NEWS
author haftmann
Wed Sep 23 14:00:43 2009 +0200 (2009-09-23)
changeset 32701 5059a733a4b8
parent 32697 72e8608dce54
child 32706 b68f3afdc137
permissions -rw-r--r--
merged
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    10 one backslash should be used, even in ML sources.
    11 
    12 
    13 *** Pure ***
    14 
    15 * On instantiation of classes, remaining undefined class parameters
    16 are formally declared.  INCOMPATIBILITY.
    17 
    18 
    19 *** HOL ***
    20 
    21 * New proof method "smt" for a combination of first-order logic
    22 with equality, linear and nonlinear (natural/integer/real)
    23 arithmetic, and fixed-size bitvectors; there is also basic
    24 support for higher-order features (esp. lambda abstractions).
    25 It is an incomplete decision procedure based on external SMT
    26 solvers using the oracle mechanism.
    27 
    28 * Reorganization of number theory:
    29   * former session NumberTheory now named Old_Number_Theory
    30   * new session Number_Theory by Jeremy Avigad; if possible, prefer this.
    31   * moved legacy theories Legacy_GCD and Primes from Library/ to Old_Number_Theory/;
    32   * moved theory Pocklington from Library/ to Old_Number_Theory/;
    33   * removed various references to Old_Number_Theory from HOL distribution.
    34 INCOMPATIBILITY.
    35 
    36 * Theory GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm
    37 of finite and infinite sets. It is shown that they form a complete
    38 lattice.
    39 
    40 * Split off prime number ingredients from theory GCD
    41 to theory Number_Theory/Primes;
    42 
    43 * Class semiring_div requires superclass no_zero_divisors and proof of
    44 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    45 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    46 generalized to class semiring_div, subsuming former theorems
    47 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    48 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    49 INCOMPATIBILITY.
    50 
    51 * New testing tool "Mirabelle" for automated (proof) tools. Applies
    52 several tools and tactics like sledgehammer, metis, or quickcheck, to
    53 every proof step in a theory. To be used in batch mode via the
    54 "mirabelle" utility.
    55 
    56 * New proof method "sos" (sum of squares) for nonlinear real
    57 arithmetic (originally due to John Harison). It requires
    58 Library/Sum_Of_Squares.  It is not a complete decision procedure but
    59 works well in practice on quantifier-free real arithmetic with +, -,
    60 *, ^, =, <= and <, i.e. boolean combinations of equalities and
    61 inequalities between polynomials. It makes use of external
    62 semidefinite programming solvers.  For more information and examples
    63 see src/HOL/Library/Sum_Of_Squares.
    64 
    65 * Code generator attributes follow the usual underscore convention:
    66     code_unfold     replaces    code unfold
    67     code_post       replaces    code post
    68     etc.
    69   INCOMPATIBILITY.
    70 
    71 * Refinements to lattice classes and sets:
    72   - less default intro/elim rules in locale variant, more default
    73     intro/elim rules in class variant: more uniformity
    74   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
    75   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
    76   - renamed ACI to inf_sup_aci
    77   - new class "boolean_algebra"
    78   - class "complete_lattice" moved to separate theory "complete_lattice";
    79     corresponding constants (and abbreviations) renamed and with authentic syntax:
    80     Set.Inf ~>      Complete_Lattice.Inf
    81     Set.Sup ~>      Complete_Lattice.Sup
    82     Set.INFI ~>     Complete_Lattice.INFI
    83     Set.SUPR ~>     Complete_Lattice.SUPR
    84     Set.Inter ~>    Complete_Lattice.Inter
    85     Set.Union ~>    Complete_Lattice.Union
    86     Set.INTER ~>    Complete_Lattice.INTER
    87     Set.UNION ~>    Complete_Lattice.UNION
    88   - more convenient names for set intersection and union:
    89     Set.Int ~>      Set.inter
    90     Set.Un ~>       Set.union
    91   - authentic syntax for
    92     Set.Pow
    93     Set.image
    94   - mere abbreviations:
    95     Set.empty               (for bot)
    96     Set.UNIV                (for top)
    97     Set.inter               (for inf)
    98     Set.union               (for sup)
    99     Complete_Lattice.Inter  (for Inf)
   100     Complete_Lattice.Union  (for Sup)
   101     Complete_Lattice.INTER  (for INFI)
   102     Complete_Lattice.UNION  (for SUPR)
   103   - object-logic definitions as far as appropriate
   104 
   105 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   106 Un_subset_iff are explicitly deleted as default simp rules;  then
   107 also their lattice counterparts le_inf_iff and le_sup_iff have to be
   108 deleted to achieve the desired effect.
   109 
   110 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no
   111 simp rules by default any longer.  The same applies to
   112 min_max.inf_absorb1 etc.!  INCOMPATIBILITY.
   113 
   114 * Power operations on relations and functions are now one dedicate
   115 constant "compow" with infix syntax "^^".  Power operations on
   116 multiplicative monoids retains syntax "^" and is now defined generic
   117 in class power.  INCOMPATIBILITY.
   118 
   119 * Relation composition "R O S" now has a "more standard" argument
   120 order, i.e., "R O S = {(x,z). EX y. (x,y) : R & (y,z) : S }".
   121 INCOMPATIBILITY: Rewrite propositions with "S O R" --> "R O S". Proofs
   122 may occationally break, since the O_assoc rule was not rewritten like
   123 this.  Fix using O_assoc[symmetric].  The same applies to the curried
   124 version "R OO S".
   125 
   126 * ML antiquotation @{code_datatype} inserts definition of a datatype
   127 generated by the code generator; see Predicate.thy for an example.
   128 
   129 * New method "linarith" invokes existing linear arithmetic decision
   130 procedure only.
   131 
   132 * New implementation of quickcheck uses generic code generator;
   133 default generators are provided for all suitable HOL types, records
   134 and datatypes.
   135 
   136 * Renamed theorems:
   137 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   138 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   139 Suc_plus1 -> Suc_eq_plus1
   140 
   141 * Moved theorems:
   142 Wellfounded.in_inv_image -> Relation.in_inv_image
   143 
   144 * New sledgehammer option "Full Types" in Proof General settings menu.
   145 Causes full type information to be output to the ATPs.  This slows
   146 ATPs down considerably but eliminates a source of unsound "proofs"
   147 that fail later.
   148 
   149 * New method metisFT: A version of metis that uses full type information
   150 in order to avoid failures of proof reconstruction.
   151 
   152 * Discontinued ancient tradition to suffix certain ML module names
   153 with "_package", e.g.:
   154 
   155     DatatypePackage ~> Datatype
   156     InductivePackage ~> Inductive
   157 
   158 INCOMPATIBILITY.
   159 
   160 * Discontinued abbreviation "arbitrary" of constant
   161 "undefined". INCOMPATIBILITY, use "undefined" directly.
   162 
   163 * New evaluator "approximate" approximates an real valued term using
   164 the same method as the approximation method.
   165 
   166 * Method "approximate" supports now arithmetic expressions as
   167 boundaries of intervals and implements interval splitting and Taylor
   168 series expansion.
   169 
   170 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   171 the theorems in DERIV_intros assumes composition with an additional
   172 function and matches a variable to the derivative, which has to be
   173 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   174 the derivative of most elementary terms.
   175 
   176 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   177 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   178 
   179 
   180 *** ML ***
   181 
   182 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   183 parallel tactical reasoning.
   184 
   185 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   186 are similar to SUBPROOF, but are slightly more flexible: only the
   187 specified parts of the subgoal are imported into the context, and the
   188 body tactic may introduce new subgoals and schematic variables.
   189 
   190 * Old tactical METAHYPS, which does not observe the proof context, has
   191 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   192 or Subgoal.FOCUS etc.
   193 
   194 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   195 functors have their own ML name space there is no point to mark them
   196 separately.)  Minor INCOMPATIBILITY.
   197 
   198 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   199 
   200 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   201 cominators for "args".  INCOMPATIBILITY, need to use simplified
   202 Attrib/Method.setup introduced in Isabelle2009.
   203 
   204 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   205 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   206 last resort.  INCOMPATIBILITY.
   207 
   208 * Display.pretty_thm now requires a proper context (cf. former
   209 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   210 or even Display.pretty_thm_without_context as last resort.
   211 INCOMPATIBILITY.
   212 
   213 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   214 Syntax.pretty_typ/term directly, preferably with proper context
   215 instead of global theory.
   216 
   217 
   218 *** System ***
   219 
   220 * Support for additional "Isabelle components" via etc/components, see
   221 also the system manual.
   222 
   223 * The isabelle makeall tool now operates on all components with
   224 IsaMakefile, not just hardwired "logics".
   225 
   226 * Discontinued support for Poly/ML 4.x versions.
   227 
   228 * Removed "compress" option from isabelle-process and isabelle usedir;
   229 this is always enabled.
   230 
   231 * More fine-grained control of proof parallelism, cf.
   232 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   233 
   234 
   235 
   236 New in Isabelle2009 (April 2009)
   237 --------------------------------
   238 
   239 *** General ***
   240 
   241 * Simplified main Isabelle executables, with less surprises on
   242 case-insensitive file-systems (such as Mac OS).
   243 
   244   - The main Isabelle tool wrapper is now called "isabelle" instead of
   245     "isatool."
   246 
   247   - The former "isabelle" alias for "isabelle-process" has been
   248     removed (should rarely occur to regular users).
   249 
   250   - The former "isabelle-interface" and its alias "Isabelle" have been
   251     removed (interfaces are now regular Isabelle tools).
   252 
   253 Within scripts and make files, the Isabelle environment variables
   254 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   255 respectively.  (The latter are still available as legacy feature.)
   256 
   257 The old isabelle-interface wrapper could react in confusing ways if
   258 the interface was uninstalled or changed otherwise.  Individual
   259 interface tool configuration is now more explicit, see also the
   260 Isabelle system manual.  In particular, Proof General is now available
   261 via "isabelle emacs".
   262 
   263 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   264 purge installed copies of Isabelle executables and re-run "isabelle
   265 install -p ...", or use symlinks.
   266 
   267 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   268 old ~/isabelle, which was slightly non-standard and apt to cause
   269 surprises on case-insensitive file-systems (such as Mac OS).
   270 
   271 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   272 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   273 care is required when using older releases of Isabelle.  Note that
   274 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   275 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   276 
   277 * Proofs of fully specified statements are run in parallel on
   278 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   279 a regular 4-core machine, if the initial heap space is made reasonably
   280 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   281 
   282 * The main reference manuals ("isar-ref", "implementation", and
   283 "system") have been updated and extended.  Formally checked references
   284 as hyperlinks are now available uniformly.
   285 
   286 
   287 *** Pure ***
   288 
   289 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   290 respects.  The most important changes are listed below.  See the
   291 Tutorial on Locales ("locales" manual) for details.
   292 
   293 - In locale expressions, instantiation replaces renaming.  Parameters
   294 must be declared in a for clause.  To aid compatibility with previous
   295 parameter inheritance, in locale declarations, parameters that are not
   296 'touched' (instantiation position "_" or omitted) are implicitly added
   297 with their syntax at the beginning of the for clause.
   298 
   299 - Syntax from abbreviations and definitions in locales is available in
   300 locale expressions and context elements.  The latter is particularly
   301 useful in locale declarations.
   302 
   303 - More flexible mechanisms to qualify names generated by locale
   304 expressions.  Qualifiers (prefixes) may be specified in locale
   305 expressions, and can be marked as mandatory (syntax: "name!:") or
   306 optional (syntax "name?:").  The default depends for plain "name:"
   307 depends on the situation where a locale expression is used: in
   308 commands 'locale' and 'sublocale' prefixes are optional, in
   309 'interpretation' and 'interpret' prefixes are mandatory.  The old
   310 implicit qualifiers derived from the parameter names of a locale are
   311 no longer generated.
   312 
   313 - Command "sublocale l < e" replaces "interpretation l < e".  The
   314 instantiation clause in "interpretation" and "interpret" (square
   315 brackets) is no longer available.  Use locale expressions.
   316 
   317 - When converting proof scripts, mandatory qualifiers in
   318 'interpretation' and 'interpret' should be retained by default, even
   319 if this is an INCOMPATIBILITY compared to former behavior.  In the
   320 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   321 in locale expressions range over a single locale instance only.
   322 
   323 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   324 In existing theorem specifications replace the includes element by the
   325 respective context elements of the included locale, omitting those
   326 that are already present in the theorem specification.  Multiple
   327 assume elements of a locale should be replaced by a single one
   328 involving the locale predicate.  In the proof body, declarations (most
   329 notably theorems) may be regained by interpreting the respective
   330 locales in the proof context as required (command "interpret").
   331 
   332 If using "includes" in replacement of a target solely because the
   333 parameter types in the theorem are not as general as in the target,
   334 consider declaring a new locale with additional type constraints on
   335 the parameters (context element "constrains").
   336 
   337 - Discontinued "locale (open)".  INCOMPATIBILITY.
   338 
   339 - Locale interpretation commands no longer attempt to simplify goal.
   340 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   341 methods intro_locales and unfold_locales to clarify.
   342 
   343 - Locale interpretation commands no longer accept interpretation
   344 attributes.  INCOMPATIBILITY.
   345 
   346 * Class declaration: so-called "base sort" must not be given in import
   347 list any longer, but is inferred from the specification.  Particularly
   348 in HOL, write
   349 
   350     class foo = ...
   351 
   352 instead of
   353 
   354     class foo = type + ...
   355 
   356 * Class target: global versions of theorems stemming do not carry a
   357 parameter prefix any longer.  INCOMPATIBILITY.
   358 
   359 * Class 'instance' command no longer accepts attached definitions.
   360 INCOMPATIBILITY, use proper 'instantiation' target instead.
   361 
   362 * Recovered hiding of consts, which was accidentally broken in
   363 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   364 makes c inaccessible; consider using ``hide (open) const c'' instead.
   365 
   366 * Slightly more coherent Pure syntax, with updated documentation in
   367 isar-ref manual.  Removed locales meta_term_syntax and
   368 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   369 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   370 directly in regular applications.
   371 
   372 * There is a new syntactic category "float_const" for signed decimal
   373 fractions (e.g. 123.45 or -123.45).
   374 
   375 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   376 interface with 'setup' command instead.
   377 
   378 * Command 'local_setup' is similar to 'setup', but operates on a local
   379 theory context.
   380 
   381 * The 'axiomatization' command now only works within a global theory
   382 context.  INCOMPATIBILITY.
   383 
   384 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   385 hypotheses.  Sorts required in the course of reasoning need to be
   386 covered by the constraints in the initial statement, completed by the
   387 type instance information of the background theory.  Non-trivial sort
   388 hypotheses, which rarely occur in practice, may be specified via
   389 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   390 
   391   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   392 
   393 The result contains an implicit sort hypotheses as before --
   394 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   395 normalization.
   396 
   397 * Generalized Isar history, with support for linear undo, direct state
   398 addressing etc.
   399 
   400 * Changed defaults for unify configuration options:
   401 
   402   unify_trace_bound = 50 (formerly 25)
   403   unify_search_bound = 60 (formerly 30)
   404 
   405 * Different bookkeeping for code equations (INCOMPATIBILITY):
   406 
   407   a) On theory merge, the last set of code equations for a particular
   408      constant is taken (in accordance with the policy applied by other
   409      parts of the code generator framework).
   410 
   411   b) Code equations stemming from explicit declarations (e.g. code
   412      attribute) gain priority over default code equations stemming
   413      from definition, primrec, fun etc.
   414 
   415 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   416 
   417 * Unified theorem tables for both code generators.  Thus [code
   418 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   419 
   420 * Command 'find_consts' searches for constants based on type and name
   421 patterns, e.g.
   422 
   423     find_consts "_ => bool"
   424 
   425 By default, matching is against subtypes, but it may be restricted to
   426 the whole type.  Searching by name is possible.  Multiple queries are
   427 conjunctive and queries may be negated by prefixing them with a
   428 hyphen:
   429 
   430     find_consts strict: "_ => bool" name: "Int" -"int => int"
   431 
   432 * New 'find_theorems' criterion "solves" matches theorems that
   433 directly solve the current goal (modulo higher-order unification).
   434 
   435 * Auto solve feature for main theorem statements: whenever a new goal
   436 is stated, "find_theorems solves" is called; any theorems that could
   437 solve the lemma directly are listed as part of the goal state.
   438 Cf. associated options in Proof General Isabelle settings menu,
   439 enabled by default, with reasonable timeout for pathological cases of
   440 higher-order unification.
   441 
   442 
   443 *** Document preparation ***
   444 
   445 * Antiquotation @{lemma} now imitates a regular terminal proof,
   446 demanding keyword 'by' and supporting the full method expression
   447 syntax just like the Isar command 'by'.
   448 
   449 
   450 *** HOL ***
   451 
   452 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   453 points Main and Complex_Main remain as before.
   454 
   455 * Logic image HOL-Plain provides a minimal HOL with the most important
   456 tools available (inductive, datatype, primrec, ...).  This facilitates
   457 experimentation and tool development.  Note that user applications
   458 (and library theories) should never refer to anything below theory
   459 Main, as before.
   460 
   461 * Logic image HOL-Main stops at theory Main, and thus facilitates
   462 experimentation due to shorter build times.
   463 
   464 * Logic image HOL-NSA contains theories of nonstandard analysis which
   465 were previously part of former HOL-Complex.  Entry point Hyperreal
   466 remains valid, but theories formerly using Complex_Main should now use
   467 new entry point Hypercomplex.
   468 
   469 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   470 Posix processes.  Avoids potentially expensive forking of the ML
   471 process.  New thread-based implementation also works on non-Unix
   472 platforms (Cygwin).  Provers are no longer hardwired, but defined
   473 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   474 commands are covered in the isar-ref manual.
   475 
   476 * Wrapper scripts for remote SystemOnTPTP service allows to use
   477 sledgehammer without local ATP installation (Vampire etc.). Other
   478 provers may be included via suitable ML wrappers, see also
   479 src/HOL/ATP_Linkup.thy.
   480 
   481 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   482 menu.
   483 
   484 * The metis method no longer fails because the theorem is too trivial
   485 (contains the empty clause).
   486 
   487 * The metis method now fails in the usual manner, rather than raising
   488 an exception, if it determines that it cannot prove the theorem.
   489 
   490 * Method "coherent" implements a prover for coherent logic (see also
   491 src/Tools/coherent.ML).
   492 
   493 * Constants "undefined" and "default" replace "arbitrary".  Usually
   494 "undefined" is the right choice to replace "arbitrary", though
   495 logically there is no difference.  INCOMPATIBILITY.
   496 
   497 * Command "value" now integrates different evaluation mechanisms.  The
   498 result of the first successful evaluation mechanism is printed.  In
   499 square brackets a particular named evaluation mechanisms may be
   500 specified (currently, [SML], [code] or [nbe]).  See further
   501 src/HOL/ex/Eval_Examples.thy.
   502 
   503 * Normalization by evaluation now allows non-leftlinear equations.
   504 Declare with attribute [code nbe].
   505 
   506 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   507 as the structured Isar versions "cases" and "induct", cf. the
   508 corresponding "cases" and "induct" attributes.  Mutual induction rules
   509 are now presented as a list of individual projections
   510 (e.g. foo_bar.inducts for types foo and bar); the old format with
   511 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   512 rare situations a different rule is selected --- notably nested tuple
   513 elimination instead of former prod.exhaust: use explicit (case_tac t
   514 rule: prod.exhaust) here.
   515 
   516 * Attributes "cases", "induct", "coinduct" support "del" option.
   517 
   518 * Removed fact "case_split_thm", which duplicates "case_split".
   519 
   520 * The option datatype has been moved to a new theory Option.  Renamed
   521 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   522 
   523 * New predicate "strict_mono" classifies strict functions on partial
   524 orders.  With strict functions on linear orders, reasoning about
   525 (in)equalities is facilitated by theorems "strict_mono_eq",
   526 "strict_mono_less_eq" and "strict_mono_less".
   527 
   528 * Some set operations are now proper qualified constants with
   529 authentic syntax.  INCOMPATIBILITY:
   530 
   531     op Int ~>   Set.Int
   532     op Un ~>    Set.Un
   533     INTER ~>    Set.INTER
   534     UNION ~>    Set.UNION
   535     Inter ~>    Set.Inter
   536     Union ~>    Set.Union
   537     {} ~>       Set.empty
   538     UNIV ~>     Set.UNIV
   539 
   540 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   541 theory Set.
   542 
   543 * Auxiliary class "itself" has disappeared -- classes without any
   544 parameter are treated as expected by the 'class' command.
   545 
   546 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   547 
   548 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   549 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   550 
   551 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   552 method "approximation".  It proves formulas on real values by using
   553 interval arithmetic.  In the formulas are also the transcendental
   554 functions sin, cos, tan, atan, ln, exp and the constant pi are
   555 allowed. For examples see
   556 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   557 
   558 * Theory "Reflection" now resides in HOL/Library.
   559 
   560 * Entry point to Word library now simply named "Word".
   561 INCOMPATIBILITY.
   562 
   563 * Made source layout more coherent with logical distribution
   564 structure:
   565 
   566     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   567     src/HOL/Library/Code_Message.thy ~> src/HOL/
   568     src/HOL/Library/GCD.thy ~> src/HOL/
   569     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   570     src/HOL/Library/Parity.thy ~> src/HOL/
   571     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   572     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   573     src/HOL/Real/Lubs.thy ~> src/HOL/
   574     src/HOL/Real/PReal.thy ~> src/HOL/
   575     src/HOL/Real/Rational.thy ~> src/HOL/
   576     src/HOL/Real/RComplete.thy ~> src/HOL/
   577     src/HOL/Real/RealDef.thy ~> src/HOL/
   578     src/HOL/Real/RealPow.thy ~> src/HOL/
   579     src/HOL/Real/Real.thy ~> src/HOL/
   580     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   581     src/HOL/Complex/Complex.thy ~> src/HOL/
   582     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   583     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   584     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   585     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   586     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   587     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   588     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   589     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   590     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   591     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   592     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   593     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   594     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   595     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   596     src/HOL/Real/Float ~> src/HOL/Library/
   597     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   598     src/HOL/Real/RealVector.thy ~> src/HOL/
   599 
   600     src/HOL/arith_data.ML ~> src/HOL/Tools
   601     src/HOL/hologic.ML ~> src/HOL/Tools
   602     src/HOL/simpdata.ML ~> src/HOL/Tools
   603     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   604     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   605     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   606     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   607     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   608     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   609     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   610 
   611     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   612     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   613     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   614     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   615     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   616     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   617 
   618 * If methods "eval" and "evaluation" encounter a structured proof
   619 state with !!/==>, only the conclusion is evaluated to True (if
   620 possible), avoiding strange error messages.
   621 
   622 * Method "sizechange" automates termination proofs using (a
   623 modification of) the size-change principle.  Requires SAT solver.  See
   624 src/HOL/ex/Termination.thy for examples.
   625 
   626 * Simplifier: simproc for let expressions now unfolds if bound
   627 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   628 
   629 * Method "arith": Linear arithmetic now ignores all inequalities when
   630 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   631 
   632 * New attribute "arith" for facts that should always be used
   633 automatically by arithmetic. It is intended to be used locally in
   634 proofs, e.g.
   635 
   636   assumes [arith]: "x > 0"
   637 
   638 Global usage is discouraged because of possible performance impact.
   639 
   640 * New classes "top" and "bot" with corresponding operations "top" and
   641 "bot" in theory Orderings; instantiation of class "complete_lattice"
   642 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   643 
   644 * Changed definition lemma "less_fun_def" in order to provide an
   645 instance for preorders on functions; use lemma "less_le" instead.
   646 INCOMPATIBILITY.
   647 
   648 * Theory Orderings: class "wellorder" moved here, with explicit
   649 induction rule "less_induct" as assumption.  For instantiation of
   650 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   651 INCOMPATIBILITY.
   652 
   653 * Theory Orderings: added class "preorder" as superclass of "order".
   654 INCOMPATIBILITY: Instantiation proofs for order, linorder
   655 etc. slightly changed.  Some theorems named order_class.* now named
   656 preorder_class.*.
   657 
   658 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   659 "diag" to "Id_on".
   660 
   661 * Theory Finite_Set: added a new fold combinator of type
   662 
   663   ('a => 'b => 'b) => 'b => 'a set => 'b
   664 
   665 Occasionally this is more convenient than the old fold combinator
   666 which is now defined in terms of the new one and renamed to
   667 fold_image.
   668 
   669 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   670 and "ring_simps" have been replaced by "algebra_simps" (which can be
   671 extended with further lemmas!).  At the moment both still exist but
   672 the former will disappear at some point.
   673 
   674 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   675 class recpower.  Type-specific simp rules for various recpower types
   676 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   677 
   678 rat_power_0    -> power_0
   679 rat_power_Suc  -> power_Suc
   680 realpow_0      -> power_0
   681 realpow_Suc    -> power_Suc
   682 complexpow_0   -> power_0
   683 complexpow_Suc -> power_Suc
   684 power_poly_0   -> power_0
   685 power_poly_Suc -> power_Suc
   686 
   687 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   688 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   689 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   690 of lemmas from Divides has been generalized from nat to class
   691 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   692 renames resulting from duplicate elimination:
   693 
   694     dvd_def_mod ~>          dvd_eq_mod_eq_0
   695     zero_dvd_iff ~>         dvd_0_left_iff
   696     dvd_0 ~>                dvd_0_right
   697     DIVISION_BY_ZERO_DIV ~> div_by_0
   698     DIVISION_BY_ZERO_MOD ~> mod_by_0
   699     mult_div ~>             div_mult_self2_is_id
   700     mult_mod ~>             mod_mult_self2_is_0
   701 
   702 * Theory IntDiv: removed many lemmas that are instances of class-based
   703 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   704 rename old lemmas as follows:
   705 
   706 dvd_diff               -> nat_dvd_diff
   707 dvd_zminus_iff         -> dvd_minus_iff
   708 mod_add1_eq            -> mod_add_eq
   709 mod_mult1_eq           -> mod_mult_right_eq
   710 mod_mult1_eq'          -> mod_mult_left_eq
   711 mod_mult_distrib_mod   -> mod_mult_eq
   712 nat_mod_add_left_eq    -> mod_add_left_eq
   713 nat_mod_add_right_eq   -> mod_add_right_eq
   714 nat_mod_div_trivial    -> mod_div_trivial
   715 nat_mod_mod_trivial    -> mod_mod_trivial
   716 zdiv_zadd_self1        -> div_add_self1
   717 zdiv_zadd_self2        -> div_add_self2
   718 zdiv_zmult_self1       -> div_mult_self2_is_id
   719 zdiv_zmult_self2       -> div_mult_self1_is_id
   720 zdvd_triv_left         -> dvd_triv_left
   721 zdvd_triv_right        -> dvd_triv_right
   722 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   723 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   724 zmod_zadd_left_eq      -> mod_add_left_eq
   725 zmod_zadd_right_eq     -> mod_add_right_eq
   726 zmod_zadd_self1        -> mod_add_self1
   727 zmod_zadd_self2        -> mod_add_self2
   728 zmod_zadd1_eq          -> mod_add_eq
   729 zmod_zdiff1_eq         -> mod_diff_eq
   730 zmod_zdvd_zmod         -> mod_mod_cancel
   731 zmod_zmod_cancel       -> mod_mod_cancel
   732 zmod_zmult_self1       -> mod_mult_self2_is_0
   733 zmod_zmult_self2       -> mod_mult_self1_is_0
   734 zmod_1                 -> mod_by_1
   735 zdiv_1                 -> div_by_1
   736 zdvd_abs1              -> abs_dvd_iff
   737 zdvd_abs2              -> dvd_abs_iff
   738 zdvd_refl              -> dvd_refl
   739 zdvd_trans             -> dvd_trans
   740 zdvd_zadd              -> dvd_add
   741 zdvd_zdiff             -> dvd_diff
   742 zdvd_zminus_iff        -> dvd_minus_iff
   743 zdvd_zminus2_iff       -> minus_dvd_iff
   744 zdvd_zmultD            -> dvd_mult_right
   745 zdvd_zmultD2           -> dvd_mult_left
   746 zdvd_zmult_mono        -> mult_dvd_mono
   747 zdvd_0_right           -> dvd_0_right
   748 zdvd_0_left            -> dvd_0_left_iff
   749 zdvd_1_left            -> one_dvd
   750 zminus_dvd_iff         -> minus_dvd_iff
   751 
   752 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   753 
   754 * The real numbers offer decimal input syntax: 12.34 is translated
   755 into 1234/10^2. This translation is not reversed upon output.
   756 
   757 * Theory Library/Polynomial defines an abstract type 'a poly of
   758 univariate polynomials with coefficients of type 'a.  In addition to
   759 the standard ring operations, it also supports div and mod.  Code
   760 generation is also supported, using list-style constructors.
   761 
   762 * Theory Library/Inner_Product defines a class of real_inner for real
   763 inner product spaces, with an overloaded operation inner :: 'a => 'a
   764 => real.  Class real_inner is a subclass of real_normed_vector from
   765 theory RealVector.
   766 
   767 * Theory Library/Product_Vector provides instances for the product
   768 type 'a * 'b of several classes from RealVector and Inner_Product.
   769 Definitions of addition, subtraction, scalar multiplication, norms,
   770 and inner products are included.
   771 
   772 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   773 addition to the field operations, numerals and case syntax are also
   774 supported.
   775 
   776 * Theory Library/Diagonalize provides constructive version of Cantor's
   777 first diagonalization argument.
   778 
   779 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   780 zlcm (for int); carried together from various gcd/lcm developements in
   781 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   782 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   783 may recover tupled syntax as follows:
   784 
   785     hide (open) const gcd
   786     abbreviation gcd where
   787       "gcd == (%(a, b). GCD.gcd a b)"
   788     notation (output)
   789       GCD.gcd ("gcd '(_, _')")
   790 
   791 The same works for lcm, zgcd, zlcm.
   792 
   793 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   794 instantiations for algebraic structures.  Removed some duplicate
   795 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   796 
   797 * ML antiquotation @{code} takes a constant as argument and generates
   798 corresponding code in background and inserts name of the corresponding
   799 resulting ML value/function/datatype constructor binding in place.
   800 All occurrences of @{code} with a single ML block are generated
   801 simultaneously.  Provides a generic and safe interface for
   802 instrumentalizing code generation.  See
   803 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   804 In future you ought to refrain from ad-hoc compiling generated SML
   805 code on the ML toplevel.  Note that (for technical reasons) @{code}
   806 cannot refer to constants for which user-defined serializations are
   807 set.  Refer to the corresponding ML counterpart directly in that
   808 cases.
   809 
   810 * Command 'rep_datatype': instead of theorem names the command now
   811 takes a list of terms denoting the constructors of the type to be
   812 represented as datatype.  The characteristic theorems have to be
   813 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   814 have disappeared in favour of existing ones:
   815 
   816     unit_induct                 ~> unit.induct
   817     prod_induct                 ~> prod.induct
   818     sum_induct                  ~> sum.induct
   819     Suc_Suc_eq                  ~> nat.inject
   820     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   821 
   822 
   823 *** HOL-Algebra ***
   824 
   825 * New locales for orders and lattices where the equivalence relation
   826 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   827 locales use a record structure with field eq for the equivalence.
   828 
   829 * New theory of factorial domains.
   830 
   831 * Units_l_inv and Units_r_inv are now simp rules by default.
   832 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   833 and/or r_inv will now also require deletion of these lemmas.
   834 
   835 * Renamed the following theorems, INCOMPATIBILITY:
   836 
   837 UpperD ~> Upper_memD
   838 LowerD ~> Lower_memD
   839 least_carrier ~> least_closed
   840 greatest_carrier ~> greatest_closed
   841 greatest_Lower_above ~> greatest_Lower_below
   842 one_zero ~> carrier_one_zero
   843 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   844 
   845 
   846 *** HOL-Nominal ***
   847 
   848 * Nominal datatypes can now contain type-variables.
   849 
   850 * Commands 'nominal_inductive' and 'equivariance' work with local
   851 theory targets.
   852 
   853 * Nominal primrec can now works with local theory targets and its
   854 specification syntax now conforms to the general format as seen in
   855 'inductive' etc.
   856 
   857 * Method "perm_simp" honours the standard simplifier attributes
   858 (no_asm), (no_asm_use) etc.
   859 
   860 * The new predicate #* is defined like freshness, except that on the
   861 left hand side can be a set or list of atoms.
   862 
   863 * Experimental command 'nominal_inductive2' derives strong induction
   864 principles for inductive definitions.  In contrast to
   865 'nominal_inductive', which can only deal with a fixed number of
   866 binders, it can deal with arbitrary expressions standing for sets of
   867 atoms to be avoided.  The only inductive definition we have at the
   868 moment that needs this generalisation is the typing rule for Lets in
   869 the algorithm W:
   870 
   871  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   872  -----------------------------------------------------------------
   873          Gamma |- Let x be t1 in t2 : T2
   874 
   875 In this rule one wants to avoid all the binders that are introduced by
   876 "close Gamma T1".  We are looking for other examples where this
   877 feature might be useful.  Please let us know.
   878 
   879 
   880 *** HOLCF ***
   881 
   882 * Reimplemented the simplification procedure for proving continuity
   883 subgoals.  The new simproc is extensible; users can declare additional
   884 continuity introduction rules with the attribute [cont2cont].
   885 
   886 * The continuity simproc now uses a different introduction rule for
   887 solving continuity subgoals on terms with lambda abstractions.  In
   888 some rare cases the new simproc may fail to solve subgoals that the
   889 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   890 Potential INCOMPATIBILITY.
   891 
   892 * Command 'fixrec': specification syntax now conforms to the general
   893 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   894 examples.  INCOMPATIBILITY.
   895 
   896 
   897 *** ZF ***
   898 
   899 * Proof of Zorn's Lemma for partial orders.
   900 
   901 
   902 *** ML ***
   903 
   904 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   905 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   906 depends on multithreading, so timouts will not work before Poly/ML
   907 5.2.1!
   908 
   909 * High-level support for concurrent ML programming, see
   910 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   911 particularly convenient to organize independent functional
   912 computations.  The concept of "synchronized variables" provides a
   913 higher-order interface for components with shared state, avoiding the
   914 delicate details of mutexes and condition variables.  (Requires
   915 Poly/ML 5.2.1 or later.)
   916 
   917 * ML bindings produced via Isar commands are stored within the Isar
   918 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   919 become thread-safe and work with undo as expected (concerning
   920 top-level bindings, not side-effects on global references).
   921 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   922 compiler at runtime; really global bindings need to be given outside a
   923 theory.  (Requires Poly/ML 5.2 or later.)
   924 
   925 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   926 context.  Top-level ML bindings are stored within the proof context in
   927 a purely sequential fashion, disregarding the nested proof structure.
   928 ML bindings introduced by 'ML_prf' are discarded at the end of the
   929 proof.  (Requires Poly/ML 5.2 or later.)
   930 
   931 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   932 and Method.setup, as well as Isar commands 'attribute_setup' and
   933 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   934 existing code accordingly, or use plain 'setup' together with old
   935 Method.add_method.
   936 
   937 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   938 to 'a -> thm, while results are always tagged with an authentic oracle
   939 name.  The Isar command 'oracle' is now polymorphic, no argument type
   940 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   941 accordingly.  Note that extra performance may be gained by producing
   942 the cterm carefully, avoiding slow Thm.cterm_of.
   943 
   944 * Simplified interface for defining document antiquotations via
   945 ThyOutput.antiquotation, ThyOutput.output, and optionally
   946 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
   947 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
   948 examples.
   949 
   950 * More systematic treatment of long names, abstract name bindings, and
   951 name space operations.  Basic operations on qualified names have been
   952 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
   953 Long_Name.append.  Old type bstring has been mostly replaced by
   954 abstract type binding (see structure Binding), which supports precise
   955 qualification by packages and local theory targets, as well as proper
   956 tracking of source positions.  INCOMPATIBILITY, need to wrap old
   957 bstring values into Binding.name, or better pass through abstract
   958 bindings everywhere.  See further src/Pure/General/long_name.ML,
   959 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
   960 
   961 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
   962 LocalTheory.note etc.) now refer to the *full* internal name, not the
   963 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
   964 
   965 * Disposed old type and term read functions (Sign.read_def_typ,
   966 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
   967 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
   968 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
   969 Syntax.read_term_global etc.; see also OldGoals.read_term as last
   970 resort for legacy applications.
   971 
   972 * Disposed old declarations, tactics, tactic combinators that refer to
   973 the simpset or claset of an implicit theory (such as Addsimps,
   974 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
   975 embedded ML text, or local_simpset_of with a proper context passed as
   976 explicit runtime argument.
   977 
   978 * Rules and tactics that read instantiations (read_instantiate,
   979 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
   980 context, which is required for parsing and type-checking.  Moreover,
   981 the variables are specified as plain indexnames, not string encodings
   982 thereof.  INCOMPATIBILITY.
   983 
   984 * Generic Toplevel.add_hook interface allows to analyze the result of
   985 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
   986 for theorem dependency output of transactions resulting in a new
   987 theory state.
   988 
   989 * ML antiquotations: block-structured compilation context indicated by
   990 \<lbrace> ... \<rbrace>; additional antiquotation forms:
   991 
   992   @{binding name}                         - basic name binding
   993   @{let ?pat = term}                      - term abbreviation (HO matching)
   994   @{note name = fact}                     - fact abbreviation
   995   @{thm fact}                             - singleton fact (with attributes)
   996   @{thms fact}                            - general fact (with attributes)
   997   @{lemma prop by method}                 - singleton goal
   998   @{lemma prop by meth1 meth2}            - singleton goal
   999   @{lemma prop1 ... propN by method}      - general goal
  1000   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1001   @{lemma (open) ...}                     - open derivation
  1002 
  1003 
  1004 *** System ***
  1005 
  1006 * The Isabelle "emacs" tool provides a specific interface to invoke
  1007 Proof General / Emacs, with more explicit failure if that is not
  1008 installed (the old isabelle-interface script silently falls back on
  1009 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1010 installation location of the Proof General distribution.
  1011 
  1012 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1013 the Isabelle process into a JVM/Scala application.  See
  1014 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1015 process wrapper has been discontinued.)
  1016 
  1017 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1018 
  1019 * Various status messages (with exact source position information) are
  1020 emitted, if proper markup print mode is enabled.  This allows
  1021 user-interface components to provide detailed feedback on internal
  1022 prover operations.
  1023 
  1024 
  1025 
  1026 New in Isabelle2008 (June 2008)
  1027 -------------------------------
  1028 
  1029 *** General ***
  1030 
  1031 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1032 and updated, with formally checked references as hyperlinks.
  1033 
  1034 * Theory loader: use_thy (and similar operations) no longer set the
  1035 implicit ML context, which was occasionally hard to predict and in
  1036 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1037 provides a proper context already.
  1038 
  1039 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1040 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1041 'use' within a theory file will do the job.
  1042 
  1043 * Name space merge now observes canonical order, i.e. the second space
  1044 is inserted into the first one, while existing entries in the first
  1045 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1046 swap theory imports.
  1047 
  1048 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1049 INCOMPATIBILITY in identifier syntax etc.
  1050 
  1051 * Outer syntax: string tokens no longer admit escaped white space,
  1052 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1053 white space without escapes.
  1054 
  1055 * Outer syntax: string tokens may contain arbitrary character codes
  1056 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1057 "foo_bar".
  1058 
  1059 
  1060 *** Pure ***
  1061 
  1062 * Context-dependent token translations.  Default setup reverts locally
  1063 fixed variables, and adds hilite markup for undeclared frees.
  1064 
  1065 * Unused theorems can be found using the new command 'unused_thms'.
  1066 There are three ways of invoking it:
  1067 
  1068 (1) unused_thms
  1069      Only finds unused theorems in the current theory.
  1070 
  1071 (2) unused_thms thy_1 ... thy_n -
  1072      Finds unused theorems in the current theory and all of its ancestors,
  1073      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1074 
  1075 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1076      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1077      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1078      their ancestors.
  1079 
  1080 In order to increase the readability of the list produced by
  1081 unused_thms, theorems that have been created by a particular instance
  1082 of a theory command such as 'inductive' or 'function' are considered
  1083 to belong to the same "group", meaning that if at least one theorem in
  1084 this group is used, the other theorems in the same group are no longer
  1085 reported as unused.  Moreover, if all theorems in the group are
  1086 unused, only one theorem in the group is displayed.
  1087 
  1088 Note that proof objects have to be switched on in order for
  1089 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1090 usually the case when using Proof General with the default settings).
  1091 
  1092 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1093 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1094 duplicate fact bindings, or even accidental fact duplications.  Note
  1095 that tools may maintain dynamically scoped facts systematically, using
  1096 PureThy.add_thms_dynamic.
  1097 
  1098 * Command 'hide' now allows to hide from "fact" name space as well.
  1099 
  1100 * Eliminated destructive theorem database, simpset, claset, and
  1101 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1102 update of theories within ML code.
  1103 
  1104 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1105 INCOMPATIBILITY, object-logics depending on former Pure require
  1106 additional setup PureThy.old_appl_syntax_setup; object-logics
  1107 depending on former CPure need to refer to Pure.
  1108 
  1109 * Commands 'use' and 'ML' are now purely functional, operating on
  1110 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1111 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1112 INCOMPATIBILITY.
  1113 
  1114 * Command 'setup': discontinued implicit version with ML reference.
  1115 
  1116 * Instantiation target allows for simultaneous specification of class
  1117 instance operations together with an instantiation proof.
  1118 Type-checking phase allows to refer to class operations uniformly.
  1119 See src/HOL/Complex/Complex.thy for an Isar example and
  1120 src/HOL/Library/Eval.thy for an ML example.
  1121 
  1122 * Indexing of literal facts: be more serious about including only
  1123 facts from the visible specification/proof context, but not the
  1124 background context (locale etc.).  Affects `prop` notation and method
  1125 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1126 situations.
  1127 
  1128 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1129 "(open)" option, which used to expose internal bound variables to the
  1130 proof text.
  1131 
  1132 * Isar statements: removed obsolete case "rule_context".
  1133 INCOMPATIBILITY, better use explicit fixes/assumes.
  1134 
  1135 * Locale proofs: default proof step now includes 'unfold_locales';
  1136 hence 'proof' without argument may be used to unfold locale
  1137 predicates.
  1138 
  1139 
  1140 *** Document preparation ***
  1141 
  1142 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1143 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1144 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1145 spot); renamed link color from "darkblue" to "linkcolor" (default
  1146 value unchanged, can be redefined via \definecolor); no longer sets
  1147 "a4paper" option (unnecessary or even intrusive).
  1148 
  1149 * Antiquotation @{lemma A method} proves proposition A by the given
  1150 method (either a method name or a method name plus (optional) method
  1151 arguments in parentheses) and prints A just like @{prop A}.
  1152 
  1153 
  1154 *** HOL ***
  1155 
  1156 * New primrec package.  Specification syntax conforms in style to
  1157 definition/function/....  No separate induction rule is provided.  The
  1158 "primrec" command distinguishes old-style and new-style specifications
  1159 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1160 When adjusting theories, beware: constants stemming from new-style
  1161 primrec specifications have authentic syntax.
  1162 
  1163 * Metis prover is now an order of magnitude faster, and also works
  1164 with multithreading.
  1165 
  1166 * Metis: the maximum number of clauses that can be produced from a
  1167 theorem is now given by the attribute max_clauses.  Theorems that
  1168 exceed this number are ignored, with a warning printed.
  1169 
  1170 * Sledgehammer no longer produces structured proofs by default. To
  1171 enable, declare [[sledgehammer_full = true]].  Attributes
  1172 reconstruction_modulus, reconstruction_sorts renamed
  1173 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1174 
  1175 * Method "induct_scheme" derives user-specified induction rules
  1176 from well-founded induction and completeness of patterns. This factors
  1177 out some operations that are done internally by the function package
  1178 and makes them available separately.  See
  1179 src/HOL/ex/Induction_Scheme.thy for examples.
  1180 
  1181 * More flexible generation of measure functions for termination
  1182 proofs: Measure functions can be declared by proving a rule of the
  1183 form "is_measure f" and giving it the [measure_function] attribute.
  1184 The "is_measure" predicate is logically meaningless (always true), and
  1185 just guides the heuristic.  To find suitable measure functions, the
  1186 termination prover sets up the goal "is_measure ?f" of the appropriate
  1187 type and generates all solutions by prolog-style backwards proof using
  1188 the declared rules.
  1189 
  1190 This setup also deals with rules like 
  1191 
  1192   "is_measure f ==> is_measure (list_size f)"
  1193 
  1194 which accommodates nested datatypes that recurse through lists.
  1195 Similar rules are predeclared for products and option types.
  1196 
  1197 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1198 
  1199   INCOMPATIBILITIES:
  1200 
  1201   - Definitions of overloaded constants on sets have to be replaced by
  1202     definitions on => and bool.
  1203 
  1204   - Some definitions of overloaded operators on sets can now be proved
  1205     using the definitions of the operators on => and bool.  Therefore,
  1206     the following theorems have been renamed:
  1207 
  1208       subset_def   -> subset_eq
  1209       psubset_def  -> psubset_eq
  1210       set_diff_def -> set_diff_eq
  1211       Compl_def    -> Compl_eq
  1212       Sup_set_def  -> Sup_set_eq
  1213       Inf_set_def  -> Inf_set_eq
  1214       sup_set_def  -> sup_set_eq
  1215       inf_set_def  -> inf_set_eq
  1216 
  1217   - Due to the incompleteness of the HO unification algorithm, some
  1218     rules such as subst may require manual instantiation, if some of
  1219     the unknowns in the rule is a set.
  1220 
  1221   - Higher order unification and forward proofs:
  1222     The proof pattern
  1223 
  1224       have "P (S::'a set)" <...>
  1225       then have "EX S. P S" ..
  1226 
  1227     no longer works (due to the incompleteness of the HO unification
  1228     algorithm) and must be replaced by the pattern
  1229 
  1230       have "EX S. P S"
  1231       proof
  1232         show "P S" <...>
  1233       qed
  1234 
  1235   - Calculational reasoning with subst (or similar rules):
  1236     The proof pattern
  1237 
  1238       have "P (S::'a set)" <...>
  1239       also have "S = T" <...>
  1240       finally have "P T" .
  1241 
  1242     no longer works (for similar reasons as the previous example) and
  1243     must be replaced by something like
  1244 
  1245       have "P (S::'a set)" <...>
  1246       moreover have "S = T" <...>
  1247       ultimately have "P T" by simp
  1248 
  1249   - Tactics or packages written in ML code:
  1250     Code performing pattern matching on types via
  1251 
  1252       Type ("set", [T]) => ...
  1253 
  1254     must be rewritten. Moreover, functions like strip_type or
  1255     binder_types no longer return the right value when applied to a
  1256     type of the form
  1257 
  1258       T1 => ... => Tn => U => bool
  1259 
  1260     rather than
  1261 
  1262       T1 => ... => Tn => U set
  1263 
  1264 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1265 Wellfounded_Relations to theory Wellfounded.
  1266 
  1267 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1268 
  1269 * Class finite no longer treats UNIV as class parameter.  Use class
  1270 enum from theory Library/Enum instead to achieve a similar effect.
  1271 INCOMPATIBILITY.
  1272 
  1273 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1274 and "Cons".  INCOMPATIBILITY.
  1275 
  1276 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1277 Potential INCOMPATIBILITY.
  1278 
  1279 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1280 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1281 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1282 
  1283 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1284 the same name in theory Orderings:
  1285 
  1286   less_trans
  1287   less_linear
  1288   le_imp_less_or_eq
  1289   le_less_trans
  1290   less_le_trans
  1291   less_not_sym
  1292   less_asym
  1293 
  1294 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1295 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1296 and different variable names.
  1297 
  1298 * Library/Option_ord.thy: Canonical order on option type.
  1299 
  1300 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1301 finite maps.
  1302 
  1303 * Library/Countable.thy: Type class for countable types.
  1304 
  1305 * Theory Int: The representation of numerals has changed.  The infix
  1306 operator BIT and the bit datatype with constructors B0 and B1 have
  1307 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1308 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1309 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1310 accordingly.
  1311 
  1312 * Theory Nat: definition of <= and < on natural numbers no longer
  1313 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1314 le_def and less_def have disappeared.  Consider lemmas not_less
  1315 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1316 
  1317 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1318 (whose purpose mainly is for various fold_set functionals) have been
  1319 abandoned in favor of the existing algebraic classes
  1320 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1321 lower_semilattice (resp. upper_semilattice) and linorder.
  1322 INCOMPATIBILITY.
  1323 
  1324 * Theory Transitive_Closure: induct and cases rules now declare proper
  1325 case_names ("base" and "step").  INCOMPATIBILITY.
  1326 
  1327 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1328 lattices.  The form set-specific version is available as
  1329 Inductive.lfp_ordinal_induct_set.
  1330 
  1331 * Renamed theorems "power.simps" to "power_int.simps".
  1332 INCOMPATIBILITY.
  1333 
  1334 * Class semiring_div provides basic abstract properties of semirings
  1335 with division and modulo operations.  Subsumes former class dvd_mod.
  1336 
  1337 * Merged theories IntDef, Numeral and IntArith into unified theory
  1338 Int.  INCOMPATIBILITY.
  1339 
  1340 * Theory Library/Code_Index: type "index" now represents natural
  1341 numbers rather than integers.  INCOMPATIBILITY.
  1342 
  1343 * New class "uminus" with operation "uminus" (split of from class
  1344 "minus" which now only has operation "minus", binary).
  1345 INCOMPATIBILITY.
  1346 
  1347 * Constants "card", "internal_split", "option_map" now with authentic
  1348 syntax.  INCOMPATIBILITY.
  1349 
  1350 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1351 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1352 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1353 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1354 Sup_set_def, le_def, less_def, option_map_def now with object
  1355 equality.  INCOMPATIBILITY.
  1356 
  1357 * Records. Removed K_record, and replaced it by pure lambda term
  1358 %x. c. The simplifier setup is now more robust against eta expansion.
  1359 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1360 
  1361 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1362 
  1363 * Library/ListVector: new theory of arithmetic vector operations.
  1364 
  1365 * Library/Order_Relation: new theory of various orderings as sets of
  1366 pairs.  Defines preorders, partial orders, linear orders and
  1367 well-orders on sets and on types.
  1368 
  1369 
  1370 *** ZF ***
  1371 
  1372 * Renamed some theories to allow to loading both ZF and HOL in the
  1373 same session:
  1374 
  1375   Datatype  -> Datatype_ZF
  1376   Inductive -> Inductive_ZF
  1377   Int       -> Int_ZF
  1378   IntDiv    -> IntDiv_ZF
  1379   Nat       -> Nat_ZF
  1380   List      -> List_ZF
  1381   Main      -> Main_ZF
  1382 
  1383 INCOMPATIBILITY: ZF theories that import individual theories below
  1384 Main might need to be adapted.  Regular theory Main is still
  1385 available, as trivial extension of Main_ZF.
  1386 
  1387 
  1388 *** ML ***
  1389 
  1390 * ML within Isar: antiquotation @{const name} or @{const
  1391 name(typargs)} produces statically-checked Const term.
  1392 
  1393 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1394 (of the same name).  Removed obsolete print command.
  1395 
  1396 * Removed obsolete "use_legacy_bindings" function.
  1397 
  1398 * The ``print mode'' is now a thread-local value derived from a global
  1399 template (the former print_mode reference), thus access becomes
  1400 non-critical.  The global print_mode reference is for session
  1401 management only; user-code should use print_mode_value,
  1402 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1403 
  1404 * Functions system/system_out provide a robust way to invoke external
  1405 shell commands, with propagation of interrupts (requires Poly/ML
  1406 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1407 
  1408 
  1409 *** System ***
  1410 
  1411 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1412 in accordance with Proof General 3.7, which prefers GNU emacs.
  1413 
  1414 * isatool tty runs Isabelle process with plain tty interaction;
  1415 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1416 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1417 
  1418 * isatool browser now works with Cygwin as well, using general
  1419 "javapath" function defined in Isabelle process environment.
  1420 
  1421 * YXML notation provides a simple and efficient alternative to
  1422 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1423 isatool yxml as described in the Isabelle system manual.
  1424 
  1425 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1426 provides general wrapper for managing an Isabelle process in a robust
  1427 fashion, with ``cooked'' output from stdin/stderr.
  1428 
  1429 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1430 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1431 
  1432 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1433 way of changing the user's settings is via
  1434 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1435 script.
  1436 
  1437 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1438 cores of the underlying machine, which is a good starting point for
  1439 optimal performance tuning.  The corresponding usedir option -M allows
  1440 "max" as an alias for "0".  WARNING: does not work on certain versions
  1441 of Mac OS (with Poly/ML 5.1).
  1442 
  1443 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1444 adverse effect of Isabelle flooding interactive front-ends (notably
  1445 ProofGeneral / XEmacs).
  1446 
  1447 
  1448 
  1449 New in Isabelle2007 (November 2007)
  1450 -----------------------------------
  1451 
  1452 *** General ***
  1453 
  1454 * More uniform information about legacy features, notably a
  1455 warning/error of "Legacy feature: ...", depending on the state of the
  1456 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1457 legacy features will disappear eventually.
  1458 
  1459 * Theory syntax: the header format ``theory A = B + C:'' has been
  1460 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1461 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1462 
  1463 * Theory syntax: the old non-Isar theory file format has been
  1464 discontinued altogether.  Note that ML proof scripts may still be used
  1465 with Isar theories; migration is usually quite simple with the ML
  1466 function use_legacy_bindings.  INCOMPATIBILITY.
  1467 
  1468 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1469 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1470 quotes.
  1471 
  1472 * Theory loader: be more serious about observing the static theory
  1473 header specifications (including optional directories), but not the
  1474 accidental file locations of previously successful loads.  The strict
  1475 update policy of former update_thy is now already performed by
  1476 use_thy, so the former has been removed; use_thys updates several
  1477 theories simultaneously, just as 'imports' within a theory header
  1478 specification, but without merging the results.  Potential
  1479 INCOMPATIBILITY: may need to refine theory headers and commands
  1480 ROOT.ML which depend on load order.
  1481 
  1482 * Theory loader: optional support for content-based file
  1483 identification, instead of the traditional scheme of full physical
  1484 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1485 (cf. the system manual).  The new scheme allows to work with
  1486 non-finished theories in persistent session images, such that source
  1487 files may be moved later on without requiring reloads.
  1488 
  1489 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1490 file (with the same base name as the theory) are considered a legacy
  1491 feature, which will disappear eventually. Even now, the theory loader
  1492 no longer maintains dependencies on such files.
  1493 
  1494 * Syntax: the scope for resolving ambiguities via type-inference is
  1495 now limited to individual terms, instead of whole simultaneous
  1496 specifications as before. This greatly reduces the complexity of the
  1497 syntax module and improves flexibility by separating parsing and
  1498 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1499 'fixes' etc.) are required in rare situations.
  1500 
  1501 * Syntax: constants introduced by new-style packages ('definition',
  1502 'abbreviation' etc.) are passed through the syntax module in
  1503 ``authentic mode''. This means that associated mixfix annotations
  1504 really stick to such constants, independently of potential name space
  1505 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1506 trees are represented slightly differently, may need to adapt syntax
  1507 translations accordingly. Use CONST marker in 'translations' and
  1508 @{const_syntax} antiquotation in 'parse_translation' etc.
  1509 
  1510 * Legacy goal package: reduced interface to the bare minimum required
  1511 to keep existing proof scripts running.  Most other user-level
  1512 functions are now part of the OldGoals structure, which is *not* open
  1513 by default (consider isatool expandshort before open OldGoals).
  1514 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1515 these tend to cause confusion about the actual goal (!) context being
  1516 used here, which is not necessarily the same as the_context().
  1517 
  1518 * Command 'find_theorems': supports "*" wild-card in "name:"
  1519 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1520 support a specific search form (see ProofGeneral/CHANGES).
  1521 
  1522 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1523 by default, which means that "prems" (and also "fixed variables") are
  1524 suppressed from proof state output.  Note that the ProofGeneral
  1525 settings mechanism allows to change and save options persistently, but
  1526 older versions of Isabelle will fail to start up if a negative prems
  1527 limit is imposed.
  1528 
  1529 * Local theory targets may be specified by non-nested blocks of
  1530 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1531 contain definitions, theorems etc., including any derived mechanism
  1532 that has been implemented on top of these primitives.  This concept
  1533 generalizes the existing ``theorem (in ...)'' towards more versatility
  1534 and scalability.
  1535 
  1536 * Proof General interface: proper undo of final 'end' command;
  1537 discontinued Isabelle/classic mode (ML proof scripts).
  1538 
  1539 
  1540 *** Document preparation ***
  1541 
  1542 * Added antiquotation @{theory name} which prints the given name,
  1543 after checking that it refers to a valid ancestor theory in the
  1544 current context.
  1545 
  1546 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1547 check the given source text as ML type/structure, printing verbatim.
  1548 
  1549 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1550 "c args == rhs" given in the current context.  (Any number of
  1551 arguments may be given on the LHS.)
  1552 
  1553 
  1554 *** Pure ***
  1555 
  1556 * The 'class' package offers a combination of axclass and locale to
  1557 achieve Haskell-like type classes in Isabelle.  Definitions and
  1558 theorems within a class context produce both relative results (with
  1559 implicit parameters according to the locale context), and polymorphic
  1560 constants with qualified polymorphism (according to the class
  1561 context).  Within the body context of a 'class' target, a separate
  1562 syntax layer ("user space type system") takes care of converting
  1563 between global polymorphic consts and internal locale representation.
  1564 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1565 "isatool doc classes" provides a tutorial.
  1566 
  1567 * Generic code generator framework allows to generate executable
  1568 code for ML and Haskell (including Isabelle classes).  A short usage
  1569 sketch:
  1570 
  1571     internal compilation:
  1572         export_code <list of constants (term syntax)> in SML
  1573     writing SML code to a file:
  1574         export_code <list of constants (term syntax)> in SML <filename>
  1575     writing OCaml code to a file:
  1576         export_code <list of constants (term syntax)> in OCaml <filename>
  1577     writing Haskell code to a bunch of files:
  1578         export_code <list of constants (term syntax)> in Haskell <filename>
  1579 
  1580     evaluating closed propositions to True/False using code generation:
  1581         method ``eval''
  1582 
  1583 Reasonable default setup of framework in HOL.
  1584 
  1585 Theorem attributs for selecting and transforming function equations theorems:
  1586 
  1587     [code fun]:        select a theorem as function equation for a specific constant
  1588     [code fun del]:    deselect a theorem as function equation for a specific constant
  1589     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1590     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1591 
  1592 User-defined serializations (target in {SML, OCaml, Haskell}):
  1593 
  1594     code_const <and-list of constants (term syntax)>
  1595       {(target) <and-list of const target syntax>}+
  1596 
  1597     code_type <and-list of type constructors>
  1598       {(target) <and-list of type target syntax>}+
  1599 
  1600     code_instance <and-list of instances>
  1601       {(target)}+
  1602         where instance ::= <type constructor> :: <class>
  1603 
  1604     code_class <and_list of classes>
  1605       {(target) <and-list of class target syntax>}+
  1606         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1607 
  1608 code_instance and code_class only are effective to target Haskell.
  1609 
  1610 For example usage see src/HOL/ex/Codegenerator.thy and
  1611 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1612 generation from Isabelle/HOL theories is available via "isatool doc
  1613 codegen".
  1614 
  1615 * Code generator: consts in 'consts_code' Isar commands are now
  1616 referred to by usual term syntax (including optional type
  1617 annotations).
  1618 
  1619 * Command 'no_translations' removes translation rules from theory
  1620 syntax.
  1621 
  1622 * Overloaded definitions are now actually checked for acyclic
  1623 dependencies.  The overloading scheme is slightly more general than
  1624 that of Haskell98, although Isabelle does not demand an exact
  1625 correspondence to type class and instance declarations.
  1626 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1627 exotic versions of overloading -- at the discretion of the user!
  1628 
  1629 Polymorphic constants are represented via type arguments, i.e. the
  1630 instantiation that matches an instance against the most general
  1631 declaration given in the signature.  For example, with the declaration
  1632 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1633 as c(nat).  Overloading is essentially simultaneous structural
  1634 recursion over such type arguments.  Incomplete specification patterns
  1635 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1636 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1637 Command 'print_theory' outputs the normalized system of recursive
  1638 equations, see section "definitions".
  1639 
  1640 * Configuration options are maintained within the theory or proof
  1641 context (with name and type bool/int/string), providing a very simple
  1642 interface to a poor-man's version of general context data.  Tools may
  1643 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1644 these values using Config.get etc.  Users may change options via an
  1645 associated attribute of the same name.  This form of context
  1646 declaration works particularly well with commands 'declare' or
  1647 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1648 very easy to avoid global references, which would not observe Isar
  1649 toplevel undo/redo and fail to work with multithreading.
  1650 
  1651 Various global ML references of Pure and HOL have been turned into
  1652 configuration options:
  1653 
  1654   Unify.search_bound		unify_search_bound
  1655   Unify.trace_bound		unify_trace_bound
  1656   Unify.trace_simp		unify_trace_simp
  1657   Unify.trace_types		unify_trace_types
  1658   Simplifier.simp_depth_limit	simp_depth_limit
  1659   Blast.depth_limit		blast_depth_limit
  1660   DatatypeProp.dtK		datatype_distinctness_limit
  1661   fast_arith_neq_limit  	fast_arith_neq_limit
  1662   fast_arith_split_limit	fast_arith_split_limit
  1663 
  1664 * Named collections of theorems may be easily installed as context
  1665 data using the functor NamedThmsFun (see also
  1666 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1667 attributes; there is also a toplevel print command.  This facility is
  1668 just a common case of general context data, which is the preferred way
  1669 for anything more complex than just a list of facts in canonical
  1670 order.
  1671 
  1672 * Isar: command 'declaration' augments a local theory by generic
  1673 declaration functions written in ML.  This enables arbitrary content
  1674 being added to the context, depending on a morphism that tells the
  1675 difference of the original declaration context wrt. the application
  1676 context encountered later on.
  1677 
  1678 * Isar: proper interfaces for simplification procedures.  Command
  1679 'simproc_setup' declares named simprocs (with match patterns, and body
  1680 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1681 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1682 
  1683 * Isar: an extra pair of brackets around attribute declarations
  1684 abbreviates a theorem reference involving an internal dummy fact,
  1685 which will be ignored later --- only the effect of the attribute on
  1686 the background context will persist.  This form of in-place
  1687 declarations is particularly useful with commands like 'declare' and
  1688 'using', for example ``have A using [[simproc a]] by simp''.
  1689 
  1690 * Isar: method "assumption" (and implicit closing of subproofs) now
  1691 takes simple non-atomic goal assumptions into account: after applying
  1692 an assumption as a rule the resulting subgoals are solved by atomic
  1693 assumption steps.  This is particularly useful to finish 'obtain'
  1694 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1695 without referring to the original premise "!!x. P x ==> thesis" in the
  1696 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1697 more permissive.
  1698 
  1699 * Isar: implicit use of prems from the Isar proof context is
  1700 considered a legacy feature.  Common applications like ``have A .''
  1701 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1702 referencing facts explicitly here improves readability and
  1703 maintainability of proof texts.
  1704 
  1705 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1706 the obtained context from the course of reasoning!  For example:
  1707 
  1708   assume "EX x y. A x & B y"   -- "any previous fact"
  1709   then guess x and y by clarify
  1710 
  1711 This technique is potentially adventurous, depending on the facts and
  1712 proof tools being involved here.
  1713 
  1714 * Isar: known facts from the proof context may be specified as literal
  1715 propositions, using ASCII back-quote syntax.  This works wherever
  1716 named facts used to be allowed so far, in proof commands, proof
  1717 methods, attributes etc.  Literal facts are retrieved from the context
  1718 according to unification of type and term parameters.  For example,
  1719 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1720 theorems in the current context, then these are valid literal facts:
  1721 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1722 
  1723 There is also a proof method "fact" which does the same composition
  1724 for explicit goal states, e.g. the following proof texts coincide with
  1725 certain special cases of literal facts:
  1726 
  1727   have "A" by fact                 ==  note `A`
  1728   have "A ==> B" by fact           ==  note `A ==> B`
  1729   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1730   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1731 
  1732 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1733 outer syntax.  Thus symbolic identifiers may be used without
  1734 additional white space in declarations like this: ``assume *: A''.
  1735 
  1736 * Isar: 'print_facts' prints all local facts of the current context,
  1737 both named and unnamed ones.
  1738 
  1739 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1740 
  1741   def x == "t" and y == "u"
  1742 
  1743 * Isar: added command 'unfolding', which is structurally similar to
  1744 'using', but affects both the goal state and facts by unfolding given
  1745 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1746 'unfolded' attribute may be replaced by first-class proof text.
  1747 
  1748 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1749 and command 'unfolding' now all support object-level equalities
  1750 (potentially conditional).  The underlying notion of rewrite rule is
  1751 analogous to the 'rule_format' attribute, but *not* that of the
  1752 Simplifier (which is usually more generous).
  1753 
  1754 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1755 premises of a theorem by n. Useful in conjunction with drule.
  1756 
  1757 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1758 method expression within a sandbox consisting of the first N
  1759 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1760 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1761 simplifies all new goals that emerge from applying rule foo to the
  1762 originally first one.
  1763 
  1764 * Isar: schematic goals are no longer restricted to higher-order
  1765 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1766 expected.
  1767 
  1768 * Isar: the conclusion of a long theorem statement is now either
  1769 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1770 (essentially a disjunction of cases with local parameters and
  1771 assumptions).  The latter allows to express general elimination rules
  1772 adequately; in this notation common elimination rules look like this:
  1773 
  1774   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1775     assumes "EX x. P x"
  1776     obtains x where "P x"
  1777 
  1778   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1779     assumes "A & B"
  1780     obtains A and B
  1781 
  1782   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1783     assumes "A | B"
  1784     obtains
  1785       A
  1786     | B
  1787 
  1788 The subsequent classical rules even refer to the formal "thesis"
  1789 explicitly:
  1790 
  1791   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1792     obtains "~ thesis"
  1793 
  1794   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1795     obtains "thesis ==> something"
  1796 
  1797 The actual proof of an 'obtains' statement is analogous to that of the
  1798 Isar proof element 'obtain', only that there may be several cases.
  1799 Optional case names may be specified in parentheses; these will be
  1800 available both in the present proof and as annotations in the
  1801 resulting rule, for later use with the 'cases' method (cf. attribute
  1802 case_names).
  1803 
  1804 * Isar: the assumptions of a long theorem statement are available as
  1805 "assms" fact in the proof context.  This is more appropriate than the
  1806 (historical) "prems", which refers to all assumptions of the current
  1807 context, including those from the target locale, proof body etc.
  1808 
  1809 * Isar: 'print_statement' prints theorems from the current theory or
  1810 proof context in long statement form, according to the syntax of a
  1811 top-level lemma.
  1812 
  1813 * Isar: 'obtain' takes an optional case name for the local context
  1814 introduction rule (default "that").
  1815 
  1816 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1817 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1818 to occur.
  1819 
  1820 * Pure: syntax "CONST name" produces a fully internalized constant
  1821 according to the current context.  This is particularly useful for
  1822 syntax translations that should refer to internal constant
  1823 representations independently of name spaces.
  1824 
  1825 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1826 instead of "FOO ". This allows multiple binder declarations to coexist
  1827 in the same context.  INCOMPATIBILITY.
  1828 
  1829 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1830 primitive that also works in a locale context (both for constants and
  1831 fixed variables). Type declaration and internal syntactic representation
  1832 of given constants retrieved from the context. Likewise, the
  1833 'no_notation' command allows to remove given syntax annotations from the
  1834 current context.
  1835 
  1836 * Isar/locales: new derived specification elements 'axiomatization',
  1837 'definition', 'abbreviation', which support type-inference, admit
  1838 object-level specifications (equality, equivalence).  See also the
  1839 isar-ref manual.  Examples:
  1840 
  1841   axiomatization
  1842     eq  (infix "===" 50) where
  1843     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1844 
  1845   definition "f x y = x + y + 1"
  1846   definition g where "g x = f x x"
  1847 
  1848   abbreviation
  1849     neq  (infix "=!=" 50) where
  1850     "x =!= y == ~ (x === y)"
  1851 
  1852 These specifications may be also used in a locale context.  Then the
  1853 constants being introduced depend on certain fixed parameters, and the
  1854 constant name is qualified by the locale base name.  An internal
  1855 abbreviation takes care for convenient input and output, making the
  1856 parameters implicit and using the original short name.  See also
  1857 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1858 entities from a monomorphic theory.
  1859 
  1860 Presently, abbreviations are only available 'in' a target locale, but
  1861 not inherited by general import expressions.  Also note that
  1862 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1863 'translations' in common applications.  The "no_abbrevs" print mode
  1864 prevents folding of abbreviations in term output.
  1865 
  1866 Concrete syntax is attached to specified constants in internal form,
  1867 independently of name spaces.  The parse tree representation is
  1868 slightly different -- use 'notation' instead of raw 'syntax', and
  1869 'translations' with explicit "CONST" markup to accommodate this.
  1870 
  1871 * Pure/Isar: unified syntax for new-style specification mechanisms
  1872 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1873 full type inference and dummy patterns ("_").  For example:
  1874 
  1875   definition "K x _ = x"
  1876 
  1877   inductive conj for A B
  1878   where "A ==> B ==> conj A B"
  1879 
  1880 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1881 the current context.  Print mode "no_abbrevs" prevents inversion of
  1882 abbreviations on output.
  1883 
  1884 * Isar/locales: improved parameter handling: use of locales "var" and
  1885 "struct" no longer necessary; - parameter renamings are no longer
  1886 required to be injective.  For example, this allows to define
  1887 endomorphisms as locale endom = homom mult mult h.
  1888 
  1889 * Isar/locales: changed the way locales with predicates are defined.
  1890 Instead of accumulating the specification, the imported expression is
  1891 now an interpretation.  INCOMPATIBILITY: different normal form of
  1892 locale expressions.  In particular, in interpretations of locales with
  1893 predicates, goals repesenting already interpreted fragments are not
  1894 removed automatically.  Use methods `intro_locales' and
  1895 `unfold_locales'; see below.
  1896 
  1897 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1898 provide backward reasoning on locales predicates.  The methods are
  1899 aware of interpretations and discharge corresponding goals.
  1900 `intro_locales' is less aggressive then `unfold_locales' and does not
  1901 unfold predicates to assumptions.
  1902 
  1903 * Isar/locales: the order in which locale fragments are accumulated
  1904 has changed.  This enables to override declarations from fragments due
  1905 to interpretations -- for example, unwanted simp rules.
  1906 
  1907 * Isar/locales: interpretation in theories and proof contexts has been
  1908 extended.  One may now specify (and prove) equations, which are
  1909 unfolded in interpreted theorems.  This is useful for replacing
  1910 defined concepts (constants depending on locale parameters) by
  1911 concepts already existing in the target context.  Example:
  1912 
  1913   interpretation partial_order ["op <= :: [int, int] => bool"]
  1914     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1915 
  1916 Typically, the constant `partial_order.less' is created by a
  1917 definition specification element in the context of locale
  1918 partial_order.
  1919 
  1920 * Method "induct": improved internal context management to support
  1921 local fixes and defines on-the-fly. Thus explicit meta-level
  1922 connectives !!  and ==> are rarely required anymore in inductive goals
  1923 (using object-logic connectives for this purpose has been long
  1924 obsolete anyway). Common proof patterns are explained in
  1925 src/HOL/Induct/Common_Patterns.thy, see also
  1926 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1927 examples.
  1928 
  1929 * Method "induct": improved handling of simultaneous goals. Instead of
  1930 introducing object-level conjunction, the statement is now split into
  1931 several conclusions, while the corresponding symbolic cases are nested
  1932 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1933 see src/HOL/Induct/Common_Patterns.thy, for example.
  1934 
  1935 * Method "induct": mutual induction rules are now specified as a list
  1936 of rule sharing the same induction cases. HOL packages usually provide
  1937 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1938 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1939 mutual induction rules differently, i.e. like this:
  1940 
  1941   (induct rule: foo_bar.inducts)
  1942   (induct set: foo bar)
  1943   (induct pred: foo bar)
  1944   (induct type: foo bar)
  1945 
  1946 The ML function ProjectRule.projections turns old-style rules into the
  1947 new format.
  1948 
  1949 * Method "coinduct": dual of induction, see
  1950 src/HOL/Library/Coinductive_List.thy for various examples.
  1951 
  1952 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  1953 considered a legacy feature.
  1954 
  1955 * Attribute "symmetric" produces result with standardized schematic
  1956 variables (index 0).  Potential INCOMPATIBILITY.
  1957 
  1958 * Simplifier: by default the simplifier trace only shows top level
  1959 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  1960 default. Thus there is less danger of being flooded by the trace. The
  1961 trace indicates where parts have been suppressed.
  1962   
  1963 * Provers/classical: removed obsolete classical version of elim_format
  1964 attribute; classical elim/dest rules are now treated uniformly when
  1965 manipulating the claset.
  1966 
  1967 * Provers/classical: stricter checks to ensure that supplied intro,
  1968 dest and elim rules are well-formed; dest and elim rules must have at
  1969 least one premise.
  1970 
  1971 * Provers/classical: attributes dest/elim/intro take an optional
  1972 weight argument for the rule (just as the Pure versions).  Weights are
  1973 ignored by automated tools, but determine the search order of single
  1974 rule steps.
  1975 
  1976 * Syntax: input syntax now supports dummy variable binding "%_. b",
  1977 where the body does not mention the bound variable.  Note that dummy
  1978 patterns implicitly depend on their context of bounds, which makes
  1979 "{_. _}" match any set comprehension as expected.  Potential
  1980 INCOMPATIBILITY -- parse translations need to cope with syntactic
  1981 constant "_idtdummy" in the binding position.
  1982 
  1983 * Syntax: removed obsolete syntactic constant "_K" and its associated
  1984 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  1985 for example "A -> B" => "Pi A (%_. B)".
  1986 
  1987 * Pure: 'class_deps' command visualizes the subclass relation, using
  1988 the graph browser tool.
  1989 
  1990 * Pure: 'print_theory' now suppresses certain internal declarations by
  1991 default; use '!' option for full details.
  1992 
  1993 
  1994 *** HOL ***
  1995 
  1996 * Method "metis" proves goals by applying the Metis general-purpose
  1997 resolution prover (see also http://gilith.com/software/metis/).
  1998 Examples are in the directory MetisExamples.  WARNING: the
  1999 Isabelle/HOL-Metis integration does not yet work properly with
  2000 multi-threading.
  2001   
  2002 * Command 'sledgehammer' invokes external automatic theorem provers as
  2003 background processes.  It generates calls to the "metis" method if
  2004 successful. These can be pasted into the proof.  Users do not have to
  2005 wait for the automatic provers to return.  WARNING: does not really
  2006 work with multi-threading.
  2007 
  2008 * New "auto_quickcheck" feature tests outermost goal statements for
  2009 potential counter-examples.  Controlled by ML references
  2010 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2011 5000 milliseconds).  Fails silently if statements is outside of
  2012 executable fragment, or any other codgenerator problem occurs.
  2013 
  2014 * New constant "undefined" with axiom "undefined x = undefined".
  2015 
  2016 * Added class "HOL.eq", allowing for code generation with polymorphic
  2017 equality.
  2018 
  2019 * Some renaming of class constants due to canonical name prefixing in
  2020 the new 'class' package:
  2021 
  2022     HOL.abs ~> HOL.abs_class.abs
  2023     HOL.divide ~> HOL.divide_class.divide
  2024     0 ~> HOL.zero_class.zero
  2025     1 ~> HOL.one_class.one
  2026     op + ~> HOL.plus_class.plus
  2027     op - ~> HOL.minus_class.minus
  2028     uminus ~> HOL.minus_class.uminus
  2029     op * ~> HOL.times_class.times
  2030     op < ~> HOL.ord_class.less
  2031     op <= > HOL.ord_class.less_eq
  2032     Nat.power ~> Power.power_class.power
  2033     Nat.size ~> Nat.size_class.size
  2034     Numeral.number_of ~> Numeral.number_class.number_of
  2035     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2036     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2037     Orderings.min ~> Orderings.ord_class.min
  2038     Orderings.max ~> Orderings.ord_class.max
  2039     Divides.op div ~> Divides.div_class.div
  2040     Divides.op mod ~> Divides.div_class.mod
  2041     Divides.op dvd ~> Divides.div_class.dvd
  2042 
  2043 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2044 
  2045 a) User-defined constants using any of the names "plus", "minus",
  2046 "times", "less" or "less_eq". The standard syntax translations for
  2047 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2048 names.
  2049 
  2050 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2051 INCOMPATIBILITY: use more specific names.
  2052 
  2053 c) Permutative equations (e.g. "a + b = b + a")
  2054 Since the change of names also changes the order of terms, permutative
  2055 rewrite rules may get applied in a different order. Experience shows
  2056 that this is rarely the case (only two adaptions in the whole Isabelle
  2057 distribution).  INCOMPATIBILITY: rewrite proofs
  2058 
  2059 d) ML code directly refering to constant names
  2060 This in general only affects hand-written proof tactics, simprocs and
  2061 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2062 Consider using @{const_name} antiquotation.
  2063 
  2064 * New class "default" with associated constant "default".
  2065 
  2066 * Function "sgn" is now overloaded and available on int, real, complex
  2067 (and other numeric types), using class "sgn".  Two possible defs of
  2068 sgn are given as equational assumptions in the classes sgn_if and
  2069 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2070 INCOMPATIBILITY.
  2071 
  2072 * Locale "partial_order" now unified with class "order" (cf. theory
  2073 Orderings), added parameter "less".  INCOMPATIBILITY.
  2074 
  2075 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2076 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2077 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2078 
  2079 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2080 changed order of proof goals in instance proofs.
  2081 
  2082 * The transitivity reasoner for partial and linear orders is set up
  2083 for classes "order" and "linorder".  Instances of the reasoner are available
  2084 in all contexts importing or interpreting the corresponding locales.
  2085 Method "order" invokes the reasoner separately; the reasoner
  2086 is also integrated with the Simplifier as a solver.  Diagnostic
  2087 command 'print_orders' shows the available instances of the reasoner
  2088 in the current context.
  2089 
  2090 * Localized monotonicity predicate in theory "Orderings"; integrated
  2091 lemmas max_of_mono and min_of_mono with this predicate.
  2092 INCOMPATIBILITY.
  2093 
  2094 * Formulation of theorem "dense" changed slightly due to integration
  2095 with new class dense_linear_order.
  2096 
  2097 * Uniform lattice theory development in HOL.
  2098 
  2099     constants "meet" and "join" now named "inf" and "sup"
  2100     constant "Meet" now named "Inf"
  2101 
  2102     classes "meet_semilorder" and "join_semilorder" now named
  2103       "lower_semilattice" and "upper_semilattice"
  2104     class "lorder" now named "lattice"
  2105     class "comp_lat" now named "complete_lattice"
  2106 
  2107     Instantiation of lattice classes allows explicit definitions
  2108     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2109 
  2110   INCOMPATIBILITY.  Theorem renames:
  2111 
  2112     meet_left_le            ~> inf_le1
  2113     meet_right_le           ~> inf_le2
  2114     join_left_le            ~> sup_ge1
  2115     join_right_le           ~> sup_ge2
  2116     meet_join_le            ~> inf_sup_ord
  2117     le_meetI                ~> le_infI
  2118     join_leI                ~> le_supI
  2119     le_meet                 ~> le_inf_iff
  2120     le_join                 ~> ge_sup_conv
  2121     meet_idempotent         ~> inf_idem
  2122     join_idempotent         ~> sup_idem
  2123     meet_comm               ~> inf_commute
  2124     join_comm               ~> sup_commute
  2125     meet_leI1               ~> le_infI1
  2126     meet_leI2               ~> le_infI2
  2127     le_joinI1               ~> le_supI1
  2128     le_joinI2               ~> le_supI2
  2129     meet_assoc              ~> inf_assoc
  2130     join_assoc              ~> sup_assoc
  2131     meet_left_comm          ~> inf_left_commute
  2132     meet_left_idempotent    ~> inf_left_idem
  2133     join_left_comm          ~> sup_left_commute
  2134     join_left_idempotent    ~> sup_left_idem
  2135     meet_aci                ~> inf_aci
  2136     join_aci                ~> sup_aci
  2137     le_def_meet             ~> le_iff_inf
  2138     le_def_join             ~> le_iff_sup
  2139     join_absorp2            ~> sup_absorb2
  2140     join_absorp1            ~> sup_absorb1
  2141     meet_absorp1            ~> inf_absorb1
  2142     meet_absorp2            ~> inf_absorb2
  2143     meet_join_absorp        ~> inf_sup_absorb
  2144     join_meet_absorp        ~> sup_inf_absorb
  2145     distrib_join_le         ~> distrib_sup_le
  2146     distrib_meet_le         ~> distrib_inf_le
  2147 
  2148     add_meet_distrib_left   ~> add_inf_distrib_left
  2149     add_join_distrib_left   ~> add_sup_distrib_left
  2150     is_join_neg_meet        ~> is_join_neg_inf
  2151     is_meet_neg_join        ~> is_meet_neg_sup
  2152     add_meet_distrib_right  ~> add_inf_distrib_right
  2153     add_join_distrib_right  ~> add_sup_distrib_right
  2154     add_meet_join_distribs  ~> add_sup_inf_distribs
  2155     join_eq_neg_meet        ~> sup_eq_neg_inf
  2156     meet_eq_neg_join        ~> inf_eq_neg_sup
  2157     add_eq_meet_join        ~> add_eq_inf_sup
  2158     meet_0_imp_0            ~> inf_0_imp_0
  2159     join_0_imp_0            ~> sup_0_imp_0
  2160     meet_0_eq_0             ~> inf_0_eq_0
  2161     join_0_eq_0             ~> sup_0_eq_0
  2162     neg_meet_eq_join        ~> neg_inf_eq_sup
  2163     neg_join_eq_meet        ~> neg_sup_eq_inf
  2164     join_eq_if              ~> sup_eq_if
  2165 
  2166     mono_meet               ~> mono_inf
  2167     mono_join               ~> mono_sup
  2168     meet_bool_eq            ~> inf_bool_eq
  2169     join_bool_eq            ~> sup_bool_eq
  2170     meet_fun_eq             ~> inf_fun_eq
  2171     join_fun_eq             ~> sup_fun_eq
  2172     meet_set_eq             ~> inf_set_eq
  2173     join_set_eq             ~> sup_set_eq
  2174     meet1_iff               ~> inf1_iff
  2175     meet2_iff               ~> inf2_iff
  2176     meet1I                  ~> inf1I
  2177     meet2I                  ~> inf2I
  2178     meet1D1                 ~> inf1D1
  2179     meet2D1                 ~> inf2D1
  2180     meet1D2                 ~> inf1D2
  2181     meet2D2                 ~> inf2D2
  2182     meet1E                  ~> inf1E
  2183     meet2E                  ~> inf2E
  2184     join1_iff               ~> sup1_iff
  2185     join2_iff               ~> sup2_iff
  2186     join1I1                 ~> sup1I1
  2187     join2I1                 ~> sup2I1
  2188     join1I1                 ~> sup1I1
  2189     join2I2                 ~> sup1I2
  2190     join1CI                 ~> sup1CI
  2191     join2CI                 ~> sup2CI
  2192     join1E                  ~> sup1E
  2193     join2E                  ~> sup2E
  2194 
  2195     is_meet_Meet            ~> is_meet_Inf
  2196     Meet_bool_def           ~> Inf_bool_def
  2197     Meet_fun_def            ~> Inf_fun_def
  2198     Meet_greatest           ~> Inf_greatest
  2199     Meet_lower              ~> Inf_lower
  2200     Meet_set_def            ~> Inf_set_def
  2201 
  2202     Sup_def                 ~> Sup_Inf
  2203     Sup_bool_eq             ~> Sup_bool_def
  2204     Sup_fun_eq              ~> Sup_fun_def
  2205     Sup_set_eq              ~> Sup_set_def
  2206 
  2207     listsp_meetI            ~> listsp_infI
  2208     listsp_meet_eq          ~> listsp_inf_eq
  2209 
  2210     meet_min                ~> inf_min
  2211     join_max                ~> sup_max
  2212 
  2213 * Added syntactic class "size"; overloaded constant "size" now has
  2214 type "'a::size ==> bool"
  2215 
  2216 * Internal reorganisation of `size' of datatypes: size theorems
  2217 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2218 simplification rules by default!); theorems "prod.size" now named
  2219 "*.size".
  2220 
  2221 * Class "div" now inherits from class "times" rather than "type".
  2222 INCOMPATIBILITY.
  2223 
  2224 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2225 Linorder etc.  have disappeared; operations defined in terms of
  2226 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2227 
  2228 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2229 
  2230 * HOL-Word: New extensive library and type for generic, fixed size
  2231 machine words, with arithemtic, bit-wise, shifting and rotating
  2232 operations, reflection into int, nat, and bool lists, automation for
  2233 linear arithmetic (by automatic reflection into nat or int), including
  2234 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2235 arithmetic type classes, supporting automatic simplification of
  2236 numerals on all operations.
  2237 
  2238 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2239 
  2240 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2241 
  2242 * Code generator library theories:
  2243   - Code_Integer represents HOL integers by big integer literals in target
  2244     languages.
  2245   - Code_Char represents HOL characters by character literals in target
  2246     languages.
  2247   - Code_Char_chr like Code_Char, but also offers treatment of character
  2248     codes; includes Code_Integer.
  2249   - Executable_Set allows to generate code for finite sets using lists.
  2250   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2251     denominator).
  2252   - Executable_Real implements a subset of real numbers, namly those
  2253     representable by rational numbers.
  2254   - Efficient_Nat implements natural numbers by integers, which in general will
  2255     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2256     includes Code_Integer.
  2257   - Code_Index provides an additional datatype index which is mapped to
  2258     target-language built-in integers.
  2259   - Code_Message provides an additional datatype message_string which is isomorphic to
  2260     strings; messages are mapped to target-language strings.
  2261 
  2262 * New package for inductive predicates
  2263 
  2264   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2265 
  2266     inductive
  2267       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2268       for z_1 :: U_1 and ... and z_n :: U_m
  2269     where
  2270       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2271     | ...
  2272 
  2273   with full support for type-inference, rather than
  2274 
  2275     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2276 
  2277     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2278     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2279 
  2280     inductive "s z_1 ... z_m"
  2281     intros
  2282       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2283       ...
  2284 
  2285   For backward compatibility, there is a wrapper allowing inductive
  2286   sets to be defined with the new package via
  2287 
  2288     inductive_set
  2289       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2290       for z_1 :: U_1 and ... and z_n :: U_m
  2291     where
  2292       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2293     | ...
  2294 
  2295   or
  2296 
  2297     inductive_set
  2298       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2299       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2300       for z_1 :: U_1 and ... and z_n :: U_m
  2301     where
  2302       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2303     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2304     | ...
  2305 
  2306   if the additional syntax "p ..." is required.
  2307 
  2308   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2309   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2310 
  2311   INCOMPATIBILITIES:
  2312 
  2313   - Since declaration and definition of inductive sets or predicates
  2314     is no longer separated, abbreviations involving the newly
  2315     introduced sets or predicates must be specified together with the
  2316     introduction rules after the 'where' keyword (see above), rather
  2317     than before the actual inductive definition.
  2318 
  2319   - The variables in induction and elimination rules are now
  2320     quantified in the order of their occurrence in the introduction
  2321     rules, rather than in alphabetical order. Since this may break
  2322     some proofs, these proofs either have to be repaired, e.g. by
  2323     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2324     statements of the form
  2325 
  2326       case (rule_i a_i_1 ... a_i_{k_i})
  2327 
  2328     or the old order of quantification has to be restored by explicitly adding
  2329     meta-level quantifiers in the introduction rules, i.e.
  2330 
  2331       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2332 
  2333   - The format of the elimination rules is now
  2334 
  2335       p z_1 ... z_m x_1 ... x_n ==>
  2336         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2337         ==> ... ==> P
  2338 
  2339     for predicates and
  2340 
  2341       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2342         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2343         ==> ... ==> P
  2344 
  2345     for sets rather than
  2346 
  2347       x : s z_1 ... z_m ==>
  2348         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2349         ==> ... ==> P
  2350 
  2351     This may require terms in goals to be expanded to n-tuples
  2352     (e.g. using case_tac or simplification with the split_paired_all
  2353     rule) before the above elimination rule is applicable.
  2354 
  2355   - The elimination or case analysis rules for (mutually) inductive
  2356     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2357     list of rules "p_1_..._p_k.elims" is no longer available.
  2358 
  2359 * New package "function"/"fun" for general recursive functions,
  2360 supporting mutual and nested recursion, definitions in local contexts,
  2361 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2362 for small examples, and the separate tutorial on the function
  2363 package. The old recdef "package" is still available as before, but
  2364 users are encouraged to use the new package.
  2365 
  2366 * Method "lexicographic_order" automatically synthesizes termination
  2367 relations as lexicographic combinations of size measures. 
  2368 
  2369 * Case-expressions allow arbitrary constructor-patterns (including
  2370 "_") and take their order into account, like in functional
  2371 programming.  Internally, this is translated into nested
  2372 case-expressions; missing cases are added and mapped to the predefined
  2373 constant "undefined". In complicated cases printing may no longer show
  2374 the original input but the internal form. Lambda-abstractions allow
  2375 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2376 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2377 variable.
  2378 
  2379 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2380 is an abbreviation for "of_nat :: nat => int". The simplification
  2381 rules for "of_nat" have been changed to work like "int" did
  2382 previously.  Potential INCOMPATIBILITY:
  2383   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2384   - of_nat_diff and of_nat_mult are no longer default simp rules
  2385 
  2386 * Method "algebra" solves polynomial equations over (semi)rings using
  2387 Groebner bases. The (semi)ring structure is defined by locales and the
  2388 tool setup depends on that generic context. Installing the method for
  2389 a specific type involves instantiating the locale and possibly adding
  2390 declarations for computation on the coefficients.  The method is
  2391 already instantiated for natural numbers and for the axiomatic class
  2392 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2393 CALCULEMUS 2007 for the general principles underlying this
  2394 architecture of context-aware proof-tools.
  2395 
  2396 * Method "ferrack" implements quantifier elimination over
  2397 special-purpose dense linear orders using locales (analogous to
  2398 "algebra"). The method is already installed for class
  2399 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2400 rat, etc.
  2401 
  2402 * Former constant "List.op @" now named "List.append".  Use ML
  2403 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2404 circumvent possible incompatibilities when working on ML level.
  2405 
  2406 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2407 
  2408 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2409 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2410 
  2411 * New syntax for Haskell-like list comprehension (input only), eg.
  2412 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2413 
  2414 * The special syntax for function "filter" has changed from [x :
  2415 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2416 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2417 
  2418 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2419 defined on nat only, as an abbreviation for [a..<Suc b]
  2420 INCOMPATIBILITY.
  2421 
  2422 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2423 
  2424 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2425 
  2426 * New lemma collection field_simps (an extension of ring_simps) for
  2427 manipulating (in)equations involving division. Multiplies with all
  2428 denominators that can be proved to be non-zero (in equations) or
  2429 positive/negative (in inequations).
  2430 
  2431 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2432 have been improved and renamed to ring_simps, group_simps and
  2433 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2434 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2435 
  2436 * Theory Library/Commutative_Ring: switched from recdef to function
  2437 package; constants add, mul, pow now curried.  Infix syntax for
  2438 algebraic operations.
  2439 
  2440 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2441 INCOMPATIBILITY.
  2442 
  2443 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2444 INCOMPATIBILITY.
  2445 
  2446 * HOL/records: generalised field-update to take a function on the
  2447 field rather than the new value: r(|A := x|) is translated to A_update
  2448 (K x) r The K-combinator that is internally used is called K_record.
  2449 INCOMPATIBILITY: Usage of the plain update functions has to be
  2450 adapted.
  2451  
  2452 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2453 * x = 0, which are required for a semiring.  Richer structures do not
  2454 inherit from semiring_0 anymore, because this property is a theorem
  2455 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2456 there is more to prove, but this is mostly trivial.
  2457 
  2458 * Class "recpower" is generalized to arbitrary monoids, not just
  2459 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2460 commutativity or semiring properties additionally.
  2461 
  2462 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2463 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2464 better use 'abbreviation'.
  2465 
  2466 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2467 
  2468 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2469 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2470 significant changes for setting up numeral syntax for types:
  2471   - New constants Numeral.pred and Numeral.succ instead
  2472       of former Numeral.bin_pred and Numeral.bin_succ.
  2473   - Use integer operations instead of bin_add, bin_mult and so on.
  2474   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2475   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2476 
  2477 See src/HOL/Integ/IntArith.thy for an example setup.
  2478 
  2479 * Command 'normal_form' computes the normal form of a term that may
  2480 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2481 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2482 heavy-duty computations because the functions are compiled to ML
  2483 first.  Correspondingly, a method "normalization" is provided.  See
  2484 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2485 
  2486 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2487 25 like -->); output depends on the "iff" print_mode, the default is
  2488 "A = B" (with priority 50).
  2489 
  2490 * Relations less (<) and less_eq (<=) are also available on type bool.
  2491 Modified syntax to disallow nesting without explicit parentheses,
  2492 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2493 INCOMPATIBILITY.
  2494 
  2495 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2496 
  2497 * Relation composition operator "op O" now has precedence 75 and binds
  2498 stronger than union and intersection. INCOMPATIBILITY.
  2499 
  2500 * The old set interval syntax "{m..n(}" (and relatives) has been
  2501 removed.  Use "{m..<n}" (and relatives) instead.
  2502 
  2503 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2504 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2505 ``declare [[simproc del: neq]]''.
  2506 
  2507 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2508 True/False.
  2509 
  2510 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2511 
  2512 * Theorem setsum_mult renamed to setsum_right_distrib.
  2513 
  2514 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2515 ``rule'' method.
  2516 
  2517 * Reimplemented methods "sat" and "satx", with several improvements:
  2518 goals no longer need to be stated as "<prems> ==> False", equivalences
  2519 (i.e. "=" on type bool) are handled, variable names of the form
  2520 "lit_<n>" are no longer reserved, significant speedup.
  2521 
  2522 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2523 zChaff is still supported as well.
  2524 
  2525 * 'inductive' and 'datatype': provide projections of mutual rules,
  2526 bundled as foo_bar.inducts;
  2527 
  2528 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2529 Library.
  2530 
  2531 * Library: moved theory Accessible_Part to main HOL.
  2532 
  2533 * Library: added theory Coinductive_List of potentially infinite lists
  2534 as greatest fixed-point.
  2535 
  2536 * Library: added theory AssocList which implements (finite) maps as
  2537 association lists.
  2538 
  2539 * Method "evaluation" solves goals (i.e. a boolean expression)
  2540 efficiently by compiling it to ML.  The goal is "proved" (via an
  2541 oracle) if it evaluates to True.
  2542 
  2543 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2544 also when invoked by the simplifier.  This results in the Simplifier
  2545 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2546 Configuration option fast_arith_split_limit=0 recovers the old
  2547 behavior.
  2548 
  2549 * Support for hex (0x20) and binary (0b1001) numerals.
  2550 
  2551 * New method: reify eqs (t), where eqs are equations for an
  2552 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2553 parameter, computes a term s::'b and a list xs::'a list and proves the
  2554 theorem I xs s = t. This is also known as reification or quoting. The
  2555 resulting theorem is applied to the subgoal to substitute t with I xs
  2556 s.  If t is omitted, the subgoal itself is reified.
  2557 
  2558 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2559 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2560 where f is supposed to be a computable function (in the sense of code
  2561 generattion). The method uses reify to compute s and xs as above then
  2562 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2563 r and finally gets the theorem t = r, which is again applied to the
  2564 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2565 
  2566 * Reflection: Automatic reification now handels binding, an example is
  2567 available in src/HOL/ex/ReflectionEx.thy
  2568 
  2569 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2570 command 'statespace' that is similar to 'record', but introduces an
  2571 abstract specification based on the locale infrastructure instead of
  2572 HOL types.  This leads to extra flexibility in composing state spaces,
  2573 in particular multiple inheritance and renaming of components.
  2574 
  2575 
  2576 *** HOL-Complex ***
  2577 
  2578 * Hyperreal: Functions root and sqrt are now defined on negative real
  2579 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2580 Nonnegativity side conditions have been removed from many lemmas, so
  2581 that more subgoals may now be solved by simplification; potential
  2582 INCOMPATIBILITY.
  2583 
  2584 * Real: new type classes formalize real normed vector spaces and
  2585 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2586 and norm :: 'a => real.
  2587 
  2588 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2589 reals into other types. The overloaded constant Reals :: 'a set is now
  2590 defined as range of_real; potential INCOMPATIBILITY.
  2591 
  2592 * Real: proper support for ML code generation, including 'quickcheck'.
  2593 Reals are implemented as arbitrary precision rationals.
  2594 
  2595 * Hyperreal: Several constants that previously worked only for the
  2596 reals have been generalized, so they now work over arbitrary vector
  2597 spaces. Type annotations may need to be added in some cases; potential
  2598 INCOMPATIBILITY.
  2599 
  2600   Infinitesimal  :: ('a::real_normed_vector) star set
  2601   HFinite        :: ('a::real_normed_vector) star set
  2602   HInfinite      :: ('a::real_normed_vector) star set
  2603   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2604   monad          :: ('a::real_normed_vector) star => 'a star set
  2605   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2606   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2607   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2608   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2609   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2610   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2611   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2612   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2613   sgn            :: 'a::real_normed_vector => 'a
  2614   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2615 
  2616 * Complex: Some complex-specific constants are now abbreviations for
  2617 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2618 hnorm.  Other constants have been entirely removed in favor of the
  2619 polymorphic versions (INCOMPATIBILITY):
  2620 
  2621   approx        <-- capprox
  2622   HFinite       <-- CFinite
  2623   HInfinite     <-- CInfinite
  2624   Infinitesimal <-- CInfinitesimal
  2625   monad         <-- cmonad
  2626   galaxy        <-- cgalaxy
  2627   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2628   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2629   (ns)deriv     <-- (ns)cderiv
  2630 
  2631 
  2632 *** HOL-Algebra ***
  2633 
  2634 * Formalisation of ideals and the quotient construction over rings.
  2635 
  2636 * Order and lattice theory no longer based on records.
  2637 INCOMPATIBILITY.
  2638 
  2639 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2640 greatest_closed.  INCOMPATIBILITY.
  2641 
  2642 * Method algebra is now set up via an attribute.  For examples see
  2643 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2644 of algebraic structures.
  2645 
  2646 * Renamed theory CRing to Ring.
  2647 
  2648 
  2649 *** HOL-Nominal ***
  2650 
  2651 * Substantial, yet incomplete support for nominal datatypes (binding
  2652 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2653 src/HOL/Nominal/Examples.  Prospective users should consult
  2654 http://isabelle.in.tum.de/nominal/
  2655 
  2656 
  2657 *** ML ***
  2658 
  2659 * ML basics: just one true type int, which coincides with IntInf.int
  2660 (even on SML/NJ).
  2661 
  2662 * ML within Isar: antiquotations allow to embed statically-checked
  2663 formal entities in the source, referring to the context available at
  2664 compile-time.  For example:
  2665 
  2666 ML {* @{sort "{zero,one}"} *}
  2667 ML {* @{typ "'a => 'b"} *}
  2668 ML {* @{term "%x. x"} *}
  2669 ML {* @{prop "x == y"} *}
  2670 ML {* @{ctyp "'a => 'b"} *}
  2671 ML {* @{cterm "%x. x"} *}
  2672 ML {* @{cprop "x == y"} *}
  2673 ML {* @{thm asm_rl} *}
  2674 ML {* @{thms asm_rl} *}
  2675 ML {* @{type_name c} *}
  2676 ML {* @{type_syntax c} *}
  2677 ML {* @{const_name c} *}
  2678 ML {* @{const_syntax c} *}
  2679 ML {* @{context} *}
  2680 ML {* @{theory} *}
  2681 ML {* @{theory Pure} *}
  2682 ML {* @{theory_ref} *}
  2683 ML {* @{theory_ref Pure} *}
  2684 ML {* @{simpset} *}
  2685 ML {* @{claset} *}
  2686 ML {* @{clasimpset} *}
  2687 
  2688 The same works for sources being ``used'' within an Isar context.
  2689 
  2690 * ML in Isar: improved error reporting; extra verbosity with
  2691 ML_Context.trace enabled.
  2692 
  2693 * Pure/General/table.ML: the join operations now works via exceptions
  2694 DUP/SAME instead of type option. This is simpler in simple cases, and
  2695 admits slightly more efficient complex applications.
  2696 
  2697 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2698 use Context.generic instead of just theory.
  2699 
  2700 * Pure: datatype Context.generic joins theory/Proof.context and
  2701 provides some facilities for code that works in either kind of
  2702 context, notably GenericDataFun for uniform theory and proof data.
  2703 
  2704 * Pure: simplified internal attribute type, which is now always
  2705 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2706 local (Proof.context) attributes have been discontinued, while
  2707 minimizing code duplication. Thm.rule_attribute and
  2708 Thm.declaration_attribute build canonical attributes; see also structure
  2709 Context for further operations on Context.generic, notably
  2710 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2711 declarations and definitions.
  2712 
  2713 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2714 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2715 init only required for impure data. INCOMPATIBILITY: empty really need
  2716 to be empty (no dependencies on theory content!)
  2717 
  2718 * Pure/kernel: consts certification ignores sort constraints given in
  2719 signature declarations. (This information is not relevant to the
  2720 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2721 potential INCOMPATIBILITY.
  2722 
  2723 * Pure: axiomatic type classes are now purely definitional, with
  2724 explicit proofs of class axioms and super class relations performed
  2725 internally. See Pure/axclass.ML for the main internal interfaces --
  2726 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2727 AxClass.axiomatize_class/classrel/arity supersede
  2728 Sign.add_classes/classrel/arities.
  2729 
  2730 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2731 global/local versions on theory vs. Proof.context have been
  2732 discontinued; Attrib.syntax and Method.syntax have been adapted
  2733 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2734 attributes, methods, etc.
  2735 
  2736 * Pure: several functions of signature "... -> theory -> theory * ..."
  2737 have been reoriented to "... -> theory -> ... * theory" in order to
  2738 allow natural usage in combination with the ||>, ||>>, |-> and
  2739 fold_map combinators.
  2740 
  2741 * Pure: official theorem names (closed derivations) and additional
  2742 comments (tags) are now strictly separate.  Name hints -- which are
  2743 maintained as tags -- may be attached any time without affecting the
  2744 derivation.
  2745 
  2746 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2747 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2748 achieve the old behaviour.
  2749 
  2750 * Pure: the "Goal" constant is now called "prop", supporting a
  2751 slightly more general idea of ``protecting'' meta-level rule
  2752 statements.
  2753 
  2754 * Pure: Logic.(un)varify only works in a global context, which is now
  2755 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2756 Logic.legacy_(un)varify as temporary workaround.
  2757 
  2758 * Pure: structure Name provides scalable operations for generating
  2759 internal variable names, notably Name.variants etc.  This replaces
  2760 some popular functions from term.ML:
  2761 
  2762   Term.variant		->  Name.variant
  2763   Term.variantlist	->  Name.variant_list
  2764   Term.invent_names	->  Name.invent_list
  2765 
  2766 Note that low-level renaming rarely occurs in new code -- operations
  2767 from structure Variable are used instead (see below).
  2768 
  2769 * Pure: structure Variable provides fundamental operations for proper
  2770 treatment of fixed/schematic variables in a context.  For example,
  2771 Variable.import introduces fixes for schematics of given facts and
  2772 Variable.export reverses the effect (up to renaming) -- this replaces
  2773 various freeze_thaw operations.
  2774 
  2775 * Pure: structure Goal provides simple interfaces for
  2776 init/conclude/finish and tactical prove operations (replacing former
  2777 Tactic.prove).  Goal.prove is the canonical way to prove results
  2778 within a given context; Goal.prove_global is a degraded version for
  2779 theory level goals, including a global Drule.standard.  Note that
  2780 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2781 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2782 in a locale context).
  2783 
  2784 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2785 and type checking (Syntax.check_term etc.), with common combinations
  2786 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2787 which are considered legacy and await removal.
  2788 
  2789 * Pure/Syntax: generic interfaces for type unchecking
  2790 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2791 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2792 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2793 available for convenience, but refer to the very same operations using
  2794 a mere theory instead of a full context.
  2795 
  2796 * Isar: simplified treatment of user-level errors, using exception
  2797 ERROR of string uniformly.  Function error now merely raises ERROR,
  2798 without any side effect on output channels.  The Isar toplevel takes
  2799 care of proper display of ERROR exceptions.  ML code may use plain
  2800 handle/can/try; cat_error may be used to concatenate errors like this:
  2801 
  2802   ... handle ERROR msg => cat_error msg "..."
  2803 
  2804 Toplevel ML code (run directly or through the Isar toplevel) may be
  2805 embedded into the Isar toplevel with exception display/debug like
  2806 this:
  2807 
  2808   Isar.toplevel (fn () => ...)
  2809 
  2810 INCOMPATIBILITY, removed special transform_error facilities, removed
  2811 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2812 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2813 -- use plain ERROR instead.
  2814 
  2815 * Isar: theory setup now has type (theory -> theory), instead of a
  2816 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2817 
  2818 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2819 ProofContext.debug/verbose flags.
  2820 
  2821 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2822 theory before entering a proof state.  Transactions now always see a
  2823 quasi-functional intermediate checkpoint, both in interactive and
  2824 batch mode.
  2825 
  2826 * Isar: simplified interfaces for outer syntax.  Renamed
  2827 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2828 OuterSyntax.add_parsers -- this functionality is now included in
  2829 OuterSyntax.command etc.  INCOMPATIBILITY.
  2830 
  2831 * Simplifier: the simpset of a running simplification process now
  2832 contains a proof context (cf. Simplifier.the_context), which is the
  2833 very context that the initial simpset has been retrieved from (by
  2834 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2835 (solver, looper etc.) may depend on arbitrary proof data.
  2836 
  2837 * Simplifier.inherit_context inherits the proof context (plus the
  2838 local bounds) of the current simplification process; any simproc
  2839 etc. that calls the Simplifier recursively should do this!  Removed
  2840 former Simplifier.inherit_bounds, which is already included here --
  2841 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2842 specify an explicit context using Simplifier.context/theory_context.
  2843 
  2844 * Simplifier/Classical Reasoner: more abstract interfaces
  2845 change_simpset/claset for modifying the simpset/claset reference of a
  2846 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2847 INCOMPATIBILITY.
  2848 
  2849 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2850 "Trueprop" etc.
  2851 
  2852 
  2853 *** System ***
  2854 
  2855 * settings: the default heap location within ISABELLE_HOME_USER now
  2856 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2857 Isabelle installations.
  2858 
  2859 * isabelle-process: option -S (secure mode) disables some critical
  2860 operations, notably runtime compilation and evaluation of ML source
  2861 code.
  2862 
  2863 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2864 
  2865 * Support for parallel execution, using native multicore support of
  2866 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2867 independent theories, according to the given theory header
  2868 specifications. The maximum number of worker threads is specified via
  2869 usedir option -M or the "max-threads" setting in Proof General. A
  2870 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2871 to 6 on a 8-core machine.  User-code needs to observe certain
  2872 guidelines for thread-safe programming, see appendix A in the Isar
  2873 Implementation manual.
  2874 
  2875 
  2876 
  2877 New in Isabelle2005 (October 2005)
  2878 ----------------------------------
  2879 
  2880 *** General ***
  2881 
  2882 * Theory headers: the new header syntax for Isar theories is
  2883 
  2884   theory <name>
  2885   imports <theory1> ... <theoryN>
  2886   uses <file1> ... <fileM>
  2887   begin
  2888 
  2889 where the 'uses' part is optional.  The previous syntax
  2890 
  2891   theory <name> = <theory1> + ... + <theoryN>:
  2892 
  2893 will disappear in the next release.  Use isatool fixheaders to convert
  2894 existing theory files.  Note that there is no change in ancient
  2895 non-Isar theories now, but these will disappear soon.
  2896 
  2897 * Theory loader: parent theories can now also be referred to via
  2898 relative and absolute paths.
  2899 
  2900 * Command 'find_theorems' searches for a list of criteria instead of a
  2901 list of constants. Known criteria are: intro, elim, dest, name:string,
  2902 simp:term, and any term. Criteria can be preceded by '-' to select
  2903 theorems that do not match. Intro, elim, dest select theorems that
  2904 match the current goal, name:s selects theorems whose fully qualified
  2905 name contain s, and simp:term selects all simplification rules whose
  2906 lhs match term.  Any other term is interpreted as pattern and selects
  2907 all theorems matching the pattern. Available in ProofGeneral under
  2908 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2909 
  2910   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2911 
  2912 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2913 matching the current goal as introduction rule and not having "HOL."
  2914 in their name (i.e. not being defined in theory HOL).
  2915 
  2916 * Command 'thms_containing' has been discontinued in favour of
  2917 'find_theorems'; INCOMPATIBILITY.
  2918 
  2919 * Communication with Proof General is now 8bit clean, which means that
  2920 Unicode text in UTF-8 encoding may be used within theory texts (both
  2921 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2922 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2923 
  2924   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2925   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2926 
  2927 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2928 Classical Reasoner.  Typical big applications run around 2 times
  2929 faster.
  2930 
  2931 
  2932 *** Document preparation ***
  2933 
  2934 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2935 of raw sources.  Only those symbols that do not require additional
  2936 LaTeX packages (depending on comments in isabellesym.sty) are
  2937 displayed properly, everything else is left verbatim.  isatool display
  2938 and isatool print are used as front ends (these are subject to the
  2939 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2940 
  2941 * Command tags control specific markup of certain regions of text,
  2942 notably folding and hiding.  Predefined tags include "theory" (for
  2943 theory begin and end), "proof" for proof commands, and "ML" for
  2944 commands involving ML code; the additional tags "visible" and
  2945 "invisible" are unused by default.  Users may give explicit tag
  2946 specifications in the text, e.g. ''by %invisible (auto)''.  The
  2947 interpretation of tags is determined by the LaTeX job during document
  2948 preparation: see option -V of isatool usedir, or options -n and -t of
  2949 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  2950 \isadroptag.
  2951 
  2952 Several document versions may be produced at the same time via isatool
  2953 usedir (the generated index.html will link all of them).  Typical
  2954 specifications include ''-V document=theory,proof,ML'' to present
  2955 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  2956 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  2957 these parts without any formal replacement text.  The Isabelle site
  2958 default settings produce ''document'' and ''outline'' versions as
  2959 specified above.
  2960 
  2961 * Several new antiquotations:
  2962 
  2963   @{term_type term} prints a term with its type annotated;
  2964 
  2965   @{typeof term} prints the type of a term;
  2966 
  2967   @{const const} is the same as @{term const}, but checks that the
  2968   argument is a known logical constant;
  2969 
  2970   @{term_style style term} and @{thm_style style thm} print a term or
  2971   theorem applying a "style" to it
  2972 
  2973   @{ML text}
  2974 
  2975 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  2976 definitions, equations, inequations etc., 'concl' printing only the
  2977 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  2978 to print the specified premise.  TermStyle.add_style provides an ML
  2979 interface for introducing further styles.  See also the "LaTeX Sugar"
  2980 document practical applications.  The ML antiquotation prints
  2981 type-checked ML expressions verbatim.
  2982 
  2983 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  2984 and 'text' support optional locale specification '(in loc)', which
  2985 specifies the default context for interpreting antiquotations.  For
  2986 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  2987 
  2988 * Option 'locale=NAME' of antiquotations specifies an alternative
  2989 context interpreting the subsequent argument.  For example: @{thm
  2990 [locale=lattice] inf_assoc}.
  2991 
  2992 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  2993 a proof context.
  2994 
  2995 * Proper output of antiquotations for theory commands involving a
  2996 proof context (such as 'locale' or 'theorem (in loc) ...').
  2997 
  2998 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  2999 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3000 
  3001 * isatool usedir: new option -C (default true) controls whether option
  3002 -D should include a copy of the original document directory; -C false
  3003 prevents unwanted effects such as copying of administrative CVS data.
  3004 
  3005 
  3006 *** Pure ***
  3007 
  3008 * Considerably improved version of 'constdefs' command.  Now performs
  3009 automatic type-inference of declared constants; additional support for
  3010 local structure declarations (cf. locales and HOL records), see also
  3011 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3012 sequential dependencies of definitions within a single 'constdefs'
  3013 section; moreover, the declared name needs to be an identifier.  If
  3014 all fails, consider to fall back on 'consts' and 'defs' separately.
  3015 
  3016 * Improved indexed syntax and implicit structures.  First of all,
  3017 indexed syntax provides a notational device for subscripted
  3018 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3019 expressions.  Secondly, in a local context with structure
  3020 declarations, number indexes \<^sub>n or the empty index (default
  3021 number 1) refer to a certain fixed variable implicitly; option
  3022 show_structs controls printing of implicit structures.  Typical
  3023 applications of these concepts involve record types and locales.
  3024 
  3025 * New command 'no_syntax' removes grammar declarations (and
  3026 translations) resulting from the given syntax specification, which is
  3027 interpreted in the same manner as for the 'syntax' command.
  3028 
  3029 * 'Advanced' translation functions (parse_translation etc.) may depend
  3030 on the signature of the theory context being presently used for
  3031 parsing/printing, see also isar-ref manual.
  3032 
  3033 * Improved 'oracle' command provides a type-safe interface to turn an
  3034 ML expression of type theory -> T -> term into a primitive rule of
  3035 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3036 is already included here); see also FOL/ex/IffExample.thy;
  3037 INCOMPATIBILITY.
  3038 
  3039 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3040 before); "cI" is no longer bound, use "c.intro" instead.
  3041 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3042 axclasses vs. locales.
  3043 
  3044 * Improved internal renaming of symbolic identifiers -- attach primes
  3045 instead of base 26 numbers.
  3046 
  3047 * New flag show_question_marks controls printing of leading question
  3048 marks in schematic variable names.
  3049 
  3050 * In schematic variable names, *any* symbol following \<^isub> or
  3051 \<^isup> is now treated as part of the base name.  For example, the
  3052 following works without printing of awkward ".0" indexes:
  3053 
  3054   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3055     by simp
  3056 
  3057 * Inner syntax includes (*(*nested*) comments*).
  3058 
  3059 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3060 annotations as "(00...)".
  3061 
  3062 * Clear separation of logical types and nonterminals, where the latter
  3063 may only occur in 'syntax' specifications or type abbreviations.
  3064 Before that distinction was only partially implemented via type class
  3065 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3066 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3067 exotic syntax specifications may require further adaption
  3068 (e.g. Cube/Cube.thy).
  3069 
  3070 * Removed obsolete type class "logic", use the top sort {} instead.
  3071 Note that non-logical types should be declared as 'nonterminals'
  3072 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3073 specifications.
  3074 
  3075 * Attributes 'induct' and 'cases': type or set names may now be
  3076 locally fixed variables as well.
  3077 
  3078 * Simplifier: can now control the depth to which conditional rewriting
  3079 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3080 Limit.
  3081 
  3082 * Simplifier: simplification procedures may now take the current
  3083 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3084 interface), which is very useful for calling the Simplifier
  3085 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3086 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3087 low-level mk_simproc no longer applies Logic.varify internally, to
  3088 allow for use in a context of fixed variables.
  3089 
  3090 * thin_tac now works even if the assumption being deleted contains !!
  3091 or ==>.  More generally, erule now works even if the major premise of
  3092 the elimination rule contains !! or ==>.
  3093 
  3094 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3095 
  3096 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3097 from Pure, which contains all common declarations already.  Both
  3098 theories are defined via plain Isabelle/Isar .thy files.
  3099 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3100 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3101 use isatool fixcpure to adapt your theory and ML sources.
  3102 
  3103 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3104 selections of theorems in named facts via index ranges.
  3105 
  3106 * 'print_theorems': in theory mode, really print the difference
  3107 wrt. the last state (works for interactive theory development only),
  3108 in proof mode print all local facts (cf. 'print_facts');
  3109 
  3110 * 'hide': option '(open)' hides only base names.
  3111 
  3112 * More efficient treatment of intermediate checkpoints in interactive
  3113 theory development.
  3114 
  3115 * Code generator is now invoked via code_module (incremental code
  3116 generation) and code_library (modular code generation, ML structures
  3117 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3118 must be quoted when used as identifiers.
  3119 
  3120 * New 'value' command for reading, evaluating and printing terms using
  3121 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3122 quoted when used as identifier.
  3123 
  3124 
  3125 *** Locales ***
  3126 
  3127 * New commands for the interpretation of locale expressions in
  3128 theories (1), locales (2) and proof contexts (3).  These generate
  3129 proof obligations from the expression specification.  After the
  3130 obligations have been discharged, theorems of the expression are added
  3131 to the theory, target locale or proof context.  The synopsis of the
  3132 commands is a follows:
  3133 
  3134   (1) interpretation expr inst
  3135   (2) interpretation target < expr
  3136   (3) interpret expr inst
  3137 
  3138 Interpretation in theories and proof contexts require a parameter
  3139 instantiation of terms from the current context.  This is applied to
  3140 specifications and theorems of the interpreted expression.
  3141 Interpretation in locales only permits parameter renaming through the
  3142 locale expression.  Interpretation is smart in that interpretations
  3143 that are active already do not occur in proof obligations, neither are
  3144 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3145 inspect active interpretations of a particular locale.  For details,
  3146 see the Isar Reference manual.  Examples can be found in
  3147 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3148 
  3149 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3150 'interpret' instead.
  3151 
  3152 * New context element 'constrains' for adding type constraints to
  3153 parameters.
  3154 
  3155 * Context expressions: renaming of parameters with syntax
  3156 redeclaration.
  3157 
  3158 * Locale declaration: 'includes' disallowed.
  3159 
  3160 * Proper static binding of attribute syntax -- i.e. types / terms /
  3161 facts mentioned as arguments are always those of the locale definition
  3162 context, independently of the context of later invocations.  Moreover,
  3163 locale operations (renaming and type / term instantiation) are applied
  3164 to attribute arguments as expected.
  3165 
  3166 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3167 actual attributes; rare situations may require Attrib.attribute to
  3168 embed those attributes into Attrib.src that lack concrete syntax.
  3169 Attribute implementations need to cooperate properly with the static
  3170 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3171 Attrib.XXX_thm etc. already do the right thing without further
  3172 intervention.  Only unusual applications -- such as "where" or "of"
  3173 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3174 on the context and the facts involved -- may have to assign parsed
  3175 values to argument tokens explicitly.
  3176 
  3177 * Changed parameter management in theorem generation for long goal
  3178 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3179 theorem statement in rare situations.
  3180 
  3181 * Locale inspection command 'print_locale' omits notes elements.  Use
  3182 'print_locale!' to have them included in the output.
  3183 
  3184 
  3185 *** Provers ***
  3186 
  3187 * Provers/hypsubst.ML: improved version of the subst method, for
  3188 single-step rewriting: it now works in bound variable contexts. New is
  3189 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3190 rewrite a different subterm than the original subst method, which is
  3191 still available as 'simplesubst'.
  3192 
  3193 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3194 and quasi orders.
  3195 
  3196 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3197 reflexive-transitive closure of relations.
  3198 
  3199 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3200 limit (previously hard-coded with a value of 20) user-definable.
  3201 
  3202 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3203 is peformed already.  Object-logics merely need to finish their
  3204 initial simpset configuration as before.  INCOMPATIBILITY.
  3205 
  3206 
  3207 *** HOL ***
  3208 
  3209 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3210 
  3211   syntax (epsilon)
  3212     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3213 
  3214 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3215 and x-symbol; use option '-m epsilon' to get it actually printed.
  3216 Moreover, the mathematically important symbolic identifier \<epsilon>
  3217 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3218 
  3219 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3220 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3221 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3222 support corresponding Isar calculations.
  3223 
  3224 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3225 instead of ":".
  3226 
  3227 * theory SetInterval: changed the syntax for open intervals:
  3228 
  3229   Old       New
  3230   {..n(}    {..<n}
  3231   {)n..}    {n<..}
  3232   {m..n(}   {m..<n}
  3233   {)m..n}   {m<..n}
  3234   {)m..n(}  {m<..<n}
  3235 
  3236 The old syntax is still supported but will disappear in the next
  3237 release.  For conversion use the following Emacs search and replace
  3238 patterns (these are not perfect but work quite well):
  3239 
  3240   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3241   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3242 
  3243 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3244 equalities in commutative rings; method 'algebra' provides a generic
  3245 interface.
  3246 
  3247 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3248 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3249 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3250 be a tuple pattern.
  3251 
  3252 Some new syntax forms are available:
  3253 
  3254   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3255   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3256   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3257   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3258 
  3259 The latter form "\<Sum>x < k. e" used to be based on a separate
  3260 function "Summation", which has been discontinued.
  3261 
  3262 * theory Finite_Set: in structured induction proofs, the insert case
  3263 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3264 (insert F x)'.
  3265 
  3266 * The 'refute' command has been extended to support a much larger
  3267 fragment of HOL, including axiomatic type classes, constdefs and
  3268 typedefs, inductive datatypes and recursion.
  3269 
  3270 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3271 Requires zChaff with proof generation to be installed.  See
  3272 HOL/ex/SAT_Examples.thy for examples.
  3273 
  3274 * Datatype induction via method 'induct' now preserves the name of the
  3275 induction variable. For example, when proving P(xs::'a list) by
  3276 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3277 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3278 in unstructured proof scripts.
  3279 
  3280 * Reworked implementation of records.  Improved scalability for
  3281 records with many fields, avoiding performance problems for type
  3282 inference. Records are no longer composed of nested field types, but
  3283 of nested extension types. Therefore the record type only grows linear
  3284 in the number of extensions and not in the number of fields.  The
  3285 top-level (users) view on records is preserved.  Potential
  3286 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3287 old record representation. The type generated for a record is called
  3288 <record_name>_ext_type.
  3289 
  3290 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3291 proofs triggered by a record definition or a simproc (if
  3292 quick_and_dirty is enabled).  Definitions of large records can take
  3293 quite long.
  3294 
  3295 New simproc record_upd_simproc for simplification of multiple record
  3296 updates enabled by default.  Moreover, trivial updates are also
  3297 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3298 occasionally, since simplification is more powerful by default.
  3299 
  3300 * typedef: proper support for polymorphic sets, which contain extra
  3301 type-variables in the term.
  3302 
  3303 * Simplifier: automatically reasons about transitivity chains
  3304 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3305 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3306 old proofs break occasionally as simplification may now solve more
  3307 goals than previously.
  3308 
  3309 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3310 present.  Works for all partial orders (class "order"), in particular
  3311 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3312 just like y <= x.
  3313 
  3314 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3315 bound variable or a constant then the let is unfolded.  Otherwise
  3316 first a is simplified to b, and then f b is simplified to g. If
  3317 possible we abstract b from g arriving at "let x = b in h x",
  3318 otherwise we unfold the let and arrive at g.  The simproc can be
  3319 enabled/disabled by the reference use_let_simproc.  Potential
  3320 INCOMPATIBILITY since simplification is more powerful by default.
  3321 
  3322 * Classical reasoning: the meson method now accepts theorems as arguments.
  3323 
  3324 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3325 jobs to provide advice on the provability of subgoals.
  3326 
  3327 * Theory OrderedGroup and Ring_and_Field: various additions and
  3328 improvements to faciliate calculations involving equalities and
  3329 inequalities.
  3330 
  3331 The following theorems have been eliminated or modified
  3332 (INCOMPATIBILITY):
  3333 
  3334   abs_eq             now named abs_of_nonneg
  3335   abs_of_ge_0        now named abs_of_nonneg
  3336   abs_minus_eq       now named abs_of_nonpos
  3337   imp_abs_id         now named abs_of_nonneg
  3338   imp_abs_neg_id     now named abs_of_nonpos
  3339   mult_pos           now named mult_pos_pos
  3340   mult_pos_le        now named mult_nonneg_nonneg
  3341   mult_pos_neg_le    now named mult_nonneg_nonpos
  3342   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3343   mult_neg           now named mult_neg_neg
  3344   mult_neg_le        now named mult_nonpos_nonpos
  3345 
  3346 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3347      
  3348      zero_le_square
  3349      not_square_less_zero 
  3350 
  3351   The following lemmas have been deleted from Real/RealPow:
  3352   
  3353      realpow_zero_zero
  3354      realpow_two
  3355      realpow_less
  3356      zero_le_power
  3357      realpow_two_le
  3358      abs_realpow_two
  3359      realpow_two_abs     
  3360 
  3361 * Theory Parity: added rules for simplifying exponents.
  3362 
  3363 * Theory List:
  3364 
  3365 The following theorems have been eliminated or modified
  3366 (INCOMPATIBILITY):
  3367 
  3368   list_all_Nil       now named list_all.simps(1)
  3369   list_all_Cons      now named list_all.simps(2)
  3370   list_all_conv      now named list_all_iff
  3371   set_mem_eq         now named mem_iff
  3372 
  3373 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3374 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3375 
  3376 
  3377 *** HOL-Complex ***
  3378 
  3379 * Theory RealDef: better support for embedding natural numbers and
  3380 integers in the reals.
  3381 
  3382 The following theorems have been eliminated or modified
  3383 (INCOMPATIBILITY):
  3384 
  3385   exp_ge_add_one_self  now requires no hypotheses
  3386   real_of_int_add      reversed direction of equality (use [symmetric])
  3387   real_of_int_minus    reversed direction of equality (use [symmetric])
  3388   real_of_int_diff     reversed direction of equality (use [symmetric])
  3389   real_of_int_mult     reversed direction of equality (use [symmetric])
  3390 
  3391 * Theory RComplete: expanded support for floor and ceiling functions.
  3392 
  3393 * Theory Ln is new, with properties of the natural logarithm
  3394 
  3395 * Hyperreal: There is a new type constructor "star" for making
  3396 nonstandard types.  The old type names are now type synonyms:
  3397 
  3398   hypreal = real star
  3399   hypnat = nat star
  3400   hcomplex = complex star
  3401 
  3402 * Hyperreal: Many groups of similarly-defined constants have been
  3403 replaced by polymorphic versions (INCOMPATIBILITY):
  3404 
  3405   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3406 
  3407   starset      <-- starsetNat, starsetC
  3408   *s*          <-- *sNat*, *sc*
  3409   starset_n    <-- starsetNat_n, starsetC_n
  3410   *sn*         <-- *sNatn*, *scn*
  3411   InternalSets <-- InternalNatSets, InternalCSets
  3412 
  3413   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3414   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3415   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3416   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3417   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3418 
  3419 * Hyperreal: Many type-specific theorems have been removed in favor of
  3420 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3421 
  3422   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3423   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3424   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3425   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3426   right_minus <-- hypreal_add_minus
  3427   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3428   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3429   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3430   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3431   mult_1_right <-- hcomplex_mult_one_right
  3432   mult_zero_left <-- hcomplex_mult_zero_left
  3433   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3434   right_distrib <-- hypnat_add_mult_distrib2
  3435   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3436   right_inverse <-- hypreal_mult_inverse
  3437   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3438   order_refl <-- {hypreal,hypnat}_le_refl
  3439   order_trans <-- {hypreal,hypnat}_le_trans
  3440   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3441   order_less_le <-- {hypreal,hypnat}_less_le
  3442   linorder_linear <-- {hypreal,hypnat}_le_linear
  3443   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3444   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3445   add_nonneg_nonneg <-- hypreal_le_add_order
  3446 
  3447 * Hyperreal: Separate theorems having to do with type-specific
  3448 versions of constants have been merged into theorems that apply to the
  3449 new polymorphic constants (INCOMPATIBILITY):
  3450 
  3451   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3452   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3453   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3454   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3455   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3456   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3457   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3458   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3459   STAR_diff <-- {STAR,STARC}_diff
  3460   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3461     STARC_hcomplex_of_complex}_image_subset
  3462   starset_n_Un <-- starset{Nat,C}_n_Un
  3463   starset_n_Int <-- starset{Nat,C}_n_Int
  3464   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3465   starset_n_diff <-- starset{Nat,C}_n_diff
  3466   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3467   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3468   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3469   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3470   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3471   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3472   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3473   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3474   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3475   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3476   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3477   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3478   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3479   starfun_diff <-- starfun{C,RC,CR}_diff
  3480   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3481   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3482   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3483   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3484   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3485   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3486   starfun_Id <-- starfunC_Id
  3487   starfun_approx <-- starfun{Nat,CR}_approx
  3488   starfun_capprox <-- starfun{C,RC}_capprox
  3489   starfun_abs <-- starfunNat_rabs
  3490   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3491   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3492   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3493   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3494   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3495   starfun_add_approx <-- starfunCR_add_approx
  3496   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3497   starfun_divide <-- starfun{C,CR,RC}_divide
  3498   starfun_n <-- starfun{Nat,C}_n
  3499   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3500   starfun_n_add <-- starfun{Nat,C}_n_add
  3501   starfun_n_add_minus <-- starfunNat_n_add_minus
  3502   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3503   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3504   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3505 
  3506   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3507   star_n_minus <-- {hypreal,hcomplex}_minus
  3508   star_n_diff <-- {hypreal,hcomplex}_diff
  3509   star_n_mult <-- {hypreal,hcomplex}_mult
  3510   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3511   star_n_le <-- {hypreal,hypnat}_le
  3512   star_n_less <-- {hypreal,hypnat}_less
  3513   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3514   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3515   star_n_abs <-- hypreal_hrabs
  3516   star_n_divide <-- hcomplex_divide
  3517 
  3518   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3519   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3520   star_of_diff <-- hypreal_of_real_diff
  3521   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3522   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3523   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3524   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3525   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3526   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3527   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3528   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3529   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3530   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3531   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3532   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3533   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3534   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3535   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3536   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3537   star_of_power <-- hypreal_of_real_power
  3538   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3539 
  3540 * Hyperreal: new method "transfer" that implements the transfer
  3541 principle of nonstandard analysis. With a subgoal that mentions
  3542 nonstandard types like "'a star", the command "apply transfer"
  3543 replaces it with an equivalent one that mentions only standard types.
  3544 To be successful, all free variables must have standard types; non-
  3545 standard variables must have explicit universal quantifiers.
  3546 
  3547 * Hyperreal: A theory of Taylor series.
  3548 
  3549 
  3550 *** HOLCF ***
  3551 
  3552 * Discontinued special version of 'constdefs' (which used to support
  3553 continuous functions) in favor of the general Pure one with full
  3554 type-inference.
  3555 
  3556 * New simplification procedure for solving continuity conditions; it
  3557 is much faster on terms with many nested lambda abstractions (cubic
  3558 instead of exponential time).
  3559 
  3560 * New syntax for domain package: selector names are now optional.
  3561 Parentheses should be omitted unless argument is lazy, for example:
  3562 
  3563   domain 'a stream = cons "'a" (lazy "'a stream")
  3564 
  3565 * New command 'fixrec' for defining recursive functions with pattern
  3566 matching; defining multiple functions with mutual recursion is also
  3567 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3568 sinr, or any data constructor defined by the domain package. The given
  3569 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3570 syntax and examples.
  3571 
  3572 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3573 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3574 but the proof obligation additionally includes an admissibility
  3575 requirement. The packages generate instances of class cpo or pcpo,
  3576 with continuity and strictness theorems for Rep and Abs.
  3577 
  3578 * HOLCF: Many theorems have been renamed according to a more standard naming
  3579 scheme (INCOMPATIBILITY):
  3580 
  3581   foo_inject:  "foo$x = foo$y ==> x = y"
  3582   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3583   foo_less:    "(foo$x << foo$y) = (x << y)"
  3584   foo_strict:  "foo$UU = UU"
  3585   foo_defined: "... ==> foo$x ~= UU"
  3586   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3587 
  3588 
  3589 *** ZF ***
  3590 
  3591 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3592 including the First Isomorphism Theorem (on quotienting by the kernel
  3593 of a homomorphism).
  3594 
  3595 * ZF/Simplifier: install second copy of type solver that actually
  3596 makes use of TC rules declared to Isar proof contexts (or locales);
  3597 the old version is still required for ML proof scripts.
  3598 
  3599 
  3600 *** Cube ***
  3601 
  3602 * Converted to Isar theory format; use locales instead of axiomatic
  3603 theories.
  3604 
  3605 
  3606 *** ML ***
  3607 
  3608 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3609 for ||>, ||>>, |>>,
  3610 
  3611 * Pure/library.ML no longer defines its own option datatype, but uses
  3612 that of the SML basis, which has constructors NONE and SOME instead of
  3613 None and Some, as well as exception Option.Option instead of OPTION.
  3614 The functions the, if_none, is_some, is_none have been adapted
  3615 accordingly, while Option.map replaces apsome.
  3616 
  3617 * Pure/library.ML: the exception LIST has been given up in favour of
  3618 the standard exceptions Empty and Subscript, as well as
  3619 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3620 superceded by the standard hd and tl functions etc.
  3621 
  3622 A number of basic list functions are no longer exported to the ML
  3623 toplevel, as they are variants of predefined functions.  The following
  3624 suggests how one can translate existing code:
  3625 
  3626     rev_append xs ys = List.revAppend (xs, ys)
  3627     nth_elem (i, xs) = List.nth (xs, i)
  3628     last_elem xs = List.last xs
  3629     flat xss = List.concat xss
  3630     seq fs = List.app fs
  3631     partition P xs = List.partition P xs
  3632     mapfilter f xs = List.mapPartial f xs
  3633 
  3634 * Pure/library.ML: several combinators for linear functional
  3635 transformations, notably reverse application and composition:
  3636 
  3637   x |> f                f #> g
  3638   (x, y) |-> f          f #-> g
  3639 
  3640 * Pure/library.ML: introduced/changed precedence of infix operators:
  3641 
  3642   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3643   infix 2 ?;
  3644   infix 3 o oo ooo oooo;
  3645   infix 4 ~~ upto downto;
  3646 
  3647 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3648 infix operators.
  3649 
  3650 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3651 fold_map support linear functional transformations and nesting.  For
  3652 example:
  3653 
  3654   fold f [x1, ..., xN] y =
  3655     y |> f x1 |> ... |> f xN
  3656 
  3657   (fold o fold) f [xs1, ..., xsN] y =
  3658     y |> fold f xs1 |> ... |> fold f xsN
  3659 
  3660   fold f [x1, ..., xN] =
  3661     f x1 #> ... #> f xN
  3662 
  3663   (fold o fold) f [xs1, ..., xsN] =
  3664     fold f xs1 #> ... #> fold f xsN
  3665 
  3666 * Pure/library.ML: the following selectors on type 'a option are
  3667 available:
  3668 
  3669   the:               'a option -> 'a  (*partial*)
  3670   these:             'a option -> 'a  where 'a = 'b list
  3671   the_default: 'a -> 'a option -> 'a
  3672   the_list:          'a option -> 'a list
  3673 
  3674 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3675 basic operations for association lists, following natural argument
  3676 order; moreover the explicit equality predicate passed here avoids
  3677 potentially expensive polymorphic runtime equality checks.
  3678 The old functions may be expressed as follows:
  3679 
  3680   assoc = uncurry (AList.lookup (op =))
  3681   assocs = these oo AList.lookup (op =)
  3682   overwrite = uncurry (AList.update (op =)) o swap
  3683 
  3684 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3685 
  3686   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3687   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3688 
  3689 replacing make_keylist and keyfilter (occassionally used)
  3690 Naive rewrites:
  3691 
  3692   make_keylist = AList.make
  3693   keyfilter = AList.find (op =)
  3694 
  3695 * eq_fst and eq_snd now take explicit equality parameter, thus
  3696   avoiding eqtypes. Naive rewrites:
  3697 
  3698     eq_fst = eq_fst (op =)
  3699     eq_snd = eq_snd (op =)
  3700 
  3701 * Removed deprecated apl and apr (rarely used).
  3702   Naive rewrites:
  3703 
  3704     apl (n, op) =>>= curry op n
  3705     apr (op, m) =>>= fn n => op (n, m)
  3706 
  3707 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3708 provides a reasonably efficient light-weight implementation of sets as
  3709 lists.
  3710 
  3711 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3712 few new operations; existing lookup and update are now curried to
  3713 follow natural argument order (for use with fold etc.);
  3714 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3715 
  3716 * Pure/General: output via the Isabelle channels of
  3717 writeln/warning/error etc. is now passed through Output.output, with a
  3718 hook for arbitrary transformations depending on the print_mode
  3719 (cf. Output.add_mode -- the first active mode that provides a output
  3720 function wins).  Already formatted output may be embedded into further
  3721 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3722 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3723 accommodate easy composition of diagnostic messages etc.  Programmers
  3724 rarely need to care about Output.output or Output.raw at all, with
  3725 some notable exceptions: Output.output is required when bypassing the
  3726 standard channels (writeln etc.), or in token translations to produce
  3727 properly formatted results; Output.raw is required when capturing
  3728 already output material that will eventually be presented to the user
  3729 a second time.  For the default print mode, both Output.output and
  3730 Output.raw have no effect.
  3731 
  3732 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3733 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3734 cumulative results are displayed at the end of a batch session.
  3735 
  3736 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3737 replaced by File.platform_path and File.shell_path (with appropriate
  3738 hooks).  This provides a clean interface for unusual systems where the
  3739 internal and external process view of file names are different.
  3740 
  3741 * Pure: more efficient orders for basic syntactic entities: added
  3742 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3743 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3744 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3745 orders now -- potential INCOMPATIBILITY for code that depends on a
  3746 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3747 Library.sort_strings on result).
  3748 
  3749 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3750 fold_types traverse types/terms from left to right, observing natural
  3751 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3752 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3753 
  3754 * Pure: name spaces have been refined, with significant changes of the
  3755 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3756 to extern(_table).  The plain name entry path is superceded by a
  3757 general 'naming' context, which also includes the 'policy' to produce
  3758 a fully qualified name and external accesses of a fully qualified
  3759 name; NameSpace.extend is superceded by context dependent
  3760 Sign.declare_name.  Several theory and proof context operations modify
  3761 the naming context.  Especially note Theory.restore_naming and
  3762 ProofContext.restore_naming to get back to a sane state; note that
  3763 Theory.add_path is no longer sufficient to recover from
  3764 Theory.absolute_path in particular.
  3765 
  3766 * Pure: new flags short_names (default false) and unique_names
  3767 (default true) for controlling output of qualified names.  If
  3768 short_names is set, names are printed unqualified.  If unique_names is
  3769 reset, the name prefix is reduced to the minimum required to achieve
  3770 the original result when interning again, even if there is an overlap
  3771 with earlier declarations.
  3772 
  3773 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3774 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3775 (useful for printing error messages).  INCOMPATIBILITY.
  3776 
  3777 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3778 Theory.theory are now identified, referring to the universal
  3779 Context.theory (see Pure/context.ML).  Actual signature and theory
  3780 content is managed as theory data.  The old code and interfaces were
  3781 spread over many files and structures; the new arrangement introduces
  3782 considerable INCOMPATIBILITY to gain more clarity:
  3783 
  3784   Context -- theory management operations (name, identity, inclusion,
  3785     parents, ancestors, merge, etc.), plus generic theory data;
  3786 
  3787   Sign -- logical signature and syntax operations (declaring consts,
  3788     types, etc.), plus certify/read for common entities;
  3789 
  3790   Theory -- logical theory operations (stating axioms, definitions,
  3791     oracles), plus a copy of logical signature operations (consts,
  3792     types, etc.); also a few basic management operations (Theory.copy,
  3793     Theory.merge, etc.)
  3794 
  3795 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3796 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3797 for convenience -- they merely return the theory.
  3798 
  3799 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3800 
  3801 * Pure: the Isar proof context type is already defined early in Pure
  3802 as Context.proof (note that ProofContext.context and Proof.context are
  3803 aliases, where the latter is the preferred name).  This enables other
  3804 Isabelle components to refer to that type even before Isar is present.
  3805 
  3806 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3807 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3808 any of these kinds.  For example, Sign.intern typeK is now
  3809 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3810 Theory.hide_types.  Also note that former
  3811 Theory.hide_classes/types/consts are now
  3812 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3813 internalize their arguments!  INCOMPATIBILITY.
  3814 
  3815 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3816 datatype thmref (with constructors Name and NameSelection) instead of
  3817 plain string -- INCOMPATIBILITY;
  3818 
  3819 * Pure: cases produced by proof methods specify options, where NONE
  3820 means to remove case bindings -- INCOMPATIBILITY in
  3821 (RAW_)METHOD_CASES.
  3822 
  3823 * Pure: the following operations retrieve axioms or theorems from a
  3824 theory node or theory hierarchy, respectively:
  3825 
  3826   Theory.axioms_of: theory -> (string * term) list
  3827   Theory.all_axioms_of: theory -> (string * term) list
  3828   PureThy.thms_of: theory -> (string * thm) list
  3829   PureThy.all_thms_of: theory -> (string * thm) list
  3830 
  3831 * Pure: print_tac now outputs the goal through the trace channel.
  3832 
  3833 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3834 Reference Toplevel.debug (default false) controls detailed printing
  3835 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3836 controls execution profiling -- set to 1 for time and 2 for space
  3837 (both increase the runtime).
  3838 
  3839 * Isar session: The initial use of ROOT.ML is now always timed,
  3840 i.e. the log will show the actual process times, in contrast to the
  3841 elapsed wall-clock time that the outer shell wrapper produces.
  3842 
  3843 * Simplifier: improved handling of bound variables (nameless
  3844 representation, avoid allocating new strings).  Simprocs that invoke
  3845 the Simplifier recursively should use Simplifier.inherit_bounds to
  3846 avoid local name clashes.  Failure to do so produces warnings
  3847 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3848 for further details.
  3849 
  3850 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3851 bindings for all theorems stored within a given theory; this may help
  3852 in porting non-Isar theories to Isar ones, while keeping ML proof
  3853 scripts for the time being.
  3854 
  3855 * ML operator HTML.with_charset specifies the charset begin used for
  3856 generated HTML files.  For example:
  3857 
  3858   HTML.with_charset "utf-8" use_thy "Hebrew";
  3859   HTML.with_charset "utf-8" use_thy "Chinese";
  3860 
  3861 
  3862 *** System ***
  3863 
  3864 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3865 isabelle, isatool etc.).
  3866 
  3867 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3868 isatool doc, isatool mkdir, display_drafts etc.).
  3869 
  3870 * isatool usedir: option -f allows specification of the ML file to be
  3871 used by Isabelle; default is ROOT.ML.
  3872 
  3873 * New isatool version outputs the version identifier of the Isabelle
  3874 distribution being used.
  3875 
  3876 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3877 (containing Boolean satisfiability problems) into Isabelle/HOL
  3878 theories.
  3879 
  3880 
  3881 
  3882 New in Isabelle2004 (April 2004)
  3883 --------------------------------
  3884 
  3885 *** General ***
  3886 
  3887 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3888   Replaces linorder.ML.
  3889 
  3890 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3891   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3892   (\<a>...\<z>), are now considered normal letters, and can therefore
  3893   be used anywhere where an ASCII letter (a...zA...Z) has until
  3894   now. COMPATIBILITY: This obviously changes the parsing of some
  3895   terms, especially where a symbol has been used as a binder, say
  3896   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3897   as an identifier.  Fix it by inserting a space around former
  3898   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3899   existing theory and ML files.
  3900 
  3901 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3902 
  3903 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3904   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3905   a normal (but invisible) letter. For multiple letter subscripts repeat
  3906   \<^isub> like this: x\<^isub>1\<^isub>2.
  3907 
  3908 * Pure: There are now sub-/superscripts that can span more than one
  3909   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3910   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3911   superscript. The new control characters are not identifier parts.
  3912 
  3913 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3914   content of "..." to the latex file instead of \isacntrl... . The "..."
  3915   may consist of any printable characters excluding the end bracket >.
  3916 
  3917 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3918   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3919   declare constants "final", which prevents their being given a definition
  3920   later.  It is useful for constants whose behaviour is fixed axiomatically
  3921   rather than definitionally, such as the meta-logic connectives.
  3922 
  3923 * Pure: 'instance' now handles general arities with general sorts
  3924   (i.e. intersections of classes),
  3925 
  3926 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3927   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3928   It can be changed to alter the colors/layout of generated pages.
  3929 
  3930 
  3931 *** Isar ***
  3932 
  3933 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3934   cut_tac, subgoal_tac and thin_tac:
  3935   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3936     locales are no longer forced to write Isar proof scripts.
  3937     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3938     emulations.
  3939   - INCOMPATIBILITY: names of variables to be instantiated may no
  3940     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3941     This is consistent with the instantiation attribute "where".
  3942 
  3943 * Attributes "where" and "of":
  3944   - Now take type variables of instantiated theorem into account when reading
  3945     the instantiation string.  This fixes a bug that caused instantiated
  3946     theorems to have too special types in some circumstances.
  3947   - "where" permits explicit instantiations of type variables.
  3948 
  3949 * Calculation commands "moreover" and "also" no longer interfere with
  3950   current facts ("this"), admitting arbitrary combinations with "then"
  3951   and derived forms.
  3952 
  3953 * Locales:
  3954   - Goal statements involving the context element "includes" no longer
  3955     generate theorems with internal delta predicates (those ending on
  3956     "_axioms") in the premise.
  3957     Resolve particular premise with <locale>.intro to obtain old form.
  3958   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  3959     specification and "includes" elements in goal statement.
  3960   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  3961     [intro?] and [elim?] (respectively) by default.
  3962   - Experimental command for instantiation of locales in proof contexts:
  3963         instantiate <label>[<attrs>]: <loc>
  3964     Instantiates locale <loc> and adds all its theorems to the current context
  3965     taking into account their attributes.  Label and attrs are optional
  3966     modifiers, like in theorem declarations.  If present, names of
  3967     instantiated theorems are qualified with <label>, and the attributes
  3968     <attrs> are applied after any attributes these theorems might have already.
  3969       If the locale has assumptions, a chained fact of the form
  3970     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  3971     are derived.  The command does not support old-style locales declared
  3972     with "locale (open)".
  3973       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  3974 
  3975 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  3976   (Isar) contexts.
  3977 
  3978 
  3979 *** HOL ***
  3980 
  3981 * Proof import: new image HOL4 contains the imported library from
  3982   the HOL4 system with about 2500 theorems. It is imported by
  3983   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  3984   can be used like any other Isabelle image.  See
  3985   HOL/Import/HOL/README for more information.
  3986 
  3987 * Simplifier:
  3988   - Much improved handling of linear and partial orders.
  3989     Reasoners for linear and partial orders are set up for type classes
  3990     "linorder" and "order" respectively, and are added to the default simpset
  3991     as solvers.  This means that the simplifier can build transitivity chains
  3992     to solve goals from the assumptions.
  3993   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  3994     of blast or auto after simplification become unnecessary because the goal
  3995     is solved by simplification already.
  3996 
  3997 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  3998     all proved in axiomatic type classes for semirings, rings and fields.
  3999 
  4000 * Numerics:
  4001   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4002     now formalized using the Ring_and_Field theory mentioned above.
  4003   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4004     than before, because now they are set up once in a generic manner.
  4005   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4006     Look for the general versions in Ring_and_Field (and Power if they concern
  4007     exponentiation).
  4008 
  4009 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4010 
  4011 * Records:
  4012   - Record types are now by default printed with their type abbreviation
  4013     instead of the list of all field types. This can be configured via
  4014     the reference "print_record_type_abbr".
  4015   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4016     (not enabled by default).
  4017   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4018     EX x. x = sel r to True (not enabled by default).
  4019   - Tactic "record_split_simp_tac" to split and simplify records added.
  4020 
  4021 * 'specification' command added, allowing for definition by
  4022   specification.  There is also an 'ax_specification' command that
  4023   introduces the new constants axiomatically.
  4024 
  4025 * arith(_tac) is now able to generate counterexamples for reals as well.
  4026 
  4027 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4028 
  4029 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4030   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4031 
  4032 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4033   matrix theory to linear programming.
  4034 
  4035 * Unions and Intersections:
  4036   The latex output syntax of UN and INT has been changed
  4037   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4038   i.e. the index formulae has become a subscript.
  4039   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4040 
  4041 * Unions and Intersections over Intervals:
  4042   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4043   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4044   like in normal math, and corresponding versions for < and for intersection.
  4045 
  4046 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4047   lexicographic dictonary ordering has been added as "lexord".
  4048 
  4049 * ML: the legacy theory structures Int and List have been removed. They had
  4050   conflicted with ML Basis Library structures having the same names.
  4051 
  4052 * 'refute' command added to search for (finite) countermodels.  Only works
  4053   for a fragment of HOL.  The installation of an external SAT solver is
  4054   highly recommended.  See "HOL/Refute.thy" for details.
  4055 
  4056 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4057   formulae under an assignment of free variables to random values.
  4058   In contrast to 'refute', it can deal with inductive datatypes,
  4059   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4060   for examples.
  4061 
  4062 
  4063 *** HOLCF ***
  4064 
  4065 * Streams now come with concatenation and are part of the HOLCF image
  4066 
  4067 
  4068 
  4069 New in Isabelle2003 (May 2003)
  4070 ------------------------------
  4071 
  4072 *** General ***
  4073 
  4074 * Provers/simplifier:
  4075 
  4076   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4077     Assumptions are now subject to complete mutual simplification,
  4078     not just from left to right. The simplifier now preserves
  4079     the order of assumptions.
  4080 
  4081     Potential INCOMPATIBILITY:
  4082 
  4083     -- simp sometimes diverges where the old version did
  4084        not, e.g. invoking simp on the goal
  4085 
  4086         [| P (f x); y = x; f x = f y |] ==> Q
  4087 
  4088        now gives rise to the infinite reduction sequence
  4089 
  4090         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4091 
  4092        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4093        kind of problem.
  4094 
  4095     -- Tactics combining classical reasoner and simplification (such as auto)
  4096        are also affected by this change, because many of them rely on
  4097        simp. They may sometimes diverge as well or yield a different numbers
  4098        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4099        in case of problems. Sometimes subsequent calls to the classical
  4100        reasoner will fail because a preceeding call to the simplifier too
  4101        eagerly simplified the goal, e.g. deleted redundant premises.
  4102 
  4103   - The simplifier trace now shows the names of the applied rewrite rules
  4104 
  4105   - You can limit the number of recursive invocations of the simplifier
  4106     during conditional rewriting (where the simplifie tries to solve the
  4107     conditions before applying the rewrite rule):
  4108     ML "simp_depth_limit := n"
  4109     where n is an integer. Thus you can force termination where previously
  4110     the simplifier would diverge.
  4111 
  4112   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4113 
  4114   - No longer aborts on failed congruence proof.  Instead, the
  4115     congruence is ignored.
  4116 
  4117 * Pure: New generic framework for extracting programs from constructive
  4118   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4119   as HOL/Extraction for some case studies.
  4120 
  4121 * Pure: The main goal of the proof state is no longer shown by default, only
  4122 the subgoals. This behaviour is controlled by a new flag.
  4123    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4124 (ML: Proof.show_main_goal).
  4125 
  4126 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4127 rules whose conclusion matches subgoal 1:
  4128       PG menu: Isabelle/Isar -> Show me -> matching rules
  4129 The rules are ordered by how closely they match the subgoal.
  4130 In particular, rules that solve a subgoal outright are displayed first
  4131 (or rather last, the way they are printed).
  4132 (ML: ProofGeneral.print_intros())
  4133 
  4134 * Pure: New flag trace_unify_fail causes unification to print
  4135 diagnostic information (PG: in trace buffer) when it fails. This is
  4136 useful for figuring out why single step proofs like rule, erule or
  4137 assumption failed.
  4138 
  4139 * Pure: Locale specifications now produce predicate definitions
  4140 according to the body of text (covering assumptions modulo local
  4141 definitions); predicate "loc_axioms" covers newly introduced text,
  4142 while "loc" is cumulative wrt. all included locale expressions; the
  4143 latter view is presented only on export into the global theory
  4144 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4145 on the old view without predicates;
  4146 
  4147 * Pure: predefined locales "var" and "struct" are useful for sharing
  4148 parameters (as in CASL, for example); just specify something like
  4149 ``var x + var y + struct M'' as import;
  4150 
  4151 * Pure: improved thms_containing: proper indexing of facts instead of
  4152 raw theorems; check validity of results wrt. current name space;
  4153 include local facts of proof configuration (also covers active
  4154 locales), cover fixed variables in index; may use "_" in term
  4155 specification; an optional limit for the number of printed facts may
  4156 be given (the default is 40);
  4157 
  4158 * Pure: disallow duplicate fact bindings within new-style theory files
  4159 (batch-mode only);
  4160 
  4161 * Provers: improved induct method: assumptions introduced by case
  4162 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4163 the goal statement); "foo" still refers to all facts collectively;
  4164 
  4165 * Provers: the function blast.overloaded has been removed: all constants
  4166 are regarded as potentially overloaded, which improves robustness in exchange
  4167 for slight decrease in efficiency;
  4168 
  4169 * Provers/linorder: New generic prover for transitivity reasoning over
  4170 linear orders.  Note: this prover is not efficient!
  4171 
  4172 * Isar: preview of problems to finish 'show' now produce an error
  4173 rather than just a warning (in interactive mode);
  4174 
  4175 
  4176 *** HOL ***
  4177 
  4178 * arith(_tac)
  4179 
  4180  - Produces a counter example if it cannot prove a goal.
  4181    Note that the counter example may be spurious if the goal is not a formula
  4182    of quantifier-free linear arithmetic.
  4183    In ProofGeneral the counter example appears in the trace buffer.
  4184 
  4185  - Knows about div k and mod k where k is a numeral of type nat or int.
  4186 
  4187  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4188    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4189    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4190 
  4191 * simp's arithmetic capabilities have been enhanced a bit: it now
  4192 takes ~= in premises into account (by performing a case split);
  4193 
  4194 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4195 are distributed over a sum of terms;
  4196 
  4197 * New tactic "trans_tac" and method "trans" instantiate
  4198 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4199 "<=", "<" and "=").
  4200 
  4201 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4202 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4203 
  4204 * 'typedef' command has new option "open" to suppress the set
  4205 definition;
  4206 
  4207 * functions Min and Max on finite sets have been introduced (theory
  4208 Finite_Set);
  4209 
  4210 * attribute [symmetric] now works for relations as well; it turns
  4211 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4212 
  4213 * induct over a !!-quantified statement (say !!x1..xn):
  4214   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4215 
  4216 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4217 %x. None. Warning: empty_def now refers to the previously hidden definition
  4218 of the empty set.
  4219 
  4220 * Algebra: formalization of classical algebra.  Intended as base for
  4221 any algebraic development in Isabelle.  Currently covers group theory
  4222 (up to Sylow's theorem) and ring theory (Universal Property of
  4223 Univariate Polynomials).  Contributions welcome;
  4224 
  4225 * GroupTheory: deleted, since its material has been moved to Algebra;
  4226 
  4227 * Complex: new directory of the complex numbers with numeric constants,
  4228 nonstandard complex numbers, and some complex analysis, standard and
  4229 nonstandard (Jacques Fleuriot);
  4230 
  4231 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4232 
  4233 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4234 Fleuriot);
  4235 
  4236 * Real/HahnBanach: updated and adapted to locales;
  4237 
  4238 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4239 Gray and Kramer);
  4240 
  4241 * UNITY: added the Meier-Sanders theory of progress sets;
  4242 
  4243 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4244 as abstract algorithms, instantiated to the JVM;
  4245 
  4246 * Bali: Java source language formalization. Type system, operational
  4247 semantics, axiomatic semantics. Supported language features:
  4248 classes, interfaces, objects,virtual methods, static methods,
  4249 static/instance fields, arrays, access modifiers, definite
  4250 assignment, exceptions.
  4251 
  4252 
  4253 *** ZF ***
  4254 
  4255 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4256 universe, etc.);
  4257 
  4258 * Main ZF: virtually all theories converted to new-style format;
  4259 
  4260 
  4261 *** ML ***
  4262 
  4263 * Pure: Tactic.prove provides sane interface for internal proofs;
  4264 omits the infamous "standard" operation, so this is more appropriate
  4265 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4266 
  4267 * Pure: improved error reporting of simprocs;
  4268 
  4269 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4270 up simprocs;
  4271 
  4272 
  4273 *** Document preparation ***
  4274 
  4275 * uses \par instead of \\ for line breaks in theory text. This may
  4276 shift some page breaks in large documents. To get the old behaviour
  4277 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4278 
  4279 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4280 other packages
  4281 
  4282 * \<euro> now needs package babel/greek instead of marvosym (which
  4283 broke \Rightarrow)
  4284 
  4285 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4286 textcomp package)
  4287 
  4288 
  4289 
  4290 New in Isabelle2002 (March 2002)
  4291 --------------------------------
  4292 
  4293 *** Document preparation ***
  4294 
  4295 * greatly simplified document preparation setup, including more
  4296 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4297 instructive isatool mkdir; users should basically be able to get
  4298 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4299 users may run a separate document processing stage manually like this:
  4300 "isatool usedir -D output HOL Test && isatool document Test/output";
  4301 
  4302 * theory dependency graph may now be incorporated into documents;
  4303 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4304 with \includegraphics of LaTeX;
  4305 
  4306 * proper spacing of consecutive markup elements, especially text
  4307 blocks after section headings;
  4308 
  4309 * support bold style (for single symbols only), input syntax is like
  4310 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4311 
  4312 * \<bullet> is now output as bold \cdot by default, which looks much
  4313 better in printed text;
  4314 
  4315 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4316 note that these symbols are currently unavailable in Proof General /
  4317 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4318 
  4319 * isatool latex no longer depends on changed TEXINPUTS, instead
  4320 isatool document copies the Isabelle style files to the target
  4321 location;
  4322 
  4323 
  4324 *** Isar ***
  4325 
  4326 * Pure/Provers: improved proof by cases and induction;
  4327   - 'case' command admits impromptu naming of parameters (such as
  4328     "case (Suc n)");
  4329   - 'induct' method divinates rule instantiation from the inductive
  4330     claim; no longer requires excessive ?P bindings for proper
  4331     instantiation of cases;
  4332   - 'induct' method properly enumerates all possibilities of set/type
  4333     rules; as a consequence facts may be also passed through *type*
  4334     rules without further ado;
  4335   - 'induct' method now derives symbolic cases from the *rulified*
  4336     rule (before it used to rulify cases stemming from the internal
  4337     atomized version); this means that the context of a non-atomic
  4338     statement becomes is included in the hypothesis, avoiding the
  4339     slightly cumbersome show "PROP ?case" form;
  4340   - 'induct' may now use elim-style induction rules without chaining
  4341     facts, using ``missing'' premises from the goal state; this allows
  4342     rules stemming from inductive sets to be applied in unstructured
  4343     scripts, while still benefitting from proper handling of non-atomic
  4344     statements; NB: major inductive premises need to be put first, all
  4345     the rest of the goal is passed through the induction;
  4346   - 'induct' proper support for mutual induction involving non-atomic
  4347     rule statements (uses the new concept of simultaneous goals, see
  4348     below);
  4349   - append all possible rule selections, but only use the first
  4350     success (no backtracking);
  4351   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4352   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4353   - added 'print_induct_rules' (covered by help item in recent Proof
  4354     General versions);
  4355   - moved induct/cases attributes to Pure, methods to Provers;
  4356   - generic method setup instantiated for FOL and HOL;
  4357 
  4358 * Pure: support multiple simultaneous goal statements, for example
  4359 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4360 meta-level mechanism, this acts as if several individual goals had
  4361 been stated separately; in particular common proof methods need to be
  4362 repeated in order to cover all claims; note that a single elimination
  4363 step is *not* sufficient to establish the two conjunctions, so this
  4364 fails:
  4365 
  4366   assume "A & B" then have A and B ..   (*".." fails*)
  4367 
  4368 better use "obtain" in situations as above; alternative refer to
  4369 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4370 
  4371 * Pure: proper integration with ``locales''; unlike the original
  4372 version by Florian Kammller, Isar locales package high-level proof
  4373 contexts rather than raw logical ones (e.g. we admit to include
  4374 attributes everywhere); operations on locales include merge and
  4375 rename; support for implicit arguments (``structures''); simultaneous
  4376 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4377 some examples;
  4378 
  4379 * Pure: the following commands have been ``localized'', supporting a
  4380 target locale specification "(in name)": 'lemma', 'theorem',
  4381 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4382 stored both within the locale and at the theory level (exported and
  4383 qualified by the locale name);
  4384 
  4385 * Pure: theory goals may now be specified in ``long'' form, with
  4386 ad-hoc contexts consisting of arbitrary locale elements. for example
  4387 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4388 definitions may be given, too); the result is a meta-level rule with
  4389 the context elements being discharged in the obvious way;
  4390 
  4391 * Pure: new proof command 'using' allows to augment currently used
  4392 facts after a goal statement ('using' is syntactically analogous to
  4393 'apply', but acts on the goal's facts only); this allows chained facts
  4394 to be separated into parts given before and after a claim, as in
  4395 ``from a and b have C using d and e <proof>'';
  4396 
  4397 * Pure: renamed "antecedent" case to "rule_context";
  4398 
  4399 * Pure: new 'judgment' command records explicit information about the
  4400 object-logic embedding (used by several tools internally); no longer
  4401 use hard-wired "Trueprop";
  4402 
  4403 * Pure: added 'corollary' command;
  4404 
  4405 * Pure: fixed 'token_translation' command;
  4406 
  4407 * Pure: removed obsolete 'exported' attribute;
  4408 
  4409 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4410 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4411 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4412 
  4413 * Pure: method 'atomize' presents local goal premises as object-level
  4414 statements (atomic meta-level propositions); setup controlled via
  4415 rewrite rules declarations of 'atomize' attribute; example
  4416 application: 'induct' method with proper rule statements in improper
  4417 proof *scripts*;
  4418 
  4419 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4420 now consider the syntactic context of assumptions, giving a better
  4421 chance to get type-inference of the arguments right (this is
  4422 especially important for locales);
  4423 
  4424 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4425 mode;
  4426 
  4427 * Pure/obtain: the formal conclusion "thesis", being marked as
  4428 ``internal'', may no longer be reference directly in the text;
  4429 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4430 situations;
  4431 
  4432 * Pure: generic 'sym' attribute which declares a rule both as pure
  4433 'elim?' and for the 'symmetric' operation;
  4434 
  4435 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4436 text; the fixed correlation with particular command syntax has been
  4437 discontinued;
  4438 
  4439 * Pure: new method 'rules' is particularly well-suited for proof
  4440 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4441 but often produces more compact proof terms with less detours;
  4442 
  4443 * Pure/Provers/classical: simplified integration with pure rule
  4444 attributes and methods; the classical "intro?/elim?/dest?"
  4445 declarations coincide with the pure ones; the "rule" method no longer
  4446 includes classically swapped intros; "intro" and "elim" methods no
  4447 longer pick rules from the context; also got rid of ML declarations
  4448 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4449 INCOMPATIBILITY;
  4450 
  4451 * Provers/classical: attribute 'swapped' produces classical inversions
  4452 of introduction rules;
  4453 
  4454 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4455 rules instead of full simplifier context; 'iff' attribute handles
  4456 conditional rules;
  4457 
  4458 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4459 
  4460 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4461 "(permissive)" option to recover old behavior;
  4462 
  4463 * HOL: 'inductive' no longer features separate (collective) attributes
  4464 for 'intros' (was found too confusing);
  4465 
  4466 * HOL: properly declared induction rules less_induct and
  4467 wf_induct_rule;
  4468 
  4469 
  4470 *** HOL ***
  4471 
  4472 * HOL: moved over to sane numeral syntax; the new policy is as
  4473 follows:
  4474 
  4475   - 0 and 1 are polymorphic constants, which are defined on any
  4476   numeric type (nat, int, real etc.);
  4477 
  4478   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4479   binary representation internally;
  4480 
  4481   - type nat has special constructor Suc, and generally prefers Suc 0
  4482   over 1::nat and Suc (Suc 0) over 2::nat;
  4483 
  4484 This change may cause significant problems of INCOMPATIBILITY; here
  4485 are some hints on converting existing sources:
  4486 
  4487   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4488   entities, so expressions involving "-" (unary or binary minus) need
  4489   to be spaced properly;
  4490 
  4491   - existing occurrences of "1" may need to be constraint "1::nat" or
  4492   even replaced by Suc 0; similar for old "2";
  4493 
  4494   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4495 
  4496   - remove all special provisions on numerals in proofs;
  4497 
  4498 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4499 representation (depends on bin_arith_simps in the default context);
  4500 
  4501 * HOL: symbolic syntax for x^2 (numeral 2);
  4502 
  4503 * HOL: the class of all HOL types is now called "type" rather than
  4504 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4505 in axclass/classes, instance/arities, and (usually rare) occurrences
  4506 in typings (of consts etc.); internally the class is called
  4507 "HOL.type", ML programs should refer to HOLogic.typeS;
  4508 
  4509 * HOL/record package improvements:
  4510   - new derived operations "fields" to build a partial record section,
  4511     "extend" to promote a fixed record to a record scheme, and
  4512     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4513     declared as simp by default;
  4514   - shared operations ("more", "fields", etc.) now need to be always
  4515     qualified) --- potential INCOMPATIBILITY;
  4516   - removed "make_scheme" operations (use "make" with "extend") --
  4517     INCOMPATIBILITY;
  4518   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4519   - provides cases/induct rules for use with corresponding Isar
  4520     methods (for concrete records, record schemes, concrete more
  4521     parts, and schematic more parts -- in that order);
  4522   - internal definitions directly based on a light-weight abstract
  4523     theory of product types over typedef rather than datatype;
  4524 
  4525 * HOL: generic code generator for generating executable ML code from
  4526 specifications; specific support for HOL constructs such as inductive
  4527 datatypes and sets, as well as recursive functions; can be invoked
  4528 via 'generate_code' theory section;
  4529 
  4530 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4531 
  4532 * HOL: consolidated and renamed several theories.  In particular:
  4533         Ord.thy has been absorbed into HOL.thy
  4534         String.thy has been absorbed into List.thy
  4535 
  4536 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4537 (beware of argument permutation!);
  4538 
  4539 * HOL: linorder_less_split superseded by linorder_cases;
  4540 
  4541 * HOL/List: "nodups" renamed to "distinct";
  4542 
  4543 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4544 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4545   - Ex_def has changed, now need to use some_eq_ex
  4546 
  4547 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4548 in this (rare) case use:
  4549 
  4550   delSWrapper "split_all_tac"
  4551   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4552 
  4553 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4554 MAY FAIL;
  4555 
  4556 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4557 Isabelle's type classes, ^ on functions and relations has too general
  4558 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4559 necessary to attach explicit type constraints;
  4560 
  4561 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4562 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4563 renamed accordingly (eg "compI" -> "rel_compI").
  4564 
  4565 * HOL: syntax translations now work properly with numerals and records
  4566 expressions;
  4567 
  4568 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4569 of "lam" -- INCOMPATIBILITY;
  4570 
  4571 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4572 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4573 renamed "Product_Type.unit";
  4574 
  4575 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4576 
  4577 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4578 the "cases" method);
  4579 
  4580 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4581 Florian Kammller);
  4582 
  4583 * HOL/IMP: updated and converted to new-style theory format; several
  4584 parts turned into readable document, with proper Isar proof texts and
  4585 some explanations (by Gerwin Klein);
  4586 
  4587 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4588 
  4589 * HOL-Hyperreal is now a logic image;
  4590 
  4591 
  4592 *** HOLCF ***
  4593 
  4594 * Isar: consts/constdefs supports mixfix syntax for continuous
  4595 operations;
  4596 
  4597 * Isar: domain package adapted to new-style theory format, e.g. see
  4598 HOLCF/ex/Dnat.thy;
  4599 
  4600 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4601 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4602 lift.induct_tac, always use UU instead of Undef;
  4603 
  4604 * HOLCF/IMP: updated and converted to new-style theory;
  4605 
  4606 
  4607 *** ZF ***
  4608 
  4609 * Isar: proper integration of logic-specific tools and packages,
  4610 including theory commands '(co)inductive', '(co)datatype',
  4611 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4612 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4613 
  4614 * theory Main no longer includes AC; for the Axiom of Choice, base
  4615 your theory on Main_ZFC;
  4616 
  4617 * the integer library now covers quotients and remainders, with many
  4618 laws relating division to addition, multiplication, etc.;
  4619 
  4620 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4621 typeless version of the formalism;
  4622 
  4623 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4624 format;
  4625 
  4626 * ZF/Induct: new directory for examples of inductive definitions,
  4627 including theory Multiset for multiset orderings; converted to
  4628 new-style theory format;
  4629 
  4630 * ZF: many new theorems about lists, ordinals, etc.;
  4631 
  4632 
  4633 *** General ***
  4634 
  4635 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4636 variable proof controls level of detail: 0 = no proofs (only oracle
  4637 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4638 also ref manual for further ML interfaces;
  4639 
  4640 * Pure/axclass: removed obsolete ML interface
  4641 goal_subclass/goal_arity;
  4642 
  4643 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4644 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4645 separate tokens, so expressions involving minus need to be spaced
  4646 properly;
  4647 
  4648 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4649 rather than "infixl" or "infixr";
  4650 
  4651 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4652 sort constraint specifications in type inference; e.g. "x::_::foo"
  4653 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4654 type variable);
  4655 
  4656 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4657 control output of nested => (types); the default behavior is
  4658 "type_brackets";
  4659 
  4660 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4661 tokens into AST constants;
  4662 
  4663 * Pure/syntax: prefer later declarations of translations and print
  4664 translation functions; potential INCOMPATIBILITY: need to reverse
  4665 multiple declarations for same syntax element constant;
  4666 
  4667 * Pure/show_hyps reset by default (in accordance to existing Isar
  4668 practice);
  4669 
  4670 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4671 addSafter;
  4672 
  4673 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4674 as well;
  4675 
  4676 * system: tested support for MacOS X; should be able to get Isabelle +
  4677 Proof General to work in a plain Terminal after installing Poly/ML
  4678 (e.g. from the Isabelle distribution area) and GNU bash alone
  4679 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4680 support requires further installations, e.g. from
  4681 http://fink.sourceforge.net/);
  4682 
  4683 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4684 
  4685 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4686 of 40 MB), cf. ML_OPTIONS;
  4687 
  4688 * system: Proof General keywords specification is now part of the
  4689 Isabelle distribution (see etc/isar-keywords.el);
  4690 
  4691 * system: support for persistent Proof General sessions (refrain from
  4692 outdating all loaded theories on startup); user may create writable
  4693 logic images like this: ``isabelle -q HOL Test'';
  4694 
  4695 * system: smart selection of Isabelle process versus Isabelle
  4696 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4697 run both "isabelle" and "Isabelle" even if file names are badly
  4698 damaged (executable inspects the case of the first letter of its own
  4699 name); added separate "isabelle-process" and "isabelle-interface";
  4700 
  4701 * system: refrain from any attempt at filtering input streams; no
  4702 longer support ``8bit'' encoding of old isabelle font, instead proper
  4703 iso-latin characters may now be used; the related isatools
  4704 "symbolinput" and "nonascii" have disappeared as well;
  4705 
  4706 * system: removed old "xterm" interface (the print modes "xterm" and
  4707 "xterm_color" are still available for direct use in a suitable
  4708 terminal);
  4709 
  4710 
  4711 
  4712 New in Isabelle99-2 (February 2001)
  4713 -----------------------------------
  4714 
  4715 *** Overview of INCOMPATIBILITIES ***
  4716 
  4717 * HOL: please note that theories in the Library and elsewhere often use the
  4718 new-style (Isar) format; to refer to their theorems in an ML script you must
  4719 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4720 
  4721 * HOL: inductive package no longer splits induction rule aggressively,
  4722 but only as far as specified by the introductions given; the old
  4723 format may be recovered via ML function complete_split_rule or attribute
  4724 'split_rule (complete)';
  4725 
  4726 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4727 gfp_Tarski to gfp_unfold;
  4728 
  4729 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4730 
  4731 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4732 relation); infix "^^" has been renamed "``"; infix "``" has been
  4733 renamed "`"; "univalent" has been renamed "single_valued";
  4734 
  4735 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4736 operation;
  4737 
  4738 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4739 
  4740 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4741 
  4742 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4743 consequence, it is no longer monotonic wrt. the local goal context
  4744 (which is now passed through the inductive cases);
  4745 
  4746 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4747 \<gg> to \<ggreater>;
  4748 
  4749 
  4750 *** Document preparation ***
  4751 
  4752 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4753 available: are "it" for near math-mode best-style output, "sl" for
  4754 slanted text style, and "tt" for plain type-writer; if no
  4755 \isabellestyle command is given, output is according to slanted
  4756 type-writer);
  4757 
  4758 * support sub/super scripts (for single symbols only), input syntax is
  4759 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4760 
  4761 * some more standard symbols; see Appendix A of the system manual for
  4762 the complete list of symbols defined in isabellesym.sty;
  4763 
  4764 * improved isabelle style files; more abstract symbol implementation
  4765 (should now use \isamath{...} and \isatext{...} in custom symbol
  4766 definitions);
  4767 
  4768 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4769 state; Note that presentation of goal states does not conform to
  4770 actual human-readable proof documents.  Please do not include goal
  4771 states into document output unless you really know what you are doing!
  4772 
  4773 * proper indentation of antiquoted output with proportional LaTeX
  4774 fonts;
  4775 
  4776 * no_document ML operator temporarily disables LaTeX document
  4777 generation;
  4778 
  4779 * isatool unsymbolize tunes sources for plain ASCII communication;
  4780 
  4781 
  4782 *** Isar ***
  4783 
  4784 * Pure: Isar now suffers initial goal statements to contain unbound
  4785 schematic variables (this does not conform to actual readable proof
  4786 documents, due to unpredictable outcome and non-compositional proof
  4787 checking); users who know what they are doing may use schematic goals
  4788 for Prolog-style synthesis of proven results;
  4789 
  4790 * Pure: assumption method (an implicit finishing) now handles actual
  4791 rules as well;
  4792 
  4793 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4794 initial goal, declare "that" only as Pure intro (only for single
  4795 steps); the "that" rule assumption may now be involved in implicit
  4796 finishing, thus ".." becomes a feasible for trivial obtains;
  4797 
  4798 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4799 instance proofs may be performed by "..";
  4800 
  4801 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4802 statements as well;
  4803 
  4804 * Pure: more robust selection of calculational rules;
  4805 
  4806 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4807 rule (as well as the assumption rule);
  4808 
  4809 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4810 lemmas, using the graph browser tool;
  4811 
  4812 * Pure: predict failure of "show" in interactive mode;
  4813 
  4814 * Pure: 'thms_containing' now takes actual terms as arguments;
  4815 
  4816 * HOL: improved method 'induct' --- now handles non-atomic goals
  4817 (potential INCOMPATIBILITY); tuned error handling;
  4818 
  4819 * HOL: cases and induct rules now provide explicit hints about the
  4820 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4821 any remaining facts are inserted into the goal verbatim;
  4822 
  4823 * HOL: local contexts (aka cases) may now contain term bindings as
  4824 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4825 the result to be shown in each case;
  4826 
  4827 * HOL: added 'recdef_tc' command;
  4828 
  4829 * isatool convert assists in eliminating legacy ML scripts;
  4830 
  4831 
  4832 *** HOL ***
  4833 
  4834 * HOL/Library: a collection of generic theories to be used together
  4835 with main HOL; the theory loader path already includes this directory
  4836 by default; the following existing theories have been moved here:
  4837 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4838 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4839 
  4840 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4841 modelling and verification task performed in Isabelle/HOL +
  4842 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4843 
  4844 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4845 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4846 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4847 'domain', this makes the theory consistent with mathematical
  4848 literature;
  4849 
  4850 * HOL basics: added overloaded operations "inverse" and "divide"
  4851 (infix "/"), syntax for generic "abs" operation, generic summation
  4852 operator \<Sum>;
  4853 
  4854 * HOL/typedef: simplified package, provide more useful rules (see also
  4855 HOL/subset.thy);
  4856 
  4857 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4858 now expressed as a proper nested rule (old-style tactic scripts may
  4859 require atomize_strip_tac to cope with non-atomic premises);
  4860 
  4861 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4862 to "split_conv" (old name still available for compatibility);
  4863 
  4864 * HOL: improved concrete syntax for strings (e.g. allows translation
  4865 rules with string literals);
  4866 
  4867 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4868  and Fleuriot's mechanization of analysis, including the transcendental
  4869  functions for the reals;
  4870 
  4871 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4872 
  4873 
  4874 *** CTT ***
  4875 
  4876 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4877 "lam" is displayed as TWO lambda-symbols
  4878 
  4879 * CTT: theory Main now available, containing everything (that is, Bool
  4880 and Arith);
  4881 
  4882 
  4883 *** General ***
  4884 
  4885 * Pure: the Simplifier has been implemented properly as a derived rule
  4886 outside of the actual kernel (at last!); the overall performance
  4887 penalty in practical applications is about 50%, while reliability of
  4888 the Isabelle inference kernel has been greatly improved;
  4889 
  4890 * print modes "brackets" and "no_brackets" control output of nested =>
  4891 (types) and ==> (props); the default behaviour is "brackets";
  4892 
  4893 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4894 as assumptions as well;
  4895 
  4896 * system: support Poly/ML 4.0;
  4897 
  4898 * system: isatool install handles KDE version 1 or 2;
  4899 
  4900 
  4901 
  4902 New in Isabelle99-1 (October 2000)
  4903 ----------------------------------
  4904 
  4905 *** Overview of INCOMPATIBILITIES ***
  4906 
  4907 * HOL: simplification of natural numbers is much changed; to partly
  4908 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4909 issue the following ML commands:
  4910 
  4911   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4912   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4913 
  4914 * HOL: simplification no longer dives into case-expressions; this is
  4915 controlled by "t.weak_case_cong" for each datatype t;
  4916 
  4917 * HOL: nat_less_induct renamed to less_induct;
  4918 
  4919 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4920 fixsome to patch .thy and .ML sources automatically;
  4921 
  4922   select_equality  -> some_equality
  4923   select_eq_Ex     -> some_eq_ex
  4924   selectI2EX       -> someI2_ex
  4925   selectI2         -> someI2
  4926   selectI          -> someI
  4927   select1_equality -> some1_equality
  4928   Eps_sym_eq       -> some_sym_eq_trivial
  4929   Eps_eq           -> some_eq_trivial
  4930 
  4931 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4932 
  4933 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4934 instead);
  4935 
  4936 * HOL: the recursion equations generated by 'recdef' are now called
  4937 f.simps instead of f.rules;
  4938 
  4939 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4940 
  4941 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4942 sometimes be needed;
  4943 
  4944 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4945 
  4946 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  4947 
  4948 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  4949 product is now "<*>" instead of "Times"; the lexicographic product is
  4950 now "<*lex*>" instead of "**";
  4951 
  4952 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  4953 of main HOL, but was unused); better use HOL's datatype package;
  4954 
  4955 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  4956 the old syntax may be recovered as follows:
  4957 
  4958   syntax (symbols)
  4959     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  4960       (infixl "\\<oplus>" 100)
  4961 
  4962 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  4963 
  4964 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  4965 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  4966 internally;
  4967 
  4968 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  4969 changed from A/r to A//r;
  4970 
  4971 * ZF: new treatment of arithmetic (nat & int) may break some old
  4972 proofs;
  4973 
  4974 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  4975 rulify -> rule_format, elimify -> elim_format, ...);
  4976 
  4977 * Isar/Provers: intro/elim/dest attributes changed; renamed
  4978 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  4979 should have to change intro!! to intro? only); replaced "delrule" by
  4980 "rule del";
  4981 
  4982 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  4983 
  4984 * Provers: strengthened force_tac by using new first_best_tac;
  4985 
  4986 * LaTeX document preparation: several changes of isabelle.sty (see
  4987 lib/texinputs);
  4988 
  4989 
  4990 *** Document preparation ***
  4991 
  4992 * formal comments (text blocks etc.) in new-style theories may now
  4993 contain antiquotations of thm/prop/term/typ/text to be presented
  4994 according to latex print mode; concrete syntax is like this:
  4995 @{term[show_types] "f(x) = a + x"};
  4996 
  4997 * isatool mkdir provides easy setup of Isabelle session directories,
  4998 including proper document sources;
  4999 
  5000 * generated LaTeX sources are now deleted after successful run
  5001 (isatool document -c); may retain a copy somewhere else via -D option
  5002 of isatool usedir;
  5003 
  5004 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5005 style files, achieving self-contained LaTeX sources and simplifying
  5006 LaTeX debugging;
  5007 
  5008 * old-style theories now produce (crude) LaTeX output as well;
  5009 
  5010 * browser info session directories are now self-contained (may be put
  5011 on WWW server seperately); improved graphs of nested sessions; removed
  5012 graph for 'all sessions';
  5013 
  5014 * several improvements in isabelle style files; \isabellestyle{it}
  5015 produces fake math mode output; \isamarkupheader is now \section by
  5016 default; see lib/texinputs/isabelle.sty etc.;
  5017 
  5018 
  5019 *** Isar ***
  5020 
  5021 * Isar/Pure: local results and corresponding term bindings are now
  5022 subject to Hindley-Milner polymorphism (similar to ML); this
  5023 accommodates incremental type-inference very nicely;
  5024 
  5025 * Isar/Pure: new derived language element 'obtain' supports
  5026 generalized existence reasoning;
  5027 
  5028 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5029 support accumulation of results, without applying any rules yet;
  5030 useful to collect intermediate results without explicit name
  5031 references, and for use with transitivity rules with more than 2
  5032 premises;
  5033 
  5034 * Isar/Pure: scalable support for case-analysis type proofs: new
  5035 'case' language element refers to local contexts symbolically, as
  5036 produced by certain proof methods; internally, case names are attached
  5037 to theorems as "tags";
  5038 
  5039 * Isar/Pure: theory command 'hide' removes declarations from
  5040 class/type/const name spaces;
  5041 
  5042 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5043 indicate potential overloading;
  5044 
  5045 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5046 
  5047 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5048 "{a,b,c}" instead of {a,b,c};
  5049 
  5050 * Isar/Pure now provides its own version of intro/elim/dest
  5051 attributes; useful for building new logics, but beware of confusion
  5052 with the version in Provers/classical;
  5053 
  5054 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5055 case name 'antecedent';
  5056 
  5057 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5058 to the current context is now done automatically);
  5059 
  5060 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5061 for definining proof methods in ML;
  5062 
  5063 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5064 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5065 most cases, one should have to change intro!! to intro? only);
  5066 replaced "delrule" by "rule del";
  5067 
  5068 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5069 'symmetric' attribute (the latter supercedes [RS sym]);
  5070 
  5071 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5072 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5073 well (including splits);
  5074 
  5075 * Isar/Provers: Simplifier and Classical methods now support all kind
  5076 of modifiers used in the past, including 'cong', 'iff', etc.
  5077 
  5078 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5079 of Simplifier and Classical reasoner);
  5080 
  5081 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5082 now support named cases; major packages (inductive, datatype, primrec,
  5083 recdef) support case names and properly name parameters;
  5084 
  5085 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5086 monotonicity conditions are extracted to be proven at end of
  5087 calculations;
  5088 
  5089 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5090 method anyway;
  5091 
  5092 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5093 split_if split_if_asm; datatype package provides theorems foo.splits =
  5094 foo.split foo.split_asm for each datatype;
  5095 
  5096 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5097 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5098 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5099 use "(cases (simplified))" method in proper proof texts);
  5100 
  5101 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5102 
  5103 * Isar: names of theorems etc. may be natural numbers as well;
  5104 
  5105 * Isar: 'pr' command: optional arguments for goals_limit and
  5106 ProofContext.prems_limit; no longer prints theory contexts, but only
  5107 proof states;
  5108 
  5109 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5110 additional print modes to be specified; e.g. "pr(latex)" will print
  5111 proof state according to the Isabelle LaTeX style;
  5112 
  5113 * Isar: improved support for emulating tactic scripts, including proof
  5114 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5115 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5116 (for HOL datatypes);
  5117 
  5118 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5119 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5120 'proof method scripts' have to be in depth-first order;
  5121 
  5122 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5123 
  5124 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5125 should instead use individual commands for printing items
  5126 (print_commands, print_methods etc.);
  5127 
  5128 * Isar: added 'nothing' --- the empty list of theorems;
  5129 
  5130 
  5131 *** HOL ***
  5132 
  5133 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5134 corresponding virtual machine and a specification of its bytecode
  5135 verifier and a lightweight bytecode verifier, including proofs of
  5136 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5137 Cornelia Pusch (see also the homepage of project Bali at
  5138 http://isabelle.in.tum.de/Bali/);
  5139 
  5140 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5141 Clemens Ballarin;
  5142 
  5143 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5144 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5145 Rasmussen;
  5146 
  5147 * HOL/Lattice: fundamental concepts of lattice theory and order
  5148 structures, including duals, properties of bounds versus algebraic
  5149 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5150 Theorem for complete lattices etc.; may also serve as a demonstration
  5151 for abstract algebraic reasoning using axiomatic type classes, and
  5152 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5153 
  5154 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5155 von Oheimb;
  5156 
  5157 * HOL/IMPP: extension of IMP with local variables and mutually
  5158 recursive procedures, by David von Oheimb;
  5159 
  5160 * HOL/Lambda: converted into new-style theory and document;
  5161 
  5162 * HOL/ex/Multiquote: example of multiple nested quotations and
  5163 anti-quotations -- basically a generalized version of de-Bruijn
  5164 representation; very useful in avoiding lifting of operations;
  5165 
  5166 * HOL/record: added general record equality rule to simpset; fixed
  5167 select-update simplification procedure to handle extended records as
  5168 well; admit "r" as field name;
  5169 
  5170 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5171 other numeric types and also as the identity of groups, rings, etc.;
  5172 
  5173 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5174 Types nat and int belong to this axclass;
  5175 
  5176 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5177    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5178    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5179   two terms #m*u and #n*u are replaced by #(m+n)*u
  5180     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5181   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5182     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5183 
  5184 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5185 powerful prover for predicate logic but knows nothing of clasets; see
  5186 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5187 
  5188 * HOL: new version of "case_tac" subsumes both boolean case split and
  5189 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5190 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5191 
  5192 * HOL: simplification no longer dives into case-expressions: only the
  5193 selector expression is simplified, but not the remaining arms; to
  5194 enable full simplification of case-expressions for datatype t, you may
  5195 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5196 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5197 
  5198 * HOL/recdef: the recursion equations generated by 'recdef' for
  5199 function 'f' are now called f.simps instead of f.rules; if all
  5200 termination conditions are proved automatically, these simplification
  5201 rules are added to the simpset, as in primrec; rules may be named
  5202 individually as well, resulting in a separate list of theorems for
  5203 each equation;
  5204 
  5205 * HOL/While is a new theory that provides a while-combinator. It
  5206 permits the definition of tail-recursive functions without the
  5207 provision of a termination measure. The latter is necessary once the
  5208 invariant proof rule for while is applied.
  5209 
  5210 * HOL: new (overloaded) notation for the set of elements below/above
  5211 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5212 
  5213 * HOL: theorems impI, allI, ballI bound as "strip";
  5214 
  5215 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5216 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5217 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5218 
  5219 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5220 
  5221 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5222 main HOL, but was unused);
  5223 
  5224 * HOL: fewer consts declared as global (e.g. have to refer to
  5225 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5226 
  5227 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5228 in case of overlap with user translations (e.g. judgements over
  5229 tuples); (note that the underlying logical represenation is still
  5230 bogus);
  5231 
  5232 
  5233 *** ZF ***
  5234 
  5235 * ZF: simplification automatically cancels common terms in arithmetic
  5236 expressions over nat and int;
  5237 
  5238 * ZF: new treatment of nat to minimize type-checking: all operators
  5239 coerce their operands to a natural number using the function natify,
  5240 making the algebraic laws unconditional;
  5241 
  5242 * ZF: as above, for int: operators coerce their operands to an integer
  5243 using the function intify;
  5244 
  5245 * ZF: the integer library now contains many of the usual laws for the
  5246 orderings, including $<=, and monotonicity laws for $+ and $*;
  5247 
  5248 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5249 simplification;
  5250 
  5251 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5252 to the simplifier and classical reasoner simultaneously;
  5253 
  5254 
  5255 *** General ***
  5256 
  5257 * Provers: blast_tac now handles actual object-logic rules as
  5258 assumptions; note that auto_tac uses blast_tac internally as well;
  5259 
  5260 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5261 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5262 
  5263 * Provers: delrules now handles destruct rules as well (no longer need
  5264 explicit make_elim);
  5265 
  5266 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5267   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5268 use instead the strong form,
  5269   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5270 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5271 from destruct-rules;
  5272 
  5273 * Provers: Simplifier.easy_setup provides a fast path to basic
  5274 Simplifier setup for new object-logics;
  5275 
  5276 * Pure: AST translation rules no longer require constant head on LHS;
  5277 
  5278 * Pure: improved name spaces: ambiguous output is qualified; support
  5279 for hiding of names;
  5280 
  5281 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5282 XSYMBOL_HOME; no longer need to do manual configuration in most
  5283 situations;
  5284 
  5285 * system: compression of ML heaps images may now be controlled via -c
  5286 option of isabelle and isatool usedir (currently only observed by
  5287 Poly/ML);
  5288 
  5289 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5290 useful for remote X11);
  5291 
  5292 * system: provide TAGS file for Isabelle sources;
  5293 
  5294 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5295 order;
  5296 
  5297 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5298 timing flag supersedes proof_timing and Toplevel.trace;
  5299 
  5300 * ML: new combinators |>> and |>>> for incremental transformations
  5301 with secondary results (e.g. certain theory extensions):
  5302 
  5303 * ML: PureThy.add_defs gets additional argument to indicate potential
  5304 overloading (usually false);
  5305 
  5306 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5307 results;
  5308 
  5309 
  5310 
  5311 New in Isabelle99 (October 1999)
  5312 --------------------------------
  5313 
  5314 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5315 
  5316 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5317 are no longer simplified.  (This allows the simplifier to unfold recursive
  5318 functional programs.)  To restore the old behaviour, declare
  5319 
  5320     Delcongs [if_weak_cong];
  5321 
  5322 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5323 complement;
  5324 
  5325 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5326 
  5327 * HOL/datatype: mutual_induct_tac no longer exists --
  5328   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5329 
  5330 * HOL/typedef: fixed type inference for representing set; type
  5331 arguments now have to occur explicitly on the rhs as type constraints;
  5332 
  5333 * ZF: The con_defs part of an inductive definition may no longer refer
  5334 to constants declared in the same theory;
  5335 
  5336 * HOL, ZF: the function mk_cases, generated by the inductive
  5337 definition package, has lost an argument.  To simplify its result, it
  5338 uses the default simpset instead of a supplied list of theorems.
  5339 
  5340 * HOL/List: the constructors of type list are now Nil and Cons;
  5341 
  5342 * Simplifier: the type of the infix ML functions
  5343         setSSolver addSSolver setSolver addSolver
  5344 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5345 for packaging solvers. A solver is created via
  5346         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5347 where the string argument is only a comment.
  5348 
  5349 
  5350 *** Proof tools ***
  5351 
  5352 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5353 decision procedure for linear arithmetic. Currently it is used for
  5354 types `nat', `int', and `real' in HOL (see below); it can, should and
  5355 will be instantiated for other types and logics as well.
  5356 
  5357 * The simplifier now accepts rewrite rules with flexible heads, eg
  5358      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5359   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5360   matching.
  5361 
  5362 
  5363 *** General ***
  5364 
  5365 * New Isabelle/Isar subsystem provides an alternative to traditional
  5366 tactical theorem proving; together with the ProofGeneral/isar user
  5367 interface it offers an interactive environment for developing human
  5368 readable proof documents (Isar == Intelligible semi-automated
  5369 reasoning); for further information see isatool doc isar-ref,
  5370 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5371 
  5372 * improved and simplified presentation of theories: better HTML markup
  5373 (including colors), graph views in several sizes; isatool usedir now
  5374 provides a proper interface for user theories (via -P option); actual
  5375 document preparation based on (PDF)LaTeX is available as well (for
  5376 new-style theories only); see isatool doc system for more information;
  5377 
  5378 * native support for Proof General, both for classic Isabelle and
  5379 Isabelle/Isar;
  5380 
  5381 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5382 using the graph browser tool;
  5383 
  5384 * Isabelle manuals now also available as PDF;
  5385 
  5386 * theory loader rewritten from scratch (may not be fully
  5387 bug-compatible); old loadpath variable has been replaced by show_path,
  5388 add_path, del_path, reset_path functions; new operations such as
  5389 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5390 isatool doc ref);
  5391 
  5392 * improved isatool install: option -k creates KDE application icon,
  5393 option -p DIR installs standalone binaries;
  5394 
  5395 * added ML_PLATFORM setting (useful for cross-platform installations);
  5396 more robust handling of platform specific ML images for SML/NJ;
  5397 
  5398 * the settings environment is now statically scoped, i.e. it is never
  5399 created again in sub-processes invoked from isabelle, isatool, or
  5400 Isabelle;
  5401 
  5402 * path element specification '~~' refers to '$ISABELLE_HOME';
  5403 
  5404 * in locales, the "assumes" and "defines" parts may be omitted if
  5405 empty;
  5406 
  5407 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5408 long arrows);
  5409 
  5410 * new print_mode "HTML";
  5411 
  5412 * new flag show_tags controls display of tags of theorems (which are
  5413 basically just comments that may be attached by some tools);
  5414 
  5415 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5416 mode and goal output format:
  5417 
  5418 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5419 244c244
  5420 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5421 ---
  5422 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5423 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5424 181c181
  5425 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5426 ---
  5427 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5428 
  5429 * function bind_thms stores lists of theorems (cf. bind_thm);
  5430 
  5431 * new shorthand tactics ftac, eatac, datac, fatac;
  5432 
  5433 * qed (and friends) now accept "" as result name; in that case the
  5434 theorem is not stored, but proper checks and presentation of the
  5435 result still apply;
  5436 
  5437 * theorem database now also indexes constants "Trueprop", "all",
  5438 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5439 
  5440 
  5441 *** HOL ***
  5442 
  5443 ** HOL arithmetic **
  5444 
  5445 * There are now decision procedures for linear arithmetic over nat and
  5446 int:
  5447 
  5448 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5449 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5450 are treated as atomic; subformulae not involving type `nat' or `int'
  5451 are ignored; quantified subformulae are ignored unless they are
  5452 positive universal or negative existential. The tactic has to be
  5453 invoked by hand and can be a little bit slow. In particular, the
  5454 running time is exponential in the number of occurrences of `min' and
  5455 `max', and `-' on `nat'.
  5456 
  5457 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5458 (negated) (in)equalities among the premises and the conclusion into
  5459 account (i.e. no compound formulae) and does not know about `min' and
  5460 `max', and `-' on `nat'. It is fast and is used automatically by the
  5461 simplifier.
  5462 
  5463 NB: At the moment, these decision procedures do not cope with mixed
  5464 nat/int formulae where the two parts interact, such as `m < n ==>
  5465 int(m) < int(n)'.
  5466 
  5467 * HOL/Numeral provides a generic theory of numerals (encoded
  5468 efficiently as bit strings); setup for types nat/int/real is in place;
  5469 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5470 int, existing theories and proof scripts may require a few additional
  5471 type constraints;
  5472 
  5473 * integer division and remainder can now be performed on constant
  5474 arguments;
  5475 
  5476 * many properties of integer multiplication, division and remainder
  5477 are now available;
  5478 
  5479 * An interface to the Stanford Validity Checker (SVC) is available through the
  5480 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5481 are proved automatically.  SVC must be installed separately, and its results
  5482 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5483 invocation of the underlying oracle).  For SVC see
  5484   http://verify.stanford.edu/SVC
  5485 
  5486 * IsaMakefile: the HOL-Real target now builds an actual image;
  5487 
  5488 
  5489 ** HOL misc **
  5490 
  5491 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5492 (in Isabelle/Isar) -- by Gertrud Bauer;
  5493 
  5494 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5495 analysis for assembly languages with subtypes;
  5496 
  5497 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5498 -- avoids syntactic ambiguities and treats state, transition, and
  5499 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5500 changed syntax and (many) tactics;
  5501 
  5502 * HOL/inductive: Now also handles more general introduction rules such
  5503   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5504   theorems are now maintained within the theory (maintained via the
  5505   "mono" attribute);
  5506 
  5507 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5508   (using function types) such as
  5509 
  5510   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5511 
  5512 * HOL/record: record_simproc (part of the default simpset) takes care
  5513 of selectors applied to updated records; record_split_tac is no longer
  5514 part of the default claset; update_defs may now be removed from the
  5515 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5516 
  5517   claset_ref () := claset() addSWrapper record_split_wrapper;
  5518   Delsimprocs [record_simproc]
  5519 
  5520 * HOL/typedef: fixed type inference for representing set; type
  5521 arguments now have to occur explicitly on the rhs as type constraints;
  5522 
  5523 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5524 names rather than an ML expression;
  5525 
  5526 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5527 supplied later.  Program schemes can be defined, such as
  5528     "While B C s = (if B s then While B C (C s) else s)"
  5529 where the well-founded relation can be chosen after B and C have been given.
  5530 
  5531 * HOL/List: the constructors of type list are now Nil and Cons;
  5532 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5533 course, ML tools referring to List.list.op # etc. have to be adapted;
  5534 
  5535 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5536 disabled by default; run isabelle with option -m HOL to get back to
  5537 the original Gordon/HOL-style output;
  5538 
  5539 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5540 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5541 
  5542 * HOL basic syntax simplified (more orthogonal): all variants of
  5543 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5544 Eps operator is provided as well: "SOME x. P[x]";
  5545 
  5546 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5547 
  5548 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5549 thus available for user theories;
  5550 
  5551 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5552 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5553 time;
  5554 
  5555 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5556 several times and then mp;
  5557 
  5558 
  5559 *** LK ***
  5560 
  5561 * the notation <<...>> is now available as a notation for sequences of
  5562 formulas;
  5563 
  5564 * the simplifier is now installed
  5565 
  5566 * the axiom system has been generalized (thanks to Soren Heilmann)
  5567 
  5568 * the classical reasoner now has a default rule database
  5569 
  5570 
  5571 *** ZF ***
  5572 
  5573 * new primrec section allows primitive recursive functions to be given
  5574 directly (as in HOL) over datatypes and the natural numbers;
  5575 
  5576 * new tactics induct_tac and exhaust_tac for induction (or case
  5577 analysis) over datatypes and the natural numbers;
  5578 
  5579 * the datatype declaration of type T now defines the recursor T_rec;
  5580 
  5581 * simplification automatically does freeness reasoning for datatype
  5582 constructors;
  5583 
  5584 * automatic type-inference, with AddTCs command to insert new
  5585 type-checking rules;
  5586 
  5587 * datatype introduction rules are now added as Safe Introduction rules
  5588 to the claset;
  5589 
  5590 * the syntax "if P then x else y" is now available in addition to
  5591 if(P,x,y);
  5592 
  5593 
  5594 *** Internal programming interfaces ***
  5595 
  5596 * tuned simplifier trace output; new flag debug_simp;
  5597 
  5598 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5599 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5600 
  5601 * AxClass.axclass_tac lost the theory argument;
  5602 
  5603 * tuned current_goals_markers semantics: begin / end goal avoids
  5604 printing empty lines;
  5605 
  5606 * removed prs and prs_fn hook, which was broken because it did not
  5607 include \n in its semantics, forcing writeln to add one
  5608 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5609 string -> unit if you really want to output text without newline;
  5610 
  5611 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5612 plain output, interface builders may have to enable 'isabelle_font'
  5613 mode to get Isabelle font glyphs as before;
  5614 
  5615 * refined token_translation interface; INCOMPATIBILITY: output length
  5616 now of type real instead of int;
  5617 
  5618 * theory loader actions may be traced via new ThyInfo.add_hook
  5619 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5620 your own database of information attached to *whole* theories -- as
  5621 opposed to intra-theory data slots offered via TheoryDataFun;
  5622 
  5623 * proper handling of dangling sort hypotheses (at last!);
  5624 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5625 extra sort hypotheses that can be witnessed from the type signature;
  5626 the force_strip_shyps flag is gone, any remaining shyps are simply
  5627 left in the theorem (with a warning issued by strip_shyps_warning);
  5628 
  5629 
  5630 
  5631 New in Isabelle98-1 (October 1998)
  5632 ----------------------------------
  5633 
  5634 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5635 
  5636 * several changes of automated proof tools;
  5637 
  5638 * HOL: major changes to the inductive and datatype packages, including
  5639 some minor incompatibilities of theory syntax;
  5640 
  5641 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5642 called `inj_on';
  5643 
  5644 * HOL: removed duplicate thms in Arith:
  5645   less_imp_add_less  should be replaced by  trans_less_add1
  5646   le_imp_add_le      should be replaced by  trans_le_add1
  5647 
  5648 * HOL: unary minus is now overloaded (new type constraints may be
  5649 required);
  5650 
  5651 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5652 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5653 now taken as an integer constant.
  5654 
  5655 * Pure: ML function 'theory_of' renamed to 'theory';
  5656 
  5657 
  5658 *** Proof tools ***
  5659 
  5660 * Simplifier:
  5661   1. Asm_full_simp_tac is now more aggressive.
  5662      1. It will sometimes reorient premises if that increases their power to
  5663         simplify.
  5664      2. It does no longer proceed strictly from left to right but may also
  5665         rotate premises to achieve further simplification.
  5666      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5667      old Asm_full_simp_tac in that it does not rotate premises.
  5668   2. The simplifier now knows a little bit about nat-arithmetic.
  5669 
  5670 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5671 allows for selected deletion of wrappers, by introduction of names for
  5672 wrapper functionals.  This implies that addbefore, addSbefore,
  5673 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5674 and that adding two tactics with the same name overwrites the first
  5675 one (emitting a warning).
  5676   type wrapper = (int -> tactic) -> (int -> tactic)
  5677   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5678   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5679   delWrapper, delSWrapper: claset *  string            -> claset
  5680   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5681 
  5682 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5683 semantics; addbefore now affects only the unsafe part of step_tac
  5684 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5685 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5686 by Force_tac;
  5687 
  5688 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5689 compWrapper; added safe wrapper (and access functions for it);
  5690 
  5691 * HOL/split_all_tac is now much faster and fails if there is nothing
  5692 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5693 and the names of the automatically generated variables have changed.
  5694 split_all_tac has moved within claset() from unsafe wrappers to safe
  5695 wrappers, which means that !!-bound variables are split much more
  5696 aggressively, and safe_tac and clarify_tac now split such variables.
  5697 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5698 Note: the same holds for record_split_tac, which does the job of
  5699 split_all_tac for record fields.
  5700 
  5701 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5702 permanently to the default simpset using Addsplits just like
  5703 Addsimps. They can be removed via Delsplits just like
  5704 Delsimps. Lower-case versions are also available.
  5705 
  5706 * HOL/Simplifier: The rule split_if is now part of the default
  5707 simpset. This means that the simplifier will eliminate all occurrences
  5708 of if-then-else in the conclusion of a goal. To prevent this, you can
  5709 either remove split_if completely from the default simpset by
  5710 `Delsplits [split_if]' or remove it in a specific call of the
  5711 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5712 other case splitting rules to/from the default simpset: every datatype
  5713 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5714 t is the name of the datatype).
  5715 
  5716 * Classical reasoner / Simplifier combination: new force_tac (and
  5717 derivatives Force_tac, force) combines rewriting and classical
  5718 reasoning (and whatever other tools) similarly to auto_tac, but is
  5719 aimed to solve the given subgoal completely.
  5720 
  5721 
  5722 *** General ***
  5723 
  5724 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5725 and `goalw': the theory is no longer needed as an explicit argument -
  5726 the current theory context is used; assumptions are no longer returned
  5727 at the ML-level unless one of them starts with ==> or !!; it is
  5728 recommended to convert to these new commands using isatool fixgoal
  5729 (backup your sources first!);
  5730 
  5731 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5732 the current theory context, and 'theory' to lookup stored theories;
  5733 
  5734 * new theory section 'locale' for declaring constants, assumptions and
  5735 definitions that have local scope;
  5736 
  5737 * new theory section 'nonterminals' for purely syntactic types;
  5738 
  5739 * new theory section 'setup' for generic ML setup functions
  5740 (e.g. package initialization);
  5741 
  5742 * the distribution now includes Isabelle icons: see
  5743 lib/logo/isabelle-{small,tiny}.xpm;
  5744 
  5745 * isatool install - install binaries with absolute references to
  5746 ISABELLE_HOME/bin;
  5747 
  5748 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5749 
  5750 * print mode 'emacs' reserved for Isamode;
  5751 
  5752 * support multiple print (ast) translations per constant name;
  5753 
  5754 * theorems involving oracles are now printed with a suffixed [!];
  5755 
  5756 
  5757 *** HOL ***
  5758 
  5759 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5760 
  5761 * HOL/inductive package reorganized and improved: now supports mutual
  5762 definitions such as
  5763 
  5764   inductive EVEN ODD
  5765     intrs
  5766       null "0 : EVEN"
  5767       oddI "n : EVEN ==> Suc n : ODD"
  5768       evenI "n : ODD ==> Suc n : EVEN"
  5769 
  5770 new theorem list "elims" contains an elimination rule for each of the
  5771 recursive sets; inductive definitions now handle disjunctive premises
  5772 correctly (also ZF);
  5773 
  5774 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5775 "mutual_induct" no longer exists - the induction rule is always
  5776 contained in "induct";
  5777 
  5778 
  5779 * HOL/datatype package re-implemented and greatly improved: now
  5780 supports mutually recursive datatypes such as
  5781 
  5782   datatype
  5783     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5784             | SUM ('a aexp) ('a aexp)
  5785             | DIFF ('a aexp) ('a aexp)
  5786             | NUM 'a
  5787   and
  5788     'a bexp = LESS ('a aexp) ('a aexp)
  5789             | AND ('a bexp) ('a bexp)
  5790             | OR ('a bexp) ('a bexp)
  5791 
  5792 as well as indirectly recursive datatypes such as
  5793 
  5794   datatype
  5795     ('a, 'b) term = Var 'a
  5796                   | App 'b ((('a, 'b) term) list)
  5797 
  5798 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5799 induction on mutually / indirectly recursive datatypes.
  5800 
  5801 Primrec equations are now stored in theory and can be accessed via
  5802 <function_name>.simps.
  5803 
  5804 INCOMPATIBILITIES:
  5805 
  5806   - Theories using datatypes must now have theory Datatype as an
  5807     ancestor.
  5808   - The specific <typename>.induct_tac no longer exists - use the
  5809     generic induct_tac instead.
  5810   - natE has been renamed to nat.exhaust - use exhaust_tac
  5811     instead of res_inst_tac ... natE. Note that the variable
  5812     names in nat.exhaust differ from the names in natE, this
  5813     may cause some "fragile" proofs to fail.
  5814   - The theorems split_<typename>_case and split_<typename>_case_asm
  5815     have been renamed to <typename>.split and <typename>.split_asm.
  5816   - Since default sorts of type variables are now handled correctly,
  5817     some datatype definitions may have to be annotated with explicit
  5818     sort constraints.
  5819   - Primrec definitions no longer require function name and type
  5820     of recursive argument.
  5821 
  5822 Consider using isatool fixdatatype to adapt your theories and proof
  5823 scripts to the new package (backup your sources first!).
  5824 
  5825 
  5826 * HOL/record package: considerably improved implementation; now
  5827 includes concrete syntax for record types, terms, updates; theorems
  5828 for surjective pairing and splitting !!-bound record variables; proof
  5829 support is as follows:
  5830 
  5831   1) standard conversions (selectors or updates applied to record
  5832 constructor terms) are part of the standard simpset;
  5833 
  5834   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5835 made part of standard simpset and claset via addIffs;
  5836 
  5837   3) a tactic for record field splitting (record_split_tac) is part of
  5838 the standard claset (addSWrapper);
  5839 
  5840 To get a better idea about these rules you may retrieve them via
  5841 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5842 the name of your record type.
  5843 
  5844 The split tactic 3) conceptually simplifies by the following rule:
  5845 
  5846   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5847 
  5848 Thus any record variable that is bound by meta-all will automatically
  5849 blow up into some record constructor term, consequently the
  5850 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5851 solve record problems automatically.
  5852 
  5853 
  5854 * reorganized the main HOL image: HOL/Integ and String loaded by
  5855 default; theory Main includes everything;
  5856 
  5857 * automatic simplification of integer sums and comparisons, using cancellation;
  5858 
  5859 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5860 
  5861 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5862 
  5863 * many new identities for unions, intersections, set difference, etc.;
  5864 
  5865 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5866 called split_if, split_split, split_sum_case and split_nat_case (to go
  5867 with add/delsplits);
  5868 
  5869 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5870 (?x::unit) = (); this is made part of the default simpset, which COULD
  5871 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5872 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5873 unit_abs_eta_conv is added in order to counter the effect of
  5874 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5875 %u.f();
  5876 
  5877 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5878 makes more sense);
  5879 
  5880 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5881   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5882   disjointness reasoning but breaking a few old proofs.
  5883 
  5884 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5885 to 'converse' from 'inverse' (for compatibility with ZF and some
  5886 literature);
  5887 
  5888 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5889 the well-founded relation;
  5890 
  5891 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5892     Compl A.  The "Compl" syntax remains available as input syntax for this
  5893     release ONLY.
  5894 
  5895 * HOL/Update: new theory of function updates:
  5896     f(a:=b) == %x. if x=a then b else f x
  5897 may also be iterated as in f(a:=b,c:=d,...);
  5898 
  5899 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5900 
  5901 * HOL/List:
  5902   - new function list_update written xs[i:=v] that updates the i-th
  5903     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5904   - new function `upt' written [i..j(] which generates the list
  5905     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5906     bound write [i..j], which is a shorthand for [i..j+1(].
  5907   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5908 
  5909 * HOL/Arith:
  5910   - removed 'pred' (predecessor) function;
  5911   - generalized some theorems about n-1;
  5912   - many new laws about "div" and "mod";
  5913   - new laws about greatest common divisors (see theory ex/Primes);
  5914 
  5915 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5916 instead of "inverse";
  5917 
  5918 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5919   of the multiset ordering;
  5920 
  5921 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5922   (not included by default);
  5923 
  5924 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5925 
  5926 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5927   programs, i.e. different program variables may have different types.
  5928 
  5929 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5930   [previously, this check worked only if the rewrite rule was unconditional]
  5931   Now rew can involve either definitions or equalities (either == or =).
  5932 
  5933 
  5934 *** ZF ***
  5935 
  5936 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5937   only the theorems proved on ZF.ML;
  5938 
  5939 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5940   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5941   disjointness reasoning but breaking a few old proofs.
  5942 
  5943 * ZF/Update: new theory of function updates
  5944     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5945   may also be iterated as in f(a:=b,c:=d,...);
  5946 
  5947 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  5948 
  5949 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5950   [previously, this check worked only if the rewrite rule was unconditional]
  5951   Now rew can involve either definitions or equalities (either == or =).
  5952 
  5953 * case_tac provided for compatibility with HOL
  5954     (like the old excluded_middle_tac, but with subgoals swapped)
  5955 
  5956 
  5957 *** Internal programming interfaces ***
  5958 
  5959 * Pure: several new basic modules made available for general use, see
  5960 also src/Pure/README;
  5961 
  5962 * improved the theory data mechanism to support encapsulation (data
  5963 kind name replaced by private Object.kind, acting as authorization
  5964 key); new type-safe user interface via functor TheoryDataFun; generic
  5965 print_data function becomes basically useless;
  5966 
  5967 * removed global_names compatibility flag -- all theory declarations
  5968 are qualified by default;
  5969 
  5970 * module Pure/Syntax now offers quote / antiquote translation
  5971 functions (useful for Hoare logic etc. with implicit dependencies);
  5972 see HOL/ex/Antiquote for an example use;
  5973 
  5974 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  5975 cterm -> thm;
  5976 
  5977 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  5978 subgoal;
  5979 
  5980 * Display.print_goals function moved to Locale.print_goals;
  5981 
  5982 * standard print function for goals supports current_goals_markers
  5983 variable for marking begin of proof, end of proof, start of goal; the
  5984 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  5985 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  5986 for example;
  5987 
  5988 
  5989 
  5990 New in Isabelle98 (January 1998)
  5991 --------------------------------
  5992 
  5993 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5994 
  5995 * changed lexical syntax of terms / types: dots made part of long
  5996 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  5997 
  5998 * simpset (and claset) reference variable replaced by functions
  5999 simpset / simpset_ref;
  6000 
  6001 * no longer supports theory aliases (via merge) and non-trivial
  6002 implicit merge of thms' signatures;
  6003 
  6004 * most internal names of constants changed due to qualified names;
  6005 
  6006 * changed Pure/Sequence interface (see Pure/seq.ML);
  6007 
  6008 
  6009 *** General Changes ***
  6010 
  6011 * hierachically structured name spaces (for consts, types, axms, thms
  6012 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6013 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6014 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6015 long_names for fully qualified output names; NOTE: ML programs
  6016 (special tactics, packages etc.) referring to internal names may have
  6017 to be adapted to cope with fully qualified names; in case of severe
  6018 backward campatibility problems try setting 'global_names' at compile
  6019 time to have enrything declared within a flat name space; one may also
  6020 fine tune name declarations in theories via the 'global' and 'local'
  6021 section;
  6022 
  6023 * reimplemented the implicit simpset and claset using the new anytype
  6024 data filed in signatures; references simpset:simpset ref etc. are
  6025 replaced by functions simpset:unit->simpset and
  6026 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6027 to patch your ML files accordingly;
  6028 
  6029 * HTML output now includes theory graph data for display with Java
  6030 applet or isatool browser; data generated automatically via isatool
  6031 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6032 
  6033 * defs may now be conditional; improved rewrite_goals_tac to handle
  6034 conditional equations;
  6035 
  6036 * defs now admits additional type arguments, using TYPE('a) syntax;
  6037 
  6038 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6039 creates a new theory node; implicit merge of thms' signatures is
  6040 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6041 transfer:theory->thm->thm in (rare) cases;
  6042 
  6043 * improved handling of draft signatures / theories; draft thms (and
  6044 ctyps, cterms) are automatically promoted to real ones;
  6045 
  6046 * slightly changed interfaces for oracles: admit many per theory, named
  6047 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6048 
  6049 * print_goals: optional output of const types (set show_consts and
  6050 show_types);
  6051 
  6052 * improved output of warnings (###) and errors (***);
  6053 
  6054 * subgoal_tac displays a warning if the new subgoal has type variables;
  6055 
  6056 * removed old README and Makefiles;
  6057 
  6058 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6059 
  6060 * removed obsolete init_pps and init_database;
  6061 
  6062 * deleted the obsolete tactical STATE, which was declared by
  6063     fun STATE tacfun st = tacfun st st;
  6064 
  6065 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6066 (which abbreviates $HOME);
  6067 
  6068 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6069 use isatool fixseq to adapt your ML programs (this works for fully
  6070 qualified references to the Sequence structure only!);
  6071 
  6072 * use_thy no longer requires writable current directory; it always
  6073 reloads .ML *and* .thy file, if either one is out of date;
  6074 
  6075 
  6076 *** Classical Reasoner ***
  6077 
  6078 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6079 tactics that use classical reasoning to simplify a subgoal without
  6080 splitting it into several subgoals;
  6081 
  6082 * Safe_tac: like safe_tac but uses the default claset;
  6083 
  6084 
  6085 *** Simplifier ***
  6086 
  6087 * added simplification meta rules:
  6088     (asm_)(full_)simplify: simpset -> thm -> thm;
  6089 
  6090 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6091 logics (again);
  6092 
  6093 * added prems argument to simplification procedures;
  6094 
  6095 * HOL, FOL, ZF: added infix function `addsplits':
  6096   instead of `<simpset> setloop (split_tac <thms>)'
  6097   you can simply write `<simpset> addsplits <thms>'
  6098 
  6099 
  6100 *** Syntax ***
  6101 
  6102 * TYPE('a) syntax for type reflection terms;
  6103 
  6104 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6105 
  6106 * pretty printer: changed order of mixfix annotation preference (again!);
  6107 
  6108 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6109 
  6110 
  6111 *** HOL ***
  6112 
  6113 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6114   with `addloop' of the simplifier to faciliate case splitting in premises.
  6115 
  6116 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6117 
  6118 * HOL/Auth: new protocol proofs including some for the Internet
  6119   protocol TLS;
  6120 
  6121 * HOL/Map: new theory of `maps' a la VDM;
  6122 
  6123 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6124 cancelling out common nat summands from =, <, <= (in)equalities, or
  6125 differences; simplification procedures nat_cancel_factor for
  6126 cancelling common factor from =, <, <= (in)equalities over natural
  6127 sums; nat_cancel contains both kinds of procedures, it is installed by
  6128 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6129 
  6130 * HOL/simplifier: terms of the form
  6131   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6132   are rewritten to
  6133   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6134   and those of the form
  6135   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6136   are rewritten to
  6137   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6138 
  6139 * HOL/datatype
  6140   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6141 
  6142   P(t_case f1 ... fn x) =
  6143      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6144         ...
  6145        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6146      )
  6147 
  6148   and a theorem `split_t_case_asm' of the form
  6149 
  6150   P(t_case f1 ... fn x) =
  6151     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6152         ...
  6153        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6154      )
  6155   which can be added to a simpset via `addsplits'. The existing theorems
  6156   expand_list_case and expand_option_case have been renamed to
  6157   split_list_case and split_option_case.
  6158 
  6159 * HOL/Arithmetic:
  6160   - `pred n' is automatically converted to `n-1'.
  6161     Users are strongly encouraged not to use `pred' any longer,
  6162     because it will disappear altogether at some point.
  6163   - Users are strongly encouraged to write "0 < n" rather than
  6164     "n ~= 0". Theorems and proof tools have been modified towards this
  6165     `standard'.
  6166 
  6167 * HOL/Lists:
  6168   the function "set_of_list" has been renamed "set" (and its theorems too);
  6169   the function "nth" now takes its arguments in the reverse order and
  6170   has acquired the infix notation "!" as in "xs!n".
  6171 
  6172 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6173 
  6174 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6175   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6176 
  6177 * HOL/record: extensible records with schematic structural subtyping
  6178 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6179 still lacks various theorems and concrete record syntax;
  6180 
  6181 
  6182 *** HOLCF ***
  6183 
  6184 * removed "axioms" and "generated by" sections;
  6185 
  6186 * replaced "ops" section by extended "consts" section, which is capable of
  6187   handling the continuous function space "->" directly;
  6188 
  6189 * domain package:
  6190   . proves theorems immediately and stores them in the theory,
  6191   . creates hierachical name space,
  6192   . now uses normal mixfix annotations (instead of cinfix...),
  6193   . minor changes to some names and values (for consistency),
  6194   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6195   . separator between mutual domain defs: changed "," to "and",
  6196   . improved handling of sort constraints;  now they have to
  6197     appear on the left-hand side of the equations only;
  6198 
  6199 * fixed LAM <x,y,zs>.b syntax;
  6200 
  6201 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  6202 adm (%x. P (t x)), where P is chainfinite and t continuous;
  6203 
  6204 
  6205 *** FOL and ZF ***
  6206 
  6207 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6208   with `addloop' of the simplifier to faciliate case splitting in premises.
  6209 
  6210 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  6211 in HOL, they strip ALL and --> from proved theorems;
  6212 
  6213 
  6214 
  6215 New in Isabelle94-8 (May 1997)
  6216 ------------------------------
  6217 
  6218 *** General Changes ***
  6219 
  6220 * new utilities to build / run / maintain Isabelle etc. (in parts
  6221 still somewhat experimental); old Makefiles etc. still functional;
  6222 
  6223 * new 'Isabelle System Manual';
  6224 
  6225 * INSTALL text, together with ./configure and ./build scripts;
  6226 
  6227 * reimplemented type inference for greater efficiency, better error
  6228 messages and clean internal interface;
  6229 
  6230 * prlim command for dealing with lots of subgoals (an easier way of
  6231 setting goals_limit);
  6232 
  6233 
  6234 *** Syntax ***
  6235 
  6236 * supports alternative (named) syntax tables (parser and pretty
  6237 printer); internal interface is provided by add_modesyntax(_i);
  6238 
  6239 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  6240 be used in conjunction with the Isabelle symbol font; uses the
  6241 "symbols" syntax table;
  6242 
  6243 * added token_translation interface (may translate name tokens in
  6244 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  6245 the current print_mode); IMPORTANT: user print translation functions
  6246 are responsible for marking newly introduced bounds
  6247 (Syntax.mark_boundT);
  6248 
  6249 * token translations for modes "xterm" and "xterm_color" that display
  6250 names in bold, underline etc. or colors (which requires a color
  6251 version of xterm);
  6252