !!x1..xn):
  4209   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4210 
  4211 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4212 %x. None. Warning: empty_def now refers to the previously hidden definition
  4213 of the empty set.
  4214 
  4215 * Algebra: formalization of classical algebra.  Intended as base for
  4216 any algebraic development in Isabelle.  Currently covers group theory
  4217 (up to Sylow's theorem) and ring theory (Universal Property of
  4218 Univariate Polynomials).  Contributions welcome;
  4219 
  4220 * GroupTheory: deleted, since its material has been moved to Algebra;
  4221 
  4222 * Complex: new directory of the complex numbers with numeric constants,
  4223 nonstandard complex numbers, and some complex analysis, standard and
  4224 nonstandard (Jacques Fleuriot);
  4225 
  4226 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4227 
  4228 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4229 Fleuriot);
  4230 
  4231 * Real/HahnBanach: updated and adapted to locales;
  4232 
  4233 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4234 Gray and Kramer);
  4235 
  4236 * UNITY: added the Meier-Sanders theory of progress sets;
  4237 
  4238 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4239 as abstract algorithms, instantiated to the JVM;
  4240 
  4241 * Bali: Java source language formalization. Type system, operational
  4242 semantics, axiomatic semantics. Supported language features:
  4243 classes, interfaces, objects,virtual methods, static methods,
  4244 static/instance fields, arrays, access modifiers, definite
  4245 assignment, exceptions.
  4246 
  4247 
  4248 *** ZF ***
  4249 
  4250 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4251 universe, etc.);
  4252 
  4253 * Main ZF: virtually all theories converted to new-style format;
  4254 
  4255 
  4256 *** ML ***
  4257 
  4258 * Pure: Tactic.prove provides sane interface for internal proofs;
  4259 omits the infamous "standard" operation, so this is more appropriate
  4260 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4261 
  4262 * Pure: improved error reporting of simprocs;
  4263 
  4264 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4265 up simprocs;
  4266 
  4267 
  4268 *** Document preparation ***
  4269 
  4270 * uses \par instead of \\ for line breaks in theory text. This may
  4271 shift some page breaks in large documents. To get the old behaviour
  4272 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4273 
  4274 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4275 other packages
  4276 
  4277 * \<euro> now needs package babel/greek instead of marvosym (which
  4278 broke \Rightarrow)
  4279 
  4280 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4281 textcomp package)
  4282 
  4283 
  4284 
  4285 New in Isabelle2002 (March 2002)
  4286 --------------------------------
  4287 
  4288 *** Document preparation ***
  4289 
  4290 * greatly simplified document preparation setup, including more
  4291 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4292 instructive isatool mkdir; users should basically be able to get
  4293 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4294 users may run a separate document processing stage manually like this:
  4295 "isatool usedir -D output HOL Test && isatool document Test/output";
  4296 
  4297 * theory dependency graph may now be incorporated into documents;
  4298 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4299 with \includegraphics of LaTeX;
  4300 
  4301 * proper spacing of consecutive markup elements, especially text
  4302 blocks after section headings;
  4303 
  4304 * support bold style (for single symbols only), input syntax is like
  4305 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4306 
  4307 * \<bullet> is now output as bold \cdot by default, which looks much
  4308 better in printed text;
  4309 
  4310 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4311 note that these symbols are currently unavailable in Proof General /
  4312 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4313 
  4314 * isatool latex no longer depends on changed TEXINPUTS, instead
  4315 isatool document copies the Isabelle style files to the target
  4316 location;
  4317 
  4318 
  4319 *** Isar ***
  4320 
  4321 * Pure/Provers: improved proof by cases and induction;
  4322   - 'case' command admits impromptu naming of parameters (such as
  4323     "case (Suc n)");
  4324   - 'induct' method divinates rule instantiation from the inductive
  4325     claim; no longer requires excessive ?P bindings for proper
  4326     instantiation of cases;
  4327   - 'induct' method properly enumerates all possibilities of set/type
  4328     rules; as a consequence facts may be also passed through *type*
  4329     rules without further ado;
  4330   - 'induct' method now derives symbolic cases from the *rulified*
  4331     rule (before it used to rulify cases stemming from the internal
  4332     atomized version); this means that the context of a non-atomic
  4333     statement becomes is included in the hypothesis, avoiding the
  4334     slightly cumbersome show "PROP ?case" form;
  4335   - 'induct' may now use elim-style induction rules without chaining
  4336     facts, using ``missing'' premises from the goal state; this allows
  4337     rules stemming from inductive sets to be applied in unstructured
  4338     scripts, while still benefitting from proper handling of non-atomic
  4339     statements; NB: major inductive premises need to be put first, all
  4340     the rest of the goal is passed through the induction;
  4341   - 'induct' proper support for mutual induction involving non-atomic
  4342     rule statements (uses the new concept of simultaneous goals, see
  4343     below);
  4344   - append all possible rule selections, but only use the first
  4345     success (no backtracking);
  4346   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4347   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4348   - added 'print_induct_rules' (covered by help item in recent Proof
  4349     General versions);
  4350   - moved induct/cases attributes to Pure, methods to Provers;
  4351   - generic method setup instantiated for FOL and HOL;
  4352 
  4353 * Pure: support multiple simultaneous goal statements, for example
  4354 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4355 meta-level mechanism, this acts as if several individual goals had
  4356 been stated separately; in particular common proof methods need to be
  4357 repeated in order to cover all claims; note that a single elimination
  4358 step is *not* sufficient to establish the two conjunctions, so this
  4359 fails:
  4360 
  4361   assume "A & B" then have A and B ..   (*".." fails*)
  4362 
  4363 better use "obtain" in situations as above; alternative refer to
  4364 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4365 
  4366 * Pure: proper integration with ``locales''; unlike the original
  4367 version by Florian Kammller, Isar locales package high-level proof
  4368 contexts rather than raw logical ones (e.g. we admit to include
  4369 attributes everywhere); operations on locales include merge and
  4370 rename; support for implicit arguments (``structures''); simultaneous
  4371 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4372 some examples;
  4373 
  4374 * Pure: the following commands have been ``localized'', supporting a
  4375 target locale specification "(in name)": 'lemma', 'theorem',
  4376 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4377 stored both within the locale and at the theory level (exported and
  4378 qualified by the locale name);
  4379 
  4380 * Pure: theory goals may now be specified in ``long'' form, with
  4381 ad-hoc contexts consisting of arbitrary locale elements. for example
  4382 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4383 definitions may be given, too); the result is a meta-level rule with
  4384 the context elements being discharged in the obvious way;
  4385 
  4386 * Pure: new proof command 'using' allows to augment currently used
  4387 facts after a goal statement ('using' is syntactically analogous to
  4388 'apply', but acts on the goal's facts only); this allows chained facts
  4389 to be separated into parts given before and after a claim, as in
  4390 ``from a and b have C using d and e <proof>'';
  4391 
  4392 * Pure: renamed "antecedent" case to "rule_context";
  4393 
  4394 * Pure: new 'judgment' command records explicit information about the
  4395 object-logic embedding (used by several tools internally); no longer
  4396 use hard-wired "Trueprop";
  4397 
  4398 * Pure: added 'corollary' command;
  4399 
  4400 * Pure: fixed 'token_translation' command;
  4401 
  4402 * Pure: removed obsolete 'exported' attribute;
  4403 
  4404 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4405 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4406 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4407 
  4408 * Pure: method 'atomize' presents local goal premises as object-level
  4409 statements (atomic meta-level propositions); setup controlled via
  4410 rewrite rules declarations of 'atomize' attribute; example
  4411 application: 'induct' method with proper rule statements in improper
  4412 proof *scripts*;
  4413 
  4414 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4415 now consider the syntactic context of assumptions, giving a better
  4416 chance to get type-inference of the arguments right (this is
  4417 especially important for locales);
  4418 
  4419 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4420 mode;
  4421 
  4422 * Pure/obtain: the formal conclusion "thesis", being marked as
  4423 ``internal'', may no longer be reference directly in the text;
  4424 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4425 situations;
  4426 
  4427 * Pure: generic 'sym' attribute which declares a rule both as pure
  4428 'elim?' and for the 'symmetric' operation;
  4429 
  4430 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4431 text; the fixed correlation with particular command syntax has been
  4432 discontinued;
  4433 
  4434 * Pure: new method 'rules' is particularly well-suited for proof
  4435 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4436 but often produces more compact proof terms with less detours;
  4437 
  4438 * Pure/Provers/classical: simplified integration with pure rule
  4439 attributes and methods; the classical "intro?/elim?/dest?"
  4440 declarations coincide with the pure ones; the "rule" method no longer
  4441 includes classically swapped intros; "intro" and "elim" methods no
  4442 longer pick rules from the context; also got rid of ML declarations
  4443 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4444 INCOMPATIBILITY;
  4445 
  4446 * Provers/classical: attribute 'swapped' produces classical inversions
  4447 of introduction rules;
  4448 
  4449 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4450 rules instead of full simplifier context; 'iff' attribute handles
  4451 conditional rules;
  4452 
  4453 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4454 
  4455 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4456 "(permissive)" option to recover old behavior;
  4457 
  4458 * HOL: 'inductive' no longer features separate (collective) attributes
  4459 for 'intros' (was found too confusing);
  4460 
  4461 * HOL: properly declared induction rules less_induct and
  4462 wf_induct_rule;
  4463 
  4464 
  4465 *** HOL ***
  4466 
  4467 * HOL: moved over to sane numeral syntax; the new policy is as
  4468 follows:
  4469 
  4470   - 0 and 1 are polymorphic constants, which are defined on any
  4471   numeric type (nat, int, real etc.);
  4472 
  4473   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4474   binary representation internally;
  4475 
  4476   - type nat has special constructor Suc, and generally prefers Suc 0
  4477   over 1::nat and Suc (Suc 0) over 2::nat;
  4478 
  4479 This change may cause significant problems of INCOMPATIBILITY; here
  4480 are some hints on converting existing sources:
  4481 
  4482   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4483   entities, so expressions involving "-" (unary or binary minus) need
  4484   to be spaced properly;
  4485 
  4486   - existing occurrences of "1" may need to be constraint "1::nat" or
  4487   even replaced by Suc 0; similar for old "2";
  4488 
  4489   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4490 
  4491   - remove all special provisions on numerals in proofs;
  4492 
  4493 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4494 representation (depends on bin_arith_simps in the default context);
  4495 
  4496 * HOL: symbolic syntax for x^2 (numeral 2);
  4497 
  4498 * HOL: the class of all HOL types is now called "type" rather than
  4499 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4500 in axclass/classes, instance/arities, and (usually rare) occurrences
  4501 in typings (of consts etc.); internally the class is called
  4502 "HOL.type", ML programs should refer to HOLogic.typeS;
  4503 
  4504 * HOL/record package improvements:
  4505   - new derived operations "fields" to build a partial record section,
  4506     "extend" to promote a fixed record to a record scheme, and
  4507     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4508     declared as simp by default;
  4509   - shared operations ("more", "fields", etc.) now need to be always
  4510     qualified) --- potential INCOMPATIBILITY;
  4511   - removed "make_scheme" operations (use "make" with "extend") --
  4512     INCOMPATIBILITY;
  4513   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4514   - provides cases/induct rules for use with corresponding Isar
  4515     methods (for concrete records, record schemes, concrete more
  4516     parts, and schematic more parts -- in that order);
  4517   - internal definitions directly based on a light-weight abstract
  4518     theory of product types over typedef rather than datatype;
  4519 
  4520 * HOL: generic code generator for generating executable ML code from
  4521 specifications; specific support for HOL constructs such as inductive
  4522 datatypes and sets, as well as recursive functions; can be invoked
  4523 via 'generate_code' theory section;
  4524 
  4525 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4526 
  4527 * HOL: consolidated and renamed several theories.  In particular:
  4528         Ord.thy has been absorbed into HOL.thy
  4529         String.thy has been absorbed into List.thy
  4530 
  4531 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4532 (beware of argument permutation!);
  4533 
  4534 * HOL: linorder_less_split superseded by linorder_cases;
  4535 
  4536 * HOL/List: "nodups" renamed to "distinct";
  4537 
  4538 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4539 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4540   - Ex_def has changed, now need to use some_eq_ex
  4541 
  4542 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4543 in this (rare) case use:
  4544 
  4545   delSWrapper "split_all_tac"
  4546   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4547 
  4548 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4549 MAY FAIL;
  4550 
  4551 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4552 Isabelle's type classes, ^ on functions and relations has too general
  4553 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4554 necessary to attach explicit type constraints;
  4555 
  4556 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4557 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4558 renamed accordingly (eg "compI" -> "rel_compI").
  4559 
  4560 * HOL: syntax translations now work properly with numerals and records
  4561 expressions;
  4562 
  4563 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4564 of "lam" -- INCOMPATIBILITY;
  4565 
  4566 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4567 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4568 renamed "Product_Type.unit";
  4569 
  4570 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4571 
  4572 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4573 the "cases" method);
  4574 
  4575 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4576 Florian Kammller);
  4577 
  4578 * HOL/IMP: updated and converted to new-style theory format; several
  4579 parts turned into readable document, with proper Isar proof texts and
  4580 some explanations (by Gerwin Klein);
  4581 
  4582 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4583 
  4584 * HOL-Hyperreal is now a logic image;
  4585 
  4586 
  4587 *** HOLCF ***
  4588 
  4589 * Isar: consts/constdefs supports mixfix syntax for continuous
  4590 operations;
  4591 
  4592 * Isar: domain package adapted to new-style theory format, e.g. see
  4593 HOLCF/ex/Dnat.thy;
  4594 
  4595 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4596 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4597 lift.induct_tac, always use UU instead of Undef;
  4598 
  4599 * HOLCF/IMP: updated and converted to new-style theory;
  4600 
  4601 
  4602 *** ZF ***
  4603 
  4604 * Isar: proper integration of logic-specific tools and packages,
  4605 including theory commands '(co)inductive', '(co)datatype',
  4606 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4607 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4608 
  4609 * theory Main no longer includes AC; for the Axiom of Choice, base
  4610 your theory on Main_ZFC;
  4611 
  4612 * the integer library now covers quotients and remainders, with many
  4613 laws relating division to addition, multiplication, etc.;
  4614 
  4615 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4616 typeless version of the formalism;
  4617 
  4618 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4619 format;
  4620 
  4621 * ZF/Induct: new directory for examples of inductive definitions,
  4622 including theory Multiset for multiset orderings; converted to
  4623 new-style theory format;
  4624 
  4625 * ZF: many new theorems about lists, ordinals, etc.;
  4626 
  4627 
  4628 *** General ***
  4629 
  4630 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4631 variable proof controls level of detail: 0 = no proofs (only oracle
  4632 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4633 also ref manual for further ML interfaces;
  4634 
  4635 * Pure/axclass: removed obsolete ML interface
  4636 goal_subclass/goal_arity;
  4637 
  4638 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4639 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4640 separate tokens, so expressions involving minus need to be spaced
  4641 properly;
  4642 
  4643 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4644 rather than "infixl" or "infixr";
  4645 
  4646 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4647 sort constraint specifications in type inference; e.g. "x::_::foo"
  4648 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4649 type variable);
  4650 
  4651 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4652 control output of nested => (types); the default behavior is
  4653 "type_brackets";
  4654 
  4655 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4656 tokens into AST constants;
  4657 
  4658 * Pure/syntax: prefer later declarations of translations and print
  4659 translation functions; potential INCOMPATIBILITY: need to reverse
  4660 multiple declarations for same syntax element constant;
  4661 
  4662 * Pure/show_hyps reset by default (in accordance to existing Isar
  4663 practice);
  4664 
  4665 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4666 addSafter;
  4667 
  4668 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4669 as well;
  4670 
  4671 * system: tested support for MacOS X; should be able to get Isabelle +
  4672 Proof General to work in a plain Terminal after installing Poly/ML
  4673 (e.g. from the Isabelle distribution area) and GNU bash alone
  4674 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4675 support requires further installations, e.g. from
  4676 http://fink.sourceforge.net/);
  4677 
  4678 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4679 
  4680 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4681 of 40 MB), cf. ML_OPTIONS;
  4682 
  4683 * system: Proof General keywords specification is now part of the
  4684 Isabelle distribution (see etc/isar-keywords.el);
  4685 
  4686 * system: support for persistent Proof General sessions (refrain from
  4687 outdating all loaded theories on startup); user may create writable
  4688 logic images like this: ``isabelle -q HOL Test'';
  4689 
  4690 * system: smart selection of Isabelle process versus Isabelle
  4691 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4692 run both "isabelle" and "Isabelle" even if file names are badly
  4693 damaged (executable inspects the case of the first letter of its own
  4694 name); added separate "isabelle-process" and "isabelle-interface";
  4695 
  4696 * system: refrain from any attempt at filtering input streams; no
  4697 longer support ``8bit'' encoding of old isabelle font, instead proper
  4698 iso-latin characters may now be used; the related isatools
  4699 "symbolinput" and "nonascii" have disappeared as well;
  4700 
  4701 * system: removed old "xterm" interface (the print modes "xterm" and
  4702 "xterm_color" are still available for direct use in a suitable
  4703 terminal);
  4704 
  4705 
  4706 
  4707 New in Isabelle99-2 (February 2001)
  4708 -----------------------------------
  4709 
  4710 *** Overview of INCOMPATIBILITIES ***
  4711 
  4712 * HOL: please note that theories in the Library and elsewhere often use the
  4713 new-style (Isar) format; to refer to their theorems in an ML script you must
  4714 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4715 
  4716 * HOL: inductive package no longer splits induction rule aggressively,
  4717 but only as far as specified by the introductions given; the old
  4718 format may be recovered via ML function complete_split_rule or attribute
  4719 'split_rule (complete)';
  4720 
  4721 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4722 gfp_Tarski to gfp_unfold;
  4723 
  4724 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4725 
  4726 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4727 relation); infix "^^" has been renamed "``"; infix "``" has been
  4728 renamed "`"; "univalent" has been renamed "single_valued";
  4729 
  4730 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4731 operation;
  4732 
  4733 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4734 
  4735 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4736 
  4737 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4738 consequence, it is no longer monotonic wrt. the local goal context
  4739 (which is now passed through the inductive cases);
  4740 
  4741 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4742 \<gg> to \<ggreater>;
  4743 
  4744 
  4745 *** Document preparation ***
  4746 
  4747 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4748 available: are "it" for near math-mode best-style output, "sl" for
  4749 slanted text style, and "tt" for plain type-writer; if no
  4750 \isabellestyle command is given, output is according to slanted
  4751 type-writer);
  4752 
  4753 * support sub/super scripts (for single symbols only), input syntax is
  4754 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4755 
  4756 * some more standard symbols; see Appendix A of the system manual for
  4757 the complete list of symbols defined in isabellesym.sty;
  4758 
  4759 * improved isabelle style files; more abstract symbol implementation
  4760 (should now use \isamath{...} and \isatext{...} in custom symbol
  4761 definitions);
  4762 
  4763 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4764 state; Note that presentation of goal states does not conform to
  4765 actual human-readable proof documents.  Please do not include goal
  4766 states into document output unless you really know what you are doing!
  4767 
  4768 * proper indentation of antiquoted output with proportional LaTeX
  4769 fonts;
  4770 
  4771 * no_document ML operator temporarily disables LaTeX document
  4772 generation;
  4773 
  4774 * isatool unsymbolize tunes sources for plain ASCII communication;
  4775 
  4776 
  4777 *** Isar ***
  4778 
  4779 * Pure: Isar now suffers initial goal statements to contain unbound
  4780 schematic variables (this does not conform to actual readable proof
  4781 documents, due to unpredictable outcome and non-compositional proof
  4782 checking); users who know what they are doing may use schematic goals
  4783 for Prolog-style synthesis of proven results;
  4784 
  4785 * Pure: assumption method (an implicit finishing) now handles actual
  4786 rules as well;
  4787 
  4788 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4789 initial goal, declare "that" only as Pure intro (only for single
  4790 steps); the "that" rule assumption may now be involved in implicit
  4791 finishing, thus ".." becomes a feasible for trivial obtains;
  4792 
  4793 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4794 instance proofs may be performed by "..";
  4795 
  4796 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4797 statements as well;
  4798 
  4799 * Pure: more robust selection of calculational rules;
  4800 
  4801 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4802 rule (as well as the assumption rule);
  4803 
  4804 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4805 lemmas, using the graph browser tool;
  4806 
  4807 * Pure: predict failure of "show" in interactive mode;
  4808 
  4809 * Pure: 'thms_containing' now takes actual terms as arguments;
  4810 
  4811 * HOL: improved method 'induct' --- now handles non-atomic goals
  4812 (potential INCOMPATIBILITY); tuned error handling;
  4813 
  4814 * HOL: cases and induct rules now provide explicit hints about the
  4815 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4816 any remaining facts are inserted into the goal verbatim;
  4817 
  4818 * HOL: local contexts (aka cases) may now contain term bindings as
  4819 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4820 the result to be shown in each case;
  4821 
  4822 * HOL: added 'recdef_tc' command;
  4823 
  4824 * isatool convert assists in eliminating legacy ML scripts;
  4825 
  4826 
  4827 *** HOL ***
  4828 
  4829 * HOL/Library: a collection of generic theories to be used together
  4830 with main HOL; the theory loader path already includes this directory
  4831 by default; the following existing theories have been moved here:
  4832 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4833 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4834 
  4835 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4836 modelling and verification task performed in Isabelle/HOL +
  4837 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4838 
  4839 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4840 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4841 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4842 'domain', this makes the theory consistent with mathematical
  4843 literature;
  4844 
  4845 * HOL basics: added overloaded operations "inverse" and "divide"
  4846 (infix "/"), syntax for generic "abs" operation, generic summation
  4847 operator \<Sum>;
  4848 
  4849 * HOL/typedef: simplified package, provide more useful rules (see also
  4850 HOL/subset.thy);
  4851 
  4852 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4853 now expressed as a proper nested rule (old-style tactic scripts may
  4854 require atomize_strip_tac to cope with non-atomic premises);
  4855 
  4856 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4857 to "split_conv" (old name still available for compatibility);
  4858 
  4859 * HOL: improved concrete syntax for strings (e.g. allows translation
  4860 rules with string literals);
  4861 
  4862 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4863  and Fleuriot's mechanization of analysis, including the transcendental
  4864  functions for the reals;
  4865 
  4866 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4867 
  4868 
  4869 *** CTT ***
  4870 
  4871 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4872 "lam" is displayed as TWO lambda-symbols
  4873 
  4874 * CTT: theory Main now available, containing everything (that is, Bool
  4875 and Arith);
  4876 
  4877 
  4878 *** General ***
  4879 
  4880 * Pure: the Simplifier has been implemented properly as a derived rule
  4881 outside of the actual kernel (at last!); the overall performance
  4882 penalty in practical applications is about 50%, while reliability of
  4883 the Isabelle inference kernel has been greatly improved;
  4884 
  4885 * print modes "brackets" and "no_brackets" control output of nested =>
  4886 (types) and ==> (props); the default behaviour is "brackets";
  4887 
  4888 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4889 as assumptions as well;
  4890 
  4891 * system: support Poly/ML 4.0;
  4892 
  4893 * system: isatool install handles KDE version 1 or 2;
  4894 
  4895 
  4896 
  4897 New in Isabelle99-1 (October 2000)
  4898 ----------------------------------
  4899 
  4900 *** Overview of INCOMPATIBILITIES ***
  4901 
  4902 * HOL: simplification of natural numbers is much changed; to partly
  4903 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4904 issue the following ML commands:
  4905 
  4906   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4907   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4908 
  4909 * HOL: simplification no longer dives into case-expressions; this is
  4910 controlled by "t.weak_case_cong" for each datatype t;
  4911 
  4912 * HOL: nat_less_induct renamed to less_induct;
  4913 
  4914 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4915 fixsome to patch .thy and .ML sources automatically;
  4916 
  4917   select_equality  -> some_equality
  4918   select_eq_Ex     -> some_eq_ex
  4919   selectI2EX       -> someI2_ex
  4920   selectI2         -> someI2
  4921   selectI          -> someI
  4922   select1_equality -> some1_equality
  4923   Eps_sym_eq       -> some_sym_eq_trivial
  4924   Eps_eq           -> some_eq_trivial
  4925 
  4926 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4927 
  4928 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4929 instead);
  4930 
  4931 * HOL: the recursion equations generated by 'recdef' are now called
  4932 f.simps instead of f.rules;
  4933 
  4934 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4935 
  4936 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4937 sometimes be needed;
  4938 
  4939 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4940 
  4941 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4942 
  4943 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4944 product is now "<*>" instead of "Times"; the lexicographic product is
  4945 now "<*lex*>" instead of "**";
  4946 
  4947 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4948 of main HOL, but was unused); better use HOL's datatype package;
  4949 
  4950 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4951 the old syntax may be recovered as follows:
  4952 
  4953   syntax (symbols)
  4954     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4955       (infixl "\\<oplus>" 100)
  4956 
  4957 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4958 
  4959 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4960 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4961 internally;
  4962 
  4963 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4964 changed from A/r to A//r;
  4965 
  4966 * ZF: new treatment of arithmetic (nat & int) may break some old
  4967 proofs;
  4968 
  4969 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4970 rulify -> rule_format, elimify -> elim_format, ...);
  4971 
  4972 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4973 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4974 should have to change intro!! to intro? only); replaced "delrule" by
  4975 "rule del";
  4976 
  4977 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4978 
  4979 * Provers: strengthened force_tac by using new first_best_tac;
  4980 
  4981 * LaTeX document preparation: several changes of isabelle.sty (see
  4982 lib/texinputs);
  4983 
  4984 
  4985 *** Document preparation ***
  4986 
  4987 * formal comments (text blocks etc.) in new-style theories may now
  4988 contain antiquotations of thm/prop/term/typ/text to be presented
  4989 according to latex print mode; concrete syntax is like this:
  4990 @{term[show_types] "f(x) = a + x"};
  4991 
  4992 * isatool mkdir provides easy setup of Isabelle session directories,
  4993 including proper document sources;
  4994 
  4995 * generated LaTeX sources are now deleted after successful run
  4996 (isatool document -c); may retain a copy somewhere else via -D option
  4997 of isatool usedir;
  4998 
  4999 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5000 style files, achieving self-contained LaTeX sources and simplifying
  5001 LaTeX debugging;
  5002 
  5003 * old-style theories now produce (crude) LaTeX output as well;
  5004 
  5005 * browser info session directories are now self-contained (may be put
  5006 on WWW server seperately); improved graphs of nested sessions; removed
  5007 graph for 'all sessions';
  5008 
  5009 * several improvements in isabelle style files; \isabellestyle{it}
  5010 produces fake math mode output; \isamarkupheader is now \section by
  5011 default; see lib/texinputs/isabelle.sty etc.;
  5012 
  5013 
  5014 *** Isar ***
  5015 
  5016 * Isar/Pure: local results and corresponding term bindings are now
  5017 subject to Hindley-Milner polymorphism (similar to ML); this
  5018 accommodates incremental type-inference very nicely;
  5019 
  5020 * Isar/Pure: new derived language element 'obtain' supports
  5021 generalized existence reasoning;
  5022 
  5023 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5024 support accumulation of results, without applying any rules yet;
  5025 useful to collect intermediate results without explicit name
  5026 references, and for use with transitivity rules with more than 2
  5027 premises;
  5028 
  5029 * Isar/Pure: scalable support for case-analysis type proofs: new
  5030 'case' language element refers to local contexts symbolically, as
  5031 produced by certain proof methods; internally, case names are attached
  5032 to theorems as "tags";
  5033 
  5034 * Isar/Pure: theory command 'hide' removes declarations from
  5035 class/type/const name spaces;
  5036 
  5037 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5038 indicate potential overloading;
  5039 
  5040 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5041 
  5042 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5043 "{a,b,c}" instead of {a,b,c};
  5044 
  5045 * Isar/Pure now provides its own version of intro/elim/dest
  5046 attributes; useful for building new logics, but beware of confusion
  5047 with the version in Provers/classical;
  5048 
  5049 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5050 case name 'antecedent';
  5051 
  5052 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5053 to the current context is now done automatically);
  5054 
  5055 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5056 for definining proof methods in ML;
  5057 
  5058 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5059 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5060 most cases, one should have to change intro!! to intro? only);
  5061 replaced "delrule" by "rule del";
  5062 
  5063 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5064 'symmetric' attribute (the latter supercedes [RS sym]);
  5065 
  5066 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5067 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5068 well (including splits);
  5069 
  5070 * Isar/Provers: Simplifier and Classical methods now support all kind
  5071 of modifiers used in the past, including 'cong', 'iff', etc.
  5072 
  5073 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5074 of Simplifier and Classical reasoner);
  5075 
  5076 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5077 now support named cases; major packages (inductive, datatype, primrec,
  5078 recdef) support case names and properly name parameters;
  5079 
  5080 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5081 monotonicity conditions are extracted to be proven at end of
  5082 calculations;
  5083 
  5084 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5085 method anyway;
  5086 
  5087 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5088 split_if split_if_asm; datatype package provides theorems foo.splits =
  5089 foo.split foo.split_asm for each datatype;
  5090 
  5091 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5092 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5093 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5094 use "(cases (simplified))" method in proper proof texts);
  5095 
  5096 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5097 
  5098 * Isar: names of theorems etc. may be natural numbers as well;
  5099 
  5100 * Isar: 'pr' command: optional arguments for goals_limit and
  5101 ProofContext.prems_limit; no longer prints theory contexts, but only
  5102 proof states;
  5103 
  5104 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5105 additional print modes to be specified; e.g. "pr(latex)" will print
  5106 proof state according to the Isabelle LaTeX style;
  5107 
  5108 * Isar: improved support for emulating tactic scripts, including proof
  5109 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5110 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5111 (for HOL datatypes);
  5112 
  5113 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5114 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5115 'proof method scripts' have to be in depth-first order;
  5116 
  5117 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5118 
  5119 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5120 should instead use individual commands for printing items
  5121 (print_commands, print_methods etc.);
  5122 
  5123 * Isar: added 'nothing' --- the empty list of theorems;
  5124 
  5125 
  5126 *** HOL ***
  5127 
  5128 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5129 corresponding virtual machine and a specification of its bytecode
  5130 verifier and a lightweight bytecode verifier, including proofs of
  5131 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5132 Cornelia Pusch (see also the homepage of project Bali at
  5133 http://isabelle.in.tum.de/Bali/);
  5134 
  5135 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5136 Clemens Ballarin;
  5137 
  5138 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5139 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5140 Rasmussen;
  5141 
  5142 * HOL/Lattice: fundamental concepts of lattice theory and order
  5143 structures, including duals, properties of bounds versus algebraic
  5144 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5145 Theorem for complete lattices etc.; may also serve as a demonstration
  5146 for abstract algebraic reasoning using axiomatic type classes, and
  5147 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5148 
  5149 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5150 von Oheimb;
  5151 
  5152 * HOL/IMPP: extension of IMP with local variables and mutually
  5153 recursive procedures, by David von Oheimb;
  5154 
  5155 * HOL/Lambda: converted into new-style theory and document;
  5156 
  5157 * HOL/ex/Multiquote: example of multiple nested quotations and
  5158 anti-quotations -- basically a generalized version of de-Bruijn
  5159 representation; very useful in avoiding lifting of operations;
  5160 
  5161 * HOL/record: added general record equality rule to simpset; fixed
  5162 select-update simplification procedure to handle extended records as
  5163 well; admit "r" as field name;
  5164 
  5165 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5166 other numeric types and also as the identity of groups, rings, etc.;
  5167 
  5168 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5169 Types nat and int belong to this axclass;
  5170 
  5171 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5172    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5173    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5174   two terms #m*u and #n*u are replaced by #(m+n)*u
  5175     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5176   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5177     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5178 
  5179 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5180 powerful prover for predicate logic but knows nothing of clasets; see
  5181 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5182 
  5183 * HOL: new version of "case_tac" subsumes both boolean case split and
  5184 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5185 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5186 
  5187 * HOL: simplification no longer dives into case-expressions: only the
  5188 selector expression is simplified, but not the remaining arms; to
  5189 enable full simplification of case-expressions for datatype t, you may
  5190 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5191 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5192 
  5193 * HOL/recdef: the recursion equations generated by 'recdef' for
  5194 function 'f' are now called f.simps instead of f.rules; if all
  5195 termination conditions are proved automatically, these simplification
  5196 rules are added to the simpset, as in primrec; rules may be named
  5197 individually as well, resulting in a separate list of theorems for
  5198 each equation;
  5199 
  5200 * HOL/While is a new theory that provides a while-combinator. It
  5201 permits the definition of tail-recursive functions without the
  5202 provision of a termination measure. The latter is necessary once the
  5203 invariant proof rule for while is applied.
  5204 
  5205 * HOL: new (overloaded) notation for the set of elements below/above
  5206 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5207 
  5208 * HOL: theorems impI, allI, ballI bound as "strip";
  5209 
  5210 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5211 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5212 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5213 
  5214 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5215 
  5216 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5217 main HOL, but was unused);
  5218 
  5219 * HOL: fewer consts declared as global (e.g. have to refer to
  5220 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5221 
  5222 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5223 in case of overlap with user translations (e.g. judgements over
  5224 tuples); (note that the underlying logical represenation is still
  5225 bogus);
  5226 
  5227 
  5228 *** ZF ***
  5229 
  5230 * ZF: simplification automatically cancels common terms in arithmetic
  5231 expressions over nat and int;
  5232 
  5233 * ZF: new treatment of nat to minimize type-checking: all operators
  5234 coerce their operands to a natural number using the function natify,
  5235 making the algebraic laws unconditional;
  5236 
  5237 * ZF: as above, for int: operators coerce their operands to an integer
  5238 using the function intify;
  5239 
  5240 * ZF: the integer library now contains many of the usual laws for the
  5241 orderings, including $<=, and monotonicity laws for $+ and $*;
  5242 
  5243 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5244 simplification;
  5245 
  5246 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5247 to the simplifier and classical reasoner simultaneously;
  5248 
  5249 
  5250 *** General ***
  5251 
  5252 * Provers: blast_tac now handles actual object-logic rules as
  5253 assumptions; note that auto_tac uses blast_tac internally as well;
  5254 
  5255 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5256 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5257 
  5258 * Provers: delrules now handles destruct rules as well (no longer need
  5259 explicit make_elim);
  5260 
  5261 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5262   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5263 use instead the strong form,
  5264   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5265 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5266 from destruct-rules;
  5267 
  5268 * Provers: Simplifier.easy_setup provides a fast path to basic
  5269 Simplifier setup for new object-logics;
  5270 
  5271 * Pure: AST translation rules no longer require constant head on LHS;
  5272 
  5273 * Pure: improved name spaces: ambiguous output is qualified; support
  5274 for hiding of names;
  5275 
  5276 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5277 XSYMBOL_HOME; no longer need to do manual configuration in most
  5278 situations;
  5279 
  5280 * system: compression of ML heaps images may now be controlled via -c
  5281 option of isabelle and isatool usedir (currently only observed by
  5282 Poly/ML);
  5283 
  5284 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5285 useful for remote X11);
  5286 
  5287 * system: provide TAGS file for Isabelle sources;
  5288 
  5289 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5290 order;
  5291 
  5292 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5293 timing flag supersedes proof_timing and Toplevel.trace;
  5294 
  5295 * ML: new combinators |>> and |>>> for incremental transformations
  5296 with secondary results (e.g. certain theory extensions):
  5297 
  5298 * ML: PureThy.add_defs gets additional argument to indicate potential
  5299 overloading (usually false);
  5300 
  5301 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5302 results;
  5303 
  5304 
  5305 
  5306 New in Isabelle99 (October 1999)
  5307 --------------------------------
  5308 
  5309 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5310 
  5311 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5312 are no longer simplified.  (This allows the simplifier to unfold recursive
  5313 functional programs.)  To restore the old behaviour, declare
  5314 
  5315     Delcongs [if_weak_cong];
  5316 
  5317 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5318 complement;
  5319 
  5320 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5321 
  5322 * HOL/datatype: mutual_induct_tac no longer exists --
  5323   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5324 
  5325 * HOL/typedef: fixed type inference for representing set; type
  5326 arguments now have to occur explicitly on the rhs as type constraints;
  5327 
  5328 * ZF: The con_defs part of an inductive definition may no longer refer
  5329 to constants declared in the same theory;
  5330 
  5331 * HOL, ZF: the function mk_cases, generated by the inductive
  5332 definition package, has lost an argument.  To simplify its result, it
  5333 uses the default simpset instead of a supplied list of theorems.
  5334 
  5335 * HOL/List: the constructors of type list are now Nil and Cons;
  5336 
  5337 * Simplifier: the type of the infix ML functions
  5338         setSSolver addSSolver setSolver addSolver
  5339 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5340 for packaging solvers. A solver is created via
  5341         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5342 where the string argument is only a comment.
  5343 
  5344 
  5345 *** Proof tools ***
  5346 
  5347 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5348 decision procedure for linear arithmetic. Currently it is used for
  5349 types `nat', `int', and `real' in HOL (see below); it can, should and
  5350 will be instantiated for other types and logics as well.
  5351 
  5352 * The simplifier now accepts rewrite rules with flexible heads, eg
  5353      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5354   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5355   matching.
  5356 
  5357 
  5358 *** General ***
  5359 
  5360 * New Isabelle/Isar subsystem provides an alternative to traditional
  5361 tactical theorem proving; together with the ProofGeneral/isar user
  5362 interface it offers an interactive environment for developing human
  5363 readable proof documents (Isar == Intelligible semi-automated
  5364 reasoning); for further information see isatool doc isar-ref,
  5365 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5366 
  5367 * improved and simplified presentation of theories: better HTML markup
  5368 (including colors), graph views in several sizes; isatool usedir now
  5369 provides a proper interface for user theories (via -P option); actual
  5370 document preparation based on (PDF)LaTeX is available as well (for
  5371 new-style theories only); see isatool doc system for more information;
  5372 
  5373 * native support for Proof General, both for classic Isabelle and
  5374 Isabelle/Isar;
  5375 
  5376 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5377 using the graph browser tool;
  5378 
  5379 * Isabelle manuals now also available as PDF;
  5380 
  5381 * theory loader rewritten from scratch (may not be fully
  5382 bug-compatible); old loadpath variable has been replaced by show_path,
  5383 add_path, del_path, reset_path functions; new operations such as
  5384 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5385 isatool doc ref);
  5386 
  5387 * improved isatool install: option -k creates KDE application icon,
  5388 option -p DIR installs standalone binaries;
  5389 
  5390 * added ML_PLATFORM setting (useful for cross-platform installations);
  5391 more robust handling of platform specific ML images for SML/NJ;
  5392 
  5393 * the settings environment is now statically scoped, i.e. it is never
  5394 created again in sub-processes invoked from isabelle, isatool, or
  5395 Isabelle;
  5396 
  5397 * path element specification '~~' refers to '$ISABELLE_HOME';
  5398 
  5399 * in locales, the "assumes" and "defines" parts may be omitted if
  5400 empty;
  5401 
  5402 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5403 long arrows);
  5404 
  5405 * new print_mode "HTML";
  5406 
  5407 * new flag show_tags controls display of tags of theorems (which are
  5408 basically just comments that may be attached by some tools);
  5409 
  5410 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5411 mode and goal output format:
  5412 
  5413 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5414 244c244
  5415 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5416 ---
  5417 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5418 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5419 181c181
  5420 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5421 ---
  5422 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5423 
  5424 * function bind_thms stores lists of theorems (cf. bind_thm);
  5425 
  5426 * new shorthand tactics ftac, eatac, datac, fatac;
  5427 
  5428 * qed (and friends) now accept "" as result name; in that case the
  5429 theorem is not stored, but proper checks and presentation of the
  5430 result still apply;
  5431 
  5432 * theorem database now also indexes constants "Trueprop", "all",
  5433 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5434 
  5435 
  5436 *** HOL ***
  5437 
  5438 ** HOL arithmetic **
  5439 
  5440 * There are now decision procedures for linear arithmetic over nat and
  5441 int:
  5442 
  5443 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5444 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5445 are treated as atomic; subformulae not involving type `nat' or `int'
  5446 are ignored; quantified subformulae are ignored unless they are
  5447 positive universal or negative existential. The tactic has to be
  5448 invoked by hand and can be a little bit slow. In particular, the
  5449 running time is exponential in the number of occurrences of `min' and
  5450 `max', and `-' on `nat'.
  5451 
  5452 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5453 (negated) (in)equalities among the premises and the conclusion into
  5454 account (i.e. no compound formulae) and does not know about `min' and
  5455 `max', and `-' on `nat'. It is fast and is used automatically by the
  5456 simplifier.
  5457 
  5458 NB: At the moment, these decision procedures do not cope with mixed
  5459 nat/int formulae where the two parts interact, such as `m < n ==>
  5460 int(m) < int(n)'.
  5461 
  5462 * HOL/Numeral provides a generic theory of numerals (encoded
  5463 efficiently as bit strings); setup for types nat/int/real is in place;
  5464 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5465 int, existing theories and proof scripts may require a few additional
  5466 type constraints;
  5467 
  5468 * integer division and remainder can now be performed on constant
  5469 arguments;
  5470 
  5471 * many properties of integer multiplication, division and remainder
  5472 are now available;
  5473 
  5474 * An interface to the Stanford Validity Checker (SVC) is available through the
  5475 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5476 are proved automatically.  SVC must be installed separately, and its results
  5477 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5478 invocation of the underlying oracle).  For SVC see
  5479   http://verify.stanford.edu/SVC
  5480 
  5481 * IsaMakefile: the HOL-Real target now builds an actual image;
  5482 
  5483 
  5484 ** HOL misc **
  5485 
  5486 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5487 (in Isabelle/Isar) -- by Gertrud Bauer;
  5488 
  5489 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5490 analysis for assembly languages with subtypes;
  5491 
  5492 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5493 -- avoids syntactic ambiguities and treats state, transition, and
  5494 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5495 changed syntax and (many) tactics;
  5496 
  5497 * HOL/inductive: Now also handles more general introduction rules such
  5498   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5499   theorems are now maintained within the theory (maintained via the
  5500   "mono" attribute);
  5501 
  5502 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5503   (using function types) such as
  5504 
  5505   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5506 
  5507 * HOL/record: record_simproc (part of the default simpset) takes care
  5508 of selectors applied to updated records; record_split_tac is no longer
  5509 part of the default claset; update_defs may now be removed from the
  5510 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5511 
  5512   claset_ref () := claset() addSWrapper record_split_wrapper;
  5513   Delsimprocs [record_simproc]
  5514 
  5515 * HOL/typedef: fixed type inference for representing set; type
  5516 arguments now have to occur explicitly on the rhs as type constraints;
  5517 
  5518 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5519 names rather than an ML expression;
  5520 
  5521 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5522 supplied later.  Program schemes can be defined, such as
  5523     "While B C s = (if B s then While B C (C s) else s)"
  5524 where the well-founded relation can be chosen after B and C have been given.
  5525 
  5526 * HOL/List: the constructors of type list are now Nil and Cons;
  5527 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5528 course, ML tools referring to List.list.op # etc. have to be adapted;
  5529 
  5530 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5531 disabled by default; run isabelle with option -m HOL to get back to
  5532 the original Gordon/HOL-style output;
  5533 
  5534 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5535 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5536 
  5537 * HOL basic syntax simplified (more orthogonal): all variants of
  5538 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5539 Eps operator is provided as well: "SOME x. P[x]";
  5540 
  5541 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5542 
  5543 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5544 thus available for user theories;
  5545 
  5546 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5547 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5548 time;
  5549 
  5550 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5551 several times and then mp;
  5552 
  5553 
  5554 *** LK ***
  5555 
  5556 * the notation <<...>> is now available as a notation for sequences of
  5557 formulas;
  5558 
  5559 * the simplifier is now installed
  5560 
  5561 * the axiom system has been generalized (thanks to Soren Heilmann)
  5562 
  5563 * the classical reasoner now has a default rule database
  5564 
  5565 
  5566 *** ZF ***
  5567 
  5568 * new primrec section allows primitive recursive functions to be given
  5569 directly (as in HOL) over datatypes and the natural numbers;
  5570 
  5571 * new tactics induct_tac and exhaust_tac for induction (or case
  5572 analysis) over datatypes and the natural numbers;
  5573 
  5574 * the datatype declaration of type T now defines the recursor T_rec;
  5575 
  5576 * simplification automatically does freeness reasoning for datatype
  5577 constructors;
  5578 
  5579 * automatic type-inference, with AddTCs command to insert new
  5580 type-checking rules;
  5581 
  5582 * datatype introduction rules are now added as Safe Introduction rules
  5583 to the claset;
  5584 
  5585 * the syntax "if P then x else y" is now available in addition to
  5586 if(P,x,y);
  5587 
  5588 
  5589 *** Internal programming interfaces ***
  5590 
  5591 * tuned simplifier trace output; new flag debug_simp;
  5592 
  5593 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5594 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5595 
  5596 * AxClass.axclass_tac lost the theory argument;
  5597 
  5598 * tuned current_goals_markers semantics: begin / end goal avoids
  5599 printing empty lines;
  5600 
  5601 * removed prs and prs_fn hook, which was broken because it did not
  5602 include \n in its semantics, forcing writeln to add one
  5603 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5604 string -> unit if you really want to output text without newline;
  5605 
  5606 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5607 plain output, interface builders may have to enable 'isabelle_font'
  5608 mode to get Isabelle font glyphs as before;
  5609 
  5610 * refined token_translation interface; INCOMPATIBILITY: output length
  5611 now of type real instead of int;
  5612 
  5613 * theory loader actions may be traced via new ThyInfo.add_hook
  5614 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5615 your own database of information attached to *whole* theories -- as
  5616 opposed to intra-theory data slots offered via TheoryDataFun;
  5617 
  5618 * proper handling of dangling sort hypotheses (at last!);
  5619 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5620 extra sort hypotheses that can be witnessed from the type signature;
  5621 the force_strip_shyps flag is gone, any remaining shyps are simply
  5622 left in the theorem (with a warning issued by strip_shyps_warning);
  5623 
  5624 
  5625 
  5626 New in Isabelle98-1 (October 1998)
  5627 ----------------------------------
  5628 
  5629 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5630 
  5631 * several changes of automated proof tools;
  5632 
  5633 * HOL: major changes to the inductive and datatype packages, including
  5634 some minor incompatibilities of theory syntax;
  5635 
  5636 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5637 called `inj_on';
  5638 
  5639 * HOL: removed duplicate thms in Arith:
  5640   less_imp_add_less  should be replaced by  trans_less_add1
  5641   le_imp_add_le      should be replaced by  trans_le_add1
  5642 
  5643 * HOL: unary minus is now overloaded (new type constraints may be
  5644 required);
  5645 
  5646 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5647 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5648 now taken as an integer constant.
  5649 
  5650 * Pure: ML function 'theory_of' renamed to 'theory';
  5651 
  5652 
  5653 *** Proof tools ***
  5654 
  5655 * Simplifier:
  5656   1. Asm_full_simp_tac is now more aggressive.
  5657      1. It will sometimes reorient premises if that increases their power to
  5658         simplify.
  5659      2. It does no longer proceed strictly from left to right but may also
  5660         rotate premises to achieve further simplification.
  5661      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5662      old Asm_full_simp_tac in that it does not rotate premises.
  5663   2. The simplifier now knows a little bit about nat-arithmetic.
  5664 
  5665 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5666 allows for selected deletion of wrappers, by introduction of names for
  5667 wrapper functionals.  This implies that addbefore, addSbefore,
  5668 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5669 and that adding two tactics with the same name overwrites the first
  5670 one (emitting a warning).
  5671   type wrapper = (int -> tactic) -> (int -> tactic)
  5672   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5673   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5674   delWrapper, delSWrapper: claset *  string            -> claset
  5675   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5676 
  5677 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5678 semantics; addbefore now affects only the unsafe part of step_tac
  5679 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5680 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5681 by Force_tac;
  5682 
  5683 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5684 compWrapper; added safe wrapper (and access functions for it);
  5685 
  5686 * HOL/split_all_tac is now much faster and fails if there is nothing
  5687 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5688 and the names of the automatically generated variables have changed.
  5689 split_all_tac has moved within claset() from unsafe wrappers to safe
  5690 wrappers, which means that !!-bound variables are split much more
  5691 aggressively, and safe_tac and clarify_tac now split such variables.
  5692 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5693 Note: the same holds for record_split_tac, which does the job of
  5694 split_all_tac for record fields.
  5695 
  5696 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5697 permanently to the default simpset using Addsplits just like
  5698 Addsimps. They can be removed via Delsplits just like
  5699 Delsimps. Lower-case versions are also available.
  5700 
  5701 * HOL/Simplifier: The rule split_if is now part of the default
  5702 simpset. This means that the simplifier will eliminate all occurrences
  5703 of if-then-else in the conclusion of a goal. To prevent this, you can
  5704 either remove split_if completely from the default simpset by
  5705 `Delsplits [split_if]' or remove it in a specific call of the
  5706 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5707 other case splitting rules to/from the default simpset: every datatype
  5708 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5709 t is the name of the datatype).
  5710 
  5711 * Classical reasoner / Simplifier combination: new force_tac (and
  5712 derivatives Force_tac, force) combines rewriting and classical
  5713 reasoning (and whatever other tools) similarly to auto_tac, but is
  5714 aimed to solve the given subgoal completely.
  5715 
  5716 
  5717 *** General ***
  5718 
  5719 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5720 and `goalw': the theory is no longer needed as an explicit argument -
  5721 the current theory context is used; assumptions are no longer returned
  5722 at the ML-level unless one of them starts with ==> or !!; it is
  5723 recommended to convert to these new commands using isatool fixgoal
  5724 (backup your sources first!);
  5725 
  5726 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5727 the current theory context, and 'theory' to lookup stored theories;
  5728 
  5729 * new theory section 'locale' for declaring constants, assumptions and
  5730 definitions that have local scope;
  5731 
  5732 * new theory section 'nonterminals' for purely syntactic types;
  5733 
  5734 * new theory section 'setup' for generic ML setup functions
  5735 (e.g. package initialization);
  5736 
  5737 * the distribution now includes Isabelle icons: see
  5738 lib/logo/isabelle-{small,tiny}.xpm;
  5739 
  5740 * isatool install - install binaries with absolute references to
  5741 ISABELLE_HOME/bin;
  5742 
  5743 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5744 
  5745 * print mode 'emacs' reserved for Isamode;
  5746 
  5747 * support multiple print (ast) translations per constant name;
  5748 
  5749 * theorems involving oracles are now printed with a suffixed [!];
  5750 
  5751 
  5752 *** HOL ***
  5753 
  5754 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5755 
  5756 * HOL/inductive package reorganized and improved: now supports mutual
  5757 definitions such as
  5758 
  5759   inductive EVEN ODD
  5760     intrs
  5761       null "0 : EVEN"
  5762       oddI "n : EVEN ==> Suc n : ODD"
  5763       evenI "n : ODD ==> Suc n : EVEN"
  5764 
  5765 new theorem list "elims" contains an elimination rule for each of the
  5766 recursive sets; inductive definitions now handle disjunctive premises
  5767 correctly (also ZF);
  5768 
  5769 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5770 "mutual_induct" no longer exists - the induction rule is always
  5771 contained in "induct";
  5772 
  5773 
  5774 * HOL/datatype package re-implemented and greatly improved: now
  5775 supports mutually recursive datatypes such as
  5776 
  5777   datatype
  5778     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5779             | SUM ('a aexp) ('a aexp)
  5780             | DIFF ('a aexp) ('a aexp)
  5781             | NUM 'a
  5782   and
  5783     'a bexp = LESS ('a aexp) ('a aexp)
  5784             | AND ('a bexp) ('a bexp)
  5785             | OR ('a bexp) ('a bexp)
  5786 
  5787 as well as indirectly recursive datatypes such as
  5788 
  5789   datatype
  5790     ('a, 'b) term = Var 'a
  5791                   | App 'b ((('a, 'b) term) list)
  5792 
  5793 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5794 induction on mutually / indirectly recursive datatypes.
  5795 
  5796 Primrec equations are now stored in theory and can be accessed via
  5797 <function_name>.simps.
  5798 
  5799 INCOMPATIBILITIES:
  5800 
  5801   - Theories using datatypes must now have theory Datatype as an
  5802     ancestor.
  5803   - The specific <typename>.induct_tac no longer exists - use the
  5804     generic induct_tac instead.
  5805   - natE has been renamed to nat.exhaust - use exhaust_tac
  5806     instead of res_inst_tac ... natE. Note that the variable
  5807     names in nat.exhaust differ from the names in natE, this
  5808     may cause some "fragile" proofs to fail.
  5809   - The theorems split_<typename>_case and split_<typename>_case_asm
  5810     have been renamed to <typename>.split and <typename>.split_asm.
  5811   - Since default sorts of type variables are now handled correctly,
  5812     some datatype definitions may have to be annotated with explicit
  5813     sort constraints.
  5814   - Primrec definitions no longer require function name and type
  5815     of recursive argument.
  5816 
  5817 Consider using isatool fixdatatype to adapt your theories and proof
  5818 scripts to the new package (backup your sources first!).
  5819 
  5820 
  5821 * HOL/record package: considerably improved implementation; now
  5822 includes concrete syntax for record types, terms, updates; theorems
  5823 for surjective pairing and splitting !!-bound record variables; proof
  5824 support is as follows:
  5825 
  5826   1) standard conversions (selectors or updates applied to record
  5827 constructor terms) are part of the standard simpset;
  5828 
  5829   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5830 made part of standard simpset and claset via addIffs;
  5831 
  5832   3) a tactic for record field splitting (record_split_tac) is part of
  5833 the standard claset (addSWrapper);
  5834 
  5835 To get a better idea about these rules you may retrieve them via
  5836 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5837 the name of your record type.
  5838 
  5839 The split tactic 3) conceptually simplifies by the following rule:
  5840 
  5841   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5842 
  5843 Thus any record variable that is bound by meta-all will automatically
  5844 blow up into some record constructor term, consequently the
  5845 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5846 solve record problems automatically.
  5847 
  5848 
  5849 * reorganized the main HOL image: HOL/Integ and String loaded by
  5850 default; theory Main includes everything;
  5851 
  5852 * automatic simplification of integer sums and comparisons, using cancellation;
  5853 
  5854 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5855 
  5856 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5857 
  5858 * many new identities for unions, intersections, set difference, etc.;
  5859 
  5860 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5861 called split_if, split_split, split_sum_case and split_nat_case (to go
  5862 with add/delsplits);
  5863 
  5864 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5865 (?x::unit) = (); this is made part of the default simpset, which COULD
  5866 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5867 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5868 unit_abs_eta_conv is added in order to counter the effect of
  5869 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5870 %u.f();
  5871 
  5872 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5873 makes more sense);
  5874 
  5875 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5876   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5877   disjointness reasoning but breaking a few old proofs.
  5878 
  5879 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5880 to 'converse' from 'inverse' (for compatibility with ZF and some
  5881 literature);
  5882 
  5883 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5884 the well-founded relation;
  5885 
  5886 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5887     Compl A.  The "Compl" syntax remains available as input syntax for this
  5888     release ONLY.
  5889 
  5890 * HOL/Update: new theory of function updates:
  5891     f(a:=b) == %x. if x=a then b else f x
  5892 may also be iterated as in f(a:=b,c:=d,...);
  5893 
  5894 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5895 
  5896 * HOL/List:
  5897   - new function list_update written xs[i:=v] that updates the i-th
  5898     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5899   - new function `upt' written [i..j(] which generates the list
  5900     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5901     bound write [i..j], which is a shorthand for [i..j+1(].
  5902   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5903 
  5904 * HOL/Arith:
  5905   - removed 'pred' (predecessor) function;
  5906   - generalized some theorems about n-1;
  5907   - many new laws about "div" and "mod";
  5908   - new laws about greatest common divisors (see theory ex/Primes);
  5909 
  5910 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5911 instead of "inverse";
  5912 
  5913 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5914   of the multiset ordering;
  5915 
  5916 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5917   (not included by default);
  5918 
  5919 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5920 
  5921 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5922   programs, i.e. different program variables may have different types.
  5923 
  5924 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5925   [previously, this check worked only if the rewrite rule was unconditional]
  5926   Now rew can involve either definitions or equalities (either == or =).
  5927 
  5928 
  5929 *** ZF ***
  5930 
  5931 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5932   only the theorems proved on ZF.ML;
  5933 
  5934 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5935   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5936   disjointness reasoning but breaking a few old proofs.
  5937 
  5938 * ZF/Update: new theory of function updates
  5939     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5940   may also be iterated as in f(a:=b,c:=d,...);
  5941 
  5942 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5943 
  5944 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5945   [previously, this check worked only if the rewrite rule was unconditional]
  5946   Now rew can involve either definitions or equalities (either == or =).
  5947 
  5948 * case_tac provided for compatibility with HOL
  5949     (like the old excluded_middle_tac, but with subgoals swapped)
  5950 
  5951 
  5952 *** Internal programming interfaces ***
  5953 
  5954 * Pure: several new basic modules made available for general use, see
  5955 also src/Pure/README;
  5956 
  5957 * improved the theory data mechanism to support encapsulation (data
  5958 kind name replaced by private Object.kind, acting as authorization
  5959 key); new type-safe user interface via functor TheoryDataFun; generic
  5960 print_data function becomes basically useless;
  5961 
  5962 * removed global_names compatibility flag -- all theory declarations
  5963 are qualified by default;
  5964 
  5965 * module Pure/Syntax now offers quote / antiquote translation
  5966 functions (useful for Hoare logic etc. with implicit dependencies);
  5967 see HOL/ex/Antiquote for an example use;
  5968 
  5969 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5970 cterm -> thm;
  5971 
  5972 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5973 subgoal;
  5974 
  5975 * Display.print_goals function moved to Locale.print_goals;
  5976 
  5977 * standard print function for goals supports current_goals_markers
  5978 variable for marking begin of proof, end of proof, start of goal; the
  5979 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5980 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5981 for example;
  5982 
  5983 
  5984 
  5985 New in Isabelle98 (January 1998)
  5986 --------------------------------
  5987 
  5988 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5989 
  5990 * changed lexical syntax of terms / types: dots made part of long
  5991 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5992 
  5993 * simpset (and claset) reference variable replaced by functions
  5994 simpset / simpset_ref;
  5995 
  5996 * no longer supports theory aliases (via merge) and non-trivial
  5997 implicit merge of thms' signatures;
  5998 
  5999 * most internal names of constants changed due to qualified names;
  6000 
  6001 * changed Pure/Sequence interface (see Pure/seq.ML);
  6002 
  6003 
  6004 *** General Changes ***
  6005 
  6006 * hierachically structured name spaces (for consts, types, axms, thms
  6007 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6008 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6009 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6010 long_names for fully qualified output names; NOTE: ML programs
  6011 (special tactics, packages etc.) referring to internal names may have
  6012 to be adapted to cope with fully qualified names; in case of severe
  6013 backward campatibility problems try setting 'global_names' at compile
  6014 time to have enrything declared within a flat name space; one may also
  6015 fine tune name declarations in theories via the 'global' and 'local'
  6016 section;
  6017 
  6018 * reimplemented the implicit simpset and claset using the new anytype
  6019 data filed in signatures; references simpset:simpset ref etc. are
  6020 replaced by functions simpset:unit->simpset and
  6021 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6022 to patch your ML files accordingly;
  6023 
  6024 * HTML output now includes theory graph data for display with Java
  6025 applet or isatool browser; data generated automatically via isatool
  6026 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6027 
  6028 * defs may now be conditional; improved rewrite_goals_tac to handle
  6029 conditional equations;
  6030 
  6031 * defs now admits additional type arguments, using TYPE('a) syntax;
  6032 
  6033 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6034 creates a new theory node; implicit merge of thms' signatures is
  6035 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6036 transfer:theory->thm->thm in (rare) cases;
  6037 
  6038 * improved handling of draft signatures / theories; draft thms (and
  6039 ctyps, cterms) are automatically promoted to real ones;
  6040 
  6041 * slightly changed interfaces for oracles: admit many per theory, named
  6042 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6043 
  6044 * print_goals: optional output of const types (set show_consts and
  6045 show_types);
  6046 
  6047 * improved output of warnings (###) and errors (***);
  6048 
  6049 * subgoal_tac displays a warning if the new subgoal has type variables;
  6050 
  6051 * removed old README and Makefiles;
  6052 
  6053 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6054 
  6055 * removed obsolete init_pps and init_database;
  6056 
  6057 * deleted the obsolete tactical STATE, which was declared by
  6058     fun STATE tacfun st = tacfun st st;
  6059 
  6060 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6061 (which abbreviates $HOME);
  6062 
  6063 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6064 use isatool fixseq to adapt your ML programs (this works for fully
  6065 qualified references to the Sequence structure only!);
  6066 
  6067 * use_thy no longer requires writable current directory; it always
  6068 reloads .ML *and* .thy file, if either one is out of date;
  6069 
  6070 
  6071 *** Classical Reasoner ***
  6072 
  6073 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6074 tactics that use classical reasoning to simplify a subgoal without
  6075 splitting it into several subgoals;
  6076 
  6077 * Safe_tac: like safe_tac but uses the default claset;
  6078 
  6079 
  6080 *** Simplifier ***
  6081 
  6082 * added simplification meta rules:
  6083     (asm_)(full_)simplify: simpset -> thm -> thm;
  6084 
  6085 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6086 logics (again);
  6087 
  6088 * added prems argument to simplification procedures;
  6089 
  6090 * HOL, FOL, ZF: added infix function `addsplits':
  6091   instead of `<simpset> setloop (split_tac <thms>)'
  6092   you can simply write `<simpset> addsplits <thms>'
  6093 
  6094 
  6095 *** Syntax ***
  6096 
  6097 * TYPE('a) syntax for type reflection terms;
  6098 
  6099 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6100 
  6101 * pretty printer: changed order of mixfix annotation preference (again!);
  6102 
  6103 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6104 
  6105 
  6106 *** HOL ***
  6107 
  6108 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6109   with `addloop' of the simplifier to faciliate case splitting in premises.
  6110 
  6111 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6112 
  6113 * HOL/Auth: new protocol proofs including some for the Internet
  6114   protocol TLS;
  6115 
  6116 * HOL/Map: new theory of `maps' a la VDM;
  6117 
  6118 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6119 cancelling out common nat summands from =, <, <= (in)equalities, or
  6120 differences; simplification procedures nat_cancel_factor for
  6121 cancelling common factor from =, <, <= (in)equalities over natural
  6122 sums; nat_cancel contains both kinds of procedures, it is installed by
  6123 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6124 
  6125 * HOL/simplifier: terms of the form
  6126   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6127   are rewritten to
  6128   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6129   and those of the form
  6130   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6131   are rewritten to
  6132   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6133 
  6134 * HOL/datatype
  6135   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6136 
  6137   P(t_case f1 ... fn x) =
  6138      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6139         ...
  6140        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6141      )
  6142 
  6143   and a theorem `split_t_case_asm' of the form
  6144 
  6145   P(t_case f1 ... fn x) =
  6146     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6147         ...
  6148        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6149      )
  6150   which can be added to a simpset via `addsplits'. The existing theorems
  6151   expand_list_case and expand_option_case have been renamed to
  6152   split_list_case and split_option_case.
  6153 
  6154 * HOL/Arithmetic:
  6155   - `pred n' is automatically converted to `n-1'.
  6156     Users are strongly encouraged not to use `pred' any longer,
  6157     because it will disappear altogether at some point.
  6158   - Users are strongly encouraged to write "0 < n" rather than
  6159     "n ~= 0". Theorems and proof tools have been modified towards this
  6160     `standard'.
  6161 
  6162 * HOL/Lists:
  6163   the function "set_of_list" has been renamed "set" (and its theorems too);
  6164   the function "nth" now takes its arguments in the reverse order and
  6165   has acquired the infix notation "!" as in "xs!n".
  6166 
  6167 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6168 
  6169 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6170   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6171 
  6172 * HOL/record: extensible records with schematic structural subtyping
  6173 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6174 still lacks various theorems and concrete record syntax;
  6175 
  6176 
  6177 *** HOLCF ***
  6178 
  6179 * removed "axioms" and "generated by" sections;
  6180 
  6181 * replaced "ops" section by extended "consts" section, which is capable of
  6182   handling the continuous function space "->" directly;
  6183 
  6184 * domain package:
  6185   . proves theorems immediately and stores them in the theory,
  6186   . creates hierachical name space,
  6187   . now uses normal mixfix annotations (instead of cinfix...),
  6188   . minor changes to some names and values (for consistency),
  6189   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6190   . separator between mutual domain defs: changed "," to "and",
  6191   . improved handling of sort constraints;  now they have to
  6192     appear on the left-hand side of the equations only;
  6193 
  6194 * fixed LAM <x,y,zs>.b syntax;
  6195 
  6196 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6197 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6198 
  6199 
  6200 *** FOL and ZF ***
  6201 
  6202 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6203   with `addloop' of the simplifier to faciliate case splitting in premises.
  6204 
  6205 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6206 in HOL, they strip ALL and --> from proved theorems;
  6207 
  6208 
  6209 
  6210 New in Isabelle94-8 (May 1997)
  6211 ------------------------------
  6212 
  6213 *** General Changes ***
  6214 
  6215 * new utilities to build / run / maintain Isabelle etc. (in parts
  6216 still somewhat experimental); old Makefiles etc. still functional;
  6217 
  6218 * new 'Isabelle System Manual';
  6219 
  6220 * INSTALL text, together with ./configure and ./build scripts;
  6221 
  6222 * reimplemented type inference for greater efficiency, better error
  6223 messages and clean internal interface;
  6224 
  6225 * prlim command for dealing with lots of subgoals (an easier way of
  6226 setting goals_limit);
  6227 
  6228 
  6229 *** Syntax ***
  6230 
  6231 * supports alternative (named) syntax tables (parser and pretty
  6232 printer); internal interface is provided by add_modesyntax(_i);
  6233 
  6234 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6235 be used in conjunction with the Isabelle symbol font; uses the
  6236 "symbols" syntax table;
  6237 
  6238 * added token_translation interface (may translate name tokens in
  6239 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6240 the current print_mode); IMPORTANT: user print translation functions
  6241 are responsible for marking newly introduced bounds
  6242 (Syntax.mark_boundT);
  6243 
  6244 * token translations for modes "xterm" and "xterm_color" that display
  6245 names in bold, underline etc. or colors (which requires a color
  6246 version of xterm);
  6247 
  6248 * infixes may now be declared with names independent of their syntax;
  6249 
  6250 * added typed_print_translation (like print_translation, but may
  6251 access type of constant);
  6252 
  6253