NEWS
author haftmann
Mon Oct 26 11:19:24 2009 +0100 (2009-10-26)
changeset 33177 edbd2c09176b
parent 33084 cd1579e0997a
child 33201 e3d741e9d2fe
permissions -rw-r--r--
re-moved theory Fin_Fun to AFP
     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_into" and function "inv" is now an
   157 abbreviation for "inv_into 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.  Old quickcheck can be re-activated importing
   169 theory Library/SML_Quickcheck.
   170 
   171 * Renamed theorems:
   172 Suc_eq_add_numeral_1 -> Suc_eq_plus1
   173 Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   174 Suc_plus1 -> Suc_eq_plus1
   175 
   176 * Moved theorems:
   177 Wellfounded.in_inv_image -> Relation.in_inv_image
   178 
   179 * New sledgehammer option "Full Types" in Proof General settings menu.
   180 Causes full type information to be output to the ATPs.  This slows
   181 ATPs down considerably but eliminates a source of unsound "proofs"
   182 that fail later.
   183 
   184 * New method metisFT: A version of metis that uses full type information
   185 in order to avoid failures of proof reconstruction.
   186 
   187 * Discontinued ancient tradition to suffix certain ML module names
   188 with "_package", e.g.:
   189 
   190     DatatypePackage ~> Datatype
   191     InductivePackage ~> Inductive
   192 
   193 INCOMPATIBILITY.
   194 
   195 * Discontinued abbreviation "arbitrary" of constant
   196 "undefined". INCOMPATIBILITY, use "undefined" directly.
   197 
   198 * New evaluator "approximate" approximates an real valued term using
   199 the same method as the approximation method.
   200 
   201 * Method "approximate" supports now arithmetic expressions as
   202 boundaries of intervals and implements interval splitting and Taylor
   203 series expansion.
   204 
   205 * Changed DERIV_intros to a dynamic fact (via Named_Thms).  Each of
   206 the theorems in DERIV_intros assumes composition with an additional
   207 function and matches a variable to the derivative, which has to be
   208 solved by the simplifier.  Hence (auto intro!: DERIV_intros) computes
   209 the derivative of most elementary terms.
   210 
   211 * Maclauren.DERIV_tac and Maclauren.deriv_tac was removed, they are
   212 replaced by: (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   213 
   214 
   215 *** ML ***
   216 
   217 * Removed some old-style infix operations using polymorphic equality.
   218 INCOMPATIBILITY.
   219 
   220 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   221 provides a high-level programming interface to synchronized state
   222 variables with atomic update.  This works via pure function
   223 application within a critical section -- its runtime should be as
   224 short as possible; beware of deadlocks if critical code is nested,
   225 either directly or indirectly via other synchronized variables!
   226 
   227 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   228 wraps raw ML references, explicitly indicating their non-thread-safe
   229 behaviour.  The Isar toplevel keeps this structure open, to
   230 accommodate Proof General as well as quick and dirty interactive
   231 experiments with references.
   232 
   233 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   234 parallel tactical reasoning.
   235 
   236 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   237 are similar to SUBPROOF, but are slightly more flexible: only the
   238 specified parts of the subgoal are imported into the context, and the
   239 body tactic may introduce new subgoals and schematic variables.
   240 
   241 * Old tactical METAHYPS, which does not observe the proof context, has
   242 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   243 or Subgoal.FOCUS etc.
   244 
   245 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   246 functors have their own ML name space there is no point to mark them
   247 separately.)  Minor INCOMPATIBILITY.
   248 
   249 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   250 
   251 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   252 cominators for "args".  INCOMPATIBILITY, need to use simplified
   253 Attrib/Method.setup introduced in Isabelle2009.
   254 
   255 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   256 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   257 last resort.  INCOMPATIBILITY.
   258 
   259 * Display.pretty_thm now requires a proper context (cf. former
   260 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   261 or even Display.pretty_thm_without_context as last resort.
   262 INCOMPATIBILITY.
   263 
   264 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   265 Syntax.pretty_typ/term directly, preferably with proper context
   266 instead of global theory.
   267 
   268 * Operations of structure Skip_Proof (formerly SkipProof) no longer
   269 require quick_and_dirty mode, which avoids critical setmp.
   270 
   271 
   272 *** System ***
   273 
   274 * Support for additional "Isabelle components" via etc/components, see
   275 also the system manual.
   276 
   277 * The isabelle makeall tool now operates on all components with
   278 IsaMakefile, not just hardwired "logics".
   279 
   280 * Discontinued support for Poly/ML 4.x versions.
   281 
   282 * Removed "compress" option from isabelle-process and isabelle usedir;
   283 this is always enabled.
   284 
   285 * More fine-grained control of proof parallelism, cf.
   286 Goal.parallel_proofs in ML and usedir option -q LEVEL.
   287 
   288 
   289 
   290 New in Isabelle2009 (April 2009)
   291 --------------------------------
   292 
   293 *** General ***
   294 
   295 * Simplified main Isabelle executables, with less surprises on
   296 case-insensitive file-systems (such as Mac OS).
   297 
   298   - The main Isabelle tool wrapper is now called "isabelle" instead of
   299     "isatool."
   300 
   301   - The former "isabelle" alias for "isabelle-process" has been
   302     removed (should rarely occur to regular users).
   303 
   304   - The former "isabelle-interface" and its alias "Isabelle" have been
   305     removed (interfaces are now regular Isabelle tools).
   306 
   307 Within scripts and make files, the Isabelle environment variables
   308 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   309 respectively.  (The latter are still available as legacy feature.)
   310 
   311 The old isabelle-interface wrapper could react in confusing ways if
   312 the interface was uninstalled or changed otherwise.  Individual
   313 interface tool configuration is now more explicit, see also the
   314 Isabelle system manual.  In particular, Proof General is now available
   315 via "isabelle emacs".
   316 
   317 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   318 purge installed copies of Isabelle executables and re-run "isabelle
   319 install -p ...", or use symlinks.
   320 
   321 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   322 old ~/isabelle, which was slightly non-standard and apt to cause
   323 surprises on case-insensitive file-systems (such as Mac OS).
   324 
   325 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   326 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   327 care is required when using older releases of Isabelle.  Note that
   328 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   329 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   330 
   331 * Proofs of fully specified statements are run in parallel on
   332 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   333 a regular 4-core machine, if the initial heap space is made reasonably
   334 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   335 
   336 * The main reference manuals ("isar-ref", "implementation", and
   337 "system") have been updated and extended.  Formally checked references
   338 as hyperlinks are now available uniformly.
   339 
   340 
   341 *** Pure ***
   342 
   343 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   344 respects.  The most important changes are listed below.  See the
   345 Tutorial on Locales ("locales" manual) for details.
   346 
   347 - In locale expressions, instantiation replaces renaming.  Parameters
   348 must be declared in a for clause.  To aid compatibility with previous
   349 parameter inheritance, in locale declarations, parameters that are not
   350 'touched' (instantiation position "_" or omitted) are implicitly added
   351 with their syntax at the beginning of the for clause.
   352 
   353 - Syntax from abbreviations and definitions in locales is available in
   354 locale expressions and context elements.  The latter is particularly
   355 useful in locale declarations.
   356 
   357 - More flexible mechanisms to qualify names generated by locale
   358 expressions.  Qualifiers (prefixes) may be specified in locale
   359 expressions, and can be marked as mandatory (syntax: "name!:") or
   360 optional (syntax "name?:").  The default depends for plain "name:"
   361 depends on the situation where a locale expression is used: in
   362 commands 'locale' and 'sublocale' prefixes are optional, in
   363 'interpretation' and 'interpret' prefixes are mandatory.  The old
   364 implicit qualifiers derived from the parameter names of a locale are
   365 no longer generated.
   366 
   367 - Command "sublocale l < e" replaces "interpretation l < e".  The
   368 instantiation clause in "interpretation" and "interpret" (square
   369 brackets) is no longer available.  Use locale expressions.
   370 
   371 - When converting proof scripts, mandatory qualifiers in
   372 'interpretation' and 'interpret' should be retained by default, even
   373 if this is an INCOMPATIBILITY compared to former behavior.  In the
   374 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   375 in locale expressions range over a single locale instance only.
   376 
   377 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   378 In existing theorem specifications replace the includes element by the
   379 respective context elements of the included locale, omitting those
   380 that are already present in the theorem specification.  Multiple
   381 assume elements of a locale should be replaced by a single one
   382 involving the locale predicate.  In the proof body, declarations (most
   383 notably theorems) may be regained by interpreting the respective
   384 locales in the proof context as required (command "interpret").
   385 
   386 If using "includes" in replacement of a target solely because the
   387 parameter types in the theorem are not as general as in the target,
   388 consider declaring a new locale with additional type constraints on
   389 the parameters (context element "constrains").
   390 
   391 - Discontinued "locale (open)".  INCOMPATIBILITY.
   392 
   393 - Locale interpretation commands no longer attempt to simplify goal.
   394 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   395 methods intro_locales and unfold_locales to clarify.
   396 
   397 - Locale interpretation commands no longer accept interpretation
   398 attributes.  INCOMPATIBILITY.
   399 
   400 * Class declaration: so-called "base sort" must not be given in import
   401 list any longer, but is inferred from the specification.  Particularly
   402 in HOL, write
   403 
   404     class foo = ...
   405 
   406 instead of
   407 
   408     class foo = type + ...
   409 
   410 * Class target: global versions of theorems stemming do not carry a
   411 parameter prefix any longer.  INCOMPATIBILITY.
   412 
   413 * Class 'instance' command no longer accepts attached definitions.
   414 INCOMPATIBILITY, use proper 'instantiation' target instead.
   415 
   416 * Recovered hiding of consts, which was accidentally broken in
   417 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   418 makes c inaccessible; consider using ``hide (open) const c'' instead.
   419 
   420 * Slightly more coherent Pure syntax, with updated documentation in
   421 isar-ref manual.  Removed locales meta_term_syntax and
   422 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   423 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   424 directly in regular applications.
   425 
   426 * There is a new syntactic category "float_const" for signed decimal
   427 fractions (e.g. 123.45 or -123.45).
   428 
   429 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   430 interface with 'setup' command instead.
   431 
   432 * Command 'local_setup' is similar to 'setup', but operates on a local
   433 theory context.
   434 
   435 * The 'axiomatization' command now only works within a global theory
   436 context.  INCOMPATIBILITY.
   437 
   438 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   439 hypotheses.  Sorts required in the course of reasoning need to be
   440 covered by the constraints in the initial statement, completed by the
   441 type instance information of the background theory.  Non-trivial sort
   442 hypotheses, which rarely occur in practice, may be specified via
   443 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   444 
   445   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   446 
   447 The result contains an implicit sort hypotheses as before --
   448 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   449 normalization.
   450 
   451 * Generalized Isar history, with support for linear undo, direct state
   452 addressing etc.
   453 
   454 * Changed defaults for unify configuration options:
   455 
   456   unify_trace_bound = 50 (formerly 25)
   457   unify_search_bound = 60 (formerly 30)
   458 
   459 * Different bookkeeping for code equations (INCOMPATIBILITY):
   460 
   461   a) On theory merge, the last set of code equations for a particular
   462      constant is taken (in accordance with the policy applied by other
   463      parts of the code generator framework).
   464 
   465   b) Code equations stemming from explicit declarations (e.g. code
   466      attribute) gain priority over default code equations stemming
   467      from definition, primrec, fun etc.
   468 
   469 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   470 
   471 * Unified theorem tables for both code generators.  Thus [code
   472 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   473 
   474 * Command 'find_consts' searches for constants based on type and name
   475 patterns, e.g.
   476 
   477     find_consts "_ => bool"
   478 
   479 By default, matching is against subtypes, but it may be restricted to
   480 the whole type.  Searching by name is possible.  Multiple queries are
   481 conjunctive and queries may be negated by prefixing them with a
   482 hyphen:
   483 
   484     find_consts strict: "_ => bool" name: "Int" -"int => int"
   485 
   486 * New 'find_theorems' criterion "solves" matches theorems that
   487 directly solve the current goal (modulo higher-order unification).
   488 
   489 * Auto solve feature for main theorem statements: whenever a new goal
   490 is stated, "find_theorems solves" is called; any theorems that could
   491 solve the lemma directly are listed as part of the goal state.
   492 Cf. associated options in Proof General Isabelle settings menu,
   493 enabled by default, with reasonable timeout for pathological cases of
   494 higher-order unification.
   495 
   496 
   497 *** Document preparation ***
   498 
   499 * Antiquotation @{lemma} now imitates a regular terminal proof,
   500 demanding keyword 'by' and supporting the full method expression
   501 syntax just like the Isar command 'by'.
   502 
   503 
   504 *** HOL ***
   505 
   506 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   507 points Main and Complex_Main remain as before.
   508 
   509 * Logic image HOL-Plain provides a minimal HOL with the most important
   510 tools available (inductive, datatype, primrec, ...).  This facilitates
   511 experimentation and tool development.  Note that user applications
   512 (and library theories) should never refer to anything below theory
   513 Main, as before.
   514 
   515 * Logic image HOL-Main stops at theory Main, and thus facilitates
   516 experimentation due to shorter build times.
   517 
   518 * Logic image HOL-NSA contains theories of nonstandard analysis which
   519 were previously part of former HOL-Complex.  Entry point Hyperreal
   520 remains valid, but theories formerly using Complex_Main should now use
   521 new entry point Hypercomplex.
   522 
   523 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   524 Posix processes.  Avoids potentially expensive forking of the ML
   525 process.  New thread-based implementation also works on non-Unix
   526 platforms (Cygwin).  Provers are no longer hardwired, but defined
   527 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   528 commands are covered in the isar-ref manual.
   529 
   530 * Wrapper scripts for remote SystemOnTPTP service allows to use
   531 sledgehammer without local ATP installation (Vampire etc.). Other
   532 provers may be included via suitable ML wrappers, see also
   533 src/HOL/ATP_Linkup.thy.
   534 
   535 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   536 menu.
   537 
   538 * The metis method no longer fails because the theorem is too trivial
   539 (contains the empty clause).
   540 
   541 * The metis method now fails in the usual manner, rather than raising
   542 an exception, if it determines that it cannot prove the theorem.
   543 
   544 * Method "coherent" implements a prover for coherent logic (see also
   545 src/Tools/coherent.ML).
   546 
   547 * Constants "undefined" and "default" replace "arbitrary".  Usually
   548 "undefined" is the right choice to replace "arbitrary", though
   549 logically there is no difference.  INCOMPATIBILITY.
   550 
   551 * Command "value" now integrates different evaluation mechanisms.  The
   552 result of the first successful evaluation mechanism is printed.  In
   553 square brackets a particular named evaluation mechanisms may be
   554 specified (currently, [SML], [code] or [nbe]).  See further
   555 src/HOL/ex/Eval_Examples.thy.
   556 
   557 * Normalization by evaluation now allows non-leftlinear equations.
   558 Declare with attribute [code nbe].
   559 
   560 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   561 as the structured Isar versions "cases" and "induct", cf. the
   562 corresponding "cases" and "induct" attributes.  Mutual induction rules
   563 are now presented as a list of individual projections
   564 (e.g. foo_bar.inducts for types foo and bar); the old format with
   565 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   566 rare situations a different rule is selected --- notably nested tuple
   567 elimination instead of former prod.exhaust: use explicit (case_tac t
   568 rule: prod.exhaust) here.
   569 
   570 * Attributes "cases", "induct", "coinduct" support "del" option.
   571 
   572 * Removed fact "case_split_thm", which duplicates "case_split".
   573 
   574 * The option datatype has been moved to a new theory Option.  Renamed
   575 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   576 
   577 * New predicate "strict_mono" classifies strict functions on partial
   578 orders.  With strict functions on linear orders, reasoning about
   579 (in)equalities is facilitated by theorems "strict_mono_eq",
   580 "strict_mono_less_eq" and "strict_mono_less".
   581 
   582 * Some set operations are now proper qualified constants with
   583 authentic syntax.  INCOMPATIBILITY:
   584 
   585     op Int ~>   Set.Int
   586     op Un ~>    Set.Un
   587     INTER ~>    Set.INTER
   588     UNION ~>    Set.UNION
   589     Inter ~>    Set.Inter
   590     Union ~>    Set.Union
   591     {} ~>       Set.empty
   592     UNIV ~>     Set.UNIV
   593 
   594 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   595 theory Set.
   596 
   597 * Auxiliary class "itself" has disappeared -- classes without any
   598 parameter are treated as expected by the 'class' command.
   599 
   600 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   601 
   602 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   603 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   604 
   605 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   606 method "approximation".  It proves formulas on real values by using
   607 interval arithmetic.  In the formulas are also the transcendental
   608 functions sin, cos, tan, atan, ln, exp and the constant pi are
   609 allowed. For examples see
   610 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   611 
   612 * Theory "Reflection" now resides in HOL/Library.
   613 
   614 * Entry point to Word library now simply named "Word".
   615 INCOMPATIBILITY.
   616 
   617 * Made source layout more coherent with logical distribution
   618 structure:
   619 
   620     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   621     src/HOL/Library/Code_Message.thy ~> src/HOL/
   622     src/HOL/Library/GCD.thy ~> src/HOL/
   623     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   624     src/HOL/Library/Parity.thy ~> src/HOL/
   625     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   626     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   627     src/HOL/Real/Lubs.thy ~> src/HOL/
   628     src/HOL/Real/PReal.thy ~> src/HOL/
   629     src/HOL/Real/Rational.thy ~> src/HOL/
   630     src/HOL/Real/RComplete.thy ~> src/HOL/
   631     src/HOL/Real/RealDef.thy ~> src/HOL/
   632     src/HOL/Real/RealPow.thy ~> src/HOL/
   633     src/HOL/Real/Real.thy ~> src/HOL/
   634     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   635     src/HOL/Complex/Complex.thy ~> src/HOL/
   636     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   637     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   638     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   639     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   640     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   641     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   642     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   643     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   644     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   645     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   646     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   647     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   648     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   649     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   650     src/HOL/Real/Float ~> src/HOL/Library/
   651     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   652     src/HOL/Real/RealVector.thy ~> src/HOL/
   653 
   654     src/HOL/arith_data.ML ~> src/HOL/Tools
   655     src/HOL/hologic.ML ~> src/HOL/Tools
   656     src/HOL/simpdata.ML ~> src/HOL/Tools
   657     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   658     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   659     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   660     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   661     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   662     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   663     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   664 
   665     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   666     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   667     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   668     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   669     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   670     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   671 
   672 * If methods "eval" and "evaluation" encounter a structured proof
   673 state with !!/==>, only the conclusion is evaluated to True (if
   674 possible), avoiding strange error messages.
   675 
   676 * Method "sizechange" automates termination proofs using (a
   677 modification of) the size-change principle.  Requires SAT solver.  See
   678 src/HOL/ex/Termination.thy for examples.
   679 
   680 * Simplifier: simproc for let expressions now unfolds if bound
   681 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   682 
   683 * Method "arith": Linear arithmetic now ignores all inequalities when
   684 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   685 
   686 * New attribute "arith" for facts that should always be used
   687 automatically by arithmetic. It is intended to be used locally in
   688 proofs, e.g.
   689 
   690   assumes [arith]: "x > 0"
   691 
   692 Global usage is discouraged because of possible performance impact.
   693 
   694 * New classes "top" and "bot" with corresponding operations "top" and
   695 "bot" in theory Orderings; instantiation of class "complete_lattice"
   696 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   697 
   698 * Changed definition lemma "less_fun_def" in order to provide an
   699 instance for preorders on functions; use lemma "less_le" instead.
   700 INCOMPATIBILITY.
   701 
   702 * Theory Orderings: class "wellorder" moved here, with explicit
   703 induction rule "less_induct" as assumption.  For instantiation of
   704 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   705 INCOMPATIBILITY.
   706 
   707 * Theory Orderings: added class "preorder" as superclass of "order".
   708 INCOMPATIBILITY: Instantiation proofs for order, linorder
   709 etc. slightly changed.  Some theorems named order_class.* now named
   710 preorder_class.*.
   711 
   712 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   713 "diag" to "Id_on".
   714 
   715 * Theory Finite_Set: added a new fold combinator of type
   716 
   717   ('a => 'b => 'b) => 'b => 'a set => 'b
   718 
   719 Occasionally this is more convenient than the old fold combinator
   720 which is now defined in terms of the new one and renamed to
   721 fold_image.
   722 
   723 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   724 and "ring_simps" have been replaced by "algebra_simps" (which can be
   725 extended with further lemmas!).  At the moment both still exist but
   726 the former will disappear at some point.
   727 
   728 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   729 class recpower.  Type-specific simp rules for various recpower types
   730 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   731 
   732 rat_power_0    -> power_0
   733 rat_power_Suc  -> power_Suc
   734 realpow_0      -> power_0
   735 realpow_Suc    -> power_Suc
   736 complexpow_0   -> power_0
   737 complexpow_Suc -> power_Suc
   738 power_poly_0   -> power_0
   739 power_poly_Suc -> power_Suc
   740 
   741 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   742 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   743 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   744 of lemmas from Divides has been generalized from nat to class
   745 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   746 renames resulting from duplicate elimination:
   747 
   748     dvd_def_mod ~>          dvd_eq_mod_eq_0
   749     zero_dvd_iff ~>         dvd_0_left_iff
   750     dvd_0 ~>                dvd_0_right
   751     DIVISION_BY_ZERO_DIV ~> div_by_0
   752     DIVISION_BY_ZERO_MOD ~> mod_by_0
   753     mult_div ~>             div_mult_self2_is_id
   754     mult_mod ~>             mod_mult_self2_is_0
   755 
   756 * Theory IntDiv: removed many lemmas that are instances of class-based
   757 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   758 rename old lemmas as follows:
   759 
   760 dvd_diff               -> nat_dvd_diff
   761 dvd_zminus_iff         -> dvd_minus_iff
   762 mod_add1_eq            -> mod_add_eq
   763 mod_mult1_eq           -> mod_mult_right_eq
   764 mod_mult1_eq'          -> mod_mult_left_eq
   765 mod_mult_distrib_mod   -> mod_mult_eq
   766 nat_mod_add_left_eq    -> mod_add_left_eq
   767 nat_mod_add_right_eq   -> mod_add_right_eq
   768 nat_mod_div_trivial    -> mod_div_trivial
   769 nat_mod_mod_trivial    -> mod_mod_trivial
   770 zdiv_zadd_self1        -> div_add_self1
   771 zdiv_zadd_self2        -> div_add_self2
   772 zdiv_zmult_self1       -> div_mult_self2_is_id
   773 zdiv_zmult_self2       -> div_mult_self1_is_id
   774 zdvd_triv_left         -> dvd_triv_left
   775 zdvd_triv_right        -> dvd_triv_right
   776 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   777 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   778 zmod_zadd_left_eq      -> mod_add_left_eq
   779 zmod_zadd_right_eq     -> mod_add_right_eq
   780 zmod_zadd_self1        -> mod_add_self1
   781 zmod_zadd_self2        -> mod_add_self2
   782 zmod_zadd1_eq          -> mod_add_eq
   783 zmod_zdiff1_eq         -> mod_diff_eq
   784 zmod_zdvd_zmod         -> mod_mod_cancel
   785 zmod_zmod_cancel       -> mod_mod_cancel
   786 zmod_zmult_self1       -> mod_mult_self2_is_0
   787 zmod_zmult_self2       -> mod_mult_self1_is_0
   788 zmod_1                 -> mod_by_1
   789 zdiv_1                 -> div_by_1
   790 zdvd_abs1              -> abs_dvd_iff
   791 zdvd_abs2              -> dvd_abs_iff
   792 zdvd_refl              -> dvd_refl
   793 zdvd_trans             -> dvd_trans
   794 zdvd_zadd              -> dvd_add
   795 zdvd_zdiff             -> dvd_diff
   796 zdvd_zminus_iff        -> dvd_minus_iff
   797 zdvd_zminus2_iff       -> minus_dvd_iff
   798 zdvd_zmultD            -> dvd_mult_right
   799 zdvd_zmultD2           -> dvd_mult_left
   800 zdvd_zmult_mono        -> mult_dvd_mono
   801 zdvd_0_right           -> dvd_0_right
   802 zdvd_0_left            -> dvd_0_left_iff
   803 zdvd_1_left            -> one_dvd
   804 zminus_dvd_iff         -> minus_dvd_iff
   805 
   806 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   807 
   808 * The real numbers offer decimal input syntax: 12.34 is translated
   809 into 1234/10^2. This translation is not reversed upon output.
   810 
   811 * Theory Library/Polynomial defines an abstract type 'a poly of
   812 univariate polynomials with coefficients of type 'a.  In addition to
   813 the standard ring operations, it also supports div and mod.  Code
   814 generation is also supported, using list-style constructors.
   815 
   816 * Theory Library/Inner_Product defines a class of real_inner for real
   817 inner product spaces, with an overloaded operation inner :: 'a => 'a
   818 => real.  Class real_inner is a subclass of real_normed_vector from
   819 theory RealVector.
   820 
   821 * Theory Library/Product_Vector provides instances for the product
   822 type 'a * 'b of several classes from RealVector and Inner_Product.
   823 Definitions of addition, subtraction, scalar multiplication, norms,
   824 and inner products are included.
   825 
   826 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   827 addition to the field operations, numerals and case syntax are also
   828 supported.
   829 
   830 * Theory Library/Diagonalize provides constructive version of Cantor's
   831 first diagonalization argument.
   832 
   833 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   834 zlcm (for int); carried together from various gcd/lcm developements in
   835 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   836 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   837 may recover tupled syntax as follows:
   838 
   839     hide (open) const gcd
   840     abbreviation gcd where
   841       "gcd == (%(a, b). GCD.gcd a b)"
   842     notation (output)
   843       GCD.gcd ("gcd '(_, _')")
   844 
   845 The same works for lcm, zgcd, zlcm.
   846 
   847 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   848 instantiations for algebraic structures.  Removed some duplicate
   849 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   850 
   851 * ML antiquotation @{code} takes a constant as argument and generates
   852 corresponding code in background and inserts name of the corresponding
   853 resulting ML value/function/datatype constructor binding in place.
   854 All occurrences of @{code} with a single ML block are generated
   855 simultaneously.  Provides a generic and safe interface for
   856 instrumentalizing code generation.  See
   857 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   858 In future you ought to refrain from ad-hoc compiling generated SML
   859 code on the ML toplevel.  Note that (for technical reasons) @{code}
   860 cannot refer to constants for which user-defined serializations are
   861 set.  Refer to the corresponding ML counterpart directly in that
   862 cases.
   863 
   864 * Command 'rep_datatype': instead of theorem names the command now
   865 takes a list of terms denoting the constructors of the type to be
   866 represented as datatype.  The characteristic theorems have to be
   867 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   868 have disappeared in favour of existing ones:
   869 
   870     unit_induct                 ~> unit.induct
   871     prod_induct                 ~> prod.induct
   872     sum_induct                  ~> sum.induct
   873     Suc_Suc_eq                  ~> nat.inject
   874     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   875 
   876 
   877 *** HOL-Algebra ***
   878 
   879 * New locales for orders and lattices where the equivalence relation
   880 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   881 locales use a record structure with field eq for the equivalence.
   882 
   883 * New theory of factorial domains.
   884 
   885 * Units_l_inv and Units_r_inv are now simp rules by default.
   886 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   887 and/or r_inv will now also require deletion of these lemmas.
   888 
   889 * Renamed the following theorems, INCOMPATIBILITY:
   890 
   891 UpperD ~> Upper_memD
   892 LowerD ~> Lower_memD
   893 least_carrier ~> least_closed
   894 greatest_carrier ~> greatest_closed
   895 greatest_Lower_above ~> greatest_Lower_below
   896 one_zero ~> carrier_one_zero
   897 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   898 
   899 
   900 *** HOL-Nominal ***
   901 
   902 * Nominal datatypes can now contain type-variables.
   903 
   904 * Commands 'nominal_inductive' and 'equivariance' work with local
   905 theory targets.
   906 
   907 * Nominal primrec can now works with local theory targets and its
   908 specification syntax now conforms to the general format as seen in
   909 'inductive' etc.
   910 
   911 * Method "perm_simp" honours the standard simplifier attributes
   912 (no_asm), (no_asm_use) etc.
   913 
   914 * The new predicate #* is defined like freshness, except that on the
   915 left hand side can be a set or list of atoms.
   916 
   917 * Experimental command 'nominal_inductive2' derives strong induction
   918 principles for inductive definitions.  In contrast to
   919 'nominal_inductive', which can only deal with a fixed number of
   920 binders, it can deal with arbitrary expressions standing for sets of
   921 atoms to be avoided.  The only inductive definition we have at the
   922 moment that needs this generalisation is the typing rule for Lets in
   923 the algorithm W:
   924 
   925  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
   926  -----------------------------------------------------------------
   927          Gamma |- Let x be t1 in t2 : T2
   928 
   929 In this rule one wants to avoid all the binders that are introduced by
   930 "close Gamma T1".  We are looking for other examples where this
   931 feature might be useful.  Please let us know.
   932 
   933 
   934 *** HOLCF ***
   935 
   936 * Reimplemented the simplification procedure for proving continuity
   937 subgoals.  The new simproc is extensible; users can declare additional
   938 continuity introduction rules with the attribute [cont2cont].
   939 
   940 * The continuity simproc now uses a different introduction rule for
   941 solving continuity subgoals on terms with lambda abstractions.  In
   942 some rare cases the new simproc may fail to solve subgoals that the
   943 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
   944 Potential INCOMPATIBILITY.
   945 
   946 * Command 'fixrec': specification syntax now conforms to the general
   947 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
   948 examples.  INCOMPATIBILITY.
   949 
   950 
   951 *** ZF ***
   952 
   953 * Proof of Zorn's Lemma for partial orders.
   954 
   955 
   956 *** ML ***
   957 
   958 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
   959 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
   960 depends on multithreading, so timouts will not work before Poly/ML
   961 5.2.1!
   962 
   963 * High-level support for concurrent ML programming, see
   964 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
   965 particularly convenient to organize independent functional
   966 computations.  The concept of "synchronized variables" provides a
   967 higher-order interface for components with shared state, avoiding the
   968 delicate details of mutexes and condition variables.  (Requires
   969 Poly/ML 5.2.1 or later.)
   970 
   971 * ML bindings produced via Isar commands are stored within the Isar
   972 context (theory or proof).  Consequently, commands like 'use' and 'ML'
   973 become thread-safe and work with undo as expected (concerning
   974 top-level bindings, not side-effects on global references).
   975 INCOMPATIBILITY, need to provide proper Isar context when invoking the
   976 compiler at runtime; really global bindings need to be given outside a
   977 theory.  (Requires Poly/ML 5.2 or later.)
   978 
   979 * Command 'ML_prf' is analogous to 'ML' but works within a proof
   980 context.  Top-level ML bindings are stored within the proof context in
   981 a purely sequential fashion, disregarding the nested proof structure.
   982 ML bindings introduced by 'ML_prf' are discarded at the end of the
   983 proof.  (Requires Poly/ML 5.2 or later.)
   984 
   985 * Simplified ML attribute and method setup, cf. functions Attrib.setup
   986 and Method.setup, as well as Isar commands 'attribute_setup' and
   987 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
   988 existing code accordingly, or use plain 'setup' together with old
   989 Method.add_method.
   990 
   991 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
   992 to 'a -> thm, while results are always tagged with an authentic oracle
   993 name.  The Isar command 'oracle' is now polymorphic, no argument type
   994 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
   995 accordingly.  Note that extra performance may be gained by producing
   996 the cterm carefully, avoiding slow Thm.cterm_of.
   997 
   998 * Simplified interface for defining document antiquotations via
   999 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1000 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1001 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1002 examples.
  1003 
  1004 * More systematic treatment of long names, abstract name bindings, and
  1005 name space operations.  Basic operations on qualified names have been
  1006 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1007 Long_Name.append.  Old type bstring has been mostly replaced by
  1008 abstract type binding (see structure Binding), which supports precise
  1009 qualification by packages and local theory targets, as well as proper
  1010 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1011 bstring values into Binding.name, or better pass through abstract
  1012 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1013 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1014 
  1015 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1016 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1017 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1018 
  1019 * Disposed old type and term read functions (Sign.read_def_typ,
  1020 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1021 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1022 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1023 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1024 resort for legacy applications.
  1025 
  1026 * Disposed old declarations, tactics, tactic combinators that refer to
  1027 the simpset or claset of an implicit theory (such as Addsimps,
  1028 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1029 embedded ML text, or local_simpset_of with a proper context passed as
  1030 explicit runtime argument.
  1031 
  1032 * Rules and tactics that read instantiations (read_instantiate,
  1033 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1034 context, which is required for parsing and type-checking.  Moreover,
  1035 the variables are specified as plain indexnames, not string encodings
  1036 thereof.  INCOMPATIBILITY.
  1037 
  1038 * Generic Toplevel.add_hook interface allows to analyze the result of
  1039 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1040 for theorem dependency output of transactions resulting in a new
  1041 theory state.
  1042 
  1043 * ML antiquotations: block-structured compilation context indicated by
  1044 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1045 
  1046   @{binding name}                         - basic name binding
  1047   @{let ?pat = term}                      - term abbreviation (HO matching)
  1048   @{note name = fact}                     - fact abbreviation
  1049   @{thm fact}                             - singleton fact (with attributes)
  1050   @{thms fact}                            - general fact (with attributes)
  1051   @{lemma prop by method}                 - singleton goal
  1052   @{lemma prop by meth1 meth2}            - singleton goal
  1053   @{lemma prop1 ... propN by method}      - general goal
  1054   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1055   @{lemma (open) ...}                     - open derivation
  1056 
  1057 
  1058 *** System ***
  1059 
  1060 * The Isabelle "emacs" tool provides a specific interface to invoke
  1061 Proof General / Emacs, with more explicit failure if that is not
  1062 installed (the old isabelle-interface script silently falls back on
  1063 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1064 installation location of the Proof General distribution.
  1065 
  1066 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1067 the Isabelle process into a JVM/Scala application.  See
  1068 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1069 process wrapper has been discontinued.)
  1070 
  1071 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1072 
  1073 * Various status messages (with exact source position information) are
  1074 emitted, if proper markup print mode is enabled.  This allows
  1075 user-interface components to provide detailed feedback on internal
  1076 prover operations.
  1077 
  1078 
  1079 
  1080 New in Isabelle2008 (June 2008)
  1081 -------------------------------
  1082 
  1083 *** General ***
  1084 
  1085 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1086 and updated, with formally checked references as hyperlinks.
  1087 
  1088 * Theory loader: use_thy (and similar operations) no longer set the
  1089 implicit ML context, which was occasionally hard to predict and in
  1090 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1091 provides a proper context already.
  1092 
  1093 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1094 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1095 'use' within a theory file will do the job.
  1096 
  1097 * Name space merge now observes canonical order, i.e. the second space
  1098 is inserted into the first one, while existing entries in the first
  1099 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1100 swap theory imports.
  1101 
  1102 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1103 INCOMPATIBILITY in identifier syntax etc.
  1104 
  1105 * Outer syntax: string tokens no longer admit escaped white space,
  1106 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1107 white space without escapes.
  1108 
  1109 * Outer syntax: string tokens may contain arbitrary character codes
  1110 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1111 "foo_bar".
  1112 
  1113 
  1114 *** Pure ***
  1115 
  1116 * Context-dependent token translations.  Default setup reverts locally
  1117 fixed variables, and adds hilite markup for undeclared frees.
  1118 
  1119 * Unused theorems can be found using the new command 'unused_thms'.
  1120 There are three ways of invoking it:
  1121 
  1122 (1) unused_thms
  1123      Only finds unused theorems in the current theory.
  1124 
  1125 (2) unused_thms thy_1 ... thy_n -
  1126      Finds unused theorems in the current theory and all of its ancestors,
  1127      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1128 
  1129 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1130      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1131      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1132      their ancestors.
  1133 
  1134 In order to increase the readability of the list produced by
  1135 unused_thms, theorems that have been created by a particular instance
  1136 of a theory command such as 'inductive' or 'function' are considered
  1137 to belong to the same "group", meaning that if at least one theorem in
  1138 this group is used, the other theorems in the same group are no longer
  1139 reported as unused.  Moreover, if all theorems in the group are
  1140 unused, only one theorem in the group is displayed.
  1141 
  1142 Note that proof objects have to be switched on in order for
  1143 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1144 usually the case when using Proof General with the default settings).
  1145 
  1146 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1147 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1148 duplicate fact bindings, or even accidental fact duplications.  Note
  1149 that tools may maintain dynamically scoped facts systematically, using
  1150 PureThy.add_thms_dynamic.
  1151 
  1152 * Command 'hide' now allows to hide from "fact" name space as well.
  1153 
  1154 * Eliminated destructive theorem database, simpset, claset, and
  1155 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1156 update of theories within ML code.
  1157 
  1158 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1159 INCOMPATIBILITY, object-logics depending on former Pure require
  1160 additional setup PureThy.old_appl_syntax_setup; object-logics
  1161 depending on former CPure need to refer to Pure.
  1162 
  1163 * Commands 'use' and 'ML' are now purely functional, operating on
  1164 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1165 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1166 INCOMPATIBILITY.
  1167 
  1168 * Command 'setup': discontinued implicit version with ML reference.
  1169 
  1170 * Instantiation target allows for simultaneous specification of class
  1171 instance operations together with an instantiation proof.
  1172 Type-checking phase allows to refer to class operations uniformly.
  1173 See src/HOL/Complex/Complex.thy for an Isar example and
  1174 src/HOL/Library/Eval.thy for an ML example.
  1175 
  1176 * Indexing of literal facts: be more serious about including only
  1177 facts from the visible specification/proof context, but not the
  1178 background context (locale etc.).  Affects `prop` notation and method
  1179 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1180 situations.
  1181 
  1182 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1183 "(open)" option, which used to expose internal bound variables to the
  1184 proof text.
  1185 
  1186 * Isar statements: removed obsolete case "rule_context".
  1187 INCOMPATIBILITY, better use explicit fixes/assumes.
  1188 
  1189 * Locale proofs: default proof step now includes 'unfold_locales';
  1190 hence 'proof' without argument may be used to unfold locale
  1191 predicates.
  1192 
  1193 
  1194 *** Document preparation ***
  1195 
  1196 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1197 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1198 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1199 spot); renamed link color from "darkblue" to "linkcolor" (default
  1200 value unchanged, can be redefined via \definecolor); no longer sets
  1201 "a4paper" option (unnecessary or even intrusive).
  1202 
  1203 * Antiquotation @{lemma A method} proves proposition A by the given
  1204 method (either a method name or a method name plus (optional) method
  1205 arguments in parentheses) and prints A just like @{prop A}.
  1206 
  1207 
  1208 *** HOL ***
  1209 
  1210 * New primrec package.  Specification syntax conforms in style to
  1211 definition/function/....  No separate induction rule is provided.  The
  1212 "primrec" command distinguishes old-style and new-style specifications
  1213 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1214 When adjusting theories, beware: constants stemming from new-style
  1215 primrec specifications have authentic syntax.
  1216 
  1217 * Metis prover is now an order of magnitude faster, and also works
  1218 with multithreading.
  1219 
  1220 * Metis: the maximum number of clauses that can be produced from a
  1221 theorem is now given by the attribute max_clauses.  Theorems that
  1222 exceed this number are ignored, with a warning printed.
  1223 
  1224 * Sledgehammer no longer produces structured proofs by default. To
  1225 enable, declare [[sledgehammer_full = true]].  Attributes
  1226 reconstruction_modulus, reconstruction_sorts renamed
  1227 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1228 
  1229 * Method "induct_scheme" derives user-specified induction rules
  1230 from well-founded induction and completeness of patterns. This factors
  1231 out some operations that are done internally by the function package
  1232 and makes them available separately.  See
  1233 src/HOL/ex/Induction_Scheme.thy for examples.
  1234 
  1235 * More flexible generation of measure functions for termination
  1236 proofs: Measure functions can be declared by proving a rule of the
  1237 form "is_measure f" and giving it the [measure_function] attribute.
  1238 The "is_measure" predicate is logically meaningless (always true), and
  1239 just guides the heuristic.  To find suitable measure functions, the
  1240 termination prover sets up the goal "is_measure ?f" of the appropriate
  1241 type and generates all solutions by prolog-style backwards proof using
  1242 the declared rules.
  1243 
  1244 This setup also deals with rules like 
  1245 
  1246   "is_measure f ==> is_measure (list_size f)"
  1247 
  1248 which accommodates nested datatypes that recurse through lists.
  1249 Similar rules are predeclared for products and option types.
  1250 
  1251 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1252 
  1253   INCOMPATIBILITIES:
  1254 
  1255   - Definitions of overloaded constants on sets have to be replaced by
  1256     definitions on => and bool.
  1257 
  1258   - Some definitions of overloaded operators on sets can now be proved
  1259     using the definitions of the operators on => and bool.  Therefore,
  1260     the following theorems have been renamed:
  1261 
  1262       subset_def   -> subset_eq
  1263       psubset_def  -> psubset_eq
  1264       set_diff_def -> set_diff_eq
  1265       Compl_def    -> Compl_eq
  1266       Sup_set_def  -> Sup_set_eq
  1267       Inf_set_def  -> Inf_set_eq
  1268       sup_set_def  -> sup_set_eq
  1269       inf_set_def  -> inf_set_eq
  1270 
  1271   - Due to the incompleteness of the HO unification algorithm, some
  1272     rules such as subst may require manual instantiation, if some of
  1273     the unknowns in the rule is a set.
  1274 
  1275   - Higher order unification and forward proofs:
  1276     The proof pattern
  1277 
  1278       have "P (S::'a set)" <...>
  1279       then have "EX S. P S" ..
  1280 
  1281     no longer works (due to the incompleteness of the HO unification
  1282     algorithm) and must be replaced by the pattern
  1283 
  1284       have "EX S. P S"
  1285       proof
  1286         show "P S" <...>
  1287       qed
  1288 
  1289   - Calculational reasoning with subst (or similar rules):
  1290     The proof pattern
  1291 
  1292       have "P (S::'a set)" <...>
  1293       also have "S = T" <...>
  1294       finally have "P T" .
  1295 
  1296     no longer works (for similar reasons as the previous example) and
  1297     must be replaced by something like
  1298 
  1299       have "P (S::'a set)" <...>
  1300       moreover have "S = T" <...>
  1301       ultimately have "P T" by simp
  1302 
  1303   - Tactics or packages written in ML code:
  1304     Code performing pattern matching on types via
  1305 
  1306       Type ("set", [T]) => ...
  1307 
  1308     must be rewritten. Moreover, functions like strip_type or
  1309     binder_types no longer return the right value when applied to a
  1310     type of the form
  1311 
  1312       T1 => ... => Tn => U => bool
  1313 
  1314     rather than
  1315 
  1316       T1 => ... => Tn => U set
  1317 
  1318 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1319 Wellfounded_Relations to theory Wellfounded.
  1320 
  1321 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1322 
  1323 * Class finite no longer treats UNIV as class parameter.  Use class
  1324 enum from theory Library/Enum instead to achieve a similar effect.
  1325 INCOMPATIBILITY.
  1326 
  1327 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1328 and "Cons".  INCOMPATIBILITY.
  1329 
  1330 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1331 Potential INCOMPATIBILITY.
  1332 
  1333 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1334 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1335 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1336 
  1337 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1338 the same name in theory Orderings:
  1339 
  1340   less_trans
  1341   less_linear
  1342   le_imp_less_or_eq
  1343   le_less_trans
  1344   less_le_trans
  1345   less_not_sym
  1346   less_asym
  1347 
  1348 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1349 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1350 and different variable names.
  1351 
  1352 * Library/Option_ord.thy: Canonical order on option type.
  1353 
  1354 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1355 finite maps.
  1356 
  1357 * Library/Countable.thy: Type class for countable types.
  1358 
  1359 * Theory Int: The representation of numerals has changed.  The infix
  1360 operator BIT and the bit datatype with constructors B0 and B1 have
  1361 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1362 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1363 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1364 accordingly.
  1365 
  1366 * Theory Nat: definition of <= and < on natural numbers no longer
  1367 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1368 le_def and less_def have disappeared.  Consider lemmas not_less
  1369 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1370 
  1371 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1372 (whose purpose mainly is for various fold_set functionals) have been
  1373 abandoned in favor of the existing algebraic classes
  1374 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1375 lower_semilattice (resp. upper_semilattice) and linorder.
  1376 INCOMPATIBILITY.
  1377 
  1378 * Theory Transitive_Closure: induct and cases rules now declare proper
  1379 case_names ("base" and "step").  INCOMPATIBILITY.
  1380 
  1381 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1382 lattices.  The form set-specific version is available as
  1383 Inductive.lfp_ordinal_induct_set.
  1384 
  1385 * Renamed theorems "power.simps" to "power_int.simps".
  1386 INCOMPATIBILITY.
  1387 
  1388 * Class semiring_div provides basic abstract properties of semirings
  1389 with division and modulo operations.  Subsumes former class dvd_mod.
  1390 
  1391 * Merged theories IntDef, Numeral and IntArith into unified theory
  1392 Int.  INCOMPATIBILITY.
  1393 
  1394 * Theory Library/Code_Index: type "index" now represents natural
  1395 numbers rather than integers.  INCOMPATIBILITY.
  1396 
  1397 * New class "uminus" with operation "uminus" (split of from class
  1398 "minus" which now only has operation "minus", binary).
  1399 INCOMPATIBILITY.
  1400 
  1401 * Constants "card", "internal_split", "option_map" now with authentic
  1402 syntax.  INCOMPATIBILITY.
  1403 
  1404 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1405 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1406 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1407 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1408 Sup_set_def, le_def, less_def, option_map_def now with object
  1409 equality.  INCOMPATIBILITY.
  1410 
  1411 * Records. Removed K_record, and replaced it by pure lambda term
  1412 %x. c. The simplifier setup is now more robust against eta expansion.
  1413 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1414 
  1415 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1416 
  1417 * Library/ListVector: new theory of arithmetic vector operations.
  1418 
  1419 * Library/Order_Relation: new theory of various orderings as sets of
  1420 pairs.  Defines preorders, partial orders, linear orders and
  1421 well-orders on sets and on types.
  1422 
  1423 
  1424 *** ZF ***
  1425 
  1426 * Renamed some theories to allow to loading both ZF and HOL in the
  1427 same session:
  1428 
  1429   Datatype  -> Datatype_ZF
  1430   Inductive -> Inductive_ZF
  1431   Int       -> Int_ZF
  1432   IntDiv    -> IntDiv_ZF
  1433   Nat       -> Nat_ZF
  1434   List      -> List_ZF
  1435   Main      -> Main_ZF
  1436 
  1437 INCOMPATIBILITY: ZF theories that import individual theories below
  1438 Main might need to be adapted.  Regular theory Main is still
  1439 available, as trivial extension of Main_ZF.
  1440 
  1441 
  1442 *** ML ***
  1443 
  1444 * ML within Isar: antiquotation @{const name} or @{const
  1445 name(typargs)} produces statically-checked Const term.
  1446 
  1447 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1448 (of the same name).  Removed obsolete print command.
  1449 
  1450 * Removed obsolete "use_legacy_bindings" function.
  1451 
  1452 * The ``print mode'' is now a thread-local value derived from a global
  1453 template (the former print_mode reference), thus access becomes
  1454 non-critical.  The global print_mode reference is for session
  1455 management only; user-code should use print_mode_value,
  1456 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1457 
  1458 * Functions system/system_out provide a robust way to invoke external
  1459 shell commands, with propagation of interrupts (requires Poly/ML
  1460 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1461 
  1462 
  1463 *** System ***
  1464 
  1465 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1466 in accordance with Proof General 3.7, which prefers GNU emacs.
  1467 
  1468 * isatool tty runs Isabelle process with plain tty interaction;
  1469 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1470 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1471 
  1472 * isatool browser now works with Cygwin as well, using general
  1473 "javapath" function defined in Isabelle process environment.
  1474 
  1475 * YXML notation provides a simple and efficient alternative to
  1476 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1477 isatool yxml as described in the Isabelle system manual.
  1478 
  1479 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1480 provides general wrapper for managing an Isabelle process in a robust
  1481 fashion, with ``cooked'' output from stdin/stderr.
  1482 
  1483 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1484 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1485 
  1486 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1487 way of changing the user's settings is via
  1488 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1489 script.
  1490 
  1491 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1492 cores of the underlying machine, which is a good starting point for
  1493 optimal performance tuning.  The corresponding usedir option -M allows
  1494 "max" as an alias for "0".  WARNING: does not work on certain versions
  1495 of Mac OS (with Poly/ML 5.1).
  1496 
  1497 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1498 adverse effect of Isabelle flooding interactive front-ends (notably
  1499 ProofGeneral / XEmacs).
  1500 
  1501 
  1502 
  1503 New in Isabelle2007 (November 2007)
  1504 -----------------------------------
  1505 
  1506 *** General ***
  1507 
  1508 * More uniform information about legacy features, notably a
  1509 warning/error of "Legacy feature: ...", depending on the state of the
  1510 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1511 legacy features will disappear eventually.
  1512 
  1513 * Theory syntax: the header format ``theory A = B + C:'' has been
  1514 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1515 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1516 
  1517 * Theory syntax: the old non-Isar theory file format has been
  1518 discontinued altogether.  Note that ML proof scripts may still be used
  1519 with Isar theories; migration is usually quite simple with the ML
  1520 function use_legacy_bindings.  INCOMPATIBILITY.
  1521 
  1522 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1523 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1524 quotes.
  1525 
  1526 * Theory loader: be more serious about observing the static theory
  1527 header specifications (including optional directories), but not the
  1528 accidental file locations of previously successful loads.  The strict
  1529 update policy of former update_thy is now already performed by
  1530 use_thy, so the former has been removed; use_thys updates several
  1531 theories simultaneously, just as 'imports' within a theory header
  1532 specification, but without merging the results.  Potential
  1533 INCOMPATIBILITY: may need to refine theory headers and commands
  1534 ROOT.ML which depend on load order.
  1535 
  1536 * Theory loader: optional support for content-based file
  1537 identification, instead of the traditional scheme of full physical
  1538 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1539 (cf. the system manual).  The new scheme allows to work with
  1540 non-finished theories in persistent session images, such that source
  1541 files may be moved later on without requiring reloads.
  1542 
  1543 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1544 file (with the same base name as the theory) are considered a legacy
  1545 feature, which will disappear eventually. Even now, the theory loader
  1546 no longer maintains dependencies on such files.
  1547 
  1548 * Syntax: the scope for resolving ambiguities via type-inference is
  1549 now limited to individual terms, instead of whole simultaneous
  1550 specifications as before. This greatly reduces the complexity of the
  1551 syntax module and improves flexibility by separating parsing and
  1552 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1553 'fixes' etc.) are required in rare situations.
  1554 
  1555 * Syntax: constants introduced by new-style packages ('definition',
  1556 'abbreviation' etc.) are passed through the syntax module in
  1557 ``authentic mode''. This means that associated mixfix annotations
  1558 really stick to such constants, independently of potential name space
  1559 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1560 trees are represented slightly differently, may need to adapt syntax
  1561 translations accordingly. Use CONST marker in 'translations' and
  1562 @{const_syntax} antiquotation in 'parse_translation' etc.
  1563 
  1564 * Legacy goal package: reduced interface to the bare minimum required
  1565 to keep existing proof scripts running.  Most other user-level
  1566 functions are now part of the OldGoals structure, which is *not* open
  1567 by default (consider isatool expandshort before open OldGoals).
  1568 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1569 these tend to cause confusion about the actual goal (!) context being
  1570 used here, which is not necessarily the same as the_context().
  1571 
  1572 * Command 'find_theorems': supports "*" wild-card in "name:"
  1573 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1574 support a specific search form (see ProofGeneral/CHANGES).
  1575 
  1576 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1577 by default, which means that "prems" (and also "fixed variables") are
  1578 suppressed from proof state output.  Note that the ProofGeneral
  1579 settings mechanism allows to change and save options persistently, but
  1580 older versions of Isabelle will fail to start up if a negative prems
  1581 limit is imposed.
  1582 
  1583 * Local theory targets may be specified by non-nested blocks of
  1584 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1585 contain definitions, theorems etc., including any derived mechanism
  1586 that has been implemented on top of these primitives.  This concept
  1587 generalizes the existing ``theorem (in ...)'' towards more versatility
  1588 and scalability.
  1589 
  1590 * Proof General interface: proper undo of final 'end' command;
  1591 discontinued Isabelle/classic mode (ML proof scripts).
  1592 
  1593 
  1594 *** Document preparation ***
  1595 
  1596 * Added antiquotation @{theory name} which prints the given name,
  1597 after checking that it refers to a valid ancestor theory in the
  1598 current context.
  1599 
  1600 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1601 check the given source text as ML type/structure, printing verbatim.
  1602 
  1603 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1604 "c args == rhs" given in the current context.  (Any number of
  1605 arguments may be given on the LHS.)
  1606 
  1607 
  1608 *** Pure ***
  1609 
  1610 * The 'class' package offers a combination of axclass and locale to
  1611 achieve Haskell-like type classes in Isabelle.  Definitions and
  1612 theorems within a class context produce both relative results (with
  1613 implicit parameters according to the locale context), and polymorphic
  1614 constants with qualified polymorphism (according to the class
  1615 context).  Within the body context of a 'class' target, a separate
  1616 syntax layer ("user space type system") takes care of converting
  1617 between global polymorphic consts and internal locale representation.
  1618 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1619 "isatool doc classes" provides a tutorial.
  1620 
  1621 * Generic code generator framework allows to generate executable
  1622 code for ML and Haskell (including Isabelle classes).  A short usage
  1623 sketch:
  1624 
  1625     internal compilation:
  1626         export_code <list of constants (term syntax)> in SML
  1627     writing SML code to a file:
  1628         export_code <list of constants (term syntax)> in SML <filename>
  1629     writing OCaml code to a file:
  1630         export_code <list of constants (term syntax)> in OCaml <filename>
  1631     writing Haskell code to a bunch of files:
  1632         export_code <list of constants (term syntax)> in Haskell <filename>
  1633 
  1634     evaluating closed propositions to True/False using code generation:
  1635         method ``eval''
  1636 
  1637 Reasonable default setup of framework in HOL.
  1638 
  1639 Theorem attributs for selecting and transforming function equations theorems:
  1640 
  1641     [code fun]:        select a theorem as function equation for a specific constant
  1642     [code fun del]:    deselect a theorem as function equation for a specific constant
  1643     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1644     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1645 
  1646 User-defined serializations (target in {SML, OCaml, Haskell}):
  1647 
  1648     code_const <and-list of constants (term syntax)>
  1649       {(target) <and-list of const target syntax>}+
  1650 
  1651     code_type <and-list of type constructors>
  1652       {(target) <and-list of type target syntax>}+
  1653 
  1654     code_instance <and-list of instances>
  1655       {(target)}+
  1656         where instance ::= <type constructor> :: <class>
  1657 
  1658     code_class <and_list of classes>
  1659       {(target) <and-list of class target syntax>}+
  1660         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1661 
  1662 code_instance and code_class only are effective to target Haskell.
  1663 
  1664 For example usage see src/HOL/ex/Codegenerator.thy and
  1665 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1666 generation from Isabelle/HOL theories is available via "isatool doc
  1667 codegen".
  1668 
  1669 * Code generator: consts in 'consts_code' Isar commands are now
  1670 referred to by usual term syntax (including optional type
  1671 annotations).
  1672 
  1673 * Command 'no_translations' removes translation rules from theory
  1674 syntax.
  1675 
  1676 * Overloaded definitions are now actually checked for acyclic
  1677 dependencies.  The overloading scheme is slightly more general than
  1678 that of Haskell98, although Isabelle does not demand an exact
  1679 correspondence to type class and instance declarations.
  1680 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1681 exotic versions of overloading -- at the discretion of the user!
  1682 
  1683 Polymorphic constants are represented via type arguments, i.e. the
  1684 instantiation that matches an instance against the most general
  1685 declaration given in the signature.  For example, with the declaration
  1686 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1687 as c(nat).  Overloading is essentially simultaneous structural
  1688 recursion over such type arguments.  Incomplete specification patterns
  1689 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1690 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1691 Command 'print_theory' outputs the normalized system of recursive
  1692 equations, see section "definitions".
  1693 
  1694 * Configuration options are maintained within the theory or proof
  1695 context (with name and type bool/int/string), providing a very simple
  1696 interface to a poor-man's version of general context data.  Tools may
  1697 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1698 these values using Config.get etc.  Users may change options via an
  1699 associated attribute of the same name.  This form of context
  1700 declaration works particularly well with commands 'declare' or
  1701 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1702 very easy to avoid global references, which would not observe Isar
  1703 toplevel undo/redo and fail to work with multithreading.
  1704 
  1705 Various global ML references of Pure and HOL have been turned into
  1706 configuration options:
  1707 
  1708   Unify.search_bound		unify_search_bound
  1709   Unify.trace_bound		unify_trace_bound
  1710   Unify.trace_simp		unify_trace_simp
  1711   Unify.trace_types		unify_trace_types
  1712   Simplifier.simp_depth_limit	simp_depth_limit
  1713   Blast.depth_limit		blast_depth_limit
  1714   DatatypeProp.dtK		datatype_distinctness_limit
  1715   fast_arith_neq_limit  	fast_arith_neq_limit
  1716   fast_arith_split_limit	fast_arith_split_limit
  1717 
  1718 * Named collections of theorems may be easily installed as context
  1719 data using the functor NamedThmsFun (see also
  1720 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1721 attributes; there is also a toplevel print command.  This facility is
  1722 just a common case of general context data, which is the preferred way
  1723 for anything more complex than just a list of facts in canonical
  1724 order.
  1725 
  1726 * Isar: command 'declaration' augments a local theory by generic
  1727 declaration functions written in ML.  This enables arbitrary content
  1728 being added to the context, depending on a morphism that tells the
  1729 difference of the original declaration context wrt. the application
  1730 context encountered later on.
  1731 
  1732 * Isar: proper interfaces for simplification procedures.  Command
  1733 'simproc_setup' declares named simprocs (with match patterns, and body
  1734 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1735 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1736 
  1737 * Isar: an extra pair of brackets around attribute declarations
  1738 abbreviates a theorem reference involving an internal dummy fact,
  1739 which will be ignored later --- only the effect of the attribute on
  1740 the background context will persist.  This form of in-place
  1741 declarations is particularly useful with commands like 'declare' and
  1742 'using', for example ``have A using [[simproc a]] by simp''.
  1743 
  1744 * Isar: method "assumption" (and implicit closing of subproofs) now
  1745 takes simple non-atomic goal assumptions into account: after applying
  1746 an assumption as a rule the resulting subgoals are solved by atomic
  1747 assumption steps.  This is particularly useful to finish 'obtain'
  1748 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1749 without referring to the original premise "!!x. P x ==> thesis" in the
  1750 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1751 more permissive.
  1752 
  1753 * Isar: implicit use of prems from the Isar proof context is
  1754 considered a legacy feature.  Common applications like ``have A .''
  1755 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1756 referencing facts explicitly here improves readability and
  1757 maintainability of proof texts.
  1758 
  1759 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1760 the obtained context from the course of reasoning!  For example:
  1761 
  1762   assume "EX x y. A x & B y"   -- "any previous fact"
  1763   then guess x and y by clarify
  1764 
  1765 This technique is potentially adventurous, depending on the facts and
  1766 proof tools being involved here.
  1767 
  1768 * Isar: known facts from the proof context may be specified as literal
  1769 propositions, using ASCII back-quote syntax.  This works wherever
  1770 named facts used to be allowed so far, in proof commands, proof
  1771 methods, attributes etc.  Literal facts are retrieved from the context
  1772 according to unification of type and term parameters.  For example,
  1773 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1774 theorems in the current context, then these are valid literal facts:
  1775 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1776 
  1777 There is also a proof method "fact" which does the same composition
  1778 for explicit goal states, e.g. the following proof texts coincide with
  1779 certain special cases of literal facts:
  1780 
  1781   have "A" by fact                 ==  note `A`
  1782   have "A ==> B" by fact           ==  note `A ==> B`
  1783   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1784   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1785 
  1786 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1787 outer syntax.  Thus symbolic identifiers may be used without
  1788 additional white space in declarations like this: ``assume *: A''.
  1789 
  1790 * Isar: 'print_facts' prints all local facts of the current context,
  1791 both named and unnamed ones.
  1792 
  1793 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1794 
  1795   def x == "t" and y == "u"
  1796 
  1797 * Isar: added command 'unfolding', which is structurally similar to
  1798 'using', but affects both the goal state and facts by unfolding given
  1799 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1800 'unfolded' attribute may be replaced by first-class proof text.
  1801 
  1802 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1803 and command 'unfolding' now all support object-level equalities
  1804 (potentially conditional).  The underlying notion of rewrite rule is
  1805 analogous to the 'rule_format' attribute, but *not* that of the
  1806 Simplifier (which is usually more generous).
  1807 
  1808 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1809 premises of a theorem by n. Useful in conjunction with drule.
  1810 
  1811 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1812 method expression within a sandbox consisting of the first N
  1813 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1814 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1815 simplifies all new goals that emerge from applying rule foo to the
  1816 originally first one.
  1817 
  1818 * Isar: schematic goals are no longer restricted to higher-order
  1819 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1820 expected.
  1821 
  1822 * Isar: the conclusion of a long theorem statement is now either
  1823 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1824 (essentially a disjunction of cases with local parameters and
  1825 assumptions).  The latter allows to express general elimination rules
  1826 adequately; in this notation common elimination rules look like this:
  1827 
  1828   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1829     assumes "EX x. P x"
  1830     obtains x where "P x"
  1831 
  1832   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1833     assumes "A & B"
  1834     obtains A and B
  1835 
  1836   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1837     assumes "A | B"
  1838     obtains
  1839       A
  1840     | B
  1841 
  1842 The subsequent classical rules even refer to the formal "thesis"
  1843 explicitly:
  1844 
  1845   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1846     obtains "~ thesis"
  1847 
  1848   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1849     obtains "thesis ==> something"
  1850 
  1851 The actual proof of an 'obtains' statement is analogous to that of the
  1852 Isar proof element 'obtain', only that there may be several cases.
  1853 Optional case names may be specified in parentheses; these will be
  1854 available both in the present proof and as annotations in the
  1855 resulting rule, for later use with the 'cases' method (cf. attribute
  1856 case_names).
  1857 
  1858 * Isar: the assumptions of a long theorem statement are available as
  1859 "assms" fact in the proof context.  This is more appropriate than the
  1860 (historical) "prems", which refers to all assumptions of the current
  1861 context, including those from the target locale, proof body etc.
  1862 
  1863 * Isar: 'print_statement' prints theorems from the current theory or
  1864 proof context in long statement form, according to the syntax of a
  1865 top-level lemma.
  1866 
  1867 * Isar: 'obtain' takes an optional case name for the local context
  1868 introduction rule (default "that").
  1869 
  1870 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1871 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1872 to occur.
  1873 
  1874 * Pure: syntax "CONST name" produces a fully internalized constant
  1875 according to the current context.  This is particularly useful for
  1876 syntax translations that should refer to internal constant
  1877 representations independently of name spaces.
  1878 
  1879 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1880 instead of "FOO ". This allows multiple binder declarations to coexist
  1881 in the same context.  INCOMPATIBILITY.
  1882 
  1883 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1884 primitive that also works in a locale context (both for constants and
  1885 fixed variables). Type declaration and internal syntactic representation
  1886 of given constants retrieved from the context. Likewise, the
  1887 'no_notation' command allows to remove given syntax annotations from the
  1888 current context.
  1889 
  1890 * Isar/locales: new derived specification elements 'axiomatization',
  1891 'definition', 'abbreviation', which support type-inference, admit
  1892 object-level specifications (equality, equivalence).  See also the
  1893 isar-ref manual.  Examples:
  1894 
  1895   axiomatization
  1896     eq  (infix "===" 50) where
  1897     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1898 
  1899   definition "f x y = x + y + 1"
  1900   definition g where "g x = f x x"
  1901 
  1902   abbreviation
  1903     neq  (infix "=!=" 50) where
  1904     "x =!= y == ~ (x === y)"
  1905 
  1906 These specifications may be also used in a locale context.  Then the
  1907 constants being introduced depend on certain fixed parameters, and the
  1908 constant name is qualified by the locale base name.  An internal
  1909 abbreviation takes care for convenient input and output, making the
  1910 parameters implicit and using the original short name.  See also
  1911 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1912 entities from a monomorphic theory.
  1913 
  1914 Presently, abbreviations are only available 'in' a target locale, but
  1915 not inherited by general import expressions.  Also note that
  1916 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1917 'translations' in common applications.  The "no_abbrevs" print mode
  1918 prevents folding of abbreviations in term output.
  1919 
  1920 Concrete syntax is attached to specified constants in internal form,
  1921 independently of name spaces.  The parse tree representation is
  1922 slightly different -- use 'notation' instead of raw 'syntax', and
  1923 'translations' with explicit "CONST" markup to accommodate this.
  1924 
  1925 * Pure/Isar: unified syntax for new-style specification mechanisms
  1926 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  1927 full type inference and dummy patterns ("_").  For example:
  1928 
  1929   definition "K x _ = x"
  1930 
  1931   inductive conj for A B
  1932   where "A ==> B ==> conj A B"
  1933 
  1934 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  1935 the current context.  Print mode "no_abbrevs" prevents inversion of
  1936 abbreviations on output.
  1937 
  1938 * Isar/locales: improved parameter handling: use of locales "var" and
  1939 "struct" no longer necessary; - parameter renamings are no longer
  1940 required to be injective.  For example, this allows to define
  1941 endomorphisms as locale endom = homom mult mult h.
  1942 
  1943 * Isar/locales: changed the way locales with predicates are defined.
  1944 Instead of accumulating the specification, the imported expression is
  1945 now an interpretation.  INCOMPATIBILITY: different normal form of
  1946 locale expressions.  In particular, in interpretations of locales with
  1947 predicates, goals repesenting already interpreted fragments are not
  1948 removed automatically.  Use methods `intro_locales' and
  1949 `unfold_locales'; see below.
  1950 
  1951 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  1952 provide backward reasoning on locales predicates.  The methods are
  1953 aware of interpretations and discharge corresponding goals.
  1954 `intro_locales' is less aggressive then `unfold_locales' and does not
  1955 unfold predicates to assumptions.
  1956 
  1957 * Isar/locales: the order in which locale fragments are accumulated
  1958 has changed.  This enables to override declarations from fragments due
  1959 to interpretations -- for example, unwanted simp rules.
  1960 
  1961 * Isar/locales: interpretation in theories and proof contexts has been
  1962 extended.  One may now specify (and prove) equations, which are
  1963 unfolded in interpreted theorems.  This is useful for replacing
  1964 defined concepts (constants depending on locale parameters) by
  1965 concepts already existing in the target context.  Example:
  1966 
  1967   interpretation partial_order ["op <= :: [int, int] => bool"]
  1968     where "partial_order.less (op <=) (x::int) y = (x < y)"
  1969 
  1970 Typically, the constant `partial_order.less' is created by a
  1971 definition specification element in the context of locale
  1972 partial_order.
  1973 
  1974 * Method "induct": improved internal context management to support
  1975 local fixes and defines on-the-fly. Thus explicit meta-level
  1976 connectives !!  and ==> are rarely required anymore in inductive goals
  1977 (using object-logic connectives for this purpose has been long
  1978 obsolete anyway). Common proof patterns are explained in
  1979 src/HOL/Induct/Common_Patterns.thy, see also
  1980 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  1981 examples.
  1982 
  1983 * Method "induct": improved handling of simultaneous goals. Instead of
  1984 introducing object-level conjunction, the statement is now split into
  1985 several conclusions, while the corresponding symbolic cases are nested
  1986 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  1987 see src/HOL/Induct/Common_Patterns.thy, for example.
  1988 
  1989 * Method "induct": mutual induction rules are now specified as a list
  1990 of rule sharing the same induction cases. HOL packages usually provide
  1991 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  1992 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  1993 mutual induction rules differently, i.e. like this:
  1994 
  1995   (induct rule: foo_bar.inducts)
  1996   (induct set: foo bar)
  1997   (induct pred: foo bar)
  1998   (induct type: foo bar)
  1999 
  2000 The ML function ProjectRule.projections turns old-style rules into the
  2001 new format.
  2002 
  2003 * Method "coinduct": dual of induction, see
  2004 src/HOL/Library/Coinductive_List.thy for various examples.
  2005 
  2006 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2007 considered a legacy feature.
  2008 
  2009 * Attribute "symmetric" produces result with standardized schematic
  2010 variables (index 0).  Potential INCOMPATIBILITY.
  2011 
  2012 * Simplifier: by default the simplifier trace only shows top level
  2013 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2014 default. Thus there is less danger of being flooded by the trace. The
  2015 trace indicates where parts have been suppressed.
  2016   
  2017 * Provers/classical: removed obsolete classical version of elim_format
  2018 attribute; classical elim/dest rules are now treated uniformly when
  2019 manipulating the claset.
  2020 
  2021 * Provers/classical: stricter checks to ensure that supplied intro,
  2022 dest and elim rules are well-formed; dest and elim rules must have at
  2023 least one premise.
  2024 
  2025 * Provers/classical: attributes dest/elim/intro take an optional
  2026 weight argument for the rule (just as the Pure versions).  Weights are
  2027 ignored by automated tools, but determine the search order of single
  2028 rule steps.
  2029 
  2030 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2031 where the body does not mention the bound variable.  Note that dummy
  2032 patterns implicitly depend on their context of bounds, which makes
  2033 "{_. _}" match any set comprehension as expected.  Potential
  2034 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2035 constant "_idtdummy" in the binding position.
  2036 
  2037 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2038 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2039 for example "A -> B" => "Pi A (%_. B)".
  2040 
  2041 * Pure: 'class_deps' command visualizes the subclass relation, using
  2042 the graph browser tool.
  2043 
  2044 * Pure: 'print_theory' now suppresses certain internal declarations by
  2045 default; use '!' option for full details.
  2046 
  2047 
  2048 *** HOL ***
  2049 
  2050 * Method "metis" proves goals by applying the Metis general-purpose
  2051 resolution prover (see also http://gilith.com/software/metis/).
  2052 Examples are in the directory MetisExamples.  WARNING: the
  2053 Isabelle/HOL-Metis integration does not yet work properly with
  2054 multi-threading.
  2055   
  2056 * Command 'sledgehammer' invokes external automatic theorem provers as
  2057 background processes.  It generates calls to the "metis" method if
  2058 successful. These can be pasted into the proof.  Users do not have to
  2059 wait for the automatic provers to return.  WARNING: does not really
  2060 work with multi-threading.
  2061 
  2062 * New "auto_quickcheck" feature tests outermost goal statements for
  2063 potential counter-examples.  Controlled by ML references
  2064 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2065 5000 milliseconds).  Fails silently if statements is outside of
  2066 executable fragment, or any other codgenerator problem occurs.
  2067 
  2068 * New constant "undefined" with axiom "undefined x = undefined".
  2069 
  2070 * Added class "HOL.eq", allowing for code generation with polymorphic
  2071 equality.
  2072 
  2073 * Some renaming of class constants due to canonical name prefixing in
  2074 the new 'class' package:
  2075 
  2076     HOL.abs ~> HOL.abs_class.abs
  2077     HOL.divide ~> HOL.divide_class.divide
  2078     0 ~> HOL.zero_class.zero
  2079     1 ~> HOL.one_class.one
  2080     op + ~> HOL.plus_class.plus
  2081     op - ~> HOL.minus_class.minus
  2082     uminus ~> HOL.minus_class.uminus
  2083     op * ~> HOL.times_class.times
  2084     op < ~> HOL.ord_class.less
  2085     op <= > HOL.ord_class.less_eq
  2086     Nat.power ~> Power.power_class.power
  2087     Nat.size ~> Nat.size_class.size
  2088     Numeral.number_of ~> Numeral.number_class.number_of
  2089     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2090     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2091     Orderings.min ~> Orderings.ord_class.min
  2092     Orderings.max ~> Orderings.ord_class.max
  2093     Divides.op div ~> Divides.div_class.div
  2094     Divides.op mod ~> Divides.div_class.mod
  2095     Divides.op dvd ~> Divides.div_class.dvd
  2096 
  2097 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2098 
  2099 a) User-defined constants using any of the names "plus", "minus",
  2100 "times", "less" or "less_eq". The standard syntax translations for
  2101 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2102 names.
  2103 
  2104 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2105 INCOMPATIBILITY: use more specific names.
  2106 
  2107 c) Permutative equations (e.g. "a + b = b + a")
  2108 Since the change of names also changes the order of terms, permutative
  2109 rewrite rules may get applied in a different order. Experience shows
  2110 that this is rarely the case (only two adaptions in the whole Isabelle
  2111 distribution).  INCOMPATIBILITY: rewrite proofs
  2112 
  2113 d) ML code directly refering to constant names
  2114 This in general only affects hand-written proof tactics, simprocs and
  2115 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2116 Consider using @{const_name} antiquotation.
  2117 
  2118 * New class "default" with associated constant "default".
  2119 
  2120 * Function "sgn" is now overloaded and available on int, real, complex
  2121 (and other numeric types), using class "sgn".  Two possible defs of
  2122 sgn are given as equational assumptions in the classes sgn_if and
  2123 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2124 INCOMPATIBILITY.
  2125 
  2126 * Locale "partial_order" now unified with class "order" (cf. theory
  2127 Orderings), added parameter "less".  INCOMPATIBILITY.
  2128 
  2129 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2130 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2131 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2132 
  2133 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2134 changed order of proof goals in instance proofs.
  2135 
  2136 * The transitivity reasoner for partial and linear orders is set up
  2137 for classes "order" and "linorder".  Instances of the reasoner are available
  2138 in all contexts importing or interpreting the corresponding locales.
  2139 Method "order" invokes the reasoner separately; the reasoner
  2140 is also integrated with the Simplifier as a solver.  Diagnostic
  2141 command 'print_orders' shows the available instances of the reasoner
  2142 in the current context.
  2143 
  2144 * Localized monotonicity predicate in theory "Orderings"; integrated
  2145 lemmas max_of_mono and min_of_mono with this predicate.
  2146 INCOMPATIBILITY.
  2147 
  2148 * Formulation of theorem "dense" changed slightly due to integration
  2149 with new class dense_linear_order.
  2150 
  2151 * Uniform lattice theory development in HOL.
  2152 
  2153     constants "meet" and "join" now named "inf" and "sup"
  2154     constant "Meet" now named "Inf"
  2155 
  2156     classes "meet_semilorder" and "join_semilorder" now named
  2157       "lower_semilattice" and "upper_semilattice"
  2158     class "lorder" now named "lattice"
  2159     class "comp_lat" now named "complete_lattice"
  2160 
  2161     Instantiation of lattice classes allows explicit definitions
  2162     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2163 
  2164   INCOMPATIBILITY.  Theorem renames:
  2165 
  2166     meet_left_le            ~> inf_le1
  2167     meet_right_le           ~> inf_le2
  2168     join_left_le            ~> sup_ge1
  2169     join_right_le           ~> sup_ge2
  2170     meet_join_le            ~> inf_sup_ord
  2171     le_meetI                ~> le_infI
  2172     join_leI                ~> le_supI
  2173     le_meet                 ~> le_inf_iff
  2174     le_join                 ~> ge_sup_conv
  2175     meet_idempotent         ~> inf_idem
  2176     join_idempotent         ~> sup_idem
  2177     meet_comm               ~> inf_commute
  2178     join_comm               ~> sup_commute
  2179     meet_leI1               ~> le_infI1
  2180     meet_leI2               ~> le_infI2
  2181     le_joinI1               ~> le_supI1
  2182     le_joinI2               ~> le_supI2
  2183     meet_assoc              ~> inf_assoc
  2184     join_assoc              ~> sup_assoc
  2185     meet_left_comm          ~> inf_left_commute
  2186     meet_left_idempotent    ~> inf_left_idem
  2187     join_left_comm          ~> sup_left_commute
  2188     join_left_idempotent    ~> sup_left_idem
  2189     meet_aci                ~> inf_aci
  2190     join_aci                ~> sup_aci
  2191     le_def_meet             ~> le_iff_inf
  2192     le_def_join             ~> le_iff_sup
  2193     join_absorp2            ~> sup_absorb2
  2194     join_absorp1            ~> sup_absorb1
  2195     meet_absorp1            ~> inf_absorb1
  2196     meet_absorp2            ~> inf_absorb2
  2197     meet_join_absorp        ~> inf_sup_absorb
  2198     join_meet_absorp        ~> sup_inf_absorb
  2199     distrib_join_le         ~> distrib_sup_le
  2200     distrib_meet_le         ~> distrib_inf_le
  2201 
  2202     add_meet_distrib_left   ~> add_inf_distrib_left
  2203     add_join_distrib_left   ~> add_sup_distrib_left
  2204     is_join_neg_meet        ~> is_join_neg_inf
  2205     is_meet_neg_join        ~> is_meet_neg_sup
  2206     add_meet_distrib_right  ~> add_inf_distrib_right
  2207     add_join_distrib_right  ~> add_sup_distrib_right
  2208     add_meet_join_distribs  ~> add_sup_inf_distribs
  2209     join_eq_neg_meet        ~> sup_eq_neg_inf
  2210     meet_eq_neg_join        ~> inf_eq_neg_sup
  2211     add_eq_meet_join        ~> add_eq_inf_sup
  2212     meet_0_imp_0            ~> inf_0_imp_0
  2213     join_0_imp_0            ~> sup_0_imp_0
  2214     meet_0_eq_0             ~> inf_0_eq_0
  2215     join_0_eq_0             ~> sup_0_eq_0
  2216     neg_meet_eq_join        ~> neg_inf_eq_sup
  2217     neg_join_eq_meet        ~> neg_sup_eq_inf
  2218     join_eq_if              ~> sup_eq_if
  2219 
  2220     mono_meet               ~> mono_inf
  2221     mono_join               ~> mono_sup
  2222     meet_bool_eq            ~> inf_bool_eq
  2223     join_bool_eq            ~> sup_bool_eq
  2224     meet_fun_eq             ~> inf_fun_eq
  2225     join_fun_eq             ~> sup_fun_eq
  2226     meet_set_eq             ~> inf_set_eq
  2227     join_set_eq             ~> sup_set_eq
  2228     meet1_iff               ~> inf1_iff
  2229     meet2_iff               ~> inf2_iff
  2230     meet1I                  ~> inf1I
  2231     meet2I                  ~> inf2I
  2232     meet1D1                 ~> inf1D1
  2233     meet2D1                 ~> inf2D1
  2234     meet1D2                 ~> inf1D2
  2235     meet2D2                 ~> inf2D2
  2236     meet1E                  ~> inf1E
  2237     meet2E                  ~> inf2E
  2238     join1_iff               ~> sup1_iff
  2239     join2_iff               ~> sup2_iff
  2240     join1I1                 ~> sup1I1
  2241     join2I1                 ~> sup2I1
  2242     join1I1                 ~> sup1I1
  2243     join2I2                 ~> sup1I2
  2244     join1CI                 ~> sup1CI
  2245     join2CI                 ~> sup2CI
  2246     join1E                  ~> sup1E
  2247     join2E                  ~> sup2E
  2248 
  2249     is_meet_Meet            ~> is_meet_Inf
  2250     Meet_bool_def           ~> Inf_bool_def
  2251     Meet_fun_def            ~> Inf_fun_def
  2252     Meet_greatest           ~> Inf_greatest
  2253     Meet_lower              ~> Inf_lower
  2254     Meet_set_def            ~> Inf_set_def
  2255 
  2256     Sup_def                 ~> Sup_Inf
  2257     Sup_bool_eq             ~> Sup_bool_def
  2258     Sup_fun_eq              ~> Sup_fun_def
  2259     Sup_set_eq              ~> Sup_set_def
  2260 
  2261     listsp_meetI            ~> listsp_infI
  2262     listsp_meet_eq          ~> listsp_inf_eq
  2263 
  2264     meet_min                ~> inf_min
  2265     join_max                ~> sup_max
  2266 
  2267 * Added syntactic class "size"; overloaded constant "size" now has
  2268 type "'a::size ==> bool"
  2269 
  2270 * Internal reorganisation of `size' of datatypes: size theorems
  2271 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2272 simplification rules by default!); theorems "prod.size" now named
  2273 "*.size".
  2274 
  2275 * Class "div" now inherits from class "times" rather than "type".
  2276 INCOMPATIBILITY.
  2277 
  2278 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2279 Linorder etc.  have disappeared; operations defined in terms of
  2280 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2281 
  2282 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2283 
  2284 * HOL-Word: New extensive library and type for generic, fixed size
  2285 machine words, with arithemtic, bit-wise, shifting and rotating
  2286 operations, reflection into int, nat, and bool lists, automation for
  2287 linear arithmetic (by automatic reflection into nat or int), including
  2288 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2289 arithmetic type classes, supporting automatic simplification of
  2290 numerals on all operations.
  2291 
  2292 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2293 
  2294 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2295 
  2296 * Code generator library theories:
  2297   - Code_Integer represents HOL integers by big integer literals in target
  2298     languages.
  2299   - Code_Char represents HOL characters by character literals in target
  2300     languages.
  2301   - Code_Char_chr like Code_Char, but also offers treatment of character
  2302     codes; includes Code_Integer.
  2303   - Executable_Set allows to generate code for finite sets using lists.
  2304   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2305     denominator).
  2306   - Executable_Real implements a subset of real numbers, namly those
  2307     representable by rational numbers.
  2308   - Efficient_Nat implements natural numbers by integers, which in general will
  2309     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2310     includes Code_Integer.
  2311   - Code_Index provides an additional datatype index which is mapped to
  2312     target-language built-in integers.
  2313   - Code_Message provides an additional datatype message_string which is isomorphic to
  2314     strings; messages are mapped to target-language strings.
  2315 
  2316 * New package for inductive predicates
  2317 
  2318   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2319 
  2320     inductive
  2321       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2322       for z_1 :: U_1 and ... and z_n :: U_m
  2323     where
  2324       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2325     | ...
  2326 
  2327   with full support for type-inference, rather than
  2328 
  2329     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2330 
  2331     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2332     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2333 
  2334     inductive "s z_1 ... z_m"
  2335     intros
  2336       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2337       ...
  2338 
  2339   For backward compatibility, there is a wrapper allowing inductive
  2340   sets to be defined with the new package via
  2341 
  2342     inductive_set
  2343       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2344       for z_1 :: U_1 and ... and z_n :: U_m
  2345     where
  2346       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2347     | ...
  2348 
  2349   or
  2350 
  2351     inductive_set
  2352       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2353       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2354       for z_1 :: U_1 and ... and z_n :: U_m
  2355     where
  2356       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2357     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2358     | ...
  2359 
  2360   if the additional syntax "p ..." is required.
  2361 
  2362   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2363   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2364 
  2365   INCOMPATIBILITIES:
  2366 
  2367   - Since declaration and definition of inductive sets or predicates
  2368     is no longer separated, abbreviations involving the newly
  2369     introduced sets or predicates must be specified together with the
  2370     introduction rules after the 'where' keyword (see above), rather
  2371     than before the actual inductive definition.
  2372 
  2373   - The variables in induction and elimination rules are now
  2374     quantified in the order of their occurrence in the introduction
  2375     rules, rather than in alphabetical order. Since this may break
  2376     some proofs, these proofs either have to be repaired, e.g. by
  2377     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2378     statements of the form
  2379 
  2380       case (rule_i a_i_1 ... a_i_{k_i})
  2381 
  2382     or the old order of quantification has to be restored by explicitly adding
  2383     meta-level quantifiers in the introduction rules, i.e.
  2384 
  2385       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2386 
  2387   - The format of the elimination rules is now
  2388 
  2389       p z_1 ... z_m x_1 ... x_n ==>
  2390         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2391         ==> ... ==> P
  2392 
  2393     for predicates and
  2394 
  2395       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2396         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2397         ==> ... ==> P
  2398 
  2399     for sets rather than
  2400 
  2401       x : s z_1 ... z_m ==>
  2402         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2403         ==> ... ==> P
  2404 
  2405     This may require terms in goals to be expanded to n-tuples
  2406     (e.g. using case_tac or simplification with the split_paired_all
  2407     rule) before the above elimination rule is applicable.
  2408 
  2409   - The elimination or case analysis rules for (mutually) inductive
  2410     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2411     list of rules "p_1_..._p_k.elims" is no longer available.
  2412 
  2413 * New package "function"/"fun" for general recursive functions,
  2414 supporting mutual and nested recursion, definitions in local contexts,
  2415 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2416 for small examples, and the separate tutorial on the function
  2417 package. The old recdef "package" is still available as before, but
  2418 users are encouraged to use the new package.
  2419 
  2420 * Method "lexicographic_order" automatically synthesizes termination
  2421 relations as lexicographic combinations of size measures. 
  2422 
  2423 * Case-expressions allow arbitrary constructor-patterns (including
  2424 "_") and take their order into account, like in functional
  2425 programming.  Internally, this is translated into nested
  2426 case-expressions; missing cases are added and mapped to the predefined
  2427 constant "undefined". In complicated cases printing may no longer show
  2428 the original input but the internal form. Lambda-abstractions allow
  2429 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2430 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2431 variable.
  2432 
  2433 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2434 is an abbreviation for "of_nat :: nat => int". The simplification
  2435 rules for "of_nat" have been changed to work like "int" did
  2436 previously.  Potential INCOMPATIBILITY:
  2437   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2438   - of_nat_diff and of_nat_mult are no longer default simp rules
  2439 
  2440 * Method "algebra" solves polynomial equations over (semi)rings using
  2441 Groebner bases. The (semi)ring structure is defined by locales and the
  2442 tool setup depends on that generic context. Installing the method for
  2443 a specific type involves instantiating the locale and possibly adding
  2444 declarations for computation on the coefficients.  The method is
  2445 already instantiated for natural numbers and for the axiomatic class
  2446 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2447 CALCULEMUS 2007 for the general principles underlying this
  2448 architecture of context-aware proof-tools.
  2449 
  2450 * Method "ferrack" implements quantifier elimination over
  2451 special-purpose dense linear orders using locales (analogous to
  2452 "algebra"). The method is already installed for class
  2453 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2454 rat, etc.
  2455 
  2456 * Former constant "List.op @" now named "List.append".  Use ML
  2457 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2458 circumvent possible incompatibilities when working on ML level.
  2459 
  2460 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2461 
  2462 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2463 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2464 
  2465 * New syntax for Haskell-like list comprehension (input only), eg.
  2466 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2467 
  2468 * The special syntax for function "filter" has changed from [x :
  2469 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2470 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2471 
  2472 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2473 defined on nat only, as an abbreviation for [a..<Suc b]
  2474 INCOMPATIBILITY.
  2475 
  2476 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2477 
  2478 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2479 
  2480 * New lemma collection field_simps (an extension of ring_simps) for
  2481 manipulating (in)equations involving division. Multiplies with all
  2482 denominators that can be proved to be non-zero (in equations) or
  2483 positive/negative (in inequations).
  2484 
  2485 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2486 have been improved and renamed to ring_simps, group_simps and
  2487 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2488 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2489 
  2490 * Theory Library/Commutative_Ring: switched from recdef to function
  2491 package; constants add, mul, pow now curried.  Infix syntax for
  2492 algebraic operations.
  2493 
  2494 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2495 INCOMPATIBILITY.
  2496 
  2497 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2498 INCOMPATIBILITY.
  2499 
  2500 * HOL/records: generalised field-update to take a function on the
  2501 field rather than the new value: r(|A := x|) is translated to A_update
  2502 (K x) r The K-combinator that is internally used is called K_record.
  2503 INCOMPATIBILITY: Usage of the plain update functions has to be
  2504 adapted.
  2505  
  2506 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2507 * x = 0, which are required for a semiring.  Richer structures do not
  2508 inherit from semiring_0 anymore, because this property is a theorem
  2509 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2510 there is more to prove, but this is mostly trivial.
  2511 
  2512 * Class "recpower" is generalized to arbitrary monoids, not just
  2513 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2514 commutativity or semiring properties additionally.
  2515 
  2516 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2517 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2518 better use 'abbreviation'.
  2519 
  2520 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2521 
  2522 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2523 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2524 significant changes for setting up numeral syntax for types:
  2525   - New constants Numeral.pred and Numeral.succ instead
  2526       of former Numeral.bin_pred and Numeral.bin_succ.
  2527   - Use integer operations instead of bin_add, bin_mult and so on.
  2528   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2529   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2530 
  2531 See src/HOL/Integ/IntArith.thy for an example setup.
  2532 
  2533 * Command 'normal_form' computes the normal form of a term that may
  2534 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2535 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2536 heavy-duty computations because the functions are compiled to ML
  2537 first.  Correspondingly, a method "normalization" is provided.  See
  2538 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2539 
  2540 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2541 25 like -->); output depends on the "iff" print_mode, the default is
  2542 "A = B" (with priority 50).
  2543 
  2544 * Relations less (<) and less_eq (<=) are also available on type bool.
  2545 Modified syntax to disallow nesting without explicit parentheses,
  2546 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2547 INCOMPATIBILITY.
  2548 
  2549 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2550 
  2551 * Relation composition operator "op O" now has precedence 75 and binds
  2552 stronger than union and intersection. INCOMPATIBILITY.
  2553 
  2554 * The old set interval syntax "{m..n(}" (and relatives) has been
  2555 removed.  Use "{m..<n}" (and relatives) instead.
  2556 
  2557 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2558 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2559 ``declare [[simproc del: neq]]''.
  2560 
  2561 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2562 True/False.
  2563 
  2564 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2565 
  2566 * Theorem setsum_mult renamed to setsum_right_distrib.
  2567 
  2568 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2569 ``rule'' method.
  2570 
  2571 * Reimplemented methods "sat" and "satx", with several improvements:
  2572 goals no longer need to be stated as "<prems> ==> False", equivalences
  2573 (i.e. "=" on type bool) are handled, variable names of the form
  2574 "lit_<n>" are no longer reserved, significant speedup.
  2575 
  2576 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2577 zChaff is still supported as well.
  2578 
  2579 * 'inductive' and 'datatype': provide projections of mutual rules,
  2580 bundled as foo_bar.inducts;
  2581 
  2582 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2583 Library.
  2584 
  2585 * Library: moved theory Accessible_Part to main HOL.
  2586 
  2587 * Library: added theory Coinductive_List of potentially infinite lists
  2588 as greatest fixed-point.
  2589 
  2590 * Library: added theory AssocList which implements (finite) maps as
  2591 association lists.
  2592 
  2593 * Method "evaluation" solves goals (i.e. a boolean expression)
  2594 efficiently by compiling it to ML.  The goal is "proved" (via an
  2595 oracle) if it evaluates to True.
  2596 
  2597 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2598 also when invoked by the simplifier.  This results in the Simplifier
  2599 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2600 Configuration option fast_arith_split_limit=0 recovers the old
  2601 behavior.
  2602 
  2603 * Support for hex (0x20) and binary (0b1001) numerals.
  2604 
  2605 * New method: reify eqs (t), where eqs are equations for an
  2606 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2607 parameter, computes a term s::'b and a list xs::'a list and proves the
  2608 theorem I xs s = t. This is also known as reification or quoting. The
  2609 resulting theorem is applied to the subgoal to substitute t with I xs
  2610 s.  If t is omitted, the subgoal itself is reified.
  2611 
  2612 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2613 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2614 where f is supposed to be a computable function (in the sense of code
  2615 generattion). The method uses reify to compute s and xs as above then
  2616 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2617 r and finally gets the theorem t = r, which is again applied to the
  2618 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2619 
  2620 * Reflection: Automatic reification now handels binding, an example is
  2621 available in src/HOL/ex/ReflectionEx.thy
  2622 
  2623 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2624 command 'statespace' that is similar to 'record', but introduces an
  2625 abstract specification based on the locale infrastructure instead of
  2626 HOL types.  This leads to extra flexibility in composing state spaces,
  2627 in particular multiple inheritance and renaming of components.
  2628 
  2629 
  2630 *** HOL-Complex ***
  2631 
  2632 * Hyperreal: Functions root and sqrt are now defined on negative real
  2633 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2634 Nonnegativity side conditions have been removed from many lemmas, so
  2635 that more subgoals may now be solved by simplification; potential
  2636 INCOMPATIBILITY.
  2637 
  2638 * Real: new type classes formalize real normed vector spaces and
  2639 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2640 and norm :: 'a => real.
  2641 
  2642 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2643 reals into other types. The overloaded constant Reals :: 'a set is now
  2644 defined as range of_real; potential INCOMPATIBILITY.
  2645 
  2646 * Real: proper support for ML code generation, including 'quickcheck'.
  2647 Reals are implemented as arbitrary precision rationals.
  2648 
  2649 * Hyperreal: Several constants that previously worked only for the
  2650 reals have been generalized, so they now work over arbitrary vector
  2651 spaces. Type annotations may need to be added in some cases; potential
  2652 INCOMPATIBILITY.
  2653 
  2654   Infinitesimal  :: ('a::real_normed_vector) star set
  2655   HFinite        :: ('a::real_normed_vector) star set
  2656   HInfinite      :: ('a::real_normed_vector) star set
  2657   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2658   monad          :: ('a::real_normed_vector) star => 'a star set
  2659   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2660   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2661   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2662   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2663   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2664   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2665   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2666   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2667   sgn            :: 'a::real_normed_vector => 'a
  2668   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2669 
  2670 * Complex: Some complex-specific constants are now abbreviations for
  2671 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2672 hnorm.  Other constants have been entirely removed in favor of the
  2673 polymorphic versions (INCOMPATIBILITY):
  2674 
  2675   approx        <-- capprox
  2676   HFinite       <-- CFinite
  2677   HInfinite     <-- CInfinite
  2678   Infinitesimal <-- CInfinitesimal
  2679   monad         <-- cmonad
  2680   galaxy        <-- cgalaxy
  2681   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2682   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2683   (ns)deriv     <-- (ns)cderiv
  2684 
  2685 
  2686 *** HOL-Algebra ***
  2687 
  2688 * Formalisation of ideals and the quotient construction over rings.
  2689 
  2690 * Order and lattice theory no longer based on records.
  2691 INCOMPATIBILITY.
  2692 
  2693 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2694 greatest_closed.  INCOMPATIBILITY.
  2695 
  2696 * Method algebra is now set up via an attribute.  For examples see
  2697 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2698 of algebraic structures.
  2699 
  2700 * Renamed theory CRing to Ring.
  2701 
  2702 
  2703 *** HOL-Nominal ***
  2704 
  2705 * Substantial, yet incomplete support for nominal datatypes (binding
  2706 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2707 src/HOL/Nominal/Examples.  Prospective users should consult
  2708 http://isabelle.in.tum.de/nominal/
  2709 
  2710 
  2711 *** ML ***
  2712 
  2713 * ML basics: just one true type int, which coincides with IntInf.int
  2714 (even on SML/NJ).
  2715 
  2716 * ML within Isar: antiquotations allow to embed statically-checked
  2717 formal entities in the source, referring to the context available at
  2718 compile-time.  For example:
  2719 
  2720 ML {* @{sort "{zero,one}"} *}
  2721 ML {* @{typ "'a => 'b"} *}
  2722 ML {* @{term "%x. x"} *}
  2723 ML {* @{prop "x == y"} *}
  2724 ML {* @{ctyp "'a => 'b"} *}
  2725 ML {* @{cterm "%x. x"} *}
  2726 ML {* @{cprop "x == y"} *}
  2727 ML {* @{thm asm_rl} *}
  2728 ML {* @{thms asm_rl} *}
  2729 ML {* @{type_name c} *}
  2730 ML {* @{type_syntax c} *}
  2731 ML {* @{const_name c} *}
  2732 ML {* @{const_syntax c} *}
  2733 ML {* @{context} *}
  2734 ML {* @{theory} *}
  2735 ML {* @{theory Pure} *}
  2736 ML {* @{theory_ref} *}
  2737 ML {* @{theory_ref Pure} *}
  2738 ML {* @{simpset} *}
  2739 ML {* @{claset} *}
  2740 ML {* @{clasimpset} *}
  2741 
  2742 The same works for sources being ``used'' within an Isar context.
  2743 
  2744 * ML in Isar: improved error reporting; extra verbosity with
  2745 ML_Context.trace enabled.
  2746 
  2747 * Pure/General/table.ML: the join operations now works via exceptions
  2748 DUP/SAME instead of type option. This is simpler in simple cases, and
  2749 admits slightly more efficient complex applications.
  2750 
  2751 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2752 use Context.generic instead of just theory.
  2753 
  2754 * Pure: datatype Context.generic joins theory/Proof.context and
  2755 provides some facilities for code that works in either kind of
  2756 context, notably GenericDataFun for uniform theory and proof data.
  2757 
  2758 * Pure: simplified internal attribute type, which is now always
  2759 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2760 local (Proof.context) attributes have been discontinued, while
  2761 minimizing code duplication. Thm.rule_attribute and
  2762 Thm.declaration_attribute build canonical attributes; see also structure
  2763 Context for further operations on Context.generic, notably
  2764 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2765 declarations and definitions.
  2766 
  2767 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2768 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2769 init only required for impure data. INCOMPATIBILITY: empty really need
  2770 to be empty (no dependencies on theory content!)
  2771 
  2772 * Pure/kernel: consts certification ignores sort constraints given in
  2773 signature declarations. (This information is not relevant to the
  2774 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2775 potential INCOMPATIBILITY.
  2776 
  2777 * Pure: axiomatic type classes are now purely definitional, with
  2778 explicit proofs of class axioms and super class relations performed
  2779 internally. See Pure/axclass.ML for the main internal interfaces --
  2780 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2781 AxClass.axiomatize_class/classrel/arity supersede
  2782 Sign.add_classes/classrel/arities.
  2783 
  2784 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2785 global/local versions on theory vs. Proof.context have been
  2786 discontinued; Attrib.syntax and Method.syntax have been adapted
  2787 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2788 attributes, methods, etc.
  2789 
  2790 * Pure: several functions of signature "... -> theory -> theory * ..."
  2791 have been reoriented to "... -> theory -> ... * theory" in order to
  2792 allow natural usage in combination with the ||>, ||>>, |-> and
  2793 fold_map combinators.
  2794 
  2795 * Pure: official theorem names (closed derivations) and additional
  2796 comments (tags) are now strictly separate.  Name hints -- which are
  2797 maintained as tags -- may be attached any time without affecting the
  2798 derivation.
  2799 
  2800 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2801 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2802 achieve the old behaviour.
  2803 
  2804 * Pure: the "Goal" constant is now called "prop", supporting a
  2805 slightly more general idea of ``protecting'' meta-level rule
  2806 statements.
  2807 
  2808 * Pure: Logic.(un)varify only works in a global context, which is now
  2809 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2810 Logic.legacy_(un)varify as temporary workaround.
  2811 
  2812 * Pure: structure Name provides scalable operations for generating
  2813 internal variable names, notably Name.variants etc.  This replaces
  2814 some popular functions from term.ML:
  2815 
  2816   Term.variant		->  Name.variant
  2817   Term.variantlist	->  Name.variant_list
  2818   Term.invent_names	->  Name.invent_list
  2819 
  2820 Note that low-level renaming rarely occurs in new code -- operations
  2821 from structure Variable are used instead (see below).
  2822 
  2823 * Pure: structure Variable provides fundamental operations for proper
  2824 treatment of fixed/schematic variables in a context.  For example,
  2825 Variable.import introduces fixes for schematics of given facts and
  2826 Variable.export reverses the effect (up to renaming) -- this replaces
  2827 various freeze_thaw operations.
  2828 
  2829 * Pure: structure Goal provides simple interfaces for
  2830 init/conclude/finish and tactical prove operations (replacing former
  2831 Tactic.prove).  Goal.prove is the canonical way to prove results
  2832 within a given context; Goal.prove_global is a degraded version for
  2833 theory level goals, including a global Drule.standard.  Note that
  2834 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2835 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2836 in a locale context).
  2837 
  2838 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2839 and type checking (Syntax.check_term etc.), with common combinations
  2840 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2841 which are considered legacy and await removal.
  2842 
  2843 * Pure/Syntax: generic interfaces for type unchecking
  2844 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2845 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2846 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2847 available for convenience, but refer to the very same operations using
  2848 a mere theory instead of a full context.
  2849 
  2850 * Isar: simplified treatment of user-level errors, using exception
  2851 ERROR of string uniformly.  Function error now merely raises ERROR,
  2852 without any side effect on output channels.  The Isar toplevel takes
  2853 care of proper display of ERROR exceptions.  ML code may use plain
  2854 handle/can/try; cat_error may be used to concatenate errors like this:
  2855 
  2856   ... handle ERROR msg => cat_error msg "..."
  2857 
  2858 Toplevel ML code (run directly or through the Isar toplevel) may be
  2859 embedded into the Isar toplevel with exception display/debug like
  2860 this:
  2861 
  2862   Isar.toplevel (fn () => ...)
  2863 
  2864 INCOMPATIBILITY, removed special transform_error facilities, removed
  2865 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2866 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2867 -- use plain ERROR instead.
  2868 
  2869 * Isar: theory setup now has type (theory -> theory), instead of a
  2870 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2871 
  2872 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2873 ProofContext.debug/verbose flags.
  2874 
  2875 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2876 theory before entering a proof state.  Transactions now always see a
  2877 quasi-functional intermediate checkpoint, both in interactive and
  2878 batch mode.
  2879 
  2880 * Isar: simplified interfaces for outer syntax.  Renamed
  2881 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2882 OuterSyntax.add_parsers -- this functionality is now included in
  2883 OuterSyntax.command etc.  INCOMPATIBILITY.
  2884 
  2885 * Simplifier: the simpset of a running simplification process now
  2886 contains a proof context (cf. Simplifier.the_context), which is the
  2887 very context that the initial simpset has been retrieved from (by
  2888 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2889 (solver, looper etc.) may depend on arbitrary proof data.
  2890 
  2891 * Simplifier.inherit_context inherits the proof context (plus the
  2892 local bounds) of the current simplification process; any simproc
  2893 etc. that calls the Simplifier recursively should do this!  Removed
  2894 former Simplifier.inherit_bounds, which is already included here --
  2895 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2896 specify an explicit context using Simplifier.context/theory_context.
  2897 
  2898 * Simplifier/Classical Reasoner: more abstract interfaces
  2899 change_simpset/claset for modifying the simpset/claset reference of a
  2900 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2901 INCOMPATIBILITY.
  2902 
  2903 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2904 "Trueprop" etc.
  2905 
  2906 
  2907 *** System ***
  2908 
  2909 * settings: the default heap location within ISABELLE_HOME_USER now
  2910 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2911 Isabelle installations.
  2912 
  2913 * isabelle-process: option -S (secure mode) disables some critical
  2914 operations, notably runtime compilation and evaluation of ML source
  2915 code.
  2916 
  2917 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2918 
  2919 * Support for parallel execution, using native multicore support of
  2920 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  2921 independent theories, according to the given theory header
  2922 specifications. The maximum number of worker threads is specified via
  2923 usedir option -M or the "max-threads" setting in Proof General. A
  2924 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  2925 to 6 on a 8-core machine.  User-code needs to observe certain
  2926 guidelines for thread-safe programming, see appendix A in the Isar
  2927 Implementation manual.
  2928 
  2929 
  2930 
  2931 New in Isabelle2005 (October 2005)
  2932 ----------------------------------
  2933 
  2934 *** General ***
  2935 
  2936 * Theory headers: the new header syntax for Isar theories is
  2937 
  2938   theory <name>
  2939   imports <theory1> ... <theoryN>
  2940   uses <file1> ... <fileM>
  2941   begin
  2942 
  2943 where the 'uses' part is optional.  The previous syntax
  2944 
  2945   theory <name> = <theory1> + ... + <theoryN>:
  2946 
  2947 will disappear in the next release.  Use isatool fixheaders to convert
  2948 existing theory files.  Note that there is no change in ancient
  2949 non-Isar theories now, but these will disappear soon.
  2950 
  2951 * Theory loader: parent theories can now also be referred to via
  2952 relative and absolute paths.
  2953 
  2954 * Command 'find_theorems' searches for a list of criteria instead of a
  2955 list of constants. Known criteria are: intro, elim, dest, name:string,
  2956 simp:term, and any term. Criteria can be preceded by '-' to select
  2957 theorems that do not match. Intro, elim, dest select theorems that
  2958 match the current goal, name:s selects theorems whose fully qualified
  2959 name contain s, and simp:term selects all simplification rules whose
  2960 lhs match term.  Any other term is interpreted as pattern and selects
  2961 all theorems matching the pattern. Available in ProofGeneral under
  2962 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  2963 
  2964   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  2965 
  2966 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  2967 matching the current goal as introduction rule and not having "HOL."
  2968 in their name (i.e. not being defined in theory HOL).
  2969 
  2970 * Command 'thms_containing' has been discontinued in favour of
  2971 'find_theorems'; INCOMPATIBILITY.
  2972 
  2973 * Communication with Proof General is now 8bit clean, which means that
  2974 Unicode text in UTF-8 encoding may be used within theory texts (both
  2975 formal and informal parts).  Cf. option -U of the Isabelle Proof
  2976 General interface.  Here are some simple examples (cf. src/HOL/ex):
  2977 
  2978   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  2979   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  2980 
  2981 * Improved efficiency of the Simplifier and, to a lesser degree, the
  2982 Classical Reasoner.  Typical big applications run around 2 times
  2983 faster.
  2984 
  2985 
  2986 *** Document preparation ***
  2987 
  2988 * Commands 'display_drafts' and 'print_drafts' perform simple output
  2989 of raw sources.  Only those symbols that do not require additional
  2990 LaTeX packages (depending on comments in isabellesym.sty) are
  2991 displayed properly, everything else is left verbatim.  isatool display
  2992 and isatool print are used as front ends (these are subject to the
  2993 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  2994 
  2995 * Command tags control specific markup of certain regions of text,
  2996 notably folding and hiding.  Predefined tags include "theory" (for
  2997 theory begin and end), "proof" for proof commands, and "ML" for
  2998 commands involving ML code; the additional tags "visible" and
  2999 "invisible" are unused by default.  Users may give explicit tag
  3000 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3001 interpretation of tags is determined by the LaTeX job during document
  3002 preparation: see option -V of isatool usedir, or options -n and -t of
  3003 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3004 \isadroptag.
  3005 
  3006 Several document versions may be produced at the same time via isatool
  3007 usedir (the generated index.html will link all of them).  Typical
  3008 specifications include ''-V document=theory,proof,ML'' to present
  3009 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3010 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3011 these parts without any formal replacement text.  The Isabelle site
  3012 default settings produce ''document'' and ''outline'' versions as
  3013 specified above.
  3014 
  3015 * Several new antiquotations:
  3016 
  3017   @{term_type term} prints a term with its type annotated;
  3018 
  3019   @{typeof term} prints the type of a term;
  3020 
  3021   @{const const} is the same as @{term const}, but checks that the
  3022   argument is a known logical constant;
  3023 
  3024   @{term_style style term} and @{thm_style style thm} print a term or
  3025   theorem applying a "style" to it
  3026 
  3027   @{ML text}
  3028 
  3029 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3030 definitions, equations, inequations etc., 'concl' printing only the
  3031 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3032 to print the specified premise.  TermStyle.add_style provides an ML
  3033 interface for introducing further styles.  See also the "LaTeX Sugar"
  3034 document practical applications.  The ML antiquotation prints
  3035 type-checked ML expressions verbatim.
  3036 
  3037 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3038 and 'text' support optional locale specification '(in loc)', which
  3039 specifies the default context for interpreting antiquotations.  For
  3040 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3041 
  3042 * Option 'locale=NAME' of antiquotations specifies an alternative
  3043 context interpreting the subsequent argument.  For example: @{thm
  3044 [locale=lattice] inf_assoc}.
  3045 
  3046 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3047 a proof context.
  3048 
  3049 * Proper output of antiquotations for theory commands involving a
  3050 proof context (such as 'locale' or 'theorem (in loc) ...').
  3051 
  3052 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3053 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3054 
  3055 * isatool usedir: new option -C (default true) controls whether option
  3056 -D should include a copy of the original document directory; -C false
  3057 prevents unwanted effects such as copying of administrative CVS data.
  3058 
  3059 
  3060 *** Pure ***
  3061 
  3062 * Considerably improved version of 'constdefs' command.  Now performs
  3063 automatic type-inference of declared constants; additional support for
  3064 local structure declarations (cf. locales and HOL records), see also
  3065 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3066 sequential dependencies of definitions within a single 'constdefs'
  3067 section; moreover, the declared name needs to be an identifier.  If
  3068 all fails, consider to fall back on 'consts' and 'defs' separately.
  3069 
  3070 * Improved indexed syntax and implicit structures.  First of all,
  3071 indexed syntax provides a notational device for subscripted
  3072 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3073 expressions.  Secondly, in a local context with structure
  3074 declarations, number indexes \<^sub>n or the empty index (default
  3075 number 1) refer to a certain fixed variable implicitly; option
  3076 show_structs controls printing of implicit structures.  Typical
  3077 applications of these concepts involve record types and locales.
  3078 
  3079 * New command 'no_syntax' removes grammar declarations (and
  3080 translations) resulting from the given syntax specification, which is
  3081 interpreted in the same manner as for the 'syntax' command.
  3082 
  3083 * 'Advanced' translation functions (parse_translation etc.) may depend
  3084 on the signature of the theory context being presently used for
  3085 parsing/printing, see also isar-ref manual.
  3086 
  3087 * Improved 'oracle' command provides a type-safe interface to turn an
  3088 ML expression of type theory -> T -> term into a primitive rule of
  3089 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3090 is already included here); see also FOL/ex/IffExample.thy;
  3091 INCOMPATIBILITY.
  3092 
  3093 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3094 before); "cI" is no longer bound, use "c.intro" instead.
  3095 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3096 axclasses vs. locales.
  3097 
  3098 * Improved internal renaming of symbolic identifiers -- attach primes
  3099 instead of base 26 numbers.
  3100 
  3101 * New flag show_question_marks controls printing of leading question
  3102 marks in schematic variable names.
  3103 
  3104 * In schematic variable names, *any* symbol following \<^isub> or
  3105 \<^isup> is now treated as part of the base name.  For example, the
  3106 following works without printing of awkward ".0" indexes:
  3107 
  3108   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3109     by simp
  3110 
  3111 * Inner syntax includes (*(*nested*) comments*).
  3112 
  3113 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3114 annotations as "(00...)".
  3115 
  3116 * Clear separation of logical types and nonterminals, where the latter
  3117 may only occur in 'syntax' specifications or type abbreviations.
  3118 Before that distinction was only partially implemented via type class
  3119 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3120 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3121 exotic syntax specifications may require further adaption
  3122 (e.g. Cube/Cube.thy).
  3123 
  3124 * Removed obsolete type class "logic", use the top sort {} instead.
  3125 Note that non-logical types should be declared as 'nonterminals'
  3126 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3127 specifications.
  3128 
  3129 * Attributes 'induct' and 'cases': type or set names may now be
  3130 locally fixed variables as well.
  3131 
  3132 * Simplifier: can now control the depth to which conditional rewriting
  3133 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3134 Limit.
  3135 
  3136 * Simplifier: simplification procedures may now take the current
  3137 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3138 interface), which is very useful for calling the Simplifier
  3139 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3140 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3141 low-level mk_simproc no longer applies Logic.varify internally, to
  3142 allow for use in a context of fixed variables.
  3143 
  3144 * thin_tac now works even if the assumption being deleted contains !!
  3145 or ==>.  More generally, erule now works even if the major premise of
  3146 the elimination rule contains !! or ==>.
  3147 
  3148 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3149 
  3150 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3151 from Pure, which contains all common declarations already.  Both
  3152 theories are defined via plain Isabelle/Isar .thy files.
  3153 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3154 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3155 use isatool fixcpure to adapt your theory and ML sources.
  3156 
  3157 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3158 selections of theorems in named facts via index ranges.
  3159 
  3160 * 'print_theorems': in theory mode, really print the difference
  3161 wrt. the last state (works for interactive theory development only),
  3162 in proof mode print all local facts (cf. 'print_facts');
  3163 
  3164 * 'hide': option '(open)' hides only base names.
  3165 
  3166 * More efficient treatment of intermediate checkpoints in interactive
  3167 theory development.
  3168 
  3169 * Code generator is now invoked via code_module (incremental code
  3170 generation) and code_library (modular code generation, ML structures
  3171 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3172 must be quoted when used as identifiers.
  3173 
  3174 * New 'value' command for reading, evaluating and printing terms using
  3175 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3176 quoted when used as identifier.
  3177 
  3178 
  3179 *** Locales ***
  3180 
  3181 * New commands for the interpretation of locale expressions in
  3182 theories (1), locales (2) and proof contexts (3).  These generate
  3183 proof obligations from the expression specification.  After the
  3184 obligations have been discharged, theorems of the expression are added
  3185 to the theory, target locale or proof context.  The synopsis of the
  3186 commands is a follows:
  3187 
  3188   (1) interpretation expr inst
  3189   (2) interpretation target < expr
  3190   (3) interpret expr inst
  3191 
  3192 Interpretation in theories and proof contexts require a parameter
  3193 instantiation of terms from the current context.  This is applied to
  3194 specifications and theorems of the interpreted expression.
  3195 Interpretation in locales only permits parameter renaming through the
  3196 locale expression.  Interpretation is smart in that interpretations
  3197 that are active already do not occur in proof obligations, neither are
  3198 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3199 inspect active interpretations of a particular locale.  For details,
  3200 see the Isar Reference manual.  Examples can be found in
  3201 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3202 
  3203 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3204 'interpret' instead.
  3205 
  3206 * New context element 'constrains' for adding type constraints to
  3207 parameters.
  3208 
  3209 * Context expressions: renaming of parameters with syntax
  3210 redeclaration.
  3211 
  3212 * Locale declaration: 'includes' disallowed.
  3213 
  3214 * Proper static binding of attribute syntax -- i.e. types / terms /
  3215 facts mentioned as arguments are always those of the locale definition
  3216 context, independently of the context of later invocations.  Moreover,
  3217 locale operations (renaming and type / term instantiation) are applied
  3218 to attribute arguments as expected.
  3219 
  3220 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3221 actual attributes; rare situations may require Attrib.attribute to
  3222 embed those attributes into Attrib.src that lack concrete syntax.
  3223 Attribute implementations need to cooperate properly with the static
  3224 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3225 Attrib.XXX_thm etc. already do the right thing without further
  3226 intervention.  Only unusual applications -- such as "where" or "of"
  3227 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3228 on the context and the facts involved -- may have to assign parsed
  3229 values to argument tokens explicitly.
  3230 
  3231 * Changed parameter management in theorem generation for long goal
  3232 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3233 theorem statement in rare situations.
  3234 
  3235 * Locale inspection command 'print_locale' omits notes elements.  Use
  3236 'print_locale!' to have them included in the output.
  3237 
  3238 
  3239 *** Provers ***
  3240 
  3241 * Provers/hypsubst.ML: improved version of the subst method, for
  3242 single-step rewriting: it now works in bound variable contexts. New is
  3243 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3244 rewrite a different subterm than the original subst method, which is
  3245 still available as 'simplesubst'.
  3246 
  3247 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3248 and quasi orders.
  3249 
  3250 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3251 reflexive-transitive closure of relations.
  3252 
  3253 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3254 limit (previously hard-coded with a value of 20) user-definable.
  3255 
  3256 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3257 is peformed already.  Object-logics merely need to finish their
  3258 initial simpset configuration as before.  INCOMPATIBILITY.
  3259 
  3260 
  3261 *** HOL ***
  3262 
  3263 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3264 
  3265   syntax (epsilon)
  3266     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3267 
  3268 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3269 and x-symbol; use option '-m epsilon' to get it actually printed.
  3270 Moreover, the mathematically important symbolic identifier \<epsilon>
  3271 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3272 
  3273 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3274 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3275 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3276 support corresponding Isar calculations.
  3277 
  3278 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3279 instead of ":".
  3280 
  3281 * theory SetInterval: changed the syntax for open intervals:
  3282 
  3283   Old       New
  3284   {..n(}    {..<n}
  3285   {)n..}    {n<..}
  3286   {m..n(}   {m..<n}
  3287   {)m..n}   {m<..n}
  3288   {)m..n(}  {m<..<n}
  3289 
  3290 The old syntax is still supported but will disappear in the next
  3291 release.  For conversion use the following Emacs search and replace
  3292 patterns (these are not perfect but work quite well):
  3293 
  3294   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3295   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3296 
  3297 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3298 equalities in commutative rings; method 'algebra' provides a generic
  3299 interface.
  3300 
  3301 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3302 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3303 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3304 be a tuple pattern.
  3305 
  3306 Some new syntax forms are available:
  3307 
  3308   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3309   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3310   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3311   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3312 
  3313 The latter form "\<Sum>x < k. e" used to be based on a separate
  3314 function "Summation", which has been discontinued.
  3315 
  3316 * theory Finite_Set: in structured induction proofs, the insert case
  3317 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3318 (insert F x)'.
  3319 
  3320 * The 'refute' command has been extended to support a much larger
  3321 fragment of HOL, including axiomatic type classes, constdefs and
  3322 typedefs, inductive datatypes and recursion.
  3323 
  3324 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3325 Requires zChaff with proof generation to be installed.  See
  3326 HOL/ex/SAT_Examples.thy for examples.
  3327 
  3328 * Datatype induction via method 'induct' now preserves the name of the
  3329 induction variable. For example, when proving P(xs::'a list) by
  3330 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3331 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3332 in unstructured proof scripts.
  3333 
  3334 * Reworked implementation of records.  Improved scalability for
  3335 records with many fields, avoiding performance problems for type
  3336 inference. Records are no longer composed of nested field types, but
  3337 of nested extension types. Therefore the record type only grows linear
  3338 in the number of extensions and not in the number of fields.  The
  3339 top-level (users) view on records is preserved.  Potential
  3340 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3341 old record representation. The type generated for a record is called
  3342 <record_name>_ext_type.
  3343 
  3344 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3345 proofs triggered by a record definition or a simproc (if
  3346 quick_and_dirty is enabled).  Definitions of large records can take
  3347 quite long.
  3348 
  3349 New simproc record_upd_simproc for simplification of multiple record
  3350 updates enabled by default.  Moreover, trivial updates are also
  3351 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3352 occasionally, since simplification is more powerful by default.
  3353 
  3354 * typedef: proper support for polymorphic sets, which contain extra
  3355 type-variables in the term.
  3356 
  3357 * Simplifier: automatically reasons about transitivity chains
  3358 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3359 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3360 old proofs break occasionally as simplification may now solve more
  3361 goals than previously.
  3362 
  3363 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3364 present.  Works for all partial orders (class "order"), in particular
  3365 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3366 just like y <= x.
  3367 
  3368 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3369 bound variable or a constant then the let is unfolded.  Otherwise
  3370 first a is simplified to b, and then f b is simplified to g. If
  3371 possible we abstract b from g arriving at "let x = b in h x",
  3372 otherwise we unfold the let and arrive at g.  The simproc can be
  3373 enabled/disabled by the reference use_let_simproc.  Potential
  3374 INCOMPATIBILITY since simplification is more powerful by default.
  3375 
  3376 * Classical reasoning: the meson method now accepts theorems as arguments.
  3377 
  3378 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3379 jobs to provide advice on the provability of subgoals.
  3380 
  3381 * Theory OrderedGroup and Ring_and_Field: various additions and
  3382 improvements to faciliate calculations involving equalities and
  3383 inequalities.
  3384 
  3385 The following theorems have been eliminated or modified
  3386 (INCOMPATIBILITY):
  3387 
  3388   abs_eq             now named abs_of_nonneg
  3389   abs_of_ge_0        now named abs_of_nonneg
  3390   abs_minus_eq       now named abs_of_nonpos
  3391   imp_abs_id         now named abs_of_nonneg
  3392   imp_abs_neg_id     now named abs_of_nonpos
  3393   mult_pos           now named mult_pos_pos
  3394   mult_pos_le        now named mult_nonneg_nonneg
  3395   mult_pos_neg_le    now named mult_nonneg_nonpos
  3396   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3397   mult_neg           now named mult_neg_neg
  3398   mult_neg_le        now named mult_nonpos_nonpos
  3399 
  3400 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3401      
  3402      zero_le_square
  3403      not_square_less_zero 
  3404 
  3405   The following lemmas have been deleted from Real/RealPow:
  3406   
  3407      realpow_zero_zero
  3408      realpow_two
  3409      realpow_less
  3410      zero_le_power
  3411      realpow_two_le
  3412      abs_realpow_two
  3413      realpow_two_abs     
  3414 
  3415 * Theory Parity: added rules for simplifying exponents.
  3416 
  3417 * Theory List:
  3418 
  3419 The following theorems have been eliminated or modified
  3420 (INCOMPATIBILITY):
  3421 
  3422   list_all_Nil       now named list_all.simps(1)
  3423   list_all_Cons      now named list_all.simps(2)
  3424   list_all_conv      now named list_all_iff
  3425   set_mem_eq         now named mem_iff
  3426 
  3427 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3428 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3429 
  3430 
  3431 *** HOL-Complex ***
  3432 
  3433 * Theory RealDef: better support for embedding natural numbers and
  3434 integers in the reals.
  3435 
  3436 The following theorems have been eliminated or modified
  3437 (INCOMPATIBILITY):
  3438 
  3439   exp_ge_add_one_self  now requires no hypotheses
  3440   real_of_int_add      reversed direction of equality (use [symmetric])
  3441   real_of_int_minus    reversed direction of equality (use [symmetric])
  3442   real_of_int_diff     reversed direction of equality (use [symmetric])
  3443   real_of_int_mult     reversed direction of equality (use [symmetric])
  3444 
  3445 * Theory RComplete: expanded support for floor and ceiling functions.
  3446 
  3447 * Theory Ln is new, with properties of the natural logarithm
  3448 
  3449 * Hyperreal: There is a new type constructor "star" for making
  3450 nonstandard types.  The old type names are now type synonyms:
  3451 
  3452   hypreal = real star
  3453   hypnat = nat star
  3454   hcomplex = complex star
  3455 
  3456 * Hyperreal: Many groups of similarly-defined constants have been
  3457 replaced by polymorphic versions (INCOMPATIBILITY):
  3458 
  3459   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3460 
  3461   starset      <-- starsetNat, starsetC
  3462   *s*          <-- *sNat*, *sc*
  3463   starset_n    <-- starsetNat_n, starsetC_n
  3464   *sn*         <-- *sNatn*, *scn*
  3465   InternalSets <-- InternalNatSets, InternalCSets
  3466 
  3467   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3468   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3469   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3470   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3471   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3472 
  3473 * Hyperreal: Many type-specific theorems have been removed in favor of
  3474 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3475 
  3476   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3477   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3478   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3479   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3480   right_minus <-- hypreal_add_minus
  3481   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3482   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3483   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3484   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3485   mult_1_right <-- hcomplex_mult_one_right
  3486   mult_zero_left <-- hcomplex_mult_zero_left
  3487   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3488   right_distrib <-- hypnat_add_mult_distrib2
  3489   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3490   right_inverse <-- hypreal_mult_inverse
  3491   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3492   order_refl <-- {hypreal,hypnat}_le_refl
  3493   order_trans <-- {hypreal,hypnat}_le_trans
  3494   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3495   order_less_le <-- {hypreal,hypnat}_less_le
  3496   linorder_linear <-- {hypreal,hypnat}_le_linear
  3497   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3498   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3499   add_nonneg_nonneg <-- hypreal_le_add_order
  3500 
  3501 * Hyperreal: Separate theorems having to do with type-specific
  3502 versions of constants have been merged into theorems that apply to the
  3503 new polymorphic constants (INCOMPATIBILITY):
  3504 
  3505   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3506   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3507   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3508   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3509   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3510   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3511   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3512   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3513   STAR_diff <-- {STAR,STARC}_diff
  3514   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3515     STARC_hcomplex_of_complex}_image_subset
  3516   starset_n_Un <-- starset{Nat,C}_n_Un
  3517   starset_n_Int <-- starset{Nat,C}_n_Int
  3518   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3519   starset_n_diff <-- starset{Nat,C}_n_diff
  3520   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3521   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3522   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3523   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3524   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3525   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3526   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3527   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3528   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3529   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3530   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3531   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3532   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3533   starfun_diff <-- starfun{C,RC,CR}_diff
  3534   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3535   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3536   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3537   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3538   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3539   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3540   starfun_Id <-- starfunC_Id
  3541   starfun_approx <-- starfun{Nat,CR}_approx
  3542   starfun_capprox <-- starfun{C,RC}_capprox
  3543   starfun_abs <-- starfunNat_rabs
  3544   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3545   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3546   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3547   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3548   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3549   starfun_add_approx <-- starfunCR_add_approx
  3550   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3551   starfun_divide <-- starfun{C,CR,RC}_divide
  3552   starfun_n <-- starfun{Nat,C}_n
  3553   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3554   starfun_n_add <-- starfun{Nat,C}_n_add
  3555   starfun_n_add_minus <-- starfunNat_n_add_minus
  3556   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3557   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3558   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3559 
  3560   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3561   star_n_minus <-- {hypreal,hcomplex}_minus
  3562   star_n_diff <-- {hypreal,hcomplex}_diff
  3563   star_n_mult <-- {hypreal,hcomplex}_mult
  3564   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3565   star_n_le <-- {hypreal,hypnat}_le
  3566   star_n_less <-- {hypreal,hypnat}_less
  3567   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3568   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3569   star_n_abs <-- hypreal_hrabs
  3570   star_n_divide <-- hcomplex_divide
  3571 
  3572   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3573   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3574   star_of_diff <-- hypreal_of_real_diff
  3575   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3576   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3577   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3578   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3579   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3580   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3581   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3582   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3583   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3584   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3585   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3586   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3587   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3588   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3589   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3590   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3591   star_of_power <-- hypreal_of_real_power
  3592   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3593 
  3594 * Hyperreal: new method "transfer" that implements the transfer
  3595 principle of nonstandard analysis. With a subgoal that mentions
  3596 nonstandard types like "'a star", the command "apply transfer"
  3597 replaces it with an equivalent one that mentions only standard types.
  3598 To be successful, all free variables must have standard types; non-
  3599 standard variables must have explicit universal quantifiers.
  3600 
  3601 * Hyperreal: A theory of Taylor series.
  3602 
  3603 
  3604 *** HOLCF ***
  3605 
  3606 * Discontinued special version of 'constdefs' (which used to support
  3607 continuous functions) in favor of the general Pure one with full
  3608 type-inference.
  3609 
  3610 * New simplification procedure for solving continuity conditions; it
  3611 is much faster on terms with many nested lambda abstractions (cubic
  3612 instead of exponential time).
  3613 
  3614 * New syntax for domain package: selector names are now optional.
  3615 Parentheses should be omitted unless argument is lazy, for example:
  3616 
  3617   domain 'a stream = cons "'a" (lazy "'a stream")
  3618 
  3619 * New command 'fixrec' for defining recursive functions with pattern
  3620 matching; defining multiple functions with mutual recursion is also
  3621 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3622 sinr, or any data constructor defined by the domain package. The given
  3623 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3624 syntax and examples.
  3625 
  3626 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3627 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3628 but the proof obligation additionally includes an admissibility
  3629 requirement. The packages generate instances of class cpo or pcpo,
  3630 with continuity and strictness theorems for Rep and Abs.
  3631 
  3632 * HOLCF: Many theorems have been renamed according to a more standard naming
  3633 scheme (INCOMPATIBILITY):
  3634 
  3635   foo_inject:  "foo$x = foo$y ==> x = y"
  3636   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3637   foo_less:    "(foo$x << foo$y) = (x << y)"
  3638   foo_strict:  "foo$UU = UU"
  3639   foo_defined: "... ==> foo$x ~= UU"
  3640   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3641 
  3642 
  3643 *** ZF ***
  3644 
  3645 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3646 including the First Isomorphism Theorem (on quotienting by the kernel
  3647 of a homomorphism).
  3648 
  3649 * ZF/Simplifier: install second copy of type solver that actually
  3650 makes use of TC rules declared to Isar proof contexts (or locales);
  3651 the old version is still required for ML proof scripts.
  3652 
  3653 
  3654 *** Cube ***
  3655 
  3656 * Converted to Isar theory format; use locales instead of axiomatic
  3657 theories.
  3658 
  3659 
  3660 *** ML ***
  3661 
  3662 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3663 for ||>, ||>>, |>>,
  3664 
  3665 * Pure/library.ML no longer defines its own option datatype, but uses
  3666 that of the SML basis, which has constructors NONE and SOME instead of
  3667 None and Some, as well as exception Option.Option instead of OPTION.
  3668 The functions the, if_none, is_some, is_none have been adapted
  3669 accordingly, while Option.map replaces apsome.
  3670 
  3671 * Pure/library.ML: the exception LIST has been given up in favour of
  3672 the standard exceptions Empty and Subscript, as well as
  3673 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3674 superceded by the standard hd and tl functions etc.
  3675 
  3676 A number of basic list functions are no longer exported to the ML
  3677 toplevel, as they are variants of predefined functions.  The following
  3678 suggests how one can translate existing code:
  3679 
  3680     rev_append xs ys = List.revAppend (xs, ys)
  3681     nth_elem (i, xs) = List.nth (xs, i)
  3682     last_elem xs = List.last xs
  3683     flat xss = List.concat xss
  3684     seq fs = List.app fs
  3685     partition P xs = List.partition P xs
  3686     mapfilter f xs = List.mapPartial f xs
  3687 
  3688 * Pure/library.ML: several combinators for linear functional
  3689 transformations, notably reverse application and composition:
  3690 
  3691   x |> f                f #> g
  3692   (x, y) |-> f          f #-> g
  3693 
  3694 * Pure/library.ML: introduced/changed precedence of infix operators:
  3695 
  3696   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3697   infix 2 ?;
  3698   infix 3 o oo ooo oooo;
  3699   infix 4 ~~ upto downto;
  3700 
  3701 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3702 infix operators.
  3703 
  3704 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3705 fold_map support linear functional transformations and nesting.  For
  3706 example:
  3707 
  3708   fold f [x1, ..., xN] y =
  3709     y |> f x1 |> ... |> f xN
  3710 
  3711   (fold o fold) f [xs1, ..., xsN] y =
  3712     y |> fold f xs1 |> ... |> fold f xsN
  3713 
  3714   fold f [x1, ..., xN] =
  3715     f x1 #> ... #> f xN
  3716 
  3717   (fold o fold) f [xs1, ..., xsN] =
  3718     fold f xs1 #> ... #> fold f xsN
  3719 
  3720 * Pure/library.ML: the following selectors on type 'a option are
  3721 available:
  3722 
  3723   the:               'a option -> 'a  (*partial*)
  3724   these:             'a option -> 'a  where 'a = 'b list
  3725   the_default: 'a -> 'a option -> 'a
  3726   the_list:          'a option -> 'a list
  3727 
  3728 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3729 basic operations for association lists, following natural argument
  3730 order; moreover the explicit equality predicate passed here avoids
  3731 potentially expensive polymorphic runtime equality checks.
  3732 The old functions may be expressed as follows:
  3733 
  3734   assoc = uncurry (AList.lookup (op =))
  3735   assocs = these oo AList.lookup (op =)
  3736   overwrite = uncurry (AList.update (op =)) o swap
  3737 
  3738 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3739 
  3740   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3741   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3742 
  3743 replacing make_keylist and keyfilter (occassionally used)
  3744 Naive rewrites:
  3745 
  3746   make_keylist = AList.make
  3747   keyfilter = AList.find (op =)
  3748 
  3749 * eq_fst and eq_snd now take explicit equality parameter, thus
  3750   avoiding eqtypes. Naive rewrites:
  3751 
  3752     eq_fst = eq_fst (op =)
  3753     eq_snd = eq_snd (op =)
  3754 
  3755 * Removed deprecated apl and apr (rarely used).
  3756   Naive rewrites:
  3757 
  3758     apl (n, op) =>>= curry op n
  3759     apr (op, m) =>>= fn n => op (n, m)
  3760 
  3761 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3762 provides a reasonably efficient light-weight implementation of sets as
  3763 lists.
  3764 
  3765 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3766 few new operations; existing lookup and update are now curried to
  3767 follow natural argument order (for use with fold etc.);
  3768 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3769 
  3770 * Pure/General: output via the Isabelle channels of
  3771 writeln/warning/error etc. is now passed through Output.output, with a
  3772 hook for arbitrary transformations depending on the print_mode
  3773 (cf. Output.add_mode -- the first active mode that provides a output
  3774 function wins).  Already formatted output may be embedded into further
  3775 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3776 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3777 accommodate easy composition of diagnostic messages etc.  Programmers
  3778 rarely need to care about Output.output or Output.raw at all, with
  3779 some notable exceptions: Output.output is required when bypassing the
  3780 standard channels (writeln etc.), or in token translations to produce
  3781 properly formatted results; Output.raw is required when capturing
  3782 already output material that will eventually be presented to the user
  3783 a second time.  For the default print mode, both Output.output and
  3784 Output.raw have no effect.
  3785 
  3786 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3787 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3788 cumulative results are displayed at the end of a batch session.
  3789 
  3790 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3791 replaced by File.platform_path and File.shell_path (with appropriate
  3792 hooks).  This provides a clean interface for unusual systems where the
  3793 internal and external process view of file names are different.
  3794 
  3795 * Pure: more efficient orders for basic syntactic entities: added
  3796 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3797 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3798 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3799 orders now -- potential INCOMPATIBILITY for code that depends on a
  3800 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3801 Library.sort_strings on result).
  3802 
  3803 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3804 fold_types traverse types/terms from left to right, observing natural
  3805 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3806 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3807 
  3808 * Pure: name spaces have been refined, with significant changes of the
  3809 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3810 to extern(_table).  The plain name entry path is superceded by a
  3811 general 'naming' context, which also includes the 'policy' to produce
  3812 a fully qualified name and external accesses of a fully qualified
  3813 name; NameSpace.extend is superceded by context dependent
  3814 Sign.declare_name.  Several theory and proof context operations modify
  3815 the naming context.  Especially note Theory.restore_naming and
  3816 ProofContext.restore_naming to get back to a sane state; note that
  3817 Theory.add_path is no longer sufficient to recover from
  3818 Theory.absolute_path in particular.
  3819 
  3820 * Pure: new flags short_names (default false) and unique_names
  3821 (default true) for controlling output of qualified names.  If
  3822 short_names is set, names are printed unqualified.  If unique_names is
  3823 reset, the name prefix is reduced to the minimum required to achieve
  3824 the original result when interning again, even if there is an overlap
  3825 with earlier declarations.
  3826 
  3827 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3828 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3829 (useful for printing error messages).  INCOMPATIBILITY.
  3830 
  3831 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3832 Theory.theory are now identified, referring to the universal
  3833 Context.theory (see Pure/context.ML).  Actual signature and theory
  3834 content is managed as theory data.  The old code and interfaces were
  3835 spread over many files and structures; the new arrangement introduces
  3836 considerable INCOMPATIBILITY to gain more clarity:
  3837 
  3838   Context -- theory management operations (name, identity, inclusion,
  3839     parents, ancestors, merge, etc.), plus generic theory data;
  3840 
  3841   Sign -- logical signature and syntax operations (declaring consts,
  3842     types, etc.), plus certify/read for common entities;
  3843 
  3844   Theory -- logical theory operations (stating axioms, definitions,
  3845     oracles), plus a copy of logical signature operations (consts,
  3846     types, etc.); also a few basic management operations (Theory.copy,
  3847     Theory.merge, etc.)
  3848 
  3849 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3850 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3851 for convenience -- they merely return the theory.
  3852 
  3853 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3854 
  3855 * Pure: the Isar proof context type is already defined early in Pure
  3856 as Context.proof (note that ProofContext.context and Proof.context are
  3857 aliases, where the latter is the preferred name).  This enables other
  3858 Isabelle components to refer to that type even before Isar is present.
  3859 
  3860 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3861 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3862 any of these kinds.  For example, Sign.intern typeK is now
  3863 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3864 Theory.hide_types.  Also note that former
  3865 Theory.hide_classes/types/consts are now
  3866 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3867 internalize their arguments!  INCOMPATIBILITY.
  3868 
  3869 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3870 datatype thmref (with constructors Name and NameSelection) instead of
  3871 plain string -- INCOMPATIBILITY;
  3872 
  3873 * Pure: cases produced by proof methods specify options, where NONE
  3874 means to remove case bindings -- INCOMPATIBILITY in
  3875 (RAW_)METHOD_CASES.
  3876 
  3877 * Pure: the following operations retrieve axioms or theorems from a
  3878 theory node or theory hierarchy, respectively:
  3879 
  3880   Theory.axioms_of: theory -> (string * term) list
  3881   Theory.all_axioms_of: theory -> (string * term) list
  3882   PureThy.thms_of: theory -> (string * thm) list
  3883   PureThy.all_thms_of: theory -> (string * thm) list
  3884 
  3885 * Pure: print_tac now outputs the goal through the trace channel.
  3886 
  3887 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3888 Reference Toplevel.debug (default false) controls detailed printing
  3889 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3890 controls execution profiling -- set to 1 for time and 2 for space
  3891 (both increase the runtime).
  3892 
  3893 * Isar session: The initial use of ROOT.ML is now always timed,
  3894 i.e. the log will show the actual process times, in contrast to the
  3895 elapsed wall-clock time that the outer shell wrapper produces.
  3896 
  3897 * Simplifier: improved handling of bound variables (nameless
  3898 representation, avoid allocating new strings).  Simprocs that invoke
  3899 the Simplifier recursively should use Simplifier.inherit_bounds to
  3900 avoid local name clashes.  Failure to do so produces warnings
  3901 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3902 for further details.
  3903 
  3904 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3905 bindings for all theorems stored within a given theory; this may help
  3906 in porting non-Isar theories to Isar ones, while keeping ML proof
  3907 scripts for the time being.
  3908 
  3909 * ML operator HTML.with_charset specifies the charset begin used for
  3910 generated HTML files.  For example:
  3911 
  3912   HTML.with_charset "utf-8" use_thy "Hebrew";
  3913   HTML.with_charset "utf-8" use_thy "Chinese";
  3914 
  3915 
  3916 *** System ***
  3917 
  3918 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3919 isabelle, isatool etc.).
  3920 
  3921 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  3922 isatool doc, isatool mkdir, display_drafts etc.).
  3923 
  3924 * isatool usedir: option -f allows specification of the ML file to be
  3925 used by Isabelle; default is ROOT.ML.
  3926 
  3927 * New isatool version outputs the version identifier of the Isabelle
  3928 distribution being used.
  3929 
  3930 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  3931 (containing Boolean satisfiability problems) into Isabelle/HOL
  3932 theories.
  3933 
  3934 
  3935 
  3936 New in Isabelle2004 (April 2004)
  3937 --------------------------------
  3938 
  3939 *** General ***
  3940 
  3941 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  3942   Replaces linorder.ML.
  3943 
  3944 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  3945   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  3946   (\<a>...\<z>), are now considered normal letters, and can therefore
  3947   be used anywhere where an ASCII letter (a...zA...Z) has until
  3948   now. COMPATIBILITY: This obviously changes the parsing of some
  3949   terms, especially where a symbol has been used as a binder, say
  3950   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  3951   as an identifier.  Fix it by inserting a space around former
  3952   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  3953   existing theory and ML files.
  3954 
  3955 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  3956 
  3957 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  3958   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  3959   a normal (but invisible) letter. For multiple letter subscripts repeat
  3960   \<^isub> like this: x\<^isub>1\<^isub>2.
  3961 
  3962 * Pure: There are now sub-/superscripts that can span more than one
  3963   character. Text between \<^bsub> and \<^esub> is set in subscript in
  3964   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  3965   superscript. The new control characters are not identifier parts.
  3966 
  3967 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  3968   content of "..." to the latex file instead of \isacntrl... . The "..."
  3969   may consist of any printable characters excluding the end bracket >.
  3970 
  3971 * Pure: Using new Isar command "finalconsts" (or the ML functions
  3972   Theory.add_finals or Theory.add_finals_i) it is now possible to
  3973   declare constants "final", which prevents their being given a definition
  3974   later.  It is useful for constants whose behaviour is fixed axiomatically
  3975   rather than definitionally, such as the meta-logic connectives.
  3976 
  3977 * Pure: 'instance' now handles general arities with general sorts
  3978   (i.e. intersections of classes),
  3979 
  3980 * Presentation: generated HTML now uses a CSS style sheet to make layout
  3981   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  3982   It can be changed to alter the colors/layout of generated pages.
  3983 
  3984 
  3985 *** Isar ***
  3986 
  3987 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  3988   cut_tac, subgoal_tac and thin_tac:
  3989   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  3990     locales are no longer forced to write Isar proof scripts.
  3991     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  3992     emulations.
  3993   - INCOMPATIBILITY: names of variables to be instantiated may no
  3994     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  3995     This is consistent with the instantiation attribute "where".
  3996 
  3997 * Attributes "where" and "of":
  3998   - Now take type variables of instantiated theorem into account when reading
  3999     the instantiation string.  This fixes a bug that caused instantiated
  4000     theorems to have too special types in some circumstances.
  4001   - "where" permits explicit instantiations of type variables.
  4002 
  4003 * Calculation commands "moreover" and "also" no longer interfere with
  4004   current facts ("this"), admitting arbitrary combinations with "then"
  4005   and derived forms.
  4006 
  4007 * Locales:
  4008   - Goal statements involving the context element "includes" no longer
  4009     generate theorems with internal delta predicates (those ending on
  4010     "_axioms") in the premise.
  4011     Resolve particular premise with <locale>.intro to obtain old form.
  4012   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4013     specification and "includes" elements in goal statement.
  4014   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4015     [intro?] and [elim?] (respectively) by default.
  4016   - Experimental command for instantiation of locales in proof contexts:
  4017         instantiate <label>[<attrs>]: <loc>
  4018     Instantiates locale <loc> and adds all its theorems to the current context
  4019     taking into account their attributes.  Label and attrs are optional
  4020     modifiers, like in theorem declarations.  If present, names of
  4021     instantiated theorems are qualified with <label>, and the attributes
  4022     <attrs> are applied after any attributes these theorems might have already.
  4023       If the locale has assumptions, a chained fact of the form
  4024     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4025     are derived.  The command does not support old-style locales declared
  4026     with "locale (open)".
  4027       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4028 
  4029 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4030   (Isar) contexts.
  4031 
  4032 
  4033 *** HOL ***
  4034 
  4035 * Proof import: new image HOL4 contains the imported library from
  4036   the HOL4 system with about 2500 theorems. It is imported by
  4037   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4038   can be used like any other Isabelle image.  See
  4039   HOL/Import/HOL/README for more information.
  4040 
  4041 * Simplifier:
  4042   - Much improved handling of linear and partial orders.
  4043     Reasoners for linear and partial orders are set up for type classes
  4044     "linorder" and "order" respectively, and are added to the default simpset
  4045     as solvers.  This means that the simplifier can build transitivity chains
  4046     to solve goals from the assumptions.
  4047   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4048     of blast or auto after simplification become unnecessary because the goal
  4049     is solved by simplification already.
  4050 
  4051 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4052     all proved in axiomatic type classes for semirings, rings and fields.
  4053 
  4054 * Numerics:
  4055   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4056     now formalized using the Ring_and_Field theory mentioned above.
  4057   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4058     than before, because now they are set up once in a generic manner.
  4059   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4060     Look for the general versions in Ring_and_Field (and Power if they concern
  4061     exponentiation).
  4062 
  4063 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4064 
  4065 * Records:
  4066   - Record types are now by default printed with their type abbreviation
  4067     instead of the list of all field types. This can be configured via
  4068     the reference "print_record_type_abbr".
  4069   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4070     (not enabled by default).
  4071   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4072     EX x. x = sel r to True (not enabled by default).
  4073   - Tactic "record_split_simp_tac" to split and simplify records added.
  4074 
  4075 * 'specification' command added, allowing for definition by
  4076   specification.  There is also an 'ax_specification' command that
  4077   introduces the new constants axiomatically.
  4078 
  4079 * arith(_tac) is now able to generate counterexamples for reals as well.
  4080 
  4081 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4082 
  4083 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4084   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4085 
  4086 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4087   matrix theory to linear programming.
  4088 
  4089 * Unions and Intersections:
  4090   The latex output syntax of UN and INT has been changed
  4091   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4092   i.e. the index formulae has become a subscript.
  4093   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4094 
  4095 * Unions and Intersections over Intervals:
  4096   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4097   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4098   like in normal math, and corresponding versions for < and for intersection.
  4099 
  4100 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4101   lexicographic dictonary ordering has been added as "lexord".
  4102 
  4103 * ML: the legacy theory structures Int and List have been removed. They had
  4104   conflicted with ML Basis Library structures having the same names.
  4105 
  4106 * 'refute' command added to search for (finite) countermodels.  Only works
  4107   for a fragment of HOL.  The installation of an external SAT solver is
  4108   highly recommended.  See "HOL/Refute.thy" for details.
  4109 
  4110 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4111   formulae under an assignment of free variables to random values.
  4112   In contrast to 'refute', it can deal with inductive datatypes,
  4113   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4114   for examples.
  4115 
  4116 
  4117 *** HOLCF ***
  4118 
  4119 * Streams now come with concatenation and are part of the HOLCF image
  4120 
  4121 
  4122 
  4123 New in Isabelle2003 (May 2003)
  4124 ------------------------------
  4125 
  4126 *** General ***
  4127 
  4128 * Provers/simplifier:
  4129 
  4130   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4131     Assumptions are now subject to complete mutual simplification,
  4132     not just from left to right. The simplifier now preserves
  4133     the order of assumptions.
  4134 
  4135     Potential INCOMPATIBILITY:
  4136 
  4137     -- simp sometimes diverges where the old version did
  4138        not, e.g. invoking simp on the goal
  4139 
  4140         [| P (f x); y = x; f x = f y |] ==> Q
  4141 
  4142        now gives rise to the infinite reduction sequence
  4143 
  4144         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4145 
  4146        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4147        kind of problem.
  4148 
  4149     -- Tactics combining classical reasoner and simplification (such as auto)
  4150        are also affected by this change, because many of them rely on
  4151        simp. They may sometimes diverge as well or yield a different numbers
  4152        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4153        in case of problems. Sometimes subsequent calls to the classical
  4154        reasoner will fail because a preceeding call to the simplifier too
  4155        eagerly simplified the goal, e.g. deleted redundant premises.
  4156 
  4157   - The simplifier trace now shows the names of the applied rewrite rules
  4158 
  4159   - You can limit the number of recursive invocations of the simplifier
  4160     during conditional rewriting (where the simplifie tries to solve the
  4161     conditions before applying the rewrite rule):
  4162     ML "simp_depth_limit := n"
  4163     where n is an integer. Thus you can force termination where previously
  4164     the simplifier would diverge.
  4165 
  4166   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4167 
  4168   - No longer aborts on failed congruence proof.  Instead, the
  4169     congruence is ignored.
  4170 
  4171 * Pure: New generic framework for extracting programs from constructive
  4172   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4173   as HOL/Extraction for some case studies.
  4174 
  4175 * Pure: The main goal of the proof state is no longer shown by default, only
  4176 the subgoals. This behaviour is controlled by a new flag.
  4177    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4178 (ML: Proof.show_main_goal).
  4179 
  4180 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4181 rules whose conclusion matches subgoal 1:
  4182       PG menu: Isabelle/Isar -> Show me -> matching rules
  4183 The rules are ordered by how closely they match the subgoal.
  4184 In particular, rules that solve a subgoal outright are displayed first
  4185 (or rather last, the way they are printed).
  4186 (ML: ProofGeneral.print_intros())
  4187 
  4188 * Pure: New flag trace_unify_fail causes unification to print
  4189 diagnostic information (PG: in trace buffer) when it fails. This is
  4190 useful for figuring out why single step proofs like rule, erule or
  4191 assumption failed.
  4192 
  4193 * Pure: Locale specifications now produce predicate definitions
  4194 according to the body of text (covering assumptions modulo local
  4195 definitions); predicate "loc_axioms" covers newly introduced text,
  4196 while "loc" is cumulative wrt. all included locale expressions; the
  4197 latter view is presented only on export into the global theory
  4198 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4199 on the old view without predicates;
  4200 
  4201 * Pure: predefined locales "var" and "struct" are useful for sharing
  4202 parameters (as in CASL, for example); just specify something like
  4203 ``var x + var y + struct M'' as import;
  4204 
  4205 * Pure: improved thms_containing: proper indexing of facts instead of
  4206 raw theorems; check validity of results wrt. current name space;
  4207 include local facts of proof configuration (also covers active
  4208 locales), cover fixed variables in index; may use "_" in term
  4209 specification; an optional limit for the number of printed facts may
  4210 be given (the default is 40);
  4211 
  4212 * Pure: disallow duplicate fact bindings within new-style theory files
  4213 (batch-mode only);
  4214 
  4215 * Provers: improved induct method: assumptions introduced by case
  4216 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4217 the goal statement); "foo" still refers to all facts collectively;
  4218 
  4219 * Provers: the function blast.overloaded has been removed: all constants
  4220 are regarded as potentially overloaded, which improves robustness in exchange
  4221 for slight decrease in efficiency;
  4222 
  4223 * Provers/linorder: New generic prover for transitivity reasoning over
  4224 linear orders.  Note: this prover is not efficient!
  4225 
  4226 * Isar: preview of problems to finish 'show' now produce an error
  4227 rather than just a warning (in interactive mode);
  4228 
  4229 
  4230 *** HOL ***
  4231 
  4232 * arith(_tac)
  4233 
  4234  - Produces a counter example if it cannot prove a goal.
  4235    Note that the counter example may be spurious if the goal is not a formula
  4236    of quantifier-free linear arithmetic.
  4237    In ProofGeneral the counter example appears in the trace buffer.
  4238 
  4239  - Knows about div k and mod k where k is a numeral of type nat or int.
  4240 
  4241  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4242    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4243    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4244 
  4245 * simp's arithmetic capabilities have been enhanced a bit: it now
  4246 takes ~= in premises into account (by performing a case split);
  4247 
  4248 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4249 are distributed over a sum of terms;
  4250 
  4251 * New tactic "trans_tac" and method "trans" instantiate
  4252 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4253 "<=", "<" and "=").
  4254 
  4255 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4256 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4257 
  4258 * 'typedef' command has new option "open" to suppress the set
  4259 definition;
  4260 
  4261 * functions Min and Max on finite sets have been introduced (theory
  4262 Finite_Set);
  4263 
  4264 * attribute [symmetric] now works for relations as well; it turns
  4265 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4266 
  4267 * induct over a !!-quantified statement (say !!x1..xn):
  4268   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4269 
  4270 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4271 %x. None. Warning: empty_def now refers to the previously hidden definition
  4272 of the empty set.
  4273 
  4274 * Algebra: formalization of classical algebra.  Intended as base for
  4275 any algebraic development in Isabelle.  Currently covers group theory
  4276 (up to Sylow's theorem) and ring theory (Universal Property of
  4277 Univariate Polynomials).  Contributions welcome;
  4278 
  4279 * GroupTheory: deleted, since its material has been moved to Algebra;
  4280 
  4281 * Complex: new directory of the complex numbers with numeric constants,
  4282 nonstandard complex numbers, and some complex analysis, standard and
  4283 nonstandard (Jacques Fleuriot);
  4284 
  4285 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4286 
  4287 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4288 Fleuriot);
  4289 
  4290 * Real/HahnBanach: updated and adapted to locales;
  4291 
  4292 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4293 Gray and Kramer);
  4294 
  4295 * UNITY: added the Meier-Sanders theory of progress sets;
  4296 
  4297 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4298 as abstract algorithms, instantiated to the JVM;
  4299 
  4300 * Bali: Java source language formalization. Type system, operational
  4301 semantics, axiomatic semantics. Supported language features:
  4302 classes, interfaces, objects,virtual methods, static methods,
  4303 static/instance fields, arrays, access modifiers, definite
  4304 assignment, exceptions.
  4305 
  4306 
  4307 *** ZF ***
  4308 
  4309 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4310 universe, etc.);
  4311 
  4312 * Main ZF: virtually all theories converted to new-style format;
  4313 
  4314 
  4315 *** ML ***
  4316 
  4317 * Pure: Tactic.prove provides sane interface for internal proofs;
  4318 omits the infamous "standard" operation, so this is more appropriate
  4319 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4320 
  4321 * Pure: improved error reporting of simprocs;
  4322 
  4323 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4324 up simprocs;
  4325 
  4326 
  4327 *** Document preparation ***
  4328 
  4329 * uses \par instead of \\ for line breaks in theory text. This may
  4330 shift some page breaks in large documents. To get the old behaviour
  4331 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4332 
  4333 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4334 other packages
  4335 
  4336 * \<euro> now needs package babel/greek instead of marvosym (which
  4337 broke \Rightarrow)
  4338 
  4339 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4340 textcomp package)
  4341 
  4342 
  4343 
  4344 New in Isabelle2002 (March 2002)
  4345 --------------------------------
  4346 
  4347 *** Document preparation ***
  4348 
  4349 * greatly simplified document preparation setup, including more
  4350 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4351 instructive isatool mkdir; users should basically be able to get
  4352 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4353 users may run a separate document processing stage manually like this:
  4354 "isatool usedir -D output HOL Test && isatool document Test/output";
  4355 
  4356 * theory dependency graph may now be incorporated into documents;
  4357 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4358 with \includegraphics of LaTeX;
  4359 
  4360 * proper spacing of consecutive markup elements, especially text
  4361 blocks after section headings;
  4362 
  4363 * support bold style (for single symbols only), input syntax is like
  4364 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4365 
  4366 * \<bullet> is now output as bold \cdot by default, which looks much
  4367 better in printed text;
  4368 
  4369 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4370 note that these symbols are currently unavailable in Proof General /
  4371 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4372 
  4373 * isatool latex no longer depends on changed TEXINPUTS, instead
  4374 isatool document copies the Isabelle style files to the target
  4375 location;
  4376 
  4377 
  4378 *** Isar ***
  4379 
  4380 * Pure/Provers: improved proof by cases and induction;
  4381   - 'case' command admits impromptu naming of parameters (such as
  4382     "case (Suc n)");
  4383   - 'induct' method divinates rule instantiation from the inductive
  4384     claim; no longer requires excessive ?P bindings for proper
  4385     instantiation of cases;
  4386   - 'induct' method properly enumerates all possibilities of set/type
  4387     rules; as a consequence facts may be also passed through *type*
  4388     rules without further ado;
  4389   - 'induct' method now derives symbolic cases from the *rulified*
  4390     rule (before it used to rulify cases stemming from the internal
  4391     atomized version); this means that the context of a non-atomic
  4392     statement becomes is included in the hypothesis, avoiding the
  4393     slightly cumbersome show "PROP ?case" form;
  4394   - 'induct' may now use elim-style induction rules without chaining
  4395     facts, using ``missing'' premises from the goal state; this allows
  4396     rules stemming from inductive sets to be applied in unstructured
  4397     scripts, while still benefitting from proper handling of non-atomic
  4398     statements; NB: major inductive premises need to be put first, all
  4399     the rest of the goal is passed through the induction;
  4400   - 'induct' proper support for mutual induction involving non-atomic
  4401     rule statements (uses the new concept of simultaneous goals, see
  4402     below);
  4403   - append all possible rule selections, but only use the first
  4404     success (no backtracking);
  4405   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4406   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4407   - added 'print_induct_rules' (covered by help item in recent Proof
  4408     General versions);
  4409   - moved induct/cases attributes to Pure, methods to Provers;
  4410   - generic method setup instantiated for FOL and HOL;
  4411 
  4412 * Pure: support multiple simultaneous goal statements, for example
  4413 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4414 meta-level mechanism, this acts as if several individual goals had
  4415 been stated separately; in particular common proof methods need to be
  4416 repeated in order to cover all claims; note that a single elimination
  4417 step is *not* sufficient to establish the two conjunctions, so this
  4418 fails:
  4419 
  4420   assume "A & B" then have A and B ..   (*".." fails*)
  4421 
  4422 better use "obtain" in situations as above; alternative refer to
  4423 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4424 
  4425 * Pure: proper integration with ``locales''; unlike the original
  4426 version by Florian Kammller, Isar locales package high-level proof
  4427 contexts rather than raw logical ones (e.g. we admit to include
  4428 attributes everywhere); operations on locales include merge and
  4429 rename; support for implicit arguments (``structures''); simultaneous
  4430 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4431 some examples;
  4432 
  4433 * Pure: the following commands have been ``localized'', supporting a
  4434 target locale specification "(in name)": 'lemma', 'theorem',
  4435 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4436 stored both within the locale and at the theory level (exported and
  4437 qualified by the locale name);
  4438 
  4439 * Pure: theory goals may now be specified in ``long'' form, with
  4440 ad-hoc contexts consisting of arbitrary locale elements. for example
  4441 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4442 definitions may be given, too); the result is a meta-level rule with
  4443 the context elements being discharged in the obvious way;
  4444 
  4445 * Pure: new proof command 'using' allows to augment currently used
  4446 facts after a goal statement ('using' is syntactically analogous to
  4447 'apply', but acts on the goal's facts only); this allows chained facts
  4448 to be separated into parts given before and after a claim, as in
  4449 ``from a and b have C using d and e <proof>'';
  4450 
  4451 * Pure: renamed "antecedent" case to "rule_context";
  4452 
  4453 * Pure: new 'judgment' command records explicit information about the
  4454 object-logic embedding (used by several tools internally); no longer
  4455 use hard-wired "Trueprop";
  4456 
  4457 * Pure: added 'corollary' command;
  4458 
  4459 * Pure: fixed 'token_translation' command;
  4460 
  4461 * Pure: removed obsolete 'exported' attribute;
  4462 
  4463 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4464 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4465 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4466 
  4467 * Pure: method 'atomize' presents local goal premises as object-level
  4468 statements (atomic meta-level propositions); setup controlled via
  4469 rewrite rules declarations of 'atomize' attribute; example
  4470 application: 'induct' method with proper rule statements in improper
  4471 proof *scripts*;
  4472 
  4473 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4474 now consider the syntactic context of assumptions, giving a better
  4475 chance to get type-inference of the arguments right (this is
  4476 especially important for locales);
  4477 
  4478 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4479 mode;
  4480 
  4481 * Pure/obtain: the formal conclusion "thesis", being marked as
  4482 ``internal'', may no longer be reference directly in the text;
  4483 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4484 situations;
  4485 
  4486 * Pure: generic 'sym' attribute which declares a rule both as pure
  4487 'elim?' and for the 'symmetric' operation;
  4488 
  4489 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4490 text; the fixed correlation with particular command syntax has been
  4491 discontinued;
  4492 
  4493 * Pure: new method 'rules' is particularly well-suited for proof
  4494 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4495 but often produces more compact proof terms with less detours;
  4496 
  4497 * Pure/Provers/classical: simplified integration with pure rule
  4498 attributes and methods; the classical "intro?/elim?/dest?"
  4499 declarations coincide with the pure ones; the "rule" method no longer
  4500 includes classically swapped intros; "intro" and "elim" methods no
  4501 longer pick rules from the context; also got rid of ML declarations
  4502 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4503 INCOMPATIBILITY;
  4504 
  4505 * Provers/classical: attribute 'swapped' produces classical inversions
  4506 of introduction rules;
  4507 
  4508 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4509 rules instead of full simplifier context; 'iff' attribute handles
  4510 conditional rules;
  4511 
  4512 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4513 
  4514 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4515 "(permissive)" option to recover old behavior;
  4516 
  4517 * HOL: 'inductive' no longer features separate (collective) attributes
  4518 for 'intros' (was found too confusing);
  4519 
  4520 * HOL: properly declared induction rules less_induct and
  4521 wf_induct_rule;
  4522 
  4523 
  4524 *** HOL ***
  4525 
  4526 * HOL: moved over to sane numeral syntax; the new policy is as
  4527 follows:
  4528 
  4529   - 0 and 1 are polymorphic constants, which are defined on any
  4530   numeric type (nat, int, real etc.);
  4531 
  4532   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4533   binary representation internally;
  4534 
  4535   - type nat has special constructor Suc, and generally prefers Suc 0
  4536   over 1::nat and Suc (Suc 0) over 2::nat;
  4537 
  4538 This change may cause significant problems of INCOMPATIBILITY; here
  4539 are some hints on converting existing sources:
  4540 
  4541   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4542   entities, so expressions involving "-" (unary or binary minus) need
  4543   to be spaced properly;
  4544 
  4545   - existing occurrences of "1" may need to be constraint "1::nat" or
  4546   even replaced by Suc 0; similar for old "2";
  4547 
  4548   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4549 
  4550   - remove all special provisions on numerals in proofs;
  4551 
  4552 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4553 representation (depends on bin_arith_simps in the default context);
  4554 
  4555 * HOL: symbolic syntax for x^2 (numeral 2);
  4556 
  4557 * HOL: the class of all HOL types is now called "type" rather than
  4558 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4559 in axclass/classes, instance/arities, and (usually rare) occurrences
  4560 in typings (of consts etc.); internally the class is called
  4561 "HOL.type", ML programs should refer to HOLogic.typeS;
  4562 
  4563 * HOL/record package improvements:
  4564   - new derived operations "fields" to build a partial record section,
  4565     "extend" to promote a fixed record to a record scheme, and
  4566     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4567     declared as simp by default;
  4568   - shared operations ("more", "fields", etc.) now need to be always
  4569     qualified) --- potential INCOMPATIBILITY;
  4570   - removed "make_scheme" operations (use "make" with "extend") --
  4571     INCOMPATIBILITY;
  4572   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4573   - provides cases/induct rules for use with corresponding Isar
  4574     methods (for concrete records, record schemes, concrete more
  4575     parts, and schematic more parts -- in that order);
  4576   - internal definitions directly based on a light-weight abstract
  4577     theory of product types over typedef rather than datatype;
  4578 
  4579 * HOL: generic code generator for generating executable ML code from
  4580 specifications; specific support for HOL constructs such as inductive
  4581 datatypes and sets, as well as recursive functions; can be invoked
  4582 via 'generate_code' theory section;
  4583 
  4584 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4585 
  4586 * HOL: consolidated and renamed several theories.  In particular:
  4587         Ord.thy has been absorbed into HOL.thy
  4588         String.thy has been absorbed into List.thy
  4589 
  4590 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4591 (beware of argument permutation!);
  4592 
  4593 * HOL: linorder_less_split superseded by linorder_cases;
  4594 
  4595 * HOL/List: "nodups" renamed to "distinct";
  4596 
  4597 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4598 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4599   - Ex_def has changed, now need to use some_eq_ex
  4600 
  4601 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4602 in this (rare) case use:
  4603 
  4604   delSWrapper "split_all_tac"
  4605   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4606 
  4607 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4608 MAY FAIL;
  4609 
  4610 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4611 Isabelle's type classes, ^ on functions and relations has too general
  4612 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4613 necessary to attach explicit type constraints;
  4614 
  4615 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4616 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4617 renamed accordingly (eg "compI" -> "rel_compI").
  4618 
  4619 * HOL: syntax translations now work properly with numerals and records
  4620 expressions;
  4621 
  4622 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4623 of "lam" -- INCOMPATIBILITY;
  4624 
  4625 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4626 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4627 renamed "Product_Type.unit";
  4628 
  4629 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4630 
  4631 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4632 the "cases" method);
  4633 
  4634 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4635 Florian Kammller);
  4636 
  4637 * HOL/IMP: updated and converted to new-style theory format; several
  4638 parts turned into readable document, with proper Isar proof texts and
  4639 some explanations (by Gerwin Klein);
  4640 
  4641 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4642 
  4643 * HOL-Hyperreal is now a logic image;
  4644 
  4645 
  4646 *** HOLCF ***
  4647 
  4648 * Isar: consts/constdefs supports mixfix syntax for continuous
  4649 operations;
  4650 
  4651 * Isar: domain package adapted to new-style theory format, e.g. see
  4652 HOLCF/ex/Dnat.thy;
  4653 
  4654 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4655 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4656 lift.induct_tac, always use UU instead of Undef;
  4657 
  4658 * HOLCF/IMP: updated and converted to new-style theory;
  4659 
  4660 
  4661 *** ZF ***
  4662 
  4663 * Isar: proper integration of logic-specific tools and packages,
  4664 including theory commands '(co)inductive', '(co)datatype',
  4665 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4666 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4667 
  4668 * theory Main no longer includes AC; for the Axiom of Choice, base
  4669 your theory on Main_ZFC;
  4670 
  4671 * the integer library now covers quotients and remainders, with many
  4672 laws relating division to addition, multiplication, etc.;
  4673 
  4674 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4675 typeless version of the formalism;
  4676 
  4677 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4678 format;
  4679 
  4680 * ZF/Induct: new directory for examples of inductive definitions,
  4681 including theory Multiset for multiset orderings; converted to
  4682 new-style theory format;
  4683 
  4684 * ZF: many new theorems about lists, ordinals, etc.;
  4685 
  4686 
  4687 *** General ***
  4688 
  4689 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4690 variable proof controls level of detail: 0 = no proofs (only oracle
  4691 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4692 also ref manual for further ML interfaces;
  4693 
  4694 * Pure/axclass: removed obsolete ML interface
  4695 goal_subclass/goal_arity;
  4696 
  4697 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4698 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4699 separate tokens, so expressions involving minus need to be spaced
  4700 properly;
  4701 
  4702 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4703 rather than "infixl" or "infixr";
  4704 
  4705 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4706 sort constraint specifications in type inference; e.g. "x::_::foo"
  4707 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4708 type variable);
  4709 
  4710 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4711 control output of nested => (types); the default behavior is
  4712 "type_brackets";
  4713 
  4714 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4715 tokens into AST constants;
  4716 
  4717 * Pure/syntax: prefer later declarations of translations and print
  4718 translation functions; potential INCOMPATIBILITY: need to reverse
  4719 multiple declarations for same syntax element constant;
  4720 
  4721 * Pure/show_hyps reset by default (in accordance to existing Isar
  4722 practice);
  4723 
  4724 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4725 addSafter;
  4726 
  4727 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4728 as well;
  4729 
  4730 * system: tested support for MacOS X; should be able to get Isabelle +
  4731 Proof General to work in a plain Terminal after installing Poly/ML
  4732 (e.g. from the Isabelle distribution area) and GNU bash alone
  4733 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4734 support requires further installations, e.g. from
  4735 http://fink.sourceforge.net/);
  4736 
  4737 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4738 
  4739 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4740 of 40 MB), cf. ML_OPTIONS;
  4741 
  4742 * system: Proof General keywords specification is now part of the
  4743 Isabelle distribution (see etc/isar-keywords.el);
  4744 
  4745 * system: support for persistent Proof General sessions (refrain from
  4746 outdating all loaded theories on startup); user may create writable
  4747 logic images like this: ``isabelle -q HOL Test'';
  4748 
  4749 * system: smart selection of Isabelle process versus Isabelle
  4750 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4751 run both "isabelle" and "Isabelle" even if file names are badly
  4752 damaged (executable inspects the case of the first letter of its own
  4753 name); added separate "isabelle-process" and "isabelle-interface";
  4754 
  4755 * system: refrain from any attempt at filtering input streams; no
  4756 longer support ``8bit'' encoding of old isabelle font, instead proper
  4757 iso-latin characters may now be used; the related isatools
  4758 "symbolinput" and "nonascii" have disappeared as well;
  4759 
  4760 * system: removed old "xterm" interface (the print modes "xterm" and
  4761 "xterm_color" are still available for direct use in a suitable
  4762 terminal);
  4763 
  4764 
  4765 
  4766 New in Isabelle99-2 (February 2001)
  4767 -----------------------------------
  4768 
  4769 *** Overview of INCOMPATIBILITIES ***
  4770 
  4771 * HOL: please note that theories in the Library and elsewhere often use the
  4772 new-style (Isar) format; to refer to their theorems in an ML script you must
  4773 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4774 
  4775 * HOL: inductive package no longer splits induction rule aggressively,
  4776 but only as far as specified by the introductions given; the old
  4777 format may be recovered via ML function complete_split_rule or attribute
  4778 'split_rule (complete)';
  4779 
  4780 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4781 gfp_Tarski to gfp_unfold;
  4782 
  4783 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4784 
  4785 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4786 relation); infix "^^" has been renamed "``"; infix "``" has been
  4787 renamed "`"; "univalent" has been renamed "single_valued";
  4788 
  4789 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4790 operation;
  4791 
  4792 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4793 
  4794 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4795 
  4796 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4797 consequence, it is no longer monotonic wrt. the local goal context
  4798 (which is now passed through the inductive cases);
  4799 
  4800 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4801 \<gg> to \<ggreater>;
  4802 
  4803 
  4804 *** Document preparation ***
  4805 
  4806 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4807 available: are "it" for near math-mode best-style output, "sl" for
  4808 slanted text style, and "tt" for plain type-writer; if no
  4809 \isabellestyle command is given, output is according to slanted
  4810 type-writer);
  4811 
  4812 * support sub/super scripts (for single symbols only), input syntax is
  4813 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4814 
  4815 * some more standard symbols; see Appendix A of the system manual for
  4816 the complete list of symbols defined in isabellesym.sty;
  4817 
  4818 * improved isabelle style files; more abstract symbol implementation
  4819 (should now use \isamath{...} and \isatext{...} in custom symbol
  4820 definitions);
  4821 
  4822 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4823 state; Note that presentation of goal states does not conform to
  4824 actual human-readable proof documents.  Please do not include goal
  4825 states into document output unless you really know what you are doing!
  4826 
  4827 * proper indentation of antiquoted output with proportional LaTeX
  4828 fonts;
  4829 
  4830 * no_document ML operator temporarily disables LaTeX document
  4831 generation;
  4832 
  4833 * isatool unsymbolize tunes sources for plain ASCII communication;
  4834 
  4835 
  4836 *** Isar ***
  4837 
  4838 * Pure: Isar now suffers initial goal statements to contain unbound
  4839 schematic variables (this does not conform to actual readable proof
  4840 documents, due to unpredictable outcome and non-compositional proof
  4841 checking); users who know what they are doing may use schematic goals
  4842 for Prolog-style synthesis of proven results;
  4843 
  4844 * Pure: assumption method (an implicit finishing) now handles actual
  4845 rules as well;
  4846 
  4847 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4848 initial goal, declare "that" only as Pure intro (only for single
  4849 steps); the "that" rule assumption may now be involved in implicit
  4850 finishing, thus ".." becomes a feasible for trivial obtains;
  4851 
  4852 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4853 instance proofs may be performed by "..";
  4854 
  4855 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4856 statements as well;
  4857 
  4858 * Pure: more robust selection of calculational rules;
  4859 
  4860 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4861 rule (as well as the assumption rule);
  4862 
  4863 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4864 lemmas, using the graph browser tool;
  4865 
  4866 * Pure: predict failure of "show" in interactive mode;
  4867 
  4868 * Pure: 'thms_containing' now takes actual terms as arguments;
  4869 
  4870 * HOL: improved method 'induct' --- now handles non-atomic goals
  4871 (potential INCOMPATIBILITY); tuned error handling;
  4872 
  4873 * HOL: cases and induct rules now provide explicit hints about the
  4874 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4875 any remaining facts are inserted into the goal verbatim;
  4876 
  4877 * HOL: local contexts (aka cases) may now contain term bindings as
  4878 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4879 the result to be shown in each case;
  4880 
  4881 * HOL: added 'recdef_tc' command;
  4882 
  4883 * isatool convert assists in eliminating legacy ML scripts;
  4884 
  4885 
  4886 *** HOL ***
  4887 
  4888 * HOL/Library: a collection of generic theories to be used together
  4889 with main HOL; the theory loader path already includes this directory
  4890 by default; the following existing theories have been moved here:
  4891 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4892 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4893 
  4894 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4895 modelling and verification task performed in Isabelle/HOL +
  4896 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4897 
  4898 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4899 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4900 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4901 'domain', this makes the theory consistent with mathematical
  4902 literature;
  4903 
  4904 * HOL basics: added overloaded operations "inverse" and "divide"
  4905 (infix "/"), syntax for generic "abs" operation, generic summation
  4906 operator \<Sum>;
  4907 
  4908 * HOL/typedef: simplified package, provide more useful rules (see also
  4909 HOL/subset.thy);
  4910 
  4911 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4912 now expressed as a proper nested rule (old-style tactic scripts may
  4913 require atomize_strip_tac to cope with non-atomic premises);
  4914 
  4915 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4916 to "split_conv" (old name still available for compatibility);
  4917 
  4918 * HOL: improved concrete syntax for strings (e.g. allows translation
  4919 rules with string literals);
  4920 
  4921 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  4922  and Fleuriot's mechanization of analysis, including the transcendental
  4923  functions for the reals;
  4924 
  4925 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  4926 
  4927 
  4928 *** CTT ***
  4929 
  4930 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  4931 "lam" is displayed as TWO lambda-symbols
  4932 
  4933 * CTT: theory Main now available, containing everything (that is, Bool
  4934 and Arith);
  4935 
  4936 
  4937 *** General ***
  4938 
  4939 * Pure: the Simplifier has been implemented properly as a derived rule
  4940 outside of the actual kernel (at last!); the overall performance
  4941 penalty in practical applications is about 50%, while reliability of
  4942 the Isabelle inference kernel has been greatly improved;
  4943 
  4944 * print modes "brackets" and "no_brackets" control output of nested =>
  4945 (types) and ==> (props); the default behaviour is "brackets";
  4946 
  4947 * Provers: fast_tac (and friends) now handle actual object-logic rules
  4948 as assumptions as well;
  4949 
  4950 * system: support Poly/ML 4.0;
  4951 
  4952 * system: isatool install handles KDE version 1 or 2;
  4953 
  4954 
  4955 
  4956 New in Isabelle99-1 (October 2000)
  4957 ----------------------------------
  4958 
  4959 *** Overview of INCOMPATIBILITIES ***
  4960 
  4961 * HOL: simplification of natural numbers is much changed; to partly
  4962 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  4963 issue the following ML commands:
  4964 
  4965   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  4966   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  4967 
  4968 * HOL: simplification no longer dives into case-expressions; this is
  4969 controlled by "t.weak_case_cong" for each datatype t;
  4970 
  4971 * HOL: nat_less_induct renamed to less_induct;
  4972 
  4973 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  4974 fixsome to patch .thy and .ML sources automatically;
  4975 
  4976   select_equality  -> some_equality
  4977   select_eq_Ex     -> some_eq_ex
  4978   selectI2EX       -> someI2_ex
  4979   selectI2         -> someI2
  4980   selectI          -> someI
  4981   select1_equality -> some1_equality
  4982   Eps_sym_eq       -> some_sym_eq_trivial
  4983   Eps_eq           -> some_eq_trivial
  4984 
  4985 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  4986 
  4987 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  4988 instead);
  4989 
  4990 * HOL: the recursion equations generated by 'recdef' are now called
  4991 f.simps instead of f.rules;
  4992 
  4993 * HOL: qed_spec_mp now also handles bounded ALL as well;
  4994 
  4995 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  4996 sometimes be needed;
  4997 
  4998 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  4999 
  5000 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5001 
  5002 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5003 product is now "<*>" instead of "Times"; the lexicographic product is
  5004 now "<*lex*>" instead of "**";
  5005 
  5006 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5007 of main HOL, but was unused); better use HOL's datatype package;
  5008 
  5009 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5010 the old syntax may be recovered as follows:
  5011 
  5012   syntax (symbols)
  5013     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5014       (infixl "\\<oplus>" 100)
  5015 
  5016 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5017 
  5018 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5019 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5020 internally;
  5021 
  5022 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5023 changed from A/r to A//r;
  5024 
  5025 * ZF: new treatment of arithmetic (nat & int) may break some old
  5026 proofs;
  5027 
  5028 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5029 rulify -> rule_format, elimify -> elim_format, ...);
  5030 
  5031 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5032 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5033 should have to change intro!! to intro? only); replaced "delrule" by
  5034 "rule del";
  5035 
  5036 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5037 
  5038 * Provers: strengthened force_tac by using new first_best_tac;
  5039 
  5040 * LaTeX document preparation: several changes of isabelle.sty (see
  5041 lib/texinputs);
  5042 
  5043 
  5044 *** Document preparation ***
  5045 
  5046 * formal comments (text blocks etc.) in new-style theories may now
  5047 contain antiquotations of thm/prop/term/typ/text to be presented
  5048 according to latex print mode; concrete syntax is like this:
  5049 @{term[show_types] "f(x) = a + x"};
  5050 
  5051 * isatool mkdir provides easy setup of Isabelle session directories,
  5052 including proper document sources;
  5053 
  5054 * generated LaTeX sources are now deleted after successful run
  5055 (isatool document -c); may retain a copy somewhere else via -D option
  5056 of isatool usedir;
  5057 
  5058 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5059 style files, achieving self-contained LaTeX sources and simplifying
  5060 LaTeX debugging;
  5061 
  5062 * old-style theories now produce (crude) LaTeX output as well;
  5063 
  5064 * browser info session directories are now self-contained (may be put
  5065 on WWW server seperately); improved graphs of nested sessions; removed
  5066 graph for 'all sessions';
  5067 
  5068 * several improvements in isabelle style files; \isabellestyle{it}
  5069 produces fake math mode output; \isamarkupheader is now \section by
  5070 default; see lib/texinputs/isabelle.sty etc.;
  5071 
  5072 
  5073 *** Isar ***
  5074 
  5075 * Isar/Pure: local results and corresponding term bindings are now
  5076 subject to Hindley-Milner polymorphism (similar to ML); this
  5077 accommodates incremental type-inference very nicely;
  5078 
  5079 * Isar/Pure: new derived language element 'obtain' supports
  5080 generalized existence reasoning;
  5081 
  5082 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5083 support accumulation of results, without applying any rules yet;
  5084 useful to collect intermediate results without explicit name
  5085 references, and for use with transitivity rules with more than 2
  5086 premises;
  5087 
  5088 * Isar/Pure: scalable support for case-analysis type proofs: new
  5089 'case' language element refers to local contexts symbolically, as
  5090 produced by certain proof methods; internally, case names are attached
  5091 to theorems as "tags";
  5092 
  5093 * Isar/Pure: theory command 'hide' removes declarations from
  5094 class/type/const name spaces;
  5095 
  5096 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5097 indicate potential overloading;
  5098 
  5099 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5100 
  5101 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5102 "{a,b,c}" instead of {a,b,c};
  5103 
  5104 * Isar/Pure now provides its own version of intro/elim/dest
  5105 attributes; useful for building new logics, but beware of confusion
  5106 with the version in Provers/classical;
  5107 
  5108 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5109 case name 'antecedent';
  5110 
  5111 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5112 to the current context is now done automatically);
  5113 
  5114 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5115 for definining proof methods in ML;
  5116 
  5117 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5118 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5119 most cases, one should have to change intro!! to intro? only);
  5120 replaced "delrule" by "rule del";
  5121 
  5122 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5123 'symmetric' attribute (the latter supercedes [RS sym]);
  5124 
  5125 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5126 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5127 well (including splits);
  5128 
  5129 * Isar/Provers: Simplifier and Classical methods now support all kind
  5130 of modifiers used in the past, including 'cong', 'iff', etc.
  5131 
  5132 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5133 of Simplifier and Classical reasoner);
  5134 
  5135 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5136 now support named cases; major packages (inductive, datatype, primrec,
  5137 recdef) support case names and properly name parameters;
  5138 
  5139 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5140 monotonicity conditions are extracted to be proven at end of
  5141 calculations;
  5142 
  5143 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5144 method anyway;
  5145 
  5146 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5147 split_if split_if_asm; datatype package provides theorems foo.splits =
  5148 foo.split foo.split_asm for each datatype;
  5149 
  5150 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5151 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5152 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5153 use "(cases (simplified))" method in proper proof texts);
  5154 
  5155 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5156 
  5157 * Isar: names of theorems etc. may be natural numbers as well;
  5158 
  5159 * Isar: 'pr' command: optional arguments for goals_limit and
  5160 ProofContext.prems_limit; no longer prints theory contexts, but only
  5161 proof states;
  5162 
  5163 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5164 additional print modes to be specified; e.g. "pr(latex)" will print
  5165 proof state according to the Isabelle LaTeX style;
  5166 
  5167 * Isar: improved support for emulating tactic scripts, including proof
  5168 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5169 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5170 (for HOL datatypes);
  5171 
  5172 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5173 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5174 'proof method scripts' have to be in depth-first order;
  5175 
  5176 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5177 
  5178 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5179 should instead use individual commands for printing items
  5180 (print_commands, print_methods etc.);
  5181 
  5182 * Isar: added 'nothing' --- the empty list of theorems;
  5183 
  5184 
  5185 *** HOL ***
  5186 
  5187 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5188 corresponding virtual machine and a specification of its bytecode
  5189 verifier and a lightweight bytecode verifier, including proofs of
  5190 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5191 Cornelia Pusch (see also the homepage of project Bali at
  5192 http://isabelle.in.tum.de/Bali/);
  5193 
  5194 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5195 Clemens Ballarin;
  5196 
  5197 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5198 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5199 Rasmussen;
  5200 
  5201 * HOL/Lattice: fundamental concepts of lattice theory and order
  5202 structures, including duals, properties of bounds versus algebraic
  5203 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5204 Theorem for complete lattices etc.; may also serve as a demonstration
  5205 for abstract algebraic reasoning using axiomatic type classes, and
  5206 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5207 
  5208 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5209 von Oheimb;
  5210 
  5211 * HOL/IMPP: extension of IMP with local variables and mutually
  5212 recursive procedures, by David von Oheimb;
  5213 
  5214 * HOL/Lambda: converted into new-style theory and document;
  5215 
  5216 * HOL/ex/Multiquote: example of multiple nested quotations and
  5217 anti-quotations -- basically a generalized version of de-Bruijn
  5218 representation; very useful in avoiding lifting of operations;
  5219 
  5220 * HOL/record: added general record equality rule to simpset; fixed
  5221 select-update simplification procedure to handle extended records as
  5222 well; admit "r" as field name;
  5223 
  5224 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5225 other numeric types and also as the identity of groups, rings, etc.;
  5226 
  5227 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5228 Types nat and int belong to this axclass;
  5229 
  5230 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5231    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5232    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5233   two terms #m*u and #n*u are replaced by #(m+n)*u
  5234     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5235   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5236     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5237 
  5238 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5239 powerful prover for predicate logic but knows nothing of clasets; see
  5240 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5241 
  5242 * HOL: new version of "case_tac" subsumes both boolean case split and
  5243 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5244 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5245 
  5246 * HOL: simplification no longer dives into case-expressions: only the
  5247 selector expression is simplified, but not the remaining arms; to
  5248 enable full simplification of case-expressions for datatype t, you may
  5249 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5250 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5251 
  5252 * HOL/recdef: the recursion equations generated by 'recdef' for
  5253 function 'f' are now called f.simps instead of f.rules; if all
  5254 termination conditions are proved automatically, these simplification
  5255 rules are added to the simpset, as in primrec; rules may be named
  5256 individually as well, resulting in a separate list of theorems for
  5257 each equation;
  5258 
  5259 * HOL/While is a new theory that provides a while-combinator. It
  5260 permits the definition of tail-recursive functions without the
  5261 provision of a termination measure. The latter is necessary once the
  5262 invariant proof rule for while is applied.
  5263 
  5264 * HOL: new (overloaded) notation for the set of elements below/above
  5265 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5266 
  5267 * HOL: theorems impI, allI, ballI bound as "strip";
  5268 
  5269 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5270 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5271 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5272 
  5273 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5274 
  5275 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5276 main HOL, but was unused);
  5277 
  5278 * HOL: fewer consts declared as global (e.g. have to refer to
  5279 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5280 
  5281 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5282 in case of overlap with user translations (e.g. judgements over
  5283 tuples); (note that the underlying logical represenation is still
  5284 bogus);
  5285 
  5286 
  5287 *** ZF ***
  5288 
  5289 * ZF: simplification automatically cancels common terms in arithmetic
  5290 expressions over nat and int;
  5291 
  5292 * ZF: new treatment of nat to minimize type-checking: all operators
  5293 coerce their operands to a natural number using the function natify,
  5294 making the algebraic laws unconditional;
  5295 
  5296 * ZF: as above, for int: operators coerce their operands to an integer
  5297 using the function intify;
  5298 
  5299 * ZF: the integer library now contains many of the usual laws for the
  5300 orderings, including $<=, and monotonicity laws for $+ and $*;
  5301 
  5302 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5303 simplification;
  5304 
  5305 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5306 to the simplifier and classical reasoner simultaneously;
  5307 
  5308 
  5309 *** General ***
  5310 
  5311 * Provers: blast_tac now handles actual object-logic rules as
  5312 assumptions; note that auto_tac uses blast_tac internally as well;
  5313 
  5314 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5315 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5316 
  5317 * Provers: delrules now handles destruct rules as well (no longer need
  5318 explicit make_elim);
  5319 
  5320 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5321   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5322 use instead the strong form,
  5323   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5324 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5325 from destruct-rules;
  5326 
  5327 * Provers: Simplifier.easy_setup provides a fast path to basic
  5328 Simplifier setup for new object-logics;
  5329 
  5330 * Pure: AST translation rules no longer require constant head on LHS;
  5331 
  5332 * Pure: improved name spaces: ambiguous output is qualified; support
  5333 for hiding of names;
  5334 
  5335 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5336 XSYMBOL_HOME; no longer need to do manual configuration in most
  5337 situations;
  5338 
  5339 * system: compression of ML heaps images may now be controlled via -c
  5340 option of isabelle and isatool usedir (currently only observed by
  5341 Poly/ML);
  5342 
  5343 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5344 useful for remote X11);
  5345 
  5346 * system: provide TAGS file for Isabelle sources;
  5347 
  5348 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5349 order;
  5350 
  5351 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5352 timing flag supersedes proof_timing and Toplevel.trace;
  5353 
  5354 * ML: new combinators |>> and |>>> for incremental transformations
  5355 with secondary results (e.g. certain theory extensions):
  5356 
  5357 * ML: PureThy.add_defs gets additional argument to indicate potential
  5358 overloading (usually false);
  5359 
  5360 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5361 results;
  5362 
  5363 
  5364 
  5365 New in Isabelle99 (October 1999)
  5366 --------------------------------
  5367 
  5368 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5369 
  5370 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5371 are no longer simplified.  (This allows the simplifier to unfold recursive
  5372 functional programs.)  To restore the old behaviour, declare
  5373 
  5374     Delcongs [if_weak_cong];
  5375 
  5376 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5377 complement;
  5378 
  5379 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5380 
  5381 * HOL/datatype: mutual_induct_tac no longer exists --
  5382   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5383 
  5384 * HOL/typedef: fixed type inference for representing set; type
  5385 arguments now have to occur explicitly on the rhs as type constraints;
  5386 
  5387 * ZF: The con_defs part of an inductive definition may no longer refer
  5388 to constants declared in the same theory;
  5389 
  5390 * HOL, ZF: the function mk_cases, generated by the inductive
  5391 definition package, has lost an argument.  To simplify its result, it
  5392 uses the default simpset instead of a supplied list of theorems.
  5393 
  5394 * HOL/List: the constructors of type list are now Nil and Cons;
  5395 
  5396 * Simplifier: the type of the infix ML functions
  5397         setSSolver addSSolver setSolver addSolver
  5398 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5399 for packaging solvers. A solver is created via
  5400         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5401 where the string argument is only a comment.
  5402 
  5403 
  5404 *** Proof tools ***
  5405 
  5406 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5407 decision procedure for linear arithmetic. Currently it is used for
  5408 types `nat', `int', and `real' in HOL (see below); it can, should and
  5409 will be instantiated for other types and logics as well.
  5410 
  5411 * The simplifier now accepts rewrite rules with flexible heads, eg
  5412      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5413   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5414   matching.
  5415 
  5416 
  5417 *** General ***
  5418 
  5419 * New Isabelle/Isar subsystem provides an alternative to traditional
  5420 tactical theorem proving; together with the ProofGeneral/isar user
  5421 interface it offers an interactive environment for developing human
  5422 readable proof documents (Isar == Intelligible semi-automated
  5423 reasoning); for further information see isatool doc isar-ref,
  5424 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5425 
  5426 * improved and simplified presentation of theories: better HTML markup
  5427 (including colors), graph views in several sizes; isatool usedir now
  5428 provides a proper interface for user theories (via -P option); actual
  5429 document preparation based on (PDF)LaTeX is available as well (for
  5430 new-style theories only); see isatool doc system for more information;
  5431 
  5432 * native support for Proof General, both for classic Isabelle and
  5433 Isabelle/Isar;
  5434 
  5435 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5436 using the graph browser tool;
  5437 
  5438 * Isabelle manuals now also available as PDF;
  5439 
  5440 * theory loader rewritten from scratch (may not be fully
  5441 bug-compatible); old loadpath variable has been replaced by show_path,
  5442 add_path, del_path, reset_path functions; new operations such as
  5443 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5444 isatool doc ref);
  5445 
  5446 * improved isatool install: option -k creates KDE application icon,
  5447 option -p DIR installs standalone binaries;
  5448 
  5449 * added ML_PLATFORM setting (useful for cross-platform installations);
  5450 more robust handling of platform specific ML images for SML/NJ;
  5451 
  5452 * the settings environment is now statically scoped, i.e. it is never
  5453 created again in sub-processes invoked from isabelle, isatool, or
  5454 Isabelle;
  5455 
  5456 * path element specification '~~' refers to '$ISABELLE_HOME';
  5457 
  5458 * in locales, the "assumes" and "defines" parts may be omitted if
  5459 empty;
  5460 
  5461 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5462 long arrows);
  5463 
  5464 * new print_mode "HTML";
  5465 
  5466 * new flag show_tags controls display of tags of theorems (which are
  5467 basically just comments that may be attached by some tools);
  5468 
  5469 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5470 mode and goal output format:
  5471 
  5472 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5473 244c244
  5474 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5475 ---
  5476 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5477 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5478 181c181
  5479 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5480 ---
  5481 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5482 
  5483 * function bind_thms stores lists of theorems (cf. bind_thm);
  5484 
  5485 * new shorthand tactics ftac, eatac, datac, fatac;
  5486 
  5487 * qed (and friends) now accept "" as result name; in that case the
  5488 theorem is not stored, but proper checks and presentation of the
  5489 result still apply;
  5490 
  5491 * theorem database now also indexes constants "Trueprop", "all",
  5492 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5493 
  5494 
  5495 *** HOL ***
  5496 
  5497 ** HOL arithmetic **
  5498 
  5499 * There are now decision procedures for linear arithmetic over nat and
  5500 int:
  5501 
  5502 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5503 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5504 are treated as atomic; subformulae not involving type `nat' or `int'
  5505 are ignored; quantified subformulae are ignored unless they are
  5506 positive universal or negative existential. The tactic has to be
  5507 invoked by hand and can be a little bit slow. In particular, the
  5508 running time is exponential in the number of occurrences of `min' and
  5509 `max', and `-' on `nat'.
  5510 
  5511 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5512 (negated) (in)equalities among the premises and the conclusion into
  5513 account (i.e. no compound formulae) and does not know about `min' and
  5514 `max', and `-' on `nat'. It is fast and is used automatically by the
  5515 simplifier.
  5516 
  5517 NB: At the moment, these decision procedures do not cope with mixed
  5518 nat/int formulae where the two parts interact, such as `m < n ==>
  5519 int(m) < int(n)'.
  5520 
  5521 * HOL/Numeral provides a generic theory of numerals (encoded
  5522 efficiently as bit strings); setup for types nat/int/real is in place;
  5523 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5524 int, existing theories and proof scripts may require a few additional
  5525 type constraints;
  5526 
  5527 * integer division and remainder can now be performed on constant
  5528 arguments;
  5529 
  5530 * many properties of integer multiplication, division and remainder
  5531 are now available;
  5532 
  5533 * An interface to the Stanford Validity Checker (SVC) is available through the
  5534 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5535 are proved automatically.  SVC must be installed separately, and its results
  5536 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5537 invocation of the underlying oracle).  For SVC see
  5538   http://verify.stanford.edu/SVC
  5539 
  5540 * IsaMakefile: the HOL-Real target now builds an actual image;
  5541 
  5542 
  5543 ** HOL misc **
  5544 
  5545 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5546 (in Isabelle/Isar) -- by Gertrud Bauer;
  5547 
  5548 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5549 analysis for assembly languages with subtypes;
  5550 
  5551 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5552 -- avoids syntactic ambiguities and treats state, transition, and
  5553 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5554 changed syntax and (many) tactics;
  5555 
  5556 * HOL/inductive: Now also handles more general introduction rules such
  5557   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5558   theorems are now maintained within the theory (maintained via the
  5559   "mono" attribute);
  5560 
  5561 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5562   (using function types) such as
  5563 
  5564   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5565 
  5566 * HOL/record: record_simproc (part of the default simpset) takes care
  5567 of selectors applied to updated records; record_split_tac is no longer
  5568 part of the default claset; update_defs may now be removed from the
  5569 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5570 
  5571   claset_ref () := claset() addSWrapper record_split_wrapper;
  5572   Delsimprocs [record_simproc]
  5573 
  5574 * HOL/typedef: fixed type inference for representing set; type
  5575 arguments now have to occur explicitly on the rhs as type constraints;
  5576 
  5577 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5578 names rather than an ML expression;
  5579 
  5580 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5581 supplied later.  Program schemes can be defined, such as
  5582     "While B C s = (if B s then While B C (C s) else s)"
  5583 where the well-founded relation can be chosen after B and C have been given.
  5584 
  5585 * HOL/List: the constructors of type list are now Nil and Cons;
  5586 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5587 course, ML tools referring to List.list.op # etc. have to be adapted;
  5588 
  5589 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5590 disabled by default; run isabelle with option -m HOL to get back to
  5591 the original Gordon/HOL-style output;
  5592 
  5593 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5594 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5595 
  5596 * HOL basic syntax simplified (more orthogonal): all variants of
  5597 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5598 Eps operator is provided as well: "SOME x. P[x]";
  5599 
  5600 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5601 
  5602 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5603 thus available for user theories;
  5604 
  5605 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5606 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5607 time;
  5608 
  5609 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5610 several times and then mp;
  5611 
  5612 
  5613 *** LK ***
  5614 
  5615 * the notation <<...>> is now available as a notation for sequences of
  5616 formulas;
  5617 
  5618 * the simplifier is now installed
  5619 
  5620 * the axiom system has been generalized (thanks to Soren Heilmann)
  5621 
  5622 * the classical reasoner now has a default rule database
  5623 
  5624 
  5625 *** ZF ***
  5626 
  5627 * new primrec section allows primitive recursive functions to be given
  5628 directly (as in HOL) over datatypes and the natural numbers;
  5629 
  5630 * new tactics induct_tac and exhaust_tac for induction (or case
  5631 analysis) over datatypes and the natural numbers;
  5632 
  5633 * the datatype declaration of type T now defines the recursor T_rec;
  5634 
  5635 * simplification automatically does freeness reasoning for datatype
  5636 constructors;
  5637 
  5638 * automatic type-inference, with AddTCs command to insert new
  5639 type-checking rules;
  5640 
  5641 * datatype introduction rules are now added as Safe Introduction rules
  5642 to the claset;
  5643 
  5644 * the syntax "if P then x else y" is now available in addition to
  5645 if(P,x,y);
  5646 
  5647 
  5648 *** Internal programming interfaces ***
  5649 
  5650 * tuned simplifier trace output; new flag debug_simp;
  5651 
  5652 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5653 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5654 
  5655 * AxClass.axclass_tac lost the theory argument;
  5656 
  5657 * tuned current_goals_markers semantics: begin / end goal avoids
  5658 printing empty lines;
  5659 
  5660 * removed prs and prs_fn hook, which was broken because it did not
  5661 include \n in its semantics, forcing writeln to add one
  5662 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5663 string -> unit if you really want to output text without newline;
  5664 
  5665 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5666 plain output, interface builders may have to enable 'isabelle_font'
  5667 mode to get Isabelle font glyphs as before;
  5668 
  5669 * refined token_translation interface; INCOMPATIBILITY: output length
  5670 now of type real instead of int;
  5671 
  5672 * theory loader actions may be traced via new ThyInfo.add_hook
  5673 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5674 your own database of information attached to *whole* theories -- as
  5675 opposed to intra-theory data slots offered via TheoryDataFun;
  5676 
  5677 * proper handling of dangling sort hypotheses (at last!);
  5678 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5679 extra sort hypotheses that can be witnessed from the type signature;
  5680 the force_strip_shyps flag is gone, any remaining shyps are simply
  5681 left in the theorem (with a warning issued by strip_shyps_warning);
  5682 
  5683 
  5684 
  5685 New in Isabelle98-1 (October 1998)
  5686 ----------------------------------
  5687 
  5688 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5689 
  5690 * several changes of automated proof tools;
  5691 
  5692 * HOL: major changes to the inductive and datatype packages, including
  5693 some minor incompatibilities of theory syntax;
  5694 
  5695 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5696 called `inj_on';
  5697 
  5698 * HOL: removed duplicate thms in Arith:
  5699   less_imp_add_less  should be replaced by  trans_less_add1
  5700   le_imp_add_le      should be replaced by  trans_le_add1
  5701 
  5702 * HOL: unary minus is now overloaded (new type constraints may be
  5703 required);
  5704 
  5705 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5706 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5707 now taken as an integer constant.
  5708 
  5709 * Pure: ML function 'theory_of' renamed to 'theory';
  5710 
  5711 
  5712 *** Proof tools ***
  5713 
  5714 * Simplifier:
  5715   1. Asm_full_simp_tac is now more aggressive.
  5716      1. It will sometimes reorient premises if that increases their power to
  5717         simplify.
  5718      2. It does no longer proceed strictly from left to right but may also
  5719         rotate premises to achieve further simplification.
  5720      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5721      old Asm_full_simp_tac in that it does not rotate premises.
  5722   2. The simplifier now knows a little bit about nat-arithmetic.
  5723 
  5724 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5725 allows for selected deletion of wrappers, by introduction of names for
  5726 wrapper functionals.  This implies that addbefore, addSbefore,
  5727 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5728 and that adding two tactics with the same name overwrites the first
  5729 one (emitting a warning).
  5730   type wrapper = (int -> tactic) -> (int -> tactic)
  5731   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5732   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5733   delWrapper, delSWrapper: claset *  string            -> claset
  5734   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5735 
  5736 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5737 semantics; addbefore now affects only the unsafe part of step_tac
  5738 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5739 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5740 by Force_tac;
  5741 
  5742 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5743 compWrapper; added safe wrapper (and access functions for it);
  5744 
  5745 * HOL/split_all_tac is now much faster and fails if there is nothing
  5746 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5747 and the names of the automatically generated variables have changed.
  5748 split_all_tac has moved within claset() from unsafe wrappers to safe
  5749 wrappers, which means that !!-bound variables are split much more
  5750 aggressively, and safe_tac and clarify_tac now split such variables.
  5751 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5752 Note: the same holds for record_split_tac, which does the job of
  5753 split_all_tac for record fields.
  5754 
  5755 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5756 permanently to the default simpset using Addsplits just like
  5757 Addsimps. They can be removed via Delsplits just like
  5758 Delsimps. Lower-case versions are also available.
  5759 
  5760 * HOL/Simplifier: The rule split_if is now part of the default
  5761 simpset. This means that the simplifier will eliminate all occurrences
  5762 of if-then-else in the conclusion of a goal. To prevent this, you can
  5763 either remove split_if completely from the default simpset by
  5764 `Delsplits [split_if]' or remove it in a specific call of the
  5765 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5766 other case splitting rules to/from the default simpset: every datatype
  5767 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5768 t is the name of the datatype).
  5769 
  5770 * Classical reasoner / Simplifier combination: new force_tac (and
  5771 derivatives Force_tac, force) combines rewriting and classical
  5772 reasoning (and whatever other tools) similarly to auto_tac, but is
  5773 aimed to solve the given subgoal completely.
  5774 
  5775 
  5776 *** General ***
  5777 
  5778 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5779 and `goalw': the theory is no longer needed as an explicit argument -
  5780 the current theory context is used; assumptions are no longer returned
  5781 at the ML-level unless one of them starts with ==> or !!; it is
  5782 recommended to convert to these new commands using isatool fixgoal
  5783 (backup your sources first!);
  5784 
  5785 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5786 the current theory context, and 'theory' to lookup stored theories;
  5787 
  5788 * new theory section 'locale' for declaring constants, assumptions and
  5789 definitions that have local scope;
  5790 
  5791 * new theory section 'nonterminals' for purely syntactic types;
  5792 
  5793 * new theory section 'setup' for generic ML setup functions
  5794 (e.g. package initialization);
  5795 
  5796 * the distribution now includes Isabelle icons: see
  5797 lib/logo/isabelle-{small,tiny}.xpm;
  5798 
  5799 * isatool install - install binaries with absolute references to
  5800 ISABELLE_HOME/bin;
  5801 
  5802 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5803 
  5804 * print mode 'emacs' reserved for Isamode;
  5805 
  5806 * support multiple print (ast) translations per constant name;
  5807 
  5808 * theorems involving oracles are now printed with a suffixed [!];
  5809 
  5810 
  5811 *** HOL ***
  5812 
  5813 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5814 
  5815 * HOL/inductive package reorganized and improved: now supports mutual
  5816 definitions such as
  5817 
  5818   inductive EVEN ODD
  5819     intrs
  5820       null "0 : EVEN"
  5821       oddI "n : EVEN ==> Suc n : ODD"
  5822       evenI "n : ODD ==> Suc n : EVEN"
  5823 
  5824 new theorem list "elims" contains an elimination rule for each of the
  5825 recursive sets; inductive definitions now handle disjunctive premises
  5826 correctly (also ZF);
  5827 
  5828 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5829 "mutual_induct" no longer exists - the induction rule is always
  5830 contained in "induct";
  5831 
  5832 
  5833 * HOL/datatype package re-implemented and greatly improved: now
  5834 supports mutually recursive datatypes such as
  5835 
  5836   datatype
  5837     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5838             | SUM ('a aexp) ('a aexp)
  5839             | DIFF ('a aexp) ('a aexp)
  5840             | NUM 'a
  5841   and
  5842     'a bexp = LESS ('a aexp) ('a aexp)
  5843             | AND ('a bexp) ('a bexp)
  5844             | OR ('a bexp) ('a bexp)
  5845 
  5846 as well as indirectly recursive datatypes such as
  5847 
  5848   datatype
  5849     ('a, 'b) term = Var 'a
  5850                   | App 'b ((('a, 'b) term) list)
  5851 
  5852 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5853 induction on mutually / indirectly recursive datatypes.
  5854 
  5855 Primrec equations are now stored in theory and can be accessed via
  5856 <function_name>.simps.
  5857 
  5858 INCOMPATIBILITIES:
  5859 
  5860   - Theories using datatypes must now have theory Datatype as an
  5861     ancestor.
  5862   - The specific <typename>.induct_tac no longer exists - use the
  5863     generic induct_tac instead.
  5864   - natE has been renamed to nat.exhaust - use exhaust_tac
  5865     instead of res_inst_tac ... natE. Note that the variable
  5866     names in nat.exhaust differ from the names in natE, this
  5867     may cause some "fragile" proofs to fail.
  5868   - The theorems split_<typename>_case and split_<typename>_case_asm
  5869     have been renamed to <typename>.split and <typename>.split_asm.
  5870   - Since default sorts of type variables are now handled correctly,
  5871     some datatype definitions may have to be annotated with explicit
  5872     sort constraints.
  5873   - Primrec definitions no longer require function name and type
  5874     of recursive argument.
  5875 
  5876 Consider using isatool fixdatatype to adapt your theories and proof
  5877 scripts to the new package (backup your sources first!).
  5878 
  5879 
  5880 * HOL/record package: considerably improved implementation; now
  5881 includes concrete syntax for record types, terms, updates; theorems
  5882 for surjective pairing and splitting !!-bound record variables; proof
  5883 support is as follows:
  5884 
  5885   1) standard conversions (selectors or updates applied to record
  5886 constructor terms) are part of the standard simpset;
  5887 
  5888   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5889 made part of standard simpset and claset via addIffs;
  5890 
  5891   3) a tactic for record field splitting (record_split_tac) is part of
  5892 the standard claset (addSWrapper);
  5893 
  5894 To get a better idea about these rules you may retrieve them via
  5895 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5896 the name of your record type.
  5897 
  5898 The split tactic 3) conceptually simplifies by the following rule:
  5899 
  5900   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5901 
  5902 Thus any record variable that is bound by meta-all will automatically
  5903 blow up into some record constructor term, consequently the
  5904 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5905 solve record problems automatically.
  5906 
  5907 
  5908 * reorganized the main HOL image: HOL/Integ and String loaded by
  5909 default; theory Main includes everything;
  5910 
  5911 * automatic simplification of integer sums and comparisons, using cancellation;
  5912 
  5913 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5914 
  5915 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5916 
  5917 * many new identities for unions, intersections, set difference, etc.;
  5918 
  5919 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  5920 called split_if, split_split, split_sum_case and split_nat_case (to go
  5921 with add/delsplits);
  5922 
  5923 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  5924 (?x::unit) = (); this is made part of the default simpset, which COULD
  5925 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  5926 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  5927 unit_abs_eta_conv is added in order to counter the effect of
  5928 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  5929 %u.f();
  5930 
  5931 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  5932 makes more sense);
  5933 
  5934 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5935   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5936   disjointness reasoning but breaking a few old proofs.
  5937 
  5938 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  5939 to 'converse' from 'inverse' (for compatibility with ZF and some
  5940 literature);
  5941 
  5942 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  5943 the well-founded relation;
  5944 
  5945 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  5946     Compl A.  The "Compl" syntax remains available as input syntax for this
  5947     release ONLY.
  5948 
  5949 * HOL/Update: new theory of function updates:
  5950     f(a:=b) == %x. if x=a then b else f x
  5951 may also be iterated as in f(a:=b,c:=d,...);
  5952 
  5953 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  5954 
  5955 * HOL/List:
  5956   - new function list_update written xs[i:=v] that updates the i-th
  5957     list position. May also be iterated as in xs[i:=a,j:=b,...].
  5958   - new function `upt' written [i..j(] which generates the list
  5959     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  5960     bound write [i..j], which is a shorthand for [i..j+1(].
  5961   - new lexicographic orderings and corresponding wellfoundedness theorems.
  5962 
  5963 * HOL/Arith:
  5964   - removed 'pred' (predecessor) function;
  5965   - generalized some theorems about n-1;
  5966   - many new laws about "div" and "mod";
  5967   - new laws about greatest common divisors (see theory ex/Primes);
  5968 
  5969 * HOL/Relation: renamed the relational operator r^-1 "converse"
  5970 instead of "inverse";
  5971 
  5972 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  5973   of the multiset ordering;
  5974 
  5975 * directory HOL/Real: a construction of the reals using Dedekind cuts
  5976   (not included by default);
  5977 
  5978 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  5979 
  5980 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  5981   programs, i.e. different program variables may have different types.
  5982 
  5983 * calling (stac rew i) now fails if "rew" has no effect on the goal
  5984   [previously, this check worked only if the rewrite rule was unconditional]
  5985   Now rew can involve either definitions or equalities (either == or =).
  5986 
  5987 
  5988 *** ZF ***
  5989 
  5990 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  5991   only the theorems proved on ZF.ML;
  5992 
  5993 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  5994   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  5995   disjointness reasoning but breaking a few old proofs.
  5996 
  5997 * ZF/Update: new theory of function updates
  5998     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  5999   may also be iterated as in f(a:=b,c:=d,...);
  6000 
  6001 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6002 
  6003 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6004   [previously, this check worked only if the rewrite rule was unconditional]
  6005   Now rew can involve either definitions or equalities (either == or =).
  6006 
  6007 * case_tac provided for compatibility with HOL
  6008     (like the old excluded_middle_tac, but with subgoals swapped)
  6009 
  6010 
  6011 *** Internal programming interfaces ***
  6012 
  6013 * Pure: several new basic modules made available for general use, see
  6014 also src/Pure/README;
  6015 
  6016 * improved the theory data mechanism to support encapsulation (data
  6017 kind name replaced by private Object.kind, acting as authorization
  6018 key); new type-safe user interface via functor TheoryDataFun; generic
  6019 print_data function becomes basically useless;
  6020 
  6021 * removed global_names compatibility flag -- all theory declarations
  6022 are qualified by default;
  6023 
  6024 * module Pure/Syntax now offers quote / antiquote translation
  6025 functions (useful for Hoare logic etc. with implicit dependencies);
  6026 see HOL/ex/Antiquote for an example use;
  6027 
  6028 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  6029 cterm -> thm;
  6030 
  6031 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  6032 subgoal;
  6033 
  6034 * Display.print_goals function moved to Locale.print_goals;
  6035 
  6036 * standard print function for goals supports current_goals_markers
  6037 variable for marking begin of proof, end of proof, start of goal; the
  6038 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  6039 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  6040 for example;
  6041 
  6042 
  6043 
  6044 New in Isabelle98 (January 1998)
  6045 --------------------------------
  6046 
  6047 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6048 
  6049 * changed lexical syntax of terms / types: dots made part of long
  6050 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6051 
  6052 * simpset (and claset) reference variable replaced by functions
  6053 simpset / simpset_ref;
  6054 
  6055 * no longer supports theory aliases (via merge) and non-trivial
  6056 implicit merge of thms' signatures;
  6057 
  6058 * most internal names of constants changed due to qualified names;
  6059 
  6060 * changed Pure/Sequence interface (see Pure/seq.ML);
  6061 
  6062 
  6063 *** General Changes ***
  6064 
  6065 * hierachically structured name spaces (for consts, types, axms, thms
  6066 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6067 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6068 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6069 long_names for fully qualified output names; NOTE: ML programs
  6070 (special tactics, packages etc.) referring to internal names may have
  6071 to be adapted to cope with fully qualified names; in case of severe
  6072 backward campatibility problems try setting 'global_names' at compile
  6073 time to have enrything declared within a flat name space; one may also
  6074 fine tune name declarations in theories via the 'global' and 'local'
  6075 section;
  6076 
  6077 * reimplemented the implicit simpset and claset using the new anytype
  6078 data filed in signatures; references simpset:simpset ref etc. are
  6079 replaced by functions simpset:unit->simpset and
  6080 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6081 to patch your ML files accordingly;
  6082 
  6083 * HTML output now includes theory graph data for display with Java
  6084 applet or isatool browser; data generated automatically via isatool
  6085 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6086 
  6087 * defs may now be conditional; improved rewrite_goals_tac to handle
  6088 conditional equations;
  6089 
  6090 * defs now admits additional type arguments, using TYPE('a) syntax;
  6091 
  6092 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6093 creates a new theory node; implicit merge of thms' signatures is
  6094 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6095 transfer:theory->thm->thm in (rare) cases;
  6096 
  6097 * improved handling of draft signatures / theories; draft thms (and
  6098 ctyps, cterms) are automatically promoted to real ones;
  6099 
  6100 * slightly changed interfaces for oracles: admit many per theory, named
  6101 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6102 
  6103 * print_goals: optional output of const types (set show_consts and
  6104 show_types);
  6105 
  6106 * improved output of warnings (###) and errors (***);
  6107 
  6108 * subgoal_tac displays a warning if the new subgoal has type variables;
  6109 
  6110 * removed old README and Makefiles;
  6111 
  6112 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6113 
  6114 * removed obsolete init_pps and init_database;
  6115 
  6116 * deleted the obsolete tactical STATE, which was declared by
  6117     fun STATE tacfun st = tacfun st st;
  6118 
  6119 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6120 (which abbreviates $HOME);
  6121 
  6122 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6123 use isatool fixseq to adapt your ML programs (this works for fully
  6124 qualified references to the Sequence structure only!);
  6125 
  6126 * use_thy no longer requires writable current directory; it always
  6127 reloads .ML *and* .thy file, if either one is out of date;
  6128 
  6129 
  6130 *** Classical Reasoner ***
  6131 
  6132 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6133 tactics that use classical reasoning to simplify a subgoal without
  6134 splitting it into several subgoals;
  6135 
  6136 * Safe_tac: like safe_tac but uses the default claset;
  6137 
  6138 
  6139 *** Simplifier ***
  6140 
  6141 * added simplification meta rules:
  6142     (asm_)(full_)simplify: simpset -> thm -> thm;
  6143 
  6144 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6145 logics (again);
  6146 
  6147 * added prems argument to simplification procedures;
  6148 
  6149 * HOL, FOL, ZF: added infix function `addsplits':
  6150   instead of `<simpset> setloop (split_tac <thms>)'
  6151   you can simply write `<simpset> addsplits <thms>'
  6152 
  6153 
  6154 *** Syntax ***
  6155 
  6156 * TYPE('a) syntax for type reflection terms;
  6157 
  6158 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6159 
  6160 * pretty printer: changed order of mixfix annotation preference (again!);
  6161 
  6162 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6163 
  6164 
  6165 *** HOL ***
  6166 
  6167 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  6168   with `addloop' of the simplifier to faciliate case splitting in premises.
  6169 
  6170 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  6171 
  6172 * HOL/Auth: new protocol proofs including some for the Internet
  6173   protocol TLS;
  6174 
  6175 * HOL/Map: new theory of `maps' a la VDM;
  6176 
  6177 * HOL/simplifier: simplification procedures nat_cancel_sums for
  6178 cancelling out common nat summands from =, <, <= (in)equalities, or
  6179 differences; simplification procedures nat_cancel_factor for
  6180 cancelling common factor from =, <, <= (in)equalities over natural
  6181 sums; nat_cancel contains both kinds of procedures, it is installed by
  6182 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  6183 
  6184 * HOL/simplifier: terms of the form
  6185   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  6186   are rewritten to
  6187   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  6188   and those of the form
  6189   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  6190   are rewritten to
  6191   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  6192 
  6193 * HOL/datatype
  6194   Each datatype `t' now comes with a theorem `split_t_case' of the form
  6195 
  6196   P(t_case f1 ... fn x) =
  6197      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  6198         ...
  6199        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  6200      )
  6201 
  6202   and a theorem `split_t_case_asm' of the form
  6203 
  6204   P(t_case f1 ... fn x) =
  6205     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  6206         ...
  6207        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  6208      )
  6209   which can be added to a simpset via `addsplits'. The existing theorems
  6210   expand_list_case and expand_option_case have been renamed to
  6211   split_list_case and split_option_case.
  6212 
  6213 * HOL/Arithmetic:
  6214   - `pred n' is automatically converted to `n-1'.
  6215     Users are strongly encouraged not to use `pred' any longer,
  6216     because it will disappear altogether at some point.
  6217   - Users are strongly encouraged to write "0 < n" rather than
  6218     "n ~= 0". Theorems and proof tools have been modified towards this
  6219     `standard'.
  6220 
  6221 * HOL/Lists:
  6222   the function "set_of_list" has been renamed "set" (and its theorems too);
  6223   the function "nth" now takes its arguments in the reverse order and
  6224   has acquired the infix notation "!" as in "xs!n".
  6225 
  6226 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  6227 
  6228 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  6229   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  6230 
  6231 * HOL/record: extensible records with schematic structural subtyping
  6232 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  6233 still lacks various theorems and concrete record syntax;
  6234 
  6235 
  6236 *** HOLCF ***
  6237 
  6238 * removed "axioms" and "generated by" sections;
  6239 
  6240 * replaced "ops" section by extended "consts" section, which is capable of
  6241   handling the continuous function space "->" directly;
  6242 
  6243 * domain package:
  6244   . proves theorems immediately and stores them in the theory,
  6245   . creates hierachical name space,
  6246   . now uses normal mixfix annotations (instead of cinfix...),
  6247   . minor changes to some names and values (for consistency),
  6248   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  6249