NEWS
author haftmann
Tue Oct 20 16:13:01 2009 +0200 (2009-10-20)
changeset 33037 b22e44496dc2
parent 33010 39f73a59e855
child 33057 764547b68538
permissions -rw-r--r--
replaced old_style infixes eq_set, subset, union, inter and variants by generic versions
     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 * Locale interpretation propagates mixins along the locale hierarchy.
    19 The currently only available mixins are the equations used to map
    20 local definitions to terms of the target domain of an interpretation.
    21 
    22 * Reactivated diagnositc command 'print_interps'.  Use 'print_interps l'
    23 to print all interpretations of locale l in the theory.  Interpretations
    24 in proofs are not shown.
    25 
    26 * Thoroughly revised locales tutorial.  New section on conditional
    27 interpretation.
    28 
    29 
    30 *** document preparation ***
    31 
    32 * New generalized style concept for printing terms:
    33 write @{foo (style) ...} instead of @{foo_style style ...}
    34 (old form is still retained for backward compatibility).
    35 Styles can be also applied for antiquotations prop, term_type and typeof.
    36 
    37 
    38 *** HOL ***
    39 
    40 * Most rules produced by inductive and datatype package
    41 have mandatory prefixes.
    42 INCOMPATIBILITY.
    43 
    44 * New proof method "smt" for a combination of first-order logic
    45 with equality, linear and nonlinear (natural/integer/real)
    46 arithmetic, and fixed-size bitvectors; there is also basic
    47 support for higher-order features (esp. lambda abstractions).
    48 It is an incomplete decision procedure based on external SMT
    49 solvers using the oracle mechanism; for the SMT solver Z3,
    50 this method is proof-producing. Certificates are provided to
    51 avoid calling the external solvers solely for re-checking proofs.
    52 
    53 * Reorganization of number theory:
    54   * former session NumberTheory now named Old_Number_Theory
    55   * new session Number_Theory by Jeremy Avigad; if possible, prefer this.
    56   * moved legacy theories Legacy_GCD and Primes from Library/ to Old_Number_Theory/;
    57   * moved theory Pocklington from Library/ to Old_Number_Theory/;
    58   * removed various references to Old_Number_Theory from HOL distribution.
    59 INCOMPATIBILITY.
    60 
    61 * Theory GCD now has functions Gcd/GCD and Lcm/LCM for the gcd and lcm
    62 of finite and infinite sets. It is shown that they form a complete
    63 lattice.
    64 
    65 * Split off prime number ingredients from theory GCD
    66 to theory Number_Theory/Primes;
    67 
    68 * Class semiring_div requires superclass no_zero_divisors and proof of
    69 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
    70 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
    71 generalized to class semiring_div, subsuming former theorems
    72 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
    73 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
    74 INCOMPATIBILITY.
    75 
    76 * New testing tool "Mirabelle" for automated (proof) tools. Applies
    77 several tools and tactics like sledgehammer, metis, or quickcheck, to
    78 every proof step in a theory. To be used in batch mode via the
    79 "mirabelle" utility.
    80 
    81 * New proof method "sos" (sum of squares) for nonlinear real
    82 arithmetic (originally due to John Harison). It requires
    83 Library/Sum_Of_Squares.  It is not a complete decision procedure but
    84 works well in practice on quantifier-free real arithmetic with +, -,
    85 *, ^, =, <= and <, i.e. boolean combinations of equalities and
    86 inequalities between polynomials. It makes use of external
    87 semidefinite programming solvers. Method "sos" generates a certificate
    88 that can be pasted into the proof thus avoiding the need to call an external
    89 tool every time the proof is checked.
    90 For more information and examples see src/HOL/Library/Sum_Of_Squares.
    91 
    92 * Code generator attributes follow the usual underscore convention:
    93     code_unfold     replaces    code unfold
    94     code_post       replaces    code post
    95     etc.
    96   INCOMPATIBILITY.
    97 
    98 * Refinements to lattice classes and sets:
    99   - less default intro/elim rules in locale variant, more default
   100     intro/elim rules in class variant: more uniformity
   101   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with le_inf_iff
   102   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and sup_aci)
   103   - renamed ACI to inf_sup_aci
   104   - new class "boolean_algebra"
   105   - class "complete_lattice" moved to separate theory "complete_lattice";
   106     corresponding constants (and abbreviations) renamed and with authentic syntax:
   107     Set.Inf ~>      Complete_Lattice.Inf
   108     Set.Sup ~>      Complete_Lattice.Sup
   109     Set.INFI ~>     Complete_Lattice.INFI
   110     Set.SUPR ~>     Complete_Lattice.SUPR
   111     Set.Inter ~>    Complete_Lattice.Inter
   112     Set.Union ~>    Complete_Lattice.Union
   113     Set.INTER ~>    Complete_Lattice.INTER
   114     Set.UNION ~>    Complete_Lattice.UNION
   115   - more convenient names for set intersection and union:
   116     Set.Int ~>      Set.inter
   117     Set.Un ~>       Set.union
   118   - authentic syntax for
   119     Set.Pow
   120     Set.image
   121   - mere abbreviations:
   122     Set.empty               (for bot)
   123     Set.UNIV                (for top)
   124     Set.inter               (for inf)
   125     Set.union               (for sup)
   126     Complete_Lattice.Inter  (for Inf)
   127     Complete_Lattice.Union  (for Sup)
   128     Complete_Lattice.INTER  (for INFI)
   129     Complete_Lattice.UNION  (for SUPR)
   130   - object-logic definitions as far as appropriate
   131 
   132 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   133 Un_subset_iff are explicitly deleted as default simp rules;  then
   134 also their lattice counterparts le_inf_iff and le_sup_iff have to be
   135 deleted to achieve the desired effect.
   136 
   137 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no
   138 simp rules by default any longer.  The same applies to
   139 min_max.inf_absorb1 etc.!  INCOMPATIBILITY.
   140 
   141 * sup_Int_eq and sup_Un_eq are no default pred_set_conv rules any longer.
   142 INCOMPATIBILITY.
   143 
   144 * Power operations on relations and functions are now one dedicate
   145 constant "compow" with infix syntax "^^".  Power operation on
   146 multiplicative monoids retains syntax "^" and is now defined generic
   147 in class power.  INCOMPATIBILITY.
   148 
   149 * Relation composition "R O S" now has a "more standard" argument
   150 order, i.e., "R O S = {(x,z). EX y. (x,y) : R & (y,z) : S }".
   151 INCOMPATIBILITY: Rewrite propositions with "S O R" --> "R O S". Proofs
   152 may occationally break, since the O_assoc rule was not rewritten like
   153 this.  Fix using O_assoc[symmetric].  The same applies to the curried
   154 version "R OO S".
   155 
   156 * Function "Inv" is renamed to "inv_onto" and function "inv" is now an
   157 abbreviation for "inv_onto UNIV". Lemmas are renamed accordingly.
   158 INCOMPATIBILITY.
   159 
   160 * ML antiquotation @{code_datatype} inserts definition of a datatype
   161 generated by the code generator; see Predicate.thy for an example.
   162 
   163 * New method "linarith" invokes existing linear arithmetic decision
   164 procedure only.
   165 
   166 * New implementation of quickcheck uses generic code generator;
   167 default generators are provided for all suitable HOL types, records
   168 and datatypes.
   169 
   170 * Renamed theorems:
   171 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   172 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   173 Suc_plus1 -> Suc_eq_plus1
   174 
   175 * Moved theorems:
   176 Wellfounded.in_inv_image -> Relation.in_inv_image
   177 
   178 * New sledgehammer option "Full Types" in Proof General settings menu.
   179 Causes full type information to be output to the ATPs.  This slows
   180 ATPs down considerably but eliminates a source of unsound "proofs"
   181 that fail later.
   182 
   183 * New method metisFT: A version of metis that uses full type information
   184 in order to avoid failures of proof reconstruction.
   185 
   186 * Discontinued ancient tradition to suffix certain ML module names
   187 with "_package", e.g.:
   188 
   189     DatatypePackage ~> Datatype
   190     InductivePackage ~> Inductive
   191 
   192 INCOMPATIBILITY.
   193 
   194 * Discontinued abbreviation "arbitrary" of constant
   195 "undefined". INCOMPATIBILITY, use "undefined" directly.
   196 
   197 * New evaluator "approximate" approximates an real valued term using
   198 the same method as the approximation method.
   199 
   200 * Method "approximate" supports now arithmetic expressions as
   201 boundaries of intervals and implements interval splitting and Taylor
   202 series expansion.
   203 
   204 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   205 the theorems in DERIV_intros assumes composition with an additional
   206 function and matches a variable to the derivative, which has to be
   207 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   208 the derivative of most elementary terms.
   209 
   210 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   211 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   212 
   213 
   214 *** ML ***
   215 
   216 * Removed some old-style infix operations using polymorphic equality.
   217 INCOMPATIBILITY.
   218 
   219 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   220 provides a high-level programming interface to synchronized state
   221 variables with atomic update.  This works via pure function
   222 application within a critical section -- its runtime should be as
   223 short as possible; beware of deadlocks if critical code is nested,
   224 either directly or indirectly via other synchronized variables!
   225 
   226 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   227 wraps raw ML references, explicitly indicating their non-thread-safe
   228 behaviour.  The Isar toplevel keeps this structure open, to
   229 accommodate Proof General as well as quick and dirty interactive
   230 experiments with references.
   231 
   232 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   233 parallel tactical reasoning.
   234 
   235 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   236 are similar to SUBPROOF, but are slightly more flexible: only the
   237 specified parts of the subgoal are imported into the context, and the
   238 body tactic may introduce new subgoals and schematic variables.
   239 
   240 * Old tactical METAHYPS, which does not observe the proof context, has
   241 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   242 or Subgoal.FOCUS etc.
   243 
   244 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   245 functors have their own ML name space there is no point to mark them
   246 separately.)  Minor INCOMPATIBILITY.
   247 
   248 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   249 
   250 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   251 cominators for "args".  INCOMPATIBILITY, need to use simplified
   252 Attrib/Method.setup introduced in Isabelle2009.
   253 
   254 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   255 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   256 last resort.  INCOMPATIBILITY.
   257 
   258 * Display.pretty_thm now requires a proper context (cf. former
   259 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   260 or even Display.pretty_thm_without_context as last resort.
   261 INCOMPATIBILITY.
   262 
   263 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   264 Syntax.pretty_typ/term directly, preferably with proper context
   265 instead of global theory.
   266 
   267 * Operations of structure Skip_Proof (formerly SkipProof) no longer
   268 require quick_and_dirty mode, which avoids critical setmp.
   269 
   270 
   271 *** System ***
   272 
   273 * Support for additional "Isabelle components" via etc/components, see
   274 also the system manual.
   275 
   276 * The isabelle makeall tool now operates on all components with
   277 IsaMakefile, not just hardwired "logics".
   278 
   279 * Discontinued support for Poly/ML 4.x versions.
   280 
   281 * Removed "compress" option from isabelle-process and isabelle usedir;
   282 this is always enabled.
   283 
   284 * More fine-grained control of proof parallelism, cf.
   285 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   286 
   287 
   288 
   289 New in Isabelle2009 (April 2009)
   290 --------------------------------
   291 
   292 *** General ***
   293 
   294 * Simplified main Isabelle executables, with less surprises on
   295 case-insensitive file-systems (such as Mac OS).
   296 
   297   - The main Isabelle tool wrapper is now called "isabelle" instead of
   298     "isatool."
   299 
   300   - The former "isabelle" alias for "isabelle-process" has been
   301     removed (should rarely occur to regular users).
   302 
   303   - The former "isabelle-interface" and its alias "Isabelle" have been
   304     removed (interfaces are now regular Isabelle tools).
   305 
   306 Within scripts and make files, the Isabelle environment variables
   307 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   308 respectively.  (The latter are still available as legacy feature.)
   309 
   310 The old isabelle-interface wrapper could react in confusing ways if
   311 the interface was uninstalled or changed otherwise.  Individual
   312 interface tool configuration is now more explicit, see also the
   313 Isabelle system manual.  In particular, Proof General is now available
   314 via "isabelle emacs".
   315 
   316 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   317 purge installed copies of Isabelle executables and re-run "isabelle
   318 install -p ...", or use symlinks.
   319 
   320 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   321 old ~/isabelle, which was slightly non-standard and apt to cause
   322 surprises on case-insensitive file-systems (such as Mac OS).
   323 
   324 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   325 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   326 care is required when using older releases of Isabelle.  Note that
   327 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   328 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   329 
   330 * Proofs of fully specified statements are run in parallel on
   331 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   332 a regular 4-core machine, if the initial heap space is made reasonably
   333 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   334 
   335 * The main reference manuals ("isar-ref", "implementation", and
   336 "system") have been updated and extended.  Formally checked references
   337 as hyperlinks are now available uniformly.
   338 
   339 
   340 *** Pure ***
   341 
   342 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   343 respects.  The most important changes are listed below.  See the
   344 Tutorial on Locales ("locales" manual) for details.
   345 
   346 - In locale expressions, instantiation replaces renaming.  Parameters
   347 must be declared in a for clause.  To aid compatibility with previous
   348 parameter inheritance, in locale declarations, parameters that are not
   349 'touched' (instantiation position "_" or omitted) are implicitly added
   350 with their syntax at the beginning of the for clause.
   351 
   352 - Syntax from abbreviations and definitions in locales is available in
   353 locale expressions and context elements.  The latter is particularly
   354 useful in locale declarations.
   355 
   356 - More flexible mechanisms to qualify names generated by locale
   357 expressions.  Qualifiers (prefixes) may be specified in locale
   358 expressions, and can be marked as mandatory (syntax: "name!:") or
   359 optional (syntax "name?:").  The default depends for plain "name:"
   360 depends on the situation where a locale expression is used: in
   361 commands 'locale' and 'sublocale' prefixes are optional, in
   362 'interpretation' and 'interpret' prefixes are mandatory.  The old
   363 implicit qualifiers derived from the parameter names of a locale are
   364 no longer generated.
   365 
   366 - Command "sublocale l < e" replaces "interpretation l < e".  The
   367 instantiation clause in "interpretation" and "interpret" (square
   368 brackets) is no longer available.  Use locale expressions.
   369 
   370 - When converting proof scripts, mandatory qualifiers in
   371 'interpretation' and 'interpret' should be retained by default, even
   372 if this is an INCOMPATIBILITY compared to former behavior.  In the
   373 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   374 in locale expressions range over a single locale instance only.
   375 
   376 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   377 In existing theorem specifications replace the includes element by the
   378 respective context elements of the included locale, omitting those
   379 that are already present in the theorem specification.  Multiple
   380 assume elements of a locale should be replaced by a single one
   381 involving the locale predicate.  In the proof body, declarations (most
   382 notably theorems) may be regained by interpreting the respective
   383 locales in the proof context as required (command "interpret").
   384 
   385 If using "includes" in replacement of a target solely because the
   386 parameter types in the theorem are not as general as in the target,
   387 consider declaring a new locale with additional type constraints on
   388 the parameters (context element "constrains").
   389 
   390 - Discontinued "locale (open)".  INCOMPATIBILITY.
   391 
   392 - Locale interpretation commands no longer attempt to simplify goal.
   393 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   394 methods intro_locales and unfold_locales to clarify.
   395 
   396 - Locale interpretation commands no longer accept interpretation
   397 attributes.  INCOMPATIBILITY.
   398 
   399 * Class declaration: so-called "base sort" must not be given in import
   400 list any longer, but is inferred from the specification.  Particularly
   401 in HOL, write
   402 
   403     class foo = ...
   404 
   405 instead of
   406 
   407     class foo = type + ...
   408 
   409 * Class target: global versions of theorems stemming do not carry a
   410 parameter prefix any longer.  INCOMPATIBILITY.
   411 
   412 * Class 'instance' command no longer accepts attached definitions.
   413 INCOMPATIBILITY, use proper 'instantiation' target instead.
   414 
   415 * Recovered hiding of consts, which was accidentally broken in
   416 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   417 makes c inaccessible; consider using ``hide (open) const c'' instead.
   418 
   419 * Slightly more coherent Pure syntax, with updated documentation in
   420 isar-ref manual.  Removed locales meta_term_syntax and
   421 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   422 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   423 directly in regular applications.
   424 
   425 * There is a new syntactic category "float_const" for signed decimal
   426 fractions (e.g. 123.45 or -123.45).
   427 
   428 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   429 interface with 'setup' command instead.
   430 
   431 * Command 'local_setup' is similar to 'setup', but operates on a local
   432 theory context.
   433 
   434 * The 'axiomatization' command now only works within a global theory
   435 context.  INCOMPATIBILITY.
   436 
   437 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   438 hypotheses.  Sorts required in the course of reasoning need to be
   439 covered by the constraints in the initial statement, completed by the
   440 type instance information of the background theory.  Non-trivial sort
   441 hypotheses, which rarely occur in practice, may be specified via
   442 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   443 
   444   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   445 
   446 The result contains an implicit sort hypotheses as before --
   447 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   448 normalization.
   449 
   450 * Generalized Isar history, with support for linear undo, direct state
   451 addressing etc.
   452 
   453 * Changed defaults for unify configuration options:
   454 
   455   unify_trace_bound = 50 (formerly 25)
   456   unify_search_bound = 60 (formerly 30)
   457 
   458 * Different bookkeeping for code equations (INCOMPATIBILITY):
   459 
   460   a) On theory merge, the last set of code equations for a particular
   461      constant is taken (in accordance with the policy applied by other
   462      parts of the code generator framework).
   463 
   464   b) Code equations stemming from explicit declarations (e.g. code
   465      attribute) gain priority over default code equations stemming
   466      from definition, primrec, fun etc.
   467 
   468 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   469 
   470 * Unified theorem tables for both code generators.  Thus [code
   471 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   472 
   473 * Command 'find_consts' searches for constants based on type and name
   474 patterns, e.g.
   475 
   476     find_consts "_ => bool"
   477 
   478 By default, matching is against subtypes, but it may be restricted to
   479 the whole type.  Searching by name is possible.  Multiple queries are
   480 conjunctive and queries may be negated by prefixing them with a
   481 hyphen:
   482 
   483     find_consts strict: "_ => bool" name: "Int" -"int => int"
   484 
   485 * New 'find_theorems' criterion "solves" matches theorems that
   486 directly solve the current goal (modulo higher-order unification).
   487 
   488 * Auto solve feature for main theorem statements: whenever a new goal
   489 is stated, "find_theorems solves" is called; any theorems that could
   490 solve the lemma directly are listed as part of the goal state.
   491 Cf. associated options in Proof General Isabelle settings menu,
   492 enabled by default, with reasonable timeout for pathological cases of
   493 higher-order unification.
   494 
   495 
   496 *** Document preparation ***
   497 
   498 * Antiquotation @{lemma} now imitates a regular terminal proof,
   499 demanding keyword 'by' and supporting the full method expression
   500 syntax just like the Isar command 'by'.
   501 
   502 
   503 *** HOL ***
   504 
   505 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   506 points Main and Complex_Main remain as before.
   507 
   508 * Logic image HOL-Plain provides a minimal HOL with the most important
   509 tools available (inductive, datatype, primrec, ...).  This facilitates
   510 experimentation and tool development.  Note that user applications
   511 (and library theories) should never refer to anything below theory
   512 Main, as before.
   513 
   514 * Logic image HOL-Main stops at theory Main, and thus facilitates
   515 experimentation due to shorter build times.
   516 
   517 * Logic image HOL-NSA contains theories of nonstandard analysis which
   518 were previously part of former HOL-Complex.  Entry point Hyperreal
   519 remains valid, but theories formerly using Complex_Main should now use
   520 new entry point Hypercomplex.
   521 
   522 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   523 Posix processes.  Avoids potentially expensive forking of the ML
   524 process.  New thread-based implementation also works on non-Unix
   525 platforms (Cygwin).  Provers are no longer hardwired, but defined
   526 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   527 commands are covered in the isar-ref manual.
   528 
   529 * Wrapper scripts for remote SystemOnTPTP service allows to use
   530 sledgehammer without local ATP installation (Vampire etc.). Other
   531 provers may be included via suitable ML wrappers, see also
   532 src/HOL/ATP_Linkup.thy.
   533 
   534 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   535 menu.
   536 
   537 * The metis method no longer fails because the theorem is too trivial
   538 (contains the empty clause).
   539 
   540 * The metis method now fails in the usual manner, rather than raising
   541 an exception, if it determines that it cannot prove the theorem.
   542 
   543 * Method "coherent" implements a prover for coherent logic (see also
   544 src/Tools/coherent.ML).
   545 
   546 * Constants "undefined" and "default" replace "arbitrary".  Usually
   547 "undefined" is the right choice to replace "arbitrary", though
   548 logically there is no difference.  INCOMPATIBILITY.
   549 
   550 * Command "value" now integrates different evaluation mechanisms.  The
   551 result of the first successful evaluation mechanism is printed.  In
   552 square brackets a particular named evaluation mechanisms may be
   553 specified (currently, [SML], [code] or [nbe]).  See further
   554 src/HOL/ex/Eval_Examples.thy.
   555 
   556 * Normalization by evaluation now allows non-leftlinear equations.
   557 Declare with attribute [code nbe].
   558 
   559 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   560 as the structured Isar versions "cases" and "induct", cf. the
   561 corresponding "cases" and "induct" attributes.  Mutual induction rules
   562 are now presented as a list of individual projections
   563 (e.g. foo_bar.inducts for types foo and bar); the old format with
   564 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   565 rare situations a different rule is selected --- notably nested tuple
   566 elimination instead of former prod.exhaust: use explicit (case_tac t
   567 rule: prod.exhaust) here.
   568 
   569 * Attributes "cases", "induct", "coinduct" support "del" option.
   570 
   571 * Removed fact "case_split_thm", which duplicates "case_split".
   572 
   573 * The option datatype has been moved to a new theory Option.  Renamed
   574 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   575 
   576 * New predicate "strict_mono" classifies strict functions on partial
   577 orders.  With strict functions on linear orders, reasoning about
   578 (in)equalities is facilitated by theorems "strict_mono_eq",
   579 "strict_mono_less_eq" and "strict_mono_less".
   580 
   581 * Some set operations are now proper qualified constants with
   582 authentic syntax.  INCOMPATIBILITY:
   583 
   584     op Int ~>   Set.Int
   585     op Un ~>    Set.Un
   586     INTER ~>    Set.INTER
   587     UNION ~>    Set.UNION
   588     Inter ~>    Set.Inter
   589     Union ~>    Set.Union
   590     {} ~>       Set.empty
   591     UNIV ~>     Set.UNIV
   592 
   593 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   594 theory Set.
   595 
   596 * Auxiliary class "itself" has disappeared -- classes without any
   597 parameter are treated as expected by the 'class' command.
   598 
   599 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   600 
   601 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   602 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   603 
   604 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   605 method "approximation".  It proves formulas on real values by using
   606 interval arithmetic.  In the formulas are also the transcendental
   607 functions sin, cos, tan, atan, ln, exp and the constant pi are
   608 allowed. For examples see
   609 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   610 
   611 * Theory "Reflection" now resides in HOL/Library.
   612 
   613 * Entry point to Word library now simply named "Word".
   614 INCOMPATIBILITY.
   615 
   616 * Made source layout more coherent with logical distribution
   617 structure:
   618 
   619     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   620     src/HOL/Library/Code_Message.thy ~> src/HOL/
   621     src/HOL/Library/GCD.thy ~> src/HOL/
   622     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   623     src/HOL/Library/Parity.thy ~> src/HOL/
   624     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   625     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   626     src/HOL/Real/Lubs.thy ~> src/HOL/
   627     src/HOL/Real/PReal.thy ~> src/HOL/
   628     src/HOL/Real/Rational.thy ~> src/HOL/
   629     src/HOL/Real/RComplete.thy ~> src/HOL/
   630     src/HOL/Real/RealDef.thy ~> src/HOL/
   631     src/HOL/Real/RealPow.thy ~> src/HOL/
   632     src/HOL/Real/Real.thy ~> src/HOL/
   633     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   634     src/HOL/Complex/Complex.thy ~> src/HOL/
   635     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   636     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   637     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   638     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   639     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   640     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   641     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   642     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   643     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   644     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   645     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   646     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   647     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   648     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   649     src/HOL/Real/Float ~> src/HOL/Library/
   650     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   651     src/HOL/Real/RealVector.thy ~> src/HOL/
   652 
   653     src/HOL/arith_data.ML ~> src/HOL/Tools
   654     src/HOL/hologic.ML ~> src/HOL/Tools
   655     src/HOL/simpdata.ML ~> src/HOL/Tools
   656     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   657     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   658     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   659     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   660     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   661     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   662     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   663 
   664     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   665     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   666     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   667     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   668     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   669     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   670 
   671 * If methods "eval" and "evaluation" encounter a structured proof
   672 state with !!/==>, only the conclusion is evaluated to True (if
   673 possible), avoiding strange error messages.
   674 
   675 * Method "sizechange" automates termination proofs using (a
   676 modification of) the size-change principle.  Requires SAT solver.  See
   677 src/HOL/ex/Termination.thy for examples.
   678 
   679 * Simplifier: simproc for let expressions now unfolds if bound
   680 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   681 
   682 * Method "arith": Linear arithmetic now ignores all inequalities when
   683 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   684 
   685 * New attribute "arith" for facts that should always be used
   686 automatically by arithmetic. It is intended to be used locally in
   687 proofs, e.g.
   688 
   689   assumes [arith]: "x > 0"
   690 
   691 Global usage is discouraged because of possible performance impact.
   692 
   693 * New classes "top" and "bot" with corresponding operations "top" and
   694 "bot" in theory Orderings; instantiation of class "complete_lattice"
   695 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   696 
   697 * Changed definition lemma "less_fun_def" in order to provide an
   698 instance for preorders on functions; use lemma "less_le" instead.
   699 INCOMPATIBILITY.
   700 
   701 * Theory Orderings: class "wellorder" moved here, with explicit
   702 induction rule "less_induct" as assumption.  For instantiation of
   703 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   704 INCOMPATIBILITY.
   705 
   706 * Theory Orderings: added class "preorder" as superclass of "order".
   707 INCOMPATIBILITY: Instantiation proofs for order, linorder
   708 etc. slightly changed.  Some theorems named order_class.* now named
   709 preorder_class.*.
   710 
   711 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   712 "diag" to "Id_on".
   713 
   714 * Theory Finite_Set: added a new fold combinator of type
   715 
   716   ('a => 'b => 'b) => 'b => 'a set => 'b
   717 
   718 Occasionally this is more convenient than the old fold combinator
   719 which is now defined in terms of the new one and renamed to
   720 fold_image.
   721 
   722 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   723 and "ring_simps" have been replaced by "algebra_simps" (which can be
   724 extended with further lemmas!).  At the moment both still exist but
   725 the former will disappear at some point.
   726 
   727 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   728 class recpower.  Type-specific simp rules for various recpower types
   729 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   730 
   731 rat_power_0    -> power_0
   732 rat_power_Suc  -> power_Suc
   733 realpow_0      -> power_0
   734 realpow_Suc    -> power_Suc
   735 complexpow_0   -> power_0
   736 complexpow_Suc -> power_Suc
   737 power_poly_0   -> power_0
   738 power_poly_Suc -> power_Suc
   739 
   740 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   741 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   742 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   743 of lemmas from Divides has been generalized from nat to class
   744 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   745 renames resulting from duplicate elimination:
   746 
   747     dvd_def_mod ~>          dvd_eq_mod_eq_0
   748     zero_dvd_iff ~>         dvd_0_left_iff
   749     dvd_0 ~>                dvd_0_right
   750     DIVISION_BY_ZERO_DIV ~> div_by_0
   751     DIVISION_BY_ZERO_MOD ~> mod_by_0
   752     mult_div ~>             div_mult_self2_is_id
   753     mult_mod ~>             mod_mult_self2_is_0
   754 
   755 * Theory IntDiv: removed many lemmas that are instances of class-based
   756 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   757 rename old lemmas as follows:
   758 
   759 dvd_diff               -> nat_dvd_diff
   760 dvd_zminus_iff         -> dvd_minus_iff
   761 mod_add1_eq            -> mod_add_eq
   762 mod_mult1_eq           -> mod_mult_right_eq
   763 mod_mult1_eq'          -> mod_mult_left_eq
   764 mod_mult_distrib_mod   -> mod_mult_eq
   765 nat_mod_add_left_eq    -> mod_add_left_eq
   766 nat_mod_add_right_eq   -> mod_add_right_eq
   767 nat_mod_div_trivial    -> mod_div_trivial
   768 nat_mod_mod_trivial    -> mod_mod_trivial
   769 zdiv_zadd_self1        -> div_add_self1
   770 zdiv_zadd_self2        -> div_add_self2
   771 zdiv_zmult_self1       -> div_mult_self2_is_id
   772 zdiv_zmult_self2       -> div_mult_self1_is_id
   773 zdvd_triv_left         -> dvd_triv_left
   774 zdvd_triv_right        -> dvd_triv_right
   775 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   776 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   777 zmod_zadd_left_eq      -> mod_add_left_eq
   778 zmod_zadd_right_eq     -> mod_add_right_eq
   779 zmod_zadd_self1        -> mod_add_self1
   780 zmod_zadd_self2        -> mod_add_self2
   781 zmod_zadd1_eq          -> mod_add_eq
   782 zmod_zdiff1_eq         -> mod_diff_eq
   783 zmod_zdvd_zmod         -> mod_mod_cancel
   784 zmod_zmod_cancel       -> mod_mod_cancel
   785 zmod_zmult_self1       -> mod_mult_self2_is_0
   786 zmod_zmult_self2       -> mod_mult_self1_is_0
   787 zmod_1                 -> mod_by_1
   788 zdiv_1                 -> div_by_1
   789 zdvd_abs1              -> abs_dvd_iff
   790 zdvd_abs2              -> dvd_abs_iff
   791 zdvd_refl              -> dvd_refl
   792 zdvd_trans             -> dvd_trans
   793 zdvd_zadd              -> dvd_add
   794 zdvd_zdiff             -> dvd_diff
   795 zdvd_zminus_iff        -> dvd_minus_iff
   796 zdvd_zminus2_iff       -> minus_dvd_iff
   797 zdvd_zmultD            -> dvd_mult_right
   798 zdvd_zmultD2           -> dvd_mult_left
   799 zdvd_zmult_mono        -> mult_dvd_mono
   800 zdvd_0_right           -> dvd_0_right
   801 zdvd_0_left            -> dvd_0_left_iff
   802 zdvd_1_left            -> one_dvd
   803 zminus_dvd_iff         -> minus_dvd_iff
   804 
   805 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   806 
   807 * The real numbers offer decimal input syntax: 12.34 is translated
   808 into 1234/10^2. This translation is not reversed upon output.
   809 
   810 * Theory Library/Polynomial defines an abstract type 'a poly of
   811 univariate polynomials with coefficients of type 'a.  In addition to
   812 the standard ring operations, it also supports div and mod.  Code
   813 generation is also supported, using list-style constructors.
   814 
   815 * Theory Library/Inner_Product defines a class of real_inner for real
   816 inner product spaces, with an overloaded operation inner :: 'a => 'a
   817 => real.  Class real_inner is a subclass of real_normed_vector from
   818 theory RealVector.
   819 
   820 * Theory Library/Product_Vector provides instances for the product
   821 type 'a * 'b of several classes from RealVector and Inner_Product.
   822 Definitions of addition, subtraction, scalar multiplication, norms,
   823 and inner products are included.
   824 
   825 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   826 addition to the field operations, numerals and case syntax are also
   827 supported.
   828 
   829 * Theory Library/Diagonalize provides constructive version of Cantor's
   830 first diagonalization argument.
   831 
   832 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   833 zlcm (for int); carried together from various gcd/lcm developements in
   834 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   835 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   836 may recover tupled syntax as follows:
   837 
   838     hide (open) const gcd
   839     abbreviation gcd where
   840       "gcd == (%(a, b). GCD.gcd a b)"
   841     notation (output)
   842       GCD.gcd ("gcd '(_, _')")
   843 
   844 The same works for lcm, zgcd, zlcm.
   845 
   846 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   847 instantiations for algebraic structures.  Removed some duplicate
   848 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   849 
   850 * ML antiquotation @{code} takes a constant as argument and generates
   851 corresponding code in background and inserts name of the corresponding
   852 resulting ML value/function/datatype constructor binding in place.
   853 All occurrences of @{code} with a single ML block are generated
   854 simultaneously.  Provides a generic and safe interface for
   855 instrumentalizing code generation.  See
   856 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   857 In future you ought to refrain from ad-hoc compiling generated SML
   858 code on the ML toplevel.  Note that (for technical reasons) @{code}
   859 cannot refer to constants for which user-defined serializations are
   860 set.  Refer to the corresponding ML counterpart directly in that
   861 cases.
   862 
   863 * Command 'rep_datatype': instead of theorem names the command now
   864 takes a list of terms denoting the constructors of the type to be
   865 represented as datatype.  The characteristic theorems have to be
   866 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   867 have disappeared in favour of existing ones:
   868 
   869     unit_induct                 ~> unit.induct
   870     prod_induct                 ~> prod.induct
   871     sum_induct                  ~> sum.induct
   872     Suc_Suc_eq                  ~> nat.inject
   873     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   874 
   875 
   876 *** HOL-Algebra ***
   877 
   878 * New locales for orders and lattices where the equivalence relation
   879 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   880 locales use a record structure with field eq for the equivalence.
   881 
   882 * New theory of factorial domains.
   883 
   884 * Units_l_inv and Units_r_inv are now simp rules by default.
   885 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   886 and/or r_inv will now also require deletion of these lemmas.
   887 
   888 * Renamed the following theorems, INCOMPATIBILITY:
   889 
   890 UpperD ~> Upper_memD
   891 LowerD ~> Lower_memD
   892 least_carrier ~> least_closed
   893 greatest_carrier ~> greatest_closed
   894 greatest_Lower_above ~> greatest_Lower_below
   895 one_zero ~> carrier_one_zero
   896 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   897 
   898 
   899 *** HOL-Nominal ***
   900 
   901 * Nominal datatypes can now contain type-variables.
   902 
   903 * Commands 'nominal_inductive' and 'equivariance' work with local
   904 theory targets.
   905 
   906 * Nominal primrec can now works with local theory targets and its
   907 specification syntax now conforms to the general format as seen in
   908 'inductive' etc.
   909 
   910 * Method "perm_simp" honours the standard simplifier attributes
   911 (no_asm), (no_asm_use) etc.
   912 
   913 * The new predicate #* is defined like freshness, except that on the
   914 left hand side can be a set or list of atoms.
   915 
   916 * Experimental command 'nominal_inductive2' derives strong induction
   917 principles for inductive definitions.  In contrast to
   918 'nominal_inductive', which can only deal with a fixed number of
   919 binders, it can deal with arbitrary expressions standing for sets of
   920 atoms to be avoided.  The only inductive definition we have at the
   921 moment that needs this generalisation is the typing rule for Lets in
   922 the algorithm W:
   923 
   924  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   925  -----------------------------------------------------------------
   926          Gamma |- Let x be t1 in t2 : T2
   927 
   928 In this rule one wants to avoid all the binders that are introduced by
   929 "close Gamma T1".  We are looking for other examples where this
   930 feature might be useful.  Please let us know.
   931 
   932 
   933 *** HOLCF ***
   934 
   935 * Reimplemented the simplification procedure for proving continuity
   936 subgoals.  The new simproc is extensible; users can declare additional
   937 continuity introduction rules with the attribute [cont2cont].
   938 
   939 * The continuity simproc now uses a different introduction rule for
   940 solving continuity subgoals on terms with lambda abstractions.  In
   941 some rare cases the new simproc may fail to solve subgoals that the
   942 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   943 Potential INCOMPATIBILITY.
   944 
   945 * Command 'fixrec': specification syntax now conforms to the general
   946 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   947 examples.  INCOMPATIBILITY.
   948 
   949 
   950 *** ZF ***
   951 
   952 * Proof of Zorn's Lemma for partial orders.
   953 
   954 
   955 *** ML ***
   956 
   957 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   958 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   959 depends on multithreading, so timouts will not work before Poly/ML
   960 5.2.1!
   961 
   962 * High-level support for concurrent ML programming, see
   963 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   964 particularly convenient to organize independent functional
   965 computations.  The concept of "synchronized variables" provides a
   966 higher-order interface for components with shared state, avoiding the
   967 delicate details of mutexes and condition variables.  (Requires
   968 Poly/ML 5.2.1 or later.)
   969 
   970 * ML bindings produced via Isar commands are stored within the Isar
   971 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   972 become thread-safe and work with undo as expected (concerning
   973 top-level bindings, not side-effects on global references).
   974 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   975 compiler at runtime; really global bindings need to be given outside a
   976 theory.  (Requires Poly/ML 5.2 or later.)
   977 
   978 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   979 context.  Top-level ML bindings are stored within the proof context in
   980 a purely sequential fashion, disregarding the nested proof structure.
   981 ML bindings introduced by 'ML_prf' are discarded at the end of the
   982 proof.  (Requires Poly/ML 5.2 or later.)
   983 
   984 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   985 and Method.setup, as well as Isar commands 'attribute_setup' and
   986 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   987 existing code accordingly, or use plain 'setup' together with old
   988 Method.add_method.
   989 
   990 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   991 to 'a -> thm, while results are always tagged with an authentic oracle
   992 name.  The Isar command 'oracle' is now polymorphic, no argument type
   993 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   994 accordingly.  Note that extra performance may be gained by producing
   995 the cterm carefully, avoiding slow Thm.cterm_of.
   996 
   997 * Simplified interface for defining document antiquotations via
   998 ThyOutput.antiquotation, ThyOutput.output, and optionally
   999 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1000 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1001 examples.
  1002 
  1003 * More systematic treatment of long names, abstract name bindings, and
  1004 name space operations.  Basic operations on qualified names have been
  1005 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1006 Long_Name.append.  Old type bstring has been mostly replaced by
  1007 abstract type binding (see structure Binding), which supports precise
  1008 qualification by packages and local theory targets, as well as proper
  1009 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1010 bstring values into Binding.name, or better pass through abstract
  1011 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1012 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1013 
  1014 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1015 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1016 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1017 
  1018 * Disposed old type and term read functions (Sign.read_def_typ,
  1019 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1020 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1021 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1022 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1023 resort for legacy applications.
  1024 
  1025 * Disposed old declarations, tactics, tactic combinators that refer to
  1026 the simpset or claset of an implicit theory (such as Addsimps,
  1027 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1028 embedded ML text, or local_simpset_of with a proper context passed as
  1029 explicit runtime argument.
  1030 
  1031 * Rules and tactics that read instantiations (read_instantiate,
  1032 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1033 context, which is required for parsing and type-checking.  Moreover,
  1034 the variables are specified as plain indexnames, not string encodings
  1035 thereof.  INCOMPATIBILITY.
  1036 
  1037 * Generic Toplevel.add_hook interface allows to analyze the result of
  1038 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1039 for theorem dependency output of transactions resulting in a new
  1040 theory state.
  1041 
  1042 * ML antiquotations: block-structured compilation context indicated by
  1043 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1044 
  1045   @{binding name}                         - basic name binding
  1046   @{let ?pat = term}                      - term abbreviation (HO matching)
  1047   @{note name = fact}                     - fact abbreviation
  1048   @{thm fact}                             - singleton fact (with attributes)
  1049   @{thms fact}                            - general fact (with attributes)
  1050   @{lemma prop by method}                 - singleton goal
  1051   @{lemma prop by meth1 meth2}            - singleton goal
  1052   @{lemma prop1 ... propN by method}      - general goal
  1053   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1054   @{lemma (open) ...}                     - open derivation
  1055 
  1056 
  1057 *** System ***
  1058 
  1059 * The Isabelle "emacs" tool provides a specific interface to invoke
  1060 Proof General / Emacs, with more explicit failure if that is not
  1061 installed (the old isabelle-interface script silently falls back on
  1062 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1063 installation location of the Proof General distribution.
  1064 
  1065 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1066 the Isabelle process into a JVM/Scala application.  See
  1067 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1068 process wrapper has been discontinued.)
  1069 
  1070 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1071 
  1072 * Various status messages (with exact source position information) are
  1073 emitted, if proper markup print mode is enabled.  This allows
  1074 user-interface components to provide detailed feedback on internal
  1075 prover operations.
  1076 
  1077 
  1078 
  1079 New in Isabelle2008 (June 2008)
  1080 -------------------------------
  1081 
  1082 *** General ***
  1083 
  1084 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1085 and updated, with formally checked references as hyperlinks.
  1086 
  1087 * Theory loader: use_thy (and similar operations) no longer set the
  1088 implicit ML context, which was occasionally hard to predict and in
  1089 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1090 provides a proper context already.
  1091 
  1092 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1093 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1094 'use' within a theory file will do the job.
  1095 
  1096 * Name space merge now observes canonical order, i.e. the second space
  1097 is inserted into the first one, while existing entries in the first
  1098 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1099 swap theory imports.
  1100 
  1101 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1102 INCOMPATIBILITY in identifier syntax etc.
  1103 
  1104 * Outer syntax: string tokens no longer admit escaped white space,
  1105 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1106 white space without escapes.
  1107 
  1108 * Outer syntax: string tokens may contain arbitrary character codes
  1109 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1110 "foo_bar".
  1111 
  1112 
  1113 *** Pure ***
  1114 
  1115 * Context-dependent token translations.  Default setup reverts locally
  1116 fixed variables, and adds hilite markup for undeclared frees.
  1117 
  1118 * Unused theorems can be found using the new command 'unused_thms'.
  1119 There are three ways of invoking it:
  1120 
  1121 (1) unused_thms
  1122      Only finds unused theorems in the current theory.
  1123 
  1124 (2) unused_thms thy_1 ... thy_n -
  1125      Finds unused theorems in the current theory and all of its ancestors,
  1126      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1127 
  1128 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1129      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1130      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1131      their ancestors.
  1132 
  1133 In order to increase the readability of the list produced by
  1134 unused_thms, theorems that have been created by a particular instance
  1135 of a theory command such as 'inductive' or 'function' are considered
  1136 to belong to the same "group", meaning that if at least one theorem in
  1137 this group is used, the other theorems in the same group are no longer
  1138 reported as unused.  Moreover, if all theorems in the group are
  1139 unused, only one theorem in the group is displayed.
  1140 
  1141 Note that proof objects have to be switched on in order for
  1142 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1143 usually the case when using Proof General with the default settings).
  1144 
  1145 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1146 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1147 duplicate fact bindings, or even accidental fact duplications.  Note
  1148 that tools may maintain dynamically scoped facts systematically, using
  1149 PureThy.add_thms_dynamic.
  1150 
  1151 * Command 'hide' now allows to hide from "fact" name space as well.
  1152 
  1153 * Eliminated destructive theorem database, simpset, claset, and
  1154 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1155 update of theories within ML code.
  1156 
  1157 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1158 INCOMPATIBILITY, object-logics depending on former Pure require
  1159 additional setup PureThy.old_appl_syntax_setup; object-logics
  1160 depending on former CPure need to refer to Pure.
  1161 
  1162 * Commands 'use' and 'ML' are now purely functional, operating on
  1163 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1164 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1165 INCOMPATIBILITY.
  1166 
  1167 * Command 'setup': discontinued implicit version with ML reference.
  1168 
  1169 * Instantiation target allows for simultaneous specification of class
  1170 instance operations together with an instantiation proof.
  1171 Type-checking phase allows to refer to class operations uniformly.
  1172 See src/HOL/Complex/Complex.thy for an Isar example and
  1173 src/HOL/Library/Eval.thy for an ML example.
  1174 
  1175 * Indexing of literal facts: be more serious about including only
  1176 facts from the visible specification/proof context, but not the
  1177 background context (locale etc.).  Affects `prop` notation and method
  1178 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1179 situations.
  1180 
  1181 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1182 "(open)" option, which used to expose internal bound variables to the
  1183 proof text.
  1184 
  1185 * Isar statements: removed obsolete case "rule_context".
  1186 INCOMPATIBILITY, better use explicit fixes/assumes.
  1187 
  1188 * Locale proofs: default proof step now includes 'unfold_locales';
  1189 hence 'proof' without argument may be used to unfold locale
  1190 predicates.
  1191 
  1192 
  1193 *** Document preparation ***
  1194 
  1195 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1196 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1197 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1198 spot); renamed link color from "darkblue" to "linkcolor" (default
  1199 value unchanged, can be redefined via \definecolor); no longer sets
  1200 "a4paper" option (unnecessary or even intrusive).
  1201 
  1202 * Antiquotation @{lemma A method} proves proposition A by the given
  1203 method (either a method name or a method name plus (optional) method
  1204 arguments in parentheses) and prints A just like @{prop A}.
  1205 
  1206 
  1207 *** HOL ***
  1208 
  1209 * New primrec package.  Specification syntax conforms in style to
  1210 definition/function/....  No separate induction rule is provided.  The
  1211 "primrec" command distinguishes old-style and new-style specifications
  1212 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1213 When adjusting theories, beware: constants stemming from new-style
  1214 primrec specifications have authentic syntax.
  1215 
  1216 * Metis prover is now an order of magnitude faster, and also works
  1217 with multithreading.
  1218 
  1219 * Metis: the maximum number of clauses that can be produced from a
  1220 theorem is now given by the attribute max_clauses.  Theorems that
  1221 exceed this number are ignored, with a warning printed.
  1222 
  1223 * Sledgehammer no longer produces structured proofs by default. To
  1224 enable, declare [[sledgehammer_full = true]].  Attributes
  1225 reconstruction_modulus, reconstruction_sorts renamed
  1226 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1227 
  1228 * Method "induct_scheme" derives user-specified induction rules
  1229 from well-founded induction and completeness of patterns. This factors
  1230 out some operations that are done internally by the function package
  1231 and makes them available separately.  See
  1232 src/HOL/ex/Induction_Scheme.thy for examples.
  1233 
  1234 * More flexible generation of measure functions for termination
  1235 proofs: Measure functions can be declared by proving a rule of the
  1236 form "is_measure f" and giving it the [measure_function] attribute.
  1237 The "is_measure" predicate is logically meaningless (always true), and
  1238 just guides the heuristic.  To find suitable measure functions, the
  1239 termination prover sets up the goal "is_measure ?f" of the appropriate
  1240 type and generates all solutions by prolog-style backwards proof using
  1241 the declared rules.
  1242 
  1243 This setup also deals with rules like 
  1244 
  1245   "is_measure f ==> is_measure (list_size f)"
  1246 
  1247 which accommodates nested datatypes that recurse through lists.
  1248 Similar rules are predeclared for products and option types.
  1249 
  1250 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1251 
  1252   INCOMPATIBILITIES:
  1253 
  1254   - Definitions of overloaded constants on sets have to be replaced by
  1255     definitions on => and bool.
  1256 
  1257   - Some definitions of overloaded operators on sets can now be proved
  1258     using the definitions of the operators on => and bool.  Therefore,
  1259     the following theorems have been renamed:
  1260 
  1261       subset_def   -> subset_eq
  1262       psubset_def  -> psubset_eq
  1263       set_diff_def -> set_diff_eq
  1264       Compl_def    -> Compl_eq
  1265       Sup_set_def  -> Sup_set_eq
  1266       Inf_set_def  -> Inf_set_eq
  1267       sup_set_def  -> sup_set_eq
  1268       inf_set_def  -> inf_set_eq
  1269 
  1270   - Due to the incompleteness of the HO unification algorithm, some
  1271     rules such as subst may require manual instantiation, if some of
  1272     the unknowns in the rule is a set.
  1273 
  1274   - Higher order unification and forward proofs:
  1275     The proof pattern
  1276 
  1277       have "P (S::'a set)" <...>
  1278       then have "EX S. P S" ..
  1279 
  1280     no longer works (due to the incompleteness of the HO unification
  1281     algorithm) and must be replaced by the pattern
  1282 
  1283       have "EX S. P S"
  1284       proof
  1285         show "P S" <...>
  1286       qed
  1287 
  1288   - Calculational reasoning with subst (or similar rules):
  1289     The proof pattern
  1290 
  1291       have "P (S::'a set)" <...>
  1292       also have "S = T" <...>
  1293       finally have "P T" .
  1294 
  1295     no longer works (for similar reasons as the previous example) and
  1296     must be replaced by something like
  1297 
  1298       have "P (S::'a set)" <...>
  1299       moreover have "S = T" <...>
  1300       ultimately have "P T" by simp
  1301 
  1302   - Tactics or packages written in ML code:
  1303     Code performing pattern matching on types via
  1304 
  1305       Type ("set", [T]) => ...
  1306 
  1307     must be rewritten. Moreover, functions like strip_type or
  1308     binder_types no longer return the right value when applied to a
  1309     type of the form
  1310 
  1311       T1 => ... => Tn => U => bool
  1312 
  1313     rather than
  1314 
  1315       T1 => ... => Tn => U set
  1316 
  1317 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1318 Wellfounded_Relations to theory Wellfounded.
  1319 
  1320 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1321 
  1322 * Class finite no longer treats UNIV as class parameter.  Use class
  1323 enum from theory Library/Enum instead to achieve a similar effect.
  1324 INCOMPATIBILITY.
  1325 
  1326 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1327 and "Cons".  INCOMPATIBILITY.
  1328 
  1329 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1330 Potential INCOMPATIBILITY.
  1331 
  1332 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1333 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1334 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1335 
  1336 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1337 the same name in theory Orderings:
  1338 
  1339   less_trans
  1340   less_linear
  1341   le_imp_less_or_eq
  1342   le_less_trans
  1343   less_le_trans
  1344   less_not_sym
  1345   less_asym
  1346 
  1347 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1348 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1349 and different variable names.
  1350 
  1351 * Library/Option_ord.thy: Canonical order on option type.
  1352 
  1353 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1354 finite maps.
  1355 
  1356 * Library/Countable.thy: Type class for countable types.
  1357 
  1358 * Theory Int: The representation of numerals has changed.  The infix
  1359 operator BIT and the bit datatype with constructors B0 and B1 have
  1360 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1361 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1362 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1363 accordingly.
  1364 
  1365 * Theory Nat: definition of <= and < on natural numbers no longer
  1366 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1367 le_def and less_def have disappeared.  Consider lemmas not_less
  1368 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1369 
  1370 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1371 (whose purpose mainly is for various fold_set functionals) have been
  1372 abandoned in favor of the existing algebraic classes
  1373 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1374 lower_semilattice (resp. upper_semilattice) and linorder.
  1375 INCOMPATIBILITY.
  1376 
  1377 * Theory Transitive_Closure: induct and cases rules now declare proper
  1378 case_names ("base" and "step").  INCOMPATIBILITY.
  1379 
  1380 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1381 lattices.  The form set-specific version is available as
  1382 Inductive.lfp_ordinal_induct_set.
  1383 
  1384 * Renamed theorems "power.simps" to "power_int.simps".
  1385 INCOMPATIBILITY.
  1386 
  1387 * Class semiring_div provides basic abstract properties of semirings
  1388 with division and modulo operations.  Subsumes former class dvd_mod.
  1389 
  1390 * Merged theories IntDef, Numeral and IntArith into unified theory
  1391 Int.  INCOMPATIBILITY.
  1392 
  1393 * Theory Library/Code_Index: type "index" now represents natural
  1394 numbers rather than integers.  INCOMPATIBILITY.
  1395 
  1396 * New class "uminus" with operation "uminus" (split of from class
  1397 "minus" which now only has operation "minus", binary).
  1398 INCOMPATIBILITY.
  1399 
  1400 * Constants "card", "internal_split", "option_map" now with authentic
  1401 syntax.  INCOMPATIBILITY.
  1402 
  1403 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1404 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1405 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1406 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1407 Sup_set_def, le_def, less_def, option_map_def now with object
  1408 equality.  INCOMPATIBILITY.
  1409 
  1410 * Records. Removed K_record, and replaced it by pure lambda term
  1411 %x. c. The simplifier setup is now more robust against eta expansion.
  1412 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1413 
  1414 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1415 
  1416 * Library/ListVector: new theory of arithmetic vector operations.
  1417 
  1418 * Library/Order_Relation: new theory of various orderings as sets of
  1419 pairs.  Defines preorders, partial orders, linear orders and
  1420 well-orders on sets and on types.
  1421 
  1422 
  1423 *** ZF ***
  1424 
  1425 * Renamed some theories to allow to loading both ZF and HOL in the
  1426 same session:
  1427 
  1428   Datatype  -> Datatype_ZF
  1429   Inductive -> Inductive_ZF
  1430   Int       -> Int_ZF
  1431   IntDiv    -> IntDiv_ZF
  1432   Nat       -> Nat_ZF
  1433   List      -> List_ZF
  1434   Main      -> Main_ZF
  1435 
  1436 INCOMPATIBILITY: ZF theories that import individual theories below
  1437 Main might need to be adapted.  Regular theory Main is still
  1438 available, as trivial extension of Main_ZF.
  1439 
  1440 
  1441 *** ML ***
  1442 
  1443 * ML within Isar: antiquotation @{const name} or @{const
  1444 name(typargs)} produces statically-checked Const term.
  1445 
  1446 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1447 (of the same name).  Removed obsolete print command.
  1448 
  1449 * Removed obsolete "use_legacy_bindings" function.
  1450 
  1451 * The ``print mode'' is now a thread-local value derived from a global
  1452 template (the former print_mode reference), thus access becomes
  1453 non-critical.  The global print_mode reference is for session
  1454 management only; user-code should use print_mode_value,
  1455 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1456 
  1457 * Functions system/system_out provide a robust way to invoke external
  1458 shell commands, with propagation of interrupts (requires Poly/ML
  1459 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1460 
  1461 
  1462 *** System ***
  1463 
  1464 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1465 in accordance with Proof General 3.7, which prefers GNU emacs.
  1466 
  1467 * isatool tty runs Isabelle process with plain tty interaction;
  1468 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1469 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1470 
  1471 * isatool browser now works with Cygwin as well, using general
  1472 "javapath" function defined in Isabelle process environment.
  1473 
  1474 * YXML notation provides a simple and efficient alternative to
  1475 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1476 isatool yxml as described in the Isabelle system manual.
  1477 
  1478 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1479 provides general wrapper for managing an Isabelle process in a robust
  1480 fashion, with ``cooked'' output from stdin/stderr.
  1481 
  1482 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1483 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1484 
  1485 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1486 way of changing the user's settings is via
  1487 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1488 script.
  1489 
  1490 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1491 cores of the underlying machine, which is a good starting point for
  1492 optimal performance tuning.  The corresponding usedir option -M allows
  1493 "max" as an alias for "0".  WARNING: does not work on certain versions
  1494 of Mac OS (with Poly/ML 5.1).
  1495 
  1496 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1497 adverse effect of Isabelle flooding interactive front-ends (notably
  1498 ProofGeneral / XEmacs).
  1499 
  1500 
  1501 
  1502 New in Isabelle2007 (November 2007)
  1503 -----------------------------------
  1504 
  1505 *** General ***
  1506 
  1507 * More uniform information about legacy features, notably a
  1508 warning/error of "Legacy feature: ...", depending on the state of the
  1509 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1510 legacy features will disappear eventually.
  1511 
  1512 * Theory syntax: the header format ``theory A = B + C:'' has been
  1513 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1514 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1515 
  1516 * Theory syntax: the old non-Isar theory file format has been
  1517 discontinued altogether.  Note that ML proof scripts may still be used
  1518 with Isar theories; migration is usually quite simple with the ML
  1519 function use_legacy_bindings.  INCOMPATIBILITY.
  1520 
  1521 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1522 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1523 quotes.
  1524 
  1525 * Theory loader: be more serious about observing the static theory
  1526 header specifications (including optional directories), but not the
  1527 accidental file locations of previously successful loads.  The strict
  1528 update policy of former update_thy is now already performed by
  1529 use_thy, so the former has been removed; use_thys updates several
  1530 theories simultaneously, just as 'imports' within a theory header
  1531 specification, but without merging the results.  Potential
  1532 INCOMPATIBILITY: may need to refine theory headers and commands
  1533 ROOT.ML which depend on load order.
  1534 
  1535 * Theory loader: optional support for content-based file
  1536 identification, instead of the traditional scheme of full physical
  1537 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1538 (cf. the system manual).  The new scheme allows to work with
  1539 non-finished theories in persistent session images, such that source
  1540 files may be moved later on without requiring reloads.
  1541 
  1542 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1543 file (with the same base name as the theory) are considered a legacy
  1544 feature, which will disappear eventually. Even now, the theory loader
  1545 no longer maintains dependencies on such files.
  1546 
  1547 * Syntax: the scope for resolving ambiguities via type-inference is
  1548 now limited to individual terms, instead of whole simultaneous
  1549 specifications as before. This greatly reduces the complexity of the
  1550 syntax module and improves flexibility by separating parsing and
  1551 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1552 'fixes' etc.) are required in rare situations.
  1553 
  1554 * Syntax: constants introduced by new-style packages ('definition',
  1555 'abbreviation' etc.) are passed through the syntax module in
  1556 ``authentic mode''. This means that associated mixfix annotations
  1557 really stick to such constants, independently of potential name space
  1558 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1559 trees are represented slightly differently, may need to adapt syntax
  1560 translations accordingly. Use CONST marker in 'translations' and
  1561 @{const_syntax} antiquotation in 'parse_translation' etc.
  1562 
  1563 * Legacy goal package: reduced interface to the bare minimum required
  1564 to keep existing proof scripts running.  Most other user-level
  1565 functions are now part of the OldGoals structure, which is *not* open
  1566 by default (consider isatool expandshort before open OldGoals).
  1567 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1568 these tend to cause confusion about the actual goal (!) context being
  1569 used here, which is not necessarily the same as the_context().
  1570 
  1571 * Command 'find_theorems': supports "*" wild-card in "name:"
  1572 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1573 support a specific search form (see ProofGeneral/CHANGES).
  1574 
  1575 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1576 by default, which means that "prems" (and also "fixed variables") are
  1577 suppressed from proof state output.  Note that the ProofGeneral
  1578 settings mechanism allows to change and save options persistently, but
  1579 older versions of Isabelle will fail to start up if a negative prems
  1580 limit is imposed.
  1581 
  1582 * Local theory targets may be specified by non-nested blocks of
  1583 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1584 contain definitions, theorems etc., including any derived mechanism
  1585 that has been implemented on top of these primitives.  This concept
  1586 generalizes the existing ``theorem (in ...)'' towards more versatility
  1587 and scalability.
  1588 
  1589 * Proof General interface: proper undo of final 'end' command;
  1590 discontinued Isabelle/classic mode (ML proof scripts).
  1591 
  1592 
  1593 *** Document preparation ***
  1594 
  1595 * Added antiquotation @{theory name} which prints the given name,
  1596 after checking that it refers to a valid ancestor theory in the
  1597 current context.
  1598 
  1599 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1600 check the given source text as ML type/structure, printing verbatim.
  1601 
  1602 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1603 "c args == rhs" given in the current context.  (Any number of
  1604 arguments may be given on the LHS.)
  1605 
  1606 
  1607 *** Pure ***
  1608 
  1609 * The 'class' package offers a combination of axclass and locale to
  1610 achieve Haskell-like type classes in Isabelle.  Definitions and
  1611 theorems within a class context produce both relative results (with
  1612 implicit parameters according to the locale context), and polymorphic
  1613 constants with qualified polymorphism (according to the class
  1614 context).  Within the body context of a 'class' target, a separate
  1615 syntax layer ("user space type system") takes care of converting
  1616 between global polymorphic consts and internal locale representation.
  1617 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1618 "isatool doc classes" provides a tutorial.
  1619 
  1620 * Generic code generator framework allows to generate executable
  1621 code for ML and Haskell (including Isabelle classes).  A short usage
  1622 sketch:
  1623 
  1624     internal compilation:
  1625         export_code <list of constants (term syntax)> in SML
  1626     writing SML code to a file:
  1627         export_code <list of constants (term syntax)> in SML <filename>
  1628     writing OCaml code to a file:
  1629         export_code <list of constants (term syntax)> in OCaml <filename>
  1630     writing Haskell code to a bunch of files:
  1631         export_code <list of constants (term syntax)> in Haskell <filename>
  1632 
  1633     evaluating closed propositions to True/False using code generation:
  1634         method ``eval''
  1635 
  1636 Reasonable default setup of framework in HOL.
  1637 
  1638 Theorem attributs for selecting and transforming function equations theorems:
  1639 
  1640     [code fun]:        select a theorem as function equation for a specific constant
  1641     [code fun del]:    deselect a theorem as function equation for a specific constant
  1642     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1643     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1644 
  1645 User-defined serializations (target in {SML, OCaml, Haskell}):
  1646 
  1647     code_const <and-list of constants (term syntax)>
  1648       {(target) <and-list of const target syntax>}+
  1649 
  1650     code_type <and-list of type constructors>
  1651       {(target) <and-list of type target syntax>}+
  1652 
  1653     code_instance <and-list of instances>
  1654       {(target)}+
  1655         where instance ::= <type constructor> :: <class>
  1656 
  1657     code_class <and_list of classes>
  1658       {(target) <and-list of class target syntax>}+
  1659         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1660 
  1661 code_instance and code_class only are effective to target Haskell.
  1662 
  1663 For example usage see src/HOL/ex/Codegenerator.thy and
  1664 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1665 generation from Isabelle/HOL theories is available via "isatool doc
  1666 codegen".
  1667 
  1668 * Code generator: consts in 'consts_code' Isar commands are now
  1669 referred to by usual term syntax (including optional type
  1670 annotations).
  1671 
  1672 * Command 'no_translations' removes translation rules from theory
  1673 syntax.
  1674 
  1675 * Overloaded definitions are now actually checked for acyclic
  1676 dependencies.  The overloading scheme is slightly more general than
  1677 that of Haskell98, although Isabelle does not demand an exact
  1678 correspondence to type class and instance declarations.
  1679 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1680 exotic versions of overloading -- at the discretion of the user!
  1681 
  1682 Polymorphic constants are represented via type arguments, i.e. the
  1683 instantiation that matches an instance against the most general
  1684 declaration given in the signature.  For example, with the declaration
  1685 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1686 as c(nat).  Overloading is essentially simultaneous structural
  1687 recursion over such type arguments.  Incomplete specification patterns
  1688 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1689 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1690 Command 'print_theory' outputs the normalized system of recursive
  1691 equations, see section "definitions".
  1692 
  1693 * Configuration options are maintained within the theory or proof
  1694 context (with name and type bool/int/string), providing a very simple
  1695 interface to a poor-man's version of general context data.  Tools may
  1696 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1697 these values using Config.get etc.  Users may change options via an
  1698 associated attribute of the same name.  This form of context
  1699 declaration works particularly well with commands 'declare' or
  1700 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1701 very easy to avoid global references, which would not observe Isar
  1702 toplevel undo/redo and fail to work with multithreading.
  1703 
  1704 Various global ML references of Pure and HOL have been turned into
  1705 configuration options:
  1706 
  1707   Unify.search_bound		unify_search_bound
  1708   Unify.trace_bound		unify_trace_bound
  1709   Unify.trace_simp		unify_trace_simp
  1710   Unify.trace_types		unify_trace_types
  1711   Simplifier.simp_depth_limit	simp_depth_limit
  1712   Blast.depth_limit		blast_depth_limit
  1713   DatatypeProp.dtK		datatype_distinctness_limit
  1714   fast_arith_neq_limit  	fast_arith_neq_limit
  1715   fast_arith_split_limit	fast_arith_split_limit
  1716 
  1717 * Named collections of theorems may be easily installed as context
  1718 data using the functor NamedThmsFun (see also
  1719 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1720 attributes; there is also a toplevel print command.  This facility is
  1721 just a common case of general context data, which is the preferred way
  1722 for anything more complex than just a list of facts in canonical
  1723 order.
  1724 
  1725 * Isar: command 'declaration' augments a local theory by generic
  1726 declaration functions written in ML.  This enables arbitrary content
  1727 being added to the context, depending on a morphism that tells the
  1728 difference of the original declaration context wrt. the application
  1729 context encountered later on.
  1730 
  1731 * Isar: proper interfaces for simplification procedures.  Command
  1732 'simproc_setup' declares named simprocs (with match patterns, and body
  1733 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1734 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1735 
  1736 * Isar: an extra pair of brackets around attribute declarations
  1737 abbreviates a theorem reference involving an internal dummy fact,
  1738 which will be ignored later --- only the effect of the attribute on
  1739 the background context will persist.  This form of in-place
  1740 declarations is particularly useful with commands like 'declare' and
  1741 'using', for example ``have A using [[simproc a]] by simp''.
  1742 
  1743 * Isar: method "assumption" (and implicit closing of subproofs) now
  1744 takes simple non-atomic goal assumptions into account: after applying
  1745 an assumption as a rule the resulting subgoals are solved by atomic
  1746 assumption steps.  This is particularly useful to finish 'obtain'
  1747 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1748 without referring to the original premise "!!x. P x ==> thesis" in the
  1749 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1750 more permissive.
  1751 
  1752 * Isar: implicit use of prems from the Isar proof context is
  1753 considered a legacy feature.  Common applications like ``have A .''
  1754 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1755 referencing facts explicitly here improves readability and
  1756 maintainability of proof texts.
  1757 
  1758 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1759 the obtained context from the course of reasoning!  For example:
  1760 
  1761   assume "EX x y. A x & B y"   -- "any previous fact"
  1762   then guess x and y by clarify
  1763 
  1764 This technique is potentially adventurous, depending on the facts and
  1765 proof tools being involved here.
  1766 
  1767 * Isar: known facts from the proof context may be specified as literal
  1768 propositions, using ASCII back-quote syntax.  This works wherever
  1769 named facts used to be allowed so far, in proof commands, proof
  1770 methods, attributes etc.  Literal facts are retrieved from the context
  1771 according to unification of type and term parameters.  For example,
  1772 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1773 theorems in the current context, then these are valid literal facts:
  1774 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1775 
  1776 There is also a proof method "fact" which does the same composition
  1777 for explicit goal states, e.g. the following proof texts coincide with
  1778 certain special cases of literal facts:
  1779 
  1780   have "A" by fact                 ==  note `A`
  1781   have "A ==> B" by fact           ==  note `A ==> B`
  1782   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1783   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1784 
  1785 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1786 outer syntax.  Thus symbolic identifiers may be used without
  1787 additional white space in declarations like this: ``assume *: A''.
  1788 
  1789 * Isar: 'print_facts' prints all local facts of the current context,
  1790 both named and unnamed ones.
  1791 
  1792 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1793 
  1794   def x == "t" and y == "u"
  1795 
  1796 * Isar: added command 'unfolding', which is structurally similar to
  1797 'using', but affects both the goal state and facts by unfolding given
  1798 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1799 'unfolded' attribute may be replaced by first-class proof text.
  1800 
  1801 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1802 and command 'unfolding' now all support object-level equalities
  1803 (potentially conditional).  The underlying notion of rewrite rule is
  1804 analogous to the 'rule_format' attribute, but *not* that of the
  1805 Simplifier (which is usually more generous).
  1806 
  1807 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1808 premises of a theorem by n. Useful in conjunction with drule.
  1809 
  1810 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1811 method expression within a sandbox consisting of the first N
  1812 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1813 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1814 simplifies all new goals that emerge from applying rule foo to the
  1815 originally first one.
  1816 
  1817 * Isar: schematic goals are no longer restricted to higher-order
  1818 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1819 expected.
  1820 
  1821 * Isar: the conclusion of a long theorem statement is now either
  1822 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1823 (essentially a disjunction of cases with local parameters and
  1824 assumptions).  The latter allows to express general elimination rules
  1825 adequately; in this notation common elimination rules look like this:
  1826 
  1827   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1828     assumes "EX x. P x"
  1829     obtains x where "P x"
  1830 
  1831   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1832     assumes "A & B"
  1833     obtains A and B
  1834 
  1835   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1836     assumes "A | B"
  1837     obtains
  1838       A
  1839     | B
  1840 
  1841 The subsequent classical rules even refer to the formal "thesis"
  1842 explicitly:
  1843 
  1844   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1845     obtains "~ thesis"
  1846 
  1847   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1848     obtains "thesis ==> something"
  1849 
  1850 The actual proof of an 'obtains' statement is analogous to that of the
  1851 Isar proof element 'obtain', only that there may be several cases.
  1852 Optional case names may be specified in parentheses; these will be
  1853 available both in the present proof and as annotations in the
  1854 resulting rule, for later use with the 'cases' method (cf. attribute
  1855 case_names).
  1856 
  1857 * Isar: the assumptions of a long theorem statement are available as
  1858 "assms" fact in the proof context.  This is more appropriate than the
  1859 (historical) "prems", which refers to all assumptions of the current
  1860 context, including those from the target locale, proof body etc.
  1861 
  1862 * Isar: 'print_statement' prints theorems from the current theory or
  1863 proof context in long statement form, according to the syntax of a
  1864 top-level lemma.
  1865 
  1866 * Isar: 'obtain' takes an optional case name for the local context
  1867 introduction rule (default "that").
  1868 
  1869 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1870 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1871 to occur.
  1872 
  1873 * Pure: syntax "CONST name" produces a fully internalized constant
  1874 according to the current context.  This is particularly useful for
  1875 syntax translations that should refer to internal constant
  1876 representations independently of name spaces.
  1877 
  1878 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1879 instead of "FOO ". This allows multiple binder declarations to coexist
  1880 in the same context.  INCOMPATIBILITY.
  1881 
  1882 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1883 primitive that also works in a locale context (both for constants and
  1884 fixed variables). Type declaration and internal syntactic representation
  1885 of given constants retrieved from the context. Likewise, the
  1886 'no_notation' command allows to remove given syntax annotations from the
  1887 current context.
  1888 
  1889 * Isar/locales: new derived specification elements 'axiomatization',
  1890 'definition', 'abbreviation', which support type-inference, admit
  1891 object-level specifications (equality, equivalence).  See also the
  1892 isar-ref manual.  Examples:
  1893 
  1894   axiomatization
  1895     eq  (infix "===" 50) where
  1896     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1897 
  1898   definition "f x y = x + y + 1"
  1899   definition g where "g x = f x x"
  1900 
  1901   abbreviation
  1902     neq  (infix "=!=" 50) where
  1903     "x =!= y == ~ (x === y)"
  1904 
  1905 These specifications may be also used in a locale context.  Then the
  1906 constants being introduced depend on certain fixed parameters, and the
  1907 constant name is qualified by the locale base name.  An internal
  1908 abbreviation takes care for convenient input and output, making the
  1909 parameters implicit and using the original short name.  See also
  1910 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1911 entities from a monomorphic theory.
  1912 
  1913 Presently, abbreviations are only available 'in' a target locale, but
  1914 not inherited by general import expressions.  Also note that
  1915 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1916 'translations' in common applications.  The "no_abbrevs" print mode
  1917 prevents folding of abbreviations in term output.
  1918 
  1919 Concrete syntax is attached to specified constants in internal form,
  1920 independently of name spaces.  The parse tree representation is
  1921 slightly different -- use 'notation' instead of raw 'syntax', and
  1922 'translations' with explicit "CONST" markup to accommodate this.
  1923 
  1924 * Pure/Isar: unified syntax for new-style specification mechanisms
  1925 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1926 full type inference and dummy patterns ("_").  For example:
  1927 
  1928   definition "K x _ = x"
  1929 
  1930   inductive conj for A B
  1931   where "A ==> B ==> conj A B"
  1932 
  1933 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1934 the current context.  Print mode "no_abbrevs" prevents inversion of
  1935 abbreviations on output.
  1936 
  1937 * Isar/locales: improved parameter handling: use of locales "var" and
  1938 "struct" no longer necessary; - parameter renamings are no longer
  1939 required to be injective.  For example, this allows to define
  1940 endomorphisms as locale endom = homom mult mult h.
  1941 
  1942 * Isar/locales: changed the way locales with predicates are defined.
  1943 Instead of accumulating the specification, the imported expression is
  1944 now an interpretation.  INCOMPATIBILITY: different normal form of
  1945 locale expressions.  In particular, in interpretations of locales with
  1946 predicates, goals repesenting already interpreted fragments are not
  1947 removed automatically.  Use methods `intro_locales' and
  1948 `unfold_locales'; see below.
  1949 
  1950 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1951 provide backward reasoning on locales predicates.  The methods are
  1952 aware of interpretations and discharge corresponding goals.
  1953 `intro_locales' is less aggressive then `unfold_locales' and does not
  1954 unfold predicates to assumptions.
  1955 
  1956 * Isar/locales: the order in which locale fragments are accumulated
  1957 has changed.  This enables to override declarations from fragments due
  1958 to interpretations -- for example, unwanted simp rules.
  1959 
  1960 * Isar/locales: interpretation in theories and proof contexts has been
  1961 extended.  One may now specify (and prove) equations, which are
  1962 unfolded in interpreted theorems.  This is useful for replacing
  1963 defined concepts (constants depending on locale parameters) by
  1964 concepts already existing in the target context.  Example:
  1965 
  1966   interpretation partial_order ["op <= :: [int, int] => bool"]
  1967     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1968 
  1969 Typically, the constant `partial_order.less' is created by a
  1970 definition specification element in the context of locale
  1971 partial_order.
  1972 
  1973 * Method "induct": improved internal context management to support
  1974 local fixes and defines on-the-fly. Thus explicit meta-level
  1975 connectives !!  and ==> are rarely required anymore in inductive goals
  1976 (using object-logic connectives for this purpose has been long
  1977 obsolete anyway). Common proof patterns are explained in
  1978 src/HOL/Induct/Common_Patterns.thy, see also
  1979 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1980 examples.
  1981 
  1982 * Method "induct": improved handling of simultaneous goals. Instead of
  1983 introducing object-level conjunction, the statement is now split into
  1984 several conclusions, while the corresponding symbolic cases are nested
  1985 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1986 see src/HOL/Induct/Common_Patterns.thy, for example.
  1987 
  1988 * Method "induct": mutual induction rules are now specified as a list
  1989 of rule sharing the same induction cases. HOL packages usually provide
  1990 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1991 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1992 mutual induction rules differently, i.e. like this:
  1993 
  1994   (induct rule: foo_bar.inducts)
  1995   (induct set: foo bar)
  1996   (induct pred: foo bar)
  1997   (induct type: foo bar)
  1998 
  1999 The ML function ProjectRule.projections turns old-style rules into the
  2000 new format.
  2001 
  2002 * Method "coinduct": dual of induction, see
  2003 src/HOL/Library/Coinductive_List.thy for various examples.
  2004 
  2005 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2006 considered a legacy feature.
  2007 
  2008 * Attribute "symmetric" produces result with standardized schematic
  2009 variables (index 0).  Potential INCOMPATIBILITY.
  2010 
  2011 * Simplifier: by default the simplifier trace only shows top level
  2012 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2013 default. Thus there is less danger of being flooded by the trace. The
  2014 trace indicates where parts have been suppressed.
  2015   
  2016 * Provers/classical: removed obsolete classical version of elim_format
  2017 attribute; classical elim/dest rules are now treated uniformly when
  2018 manipulating the claset.
  2019 
  2020 * Provers/classical: stricter checks to ensure that supplied intro,
  2021 dest and elim rules are well-formed; dest and elim rules must have at
  2022 least one premise.
  2023 
  2024 * Provers/classical: attributes dest/elim/intro take an optional
  2025 weight argument for the rule (just as the Pure versions).  Weights are
  2026 ignored by automated tools, but determine the search order of single
  2027 rule steps.
  2028 
  2029 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2030 where the body does not mention the bound variable.  Note that dummy
  2031 patterns implicitly depend on their context of bounds, which makes
  2032 "{_. _}" match any set comprehension as expected.  Potential
  2033 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2034 constant "_idtdummy" in the binding position.
  2035 
  2036 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2037 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2038 for example "A -> B" => "Pi A (%_. B)".
  2039 
  2040 * Pure: 'class_deps' command visualizes the subclass relation, using
  2041 the graph browser tool.
  2042 
  2043 * Pure: 'print_theory' now suppresses certain internal declarations by
  2044 default; use '!' option for full details.
  2045 
  2046 
  2047 *** HOL ***
  2048 
  2049 * Method "metis" proves goals by applying the Metis general-purpose
  2050 resolution prover (see also http://gilith.com/software/metis/).
  2051 Examples are in the directory MetisExamples.  WARNING: the
  2052 Isabelle/HOL-Metis integration does not yet work properly with
  2053 multi-threading.
  2054   
  2055 * Command 'sledgehammer' invokes external automatic theorem provers as
  2056 background processes.  It generates calls to the "metis" method if
  2057 successful. These can be pasted into the proof.  Users do not have to
  2058 wait for the automatic provers to return.  WARNING: does not really
  2059 work with multi-threading.
  2060 
  2061 * New "auto_quickcheck" feature tests outermost goal statements for
  2062 potential counter-examples.  Controlled by ML references
  2063 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2064 5000 milliseconds).  Fails silently if statements is outside of
  2065 executable fragment, or any other codgenerator problem occurs.
  2066 
  2067 * New constant "undefined" with axiom "undefined x = undefined".
  2068 
  2069 * Added class "HOL.eq", allowing for code generation with polymorphic
  2070 equality.
  2071 
  2072 * Some renaming of class constants due to canonical name prefixing in
  2073 the new 'class' package:
  2074 
  2075     HOL.abs ~> HOL.abs_class.abs
  2076     HOL.divide ~> HOL.divide_class.divide
  2077     0 ~> HOL.zero_class.zero
  2078     1 ~> HOL.one_class.one
  2079     op + ~> HOL.plus_class.plus
  2080     op - ~> HOL.minus_class.minus
  2081     uminus ~> HOL.minus_class.uminus
  2082     op * ~> HOL.times_class.times
  2083     op < ~> HOL.ord_class.less
  2084     op <= > HOL.ord_class.less_eq
  2085     Nat.power ~> Power.power_class.power
  2086     Nat.size ~> Nat.size_class.size
  2087     Numeral.number_of ~> Numeral.number_class.number_of
  2088     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2089     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2090     Orderings.min ~> Orderings.ord_class.min
  2091     Orderings.max ~> Orderings.ord_class.max
  2092     Divides.op div ~> Divides.div_class.div
  2093     Divides.op mod ~> Divides.div_class.mod
  2094     Divides.op dvd ~> Divides.div_class.dvd
  2095 
  2096 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2097 
  2098 a) User-defined constants using any of the names "plus", "minus",
  2099 "times", "less" or "less_eq". The standard syntax translations for
  2100 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2101 names.
  2102 
  2103 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2104 INCOMPATIBILITY: use more specific names.
  2105 
  2106 c) Permutative equations (e.g. "a + b = b + a")
  2107 Since the change of names also changes the order of terms, permutative
  2108 rewrite rules may get applied in a different order. Experience shows
  2109 that this is rarely the case (only two adaptions in the whole Isabelle
  2110 distribution).  INCOMPATIBILITY: rewrite proofs
  2111 
  2112 d) ML code directly refering to constant names
  2113 This in general only affects hand-written proof tactics, simprocs and
  2114 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2115 Consider using @{const_name} antiquotation.
  2116 
  2117 * New class "default" with associated constant "default".
  2118 
  2119 * Function "sgn" is now overloaded and available on int, real, complex
  2120 (and other numeric types), using class "sgn".  Two possible defs of
  2121 sgn are given as equational assumptions in the classes sgn_if and
  2122 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2123 INCOMPATIBILITY.
  2124 
  2125 * Locale "partial_order" now unified with class "order" (cf. theory
  2126 Orderings), added parameter "less".  INCOMPATIBILITY.
  2127 
  2128 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2129 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2130 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2131 
  2132 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2133 changed order of proof goals in instance proofs.
  2134 
  2135 * The transitivity reasoner for partial and linear orders is set up
  2136 for classes "order" and "linorder".  Instances of the reasoner are available
  2137 in all contexts importing or interpreting the corresponding locales.
  2138 Method "order" invokes the reasoner separately; the reasoner
  2139 is also integrated with the Simplifier as a solver.  Diagnostic
  2140 command 'print_orders' shows the available instances of the reasoner
  2141 in the current context.
  2142 
  2143 * Localized monotonicity predicate in theory "Orderings"; integrated
  2144 lemmas max_of_mono and min_of_mono with this predicate.
  2145 INCOMPATIBILITY.
  2146 
  2147 * Formulation of theorem "dense" changed slightly due to integration
  2148 with new class dense_linear_order.
  2149 
  2150 * Uniform lattice theory development in HOL.
  2151 
  2152     constants "meet" and "join" now named "inf" and "sup"
  2153     constant "Meet" now named "Inf"
  2154 
  2155     classes "meet_semilorder" and "join_semilorder" now named
  2156       "lower_semilattice" and "upper_semilattice"
  2157     class "lorder" now named "lattice"
  2158     class "comp_lat" now named "complete_lattice"
  2159 
  2160     Instantiation of lattice classes allows explicit definitions
  2161     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2162 
  2163   INCOMPATIBILITY.  Theorem renames:
  2164 
  2165     meet_left_le            ~> inf_le1
  2166     meet_right_le           ~> inf_le2
  2167     join_left_le            ~> sup_ge1
  2168     join_right_le           ~> sup_ge2
  2169     meet_join_le            ~> inf_sup_ord
  2170     le_meetI                ~> le_infI
  2171     join_leI                ~> le_supI
  2172     le_meet                 ~> le_inf_iff
  2173     le_join                 ~> ge_sup_conv
  2174     meet_idempotent         ~> inf_idem
  2175     join_idempotent         ~> sup_idem
  2176     meet_comm               ~> inf_commute
  2177     join_comm               ~> sup_commute
  2178     meet_leI1               ~> le_infI1
  2179     meet_leI2               ~> le_infI2
  2180     le_joinI1               ~> le_supI1
  2181     le_joinI2               ~> le_supI2
  2182     meet_assoc              ~> inf_assoc
  2183     join_assoc              ~> sup_assoc
  2184     meet_left_comm          ~> inf_left_commute
  2185     meet_left_idempotent    ~> inf_left_idem
  2186     join_left_comm          ~> sup_left_commute
  2187     join_left_idempotent    ~> sup_left_idem
  2188     meet_aci                ~> inf_aci
  2189     join_aci                ~> sup_aci
  2190     le_def_meet             ~> le_iff_inf
  2191     le_def_join             ~> le_iff_sup
  2192     join_absorp2            ~> sup_absorb2
  2193     join_absorp1            ~> sup_absorb1
  2194     meet_absorp1            ~> inf_absorb1
  2195     meet_absorp2            ~> inf_absorb2
  2196     meet_join_absorp        ~> inf_sup_absorb
  2197     join_meet_absorp        ~> sup_inf_absorb
  2198     distrib_join_le         ~> distrib_sup_le
  2199     distrib_meet_le         ~> distrib_inf_le
  2200 
  2201     add_meet_distrib_left   ~> add_inf_distrib_left
  2202     add_join_distrib_left   ~> add_sup_distrib_left
  2203     is_join_neg_meet        ~> is_join_neg_inf
  2204     is_meet_neg_join        ~> is_meet_neg_sup
  2205     add_meet_distrib_right  ~> add_inf_distrib_right
  2206     add_join_distrib_right  ~> add_sup_distrib_right
  2207     add_meet_join_distribs  ~> add_sup_inf_distribs
  2208     join_eq_neg_meet        ~> sup_eq_neg_inf
  2209     meet_eq_neg_join        ~> inf_eq_neg_sup
  2210     add_eq_meet_join        ~> add_eq_inf_sup
  2211     meet_0_imp_0            ~> inf_0_imp_0
  2212     join_0_imp_0            ~> sup_0_imp_0
  2213     meet_0_eq_0             ~> inf_0_eq_0
  2214     join_0_eq_0             ~> sup_0_eq_0
  2215     neg_meet_eq_join        ~> neg_inf_eq_sup
  2216     neg_join_eq_meet        ~> neg_sup_eq_inf
  2217     join_eq_if              ~> sup_eq_if
  2218 
  2219     mono_meet               ~> mono_inf
  2220     mono_join               ~> mono_sup
  2221     meet_bool_eq            ~> inf_bool_eq
  2222     join_bool_eq            ~> sup_bool_eq
  2223     meet_fun_eq             ~> inf_fun_eq
  2224     join_fun_eq             ~> sup_fun_eq
  2225     meet_set_eq             ~> inf_set_eq
  2226     join_set_eq             ~> sup_set_eq
  2227     meet1_iff               ~> inf1_iff
  2228     meet2_iff               ~> inf2_iff
  2229     meet1I                  ~> inf1I
  2230     meet2I                  ~> inf2I
  2231     meet1D1                 ~> inf1D1
  2232     meet2D1                 ~> inf2D1
  2233     meet1D2                 ~> inf1D2
  2234     meet2D2                 ~> inf2D2
  2235     meet1E                  ~> inf1E
  2236     meet2E                  ~> inf2E
  2237     join1_iff               ~> sup1_iff
  2238     join2_iff               ~> sup2_iff
  2239     join1I1                 ~> sup1I1
  2240     join2I1                 ~> sup2I1
  2241     join1I1                 ~> sup1I1
  2242     join2I2                 ~> sup1I2
  2243     join1CI                 ~> sup1CI
  2244     join2CI                 ~> sup2CI
  2245     join1E                  ~> sup1E
  2246     join2E                  ~> sup2E
  2247 
  2248     is_meet_Meet            ~> is_meet_Inf
  2249     Meet_bool_def           ~> Inf_bool_def
  2250     Meet_fun_def            ~> Inf_fun_def
  2251     Meet_greatest           ~> Inf_greatest
  2252     Meet_lower              ~> Inf_lower
  2253     Meet_set_def            ~> Inf_set_def
  2254 
  2255     Sup_def                 ~> Sup_Inf
  2256     Sup_bool_eq             ~> Sup_bool_def
  2257     Sup_fun_eq              ~> Sup_fun_def
  2258     Sup_set_eq              ~> Sup_set_def
  2259 
  2260     listsp_meetI            ~> listsp_infI
  2261     listsp_meet_eq          ~> listsp_inf_eq
  2262 
  2263     meet_min                ~> inf_min
  2264     join_max                ~> sup_max
  2265 
  2266 * Added syntactic class "size"; overloaded constant "size" now has
  2267 type "'a::size ==> bool"
  2268 
  2269 * Internal reorganisation of `size' of datatypes: size theorems
  2270 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2271 simplification rules by default!); theorems "prod.size" now named
  2272 "*.size".
  2273 
  2274 * Class "div" now inherits from class "times" rather than "type".
  2275 INCOMPATIBILITY.
  2276 
  2277 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2278 Linorder etc.  have disappeared; operations defined in terms of
  2279 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2280 
  2281 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2282 
  2283 * HOL-Word: New extensive library and type for generic, fixed size
  2284 machine words, with arithemtic, bit-wise, shifting and rotating
  2285 operations, reflection into int, nat, and bool lists, automation for
  2286 linear arithmetic (by automatic reflection into nat or int), including
  2287 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2288 arithmetic type classes, supporting automatic simplification of
  2289 numerals on all operations.
  2290 
  2291 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2292 
  2293 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2294 
  2295 * Code generator library theories:
  2296   - Code_Integer represents HOL integers by big integer literals in target
  2297     languages.
  2298   - Code_Char represents HOL characters by character literals in target
  2299     languages.
  2300   - Code_Char_chr like Code_Char, but also offers treatment of character
  2301     codes; includes Code_Integer.
  2302   - Executable_Set allows to generate code for finite sets using lists.
  2303   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2304     denominator).
  2305   - Executable_Real implements a subset of real numbers, namly those
  2306     representable by rational numbers.
  2307   - Efficient_Nat implements natural numbers by integers, which in general will
  2308     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2309     includes Code_Integer.
  2310   - Code_Index provides an additional datatype index which is mapped to
  2311     target-language built-in integers.
  2312   - Code_Message provides an additional datatype message_string which is isomorphic to
  2313     strings; messages are mapped to target-language strings.
  2314 
  2315 * New package for inductive predicates
  2316 
  2317   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2318 
  2319     inductive
  2320       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2321       for z_1 :: U_1 and ... and z_n :: U_m
  2322     where
  2323       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2324     | ...
  2325 
  2326   with full support for type-inference, rather than
  2327 
  2328     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2329 
  2330     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2331     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2332 
  2333     inductive "s z_1 ... z_m"
  2334     intros
  2335       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2336       ...
  2337 
  2338   For backward compatibility, there is a wrapper allowing inductive
  2339   sets to be defined with the new package via
  2340 
  2341     inductive_set
  2342       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2343       for z_1 :: U_1 and ... and z_n :: U_m
  2344     where
  2345       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2346     | ...
  2347 
  2348   or
  2349 
  2350     inductive_set
  2351       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2352       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2353       for z_1 :: U_1 and ... and z_n :: U_m
  2354     where
  2355       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2356     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2357     | ...
  2358 
  2359   if the additional syntax "p ..." is required.
  2360 
  2361   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2362   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2363 
  2364   INCOMPATIBILITIES:
  2365 
  2366   - Since declaration and definition of inductive sets or predicates
  2367     is no longer separated, abbreviations involving the newly
  2368     introduced sets or predicates must be specified together with the
  2369     introduction rules after the 'where' keyword (see above), rather
  2370     than before the actual inductive definition.
  2371 
  2372   - The variables in induction and elimination rules are now
  2373     quantified in the order of their occurrence in the introduction
  2374     rules, rather than in alphabetical order. Since this may break
  2375     some proofs, these proofs either have to be repaired, e.g. by
  2376     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2377     statements of the form
  2378 
  2379       case (rule_i a_i_1 ... a_i_{k_i})
  2380 
  2381     or the old order of quantification has to be restored by explicitly adding
  2382     meta-level quantifiers in the introduction rules, i.e.
  2383 
  2384       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2385 
  2386   - The format of the elimination rules is now
  2387 
  2388       p z_1 ... z_m x_1 ... x_n ==>
  2389         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2390         ==> ... ==> P
  2391 
  2392     for predicates and
  2393 
  2394       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2395         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2396         ==> ... ==> P
  2397 
  2398     for sets rather than
  2399 
  2400       x : s z_1 ... z_m ==>
  2401         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2402         ==> ... ==> P
  2403 
  2404     This may require terms in goals to be expanded to n-tuples
  2405     (e.g. using case_tac or simplification with the split_paired_all
  2406     rule) before the above elimination rule is applicable.
  2407 
  2408   - The elimination or case analysis rules for (mutually) inductive
  2409     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2410     list of rules "p_1_..._p_k.elims" is no longer available.
  2411 
  2412 * New package "function"/"fun" for general recursive functions,
  2413 supporting mutual and nested recursion, definitions in local contexts,
  2414 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2415 for small examples, and the separate tutorial on the function
  2416 package. The old recdef "package" is still available as before, but
  2417 users are encouraged to use the new package.
  2418 
  2419 * Method "lexicographic_order" automatically synthesizes termination
  2420 relations as lexicographic combinations of size measures. 
  2421 
  2422 * Case-expressions allow arbitrary constructor-patterns (including
  2423 "_") and take their order into account, like in functional
  2424 programming.  Internally, this is translated into nested
  2425 case-expressions; missing cases are added and mapped to the predefined
  2426 constant "undefined". In complicated cases printing may no longer show
  2427 the original input but the internal form. Lambda-abstractions allow
  2428 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2429 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2430 variable.
  2431 
  2432 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2433 is an abbreviation for "of_nat :: nat => int". The simplification
  2434 rules for "of_nat" have been changed to work like "int" did
  2435 previously.  Potential INCOMPATIBILITY:
  2436   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2437   - of_nat_diff and of_nat_mult are no longer default simp rules
  2438 
  2439 * Method "algebra" solves polynomial equations over (semi)rings using
  2440 Groebner bases. The (semi)ring structure is defined by locales and the
  2441 tool setup depends on that generic context. Installing the method for
  2442 a specific type involves instantiating the locale and possibly adding
  2443 declarations for computation on the coefficients.  The method is
  2444 already instantiated for natural numbers and for the axiomatic class
  2445 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2446 CALCULEMUS 2007 for the general principles underlying this
  2447 architecture of context-aware proof-tools.
  2448 
  2449 * Method "ferrack" implements quantifier elimination over
  2450 special-purpose dense linear orders using locales (analogous to
  2451 "algebra"). The method is already installed for class
  2452 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2453 rat, etc.
  2454 
  2455 * Former constant "List.op @" now named "List.append".  Use ML
  2456 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2457 circumvent possible incompatibilities when working on ML level.
  2458 
  2459 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2460 
  2461 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2462 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2463 
  2464 * New syntax for Haskell-like list comprehension (input only), eg.
  2465 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2466 
  2467 * The special syntax for function "filter" has changed from [x :
  2468 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2469 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2470 
  2471 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2472 defined on nat only, as an abbreviation for [a..<Suc b]
  2473 INCOMPATIBILITY.
  2474 
  2475 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2476 
  2477 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2478 
  2479 * New lemma collection field_simps (an extension of ring_simps) for
  2480 manipulating (in)equations involving division. Multiplies with all
  2481 denominators that can be proved to be non-zero (in equations) or
  2482 positive/negative (in inequations).
  2483 
  2484 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2485 have been improved and renamed to ring_simps, group_simps and
  2486 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2487 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2488 
  2489 * Theory Library/Commutative_Ring: switched from recdef to function
  2490 package; constants add, mul, pow now curried.  Infix syntax for
  2491 algebraic operations.
  2492 
  2493 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2494 INCOMPATIBILITY.
  2495 
  2496 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2497 INCOMPATIBILITY.
  2498 
  2499 * HOL/records: generalised field-update to take a function on the
  2500 field rather than the new value: r(|A := x|) is translated to A_update
  2501 (K x) r The K-combinator that is internally used is called K_record.
  2502 INCOMPATIBILITY: Usage of the plain update functions has to be
  2503 adapted.
  2504  
  2505 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2506 * x = 0, which are required for a semiring.  Richer structures do not
  2507 inherit from semiring_0 anymore, because this property is a theorem
  2508 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2509 there is more to prove, but this is mostly trivial.
  2510 
  2511 * Class "recpower" is generalized to arbitrary monoids, not just
  2512 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2513 commutativity or semiring properties additionally.
  2514 
  2515 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2516 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2517 better use 'abbreviation'.
  2518 
  2519 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2520 
  2521 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2522 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2523 significant changes for setting up numeral syntax for types:
  2524   - New constants Numeral.pred and Numeral.succ instead
  2525       of former Numeral.bin_pred and Numeral.bin_succ.
  2526   - Use integer operations instead of bin_add, bin_mult and so on.
  2527   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2528   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2529 
  2530 See src/HOL/Integ/IntArith.thy for an example setup.
  2531 
  2532 * Command 'normal_form' computes the normal form of a term that may
  2533 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2534 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2535 heavy-duty computations because the functions are compiled to ML
  2536 first.  Correspondingly, a method "normalization" is provided.  See
  2537 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2538 
  2539 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2540 25 like -->); output depends on the "iff" print_mode, the default is
  2541 "A = B" (with priority 50).
  2542 
  2543 * Relations less (<) and less_eq (<=) are also available on type bool.
  2544 Modified syntax to disallow nesting without explicit parentheses,
  2545 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2546 INCOMPATIBILITY.
  2547 
  2548 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2549 
  2550 * Relation composition operator "op O" now has precedence 75 and binds
  2551 stronger than union and intersection. INCOMPATIBILITY.
  2552 
  2553 * The old set interval syntax "{m..n(}" (and relatives) has been
  2554 removed.  Use "{m..<n}" (and relatives) instead.
  2555 
  2556 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2557 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2558 ``declare [[simproc del: neq]]''.
  2559 
  2560 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2561 True/False.
  2562 
  2563 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2564 
  2565 * Theorem setsum_mult renamed to setsum_right_distrib.
  2566 
  2567 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2568 ``rule'' method.
  2569 
  2570 * Reimplemented methods "sat" and "satx", with several improvements:
  2571 goals no longer need to be stated as "<prems> ==> False", equivalences
  2572 (i.e. "=" on type bool) are handled, variable names of the form
  2573 "lit_<n>" are no longer reserved, significant speedup.
  2574 
  2575 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2576 zChaff is still supported as well.
  2577 
  2578 * 'inductive' and 'datatype': provide projections of mutual rules,
  2579 bundled as foo_bar.inducts;
  2580 
  2581 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2582 Library.
  2583 
  2584 * Library: moved theory Accessible_Part to main HOL.
  2585 
  2586 * Library: added theory Coinductive_List of potentially infinite lists
  2587 as greatest fixed-point.
  2588 
  2589 * Library: added theory AssocList which implements (finite) maps as
  2590 association lists.
  2591 
  2592 * Method "evaluation" solves goals (i.e. a boolean expression)
  2593 efficiently by compiling it to ML.  The goal is "proved" (via an
  2594 oracle) if it evaluates to True.
  2595 
  2596 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2597 also when invoked by the simplifier.  This results in the Simplifier
  2598 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2599 Configuration option fast_arith_split_limit=0 recovers the old
  2600 behavior.
  2601 
  2602 * Support for hex (0x20) and binary (0b1001) numerals.
  2603 
  2604 * New method: reify eqs (t), where eqs are equations for an
  2605 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2606 parameter, computes a term s::'b and a list xs::'a list and proves the
  2607 theorem I xs s = t. This is also known as reification or quoting. The
  2608 resulting theorem is applied to the subgoal to substitute t with I xs
  2609 s.  If t is omitted, the subgoal itself is reified.
  2610 
  2611 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2612 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2613 where f is supposed to be a computable function (in the sense of code
  2614 generattion). The method uses reify to compute s and xs as above then
  2615 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2616 r and finally gets the theorem t = r, which is again applied to the
  2617 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2618 
  2619 * Reflection: Automatic reification now handels binding, an example is
  2620 available in src/HOL/ex/ReflectionEx.thy
  2621 
  2622 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2623 command 'statespace' that is similar to 'record', but introduces an
  2624 abstract specification based on the locale infrastructure instead of
  2625 HOL types.  This leads to extra flexibility in composing state spaces,
  2626 in particular multiple inheritance and renaming of components.
  2627 
  2628 
  2629 *** HOL-Complex ***
  2630 
  2631 * Hyperreal: Functions root and sqrt are now defined on negative real
  2632 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2633 Nonnegativity side conditions have been removed from many lemmas, so
  2634 that more subgoals may now be solved by simplification; potential
  2635 INCOMPATIBILITY.
  2636 
  2637 * Real: new type classes formalize real normed vector spaces and
  2638 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2639 and norm :: 'a => real.
  2640 
  2641 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2642 reals into other types. The overloaded constant Reals :: 'a set is now
  2643 defined as range of_real; potential INCOMPATIBILITY.
  2644 
  2645 * Real: proper support for ML code generation, including 'quickcheck'.
  2646 Reals are implemented as arbitrary precision rationals.
  2647 
  2648 * Hyperreal: Several constants that previously worked only for the
  2649 reals have been generalized, so they now work over arbitrary vector
  2650 spaces. Type annotations may need to be added in some cases; potential
  2651 INCOMPATIBILITY.
  2652 
  2653   Infinitesimal  :: ('a::real_normed_vector) star set
  2654   HFinite        :: ('a::real_normed_vector) star set
  2655   HInfinite      :: ('a::real_normed_vector) star set
  2656   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2657   monad          :: ('a::real_normed_vector) star => 'a star set
  2658   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2659   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2660   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2661   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2662   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2663   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2664   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2665   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2666   sgn            :: 'a::real_normed_vector => 'a
  2667   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2668 
  2669 * Complex: Some complex-specific constants are now abbreviations for
  2670 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2671 hnorm.  Other constants have been entirely removed in favor of the
  2672 polymorphic versions (INCOMPATIBILITY):
  2673 
  2674   approx        <-- capprox
  2675   HFinite       <-- CFinite
  2676   HInfinite     <-- CInfinite
  2677   Infinitesimal <-- CInfinitesimal
  2678   monad         <-- cmonad
  2679   galaxy        <-- cgalaxy
  2680   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2681   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2682   (ns)deriv     <-- (ns)cderiv
  2683 
  2684 
  2685 *** HOL-Algebra ***
  2686 
  2687 * Formalisation of ideals and the quotient construction over rings.
  2688 
  2689 * Order and lattice theory no longer based on records.
  2690 INCOMPATIBILITY.
  2691 
  2692 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2693 greatest_closed.  INCOMPATIBILITY.
  2694 
  2695 * Method algebra is now set up via an attribute.  For examples see
  2696 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2697 of algebraic structures.
  2698 
  2699 * Renamed theory CRing to Ring.
  2700 
  2701 
  2702 *** HOL-Nominal ***
  2703 
  2704 * Substantial, yet incomplete support for nominal datatypes (binding
  2705 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2706 src/HOL/Nominal/Examples.  Prospective users should consult
  2707 http://isabelle.in.tum.de/nominal/
  2708 
  2709 
  2710 *** ML ***
  2711 
  2712 * ML basics: just one true type int, which coincides with IntInf.int
  2713 (even on SML/NJ).
  2714 
  2715 * ML within Isar: antiquotations allow to embed statically-checked
  2716 formal entities in the source, referring to the context available at
  2717 compile-time.  For example:
  2718 
  2719 ML {* @{sort "{zero,one}"} *}
  2720 ML {* @{typ "'a => 'b"} *}
  2721 ML {* @{term "%x. x"} *}
  2722 ML {* @{prop "x == y"} *}
  2723 ML {* @{ctyp "'a => 'b"} *}
  2724 ML {* @{cterm "%x. x"} *}
  2725 ML {* @{cprop "x == y"} *}
  2726 ML {* @{thm asm_rl} *}
  2727 ML {* @{thms asm_rl} *}
  2728 ML {* @{type_name c} *}
  2729 ML {* @{type_syntax c} *}
  2730 ML {* @{const_name c} *}
  2731 ML {* @{const_syntax c} *}
  2732 ML {* @{context} *}
  2733 ML {* @{theory} *}
  2734 ML {* @{theory Pure} *}
  2735 ML {* @{theory_ref} *}
  2736 ML {* @{theory_ref Pure} *}
  2737 ML {* @{simpset} *}
  2738 ML {* @{claset} *}
  2739 ML {* @{clasimpset} *}
  2740 
  2741 The same works for sources being ``used'' within an Isar context.
  2742 
  2743 * ML in Isar: improved error reporting; extra verbosity with
  2744 ML_Context.trace enabled.
  2745 
  2746 * Pure/General/table.ML: the join operations now works via exceptions
  2747 DUP/SAME instead of type option. This is simpler in simple cases, and
  2748 admits slightly more efficient complex applications.
  2749 
  2750 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2751 use Context.generic instead of just theory.
  2752 
  2753 * Pure: datatype Context.generic joins theory/Proof.context and
  2754 provides some facilities for code that works in either kind of
  2755 context, notably GenericDataFun for uniform theory and proof data.
  2756 
  2757 * Pure: simplified internal attribute type, which is now always
  2758 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2759 local (Proof.context) attributes have been discontinued, while
  2760 minimizing code duplication. Thm.rule_attribute and
  2761 Thm.declaration_attribute build canonical attributes; see also structure
  2762 Context for further operations on Context.generic, notably
  2763 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2764 declarations and definitions.
  2765 
  2766 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2767 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2768 init only required for impure data. INCOMPATIBILITY: empty really need
  2769 to be empty (no dependencies on theory content!)
  2770 
  2771 * Pure/kernel: consts certification ignores sort constraints given in
  2772 signature declarations. (This information is not relevant to the
  2773 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2774 potential INCOMPATIBILITY.
  2775 
  2776 * Pure: axiomatic type classes are now purely definitional, with
  2777 explicit proofs of class axioms and super class relations performed
  2778 internally. See Pure/axclass.ML for the main internal interfaces --
  2779 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2780 AxClass.axiomatize_class/classrel/arity supersede
  2781 Sign.add_classes/classrel/arities.
  2782 
  2783 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2784 global/local versions on theory vs. Proof.context have been
  2785 discontinued; Attrib.syntax and Method.syntax have been adapted
  2786 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2787 attributes, methods, etc.
  2788 
  2789 * Pure: several functions of signature "... -> theory -> theory * ..."
  2790 have been reoriented to "... -> theory -> ... * theory" in order to
  2791 allow natural usage in combination with the ||>, ||>>, |-> and
  2792 fold_map combinators.
  2793 
  2794 * Pure: official theorem names (closed derivations) and additional
  2795 comments (tags) are now strictly separate.  Name hints -- which are
  2796 maintained as tags -- may be attached any time without affecting the
  2797 derivation.
  2798 
  2799 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2800 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2801 achieve the old behaviour.
  2802 
  2803 * Pure: the "Goal" constant is now called "prop", supporting a
  2804 slightly more general idea of ``protecting'' meta-level rule
  2805 statements.
  2806 
  2807 * Pure: Logic.(un)varify only works in a global context, which is now
  2808 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2809 Logic.legacy_(un)varify as temporary workaround.
  2810 
  2811 * Pure: structure Name provides scalable operations for generating
  2812 internal variable names, notably Name.variants etc.  This replaces
  2813 some popular functions from term.ML:
  2814 
  2815   Term.variant		->  Name.variant
  2816   Term.variantlist	->  Name.variant_list
  2817   Term.invent_names	->  Name.invent_list
  2818 
  2819 Note that low-level renaming rarely occurs in new code -- operations
  2820 from structure Variable are used instead (see below).
  2821 
  2822 * Pure: structure Variable provides fundamental operations for proper
  2823 treatment of fixed/schematic variables in a context.  For example,
  2824 Variable.import introduces fixes for schematics of given facts and
  2825 Variable.export reverses the effect (up to renaming) -- this replaces
  2826 various freeze_thaw operations.
  2827 
  2828 * Pure: structure Goal provides simple interfaces for
  2829 init/conclude/finish and tactical prove operations (replacing former
  2830 Tactic.prove).  Goal.prove is the canonical way to prove results
  2831 within a given context; Goal.prove_global is a degraded version for
  2832 theory level goals, including a global Drule.standard.  Note that
  2833 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2834 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2835 in a locale context).
  2836 
  2837 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2838 and type checking (Syntax.check_term etc.), with common combinations
  2839 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2840 which are considered legacy and await removal.
  2841 
  2842 * Pure/Syntax: generic interfaces for type unchecking
  2843 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2844 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2845 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2846 available for convenience, but refer to the very same operations using
  2847 a mere theory instead of a full context.
  2848 
  2849 * Isar: simplified treatment of user-level errors, using exception
  2850 ERROR of string uniformly.  Function error now merely raises ERROR,
  2851 without any side effect on output channels.  The Isar toplevel takes
  2852 care of proper display of ERROR exceptions.  ML code may use plain
  2853 handle/can/try; cat_error may be used to concatenate errors like this:
  2854 
  2855   ... handle ERROR msg => cat_error msg "..."
  2856 
  2857 Toplevel ML code (run directly or through the Isar toplevel) may be
  2858 embedded into the Isar toplevel with exception display/debug like
  2859 this:
  2860 
  2861   Isar.toplevel (fn () => ...)
  2862 
  2863 INCOMPATIBILITY, removed special transform_error facilities, removed
  2864 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2865 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2866 -- use plain ERROR instead.
  2867 
  2868 * Isar: theory setup now has type (theory -> theory), instead of a
  2869 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2870 
  2871 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2872 ProofContext.debug/verbose flags.
  2873 
  2874 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2875 theory before entering a proof state.  Transactions now always see a
  2876 quasi-functional intermediate checkpoint, both in interactive and
  2877 batch mode.
  2878 
  2879 * Isar: simplified interfaces for outer syntax.  Renamed
  2880 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2881 OuterSyntax.add_parsers -- this functionality is now included in
  2882 OuterSyntax.command etc.  INCOMPATIBILITY.
  2883 
  2884 * Simplifier: the simpset of a running simplification process now
  2885 contains a proof context (cf. Simplifier.the_context), which is the
  2886 very context that the initial simpset has been retrieved from (by
  2887 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2888 (solver, looper etc.) may depend on arbitrary proof data.
  2889 
  2890 * Simplifier.inherit_context inherits the proof context (plus the
  2891 local bounds) of the current simplification process; any simproc
  2892 etc. that calls the Simplifier recursively should do this!  Removed
  2893 former Simplifier.inherit_bounds, which is already included here --
  2894 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2895 specify an explicit context using Simplifier.context/theory_context.
  2896 
  2897 * Simplifier/Classical Reasoner: more abstract interfaces
  2898 change_simpset/claset for modifying the simpset/claset reference of a
  2899 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2900 INCOMPATIBILITY.
  2901 
  2902 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2903 "Trueprop" etc.
  2904 
  2905 
  2906 *** System ***
  2907 
  2908 * settings: the default heap location within ISABELLE_HOME_USER now
  2909 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2910 Isabelle installations.
  2911 
  2912 * isabelle-process: option -S (secure mode) disables some critical
  2913 operations, notably runtime compilation and evaluation of ML source
  2914 code.
  2915 
  2916 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2917 
  2918 * Support for parallel execution, using native multicore support of
  2919 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2920 independent theories, according to the given theory header
  2921 specifications. The maximum number of worker threads is specified via
  2922 usedir option -M or the "max-threads" setting in Proof General. A
  2923 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2924 to 6 on a 8-core machine.  User-code needs to observe certain
  2925 guidelines for thread-safe programming, see appendix A in the Isar
  2926 Implementation manual.
  2927 
  2928 
  2929 
  2930 New in Isabelle2005 (October 2005)
  2931 ----------------------------------
  2932 
  2933 *** General ***
  2934 
  2935 * Theory headers: the new header syntax for Isar theories is
  2936 
  2937   theory <name>
  2938   imports <theory1> ... <theoryN>
  2939   uses <file1> ... <fileM>
  2940   begin
  2941 
  2942 where the 'uses' part is optional.  The previous syntax
  2943 
  2944   theory <name> = <theory1> + ... + <theoryN>:
  2945 
  2946 will disappear in the next release.  Use isatool fixheaders to convert
  2947 existing theory files.  Note that there is no change in ancient
  2948 non-Isar theories now, but these will disappear soon.
  2949 
  2950 * Theory loader: parent theories can now also be referred to via
  2951 relative and absolute paths.
  2952 
  2953 * Command 'find_theorems' searches for a list of criteria instead of a
  2954 list of constants. Known criteria are: intro, elim, dest, name:string,
  2955 simp:term, and any term. Criteria can be preceded by '-' to select
  2956 theorems that do not match. Intro, elim, dest select theorems that
  2957 match the current goal, name:s selects theorems whose fully qualified
  2958 name contain s, and simp:term selects all simplification rules whose
  2959 lhs match term.  Any other term is interpreted as pattern and selects
  2960 all theorems matching the pattern. Available in ProofGeneral under
  2961 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2962 
  2963   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2964 
  2965 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2966 matching the current goal as introduction rule and not having "HOL."
  2967 in their name (i.e. not being defined in theory HOL).
  2968 
  2969 * Command 'thms_containing' has been discontinued in favour of
  2970 'find_theorems'; INCOMPATIBILITY.
  2971 
  2972 * Communication with Proof General is now 8bit clean, which means that
  2973 Unicode text in UTF-8 encoding may be used within theory texts (both
  2974 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2975 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2976 
  2977   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2978   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2979 
  2980 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2981 Classical Reasoner.  Typical big applications run around 2 times
  2982 faster.
  2983 
  2984 
  2985 *** Document preparation ***
  2986 
  2987 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2988 of raw sources.  Only those symbols that do not require additional
  2989 LaTeX packages (depending on comments in isabellesym.sty) are
  2990 displayed properly, everything else is left verbatim.  isatool display
  2991 and isatool print are used as front ends (these are subject to the
  2992 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2993 
  2994 * Command tags control specific markup of certain regions of text,
  2995 notably folding and hiding.  Predefined tags include "theory" (for
  2996 theory begin and end), "proof" for proof commands, and "ML" for
  2997 commands involving ML code; the additional tags "visible" and
  2998 "invisible" are unused by default.  Users may give explicit tag
  2999 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3000 interpretation of tags is determined by the LaTeX job during document
  3001 preparation: see option -V of isatool usedir, or options -n and -t of
  3002 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3003 \isadroptag.
  3004 
  3005 Several document versions may be produced at the same time via isatool
  3006 usedir (the generated index.html will link all of them).  Typical
  3007 specifications include ''-V document=theory,proof,ML'' to present
  3008 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3009 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3010 these parts without any formal replacement text.  The Isabelle site
  3011 default settings produce ''document'' and ''outline'' versions as
  3012 specified above.
  3013 
  3014 * Several new antiquotations:
  3015 
  3016   @{term_type term} prints a term with its type annotated;
  3017 
  3018   @{typeof term} prints the type of a term;
  3019 
  3020   @{const const} is the same as @{term const}, but checks that the
  3021   argument is a known logical constant;
  3022 
  3023   @{term_style style term} and @{thm_style style thm} print a term or
  3024   theorem applying a "style" to it
  3025 
  3026   @{ML text}
  3027 
  3028 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3029 definitions, equations, inequations etc., 'concl' printing only the
  3030 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3031 to print the specified premise.  TermStyle.add_style provides an ML
  3032 interface for introducing further styles.  See also the "LaTeX Sugar"
  3033 document practical applications.  The ML antiquotation prints
  3034 type-checked ML expressions verbatim.
  3035 
  3036 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3037 and 'text' support optional locale specification '(in loc)', which
  3038 specifies the default context for interpreting antiquotations.  For
  3039 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3040 
  3041 * Option 'locale=NAME' of antiquotations specifies an alternative
  3042 context interpreting the subsequent argument.  For example: @{thm
  3043 [locale=lattice] inf_assoc}.
  3044 
  3045 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3046 a proof context.
  3047 
  3048 * Proper output of antiquotations for theory commands involving a
  3049 proof context (such as 'locale' or 'theorem (in loc) ...').
  3050 
  3051 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3052 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3053 
  3054 * isatool usedir: new option -C (default true) controls whether option
  3055 -D should include a copy of the original document directory; -C false
  3056 prevents unwanted effects such as copying of administrative CVS data.
  3057 
  3058 
  3059 *** Pure ***
  3060 
  3061 * Considerably improved version of 'constdefs' command.  Now performs
  3062 automatic type-inference of declared constants; additional support for
  3063 local structure declarations (cf. locales and HOL records), see also
  3064 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3065 sequential dependencies of definitions within a single 'constdefs'
  3066 section; moreover, the declared name needs to be an identifier.  If
  3067 all fails, consider to fall back on 'consts' and 'defs' separately.
  3068 
  3069 * Improved indexed syntax and implicit structures.  First of all,
  3070 indexed syntax provides a notational device for subscripted
  3071 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3072 expressions.  Secondly, in a local context with structure
  3073 declarations, number indexes \<^sub>n or the empty index (default
  3074 number 1) refer to a certain fixed variable implicitly; option
  3075 show_structs controls printing of implicit structures.  Typical
  3076 applications of these concepts involve record types and locales.
  3077 
  3078 * New command 'no_syntax' removes grammar declarations (and
  3079 translations) resulting from the given syntax specification, which is
  3080 interpreted in the same manner as for the 'syntax' command.
  3081 
  3082 * 'Advanced' translation functions (parse_translation etc.) may depend
  3083 on the signature of the theory context being presently used for
  3084 parsing/printing, see also isar-ref manual.
  3085 
  3086 * Improved 'oracle' command provides a type-safe interface to turn an
  3087 ML expression of type theory -> T -> term into a primitive rule of
  3088 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3089 is already included here); see also FOL/ex/IffExample.thy;
  3090 INCOMPATIBILITY.
  3091 
  3092 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3093 before); "cI" is no longer bound, use "c.intro" instead.
  3094 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3095 axclasses vs. locales.
  3096 
  3097 * Improved internal renaming of symbolic identifiers -- attach primes
  3098 instead of base 26 numbers.
  3099 
  3100 * New flag show_question_marks controls printing of leading question
  3101 marks in schematic variable names.
  3102 
  3103 * In schematic variable names, *any* symbol following \<^isub> or
  3104 \<^isup> is now treated as part of the base name.  For example, the
  3105 following works without printing of awkward ".0" indexes:
  3106 
  3107   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3108     by simp
  3109 
  3110 * Inner syntax includes (*(*nested*) comments*).
  3111 
  3112 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3113 annotations as "(00...)".
  3114 
  3115 * Clear separation of logical types and nonterminals, where the latter
  3116 may only occur in 'syntax' specifications or type abbreviations.
  3117 Before that distinction was only partially implemented via type class
  3118 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3119 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3120 exotic syntax specifications may require further adaption
  3121 (e.g. Cube/Cube.thy).
  3122 
  3123 * Removed obsolete type class "logic", use the top sort {} instead.
  3124 Note that non-logical types should be declared as 'nonterminals'
  3125 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3126 specifications.
  3127 
  3128 * Attributes 'induct' and 'cases': type or set names may now be
  3129 locally fixed variables as well.
  3130 
  3131 * Simplifier: can now control the depth to which conditional rewriting
  3132 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3133 Limit.
  3134 
  3135 * Simplifier: simplification procedures may now take the current
  3136 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3137 interface), which is very useful for calling the Simplifier
  3138 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3139 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3140 low-level mk_simproc no longer applies Logic.varify internally, to
  3141 allow for use in a context of fixed variables.
  3142 
  3143 * thin_tac now works even if the assumption being deleted contains !!
  3144 or ==>.  More generally, erule now works even if the major premise of
  3145 the elimination rule contains !! or ==>.
  3146 
  3147 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3148 
  3149 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3150 from Pure, which contains all common declarations already.  Both
  3151 theories are defined via plain Isabelle/Isar .thy files.
  3152 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3153 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3154 use isatool fixcpure to adapt your theory and ML sources.
  3155 
  3156 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3157 selections of theorems in named facts via index ranges.
  3158 
  3159 * 'print_theorems': in theory mode, really print the difference
  3160 wrt. the last state (works for interactive theory development only),
  3161 in proof mode print all local facts (cf. 'print_facts');
  3162 
  3163 * 'hide': option '(open)' hides only base names.
  3164 
  3165 * More efficient treatment of intermediate checkpoints in interactive
  3166 theory development.
  3167 
  3168 * Code generator is now invoked via code_module (incremental code
  3169 generation) and code_library (modular code generation, ML structures
  3170 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3171 must be quoted when used as identifiers.
  3172 
  3173 * New 'value' command for reading, evaluating and printing terms using
  3174 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3175 quoted when used as identifier.
  3176 
  3177 
  3178 *** Locales ***
  3179 
  3180 * New commands for the interpretation of locale expressions in
  3181 theories (1), locales (2) and proof contexts (3).  These generate
  3182 proof obligations from the expression specification.  After the
  3183 obligations have been discharged, theorems of the expression are added
  3184 to the theory, target locale or proof context.  The synopsis of the
  3185 commands is a follows:
  3186 
  3187   (1) interpretation expr inst
  3188   (2) interpretation target < expr
  3189   (3) interpret expr inst
  3190 
  3191 Interpretation in theories and proof contexts require a parameter
  3192 instantiation of terms from the current context.  This is applied to
  3193 specifications and theorems of the interpreted expression.
  3194 Interpretation in locales only permits parameter renaming through the
  3195 locale expression.  Interpretation is smart in that interpretations
  3196 that are active already do not occur in proof obligations, neither are
  3197 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3198 inspect active interpretations of a particular locale.  For details,
  3199 see the Isar Reference manual.  Examples can be found in
  3200 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3201 
  3202 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3203 'interpret' instead.
  3204 
  3205 * New context element 'constrains' for adding type constraints to
  3206 parameters.
  3207 
  3208 * Context expressions: renaming of parameters with syntax
  3209 redeclaration.
  3210 
  3211 * Locale declaration: 'includes' disallowed.
  3212 
  3213 * Proper static binding of attribute syntax -- i.e. types / terms /
  3214 facts mentioned as arguments are always those of the locale definition
  3215 context, independently of the context of later invocations.  Moreover,
  3216 locale operations (renaming and type / term instantiation) are applied
  3217 to attribute arguments as expected.
  3218 
  3219 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3220 actual attributes; rare situations may require Attrib.attribute to
  3221 embed those attributes into Attrib.src that lack concrete syntax.
  3222 Attribute implementations need to cooperate properly with the static
  3223 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3224 Attrib.XXX_thm etc. already do the right thing without further
  3225 intervention.  Only unusual applications -- such as "where" or "of"
  3226 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3227 on the context and the facts involved -- may have to assign parsed
  3228 values to argument tokens explicitly.
  3229 
  3230 * Changed parameter management in theorem generation for long goal
  3231 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3232 theorem statement in rare situations.
  3233 
  3234 * Locale inspection command 'print_locale' omits notes elements.  Use
  3235 'print_locale!' to have them included in the output.
  3236 
  3237 
  3238 *** Provers ***
  3239 
  3240 * Provers/hypsubst.ML: improved version of the subst method, for
  3241 single-step rewriting: it now works in bound variable contexts. New is
  3242 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3243 rewrite a different subterm than the original subst method, which is
  3244 still available as 'simplesubst'.
  3245 
  3246 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3247 and quasi orders.
  3248 
  3249 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3250 reflexive-transitive closure of relations.
  3251 
  3252 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3253 limit (previously hard-coded with a value of 20) user-definable.
  3254 
  3255 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3256 is peformed already.  Object-logics merely need to finish their
  3257 initial simpset configuration as before.  INCOMPATIBILITY.
  3258 
  3259 
  3260 *** HOL ***
  3261 
  3262 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3263 
  3264   syntax (epsilon)
  3265     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3266 
  3267 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3268 and x-symbol; use option '-m epsilon' to get it actually printed.
  3269 Moreover, the mathematically important symbolic identifier \<epsilon>
  3270 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3271 
  3272 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3273 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3274 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3275 support corresponding Isar calculations.
  3276 
  3277 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3278 instead of ":".
  3279 
  3280 * theory SetInterval: changed the syntax for open intervals:
  3281 
  3282   Old       New
  3283   {..n(}    {..<n}
  3284   {)n..}    {n<..}
  3285   {m..n(}   {m..<n}
  3286   {)m..n}   {m<..n}
  3287   {)m..n(}  {m<..<n}
  3288 
  3289 The old syntax is still supported but will disappear in the next
  3290 release.  For conversion use the following Emacs search and replace
  3291 patterns (these are not perfect but work quite well):
  3292 
  3293   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3294   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3295 
  3296 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3297 equalities in commutative rings; method 'algebra' provides a generic
  3298 interface.
  3299 
  3300 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3301 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3302 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3303 be a tuple pattern.
  3304 
  3305 Some new syntax forms are available:
  3306 
  3307   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3308   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3309   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3310   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3311 
  3312 The latter form "\<Sum>x < k. e" used to be based on a separate
  3313 function "Summation", which has been discontinued.
  3314 
  3315 * theory Finite_Set: in structured induction proofs, the insert case
  3316 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3317 (insert F x)'.
  3318 
  3319 * The 'refute' command has been extended to support a much larger
  3320 fragment of HOL, including axiomatic type classes, constdefs and
  3321 typedefs, inductive datatypes and recursion.
  3322 
  3323 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3324 Requires zChaff with proof generation to be installed.  See
  3325 HOL/ex/SAT_Examples.thy for examples.
  3326 
  3327 * Datatype induction via method 'induct' now preserves the name of the
  3328 induction variable. For example, when proving P(xs::'a list) by
  3329 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3330 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3331 in unstructured proof scripts.
  3332 
  3333 * Reworked implementation of records.  Improved scalability for
  3334 records with many fields, avoiding performance problems for type
  3335 inference. Records are no longer composed of nested field types, but
  3336 of nested extension types. Therefore the record type only grows linear
  3337 in the number of extensions and not in the number of fields.  The
  3338 top-level (users) view on records is preserved.  Potential
  3339 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3340 old record representation. The type generated for a record is called
  3341 <record_name>_ext_type.
  3342 
  3343 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3344 proofs triggered by a record definition or a simproc (if
  3345 quick_and_dirty is enabled).  Definitions of large records can take
  3346 quite long.
  3347 
  3348 New simproc record_upd_simproc for simplification of multiple record
  3349 updates enabled by default.  Moreover, trivial updates are also
  3350 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3351 occasionally, since simplification is more powerful by default.
  3352 
  3353 * typedef: proper support for polymorphic sets, which contain extra
  3354 type-variables in the term.
  3355 
  3356 * Simplifier: automatically reasons about transitivity chains
  3357 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3358 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3359 old proofs break occasionally as simplification may now solve more
  3360 goals than previously.
  3361 
  3362 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3363 present.  Works for all partial orders (class "order"), in particular
  3364 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3365 just like y <= x.
  3366 
  3367 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3368 bound variable or a constant then the let is unfolded.  Otherwise
  3369 first a is simplified to b, and then f b is simplified to g. If
  3370 possible we abstract b from g arriving at "let x = b in h x",
  3371 otherwise we unfold the let and arrive at g.  The simproc can be
  3372 enabled/disabled by the reference use_let_simproc.  Potential
  3373 INCOMPATIBILITY since simplification is more powerful by default.
  3374 
  3375 * Classical reasoning: the meson method now accepts theorems as arguments.
  3376 
  3377 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3378 jobs to provide advice on the provability of subgoals.
  3379 
  3380 * Theory OrderedGroup and Ring_and_Field: various additions and
  3381 improvements to faciliate calculations involving equalities and
  3382 inequalities.
  3383 
  3384 The following theorems have been eliminated or modified
  3385 (INCOMPATIBILITY):
  3386 
  3387   abs_eq             now named abs_of_nonneg
  3388   abs_of_ge_0        now named abs_of_nonneg
  3389   abs_minus_eq       now named abs_of_nonpos
  3390   imp_abs_id         now named abs_of_nonneg
  3391   imp_abs_neg_id     now named abs_of_nonpos
  3392   mult_pos           now named mult_pos_pos
  3393   mult_pos_le        now named mult_nonneg_nonneg
  3394   mult_pos_neg_le    now named mult_nonneg_nonpos
  3395   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3396   mult_neg           now named mult_neg_neg
  3397   mult_neg_le        now named mult_nonpos_nonpos
  3398 
  3399 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3400      
  3401      zero_le_square
  3402      not_square_less_zero 
  3403 
  3404   The following lemmas have been deleted from Real/RealPow:
  3405   
  3406      realpow_zero_zero
  3407      realpow_two
  3408      realpow_less
  3409      zero_le_power
  3410      realpow_two_le
  3411      abs_realpow_two
  3412      realpow_two_abs     
  3413 
  3414 * Theory Parity: added rules for simplifying exponents.
  3415 
  3416 * Theory List:
  3417 
  3418 The following theorems have been eliminated or modified
  3419 (INCOMPATIBILITY):
  3420 
  3421   list_all_Nil       now named list_all.simps(1)
  3422   list_all_Cons      now named list_all.simps(2)
  3423   list_all_conv      now named list_all_iff
  3424   set_mem_eq         now named mem_iff
  3425 
  3426 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3427 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3428 
  3429 
  3430 *** HOL-Complex ***
  3431 
  3432 * Theory RealDef: better support for embedding natural numbers and
  3433 integers in the reals.
  3434 
  3435 The following theorems have been eliminated or modified
  3436 (INCOMPATIBILITY):
  3437 
  3438   exp_ge_add_one_self  now requires no hypotheses
  3439   real_of_int_add      reversed direction of equality (use [symmetric])
  3440   real_of_int_minus    reversed direction of equality (use [symmetric])
  3441   real_of_int_diff     reversed direction of equality (use [symmetric])
  3442   real_of_int_mult     reversed direction of equality (use [symmetric])
  3443 
  3444 * Theory RComplete: expanded support for floor and ceiling functions.
  3445 
  3446 * Theory Ln is new, with properties of the natural logarithm
  3447 
  3448 * Hyperreal: There is a new type constructor "star" for making
  3449 nonstandard types.  The old type names are now type synonyms:
  3450 
  3451   hypreal = real star
  3452   hypnat = nat star
  3453   hcomplex = complex star
  3454 
  3455 * Hyperreal: Many groups of similarly-defined constants have been
  3456 replaced by polymorphic versions (INCOMPATIBILITY):
  3457 
  3458   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3459 
  3460   starset      <-- starsetNat, starsetC
  3461   *s*          <-- *sNat*, *sc*
  3462   starset_n    <-- starsetNat_n, starsetC_n
  3463   *sn*         <-- *sNatn*, *scn*
  3464   InternalSets <-- InternalNatSets, InternalCSets
  3465 
  3466   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3467   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3468   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3469   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3470   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3471 
  3472 * Hyperreal: Many type-specific theorems have been removed in favor of
  3473 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3474 
  3475   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3476   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3477   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3478   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3479   right_minus <-- hypreal_add_minus
  3480   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3481   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3482   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3483   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3484   mult_1_right <-- hcomplex_mult_one_right
  3485   mult_zero_left <-- hcomplex_mult_zero_left
  3486   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3487   right_distrib <-- hypnat_add_mult_distrib2
  3488   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3489   right_inverse <-- hypreal_mult_inverse
  3490   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3491   order_refl <-- {hypreal,hypnat}_le_refl
  3492   order_trans <-- {hypreal,hypnat}_le_trans
  3493   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3494   order_less_le <-- {hypreal,hypnat}_less_le
  3495   linorder_linear <-- {hypreal,hypnat}_le_linear
  3496   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3497   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3498   add_nonneg_nonneg <-- hypreal_le_add_order
  3499 
  3500 * Hyperreal: Separate theorems having to do with type-specific
  3501 versions of constants have been merged into theorems that apply to the
  3502 new polymorphic constants (INCOMPATIBILITY):
  3503 
  3504   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3505   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3506   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3507   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3508   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3509   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3510   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3511   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3512   STAR_diff <-- {STAR,STARC}_diff
  3513   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3514     STARC_hcomplex_of_complex}_image_subset
  3515   starset_n_Un <-- starset{Nat,C}_n_Un
  3516   starset_n_Int <-- starset{Nat,C}_n_Int
  3517   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3518   starset_n_diff <-- starset{Nat,C}_n_diff
  3519   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3520   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3521   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3522   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3523   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3524   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3525   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3526   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3527   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3528   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3529   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3530   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3531   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3532   starfun_diff <-- starfun{C,RC,CR}_diff
  3533   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3534   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3535   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3536   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3537   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3538   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3539   starfun_Id <-- starfunC_Id
  3540   starfun_approx <-- starfun{Nat,CR}_approx
  3541   starfun_capprox <-- starfun{C,RC}_capprox
  3542   starfun_abs <-- starfunNat_rabs
  3543   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3544   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3545   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3546   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3547   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3548   starfun_add_approx <-- starfunCR_add_approx
  3549   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3550   starfun_divide <-- starfun{C,CR,RC}_divide
  3551   starfun_n <-- starfun{Nat,C}_n
  3552   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3553   starfun_n_add <-- starfun{Nat,C}_n_add
  3554   starfun_n_add_minus <-- starfunNat_n_add_minus
  3555   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3556   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3557   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3558 
  3559   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3560   star_n_minus <-- {hypreal,hcomplex}_minus
  3561   star_n_diff <-- {hypreal,hcomplex}_diff
  3562   star_n_mult <-- {hypreal,hcomplex}_mult
  3563   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3564   star_n_le <-- {hypreal,hypnat}_le
  3565   star_n_less <-- {hypreal,hypnat}_less
  3566   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3567   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3568   star_n_abs <-- hypreal_hrabs
  3569   star_n_divide <-- hcomplex_divide
  3570 
  3571   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3572   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3573   star_of_diff <-- hypreal_of_real_diff
  3574   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3575   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3576   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3577   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3578   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3579   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3580   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3581   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3582   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3583   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3584   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3585   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3586   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3587   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3588   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3589   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3590   star_of_power <-- hypreal_of_real_power
  3591   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3592 
  3593 * Hyperreal: new method "transfer" that implements the transfer
  3594 principle of nonstandard analysis. With a subgoal that mentions
  3595 nonstandard types like "'a star", the command "apply transfer"
  3596 replaces it with an equivalent one that mentions only standard types.
  3597 To be successful, all free variables must have standard types; non-
  3598 standard variables must have explicit universal quantifiers.
  3599 
  3600 * Hyperreal: A theory of Taylor series.
  3601 
  3602 
  3603 *** HOLCF ***
  3604 
  3605 * Discontinued special version of 'constdefs' (which used to support
  3606 continuous functions) in favor of the general Pure one with full
  3607 type-inference.
  3608 
  3609 * New simplification procedure for solving continuity conditions; it
  3610 is much faster on terms with many nested lambda abstractions (cubic
  3611 instead of exponential time).
  3612 
  3613 * New syntax for domain package: selector names are now optional.
  3614 Parentheses should be omitted unless argument is lazy, for example:
  3615 
  3616   domain 'a stream = cons "'a" (lazy "'a stream")
  3617 
  3618 * New command 'fixrec' for defining recursive functions with pattern
  3619 matching; defining multiple functions with mutual recursion is also
  3620 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3621 sinr, or any data constructor defined by the domain package. The given
  3622 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3623 syntax and examples.
  3624 
  3625 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3626 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3627 but the proof obligation additionally includes an admissibility
  3628 requirement. The packages generate instances of class cpo or pcpo,
  3629 with continuity and strictness theorems for Rep and Abs.
  3630 
  3631 * HOLCF: Many theorems have been renamed according to a more standard naming
  3632 scheme (INCOMPATIBILITY):
  3633 
  3634   foo_inject:  "foo$x = foo$y ==> x = y"
  3635   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3636   foo_less:    "(foo$x << foo$y) = (x << y)"
  3637   foo_strict:  "foo$UU = UU"
  3638   foo_defined: "... ==> foo$x ~= UU"
  3639   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3640 
  3641 
  3642 *** ZF ***
  3643 
  3644 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3645 including the First Isomorphism Theorem (on quotienting by the kernel
  3646 of a homomorphism).
  3647 
  3648 * ZF/Simplifier: install second copy of type solver that actually
  3649 makes use of TC rules declared to Isar proof contexts (or locales);
  3650 the old version is still required for ML proof scripts.
  3651 
  3652 
  3653 *** Cube ***
  3654 
  3655 * Converted to Isar theory format; use locales instead of axiomatic
  3656 theories.
  3657 
  3658 
  3659 *** ML ***
  3660 
  3661 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3662 for ||>, ||>>, |>>,
  3663 
  3664 * Pure/library.ML no longer defines its own option datatype, but uses
  3665 that of the SML basis, which has constructors NONE and SOME instead of
  3666 None and Some, as well as exception Option.Option instead of OPTION.
  3667 The functions the, if_none, is_some, is_none have been adapted
  3668 accordingly, while Option.map replaces apsome.
  3669 
  3670 * Pure/library.ML: the exception LIST has been given up in favour of
  3671 the standard exceptions Empty and Subscript, as well as
  3672 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3673 superceded by the standard hd and tl functions etc.
  3674 
  3675 A number of basic list functions are no longer exported to the ML
  3676 toplevel, as they are variants of predefined functions.  The following
  3677 suggests how one can translate existing code:
  3678 
  3679     rev_append xs ys = List.revAppend (xs, ys)
  3680     nth_elem (i, xs) = List.nth (xs, i)
  3681     last_elem xs = List.last xs
  3682     flat xss = List.concat xss
  3683     seq fs = List.app fs
  3684     partition P xs = List.partition P xs
  3685     mapfilter f xs = List.mapPartial f xs
  3686 
  3687 * Pure/library.ML: several combinators for linear functional
  3688 transformations, notably reverse application and composition:
  3689 
  3690   x |> f                f #> g
  3691   (x, y) |-> f          f #-> g
  3692 
  3693 * Pure/library.ML: introduced/changed precedence of infix operators:
  3694 
  3695   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3696   infix 2 ?;
  3697   infix 3 o oo ooo oooo;
  3698   infix 4 ~~ upto downto;
  3699 
  3700 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3701 infix operators.
  3702 
  3703 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3704 fold_map support linear functional transformations and nesting.  For
  3705 example:
  3706 
  3707   fold f [x1, ..., xN] y =
  3708     y |> f x1 |> ... |> f xN
  3709 
  3710   (fold o fold) f [xs1, ..., xsN] y =
  3711     y |> fold f xs1 |> ... |> fold f xsN
  3712 
  3713   fold f [x1, ..., xN] =
  3714     f x1 #> ... #> f xN
  3715 
  3716   (fold o fold) f [xs1, ..., xsN] =
  3717     fold f xs1 #> ... #> fold f xsN
  3718 
  3719 * Pure/library.ML: the following selectors on type 'a option are
  3720 available:
  3721 
  3722   the:               'a option -> 'a  (*partial*)
  3723   these:             'a option -> 'a  where 'a = 'b list
  3724   the_default: 'a -> 'a option -> 'a
  3725   the_list:          'a option -> 'a list
  3726 
  3727 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3728 basic operations for association lists, following natural argument
  3729 order; moreover the explicit equality predicate passed here avoids
  3730 potentially expensive polymorphic runtime equality checks.
  3731 The old functions may be expressed as follows:
  3732 
  3733   assoc = uncurry (AList.lookup (op =))
  3734   assocs = these oo AList.lookup (op =)
  3735   overwrite = uncurry (AList.update (op =)) o swap
  3736 
  3737 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3738 
  3739   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3740   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3741 
  3742 replacing make_keylist and keyfilter (occassionally used)
  3743 Naive rewrites:
  3744 
  3745   make_keylist = AList.make
  3746   keyfilter = AList.find (op =)
  3747 
  3748 * eq_fst and eq_snd now take explicit equality parameter, thus
  3749   avoiding eqtypes. Naive rewrites:
  3750 
  3751     eq_fst = eq_fst (op =)
  3752     eq_snd = eq_snd (op =)
  3753 
  3754 * Removed deprecated apl and apr (rarely used).
  3755   Naive rewrites:
  3756 
  3757     apl (n, op) =>>= curry op n
  3758     apr (op, m) =>>= fn n => op (n, m)
  3759 
  3760 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3761 provides a reasonably efficient light-weight implementation of sets as
  3762 lists.
  3763 
  3764 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3765 few new operations; existing lookup and update are now curried to
  3766 follow natural argument order (for use with fold etc.);
  3767 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3768 
  3769 * Pure/General: output via the Isabelle channels of
  3770 writeln/warning/error etc. is now passed through Output.output, with a
  3771 hook for arbitrary transformations depending on the print_mode
  3772 (cf. Output.add_mode -- the first active mode that provides a output
  3773 function wins).  Already formatted output may be embedded into further
  3774 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3775 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3776 accommodate easy composition of diagnostic messages etc.  Programmers
  3777 rarely need to care about Output.output or Output.raw at all, with
  3778 some notable exceptions: Output.output is required when bypassing the
  3779 standard channels (writeln etc.), or in token translations to produce
  3780 properly formatted results; Output.raw is required when capturing
  3781 already output material that will eventually be presented to the user
  3782 a second time.  For the default print mode, both Output.output and
  3783 Output.raw have no effect.
  3784 
  3785 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3786 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3787 cumulative results are displayed at the end of a batch session.
  3788 
  3789 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3790 replaced by File.platform_path and File.shell_path (with appropriate
  3791 hooks).  This provides a clean interface for unusual systems where the
  3792 internal and external process view of file names are different.
  3793 
  3794 * Pure: more efficient orders for basic syntactic entities: added
  3795 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3796 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3797 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3798 orders now -- potential INCOMPATIBILITY for code that depends on a
  3799 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3800 Library.sort_strings on result).
  3801 
  3802 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3803 fold_types traverse types/terms from left to right, observing natural
  3804 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3805 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3806 
  3807 * Pure: name spaces have been refined, with significant changes of the
  3808 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3809 to extern(_table).  The plain name entry path is superceded by a
  3810 general 'naming' context, which also includes the 'policy' to produce
  3811 a fully qualified name and external accesses of a fully qualified
  3812 name; NameSpace.extend is superceded by context dependent
  3813 Sign.declare_name.  Several theory and proof context operations modify
  3814 the naming context.  Especially note Theory.restore_naming and
  3815 ProofContext.restore_naming to get back to a sane state; note that
  3816 Theory.add_path is no longer sufficient to recover from
  3817 Theory.absolute_path in particular.
  3818 
  3819 * Pure: new flags short_names (default false) and unique_names
  3820 (default true) for controlling output of qualified names.  If
  3821 short_names is set, names are printed unqualified.  If unique_names is
  3822 reset, the name prefix is reduced to the minimum required to achieve
  3823 the original result when interning again, even if there is an overlap
  3824 with earlier declarations.
  3825 
  3826 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3827 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3828 (useful for printing error messages).  INCOMPATIBILITY.
  3829 
  3830 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3831 Theory.theory are now identified, referring to the universal
  3832 Context.theory (see Pure/context.ML).  Actual signature and theory
  3833 content is managed as theory data.  The old code and interfaces were
  3834 spread over many files and structures; the new arrangement introduces
  3835 considerable INCOMPATIBILITY to gain more clarity:
  3836 
  3837   Context -- theory management operations (name, identity, inclusion,
  3838     parents, ancestors, merge, etc.), plus generic theory data;
  3839 
  3840   Sign -- logical signature and syntax operations (declaring consts,
  3841     types, etc.), plus certify/read for common entities;
  3842 
  3843   Theory -- logical theory operations (stating axioms, definitions,
  3844     oracles), plus a copy of logical signature operations (consts,
  3845     types, etc.); also a few basic management operations (Theory.copy,
  3846     Theory.merge, etc.)
  3847 
  3848 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3849 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3850 for convenience -- they merely return the theory.
  3851 
  3852 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3853 
  3854 * Pure: the Isar proof context type is already defined early in Pure
  3855 as Context.proof (note that ProofContext.context and Proof.context are
  3856 aliases, where the latter is the preferred name).  This enables other
  3857 Isabelle components to refer to that type even before Isar is present.
  3858 
  3859 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3860 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3861 any of these kinds.  For example, Sign.intern typeK is now
  3862 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3863 Theory.hide_types.  Also note that former
  3864 Theory.hide_classes/types/consts are now
  3865 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3866 internalize their arguments!  INCOMPATIBILITY.
  3867 
  3868 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3869 datatype thmref (with constructors Name and NameSelection) instead of
  3870 plain string -- INCOMPATIBILITY;
  3871 
  3872 * Pure: cases produced by proof methods specify options, where NONE
  3873 means to remove case bindings -- INCOMPATIBILITY in
  3874 (RAW_)METHOD_CASES.
  3875 
  3876 * Pure: the following operations retrieve axioms or theorems from a
  3877 theory node or theory hierarchy, respectively:
  3878 
  3879   Theory.axioms_of: theory -> (string * term) list
  3880   Theory.all_axioms_of: theory -> (string * term) list
  3881   PureThy.thms_of: theory -> (string * thm) list
  3882   PureThy.all_thms_of: theory -> (string * thm) list
  3883 
  3884 * Pure: print_tac now outputs the goal through the trace channel.
  3885 
  3886 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3887 Reference Toplevel.debug (default false) controls detailed printing
  3888 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3889 controls execution profiling -- set to 1 for time and 2 for space
  3890 (both increase the runtime).
  3891 
  3892 * Isar session: The initial use of ROOT.ML is now always timed,
  3893 i.e. the log will show the actual process times, in contrast to the
  3894 elapsed wall-clock time that the outer shell wrapper produces.
  3895 
  3896 * Simplifier: improved handling of bound variables (nameless
  3897 representation, avoid allocating new strings).  Simprocs that invoke
  3898 the Simplifier recursively should use Simplifier.inherit_bounds to
  3899 avoid local name clashes.  Failure to do so produces warnings
  3900 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3901 for further details.
  3902 
  3903 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3904 bindings for all theorems stored within a given theory; this may help
  3905 in porting non-Isar theories to Isar ones, while keeping ML proof
  3906 scripts for the time being.
  3907 
  3908 * ML operator HTML.with_charset specifies the charset begin used for
  3909 generated HTML files.  For example:
  3910 
  3911   HTML.with_charset "utf-8" use_thy "Hebrew";
  3912   HTML.with_charset "utf-8" use_thy "Chinese";
  3913 
  3914 
  3915 *** System ***
  3916 
  3917 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3918 isabelle, isatool etc.).
  3919 
  3920 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3921 isatool doc, isatool mkdir, display_drafts etc.).
  3922 
  3923 * isatool usedir: option -f allows specification of the ML file to be
  3924 used by Isabelle; default is ROOT.ML.
  3925 
  3926 * New isatool version outputs the version identifier of the Isabelle
  3927 distribution being used.
  3928 
  3929 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3930 (containing Boolean satisfiability problems) into Isabelle/HOL
  3931 theories.
  3932 
  3933 
  3934 
  3935 New in Isabelle2004 (April 2004)
  3936 --------------------------------
  3937 
  3938 *** General ***
  3939 
  3940 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3941   Replaces linorder.ML.
  3942 
  3943 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3944   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3945   (\<a>...\<z>), are now considered normal letters, and can therefore
  3946   be used anywhere where an ASCII letter (a...zA...Z) has until
  3947   now. COMPATIBILITY: This obviously changes the parsing of some
  3948   terms, especially where a symbol has been used as a binder, say
  3949   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3950   as an identifier.  Fix it by inserting a space around former
  3951   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3952   existing theory and ML files.
  3953 
  3954 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3955 
  3956 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3957   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3958   a normal (but invisible) letter. For multiple letter subscripts repeat
  3959   \<^isub> like this: x\<^isub>1\<^isub>2.
  3960 
  3961 * Pure: There are now sub-/superscripts that can span more than one
  3962   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3963   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3964   superscript. The new control characters are not identifier parts.
  3965 
  3966 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3967   content of "..." to the latex file instead of \isacntrl... . The "..."
  3968   may consist of any printable characters excluding the end bracket >.
  3969 
  3970 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3971   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3972   declare constants "final", which prevents their being given a definition
  3973   later.  It is useful for constants whose behaviour is fixed axiomatically
  3974   rather than definitionally, such as the meta-logic connectives.
  3975 
  3976 * Pure: 'instance' now handles general arities with general sorts
  3977   (i.e. intersections of classes),
  3978 
  3979 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3980   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3981   It can be changed to alter the colors/layout of generated pages.
  3982 
  3983 
  3984 *** Isar ***
  3985 
  3986 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3987   cut_tac, subgoal_tac and thin_tac:
  3988   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3989     locales are no longer forced to write Isar proof scripts.
  3990     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3991     emulations.
  3992   - INCOMPATIBILITY: names of variables to be instantiated may no
  3993     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3994     This is consistent with the instantiation attribute "where".
  3995 
  3996 * Attributes "where" and "of":
  3997   - Now take type variables of instantiated theorem into account when reading
  3998     the instantiation string.  This fixes a bug that caused instantiated
  3999     theorems to have too special types in some circumstances.
  4000   - "where" permits explicit instantiations of type variables.
  4001 
  4002 * Calculation commands "moreover" and "also" no longer interfere with
  4003   current facts ("this"), admitting arbitrary combinations with "then"
  4004   and derived forms.
  4005 
  4006 * Locales:
  4007   - Goal statements involving the context element "includes" no longer
  4008     generate theorems with internal delta predicates (those ending on
  4009     "_axioms") in the premise.
  4010     Resolve particular premise with <locale>.intro to obtain old form.
  4011   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4012     specification and "includes" elements in goal statement.
  4013   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4014     [intro?] and [elim?] (respectively) by default.
  4015   - Experimental command for instantiation of locales in proof contexts:
  4016         instantiate <label>[<attrs>]: <loc>
  4017     Instantiates locale <loc> and adds all its theorems to the current context
  4018     taking into account their attributes.  Label and attrs are optional
  4019     modifiers, like in theorem declarations.  If present, names of
  4020     instantiated theorems are qualified with <label>, and the attributes
  4021     <attrs> are applied after any attributes these theorems might have already.
  4022       If the locale has assumptions, a chained fact of the form
  4023     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4024     are derived.  The command does not support old-style locales declared
  4025     with "locale (open)".
  4026       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4027 
  4028 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4029   (Isar) contexts.
  4030 
  4031 
  4032 *** HOL ***
  4033 
  4034 * Proof import: new image HOL4 contains the imported library from
  4035   the HOL4 system with about 2500 theorems. It is imported by
  4036   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4037   can be used like any other Isabelle image.  See
  4038   HOL/Import/HOL/README for more information.
  4039 
  4040 * Simplifier:
  4041   - Much improved handling of linear and partial orders.
  4042     Reasoners for linear and partial orders are set up for type classes
  4043     "linorder" and "order" respectively, and are added to the default simpset
  4044     as solvers.  This means that the simplifier can build transitivity chains
  4045     to solve goals from the assumptions.
  4046   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4047     of blast or auto after simplification become unnecessary because the goal
  4048     is solved by simplification already.
  4049 
  4050 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4051     all proved in axiomatic type classes for semirings, rings and fields.
  4052 
  4053 * Numerics:
  4054   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4055     now formalized using the Ring_and_Field theory mentioned above.
  4056   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4057     than before, because now they are set up once in a generic manner.
  4058   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4059     Look for the general versions in Ring_and_Field (and Power if they concern
  4060     exponentiation).
  4061 
  4062 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4063 
  4064 * Records:
  4065   - Record types are now by default printed with their type abbreviation
  4066     instead of the list of all field types. This can be configured via
  4067     the reference "print_record_type_abbr".
  4068   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4069     (not enabled by default).
  4070   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4071     EX x. x = sel r to True (not enabled by default).
  4072   - Tactic "record_split_simp_tac" to split and simplify records added.
  4073 
  4074 * 'specification' command added, allowing for definition by
  4075   specification.  There is also an 'ax_specification' command that
  4076   introduces the new constants axiomatically.
  4077 
  4078 * arith(_tac) is now able to generate counterexamples for reals as well.
  4079 
  4080 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4081 
  4082 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4083   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4084 
  4085 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4086   matrix theory to linear programming.
  4087 
  4088 * Unions and Intersections:
  4089   The latex output syntax of UN and INT has been changed
  4090   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4091   i.e. the index formulae has become a subscript.
  4092   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4093 
  4094 * Unions and Intersections over Intervals:
  4095   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4096   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4097   like in normal math, and corresponding versions for < and for intersection.
  4098 
  4099 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4100   lexicographic dictonary ordering has been added as "lexord".
  4101 
  4102 * ML: the legacy theory structures Int and List have been removed. They had
  4103   conflicted with ML Basis Library structures having the same names.
  4104 
  4105 * 'refute' command added to search for (finite) countermodels.  Only works
  4106   for a fragment of HOL.  The installation of an external SAT solver is
  4107   highly recommended.  See "HOL/Refute.thy" for details.
  4108 
  4109 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4110   formulae under an assignment of free variables to random values.
  4111   In contrast to 'refute', it can deal with inductive datatypes,
  4112   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4113   for examples.
  4114 
  4115 
  4116 *** HOLCF ***
  4117 
  4118 * Streams now come with concatenation and are part of the HOLCF image
  4119 
  4120 
  4121 
  4122 New in Isabelle2003 (May 2003)
  4123 ------------------------------
  4124 
  4125 *** General ***
  4126 
  4127 * Provers/simplifier:
  4128 
  4129   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4130     Assumptions are now subject to complete mutual simplification,
  4131     not just from left to right. The simplifier now preserves
  4132     the order of assumptions.
  4133 
  4134     Potential INCOMPATIBILITY:
  4135 
  4136     -- simp sometimes diverges where the old version did
  4137        not, e.g. invoking simp on the goal
  4138 
  4139         [| P (f x); y = x; f x = f y |] ==> Q
  4140 
  4141        now gives rise to the infinite reduction sequence
  4142 
  4143         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4144 
  4145        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4146        kind of problem.
  4147 
  4148     -- Tactics combining classical reasoner and simplification (such as auto)
  4149        are also affected by this change, because many of them rely on
  4150        simp. They may sometimes diverge as well or yield a different numbers
  4151        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4152        in case of problems. Sometimes subsequent calls to the classical
  4153        reasoner will fail because a preceeding call to the simplifier too
  4154        eagerly simplified the goal, e.g. deleted redundant premises.
  4155 
  4156   - The simplifier trace now shows the names of the applied rewrite rules
  4157 
  4158   - You can limit the number of recursive invocations of the simplifier
  4159     during conditional rewriting (where the simplifie tries to solve the
  4160     conditions before applying the rewrite rule):
  4161     ML "simp_depth_limit := n"
  4162     where n is an integer. Thus you can force termination where previously
  4163     the simplifier would diverge.
  4164 
  4165   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4166 
  4167   - No longer aborts on failed congruence proof.  Instead, the
  4168     congruence is ignored.
  4169 
  4170 * Pure: New generic framework for extracting programs from constructive
  4171   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4172   as HOL/Extraction for some case studies.
  4173 
  4174 * Pure: The main goal of the proof state is no longer shown by default, only
  4175 the subgoals. This behaviour is controlled by a new flag.
  4176    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4177 (ML: Proof.show_main_goal).
  4178 
  4179 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4180 rules whose conclusion matches subgoal 1:
  4181       PG menu: Isabelle/Isar -> Show me -> matching rules
  4182 The rules are ordered by how closely they match the subgoal.
  4183 In particular, rules that solve a subgoal outright are displayed first
  4184 (or rather last, the way they are printed).
  4185 (ML: ProofGeneral.print_intros())
  4186 
  4187 * Pure: New flag trace_unify_fail causes unification to print
  4188 diagnostic information (PG: in trace buffer) when it fails. This is
  4189 useful for figuring out why single step proofs like rule, erule or
  4190 assumption failed.
  4191 
  4192 * Pure: Locale specifications now produce predicate definitions
  4193 according to the body of text (covering assumptions modulo local
  4194 definitions); predicate "loc_axioms" covers newly introduced text,
  4195 while "loc" is cumulative wrt. all included locale expressions; the
  4196 latter view is presented only on export into the global theory
  4197 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4198 on the old view without predicates;
  4199 
  4200 * Pure: predefined locales "var" and "struct" are useful for sharing
  4201 parameters (as in CASL, for example); just specify something like
  4202 ``var x + var y + struct M'' as import;
  4203 
  4204 * Pure: improved thms_containing: proper indexing of facts instead of
  4205 raw theorems; check validity of results wrt. current name space;
  4206 include local facts of proof configuration (also covers active
  4207 locales), cover fixed variables in index; may use "_" in term
  4208 specification; an optional limit for the number of printed facts may
  4209 be given (the default is 40);
  4210 
  4211 * Pure: disallow duplicate fact bindings within new-style theory files
  4212 (batch-mode only);
  4213 
  4214 * Provers: improved induct method: assumptions introduced by case
  4215 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4216 the goal statement); "foo" still refers to all facts collectively;
  4217 
  4218 * Provers: the function blast.overloaded has been removed: all constants
  4219 are regarded as potentially overloaded, which improves robustness in exchange
  4220 for slight decrease in efficiency;
  4221 
  4222 * Provers/linorder: New generic prover for transitivity reasoning over
  4223 linear orders.  Note: this prover is not efficient!
  4224 
  4225 * Isar: preview of problems to finish 'show' now produce an error
  4226 rather than just a warning (in interactive mode);
  4227 
  4228 
  4229 *** HOL ***
  4230 
  4231 * arith(_tac)
  4232 
  4233  - Produces a counter example if it cannot prove a goal.
  4234    Note that the counter example may be spurious if the goal is not a formula
  4235    of quantifier-free linear arithmetic.
  4236    In ProofGeneral the counter example appears in the trace buffer.
  4237 
  4238  - Knows about div k and mod k where k is a numeral of type nat or int.
  4239 
  4240  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4241    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4242    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4243 
  4244 * simp's arithmetic capabilities have been enhanced a bit: it now
  4245 takes ~= in premises into account (by performing a case split);
  4246 
  4247 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4248 are distributed over a sum of terms;
  4249 
  4250 * New tactic "trans_tac" and method "trans" instantiate
  4251 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4252 "<=", "<" and "=").
  4253 
  4254 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4255 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4256 
  4257 * 'typedef' command has new option "open" to suppress the set
  4258 definition;
  4259 
  4260 * functions Min and Max on finite sets have been introduced (theory
  4261 Finite_Set);
  4262 
  4263 * attribute [symmetric] now works for relations as well; it turns
  4264 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4265 
  4266 * induct over a !!-quantified statement (say !!x1..xn):
  4267   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4268 
  4269 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4270 %x. None. Warning: empty_def now refers to the previously hidden definition
  4271 of the empty set.
  4272 
  4273 * Algebra: formalization of classical algebra.  Intended as base for
  4274 any algebraic development in Isabelle.  Currently covers group theory
  4275 (up to Sylow's theorem) and ring theory (Universal Property of
  4276 Univariate Polynomials).  Contributions welcome;
  4277 
  4278 * GroupTheory: deleted, since its material has been moved to Algebra;
  4279 
  4280 * Complex: new directory of the complex numbers with numeric constants,
  4281 nonstandard complex numbers, and some complex analysis, standard and
  4282 nonstandard (Jacques Fleuriot);
  4283 
  4284 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4285 
  4286 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4287 Fleuriot);
  4288 
  4289 * Real/HahnBanach: updated and adapted to locales;
  4290 
  4291 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4292 Gray and Kramer);
  4293 
  4294 * UNITY: added the Meier-Sanders theory of progress sets;
  4295 
  4296 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4297 as abstract algorithms, instantiated to the JVM;
  4298 
  4299 * Bali: Java source language formalization. Type system, operational
  4300 semantics, axiomatic semantics. Supported language features:
  4301 classes, interfaces, objects,virtual methods, static methods,
  4302 static/instance fields, arrays, access modifiers, definite
  4303 assignment, exceptions.
  4304 
  4305 
  4306 *** ZF ***
  4307 
  4308 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4309 universe, etc.);
  4310 
  4311 * Main ZF: virtually all theories converted to new-style format;
  4312 
  4313 
  4314 *** ML ***
  4315 
  4316 * Pure: Tactic.prove provides sane interface for internal proofs;
  4317 omits the infamous "standard" operation, so this is more appropriate
  4318 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4319 
  4320 * Pure: improved error reporting of simprocs;
  4321 
  4322 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4323 up simprocs;
  4324 
  4325 
  4326 *** Document preparation ***
  4327 
  4328 * uses \par instead of \\ for line breaks in theory text. This may
  4329 shift some page breaks in large documents. To get the old behaviour
  4330 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4331 
  4332 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4333 other packages
  4334 
  4335 * \<euro> now needs package babel/greek instead of marvosym (which
  4336 broke \Rightarrow)
  4337 
  4338 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4339 textcomp package)
  4340 
  4341 
  4342 
  4343 New in Isabelle2002 (March 2002)
  4344 --------------------------------
  4345 
  4346 *** Document preparation ***
  4347 
  4348 * greatly simplified document preparation setup, including more
  4349 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4350 instructive isatool mkdir; users should basically be able to get
  4351 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4352 users may run a separate document processing stage manually like this:
  4353 "isatool usedir -D output HOL Test && isatool document Test/output";
  4354 
  4355 * theory dependency graph may now be incorporated into documents;
  4356 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4357 with \includegraphics of LaTeX;
  4358 
  4359 * proper spacing of consecutive markup elements, especially text
  4360 blocks after section headings;
  4361 
  4362 * support bold style (for single symbols only), input syntax is like
  4363 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4364 
  4365 * \<bullet> is now output as bold \cdot by default, which looks much
  4366 better in printed text;
  4367 
  4368 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4369 note that these symbols are currently unavailable in Proof General /
  4370 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4371 
  4372 * isatool latex no longer depends on changed TEXINPUTS, instead
  4373 isatool document copies the Isabelle style files to the target
  4374 location;
  4375 
  4376 
  4377 *** Isar ***
  4378 
  4379 * Pure/Provers: improved proof by cases and induction;
  4380   - 'case' command admits impromptu naming of parameters (such as
  4381     "case (Suc n)");
  4382   - 'induct' method divinates rule instantiation from the inductive
  4383     claim; no longer requires excessive ?P bindings for proper
  4384     instantiation of cases;
  4385   - 'induct' method properly enumerates all possibilities of set/type
  4386     rules; as a consequence facts may be also passed through *type*
  4387     rules without further ado;
  4388   - 'induct' method now derives symbolic cases from the *rulified*
  4389     rule (before it used to rulify cases stemming from the internal
  4390     atomized version); this means that the context of a non-atomic
  4391     statement becomes is included in the hypothesis, avoiding the
  4392     slightly cumbersome show "PROP ?case" form;
  4393   - 'induct' may now use elim-style induction rules without chaining
  4394     facts, using ``missing'' premises from the goal state; this allows
  4395     rules stemming from inductive sets to be applied in unstructured
  4396     scripts, while still benefitting from proper handling of non-atomic
  4397     statements; NB: major inductive premises need to be put first, all
  4398     the rest of the goal is passed through the induction;
  4399   - 'induct' proper support for mutual induction involving non-atomic
  4400     rule statements (uses the new concept of simultaneous goals, see
  4401     below);
  4402   - append all possible rule selections, but only use the first
  4403     success (no backtracking);
  4404   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4405   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4406   - added 'print_induct_rules' (covered by help item in recent Proof
  4407     General versions);
  4408   - moved induct/cases attributes to Pure, methods to Provers;
  4409   - generic method setup instantiated for FOL and HOL;
  4410 
  4411 * Pure: support multiple simultaneous goal statements, for example
  4412 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4413 meta-level mechanism, this acts as if several individual goals had
  4414 been stated separately; in particular common proof methods need to be
  4415 repeated in order to cover all claims; note that a single elimination
  4416 step is *not* sufficient to establish the two conjunctions, so this
  4417 fails:
  4418 
  4419   assume "A & B" then have A and B ..   (*".." fails*)
  4420 
  4421 better use "obtain" in situations as above; alternative refer to
  4422 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4423 
  4424 * Pure: proper integration with ``locales''; unlike the original
  4425 version by Florian Kammller, Isar locales package high-level proof
  4426 contexts rather than raw logical ones (e.g. we admit to include
  4427 attributes everywhere); operations on locales include merge and
  4428 rename; support for implicit arguments (``structures''); simultaneous
  4429 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4430 some examples;
  4431 
  4432 * Pure: the following commands have been ``localized'', supporting a
  4433 target locale specification "(in name)": 'lemma', 'theorem',
  4434 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4435 stored both within the locale and at the theory level (exported and
  4436 qualified by the locale name);
  4437 
  4438 * Pure: theory goals may now be specified in ``long'' form, with
  4439 ad-hoc contexts consisting of arbitrary locale elements. for example
  4440 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4441 definitions may be given, too); the result is a meta-level rule with
  4442 the context elements being discharged in the obvious way;
  4443 
  4444 * Pure: new proof command 'using' allows to augment currently used
  4445 facts after a goal statement ('using' is syntactically analogous to
  4446 'apply', but acts on the goal's facts only); this allows chained facts
  4447 to be separated into parts given before and after a claim, as in
  4448 ``from a and b have C using d and e <proof>'';
  4449 
  4450 * Pure: renamed "antecedent" case to "rule_context";
  4451 
  4452 * Pure: new 'judgment' command records explicit information about the
  4453 object-logic embedding (used by several tools internally); no longer
  4454 use hard-wired "Trueprop";
  4455 
  4456 * Pure: added 'corollary' command;
  4457 
  4458 * Pure: fixed 'token_translation' command;
  4459 
  4460 * Pure: removed obsolete 'exported' attribute;
  4461 
  4462 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4463 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4464 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4465 
  4466 * Pure: method 'atomize' presents local goal premises as object-level
  4467 statements (atomic meta-level propositions); setup controlled via
  4468 rewrite rules declarations of 'atomize' attribute; example
  4469 application: 'induct' method with proper rule statements in improper
  4470 proof *scripts*;
  4471 
  4472 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4473 now consider the syntactic context of assumptions, giving a better
  4474 chance to get type-inference of the arguments right (this is
  4475 especially important for locales);
  4476 
  4477 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4478 mode;
  4479 
  4480 * Pure/obtain: the formal conclusion "thesis", being marked as
  4481 ``internal'', may no longer be reference directly in the text;
  4482 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4483 situations;
  4484 
  4485 * Pure: generic 'sym' attribute which declares a rule both as pure
  4486 'elim?' and for the 'symmetric' operation;
  4487 
  4488 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4489 text; the fixed correlation with particular command syntax has been
  4490 discontinued;
  4491 
  4492 * Pure: new method 'rules' is particularly well-suited for proof
  4493 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4494 but often produces more compact proof terms with less detours;
  4495 
  4496 * Pure/Provers/classical: simplified integration with pure rule
  4497 attributes and methods; the classical "intro?/elim?/dest?"
  4498 declarations coincide with the pure ones; the "rule" method no longer
  4499 includes classically swapped intros; "intro" and "elim" methods no
  4500 longer pick rules from the context; also got rid of ML declarations
  4501 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4502 INCOMPATIBILITY;
  4503 
  4504 * Provers/classical: attribute 'swapped' produces classical inversions
  4505 of introduction rules;
  4506 
  4507 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4508 rules instead of full simplifier context; 'iff' attribute handles
  4509 conditional rules;
  4510 
  4511 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4512 
  4513 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4514 "(permissive)" option to recover old behavior;
  4515 
  4516 * HOL: 'inductive' no longer features separate (collective) attributes
  4517 for 'intros' (was found too confusing);
  4518 
  4519 * HOL: properly declared induction rules less_induct and
  4520 wf_induct_rule;
  4521 
  4522 
  4523 *** HOL ***
  4524 
  4525 * HOL: moved over to sane numeral syntax; the new policy is as
  4526 follows:
  4527 
  4528   - 0 and 1 are polymorphic constants, which are defined on any
  4529   numeric type (nat, int, real etc.);
  4530 
  4531   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4532   binary representation internally;
  4533 
  4534   - type nat has special constructor Suc, and generally prefers Suc 0
  4535   over 1::nat and Suc (Suc 0) over 2::nat;
  4536 
  4537 This change may cause significant problems of INCOMPATIBILITY; here
  4538 are some hints on converting existing sources:
  4539 
  4540   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4541   entities, so expressions involving "-" (unary or binary minus) need
  4542   to be spaced properly;
  4543 
  4544   - existing occurrences of "1" may need to be constraint "1::nat" or
  4545   even replaced by Suc 0; similar for old "2";
  4546 
  4547   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4548 
  4549   - remove all special provisions on numerals in proofs;
  4550 
  4551 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4552 representation (depends on bin_arith_simps in the default context);
  4553 
  4554 * HOL: symbolic syntax for x^2 (numeral 2);
  4555 
  4556 * HOL: the class of all HOL types is now called "type" rather than
  4557 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4558 in axclass/classes, instance/arities, and (usually rare) occurrences
  4559 in typings (of consts etc.); internally the class is called
  4560 "HOL.type", ML programs should refer to HOLogic.typeS;
  4561 
  4562 * HOL/record package improvements:
  4563   - new derived operations "fields" to build a partial record section,
  4564     "extend" to promote a fixed record to a record scheme, and
  4565     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4566     declared as simp by default;
  4567   - shared operations ("more", "fields", etc.) now need to be always
  4568     qualified) --- potential INCOMPATIBILITY;
  4569   - removed "make_scheme" operations (use "make" with "extend") --
  4570     INCOMPATIBILITY;
  4571   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4572   - provides cases/induct rules for use with corresponding Isar
  4573     methods (for concrete records, record schemes, concrete more
  4574     parts, and schematic more parts -- in that order);
  4575   - internal definitions directly based on a light-weight abstract
  4576     theory of product types over typedef rather than datatype;
  4577 
  4578 * HOL: generic code generator for generating executable ML code from
  4579 specifications; specific support for HOL constructs such as inductive
  4580 datatypes and sets, as well as recursive functions; can be invoked
  4581 via 'generate_code' theory section;
  4582 
  4583 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4584 
  4585 * HOL: consolidated and renamed several theories.  In particular:
  4586         Ord.thy has been absorbed into HOL.thy
  4587         String.thy has been absorbed into List.thy
  4588 
  4589 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4590 (beware of argument permutation!);
  4591 
  4592 * HOL: linorder_less_split superseded by linorder_cases;
  4593 
  4594 * HOL/List: "nodups" renamed to "distinct";
  4595 
  4596 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4597 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4598   - Ex_def has changed, now need to use some_eq_ex
  4599 
  4600 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4601 in this (rare) case use:
  4602 
  4603   delSWrapper "split_all_tac"
  4604   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4605 
  4606 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4607 MAY FAIL;
  4608 
  4609 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4610 Isabelle's type classes, ^ on functions and relations has too general
  4611 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4612 necessary to attach explicit type constraints;
  4613 
  4614 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4615 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4616 renamed accordingly (eg "compI" -> "rel_compI").
  4617 
  4618 * HOL: syntax translations now work properly with numerals and records
  4619 expressions;
  4620 
  4621 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4622 of "lam" -- INCOMPATIBILITY;
  4623 
  4624 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4625 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4626 renamed "Product_Type.unit";
  4627 
  4628 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4629 
  4630 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4631 the "cases" method);
  4632 
  4633 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4634 Florian Kammller);
  4635 
  4636 * HOL/IMP: updated and converted to new-style theory format; several
  4637 parts turned into readable document, with proper Isar proof texts and
  4638 some explanations (by Gerwin Klein);
  4639 
  4640 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4641 
  4642 * HOL-Hyperreal is now a logic image;
  4643 
  4644 
  4645 *** HOLCF ***
  4646 
  4647 * Isar: consts/constdefs supports mixfix syntax for continuous
  4648 operations;
  4649 
  4650 * Isar: domain package adapted to new-style theory format, e.g. see
  4651 HOLCF/ex/Dnat.thy;
  4652 
  4653 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4654 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4655 lift.induct_tac, always use UU instead of Undef;
  4656 
  4657 * HOLCF/IMP: updated and converted to new-style theory;
  4658 
  4659 
  4660 *** ZF ***
  4661 
  4662 * Isar: proper integration of logic-specific tools and packages,
  4663 including theory commands '(co)inductive', '(co)datatype',
  4664 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4665 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4666 
  4667 * theory Main no longer includes AC; for the Axiom of Choice, base
  4668 your theory on Main_ZFC;
  4669 
  4670 * the integer library now covers quotients and remainders, with many
  4671 laws relating division to addition, multiplication, etc.;
  4672 
  4673 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4674 typeless version of the formalism;
  4675 
  4676 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4677 format;
  4678 
  4679 * ZF/Induct: new directory for examples of inductive definitions,
  4680 including theory Multiset for multiset orderings; converted to
  4681 new-style theory format;
  4682 
  4683 * ZF: many new theorems about lists, ordinals, etc.;
  4684 
  4685 
  4686 *** General ***
  4687 
  4688 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4689 variable proof controls level of detail: 0 = no proofs (only oracle
  4690 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4691 also ref manual for further ML interfaces;
  4692 
  4693 * Pure/axclass: removed obsolete ML interface
  4694 goal_subclass/goal_arity;
  4695 
  4696 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4697 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4698 separate tokens, so expressions involving minus need to be spaced
  4699 properly;
  4700 
  4701 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4702 rather than "infixl" or "infixr";
  4703 
  4704 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4705 sort constraint specifications in type inference; e.g. "x::_::foo"
  4706 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4707 type variable);
  4708 
  4709 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4710 control output of nested => (types); the default behavior is
  4711 "type_brackets";
  4712 
  4713 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4714 tokens into AST constants;
  4715 
  4716 * Pure/syntax: prefer later declarations of translations and print
  4717 translation functions; potential INCOMPATIBILITY: need to reverse
  4718 multiple declarations for same syntax element constant;
  4719 
  4720 * Pure/show_hyps reset by default (in accordance to existing Isar
  4721 practice);
  4722 
  4723 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4724 addSafter;
  4725 
  4726 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4727 as well;
  4728 
  4729 * system: tested support for MacOS X; should be able to get Isabelle +
  4730 Proof General to work in a plain Terminal after installing Poly/ML
  4731 (e.g. from the Isabelle distribution area) and GNU bash alone
  4732 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4733 support requires further installations, e.g. from
  4734 http://fink.sourceforge.net/);
  4735 
  4736 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4737 
  4738 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4739 of 40 MB), cf. ML_OPTIONS;
  4740 
  4741 * system: Proof General keywords specification is now part of the
  4742 Isabelle distribution (see etc/isar-keywords.el);
  4743 
  4744 * system: support for persistent Proof General sessions (refrain from
  4745 outdating all loaded theories on startup); user may create writable
  4746 logic images like this: ``isabelle -q HOL Test'';
  4747 
  4748 * system: smart selection of Isabelle process versus Isabelle
  4749 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4750 run both "isabelle" and "Isabelle" even if file names are badly
  4751 damaged (executable inspects the case of the first letter of its own
  4752 name); added separate "isabelle-process" and "isabelle-interface";
  4753 
  4754 * system: refrain from any attempt at filtering input streams; no
  4755 longer support ``8bit'' encoding of old isabelle font, instead proper
  4756 iso-latin characters may now be used; the related isatools
  4757 "symbolinput" and "nonascii" have disappeared as well;
  4758 
  4759 * system: removed old "xterm" interface (the print modes "xterm" and
  4760 "xterm_color" are still available for direct use in a suitable
  4761 terminal);
  4762 
  4763 
  4764 
  4765 New in Isabelle99-2 (February 2001)
  4766 -----------------------------------
  4767 
  4768 *** Overview of INCOMPATIBILITIES ***
  4769 
  4770 * HOL: please note that theories in the Library and elsewhere often use the
  4771 new-style (Isar) format; to refer to their theorems in an ML script you must
  4772 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4773 
  4774 * HOL: inductive package no longer splits induction rule aggressively,
  4775 but only as far as specified by the introductions given; the old
  4776 format may be recovered via ML function complete_split_rule or attribute
  4777 'split_rule (complete)';
  4778 
  4779 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4780 gfp_Tarski to gfp_unfold;
  4781 
  4782 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4783 
  4784 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4785 relation); infix "^^" has been renamed "``"; infix "``" has been
  4786 renamed "`"; "univalent" has been renamed "single_valued";
  4787 
  4788 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4789 operation;
  4790 
  4791 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4792 
  4793 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4794 
  4795 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4796 consequence, it is no longer monotonic wrt. the local goal context
  4797 (which is now passed through the inductive cases);
  4798 
  4799 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4800 \<gg> to \<ggreater>;
  4801 
  4802 
  4803 *** Document preparation ***
  4804 
  4805 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4806 available: are "it" for near math-mode best-style output, "sl" for
  4807 slanted text style, and "tt" for plain type-writer; if no
  4808 \isabellestyle command is given, output is according to slanted
  4809 type-writer);
  4810 
  4811 * support sub/super scripts (for single symbols only), input syntax is
  4812 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4813 
  4814 * some more standard symbols; see Appendix A of the system manual for
  4815 the complete list of symbols defined in isabellesym.sty;
  4816 
  4817 * improved isabelle style files; more abstract symbol implementation
  4818 (should now use \isamath{...} and \isatext{...} in custom symbol
  4819 definitions);
  4820 
  4821 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4822 state; Note that presentation of goal states does not conform to
  4823 actual human-readable proof documents.  Please do not include goal
  4824 states into document output unless you really know what you are doing!
  4825 
  4826 * proper indentation of antiquoted output with proportional LaTeX
  4827 fonts;
  4828 
  4829 * no_document ML operator temporarily disables LaTeX document
  4830 generation;
  4831 
  4832 * isatool unsymbolize tunes sources for plain ASCII communication;
  4833 
  4834 
  4835 *** Isar ***
  4836 
  4837 * Pure: Isar now suffers initial goal statements to contain unbound
  4838 schematic variables (this does not conform to actual readable proof
  4839 documents, due to unpredictable outcome and non-compositional proof
  4840 checking); users who know what they are doing may use schematic goals
  4841 for Prolog-style synthesis of proven results;
  4842 
  4843 * Pure: assumption method (an implicit finishing) now handles actual
  4844 rules as well;
  4845 
  4846 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4847 initial goal, declare "that" only as Pure intro (only for single
  4848 steps); the "that" rule assumption may now be involved in implicit
  4849 finishing, thus ".." becomes a feasible for trivial obtains;
  4850 
  4851 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4852 instance proofs may be performed by "..";
  4853 
  4854 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4855 statements as well;
  4856 
  4857 * Pure: more robust selection of calculational rules;
  4858 
  4859 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4860 rule (as well as the assumption rule);
  4861 
  4862 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4863 lemmas, using the graph browser tool;
  4864 
  4865 * Pure: predict failure of "show" in interactive mode;
  4866 
  4867 * Pure: 'thms_containing' now takes actual terms as arguments;
  4868 
  4869 * HOL: improved method 'induct' --- now handles non-atomic goals
  4870 (potential INCOMPATIBILITY); tuned error handling;
  4871 
  4872 * HOL: cases and induct rules now provide explicit hints about the
  4873 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4874 any remaining facts are inserted into the goal verbatim;
  4875 
  4876 * HOL: local contexts (aka cases) may now contain term bindings as
  4877 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4878 the result to be shown in each case;
  4879 
  4880 * HOL: added 'recdef_tc' command;
  4881 
  4882 * isatool convert assists in eliminating legacy ML scripts;
  4883 
  4884 
  4885 *** HOL ***
  4886 
  4887 * HOL/Library: a collection of generic theories to be used together
  4888 with main HOL; the theory loader path already includes this directory
  4889 by default; the following existing theories have been moved here:
  4890 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4891 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4892 
  4893 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4894 modelling and verification task performed in Isabelle/HOL +
  4895 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4896 
  4897 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4898 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4899 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4900 'domain', this makes the theory consistent with mathematical
  4901 literature;
  4902 
  4903 * HOL basics: added overloaded operations "inverse" and "divide"
  4904 (infix "/"), syntax for generic "abs" operation, generic summation
  4905 operator \<Sum>;
  4906 
  4907 * HOL/typedef: simplified package, provide more useful rules (see also
  4908 HOL/subset.thy);
  4909 
  4910 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4911 now expressed as a proper nested rule (old-style tactic scripts may
  4912 require atomize_strip_tac to cope with non-atomic premises);
  4913 
  4914 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4915 to "split_conv" (old name still available for compatibility);
  4916 
  4917 * HOL: improved concrete syntax for strings (e.g. allows translation
  4918 rules with string literals);
  4919 
  4920 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4921  and Fleuriot's mechanization of analysis, including the transcendental
  4922  functions for the reals;
  4923 
  4924 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4925 
  4926 
  4927 *** CTT ***
  4928 
  4929 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4930 "lam" is displayed as TWO lambda-symbols
  4931 
  4932 * CTT: theory Main now available, containing everything (that is, Bool
  4933 and Arith);
  4934 
  4935 
  4936 *** General ***
  4937 
  4938 * Pure: the Simplifier has been implemented properly as a derived rule
  4939 outside of the actual kernel (at last!); the overall performance
  4940 penalty in practical applications is about 50%, while reliability of
  4941 the Isabelle inference kernel has been greatly improved;
  4942 
  4943 * print modes "brackets" and "no_brackets" control output of nested =>
  4944 (types) and ==> (props); the default behaviour is "brackets";
  4945 
  4946 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4947 as assumptions as well;
  4948 
  4949 * system: support Poly/ML 4.0;
  4950 
  4951 * system: isatool install handles KDE version 1 or 2;
  4952 
  4953 
  4954 
  4955 New in Isabelle99-1 (October 2000)
  4956 ----------------------------------
  4957 
  4958 *** Overview of INCOMPATIBILITIES ***
  4959 
  4960 * HOL: simplification of natural numbers is much changed; to partly
  4961 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4962 issue the following ML commands:
  4963 
  4964   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4965   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4966 
  4967 * HOL: simplification no longer dives into case-expressions; this is
  4968 controlled by "t.weak_case_cong" for each datatype t;
  4969 
  4970 * HOL: nat_less_induct renamed to less_induct;
  4971 
  4972 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4973 fixsome to patch .thy and .ML sources automatically;
  4974 
  4975   select_equality  -> some_equality
  4976   select_eq_Ex     -> some_eq_ex
  4977   selectI2EX       -> someI2_ex
  4978   selectI2         -> someI2
  4979   selectI          -> someI
  4980   select1_equality -> some1_equality
  4981   Eps_sym_eq       -> some_sym_eq_trivial
  4982   Eps_eq           -> some_eq_trivial
  4983 
  4984 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4985 
  4986 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4987 instead);
  4988 
  4989 * HOL: the recursion equations generated by 'recdef' are now called
  4990 f.simps instead of f.rules;
  4991 
  4992 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4993 
  4994 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4995 sometimes be needed;
  4996 
  4997 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4998 
  4999 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5000 
  5001 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5002 product is now "<*>" instead of "Times"; the lexicographic product is
  5003 now "<*lex*>" instead of "**";
  5004 
  5005 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5006 of main HOL, but was unused); better use HOL's datatype package;
  5007 
  5008 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5009 the old syntax may be recovered as follows:
  5010 
  5011   syntax (symbols)
  5012     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5013       (infixl "\\<oplus>" 100)
  5014 
  5015 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5016 
  5017 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5018 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5019 internally;
  5020 
  5021 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5022 changed from A/r to A//r;
  5023 
  5024 * ZF: new treatment of arithmetic (nat & int) may break some old
  5025 proofs;
  5026 
  5027 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5028 rulify -> rule_format, elimify -> elim_format, ...);
  5029 
  5030 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5031 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5032 should have to change intro!! to intro? only); replaced "delrule" by
  5033 "rule del";
  5034 
  5035 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5036 
  5037 * Provers: strengthened force_tac by using new first_best_tac;
  5038 
  5039 * LaTeX document preparation: several changes of isabelle.sty (see
  5040 lib/texinputs);
  5041 
  5042 
  5043 *** Document preparation ***
  5044 
  5045 * formal comments (text blocks etc.) in new-style theories may now
  5046 contain antiquotations of thm/prop/term/typ/text to be presented
  5047 according to latex print mode; concrete syntax is like this:
  5048 @{term[show_types] "f(x) = a + x"};
  5049 
  5050 * isatool mkdir provides easy setup of Isabelle session directories,
  5051 including proper document sources;
  5052 
  5053 * generated LaTeX sources are now deleted after successful run
  5054 (isatool document -c); may retain a copy somewhere else via -D option
  5055 of isatool usedir;
  5056 
  5057 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5058 style files, achieving self-contained LaTeX sources and simplifying
  5059 LaTeX debugging;
  5060 
  5061 * old-style theories now produce (crude) LaTeX output as well;
  5062 
  5063 * browser info session directories are now self-contained (may be put
  5064 on WWW server seperately); improved graphs of nested sessions; removed
  5065 graph for 'all sessions';
  5066 
  5067 * several improvements in isabelle style files; \isabellestyle{it}
  5068 produces fake math mode output; \isamarkupheader is now \section by
  5069 default; see lib/texinputs/isabelle.sty etc.;
  5070 
  5071 
  5072 *** Isar ***
  5073 
  5074 * Isar/Pure: local results and corresponding term bindings are now
  5075 subject to Hindley-Milner polymorphism (similar to ML); this
  5076 accommodates incremental type-inference very nicely;
  5077 
  5078 * Isar/Pure: new derived language element 'obtain' supports
  5079 generalized existence reasoning;
  5080 
  5081 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5082 support accumulation of results, without applying any rules yet;
  5083 useful to collect intermediate results without explicit name
  5084 references, and for use with transitivity rules with more than 2
  5085 premises;
  5086 
  5087 * Isar/Pure: scalable support for case-analysis type proofs: new
  5088 'case' language element refers to local contexts symbolically, as
  5089 produced by certain proof methods; internally, case names are attached
  5090 to theorems as "tags";
  5091 
  5092 * Isar/Pure: theory command 'hide' removes declarations from
  5093 class/type/const name spaces;
  5094 
  5095 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5096 indicate potential overloading;
  5097 
  5098 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5099 
  5100 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5101 "{a,b,c}" instead of {a,b,c};
  5102 
  5103 * Isar/Pure now provides its own version of intro/elim/dest
  5104 attributes; useful for building new logics, but beware of confusion
  5105 with the version in Provers/classical;
  5106 
  5107 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5108 case name 'antecedent';
  5109 
  5110 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5111 to the current context is now done automatically);
  5112 
  5113 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5114 for definining proof methods in ML;
  5115 
  5116 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5117 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5118 most cases, one should have to change intro!! to intro? only);
  5119 replaced "delrule" by "rule del";
  5120 
  5121 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5122 'symmetric' attribute (the latter supercedes [RS sym]);
  5123 
  5124 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5125 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5126 well (including splits);
  5127 
  5128 * Isar/Provers: Simplifier and Classical methods now support all kind
  5129 of modifiers used in the past, including 'cong', 'iff', etc.
  5130 
  5131 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5132 of Simplifier and Classical reasoner);
  5133 
  5134 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5135 now support named cases; major packages (inductive, datatype, primrec,
  5136 recdef) support case names and properly name parameters;
  5137 
  5138 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5139 monotonicity conditions are extracted to be proven at end of
  5140 calculations;
  5141 
  5142 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5143 method anyway;
  5144 
  5145 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5146 split_if split_if_asm; datatype package provides theorems foo.splits =
  5147 foo.split foo.split_asm for each datatype;
  5148 
  5149 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5150 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5151 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5152 use "(cases (simplified))" method in proper proof texts);
  5153 
  5154 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5155 
  5156 * Isar: names of theorems etc. may be natural numbers as well;
  5157 
  5158 * Isar: 'pr' command: optional arguments for goals_limit and
  5159 ProofContext.prems_limit; no longer prints theory contexts, but only
  5160 proof states;
  5161 
  5162 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5163 additional print modes to be specified; e.g. "pr(latex)" will print
  5164 proof state according to the Isabelle LaTeX style;
  5165 
  5166 * Isar: improved support for emulating tactic scripts, including proof
  5167 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5168 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5169 (for HOL datatypes);
  5170 
  5171 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5172 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5173 'proof method scripts' have to be in depth-first order;
  5174 
  5175 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5176 
  5177 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5178 should instead use individual commands for printing items
  5179 (print_commands, print_methods etc.);
  5180 
  5181 * Isar: added 'nothing' --- the empty list of theorems;
  5182 
  5183 
  5184 *** HOL ***
  5185 
  5186 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5187 corresponding virtual machine and a specification of its bytecode
  5188 verifier and a lightweight bytecode verifier, including proofs of
  5189 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5190 Cornelia Pusch (see also the homepage of project Bali at
  5191 http://isabelle.in.tum.de/Bali/);
  5192 
  5193 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5194 Clemens Ballarin;
  5195 
  5196 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5197 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5198 Rasmussen;
  5199 
  5200 * HOL/Lattice: fundamental concepts of lattice theory and order
  5201 structures, including duals, properties of bounds versus algebraic
  5202 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5203 Theorem for complete lattices etc.; may also serve as a demonstration
  5204 for abstract algebraic reasoning using axiomatic type classes, and
  5205 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5206 
  5207 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5208 von Oheimb;
  5209 
  5210 * HOL/IMPP: extension of IMP with local variables and mutually
  5211 recursive procedures, by David von Oheimb;
  5212 
  5213 * HOL/Lambda: converted into new-style theory and document;
  5214 
  5215 * HOL/ex/Multiquote: example of multiple nested quotations and
  5216 anti-quotations -- basically a generalized version of de-Bruijn
  5217 representation; very useful in avoiding lifting of operations;
  5218 
  5219 * HOL/record: added general record equality rule to simpset; fixed
  5220 select-update simplification procedure to handle extended records as
  5221 well; admit "r" as field name;
  5222 
  5223 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5224 other numeric types and also as the identity of groups, rings, etc.;
  5225 
  5226 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5227 Types nat and int belong to this axclass;
  5228 
  5229 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5230    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5231    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5232   two terms #m*u and #n*u are replaced by #(m+n)*u
  5233     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5234   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5235     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5236 
  5237 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5238 powerful prover for predicate logic but knows nothing of clasets; see
  5239 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5240 
  5241 * HOL: new version of "case_tac" subsumes both boolean case split and
  5242 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5243 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5244 
  5245 * HOL: simplification no longer dives into case-expressions: only the
  5246 selector expression is simplified, but not the remaining arms; to
  5247 enable full simplification of case-expressions for datatype t, you may
  5248 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5249 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5250 
  5251 * HOL/recdef: the recursion equations generated by 'recdef' for
  5252 function 'f' are now called f.simps instead of f.rules; if all
  5253 termination conditions are proved automatically, these simplification
  5254 rules are added to the simpset, as in primrec; rules may be named
  5255 individually as well, resulting in a separate list of theorems for
  5256 each equation;
  5257 
  5258 * HOL/While is a new theory that provides a while-combinator. It
  5259 permits the definition of tail-recursive functions without the
  5260 provision of a termination measure. The latter is necessary once the
  5261 invariant proof rule for while is applied.
  5262 
  5263 * HOL: new (overloaded) notation for the set of elements below/above
  5264 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5265 
  5266 * HOL: theorems impI, allI, ballI bound as "strip";
  5267 
  5268 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5269 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5270 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5271 
  5272 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5273 
  5274 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5275 main HOL, but was unused);
  5276 
  5277 * HOL: fewer consts declared as global (e.g. have to refer to
  5278 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5279 
  5280 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5281 in case of overlap with user translations (e.g. judgements over
  5282 tuples); (note that the underlying logical represenation is still
  5283 bogus);
  5284 
  5285 
  5286 *** ZF ***
  5287 
  5288 * ZF: simplification automatically cancels common terms in arithmetic
  5289 expressions over nat and int;
  5290 
  5291 * ZF: new treatment of nat to minimize type-checking: all operators
  5292 coerce their operands to a natural number using the function natify,
  5293 making the algebraic laws unconditional;
  5294 
  5295 * ZF: as above, for int: operators coerce their operands to an integer
  5296 using the function intify;
  5297 
  5298 * ZF: the integer library now contains many of the usual laws for the
  5299 orderings, including $<=, and monotonicity laws for $+ and $*;
  5300 
  5301 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5302 simplification;
  5303 
  5304 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5305 to the simplifier and classical reasoner simultaneously;
  5306 
  5307 
  5308 *** General ***
  5309 
  5310 * Provers: blast_tac now handles actual object-logic rules as
  5311 assumptions; note that auto_tac uses blast_tac internally as well;
  5312 
  5313 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5314 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5315 
  5316 * Provers: delrules now handles destruct rules as well (no longer need
  5317 explicit make_elim);
  5318 
  5319 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5320   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5321 use instead the strong form,
  5322   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5323 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5324 from destruct-rules;
  5325 
  5326 * Provers: Simplifier.easy_setup provides a fast path to basic
  5327 Simplifier setup for new object-logics;
  5328 
  5329 * Pure: AST translation rules no longer require constant head on LHS;
  5330 
  5331 * Pure: improved name spaces: ambiguous output is qualified; support
  5332 for hiding of names;
  5333 
  5334 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5335 XSYMBOL_HOME; no longer need to do manual configuration in most
  5336 situations;
  5337 
  5338 * system: compression of ML heaps images may now be controlled via -c
  5339 option of isabelle and isatool usedir (currently only observed by
  5340 Poly/ML);
  5341 
  5342 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5343 useful for remote X11);
  5344 
  5345 * system: provide TAGS file for Isabelle sources;
  5346 
  5347 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5348 order;
  5349 
  5350 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5351 timing flag supersedes proof_timing and Toplevel.trace;
  5352 
  5353 * ML: new combinators |>> and |>>> for incremental transformations
  5354 with secondary results (e.g. certain theory extensions):
  5355 
  5356 * ML: PureThy.add_defs gets additional argument to indicate potential
  5357 overloading (usually false);
  5358 
  5359 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5360 results;
  5361 
  5362 
  5363 
  5364 New in Isabelle99 (October 1999)
  5365 --------------------------------
  5366 
  5367 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5368 
  5369 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5370 are no longer simplified.  (This allows the simplifier to unfold recursive
  5371 functional programs.)  To restore the old behaviour, declare
  5372 
  5373     Delcongs [if_weak_cong];
  5374 
  5375 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5376 complement;
  5377 
  5378 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5379 
  5380 * HOL/datatype: mutual_induct_tac no longer exists --
  5381   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5382 
  5383 * HOL/typedef: fixed type inference for representing set; type
  5384 arguments now have to occur explicitly on the rhs as type constraints;
  5385 
  5386 * ZF: The con_defs part of an inductive definition may no longer refer
  5387 to constants declared in the same theory;
  5388 
  5389 * HOL, ZF: the function mk_cases, generated by the inductive
  5390 definition package, has lost an argument.  To simplify its result, it
  5391 uses the default simpset instead of a supplied list of theorems.
  5392 
  5393 * HOL/List: the constructors of type list are now Nil and Cons;
  5394 
  5395 * Simplifier: the type of the infix ML functions
  5396         setSSolver addSSolver setSolver addSolver
  5397 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5398 for packaging solvers. A solver is created via
  5399         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5400 where the string argument is only a comment.
  5401 
  5402 
  5403 *** Proof tools ***
  5404 
  5405 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5406 decision procedure for linear arithmetic. Currently it is used for
  5407 types `nat', `int', and `real' in HOL (see below); it can, should and
  5408 will be instantiated for other types and logics as well.
  5409 
  5410 * The simplifier now accepts rewrite rules with flexible heads, eg
  5411      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5412   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5413   matching.
  5414 
  5415 
  5416 *** General ***
  5417 
  5418 * New Isabelle/Isar subsystem provides an alternative to traditional
  5419 tactical theorem proving; together with the ProofGeneral/isar user
  5420 interface it offers an interactive environment for developing human
  5421 readable proof documents (Isar == Intelligible semi-automated
  5422 reasoning); for further information see isatool doc isar-ref,
  5423 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5424 
  5425 * improved and simplified presentation of theories: better HTML markup
  5426 (including colors), graph views in several sizes; isatool usedir now
  5427 provides a proper interface for user theories (via -P option); actual
  5428 document preparation based on (PDF)LaTeX is available as well (for
  5429 new-style theories only); see isatool doc system for more information;
  5430 
  5431 * native support for Proof General, both for classic Isabelle and
  5432 Isabelle/Isar;
  5433 
  5434 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5435 using the graph browser tool;
  5436 
  5437 * Isabelle manuals now also available as PDF;
  5438 
  5439 * theory loader rewritten from scratch (may not be fully
  5440 bug-compatible); old loadpath variable has been replaced by show_path,
  5441 add_path, del_path, reset_path functions; new operations such as
  5442 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5443 isatool doc ref);
  5444 
  5445 * improved isatool install: option -k creates KDE application icon,
  5446 option -p DIR installs standalone binaries;
  5447 
  5448 * added ML_PLATFORM setting (useful for cross-platform installations);
  5449 more robust handling of platform specific ML images for SML/NJ;
  5450 
  5451 * the settings environment is now statically scoped, i.e. it is never
  5452 created again in sub-processes invoked from isabelle, isatool, or
  5453 Isabelle;
  5454 
  5455 * path element specification '~~' refers to '$ISABELLE_HOME';
  5456 
  5457 * in locales, the "assumes" and "defines" parts may be omitted if
  5458 empty;
  5459 
  5460 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5461 long arrows);
  5462 
  5463 * new print_mode "HTML";
  5464 
  5465 * new flag show_tags controls display of tags of theorems (which are
  5466 basically just comments that may be attached by some tools);
  5467 
  5468 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5469 mode and goal output format:
  5470 
  5471 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5472 244c244
  5473 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5474 ---
  5475 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5476 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5477 181c181
  5478 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5479 ---
  5480 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5481 
  5482 * function bind_thms stores lists of theorems (cf. bind_thm);
  5483 
  5484 * new shorthand tactics ftac, eatac, datac, fatac;
  5485 
  5486 * qed (and friends) now accept "" as result name; in that case the
  5487 theorem is not stored, but proper checks and presentation of the
  5488 result still apply;
  5489 
  5490 * theorem database now also indexes constants "Trueprop", "all",
  5491 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5492 
  5493 
  5494 *** HOL ***
  5495 
  5496 ** HOL arithmetic **
  5497 
  5498 * There are now decision procedures for linear arithmetic over nat and
  5499 int:
  5500 
  5501 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5502 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5503 are treated as atomic; subformulae not involving type `nat' or `int'
  5504 are ignored; quantified subformulae are ignored unless they are
  5505 positive universal or negative existential. The tactic has to be
  5506 invoked by hand and can be a little bit slow. In particular, the
  5507 running time is exponential in the number of occurrences of `min' and
  5508 `max', and `-' on `nat'.
  5509 
  5510 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5511 (negated) (in)equalities among the premises and the conclusion into
  5512 account (i.e. no compound formulae) and does not know about `min' and
  5513 `max', and `-' on `nat'. It is fast and is used automatically by the
  5514 simplifier.
  5515 
  5516 NB: At the moment, these decision procedures do not cope with mixed
  5517 nat/int formulae where the two parts interact, such as `m < n ==>
  5518 int(m) < int(n)'.
  5519 
  5520 * HOL/Numeral provides a generic theory of numerals (encoded
  5521 efficiently as bit strings); setup for types nat/int/real is in place;
  5522 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5523 int, existing theories and proof scripts may require a few additional
  5524 type constraints;
  5525 
  5526 * integer division and remainder can now be performed on constant
  5527 arguments;
  5528 
  5529 * many properties of integer multiplication, division and remainder
  5530 are now available;
  5531 
  5532 * An interface to the Stanford Validity Checker (SVC) is available through the
  5533 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5534 are proved automatically.  SVC must be installed separately, and its results
  5535 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5536 invocation of the underlying oracle).  For SVC see
  5537   http://verify.stanford.edu/SVC
  5538 
  5539 * IsaMakefile: the HOL-Real target now builds an actual image;
  5540 
  5541 
  5542 ** HOL misc **
  5543 
  5544 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5545 (in Isabelle/Isar) -- by Gertrud Bauer;
  5546 
  5547 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5548 analysis for assembly languages with subtypes;
  5549 
  5550 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5551 -- avoids syntactic ambiguities and treats state, transition, and
  5552 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5553 changed syntax and (many) tactics;
  5554 
  5555 * HOL/inductive: Now also handles more general introduction rules such
  5556   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5557   theorems are now maintained within the theory (maintained via the
  5558   "mono" attribute);
  5559 
  5560 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5561   (using function types) such as
  5562 
  5563   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5564 
  5565 * HOL/record: record_simproc (part of the default simpset) takes care
  5566 of selectors applied to updated records; record_split_tac is no longer
  5567 part of the default claset; update_defs may now be removed from the
  5568 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5569 
  5570   claset_ref () := claset() addSWrapper record_split_wrapper;
  5571   Delsimprocs [record_simproc]
  5572 
  5573 * HOL/typedef: fixed type inference for representing set; type
  5574 arguments now have to occur explicitly on the rhs as type constraints;
  5575 
  5576 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5577 names rather than an ML expression;
  5578 
  5579 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5580 supplied later.  Program schemes can be defined, such as
  5581     "While B C s = (if B s then While B C (C s) else s)"
  5582 where the well-founded relation can be chosen after B and C have been given.
  5583 
  5584 * HOL/List: the constructors of type list are now Nil and Cons;
  5585 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5586 course, ML tools referring to List.list.op # etc. have to be adapted;
  5587 
  5588 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5589 disabled by default; run isabelle with option -m HOL to get back to
  5590 the original Gordon/HOL-style output;
  5591 
  5592 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5593 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5594 
  5595 * HOL basic syntax simplified (more orthogonal): all variants of
  5596 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5597 Eps operator is provided as well: "SOME x. P[x]";
  5598 
  5599 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5600 
  5601 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5602 thus available for user theories;
  5603 
  5604 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5605 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5606 time;
  5607 
  5608 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5609 several times and then mp;
  5610 
  5611 
  5612 *** LK ***
  5613 
  5614 * the notation <<...>> is now available as a notation for sequences of
  5615 formulas;
  5616 
  5617 * the simplifier is now installed
  5618 
  5619 * the axiom system has been generalized (thanks to Soren Heilmann)
  5620 
  5621 * the classical reasoner now has a default rule database
  5622 
  5623 
  5624 *** ZF ***
  5625 
  5626 * new primrec section allows primitive recursive functions to be given
  5627 directly (as in HOL) over datatypes and the natural numbers;
  5628 
  5629 * new tactics induct_tac and exhaust_tac for induction (or case
  5630 analysis) over datatypes and the natural numbers;
  5631 
  5632 * the datatype declaration of type T now defines the recursor T_rec;
  5633 
  5634 * simplification automatically does freeness reasoning for datatype
  5635 constructors;
  5636 
  5637 * automatic type-inference, with AddTCs command to insert new
  5638 type-checking rules;
  5639 
  5640 * datatype introduction rules are now added as Safe Introduction rules
  5641 to the claset;
  5642 
  5643 * the syntax "if P then x else y" is now available in addition to
  5644 if(P,x,y);
  5645 
  5646 
  5647 *** Internal programming interfaces ***
  5648 
  5649 * tuned simplifier trace output; new flag debug_simp;
  5650 
  5651 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5652 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5653 
  5654 * AxClass.axclass_tac lost the theory argument;
  5655 
  5656 * tuned current_goals_markers semantics: begin / end goal avoids
  5657 printing empty lines;
  5658 
  5659 * removed prs and prs_fn hook, which was broken because it did not
  5660 include \n in its semantics, forcing writeln to add one
  5661 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5662 string -> unit if you really want to output text without newline;
  5663 
  5664 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5665 plain output, interface builders may have to enable 'isabelle_font'
  5666 mode to get Isabelle font glyphs as before;
  5667 
  5668 * refined token_translation interface; INCOMPATIBILITY: output length
  5669 now of type real instead of int;
  5670 
  5671 * theory loader actions may be traced via new ThyInfo.add_hook
  5672 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5673 your own database of information attached to *whole* theories -- as
  5674 opposed to intra-theory data slots offered via TheoryDataFun;
  5675 
  5676 * proper handling of dangling sort hypotheses (at last!);
  5677 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5678 extra sort hypotheses that can be witnessed from the type signature;
  5679 the force_strip_shyps flag is gone, any remaining shyps are simply
  5680 left in the theorem (with a warning issued by strip_shyps_warning);
  5681 
  5682 
  5683 
  5684 New in Isabelle98-1 (October 1998)
  5685 ----------------------------------
  5686 
  5687 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5688 
  5689 * several changes of automated proof tools;
  5690 
  5691 * HOL: major changes to the inductive and datatype packages, including
  5692 some minor incompatibilities of theory syntax;
  5693 
  5694 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5695 called `inj_on';
  5696 
  5697 * HOL: removed duplicate thms in Arith:
  5698   less_imp_add_less  should be replaced by  trans_less_add1
  5699   le_imp_add_le      should be replaced by  trans_le_add1
  5700 
  5701 * HOL: unary minus is now overloaded (new type constraints may be
  5702 required);
  5703 
  5704 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5705 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5706 now taken as an integer constant.
  5707 
  5708 * Pure: ML function 'theory_of' renamed to 'theory';
  5709 
  5710 
  5711 *** Proof tools ***
  5712 
  5713 * Simplifier:
  5714   1. Asm_full_simp_tac is now more aggressive.
  5715      1. It will sometimes reorient premises if that increases their power to
  5716         simplify.
  5717      2. It does no longer proceed strictly from left to right but may also
  5718         rotate premises to achieve further simplification.
  5719      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5720      old Asm_full_simp_tac in that it does not rotate premises.
  5721   2. The simplifier now knows a little bit about nat-arithmetic.
  5722 
  5723 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5724 allows for selected deletion of wrappers, by introduction of names for
  5725 wrapper functionals.  This implies that addbefore, addSbefore,
  5726 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5727 and that adding two tactics with the same name overwrites the first
  5728 one (emitting a warning).
  5729   type wrapper = (int -> tactic) -> (int -> tactic)
  5730   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5731   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5732   delWrapper, delSWrapper: claset *  string            -> claset
  5733   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5734 
  5735 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5736 semantics; addbefore now affects only the unsafe part of step_tac
  5737 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5738 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5739 by Force_tac;
  5740 
  5741 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5742 compWrapper; added safe wrapper (and access functions for it);
  5743 
  5744 * HOL/split_all_tac is now much faster and fails if there is nothing
  5745 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5746 and the names of the automatically generated variables have changed.
  5747 split_all_tac has moved within claset() from unsafe wrappers to safe
  5748 wrappers, which means that !!-bound variables are split much more
  5749 aggressively, and safe_tac and clarify_tac now split such variables.
  5750 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5751 Note: the same holds for record_split_tac, which does the job of
  5752 split_all_tac for record fields.
  5753 
  5754 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5755 permanently to the default simpset using Addsplits just like
  5756 Addsimps. They can be removed via Delsplits just like
  5757 Delsimps. Lower-case versions are also available.
  5758 
  5759 * HOL/Simplifier: The rule split_if is now part of the default
  5760 simpset. This means that the simplifier will eliminate all occurrences
  5761 of if-then-else in the conclusion of a goal. To prevent this, you can
  5762 either remove split_if completely from the default simpset by
  5763 `Delsplits [split_if]' or remove it in a specific call of the
  5764 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5765 other case splitting rules to/from the default simpset: every datatype
  5766 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5767 t is the name of the datatype).
  5768 
  5769 * Classical reasoner / Simplifier combination: new force_tac (and
  5770 derivatives Force_tac, force) combines rewriting and classical
  5771 reasoning (and whatever other tools) similarly to auto_tac, but is
  5772 aimed to solve the given subgoal completely.
  5773 
  5774 
  5775 *** General ***
  5776 
  5777 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5778 and `goalw': the theory is no longer needed as an explicit argument -
  5779 the current theory context is used; assumptions are no longer returned
  5780 at the ML-level unless one of them starts with ==> or !!; it is
  5781 recommended to convert to these new commands using isatool fixgoal
  5782 (backup your sources first!);
  5783 
  5784 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5785 the current theory context, and 'theory' to lookup stored theories;
  5786 
  5787 * new theory section 'locale' for declaring constants, assumptions and
  5788 definitions that have local scope;
  5789 
  5790 * new theory section 'nonterminals' for purely syntactic types;
  5791 
  5792 * new theory section 'setup' for generic ML setup functions
  5793 (e.g. package initialization);
  5794 
  5795 * the distribution now includes Isabelle icons: see
  5796 lib/logo/isabelle-{small,tiny}.xpm;
  5797 
  5798 * isatool install - install binaries with absolute references to
  5799 ISABELLE_HOME/bin;
  5800 
  5801 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5802 
  5803 * print mode 'emacs' reserved for Isamode;
  5804 
  5805 * support multiple print (ast) translations per constant name;
  5806 
  5807 * theorems involving oracles are now printed with a suffixed [!];
  5808 
  5809 
  5810 *** HOL ***
  5811 
  5812 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5813 
  5814 * HOL/inductive package reorganized and improved: now supports mutual
  5815 definitions such as
  5816 
  5817   inductive EVEN ODD
  5818     intrs
  5819       null "0 : EVEN"
  5820       oddI "n : EVEN ==> Suc n : ODD"
  5821       evenI "n : ODD ==> Suc n : EVEN"
  5822 
  5823 new theorem list "elims" contains an elimination rule for each of the
  5824 recursive sets; inductive definitions now handle disjunctive premises
  5825 correctly (also ZF);
  5826 
  5827 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5828 "mutual_induct" no longer exists - the induction rule is always
  5829 contained in "induct";
  5830 
  5831 
  5832 * HOL/datatype package re-implemented and greatly improved: now
  5833 supports mutually recursive datatypes such as
  5834 
  5835   datatype
  5836     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5837             | SUM ('a aexp) ('a aexp)
  5838             | DIFF ('a aexp) ('a aexp)
  5839             | NUM 'a
  5840   and
  5841     'a bexp = LESS ('a aexp) ('a aexp)
  5842             | AND ('a bexp) ('a bexp)
  5843             | OR ('a bexp) ('a bexp)
  5844 
  5845 as well as indirectly recursive datatypes such as
  5846 
  5847   datatype
  5848     ('a, 'b) term = Var 'a
  5849                   | App 'b ((('a, 'b) term) list)
  5850 
  5851 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5852 induction on mutually / indirectly recursive datatypes.
  5853 
  5854 Primrec equations are now stored in theory and can be accessed via
  5855 <function_name>.simps.
  5856 
  5857 INCOMPATIBILITIES:
  5858 
  5859   - Theories using datatypes must now have theory Datatype as an
  5860     ancestor.
  5861   - The specific <typename>.induct_tac no longer exists - use the
  5862     generic induct_tac instead.
  5863   - natE has been renamed to nat.exhaust - use exhaust_tac
  5864     instead of res_inst_tac ... natE. Note that the variable
  5865     names in nat.exhaust differ from the names in natE, this
  5866     may cause some "fragile" proofs to fail.
  5867   - The theorems split_<typename>_case and split_<typename>_case_asm
  5868     have been renamed to <typename>.split and <typename>.split_asm.
  5869   - Since default sorts of type variables are now handled correctly,
  5870     some datatype definitions may have to be annotated with explicit
  5871     sort constraints.
  5872   - Primrec definitions no longer require function name and type
  5873     of recursive argument.
  5874 
  5875 Consider using isatool fixdatatype to adapt your theories and proof
  5876 scripts to the new package (backup your sources first!).
  5877 
  5878 
  5879 * HOL/record package: considerably improved implementation; now
  5880 includes concrete syntax for record types, terms, updates; theorems
  5881 for surjective pairing and splitting !!-bound record variables; proof
  5882 support is as follows:
  5883 
  5884   1) standard conversions (selectors or updates applied to record
  5885 constructor terms) are part of the standard simpset;
  5886 
  5887   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5888 made part of standard simpset and claset via addIffs;
  5889 
  5890   3) a tactic for record field splitting (record_split_tac) is part of
  5891 the standard claset (addSWrapper);
  5892 
  5893 To get a better idea about these rules you may retrieve them via
  5894 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5895 the name of your record type.
  5896 
  5897 The split tactic 3) conceptually simplifies by the following rule:
  5898 
  5899   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5900 
  5901 Thus any record variable that is bound by meta-all will automatically
  5902 blow up into some record constructor term, consequently the
  5903 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5904 solve record problems automatically.
  5905 
  5906 
  5907 * reorganized the main HOL image: HOL/Integ and String loaded by
  5908 default; theory Main includes everything;
  5909 
  5910 * automatic simplification of integer sums and comparisons, using cancellation;
  5911 
  5912 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5913 
  5914 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5915 
  5916 * many new identities for unions, intersections, set difference, etc.;
  5917 
  5918 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5919 called split_if, split_split, split_sum_case and split_nat_case (to go
  5920 with add/delsplits);
  5921 
  5922 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5923 (?x::unit) = (); this is made part of the default simpset, which COULD
  5924 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5925 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5926 unit_abs_eta_conv is added in order to counter the effect of
  5927 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5928 %u.f();
  5929 
  5930 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5931 makes more sense);
  5932 
  5933 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5934   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5935   disjointness reasoning but breaking a few old proofs.
  5936 
  5937 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5938 to 'converse' from 'inverse' (for compatibility with ZF and some
  5939 literature);
  5940 
  5941 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5942 the well-founded relation;
  5943 
  5944 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5945     Compl A.  The "Compl" syntax remains available as input syntax for this
  5946     release ONLY.
  5947 
  5948 * HOL/Update: new theory of function updates:
  5949     f(a:=b) == %x. if x=a then b else f x
  5950 may also be iterated as in f(a:=b,c:=d,...);
  5951 
  5952 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5953 
  5954 * HOL/List:
  5955   - new function list_update written xs[i:=v] that updates the i-th
  5956     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5957   - new function `upt' written [i..j(] which generates the list
  5958     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5959     bound write [i..j], which is a shorthand for [i..j+1(].
  5960   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5961 
  5962 * HOL/Arith:
  5963   - removed 'pred' (predecessor) function;
  5964   - generalized some theorems about n-1;
  5965   - many new laws about "div" and "mod";
  5966   - new laws about greatest common divisors (see theory ex/Primes);
  5967 
  5968 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5969 instead of "inverse";
  5970 
  5971 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5972   of the multiset ordering;
  5973 
  5974 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5975   (not included by default);
  5976 
  5977 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5978 
  5979 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5980   programs, i.e. different program variables may have different types.
  5981 
  5982 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5983   [previously, this check worked only if the rewrite rule was unconditional]
  5984   Now rew can involve either definitions or equalities (either == or =).
  5985 
  5986 
  5987 *** ZF ***
  5988 
  5989 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5990   only the theorems proved on ZF.ML;
  5991 
  5992 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5993   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5994   disjointness reasoning but breaking a few old proofs.
  5995 
  5996 * ZF/Update: new theory of function updates
  5997     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5998   may also be iterated as in f(a:=b,c:=d,...);
  5999 
  6000 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6001 
  6002 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6003   [previously, this check worked only if the rewrite rule was unconditional]
  6004   Now rew can involve either definitions or equalities (either == or =).
  6005 
  6006 * case_tac provided for compatibility with HOL
  6007     (like the old excluded_middle_tac, but with subgoals swapped)
  6008 
  6009 
  6010 *** Internal programming interfaces ***
  6011 
  6012 * Pure: several new basic modules made available for general use, see
  6013 also src/Pure/README;
  6014 
  6015 * improved the theory data mechanism to support encapsulation (data
  6016 kind name replaced by private Object.kind, acting as authorization
  6017 key); new type-safe user interface via functor TheoryDataFun; generic
  6018 print_data function becomes basically useless;
  6019 
  6020 * removed global_names compatibility flag -- all theory declarations
  6021 are qualified by default;
  6022 
  6023 * module Pure/Syntax now offers quote / antiquote translation
  6024 functions (useful for Hoare logic etc. with implicit dependencies);
  6025 see HOL/ex/Antiquote for an example use;
  6026 
  6027 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  6028 cterm -> thm;
  6029 
  6030 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  6031 subgoal;
  6032 
  6033 * Display.print_goals function moved to Locale.print_goals;
  6034 
  6035 * standard print function for goals supports current_goals_markers
  6036 variable for marking begin of proof, end of proof, start of goal; the
  6037 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  6038 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  6039 for example;
  6040 
  6041 
  6042 
  6043 New in Isabelle98 (January 1998)
  6044 --------------------------------
  6045 
  6046 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6047 
  6048 * changed lexical syntax of terms / types: dots made part of long
  6049 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6050 
  6051 * simpset (and claset) reference variable replaced by functions
  6052 simpset / simpset_ref;
  6053 
  6054 * no longer supports theory aliases (via merge) and non-trivial
  6055 implicit merge of thms' signatures;
  6056 
  6057 * most internal names of constants changed due to qualified names;
  6058 
  6059 * changed Pure/Sequence interface (see Pure/seq.ML);
  6060 
  6061 
  6062 *** General Changes ***
  6063 
  6064 * hierachically structured name spaces (for consts, types, axms, thms
  6065 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6066 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6067 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6068 long_names for fully qualified output names; NOTE: ML programs
  6069 (special tactics, packages etc.) referring to internal names may have
  6070 to be adapted to cope with fully qualified names; in case of severe
  6071 backward campatibility problems try setting 'global_names' at compile
  6072 time to have enrything declared within a flat name space; one may also
  6073 fine tune name declarations in theories via the 'global' and 'local'
  6074 section;
  6075 
  6076 * reimplemented the implicit simpset and claset using the new anytype
  6077 data filed in signatures; references simpset:simpset ref etc. are
  6078 replaced by functions simpset:unit->simpset and
  6079 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6080 to patch your ML files accordingly;
  6081 
  6082 * HTML output now includes theory graph data for display with Java
  6083 applet or isatool browser; data generated automatically via isatool
  6084 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6085 
  6086 * defs may now be conditional; improved rewrite_goals_tac to handle
  6087 conditional equations;
  6088 
  6089 * defs now admits additional type arguments, using TYPE('a) syntax;
  6090 
  6091 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6092 creates a new theory node; implicit merge of thms' signatures is
  6093 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6094 transfer:theory->thm->thm in (rare) cases;
  6095 
  6096 * improved handling of draft signatures / theories; draft thms (and
  6097 ctyps, cterms) are automatically promoted to real ones;
  6098 
  6099 * slightly changed interfaces for oracles: admit many per theory, named
  6100 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6101 
  6102 * print_goals: optional output of const types (set show_consts and
  6103 show_types);
  6104 
  6105 * improved output of warnings (###) and errors (***);
  6106 
  6107 * subgoal_tac displays a warning if the new subgoal has type variables;
  6108 
  6109 * removed old README and Makefiles;
  6110 
  6111 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6112 
  6113 * removed obsolete init_pps and init_database;
  6114 
  6115 * deleted the obsolete tactical STATE, which was declared by
  6116     fun STATE tacfun st = tacfun st st;
  6117 
  6118 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6119 (which abbreviates $HOME);
  6120 
  6121 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6122 use isatool fixseq to adapt your ML programs (this works for fully
  6123 qualified references to the Sequence structure only!);
  6124 
  6125 * use_thy no longer requires writable current directory; it always
  6126 reloads .ML *and* .thy file, if either one is out of date;
  6127 
  6128 
  6129 *** Classical Reasoner ***
  6130 
  6131 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6132 tactics that use classical reasoning to simplify a subgoal without
  6133 splitting it into several subgoals;
  6134 
  6135 * Safe_tac: like safe_tac but uses the default claset;
  6136 
  6137 
  6138 *** Simplifier ***
  6139 
  6140 * added simplification meta rules:
  6141     (asm_)(full_)simplify: simpset -> thm -> thm;
  6142 
  6143 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6144 logics (again);
  6145 
  6146 * added prems argument to simplification procedures;
  6147 
  6148 * HOL, FOL, ZF: added infix function `addsplits':
  6149   instead of `<simpset> setloop (split_tac <thms>)'
  6150   you can simply write `<simpset> addsplits <thms>'
  6151 
  6152 
  6153 *** Syntax ***
  6154 
  6155 * TYPE('a) syntax for type reflection terms;
  6156 
  6157 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6158 
  6159 * pretty printer: changed order of mixfix annotation preference (again!);
  6160 
  6161 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6162 
  6163 
  6164 *** HOL ***
  6165 
  6166 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6167   with `addloop' of the simplifier to faciliate case splitting in premises.
  6168 
  6169 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6170 
  6171 * HOL/Auth: new protocol proofs including some for the Internet
  6172   protocol TLS;
  6173 
  6174 * HOL/Map: new theory of `maps' a la VDM;
  6175 
  6176 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6177 cancelling out common nat summands from =, <, <= (in)equalities, or
  6178 differences; simplification procedures nat_cancel_factor for
  6179 cancelling common factor from =, <, <= (in)equalities over natural
  6180 sums; nat_cancel contains both kinds of procedures, it is installed by
  6181 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6182 
  6183 * HOL/simplifier: terms of the form
  6184   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6185   are rewritten to
  6186   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6187   and those of the form
  6188   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6189   are rewritten to
  6190   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6191 
  6192 * HOL/datatype
  6193   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6194 
  6195   P(t_case f1 ... fn x) =
  6196      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6197         ...
  6198        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6199      )
  6200 
  6201   and a theorem `split_t_case_asm' of the form
  6202 
  6203   P(t_case f1 ... fn x) =
  6204     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6205         ...
  6206        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6207      )
  6208   which can be added to a simpset via `addsplits'. The existing theorems
  6209   expand_list_case and expand_option_case have been renamed to
  6210   split_list_case and split_option_case.
  6211 
  6212 * HOL/Arithmetic:
  6213   - `pred n' is automatically converted to `n-1'.
  6214     Users are strongly encouraged not to use `pred' any longer,
  6215     because it will disappear altogether at some point.
  6216   - Users are strongly encouraged to write "0 < n" rather than
  6217     "n ~= 0". Theorems and proof tools have been modified towards this
  6218     `standard'.
  6219 
  6220 * HOL/Lists:
  6221   the function "set_of_list" has been renamed "set" (and its theorems too);
  6222   the function "nth" now takes its arguments in the reverse order and
  6223   has acquired the infix notation "!" as in "xs!n".
  6224 
  6225 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6226 
  6227 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6228   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6229 
  6230 * HOL/record: extensible records with schematic structural subtyping
  6231 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6232 still lacks various theorems and concrete record syntax;
  6233 
  6234 
  6235 *** HOLCF ***
  6236 
  6237 * removed "axioms" and "generated by" sections;
  6238 
  6239 * replaced "ops" section by extended "consts" section, which is capable of
  6240   handling the continuous function space "->" directly;
  6241 
  6242 * domain package:
  6243   . proves theorems immediately and stores them in the theory,
  6244   . creates hierachical name space,
  6245   . now uses normal mixfix annotations (instead of cinfix...),
  6246   . minor changes to some names and values (for consistency),
  6247   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6248   . separator between mutual domain defs: changed "," to "and",