NEWS
author blanchet
Mon Nov 23 18:29:00 2009 +0100 (2009-11-23)
changeset 33877 e779bea3d337
parent 33860 dcd9affbd106
child 33873 e9120a7b2779
permissions -rw-r--r--
fix Nitpick soundness bug related to "finite (UNIV::'a set)" where "'a" is constrained by a sort to be infinite
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2009-1 (December 2009)
     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 * Locale interpretation propagates mixins along the locale hierarchy.
    16 The currently only available mixins are the equations used to map
    17 local definitions to terms of the target domain of an interpretation.
    18 
    19 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
    20 loc" to print all interpretations of locale "loc" in the theory.
    21 Interpretations in proofs are not shown.
    22 
    23 * Thoroughly revised locales tutorial.  New section on conditional
    24 interpretation.
    25 
    26 * On instantiation of classes, remaining undefined class parameters
    27 are formally declared.  INCOMPATIBILITY.
    28 
    29 
    30 *** Document preparation ***
    31 
    32 * New generalized style concept for printing terms: @{foo (style) ...}
    33 instead of @{foo_style style ...}  (old form is still retained for
    34 backward compatibility).  Styles can be also applied for
    35 antiquotations prop, term_type and typeof.
    36 
    37 
    38 *** HOL ***
    39 
    40 * New proof method "smt" for a combination of first-order logic with
    41 equality, linear and nonlinear (natural/integer/real) arithmetic, and
    42 fixed-size bitvectors; there is also basic support for higher-order
    43 features (esp. lambda abstractions).  It is an incomplete decision
    44 procedure based on external SMT solvers using the oracle mechanism;
    45 for the SMT solver Z3, this method is proof-producing.  Certificates
    46 are provided to avoid calling the external solvers solely for
    47 re-checking proofs.  Due to a remote SMT service there is no need for
    48 installing SMT solvers locally.  See src/HOL/SMT.
    49 
    50 * New commands to load and prove verification conditions generated by
    51 the Boogie program verifier or derived systems (e.g. the Verifying C
    52 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
    53 
    54 * New counterexample generator tool 'nitpick' based on the Kodkod
    55 relational model finder.  See src/HOL/Tools/Nitpick and
    56 src/HOL/Nitpick_Examples.
    57 
    58 * New commands 'code_pred' and 'values' to invoke the predicate
    59 compiler and to enumerate values of inductive predicates.
    60 
    61 * A tabled implementation of the reflexive transitive closure.
    62 
    63 * New implementation of quickcheck uses generic code generator;
    64 default generators are provided for all suitable HOL types, records
    65 and datatypes.  Old quickcheck can be re-activated importing theory
    66 Library/SML_Quickcheck.
    67 
    68 * New testing tool Mirabelle for automated proof tools.  Applies
    69 several tools and tactics like sledgehammer, metis, or quickcheck, to
    70 every proof step in a theory.  To be used in batch mode via the
    71 "mirabelle" utility.
    72 
    73 * New proof method "sos" (sum of squares) for nonlinear real
    74 arithmetic (originally due to John Harison). It requires theory
    75 Library/Sum_Of_Squares.  It is not a complete decision procedure but
    76 works well in practice on quantifier-free real arithmetic with +, -,
    77 *, ^, =, <= and <, i.e. boolean combinations of equalities and
    78 inequalities between polynomials.  It makes use of external
    79 semidefinite programming solvers.  Method "sos" generates a
    80 certificate that can be pasted into the proof thus avoiding the need
    81 to call an external tool every time the proof is checked.  See
    82 src/HOL/Library/Sum_Of_Squares.
    83 
    84 * New method "linarith" invokes existing linear arithmetic decision
    85 procedure only.
    86 
    87 * New command 'atp_minimal' reduces result produced by Sledgehammer.
    88 
    89 * New Sledgehammer option "Full Types" in Proof General settings menu.
    90 Causes full type information to be output to the ATPs.  This slows
    91 ATPs down considerably but eliminates a source of unsound "proofs"
    92 that fail later.
    93 
    94 * New method "metisFT": A version of metis that uses full type
    95 information in order to avoid failures of proof reconstruction.
    96 
    97 * New evaluator "approximate" approximates an real valued term using
    98 the same method as the approximation method.
    99 
   100 * Method "approximate" now supports arithmetic expressions as
   101 boundaries of intervals and implements interval splitting and Taylor
   102 series expansion.
   103 
   104 * ML antiquotation @{code_datatype} inserts definition of a datatype
   105 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   106 
   107 * New theory SupInf of the supremum and infimum operators for sets of
   108 reals.
   109 
   110 * New theory Probability, which contains a development of measure
   111 theory, eventually leading to Lebesgue integration and probability.
   112 
   113 * Extended Multivariate Analysis to include derivation and Brouwer's
   114 fixpoint theorem.
   115 
   116 * Reorganization of number theory, INCOMPATIBILITY:
   117   - new number theory development for nat and int, in
   118     theories Divides and GCD as well as in new session
   119     Number_Theory
   120   - some constants and facts now suffixed with _nat and
   121     _int accordingly
   122   - former session NumberTheory now named Old_Number_Theory,
   123     including theories Legacy_GCD and Primes (prefer Number_Theory
   124     if possible)
   125   - moved theory Pocklington from src/HOL/Library to
   126     src/HOL/Old_Number_Theory
   127 
   128 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and lcm
   129 of finite and infinite sets. It is shown that they form a complete
   130 lattice.
   131 
   132 * Class semiring_div requires superclass no_zero_divisors and proof of
   133 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   134 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   135 generalized to class semiring_div, subsuming former theorems
   136 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   137 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   138 INCOMPATIBILITY.
   139 
   140 * Refinements to lattice classes and sets:
   141   - less default intro/elim rules in locale variant, more default
   142     intro/elim rules in class variant: more uniformity
   143   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   144     le_inf_iff
   145   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   146     sup_aci)
   147   - renamed ACI to inf_sup_aci
   148   - new class "boolean_algebra"
   149   - class "complete_lattice" moved to separate theory
   150     "Complete_Lattice"; corresponding constants (and abbreviations)
   151     renamed and with authentic syntax:
   152     Set.Inf ~>    Complete_Lattice.Inf
   153     Set.Sup ~>    Complete_Lattice.Sup
   154     Set.INFI ~>   Complete_Lattice.INFI
   155     Set.SUPR ~>   Complete_Lattice.SUPR
   156     Set.Inter ~>  Complete_Lattice.Inter
   157     Set.Union ~>  Complete_Lattice.Union
   158     Set.INTER ~>  Complete_Lattice.INTER
   159     Set.UNION ~>  Complete_Lattice.UNION
   160   - authentic syntax for
   161     Set.Pow
   162     Set.image
   163   - mere abbreviations:
   164     Set.empty               (for bot)
   165     Set.UNIV                (for top)
   166     Set.inter               (for inf, formerly Set.Int)
   167     Set.union               (for sup, formerly Set.Un)
   168     Complete_Lattice.Inter  (for Inf)
   169     Complete_Lattice.Union  (for Sup)
   170     Complete_Lattice.INTER  (for INFI)
   171     Complete_Lattice.UNION  (for SUPR)
   172   - object-logic definitions as far as appropriate
   173 
   174 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   175 Un_subset_iff are explicitly deleted as default simp rules; then also
   176 their lattice counterparts le_inf_iff and le_sup_iff have to be
   177 deleted to achieve the desired effect.
   178 
   179 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   180 rules by default any longer; the same applies to min_max.inf_absorb1
   181 etc.  INCOMPATIBILITY.
   182 
   183 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   184 pred_set_conv by default.  INCOMPATIBILITY.
   185 
   186 * Power operations on relations and functions are now one dedicated
   187 constant "compow" with infix syntax "^^".  Power operation on
   188 multiplicative monoids retains syntax "^" and is now defined generic
   189 in class power.  INCOMPATIBILITY.
   190 
   191 * Relation composition "R O S" now has a more standard argument order:
   192 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   193 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   194 break, since the O_assoc rule was not rewritten like this.  Fix using
   195 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   196 
   197 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   198 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   199 INCOMPATIBILITY.
   200 
   201 --
   202 
   203 * Most rules produced by inductive and datatype package have mandatory
   204 prefixes.  INCOMPATIBILITY.
   205 
   206 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   207 the attribute of the same name.  Each of the theorems in the list
   208 DERIV_intros assumes composition with an additional function and
   209 matches a variable to the derivative, which has to be solved by the
   210 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   211 of most elementary terms.  Former Maclauren.DERIV_tac and Maclauren.deriv_tac
   212 should be replaced by (auto intro!: DERIV_intros).  INCOMPATIBILITY.
   213 
   214 * Code generator attributes follow the usual underscore convention:
   215     code_unfold     replaces    code unfold
   216     code_post       replaces    code post
   217     etc.
   218   INCOMPATIBILITY.
   219 
   220 * Renamed methods:
   221     sizechange -> size_change
   222     induct_scheme -> induction_schema
   223   INCOMPATIBILITY.
   224 
   225 * Discontinued abbreviation "arbitrary" of constant "undefined".
   226 INCOMPATIBILITY, use "undefined" directly.
   227 
   228 * Renamed theorems:
   229     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   230     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   231     Suc_plus1 -> Suc_eq_plus1
   232     *anti_sym -> *antisym*
   233     vector_less_eq_def -> vector_le_def
   234   INCOMPATIBILITY.
   235 
   236 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   237 INCOMPATIBILITY.
   238 
   239 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   240 INCOMPATIBILITY.
   241 
   242 
   243 *** HOLCF ***
   244 
   245 * Theory Representable defines a class "rep" of domains that are
   246 representable (via an ep-pair) in the universal domain type "udom".
   247 Instances are provided for all type constructors defined in HOLCF.
   248 
   249 * The 'new_domain' command is a purely definitional version of the
   250 domain package, for representable domains.  Syntax is identical to the
   251 old domain package.  The 'new_domain' package also supports indirect
   252 recursion using previously-defined type constructors.  See
   253 src/HOLCF/ex/New_Domain.thy for examples.
   254 
   255 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   256 on the left-hand side of an equation, and then performs
   257 simplification.  Rewriting is done using rules declared with the
   258 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   259 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   260 
   261 * The pattern-match compiler in 'fixrec' can now handle constructors
   262 with HOL function types.  Pattern-match combinators for the Pair
   263 constructor are pre-configured.
   264 
   265 * The 'fixrec' package now produces better fixed-point induction rules
   266 for mutually-recursive definitions:  Induction rules have conclusions
   267 of the form "P foo bar" instead of "P <foo, bar>".
   268 
   269 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   270 been renamed to "below".  The name "below" now replaces "less" in many
   271 theorem names.  (Legacy theorem names using "less" are still supported
   272 as well.)
   273 
   274 * The 'fixrec' package now supports "bottom patterns".  Bottom
   275 patterns can be used to generate strictness rules, or to make
   276 functions more strict (much like the bang-patterns supported by the
   277 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for examples.
   278 
   279 
   280 *** ML ***
   281 
   282 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   283 errors and run-time exceptions, including detailed source positions.
   284 
   285 * Structure Name_Space (formerly NameSpace) now manages uniquely
   286 identified entries, with some additional information such as source
   287 position, logical grouping etc.
   288 
   289 * Theory and context data is now introduced by the simplified and
   290 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   291 to be pure, but the old TheoryDataFun for mutable data (with explicit
   292 copy operation) is still available for some time.
   293 
   294 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   295 provides a high-level programming interface to synchronized state
   296 variables with atomic update.  This works via pure function
   297 application within a critical section -- its runtime should be as
   298 short as possible; beware of deadlocks if critical code is nested,
   299 either directly or indirectly via other synchronized variables!
   300 
   301 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   302 wraps raw ML references, explicitly indicating their non-thread-safe
   303 behaviour.  The Isar toplevel keeps this structure open, to
   304 accommodate Proof General as well as quick and dirty interactive
   305 experiments with references.
   306 
   307 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   308 parallel tactical reasoning.
   309 
   310 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   311 are similar to SUBPROOF, but are slightly more flexible: only the
   312 specified parts of the subgoal are imported into the context, and the
   313 body tactic may introduce new subgoals and schematic variables.
   314 
   315 * Old tactical METAHYPS, which does not observe the proof context, has
   316 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   317 or Subgoal.FOCUS etc.
   318 
   319 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   320 functors have their own ML name space there is no point to mark them
   321 separately.)  Minor INCOMPATIBILITY.
   322 
   323 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   324 
   325 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   326 INCOMPATIBILITY.
   327 
   328 * Operations of structure Skip_Proof no longer require quick_and_dirty
   329 mode, which avoids critical setmp.
   330 
   331 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   332 combinators for "args".  INCOMPATIBILITY, need to use simplified
   333 Attrib/Method.setup introduced in Isabelle2009.
   334 
   335 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   336 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   337 last resort.  INCOMPATIBILITY.
   338 
   339 * Display.pretty_thm now requires a proper context (cf. former
   340 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   341 or even Display.pretty_thm_without_context as last resort.
   342 INCOMPATIBILITY.
   343 
   344 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   345 Syntax.pretty_typ/term directly, preferably with proper context
   346 instead of global theory.
   347 
   348 
   349 *** System ***
   350 
   351 * Further fine tuning of parallel proof checking, scales up to 8 cores
   352 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   353 usedir option -q.
   354 
   355 * Support for additional "Isabelle components" via etc/components, see
   356 also the system manual.
   357 
   358 * The isabelle makeall tool now operates on all components with
   359 IsaMakefile, not just hardwired "logics".
   360 
   361 * Removed "compress" option from isabelle-process and isabelle usedir;
   362 this is always enabled.
   363 
   364 * Discontinued support for Poly/ML 4.x versions.
   365 
   366 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   367 on a given logic image.  This requires the lighttpd webserver and is
   368 currently supported on Linux only.
   369 
   370 
   371 
   372 New in Isabelle2009 (April 2009)
   373 --------------------------------
   374 
   375 *** General ***
   376 
   377 * Simplified main Isabelle executables, with less surprises on
   378 case-insensitive file-systems (such as Mac OS).
   379 
   380   - The main Isabelle tool wrapper is now called "isabelle" instead of
   381     "isatool."
   382 
   383   - The former "isabelle" alias for "isabelle-process" has been
   384     removed (should rarely occur to regular users).
   385 
   386   - The former "isabelle-interface" and its alias "Isabelle" have been
   387     removed (interfaces are now regular Isabelle tools).
   388 
   389 Within scripts and make files, the Isabelle environment variables
   390 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   391 respectively.  (The latter are still available as legacy feature.)
   392 
   393 The old isabelle-interface wrapper could react in confusing ways if
   394 the interface was uninstalled or changed otherwise.  Individual
   395 interface tool configuration is now more explicit, see also the
   396 Isabelle system manual.  In particular, Proof General is now available
   397 via "isabelle emacs".
   398 
   399 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   400 purge installed copies of Isabelle executables and re-run "isabelle
   401 install -p ...", or use symlinks.
   402 
   403 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   404 old ~/isabelle, which was slightly non-standard and apt to cause
   405 surprises on case-insensitive file-systems (such as Mac OS).
   406 
   407 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   408 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   409 care is required when using older releases of Isabelle.  Note that
   410 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   411 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   412 
   413 * Proofs of fully specified statements are run in parallel on
   414 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   415 a regular 4-core machine, if the initial heap space is made reasonably
   416 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   417 
   418 * The main reference manuals ("isar-ref", "implementation", and
   419 "system") have been updated and extended.  Formally checked references
   420 as hyperlinks are now available uniformly.
   421 
   422 
   423 *** Pure ***
   424 
   425 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   426 respects.  The most important changes are listed below.  See the
   427 Tutorial on Locales ("locales" manual) for details.
   428 
   429 - In locale expressions, instantiation replaces renaming.  Parameters
   430 must be declared in a for clause.  To aid compatibility with previous
   431 parameter inheritance, in locale declarations, parameters that are not
   432 'touched' (instantiation position "_" or omitted) are implicitly added
   433 with their syntax at the beginning of the for clause.
   434 
   435 - Syntax from abbreviations and definitions in locales is available in
   436 locale expressions and context elements.  The latter is particularly
   437 useful in locale declarations.
   438 
   439 - More flexible mechanisms to qualify names generated by locale
   440 expressions.  Qualifiers (prefixes) may be specified in locale
   441 expressions, and can be marked as mandatory (syntax: "name!:") or
   442 optional (syntax "name?:").  The default depends for plain "name:"
   443 depends on the situation where a locale expression is used: in
   444 commands 'locale' and 'sublocale' prefixes are optional, in
   445 'interpretation' and 'interpret' prefixes are mandatory.  The old
   446 implicit qualifiers derived from the parameter names of a locale are
   447 no longer generated.
   448 
   449 - Command "sublocale l < e" replaces "interpretation l < e".  The
   450 instantiation clause in "interpretation" and "interpret" (square
   451 brackets) is no longer available.  Use locale expressions.
   452 
   453 - When converting proof scripts, mandatory qualifiers in
   454 'interpretation' and 'interpret' should be retained by default, even
   455 if this is an INCOMPATIBILITY compared to former behavior.  In the
   456 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   457 in locale expressions range over a single locale instance only.
   458 
   459 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   460 In existing theorem specifications replace the includes element by the
   461 respective context elements of the included locale, omitting those
   462 that are already present in the theorem specification.  Multiple
   463 assume elements of a locale should be replaced by a single one
   464 involving the locale predicate.  In the proof body, declarations (most
   465 notably theorems) may be regained by interpreting the respective
   466 locales in the proof context as required (command "interpret").
   467 
   468 If using "includes" in replacement of a target solely because the
   469 parameter types in the theorem are not as general as in the target,
   470 consider declaring a new locale with additional type constraints on
   471 the parameters (context element "constrains").
   472 
   473 - Discontinued "locale (open)".  INCOMPATIBILITY.
   474 
   475 - Locale interpretation commands no longer attempt to simplify goal.
   476 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   477 methods intro_locales and unfold_locales to clarify.
   478 
   479 - Locale interpretation commands no longer accept interpretation
   480 attributes.  INCOMPATIBILITY.
   481 
   482 * Class declaration: so-called "base sort" must not be given in import
   483 list any longer, but is inferred from the specification.  Particularly
   484 in HOL, write
   485 
   486     class foo = ...
   487 
   488 instead of
   489 
   490     class foo = type + ...
   491 
   492 * Class target: global versions of theorems stemming do not carry a
   493 parameter prefix any longer.  INCOMPATIBILITY.
   494 
   495 * Class 'instance' command no longer accepts attached definitions.
   496 INCOMPATIBILITY, use proper 'instantiation' target instead.
   497 
   498 * Recovered hiding of consts, which was accidentally broken in
   499 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   500 makes c inaccessible; consider using ``hide (open) const c'' instead.
   501 
   502 * Slightly more coherent Pure syntax, with updated documentation in
   503 isar-ref manual.  Removed locales meta_term_syntax and
   504 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   505 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   506 directly in regular applications.
   507 
   508 * There is a new syntactic category "float_const" for signed decimal
   509 fractions (e.g. 123.45 or -123.45).
   510 
   511 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   512 interface with 'setup' command instead.
   513 
   514 * Command 'local_setup' is similar to 'setup', but operates on a local
   515 theory context.
   516 
   517 * The 'axiomatization' command now only works within a global theory
   518 context.  INCOMPATIBILITY.
   519 
   520 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   521 hypotheses.  Sorts required in the course of reasoning need to be
   522 covered by the constraints in the initial statement, completed by the
   523 type instance information of the background theory.  Non-trivial sort
   524 hypotheses, which rarely occur in practice, may be specified via
   525 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   526 
   527   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   528 
   529 The result contains an implicit sort hypotheses as before --
   530 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   531 normalization.
   532 
   533 * Generalized Isar history, with support for linear undo, direct state
   534 addressing etc.
   535 
   536 * Changed defaults for unify configuration options:
   537 
   538   unify_trace_bound = 50 (formerly 25)
   539   unify_search_bound = 60 (formerly 30)
   540 
   541 * Different bookkeeping for code equations (INCOMPATIBILITY):
   542 
   543   a) On theory merge, the last set of code equations for a particular
   544      constant is taken (in accordance with the policy applied by other
   545      parts of the code generator framework).
   546 
   547   b) Code equations stemming from explicit declarations (e.g. code
   548      attribute) gain priority over default code equations stemming
   549      from definition, primrec, fun etc.
   550 
   551 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   552 
   553 * Unified theorem tables for both code generators.  Thus [code
   554 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   555 
   556 * Command 'find_consts' searches for constants based on type and name
   557 patterns, e.g.
   558 
   559     find_consts "_ => bool"
   560 
   561 By default, matching is against subtypes, but it may be restricted to
   562 the whole type.  Searching by name is possible.  Multiple queries are
   563 conjunctive and queries may be negated by prefixing them with a
   564 hyphen:
   565 
   566     find_consts strict: "_ => bool" name: "Int" -"int => int"
   567 
   568 * New 'find_theorems' criterion "solves" matches theorems that
   569 directly solve the current goal (modulo higher-order unification).
   570 
   571 * Auto solve feature for main theorem statements: whenever a new goal
   572 is stated, "find_theorems solves" is called; any theorems that could
   573 solve the lemma directly are listed as part of the goal state.
   574 Cf. associated options in Proof General Isabelle settings menu,
   575 enabled by default, with reasonable timeout for pathological cases of
   576 higher-order unification.
   577 
   578 
   579 *** Document preparation ***
   580 
   581 * Antiquotation @{lemma} now imitates a regular terminal proof,
   582 demanding keyword 'by' and supporting the full method expression
   583 syntax just like the Isar command 'by'.
   584 
   585 
   586 *** HOL ***
   587 
   588 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   589 points Main and Complex_Main remain as before.
   590 
   591 * Logic image HOL-Plain provides a minimal HOL with the most important
   592 tools available (inductive, datatype, primrec, ...).  This facilitates
   593 experimentation and tool development.  Note that user applications
   594 (and library theories) should never refer to anything below theory
   595 Main, as before.
   596 
   597 * Logic image HOL-Main stops at theory Main, and thus facilitates
   598 experimentation due to shorter build times.
   599 
   600 * Logic image HOL-NSA contains theories of nonstandard analysis which
   601 were previously part of former HOL-Complex.  Entry point Hyperreal
   602 remains valid, but theories formerly using Complex_Main should now use
   603 new entry point Hypercomplex.
   604 
   605 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   606 Posix processes.  Avoids potentially expensive forking of the ML
   607 process.  New thread-based implementation also works on non-Unix
   608 platforms (Cygwin).  Provers are no longer hardwired, but defined
   609 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   610 commands are covered in the isar-ref manual.
   611 
   612 * Wrapper scripts for remote SystemOnTPTP service allows to use
   613 sledgehammer without local ATP installation (Vampire etc.). Other
   614 provers may be included via suitable ML wrappers, see also
   615 src/HOL/ATP_Linkup.thy.
   616 
   617 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   618 menu.
   619 
   620 * The metis method no longer fails because the theorem is too trivial
   621 (contains the empty clause).
   622 
   623 * The metis method now fails in the usual manner, rather than raising
   624 an exception, if it determines that it cannot prove the theorem.
   625 
   626 * Method "coherent" implements a prover for coherent logic (see also
   627 src/Tools/coherent.ML).
   628 
   629 * Constants "undefined" and "default" replace "arbitrary".  Usually
   630 "undefined" is the right choice to replace "arbitrary", though
   631 logically there is no difference.  INCOMPATIBILITY.
   632 
   633 * Command "value" now integrates different evaluation mechanisms.  The
   634 result of the first successful evaluation mechanism is printed.  In
   635 square brackets a particular named evaluation mechanisms may be
   636 specified (currently, [SML], [code] or [nbe]).  See further
   637 src/HOL/ex/Eval_Examples.thy.
   638 
   639 * Normalization by evaluation now allows non-leftlinear equations.
   640 Declare with attribute [code nbe].
   641 
   642 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   643 as the structured Isar versions "cases" and "induct", cf. the
   644 corresponding "cases" and "induct" attributes.  Mutual induction rules
   645 are now presented as a list of individual projections
   646 (e.g. foo_bar.inducts for types foo and bar); the old format with
   647 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   648 rare situations a different rule is selected --- notably nested tuple
   649 elimination instead of former prod.exhaust: use explicit (case_tac t
   650 rule: prod.exhaust) here.
   651 
   652 * Attributes "cases", "induct", "coinduct" support "del" option.
   653 
   654 * Removed fact "case_split_thm", which duplicates "case_split".
   655 
   656 * The option datatype has been moved to a new theory Option.  Renamed
   657 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   658 
   659 * New predicate "strict_mono" classifies strict functions on partial
   660 orders.  With strict functions on linear orders, reasoning about
   661 (in)equalities is facilitated by theorems "strict_mono_eq",
   662 "strict_mono_less_eq" and "strict_mono_less".
   663 
   664 * Some set operations are now proper qualified constants with
   665 authentic syntax.  INCOMPATIBILITY:
   666 
   667     op Int ~>   Set.Int
   668     op Un ~>    Set.Un
   669     INTER ~>    Set.INTER
   670     UNION ~>    Set.UNION
   671     Inter ~>    Set.Inter
   672     Union ~>    Set.Union
   673     {} ~>       Set.empty
   674     UNIV ~>     Set.UNIV
   675 
   676 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   677 theory Set.
   678 
   679 * Auxiliary class "itself" has disappeared -- classes without any
   680 parameter are treated as expected by the 'class' command.
   681 
   682 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   683 
   684 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   685 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   686 
   687 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   688 method "approximation".  It proves formulas on real values by using
   689 interval arithmetic.  In the formulas are also the transcendental
   690 functions sin, cos, tan, atan, ln, exp and the constant pi are
   691 allowed. For examples see
   692 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   693 
   694 * Theory "Reflection" now resides in HOL/Library.
   695 
   696 * Entry point to Word library now simply named "Word".
   697 INCOMPATIBILITY.
   698 
   699 * Made source layout more coherent with logical distribution
   700 structure:
   701 
   702     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   703     src/HOL/Library/Code_Message.thy ~> src/HOL/
   704     src/HOL/Library/GCD.thy ~> src/HOL/
   705     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   706     src/HOL/Library/Parity.thy ~> src/HOL/
   707     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   708     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   709     src/HOL/Real/Lubs.thy ~> src/HOL/
   710     src/HOL/Real/PReal.thy ~> src/HOL/
   711     src/HOL/Real/Rational.thy ~> src/HOL/
   712     src/HOL/Real/RComplete.thy ~> src/HOL/
   713     src/HOL/Real/RealDef.thy ~> src/HOL/
   714     src/HOL/Real/RealPow.thy ~> src/HOL/
   715     src/HOL/Real/Real.thy ~> src/HOL/
   716     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   717     src/HOL/Complex/Complex.thy ~> src/HOL/
   718     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   719     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   720     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   721     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   722     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   723     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   724     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   725     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   726     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   727     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   728     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   729     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   730     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   731     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   732     src/HOL/Real/Float ~> src/HOL/Library/
   733     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   734     src/HOL/Real/RealVector.thy ~> src/HOL/
   735 
   736     src/HOL/arith_data.ML ~> src/HOL/Tools
   737     src/HOL/hologic.ML ~> src/HOL/Tools
   738     src/HOL/simpdata.ML ~> src/HOL/Tools
   739     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   740     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   741     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   742     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   743     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   744     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   745     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   746 
   747     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   748     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   749     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   750     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   751     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   752     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   753 
   754 * If methods "eval" and "evaluation" encounter a structured proof
   755 state with !!/==>, only the conclusion is evaluated to True (if
   756 possible), avoiding strange error messages.
   757 
   758 * Method "sizechange" automates termination proofs using (a
   759 modification of) the size-change principle.  Requires SAT solver.  See
   760 src/HOL/ex/Termination.thy for examples.
   761 
   762 * Simplifier: simproc for let expressions now unfolds if bound
   763 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   764 
   765 * Method "arith": Linear arithmetic now ignores all inequalities when
   766 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   767 
   768 * New attribute "arith" for facts that should always be used
   769 automatically by arithmetic. It is intended to be used locally in
   770 proofs, e.g.
   771 
   772   assumes [arith]: "x > 0"
   773 
   774 Global usage is discouraged because of possible performance impact.
   775 
   776 * New classes "top" and "bot" with corresponding operations "top" and
   777 "bot" in theory Orderings; instantiation of class "complete_lattice"
   778 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   779 
   780 * Changed definition lemma "less_fun_def" in order to provide an
   781 instance for preorders on functions; use lemma "less_le" instead.
   782 INCOMPATIBILITY.
   783 
   784 * Theory Orderings: class "wellorder" moved here, with explicit
   785 induction rule "less_induct" as assumption.  For instantiation of
   786 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   787 INCOMPATIBILITY.
   788 
   789 * Theory Orderings: added class "preorder" as superclass of "order".
   790 INCOMPATIBILITY: Instantiation proofs for order, linorder
   791 etc. slightly changed.  Some theorems named order_class.* now named
   792 preorder_class.*.
   793 
   794 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   795 "diag" to "Id_on".
   796 
   797 * Theory Finite_Set: added a new fold combinator of type
   798 
   799   ('a => 'b => 'b) => 'b => 'a set => 'b
   800 
   801 Occasionally this is more convenient than the old fold combinator
   802 which is now defined in terms of the new one and renamed to
   803 fold_image.
   804 
   805 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   806 and "ring_simps" have been replaced by "algebra_simps" (which can be
   807 extended with further lemmas!).  At the moment both still exist but
   808 the former will disappear at some point.
   809 
   810 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   811 class recpower.  Type-specific simp rules for various recpower types
   812 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   813 
   814 rat_power_0    -> power_0
   815 rat_power_Suc  -> power_Suc
   816 realpow_0      -> power_0
   817 realpow_Suc    -> power_Suc
   818 complexpow_0   -> power_0
   819 complexpow_Suc -> power_Suc
   820 power_poly_0   -> power_0
   821 power_poly_Suc -> power_Suc
   822 
   823 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   824 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   825 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   826 of lemmas from Divides has been generalized from nat to class
   827 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   828 renames resulting from duplicate elimination:
   829 
   830     dvd_def_mod ~>          dvd_eq_mod_eq_0
   831     zero_dvd_iff ~>         dvd_0_left_iff
   832     dvd_0 ~>                dvd_0_right
   833     DIVISION_BY_ZERO_DIV ~> div_by_0
   834     DIVISION_BY_ZERO_MOD ~> mod_by_0
   835     mult_div ~>             div_mult_self2_is_id
   836     mult_mod ~>             mod_mult_self2_is_0
   837 
   838 * Theory IntDiv: removed many lemmas that are instances of class-based
   839 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   840 rename old lemmas as follows:
   841 
   842 dvd_diff               -> nat_dvd_diff
   843 dvd_zminus_iff         -> dvd_minus_iff
   844 mod_add1_eq            -> mod_add_eq
   845 mod_mult1_eq           -> mod_mult_right_eq
   846 mod_mult1_eq'          -> mod_mult_left_eq
   847 mod_mult_distrib_mod   -> mod_mult_eq
   848 nat_mod_add_left_eq    -> mod_add_left_eq
   849 nat_mod_add_right_eq   -> mod_add_right_eq
   850 nat_mod_div_trivial    -> mod_div_trivial
   851 nat_mod_mod_trivial    -> mod_mod_trivial
   852 zdiv_zadd_self1        -> div_add_self1
   853 zdiv_zadd_self2        -> div_add_self2
   854 zdiv_zmult_self1       -> div_mult_self2_is_id
   855 zdiv_zmult_self2       -> div_mult_self1_is_id
   856 zdvd_triv_left         -> dvd_triv_left
   857 zdvd_triv_right        -> dvd_triv_right
   858 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   859 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   860 zmod_zadd_left_eq      -> mod_add_left_eq
   861 zmod_zadd_right_eq     -> mod_add_right_eq
   862 zmod_zadd_self1        -> mod_add_self1
   863 zmod_zadd_self2        -> mod_add_self2
   864 zmod_zadd1_eq          -> mod_add_eq
   865 zmod_zdiff1_eq         -> mod_diff_eq
   866 zmod_zdvd_zmod         -> mod_mod_cancel
   867 zmod_zmod_cancel       -> mod_mod_cancel
   868 zmod_zmult_self1       -> mod_mult_self2_is_0
   869 zmod_zmult_self2       -> mod_mult_self1_is_0
   870 zmod_1                 -> mod_by_1
   871 zdiv_1                 -> div_by_1
   872 zdvd_abs1              -> abs_dvd_iff
   873 zdvd_abs2              -> dvd_abs_iff
   874 zdvd_refl              -> dvd_refl
   875 zdvd_trans             -> dvd_trans
   876 zdvd_zadd              -> dvd_add
   877 zdvd_zdiff             -> dvd_diff
   878 zdvd_zminus_iff        -> dvd_minus_iff
   879 zdvd_zminus2_iff       -> minus_dvd_iff
   880 zdvd_zmultD            -> dvd_mult_right
   881 zdvd_zmultD2           -> dvd_mult_left
   882 zdvd_zmult_mono        -> mult_dvd_mono
   883 zdvd_0_right           -> dvd_0_right
   884 zdvd_0_left            -> dvd_0_left_iff
   885 zdvd_1_left            -> one_dvd
   886 zminus_dvd_iff         -> minus_dvd_iff
   887 
   888 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   889 
   890 * The real numbers offer decimal input syntax: 12.34 is translated
   891 into 1234/10^2. This translation is not reversed upon output.
   892 
   893 * Theory Library/Polynomial defines an abstract type 'a poly of
   894 univariate polynomials with coefficients of type 'a.  In addition to
   895 the standard ring operations, it also supports div and mod.  Code
   896 generation is also supported, using list-style constructors.
   897 
   898 * Theory Library/Inner_Product defines a class of real_inner for real
   899 inner product spaces, with an overloaded operation inner :: 'a => 'a
   900 => real.  Class real_inner is a subclass of real_normed_vector from
   901 theory RealVector.
   902 
   903 * Theory Library/Product_Vector provides instances for the product
   904 type 'a * 'b of several classes from RealVector and Inner_Product.
   905 Definitions of addition, subtraction, scalar multiplication, norms,
   906 and inner products are included.
   907 
   908 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   909 addition to the field operations, numerals and case syntax are also
   910 supported.
   911 
   912 * Theory Library/Diagonalize provides constructive version of Cantor's
   913 first diagonalization argument.
   914 
   915 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   916 zlcm (for int); carried together from various gcd/lcm developements in
   917 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   918 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   919 may recover tupled syntax as follows:
   920 
   921     hide (open) const gcd
   922     abbreviation gcd where
   923       "gcd == (%(a, b). GCD.gcd a b)"
   924     notation (output)
   925       GCD.gcd ("gcd '(_, _')")
   926 
   927 The same works for lcm, zgcd, zlcm.
   928 
   929 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   930 instantiations for algebraic structures.  Removed some duplicate
   931 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   932 
   933 * ML antiquotation @{code} takes a constant as argument and generates
   934 corresponding code in background and inserts name of the corresponding
   935 resulting ML value/function/datatype constructor binding in place.
   936 All occurrences of @{code} with a single ML block are generated
   937 simultaneously.  Provides a generic and safe interface for
   938 instrumentalizing code generation.  See
   939 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   940 In future you ought to refrain from ad-hoc compiling generated SML
   941 code on the ML toplevel.  Note that (for technical reasons) @{code}
   942 cannot refer to constants for which user-defined serializations are
   943 set.  Refer to the corresponding ML counterpart directly in that
   944 cases.
   945 
   946 * Command 'rep_datatype': instead of theorem names the command now
   947 takes a list of terms denoting the constructors of the type to be
   948 represented as datatype.  The characteristic theorems have to be
   949 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   950 have disappeared in favour of existing ones:
   951 
   952     unit_induct                 ~> unit.induct
   953     prod_induct                 ~> prod.induct
   954     sum_induct                  ~> sum.induct
   955     Suc_Suc_eq                  ~> nat.inject
   956     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   957 
   958 
   959 *** HOL-Algebra ***
   960 
   961 * New locales for orders and lattices where the equivalence relation
   962 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   963 locales use a record structure with field eq for the equivalence.
   964 
   965 * New theory of factorial domains.
   966 
   967 * Units_l_inv and Units_r_inv are now simp rules by default.
   968 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   969 and/or r_inv will now also require deletion of these lemmas.
   970 
   971 * Renamed the following theorems, INCOMPATIBILITY:
   972 
   973 UpperD ~> Upper_memD
   974 LowerD ~> Lower_memD
   975 least_carrier ~> least_closed
   976 greatest_carrier ~> greatest_closed
   977 greatest_Lower_above ~> greatest_Lower_below
   978 one_zero ~> carrier_one_zero
   979 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   980 
   981 
   982 *** HOL-Nominal ***
   983 
   984 * Nominal datatypes can now contain type-variables.
   985 
   986 * Commands 'nominal_inductive' and 'equivariance' work with local
   987 theory targets.
   988 
   989 * Nominal primrec can now works with local theory targets and its
   990 specification syntax now conforms to the general format as seen in
   991 'inductive' etc.
   992 
   993 * Method "perm_simp" honours the standard simplifier attributes
   994 (no_asm), (no_asm_use) etc.
   995 
   996 * The new predicate #* is defined like freshness, except that on the
   997 left hand side can be a set or list of atoms.
   998 
   999 * Experimental command 'nominal_inductive2' derives strong induction
  1000 principles for inductive definitions.  In contrast to
  1001 'nominal_inductive', which can only deal with a fixed number of
  1002 binders, it can deal with arbitrary expressions standing for sets of
  1003 atoms to be avoided.  The only inductive definition we have at the
  1004 moment that needs this generalisation is the typing rule for Lets in
  1005 the algorithm W:
  1006 
  1007  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1008  -----------------------------------------------------------------
  1009          Gamma |- Let x be t1 in t2 : T2
  1010 
  1011 In this rule one wants to avoid all the binders that are introduced by
  1012 "close Gamma T1".  We are looking for other examples where this
  1013 feature might be useful.  Please let us know.
  1014 
  1015 
  1016 *** HOLCF ***
  1017 
  1018 * Reimplemented the simplification procedure for proving continuity
  1019 subgoals.  The new simproc is extensible; users can declare additional
  1020 continuity introduction rules with the attribute [cont2cont].
  1021 
  1022 * The continuity simproc now uses a different introduction rule for
  1023 solving continuity subgoals on terms with lambda abstractions.  In
  1024 some rare cases the new simproc may fail to solve subgoals that the
  1025 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1026 Potential INCOMPATIBILITY.
  1027 
  1028 * Command 'fixrec': specification syntax now conforms to the general
  1029 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1030 examples.  INCOMPATIBILITY.
  1031 
  1032 
  1033 *** ZF ***
  1034 
  1035 * Proof of Zorn's Lemma for partial orders.
  1036 
  1037 
  1038 *** ML ***
  1039 
  1040 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1041 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1042 depends on multithreading, so timouts will not work before Poly/ML
  1043 5.2.1!
  1044 
  1045 * High-level support for concurrent ML programming, see
  1046 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1047 particularly convenient to organize independent functional
  1048 computations.  The concept of "synchronized variables" provides a
  1049 higher-order interface for components with shared state, avoiding the
  1050 delicate details of mutexes and condition variables.  (Requires
  1051 Poly/ML 5.2.1 or later.)
  1052 
  1053 * ML bindings produced via Isar commands are stored within the Isar
  1054 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1055 become thread-safe and work with undo as expected (concerning
  1056 top-level bindings, not side-effects on global references).
  1057 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1058 compiler at runtime; really global bindings need to be given outside a
  1059 theory.  (Requires Poly/ML 5.2 or later.)
  1060 
  1061 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1062 context.  Top-level ML bindings are stored within the proof context in
  1063 a purely sequential fashion, disregarding the nested proof structure.
  1064 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1065 proof.  (Requires Poly/ML 5.2 or later.)
  1066 
  1067 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1068 and Method.setup, as well as Isar commands 'attribute_setup' and
  1069 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1070 existing code accordingly, or use plain 'setup' together with old
  1071 Method.add_method.
  1072 
  1073 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1074 to 'a -> thm, while results are always tagged with an authentic oracle
  1075 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1076 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1077 accordingly.  Note that extra performance may be gained by producing
  1078 the cterm carefully, avoiding slow Thm.cterm_of.
  1079 
  1080 * Simplified interface for defining document antiquotations via
  1081 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1082 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1083 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1084 examples.
  1085 
  1086 * More systematic treatment of long names, abstract name bindings, and
  1087 name space operations.  Basic operations on qualified names have been
  1088 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1089 Long_Name.append.  Old type bstring has been mostly replaced by
  1090 abstract type binding (see structure Binding), which supports precise
  1091 qualification by packages and local theory targets, as well as proper
  1092 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1093 bstring values into Binding.name, or better pass through abstract
  1094 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1095 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1096 
  1097 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1098 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1099 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1100 
  1101 * Disposed old type and term read functions (Sign.read_def_typ,
  1102 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1103 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1104 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1105 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1106 resort for legacy applications.
  1107 
  1108 * Disposed old declarations, tactics, tactic combinators that refer to
  1109 the simpset or claset of an implicit theory (such as Addsimps,
  1110 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1111 embedded ML text, or local_simpset_of with a proper context passed as
  1112 explicit runtime argument.
  1113 
  1114 * Rules and tactics that read instantiations (read_instantiate,
  1115 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1116 context, which is required for parsing and type-checking.  Moreover,
  1117 the variables are specified as plain indexnames, not string encodings
  1118 thereof.  INCOMPATIBILITY.
  1119 
  1120 * Generic Toplevel.add_hook interface allows to analyze the result of
  1121 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1122 for theorem dependency output of transactions resulting in a new
  1123 theory state.
  1124 
  1125 * ML antiquotations: block-structured compilation context indicated by
  1126 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1127 
  1128   @{binding name}                         - basic name binding
  1129   @{let ?pat = term}                      - term abbreviation (HO matching)
  1130   @{note name = fact}                     - fact abbreviation
  1131   @{thm fact}                             - singleton fact (with attributes)
  1132   @{thms fact}                            - general fact (with attributes)
  1133   @{lemma prop by method}                 - singleton goal
  1134   @{lemma prop by meth1 meth2}            - singleton goal
  1135   @{lemma prop1 ... propN by method}      - general goal
  1136   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1137   @{lemma (open) ...}                     - open derivation
  1138 
  1139 
  1140 *** System ***
  1141 
  1142 * The Isabelle "emacs" tool provides a specific interface to invoke
  1143 Proof General / Emacs, with more explicit failure if that is not
  1144 installed (the old isabelle-interface script silently falls back on
  1145 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1146 installation location of the Proof General distribution.
  1147 
  1148 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1149 the Isabelle process into a JVM/Scala application.  See
  1150 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1151 process wrapper has been discontinued.)
  1152 
  1153 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1154 
  1155 * Various status messages (with exact source position information) are
  1156 emitted, if proper markup print mode is enabled.  This allows
  1157 user-interface components to provide detailed feedback on internal
  1158 prover operations.
  1159 
  1160 
  1161 
  1162 New in Isabelle2008 (June 2008)
  1163 -------------------------------
  1164 
  1165 *** General ***
  1166 
  1167 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1168 and updated, with formally checked references as hyperlinks.
  1169 
  1170 * Theory loader: use_thy (and similar operations) no longer set the
  1171 implicit ML context, which was occasionally hard to predict and in
  1172 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1173 provides a proper context already.
  1174 
  1175 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1176 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1177 'use' within a theory file will do the job.
  1178 
  1179 * Name space merge now observes canonical order, i.e. the second space
  1180 is inserted into the first one, while existing entries in the first
  1181 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1182 swap theory imports.
  1183 
  1184 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1185 INCOMPATIBILITY in identifier syntax etc.
  1186 
  1187 * Outer syntax: string tokens no longer admit escaped white space,
  1188 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1189 white space without escapes.
  1190 
  1191 * Outer syntax: string tokens may contain arbitrary character codes
  1192 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1193 "foo_bar".
  1194 
  1195 
  1196 *** Pure ***
  1197 
  1198 * Context-dependent token translations.  Default setup reverts locally
  1199 fixed variables, and adds hilite markup for undeclared frees.
  1200 
  1201 * Unused theorems can be found using the new command 'unused_thms'.
  1202 There are three ways of invoking it:
  1203 
  1204 (1) unused_thms
  1205      Only finds unused theorems in the current theory.
  1206 
  1207 (2) unused_thms thy_1 ... thy_n -
  1208      Finds unused theorems in the current theory and all of its ancestors,
  1209      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1210 
  1211 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1212      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1213      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1214      their ancestors.
  1215 
  1216 In order to increase the readability of the list produced by
  1217 unused_thms, theorems that have been created by a particular instance
  1218 of a theory command such as 'inductive' or 'function' are considered
  1219 to belong to the same "group", meaning that if at least one theorem in
  1220 this group is used, the other theorems in the same group are no longer
  1221 reported as unused.  Moreover, if all theorems in the group are
  1222 unused, only one theorem in the group is displayed.
  1223 
  1224 Note that proof objects have to be switched on in order for
  1225 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1226 usually the case when using Proof General with the default settings).
  1227 
  1228 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1229 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1230 duplicate fact bindings, or even accidental fact duplications.  Note
  1231 that tools may maintain dynamically scoped facts systematically, using
  1232 PureThy.add_thms_dynamic.
  1233 
  1234 * Command 'hide' now allows to hide from "fact" name space as well.
  1235 
  1236 * Eliminated destructive theorem database, simpset, claset, and
  1237 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1238 update of theories within ML code.
  1239 
  1240 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1241 INCOMPATIBILITY, object-logics depending on former Pure require
  1242 additional setup PureThy.old_appl_syntax_setup; object-logics
  1243 depending on former CPure need to refer to Pure.
  1244 
  1245 * Commands 'use' and 'ML' are now purely functional, operating on
  1246 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1247 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1248 INCOMPATIBILITY.
  1249 
  1250 * Command 'setup': discontinued implicit version with ML reference.
  1251 
  1252 * Instantiation target allows for simultaneous specification of class
  1253 instance operations together with an instantiation proof.
  1254 Type-checking phase allows to refer to class operations uniformly.
  1255 See src/HOL/Complex/Complex.thy for an Isar example and
  1256 src/HOL/Library/Eval.thy for an ML example.
  1257 
  1258 * Indexing of literal facts: be more serious about including only
  1259 facts from the visible specification/proof context, but not the
  1260 background context (locale etc.).  Affects `prop` notation and method
  1261 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1262 situations.
  1263 
  1264 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1265 "(open)" option, which used to expose internal bound variables to the
  1266 proof text.
  1267 
  1268 * Isar statements: removed obsolete case "rule_context".
  1269 INCOMPATIBILITY, better use explicit fixes/assumes.
  1270 
  1271 * Locale proofs: default proof step now includes 'unfold_locales';
  1272 hence 'proof' without argument may be used to unfold locale
  1273 predicates.
  1274 
  1275 
  1276 *** Document preparation ***
  1277 
  1278 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1279 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1280 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1281 spot); renamed link color from "darkblue" to "linkcolor" (default
  1282 value unchanged, can be redefined via \definecolor); no longer sets
  1283 "a4paper" option (unnecessary or even intrusive).
  1284 
  1285 * Antiquotation @{lemma A method} proves proposition A by the given
  1286 method (either a method name or a method name plus (optional) method
  1287 arguments in parentheses) and prints A just like @{prop A}.
  1288 
  1289 
  1290 *** HOL ***
  1291 
  1292 * New primrec package.  Specification syntax conforms in style to
  1293 definition/function/....  No separate induction rule is provided.  The
  1294 "primrec" command distinguishes old-style and new-style specifications
  1295 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1296 When adjusting theories, beware: constants stemming from new-style
  1297 primrec specifications have authentic syntax.
  1298 
  1299 * Metis prover is now an order of magnitude faster, and also works
  1300 with multithreading.
  1301 
  1302 * Metis: the maximum number of clauses that can be produced from a
  1303 theorem is now given by the attribute max_clauses.  Theorems that
  1304 exceed this number are ignored, with a warning printed.
  1305 
  1306 * Sledgehammer no longer produces structured proofs by default. To
  1307 enable, declare [[sledgehammer_full = true]].  Attributes
  1308 reconstruction_modulus, reconstruction_sorts renamed
  1309 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1310 
  1311 * Method "induct_scheme" derives user-specified induction rules
  1312 from well-founded induction and completeness of patterns. This factors
  1313 out some operations that are done internally by the function package
  1314 and makes them available separately.  See
  1315 src/HOL/ex/Induction_Scheme.thy for examples.
  1316 
  1317 * More flexible generation of measure functions for termination
  1318 proofs: Measure functions can be declared by proving a rule of the
  1319 form "is_measure f" and giving it the [measure_function] attribute.
  1320 The "is_measure" predicate is logically meaningless (always true), and
  1321 just guides the heuristic.  To find suitable measure functions, the
  1322 termination prover sets up the goal "is_measure ?f" of the appropriate
  1323 type and generates all solutions by prolog-style backwards proof using
  1324 the declared rules.
  1325 
  1326 This setup also deals with rules like 
  1327 
  1328   "is_measure f ==> is_measure (list_size f)"
  1329 
  1330 which accommodates nested datatypes that recurse through lists.
  1331 Similar rules are predeclared for products and option types.
  1332 
  1333 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1334 
  1335   INCOMPATIBILITIES:
  1336 
  1337   - Definitions of overloaded constants on sets have to be replaced by
  1338     definitions on => and bool.
  1339 
  1340   - Some definitions of overloaded operators on sets can now be proved
  1341     using the definitions of the operators on => and bool.  Therefore,
  1342     the following theorems have been renamed:
  1343 
  1344       subset_def   -> subset_eq
  1345       psubset_def  -> psubset_eq
  1346       set_diff_def -> set_diff_eq
  1347       Compl_def    -> Compl_eq
  1348       Sup_set_def  -> Sup_set_eq
  1349       Inf_set_def  -> Inf_set_eq
  1350       sup_set_def  -> sup_set_eq
  1351       inf_set_def  -> inf_set_eq
  1352 
  1353   - Due to the incompleteness of the HO unification algorithm, some
  1354     rules such as subst may require manual instantiation, if some of
  1355     the unknowns in the rule is a set.
  1356 
  1357   - Higher order unification and forward proofs:
  1358     The proof pattern
  1359 
  1360       have "P (S::'a set)" <...>
  1361       then have "EX S. P S" ..
  1362 
  1363     no longer works (due to the incompleteness of the HO unification
  1364     algorithm) and must be replaced by the pattern
  1365 
  1366       have "EX S. P S"
  1367       proof
  1368         show "P S" <...>
  1369       qed
  1370 
  1371   - Calculational reasoning with subst (or similar rules):
  1372     The proof pattern
  1373 
  1374       have "P (S::'a set)" <...>
  1375       also have "S = T" <...>
  1376       finally have "P T" .
  1377 
  1378     no longer works (for similar reasons as the previous example) and
  1379     must be replaced by something like
  1380 
  1381       have "P (S::'a set)" <...>
  1382       moreover have "S = T" <...>
  1383       ultimately have "P T" by simp
  1384 
  1385   - Tactics or packages written in ML code:
  1386     Code performing pattern matching on types via
  1387 
  1388       Type ("set", [T]) => ...
  1389 
  1390     must be rewritten. Moreover, functions like strip_type or
  1391     binder_types no longer return the right value when applied to a
  1392     type of the form
  1393 
  1394       T1 => ... => Tn => U => bool
  1395 
  1396     rather than
  1397 
  1398       T1 => ... => Tn => U set
  1399 
  1400 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1401 Wellfounded_Relations to theory Wellfounded.
  1402 
  1403 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1404 
  1405 * Class finite no longer treats UNIV as class parameter.  Use class
  1406 enum from theory Library/Enum instead to achieve a similar effect.
  1407 INCOMPATIBILITY.
  1408 
  1409 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1410 and "Cons".  INCOMPATIBILITY.
  1411 
  1412 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1413 Potential INCOMPATIBILITY.
  1414 
  1415 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1416 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1417 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1418 
  1419 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1420 the same name in theory Orderings:
  1421 
  1422   less_trans
  1423   less_linear
  1424   le_imp_less_or_eq
  1425   le_less_trans
  1426   less_le_trans
  1427   less_not_sym
  1428   less_asym
  1429 
  1430 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1431 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1432 and different variable names.
  1433 
  1434 * Library/Option_ord.thy: Canonical order on option type.
  1435 
  1436 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1437 finite maps.
  1438 
  1439 * Library/Countable.thy: Type class for countable types.
  1440 
  1441 * Theory Int: The representation of numerals has changed.  The infix
  1442 operator BIT and the bit datatype with constructors B0 and B1 have
  1443 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1444 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1445 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1446 accordingly.
  1447 
  1448 * Theory Nat: definition of <= and < on natural numbers no longer
  1449 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1450 le_def and less_def have disappeared.  Consider lemmas not_less
  1451 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1452 
  1453 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1454 (whose purpose mainly is for various fold_set functionals) have been
  1455 abandoned in favor of the existing algebraic classes
  1456 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1457 lower_semilattice (resp. upper_semilattice) and linorder.
  1458 INCOMPATIBILITY.
  1459 
  1460 * Theory Transitive_Closure: induct and cases rules now declare proper
  1461 case_names ("base" and "step").  INCOMPATIBILITY.
  1462 
  1463 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1464 lattices.  The form set-specific version is available as
  1465 Inductive.lfp_ordinal_induct_set.
  1466 
  1467 * Renamed theorems "power.simps" to "power_int.simps".
  1468 INCOMPATIBILITY.
  1469 
  1470 * Class semiring_div provides basic abstract properties of semirings
  1471 with division and modulo operations.  Subsumes former class dvd_mod.
  1472 
  1473 * Merged theories IntDef, Numeral and IntArith into unified theory
  1474 Int.  INCOMPATIBILITY.
  1475 
  1476 * Theory Library/Code_Index: type "index" now represents natural
  1477 numbers rather than integers.  INCOMPATIBILITY.
  1478 
  1479 * New class "uminus" with operation "uminus" (split of from class
  1480 "minus" which now only has operation "minus", binary).
  1481 INCOMPATIBILITY.
  1482 
  1483 * Constants "card", "internal_split", "option_map" now with authentic
  1484 syntax.  INCOMPATIBILITY.
  1485 
  1486 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1487 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1488 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1489 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1490 Sup_set_def, le_def, less_def, option_map_def now with object
  1491 equality.  INCOMPATIBILITY.
  1492 
  1493 * Records. Removed K_record, and replaced it by pure lambda term
  1494 %x. c. The simplifier setup is now more robust against eta expansion.
  1495 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1496 
  1497 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1498 
  1499 * Library/ListVector: new theory of arithmetic vector operations.
  1500 
  1501 * Library/Order_Relation: new theory of various orderings as sets of
  1502 pairs.  Defines preorders, partial orders, linear orders and
  1503 well-orders on sets and on types.
  1504 
  1505 
  1506 *** ZF ***
  1507 
  1508 * Renamed some theories to allow to loading both ZF and HOL in the
  1509 same session:
  1510 
  1511   Datatype  -> Datatype_ZF
  1512   Inductive -> Inductive_ZF
  1513   Int       -> Int_ZF
  1514   IntDiv    -> IntDiv_ZF
  1515   Nat       -> Nat_ZF
  1516   List      -> List_ZF
  1517   Main      -> Main_ZF
  1518 
  1519 INCOMPATIBILITY: ZF theories that import individual theories below
  1520 Main might need to be adapted.  Regular theory Main is still
  1521 available, as trivial extension of Main_ZF.
  1522 
  1523 
  1524 *** ML ***
  1525 
  1526 * ML within Isar: antiquotation @{const name} or @{const
  1527 name(typargs)} produces statically-checked Const term.
  1528 
  1529 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1530 (of the same name).  Removed obsolete print command.
  1531 
  1532 * Removed obsolete "use_legacy_bindings" function.
  1533 
  1534 * The ``print mode'' is now a thread-local value derived from a global
  1535 template (the former print_mode reference), thus access becomes
  1536 non-critical.  The global print_mode reference is for session
  1537 management only; user-code should use print_mode_value,
  1538 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1539 
  1540 * Functions system/system_out provide a robust way to invoke external
  1541 shell commands, with propagation of interrupts (requires Poly/ML
  1542 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1543 
  1544 
  1545 *** System ***
  1546 
  1547 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1548 in accordance with Proof General 3.7, which prefers GNU emacs.
  1549 
  1550 * isatool tty runs Isabelle process with plain tty interaction;
  1551 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1552 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1553 
  1554 * isatool browser now works with Cygwin as well, using general
  1555 "javapath" function defined in Isabelle process environment.
  1556 
  1557 * YXML notation provides a simple and efficient alternative to
  1558 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1559 isatool yxml as described in the Isabelle system manual.
  1560 
  1561 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1562 provides general wrapper for managing an Isabelle process in a robust
  1563 fashion, with ``cooked'' output from stdin/stderr.
  1564 
  1565 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1566 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1567 
  1568 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1569 way of changing the user's settings is via
  1570 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1571 script.
  1572 
  1573 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1574 cores of the underlying machine, which is a good starting point for
  1575 optimal performance tuning.  The corresponding usedir option -M allows
  1576 "max" as an alias for "0".  WARNING: does not work on certain versions
  1577 of Mac OS (with Poly/ML 5.1).
  1578 
  1579 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1580 adverse effect of Isabelle flooding interactive front-ends (notably
  1581 ProofGeneral / XEmacs).
  1582 
  1583 
  1584 
  1585 New in Isabelle2007 (November 2007)
  1586 -----------------------------------
  1587 
  1588 *** General ***
  1589 
  1590 * More uniform information about legacy features, notably a
  1591 warning/error of "Legacy feature: ...", depending on the state of the
  1592 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1593 legacy features will disappear eventually.
  1594 
  1595 * Theory syntax: the header format ``theory A = B + C:'' has been
  1596 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1597 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1598 
  1599 * Theory syntax: the old non-Isar theory file format has been
  1600 discontinued altogether.  Note that ML proof scripts may still be used
  1601 with Isar theories; migration is usually quite simple with the ML
  1602 function use_legacy_bindings.  INCOMPATIBILITY.
  1603 
  1604 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1605 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1606 quotes.
  1607 
  1608 * Theory loader: be more serious about observing the static theory
  1609 header specifications (including optional directories), but not the
  1610 accidental file locations of previously successful loads.  The strict
  1611 update policy of former update_thy is now already performed by
  1612 use_thy, so the former has been removed; use_thys updates several
  1613 theories simultaneously, just as 'imports' within a theory header
  1614 specification, but without merging the results.  Potential
  1615 INCOMPATIBILITY: may need to refine theory headers and commands
  1616 ROOT.ML which depend on load order.
  1617 
  1618 * Theory loader: optional support for content-based file
  1619 identification, instead of the traditional scheme of full physical
  1620 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1621 (cf. the system manual).  The new scheme allows to work with
  1622 non-finished theories in persistent session images, such that source
  1623 files may be moved later on without requiring reloads.
  1624 
  1625 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1626 file (with the same base name as the theory) are considered a legacy
  1627 feature, which will disappear eventually. Even now, the theory loader
  1628 no longer maintains dependencies on such files.
  1629 
  1630 * Syntax: the scope for resolving ambiguities via type-inference is
  1631 now limited to individual terms, instead of whole simultaneous
  1632 specifications as before. This greatly reduces the complexity of the
  1633 syntax module and improves flexibility by separating parsing and
  1634 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1635 'fixes' etc.) are required in rare situations.
  1636 
  1637 * Syntax: constants introduced by new-style packages ('definition',
  1638 'abbreviation' etc.) are passed through the syntax module in
  1639 ``authentic mode''. This means that associated mixfix annotations
  1640 really stick to such constants, independently of potential name space
  1641 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1642 trees are represented slightly differently, may need to adapt syntax
  1643 translations accordingly. Use CONST marker in 'translations' and
  1644 @{const_syntax} antiquotation in 'parse_translation' etc.
  1645 
  1646 * Legacy goal package: reduced interface to the bare minimum required
  1647 to keep existing proof scripts running.  Most other user-level
  1648 functions are now part of the OldGoals structure, which is *not* open
  1649 by default (consider isatool expandshort before open OldGoals).
  1650 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1651 these tend to cause confusion about the actual goal (!) context being
  1652 used here, which is not necessarily the same as the_context().
  1653 
  1654 * Command 'find_theorems': supports "*" wild-card in "name:"
  1655 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1656 support a specific search form (see ProofGeneral/CHANGES).
  1657 
  1658 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1659 by default, which means that "prems" (and also "fixed variables") are
  1660 suppressed from proof state output.  Note that the ProofGeneral
  1661 settings mechanism allows to change and save options persistently, but
  1662 older versions of Isabelle will fail to start up if a negative prems
  1663 limit is imposed.
  1664 
  1665 * Local theory targets may be specified by non-nested blocks of
  1666 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1667 contain definitions, theorems etc., including any derived mechanism
  1668 that has been implemented on top of these primitives.  This concept
  1669 generalizes the existing ``theorem (in ...)'' towards more versatility
  1670 and scalability.
  1671 
  1672 * Proof General interface: proper undo of final 'end' command;
  1673 discontinued Isabelle/classic mode (ML proof scripts).
  1674 
  1675 
  1676 *** Document preparation ***
  1677 
  1678 * Added antiquotation @{theory name} which prints the given name,
  1679 after checking that it refers to a valid ancestor theory in the
  1680 current context.
  1681 
  1682 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1683 check the given source text as ML type/structure, printing verbatim.
  1684 
  1685 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1686 "c args == rhs" given in the current context.  (Any number of
  1687 arguments may be given on the LHS.)
  1688 
  1689 
  1690 *** Pure ***
  1691 
  1692 * The 'class' package offers a combination of axclass and locale to
  1693 achieve Haskell-like type classes in Isabelle.  Definitions and
  1694 theorems within a class context produce both relative results (with
  1695 implicit parameters according to the locale context), and polymorphic
  1696 constants with qualified polymorphism (according to the class
  1697 context).  Within the body context of a 'class' target, a separate
  1698 syntax layer ("user space type system") takes care of converting
  1699 between global polymorphic consts and internal locale representation.
  1700 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1701 "isatool doc classes" provides a tutorial.
  1702 
  1703 * Generic code generator framework allows to generate executable
  1704 code for ML and Haskell (including Isabelle classes).  A short usage
  1705 sketch:
  1706 
  1707     internal compilation:
  1708         export_code <list of constants (term syntax)> in SML
  1709     writing SML code to a file:
  1710         export_code <list of constants (term syntax)> in SML <filename>
  1711     writing OCaml code to a file:
  1712         export_code <list of constants (term syntax)> in OCaml <filename>
  1713     writing Haskell code to a bunch of files:
  1714         export_code <list of constants (term syntax)> in Haskell <filename>
  1715 
  1716     evaluating closed propositions to True/False using code generation:
  1717         method ``eval''
  1718 
  1719 Reasonable default setup of framework in HOL.
  1720 
  1721 Theorem attributs for selecting and transforming function equations theorems:
  1722 
  1723     [code fun]:        select a theorem as function equation for a specific constant
  1724     [code fun del]:    deselect a theorem as function equation for a specific constant
  1725     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1726     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1727 
  1728 User-defined serializations (target in {SML, OCaml, Haskell}):
  1729 
  1730     code_const <and-list of constants (term syntax)>
  1731       {(target) <and-list of const target syntax>}+
  1732 
  1733     code_type <and-list of type constructors>
  1734       {(target) <and-list of type target syntax>}+
  1735 
  1736     code_instance <and-list of instances>
  1737       {(target)}+
  1738         where instance ::= <type constructor> :: <class>
  1739 
  1740     code_class <and_list of classes>
  1741       {(target) <and-list of class target syntax>}+
  1742         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1743 
  1744 code_instance and code_class only are effective to target Haskell.
  1745 
  1746 For example usage see src/HOL/ex/Codegenerator.thy and
  1747 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1748 generation from Isabelle/HOL theories is available via "isatool doc
  1749 codegen".
  1750 
  1751 * Code generator: consts in 'consts_code' Isar commands are now
  1752 referred to by usual term syntax (including optional type
  1753 annotations).
  1754 
  1755 * Command 'no_translations' removes translation rules from theory
  1756 syntax.
  1757 
  1758 * Overloaded definitions are now actually checked for acyclic
  1759 dependencies.  The overloading scheme is slightly more general than
  1760 that of Haskell98, although Isabelle does not demand an exact
  1761 correspondence to type class and instance declarations.
  1762 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1763 exotic versions of overloading -- at the discretion of the user!
  1764 
  1765 Polymorphic constants are represented via type arguments, i.e. the
  1766 instantiation that matches an instance against the most general
  1767 declaration given in the signature.  For example, with the declaration
  1768 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1769 as c(nat).  Overloading is essentially simultaneous structural
  1770 recursion over such type arguments.  Incomplete specification patterns
  1771 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1772 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1773 Command 'print_theory' outputs the normalized system of recursive
  1774 equations, see section "definitions".
  1775 
  1776 * Configuration options are maintained within the theory or proof
  1777 context (with name and type bool/int/string), providing a very simple
  1778 interface to a poor-man's version of general context data.  Tools may
  1779 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1780 these values using Config.get etc.  Users may change options via an
  1781 associated attribute of the same name.  This form of context
  1782 declaration works particularly well with commands 'declare' or
  1783 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1784 very easy to avoid global references, which would not observe Isar
  1785 toplevel undo/redo and fail to work with multithreading.
  1786 
  1787 Various global ML references of Pure and HOL have been turned into
  1788 configuration options:
  1789 
  1790   Unify.search_bound		unify_search_bound
  1791   Unify.trace_bound		unify_trace_bound
  1792   Unify.trace_simp		unify_trace_simp
  1793   Unify.trace_types		unify_trace_types
  1794   Simplifier.simp_depth_limit	simp_depth_limit
  1795   Blast.depth_limit		blast_depth_limit
  1796   DatatypeProp.dtK		datatype_distinctness_limit
  1797   fast_arith_neq_limit  	fast_arith_neq_limit
  1798   fast_arith_split_limit	fast_arith_split_limit
  1799 
  1800 * Named collections of theorems may be easily installed as context
  1801 data using the functor NamedThmsFun (see also
  1802 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1803 attributes; there is also a toplevel print command.  This facility is
  1804 just a common case of general context data, which is the preferred way
  1805 for anything more complex than just a list of facts in canonical
  1806 order.
  1807 
  1808 * Isar: command 'declaration' augments a local theory by generic
  1809 declaration functions written in ML.  This enables arbitrary content
  1810 being added to the context, depending on a morphism that tells the
  1811 difference of the original declaration context wrt. the application
  1812 context encountered later on.
  1813 
  1814 * Isar: proper interfaces for simplification procedures.  Command
  1815 'simproc_setup' declares named simprocs (with match patterns, and body
  1816 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1817 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1818 
  1819 * Isar: an extra pair of brackets around attribute declarations
  1820 abbreviates a theorem reference involving an internal dummy fact,
  1821 which will be ignored later --- only the effect of the attribute on
  1822 the background context will persist.  This form of in-place
  1823 declarations is particularly useful with commands like 'declare' and
  1824 'using', for example ``have A using [[simproc a]] by simp''.
  1825 
  1826 * Isar: method "assumption" (and implicit closing of subproofs) now
  1827 takes simple non-atomic goal assumptions into account: after applying
  1828 an assumption as a rule the resulting subgoals are solved by atomic
  1829 assumption steps.  This is particularly useful to finish 'obtain'
  1830 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1831 without referring to the original premise "!!x. P x ==> thesis" in the
  1832 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1833 more permissive.
  1834 
  1835 * Isar: implicit use of prems from the Isar proof context is
  1836 considered a legacy feature.  Common applications like ``have A .''
  1837 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1838 referencing facts explicitly here improves readability and
  1839 maintainability of proof texts.
  1840 
  1841 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1842 the obtained context from the course of reasoning!  For example:
  1843 
  1844   assume "EX x y. A x & B y"   -- "any previous fact"
  1845   then guess x and y by clarify
  1846 
  1847 This technique is potentially adventurous, depending on the facts and
  1848 proof tools being involved here.
  1849 
  1850 * Isar: known facts from the proof context may be specified as literal
  1851 propositions, using ASCII back-quote syntax.  This works wherever
  1852 named facts used to be allowed so far, in proof commands, proof
  1853 methods, attributes etc.  Literal facts are retrieved from the context
  1854 according to unification of type and term parameters.  For example,
  1855 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1856 theorems in the current context, then these are valid literal facts:
  1857 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1858 
  1859 There is also a proof method "fact" which does the same composition
  1860 for explicit goal states, e.g. the following proof texts coincide with
  1861 certain special cases of literal facts:
  1862 
  1863   have "A" by fact                 ==  note `A`
  1864   have "A ==> B" by fact           ==  note `A ==> B`
  1865   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1866   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1867 
  1868 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1869 outer syntax.  Thus symbolic identifiers may be used without
  1870 additional white space in declarations like this: ``assume *: A''.
  1871 
  1872 * Isar: 'print_facts' prints all local facts of the current context,
  1873 both named and unnamed ones.
  1874 
  1875 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1876 
  1877   def x == "t" and y == "u"
  1878 
  1879 * Isar: added command 'unfolding', which is structurally similar to
  1880 'using', but affects both the goal state and facts by unfolding given
  1881 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1882 'unfolded' attribute may be replaced by first-class proof text.
  1883 
  1884 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1885 and command 'unfolding' now all support object-level equalities
  1886 (potentially conditional).  The underlying notion of rewrite rule is
  1887 analogous to the 'rule_format' attribute, but *not* that of the
  1888 Simplifier (which is usually more generous).
  1889 
  1890 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1891 premises of a theorem by n. Useful in conjunction with drule.
  1892 
  1893 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1894 method expression within a sandbox consisting of the first N
  1895 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1896 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1897 simplifies all new goals that emerge from applying rule foo to the
  1898 originally first one.
  1899 
  1900 * Isar: schematic goals are no longer restricted to higher-order
  1901 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1902 expected.
  1903 
  1904 * Isar: the conclusion of a long theorem statement is now either
  1905 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1906 (essentially a disjunction of cases with local parameters and
  1907 assumptions).  The latter allows to express general elimination rules
  1908 adequately; in this notation common elimination rules look like this:
  1909 
  1910   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1911     assumes "EX x. P x"
  1912     obtains x where "P x"
  1913 
  1914   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1915     assumes "A & B"
  1916     obtains A and B
  1917 
  1918   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1919     assumes "A | B"
  1920     obtains
  1921       A
  1922     | B
  1923 
  1924 The subsequent classical rules even refer to the formal "thesis"
  1925 explicitly:
  1926 
  1927   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1928     obtains "~ thesis"
  1929 
  1930   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1931     obtains "thesis ==> something"
  1932 
  1933 The actual proof of an 'obtains' statement is analogous to that of the
  1934 Isar proof element 'obtain', only that there may be several cases.
  1935 Optional case names may be specified in parentheses; these will be
  1936 available both in the present proof and as annotations in the
  1937 resulting rule, for later use with the 'cases' method (cf. attribute
  1938 case_names).
  1939 
  1940 * Isar: the assumptions of a long theorem statement are available as
  1941 "assms" fact in the proof context.  This is more appropriate than the
  1942 (historical) "prems", which refers to all assumptions of the current
  1943 context, including those from the target locale, proof body etc.
  1944 
  1945 * Isar: 'print_statement' prints theorems from the current theory or
  1946 proof context in long statement form, according to the syntax of a
  1947 top-level lemma.
  1948 
  1949 * Isar: 'obtain' takes an optional case name for the local context
  1950 introduction rule (default "that").
  1951 
  1952 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1953 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1954 to occur.
  1955 
  1956 * Pure: syntax "CONST name" produces a fully internalized constant
  1957 according to the current context.  This is particularly useful for
  1958 syntax translations that should refer to internal constant
  1959 representations independently of name spaces.
  1960 
  1961 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1962 instead of "FOO ". This allows multiple binder declarations to coexist
  1963 in the same context.  INCOMPATIBILITY.
  1964 
  1965 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1966 primitive that also works in a locale context (both for constants and
  1967 fixed variables). Type declaration and internal syntactic representation
  1968 of given constants retrieved from the context. Likewise, the
  1969 'no_notation' command allows to remove given syntax annotations from the
  1970 current context.
  1971 
  1972 * Isar/locales: new derived specification elements 'axiomatization',
  1973 'definition', 'abbreviation', which support type-inference, admit
  1974 object-level specifications (equality, equivalence).  See also the
  1975 isar-ref manual.  Examples:
  1976 
  1977   axiomatization
  1978     eq  (infix "===" 50) where
  1979     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1980 
  1981   definition "f x y = x + y + 1"
  1982   definition g where "g x = f x x"
  1983 
  1984   abbreviation
  1985     neq  (infix "=!=" 50) where
  1986     "x =!= y == ~ (x === y)"
  1987 
  1988 These specifications may be also used in a locale context.  Then the
  1989 constants being introduced depend on certain fixed parameters, and the
  1990 constant name is qualified by the locale base name.  An internal
  1991 abbreviation takes care for convenient input and output, making the
  1992 parameters implicit and using the original short name.  See also
  1993 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1994 entities from a monomorphic theory.
  1995 
  1996 Presently, abbreviations are only available 'in' a target locale, but
  1997 not inherited by general import expressions.  Also note that
  1998 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1999 'translations' in common applications.  The "no_abbrevs" print mode
  2000 prevents folding of abbreviations in term output.
  2001 
  2002 Concrete syntax is attached to specified constants in internal form,
  2003 independently of name spaces.  The parse tree representation is
  2004 slightly different -- use 'notation' instead of raw 'syntax', and
  2005 'translations' with explicit "CONST" markup to accommodate this.
  2006 
  2007 * Pure/Isar: unified syntax for new-style specification mechanisms
  2008 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2009 full type inference and dummy patterns ("_").  For example:
  2010 
  2011   definition "K x _ = x"
  2012 
  2013   inductive conj for A B
  2014   where "A ==> B ==> conj A B"
  2015 
  2016 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2017 the current context.  Print mode "no_abbrevs" prevents inversion of
  2018 abbreviations on output.
  2019 
  2020 * Isar/locales: improved parameter handling: use of locales "var" and
  2021 "struct" no longer necessary; - parameter renamings are no longer
  2022 required to be injective.  For example, this allows to define
  2023 endomorphisms as locale endom = homom mult mult h.
  2024 
  2025 * Isar/locales: changed the way locales with predicates are defined.
  2026 Instead of accumulating the specification, the imported expression is
  2027 now an interpretation.  INCOMPATIBILITY: different normal form of
  2028 locale expressions.  In particular, in interpretations of locales with
  2029 predicates, goals repesenting already interpreted fragments are not
  2030 removed automatically.  Use methods `intro_locales' and
  2031 `unfold_locales'; see below.
  2032 
  2033 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2034 provide backward reasoning on locales predicates.  The methods are
  2035 aware of interpretations and discharge corresponding goals.
  2036 `intro_locales' is less aggressive then `unfold_locales' and does not
  2037 unfold predicates to assumptions.
  2038 
  2039 * Isar/locales: the order in which locale fragments are accumulated
  2040 has changed.  This enables to override declarations from fragments due
  2041 to interpretations -- for example, unwanted simp rules.
  2042 
  2043 * Isar/locales: interpretation in theories and proof contexts has been
  2044 extended.  One may now specify (and prove) equations, which are
  2045 unfolded in interpreted theorems.  This is useful for replacing
  2046 defined concepts (constants depending on locale parameters) by
  2047 concepts already existing in the target context.  Example:
  2048 
  2049   interpretation partial_order ["op <= :: [int, int] => bool"]
  2050     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2051 
  2052 Typically, the constant `partial_order.less' is created by a
  2053 definition specification element in the context of locale
  2054 partial_order.
  2055 
  2056 * Method "induct": improved internal context management to support
  2057 local fixes and defines on-the-fly. Thus explicit meta-level
  2058 connectives !!  and ==> are rarely required anymore in inductive goals
  2059 (using object-logic connectives for this purpose has been long
  2060 obsolete anyway). Common proof patterns are explained in
  2061 src/HOL/Induct/Common_Patterns.thy, see also
  2062 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2063 examples.
  2064 
  2065 * Method "induct": improved handling of simultaneous goals. Instead of
  2066 introducing object-level conjunction, the statement is now split into
  2067 several conclusions, while the corresponding symbolic cases are nested
  2068 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2069 see src/HOL/Induct/Common_Patterns.thy, for example.
  2070 
  2071 * Method "induct": mutual induction rules are now specified as a list
  2072 of rule sharing the same induction cases. HOL packages usually provide
  2073 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2074 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2075 mutual induction rules differently, i.e. like this:
  2076 
  2077   (induct rule: foo_bar.inducts)
  2078   (induct set: foo bar)
  2079   (induct pred: foo bar)
  2080   (induct type: foo bar)
  2081 
  2082 The ML function ProjectRule.projections turns old-style rules into the
  2083 new format.
  2084 
  2085 * Method "coinduct": dual of induction, see
  2086 src/HOL/Library/Coinductive_List.thy for various examples.
  2087 
  2088 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2089 considered a legacy feature.
  2090 
  2091 * Attribute "symmetric" produces result with standardized schematic
  2092 variables (index 0).  Potential INCOMPATIBILITY.
  2093 
  2094 * Simplifier: by default the simplifier trace only shows top level
  2095 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2096 default. Thus there is less danger of being flooded by the trace. The
  2097 trace indicates where parts have been suppressed.
  2098   
  2099 * Provers/classical: removed obsolete classical version of elim_format
  2100 attribute; classical elim/dest rules are now treated uniformly when
  2101 manipulating the claset.
  2102 
  2103 * Provers/classical: stricter checks to ensure that supplied intro,
  2104 dest and elim rules are well-formed; dest and elim rules must have at
  2105 least one premise.
  2106 
  2107 * Provers/classical: attributes dest/elim/intro take an optional
  2108 weight argument for the rule (just as the Pure versions).  Weights are
  2109 ignored by automated tools, but determine the search order of single
  2110 rule steps.
  2111 
  2112 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2113 where the body does not mention the bound variable.  Note that dummy
  2114 patterns implicitly depend on their context of bounds, which makes
  2115 "{_. _}" match any set comprehension as expected.  Potential
  2116 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2117 constant "_idtdummy" in the binding position.
  2118 
  2119 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2120 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2121 for example "A -> B" => "Pi A (%_. B)".
  2122 
  2123 * Pure: 'class_deps' command visualizes the subclass relation, using
  2124 the graph browser tool.
  2125 
  2126 * Pure: 'print_theory' now suppresses certain internal declarations by
  2127 default; use '!' option for full details.
  2128 
  2129 
  2130 *** HOL ***
  2131 
  2132 * Method "metis" proves goals by applying the Metis general-purpose
  2133 resolution prover (see also http://gilith.com/software/metis/).
  2134 Examples are in the directory MetisExamples.  WARNING: the
  2135 Isabelle/HOL-Metis integration does not yet work properly with
  2136 multi-threading.
  2137   
  2138 * Command 'sledgehammer' invokes external automatic theorem provers as
  2139 background processes.  It generates calls to the "metis" method if
  2140 successful. These can be pasted into the proof.  Users do not have to
  2141 wait for the automatic provers to return.  WARNING: does not really
  2142 work with multi-threading.
  2143 
  2144 * New "auto_quickcheck" feature tests outermost goal statements for
  2145 potential counter-examples.  Controlled by ML references
  2146 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2147 5000 milliseconds).  Fails silently if statements is outside of
  2148 executable fragment, or any other codgenerator problem occurs.
  2149 
  2150 * New constant "undefined" with axiom "undefined x = undefined".
  2151 
  2152 * Added class "HOL.eq", allowing for code generation with polymorphic
  2153 equality.
  2154 
  2155 * Some renaming of class constants due to canonical name prefixing in
  2156 the new 'class' package:
  2157 
  2158     HOL.abs ~> HOL.abs_class.abs
  2159     HOL.divide ~> HOL.divide_class.divide
  2160     0 ~> HOL.zero_class.zero
  2161     1 ~> HOL.one_class.one
  2162     op + ~> HOL.plus_class.plus
  2163     op - ~> HOL.minus_class.minus
  2164     uminus ~> HOL.minus_class.uminus
  2165     op * ~> HOL.times_class.times
  2166     op < ~> HOL.ord_class.less
  2167     op <= > HOL.ord_class.less_eq
  2168     Nat.power ~> Power.power_class.power
  2169     Nat.size ~> Nat.size_class.size
  2170     Numeral.number_of ~> Numeral.number_class.number_of
  2171     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2172     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2173     Orderings.min ~> Orderings.ord_class.min
  2174     Orderings.max ~> Orderings.ord_class.max
  2175     Divides.op div ~> Divides.div_class.div
  2176     Divides.op mod ~> Divides.div_class.mod
  2177     Divides.op dvd ~> Divides.div_class.dvd
  2178 
  2179 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2180 
  2181 a) User-defined constants using any of the names "plus", "minus",
  2182 "times", "less" or "less_eq". The standard syntax translations for
  2183 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2184 names.
  2185 
  2186 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2187 INCOMPATIBILITY: use more specific names.
  2188 
  2189 c) Permutative equations (e.g. "a + b = b + a")
  2190 Since the change of names also changes the order of terms, permutative
  2191 rewrite rules may get applied in a different order. Experience shows
  2192 that this is rarely the case (only two adaptions in the whole Isabelle
  2193 distribution).  INCOMPATIBILITY: rewrite proofs
  2194 
  2195 d) ML code directly refering to constant names
  2196 This in general only affects hand-written proof tactics, simprocs and
  2197 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2198 Consider using @{const_name} antiquotation.
  2199 
  2200 * New class "default" with associated constant "default".
  2201 
  2202 * Function "sgn" is now overloaded and available on int, real, complex
  2203 (and other numeric types), using class "sgn".  Two possible defs of
  2204 sgn are given as equational assumptions in the classes sgn_if and
  2205 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2206 INCOMPATIBILITY.
  2207 
  2208 * Locale "partial_order" now unified with class "order" (cf. theory
  2209 Orderings), added parameter "less".  INCOMPATIBILITY.
  2210 
  2211 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2212 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2213 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2214 
  2215 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2216 changed order of proof goals in instance proofs.
  2217 
  2218 * The transitivity reasoner for partial and linear orders is set up
  2219 for classes "order" and "linorder".  Instances of the reasoner are available
  2220 in all contexts importing or interpreting the corresponding locales.
  2221 Method "order" invokes the reasoner separately; the reasoner
  2222 is also integrated with the Simplifier as a solver.  Diagnostic
  2223 command 'print_orders' shows the available instances of the reasoner
  2224 in the current context.
  2225 
  2226 * Localized monotonicity predicate in theory "Orderings"; integrated
  2227 lemmas max_of_mono and min_of_mono with this predicate.
  2228 INCOMPATIBILITY.
  2229 
  2230 * Formulation of theorem "dense" changed slightly due to integration
  2231 with new class dense_linear_order.
  2232 
  2233 * Uniform lattice theory development in HOL.
  2234 
  2235     constants "meet" and "join" now named "inf" and "sup"
  2236     constant "Meet" now named "Inf"
  2237 
  2238     classes "meet_semilorder" and "join_semilorder" now named
  2239       "lower_semilattice" and "upper_semilattice"
  2240     class "lorder" now named "lattice"
  2241     class "comp_lat" now named "complete_lattice"
  2242 
  2243     Instantiation of lattice classes allows explicit definitions
  2244     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2245 
  2246   INCOMPATIBILITY.  Theorem renames:
  2247 
  2248     meet_left_le            ~> inf_le1
  2249     meet_right_le           ~> inf_le2
  2250     join_left_le            ~> sup_ge1
  2251     join_right_le           ~> sup_ge2
  2252     meet_join_le            ~> inf_sup_ord
  2253     le_meetI                ~> le_infI
  2254     join_leI                ~> le_supI
  2255     le_meet                 ~> le_inf_iff
  2256     le_join                 ~> ge_sup_conv
  2257     meet_idempotent         ~> inf_idem
  2258     join_idempotent         ~> sup_idem
  2259     meet_comm               ~> inf_commute
  2260     join_comm               ~> sup_commute
  2261     meet_leI1               ~> le_infI1
  2262     meet_leI2               ~> le_infI2
  2263     le_joinI1               ~> le_supI1
  2264     le_joinI2               ~> le_supI2
  2265     meet_assoc              ~> inf_assoc
  2266     join_assoc              ~> sup_assoc
  2267     meet_left_comm          ~> inf_left_commute
  2268     meet_left_idempotent    ~> inf_left_idem
  2269     join_left_comm          ~> sup_left_commute
  2270     join_left_idempotent    ~> sup_left_idem
  2271     meet_aci                ~> inf_aci
  2272     join_aci                ~> sup_aci
  2273     le_def_meet             ~> le_iff_inf
  2274     le_def_join             ~> le_iff_sup
  2275     join_absorp2            ~> sup_absorb2
  2276     join_absorp1            ~> sup_absorb1
  2277     meet_absorp1            ~> inf_absorb1
  2278     meet_absorp2            ~> inf_absorb2
  2279     meet_join_absorp        ~> inf_sup_absorb
  2280     join_meet_absorp        ~> sup_inf_absorb
  2281     distrib_join_le         ~> distrib_sup_le
  2282     distrib_meet_le         ~> distrib_inf_le
  2283 
  2284     add_meet_distrib_left   ~> add_inf_distrib_left
  2285     add_join_distrib_left   ~> add_sup_distrib_left
  2286     is_join_neg_meet        ~> is_join_neg_inf
  2287     is_meet_neg_join        ~> is_meet_neg_sup
  2288     add_meet_distrib_right  ~> add_inf_distrib_right
  2289     add_join_distrib_right  ~> add_sup_distrib_right
  2290     add_meet_join_distribs  ~> add_sup_inf_distribs
  2291     join_eq_neg_meet        ~> sup_eq_neg_inf
  2292     meet_eq_neg_join        ~> inf_eq_neg_sup
  2293     add_eq_meet_join        ~> add_eq_inf_sup
  2294     meet_0_imp_0            ~> inf_0_imp_0
  2295     join_0_imp_0            ~> sup_0_imp_0
  2296     meet_0_eq_0             ~> inf_0_eq_0
  2297     join_0_eq_0             ~> sup_0_eq_0
  2298     neg_meet_eq_join        ~> neg_inf_eq_sup
  2299     neg_join_eq_meet        ~> neg_sup_eq_inf
  2300     join_eq_if              ~> sup_eq_if
  2301 
  2302     mono_meet               ~> mono_inf
  2303     mono_join               ~> mono_sup
  2304     meet_bool_eq            ~> inf_bool_eq
  2305     join_bool_eq            ~> sup_bool_eq
  2306     meet_fun_eq             ~> inf_fun_eq
  2307     join_fun_eq             ~> sup_fun_eq
  2308     meet_set_eq             ~> inf_set_eq
  2309     join_set_eq             ~> sup_set_eq
  2310     meet1_iff               ~> inf1_iff
  2311     meet2_iff               ~> inf2_iff
  2312     meet1I                  ~> inf1I
  2313     meet2I                  ~> inf2I
  2314     meet1D1                 ~> inf1D1
  2315     meet2D1                 ~> inf2D1
  2316     meet1D2                 ~> inf1D2
  2317     meet2D2                 ~> inf2D2
  2318     meet1E                  ~> inf1E
  2319     meet2E                  ~> inf2E
  2320     join1_iff               ~> sup1_iff
  2321     join2_iff               ~> sup2_iff
  2322     join1I1                 ~> sup1I1
  2323     join2I1                 ~> sup2I1
  2324     join1I1                 ~> sup1I1
  2325     join2I2                 ~> sup1I2
  2326     join1CI                 ~> sup1CI
  2327     join2CI                 ~> sup2CI
  2328     join1E                  ~> sup1E
  2329     join2E                  ~> sup2E
  2330 
  2331     is_meet_Meet            ~> is_meet_Inf
  2332     Meet_bool_def           ~> Inf_bool_def
  2333     Meet_fun_def            ~> Inf_fun_def
  2334     Meet_greatest           ~> Inf_greatest
  2335     Meet_lower              ~> Inf_lower
  2336     Meet_set_def            ~> Inf_set_def
  2337 
  2338     Sup_def                 ~> Sup_Inf
  2339     Sup_bool_eq             ~> Sup_bool_def
  2340     Sup_fun_eq              ~> Sup_fun_def
  2341     Sup_set_eq              ~> Sup_set_def
  2342 
  2343     listsp_meetI            ~> listsp_infI
  2344     listsp_meet_eq          ~> listsp_inf_eq
  2345 
  2346     meet_min                ~> inf_min
  2347     join_max                ~> sup_max
  2348 
  2349 * Added syntactic class "size"; overloaded constant "size" now has
  2350 type "'a::size ==> bool"
  2351 
  2352 * Internal reorganisation of `size' of datatypes: size theorems
  2353 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2354 simplification rules by default!); theorems "prod.size" now named
  2355 "*.size".
  2356 
  2357 * Class "div" now inherits from class "times" rather than "type".
  2358 INCOMPATIBILITY.
  2359 
  2360 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2361 Linorder etc.  have disappeared; operations defined in terms of
  2362 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2363 
  2364 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2365 
  2366 * HOL-Word: New extensive library and type for generic, fixed size
  2367 machine words, with arithemtic, bit-wise, shifting and rotating
  2368 operations, reflection into int, nat, and bool lists, automation for
  2369 linear arithmetic (by automatic reflection into nat or int), including
  2370 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2371 arithmetic type classes, supporting automatic simplification of
  2372 numerals on all operations.
  2373 
  2374 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2375 
  2376 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2377 
  2378 * Code generator library theories:
  2379   - Code_Integer represents HOL integers by big integer literals in target
  2380     languages.
  2381   - Code_Char represents HOL characters by character literals in target
  2382     languages.
  2383   - Code_Char_chr like Code_Char, but also offers treatment of character
  2384     codes; includes Code_Integer.
  2385   - Executable_Set allows to generate code for finite sets using lists.
  2386   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2387     denominator).
  2388   - Executable_Real implements a subset of real numbers, namly those
  2389     representable by rational numbers.
  2390   - Efficient_Nat implements natural numbers by integers, which in general will
  2391     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2392     includes Code_Integer.
  2393   - Code_Index provides an additional datatype index which is mapped to
  2394     target-language built-in integers.
  2395   - Code_Message provides an additional datatype message_string which is isomorphic to
  2396     strings; messages are mapped to target-language strings.
  2397 
  2398 * New package for inductive predicates
  2399 
  2400   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2401 
  2402     inductive
  2403       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2404       for z_1 :: U_1 and ... and z_n :: U_m
  2405     where
  2406       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2407     | ...
  2408 
  2409   with full support for type-inference, rather than
  2410 
  2411     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2412 
  2413     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2414     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2415 
  2416     inductive "s z_1 ... z_m"
  2417     intros
  2418       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2419       ...
  2420 
  2421   For backward compatibility, there is a wrapper allowing inductive
  2422   sets to be defined with the new package via
  2423 
  2424     inductive_set
  2425       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2426       for z_1 :: U_1 and ... and z_n :: U_m
  2427     where
  2428       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2429     | ...
  2430 
  2431   or
  2432 
  2433     inductive_set
  2434       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2435       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2436       for z_1 :: U_1 and ... and z_n :: U_m
  2437     where
  2438       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2439     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2440     | ...
  2441 
  2442   if the additional syntax "p ..." is required.
  2443 
  2444   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2445   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2446 
  2447   INCOMPATIBILITIES:
  2448 
  2449   - Since declaration and definition of inductive sets or predicates
  2450     is no longer separated, abbreviations involving the newly
  2451     introduced sets or predicates must be specified together with the
  2452     introduction rules after the 'where' keyword (see above), rather
  2453     than before the actual inductive definition.
  2454 
  2455   - The variables in induction and elimination rules are now
  2456     quantified in the order of their occurrence in the introduction
  2457     rules, rather than in alphabetical order. Since this may break
  2458     some proofs, these proofs either have to be repaired, e.g. by
  2459     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2460     statements of the form
  2461 
  2462       case (rule_i a_i_1 ... a_i_{k_i})
  2463 
  2464     or the old order of quantification has to be restored by explicitly adding
  2465     meta-level quantifiers in the introduction rules, i.e.
  2466 
  2467       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2468 
  2469   - The format of the elimination rules is now
  2470 
  2471       p z_1 ... z_m x_1 ... x_n ==>
  2472         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2473         ==> ... ==> P
  2474 
  2475     for predicates and
  2476 
  2477       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2478         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2479         ==> ... ==> P
  2480 
  2481     for sets rather than
  2482 
  2483       x : s z_1 ... z_m ==>
  2484         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2485         ==> ... ==> P
  2486 
  2487     This may require terms in goals to be expanded to n-tuples
  2488     (e.g. using case_tac or simplification with the split_paired_all
  2489     rule) before the above elimination rule is applicable.
  2490 
  2491   - The elimination or case analysis rules for (mutually) inductive
  2492     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2493     list of rules "p_1_..._p_k.elims" is no longer available.
  2494 
  2495 * New package "function"/"fun" for general recursive functions,
  2496 supporting mutual and nested recursion, definitions in local contexts,
  2497 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2498 for small examples, and the separate tutorial on the function
  2499 package. The old recdef "package" is still available as before, but
  2500 users are encouraged to use the new package.
  2501 
  2502 * Method "lexicographic_order" automatically synthesizes termination
  2503 relations as lexicographic combinations of size measures. 
  2504 
  2505 * Case-expressions allow arbitrary constructor-patterns (including
  2506 "_") and take their order into account, like in functional
  2507 programming.  Internally, this is translated into nested
  2508 case-expressions; missing cases are added and mapped to the predefined
  2509 constant "undefined". In complicated cases printing may no longer show
  2510 the original input but the internal form. Lambda-abstractions allow
  2511 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2512 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2513 variable.
  2514 
  2515 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2516 is an abbreviation for "of_nat :: nat => int". The simplification
  2517 rules for "of_nat" have been changed to work like "int" did
  2518 previously.  Potential INCOMPATIBILITY:
  2519   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2520   - of_nat_diff and of_nat_mult are no longer default simp rules
  2521 
  2522 * Method "algebra" solves polynomial equations over (semi)rings using
  2523 Groebner bases. The (semi)ring structure is defined by locales and the
  2524 tool setup depends on that generic context. Installing the method for
  2525 a specific type involves instantiating the locale and possibly adding
  2526 declarations for computation on the coefficients.  The method is
  2527 already instantiated for natural numbers and for the axiomatic class
  2528 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2529 CALCULEMUS 2007 for the general principles underlying this
  2530 architecture of context-aware proof-tools.
  2531 
  2532 * Method "ferrack" implements quantifier elimination over
  2533 special-purpose dense linear orders using locales (analogous to
  2534 "algebra"). The method is already installed for class
  2535 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2536 rat, etc.
  2537 
  2538 * Former constant "List.op @" now named "List.append".  Use ML
  2539 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2540 circumvent possible incompatibilities when working on ML level.
  2541 
  2542 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2543 
  2544 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2545 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2546 
  2547 * New syntax for Haskell-like list comprehension (input only), eg.
  2548 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2549 
  2550 * The special syntax for function "filter" has changed from [x :
  2551 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2552 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2553 
  2554 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2555 defined on nat only, as an abbreviation for [a..<Suc b]
  2556 INCOMPATIBILITY.
  2557 
  2558 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2559 
  2560 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2561 
  2562 * New lemma collection field_simps (an extension of ring_simps) for
  2563 manipulating (in)equations involving division. Multiplies with all
  2564 denominators that can be proved to be non-zero (in equations) or
  2565 positive/negative (in inequations).
  2566 
  2567 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2568 have been improved and renamed to ring_simps, group_simps and
  2569 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2570 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2571 
  2572 * Theory Library/Commutative_Ring: switched from recdef to function
  2573 package; constants add, mul, pow now curried.  Infix syntax for
  2574 algebraic operations.
  2575 
  2576 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2577 INCOMPATIBILITY.
  2578 
  2579 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2580 INCOMPATIBILITY.
  2581 
  2582 * HOL/records: generalised field-update to take a function on the
  2583 field rather than the new value: r(|A := x|) is translated to A_update
  2584 (K x) r The K-combinator that is internally used is called K_record.
  2585 INCOMPATIBILITY: Usage of the plain update functions has to be
  2586 adapted.
  2587  
  2588 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2589 * x = 0, which are required for a semiring.  Richer structures do not
  2590 inherit from semiring_0 anymore, because this property is a theorem
  2591 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2592 there is more to prove, but this is mostly trivial.
  2593 
  2594 * Class "recpower" is generalized to arbitrary monoids, not just
  2595 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2596 commutativity or semiring properties additionally.
  2597 
  2598 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2599 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2600 better use 'abbreviation'.
  2601 
  2602 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2603 
  2604 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2605 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2606 significant changes for setting up numeral syntax for types:
  2607   - New constants Numeral.pred and Numeral.succ instead
  2608       of former Numeral.bin_pred and Numeral.bin_succ.
  2609   - Use integer operations instead of bin_add, bin_mult and so on.
  2610   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2611   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2612 
  2613 See src/HOL/Integ/IntArith.thy for an example setup.
  2614 
  2615 * Command 'normal_form' computes the normal form of a term that may
  2616 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2617 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2618 heavy-duty computations because the functions are compiled to ML
  2619 first.  Correspondingly, a method "normalization" is provided.  See
  2620 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2621 
  2622 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2623 25 like -->); output depends on the "iff" print_mode, the default is
  2624 "A = B" (with priority 50).
  2625 
  2626 * Relations less (<) and less_eq (<=) are also available on type bool.
  2627 Modified syntax to disallow nesting without explicit parentheses,
  2628 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2629 INCOMPATIBILITY.
  2630 
  2631 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2632 
  2633 * Relation composition operator "op O" now has precedence 75 and binds
  2634 stronger than union and intersection. INCOMPATIBILITY.
  2635 
  2636 * The old set interval syntax "{m..n(}" (and relatives) has been
  2637 removed.  Use "{m..<n}" (and relatives) instead.
  2638 
  2639 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2640 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2641 ``declare [[simproc del: neq]]''.
  2642 
  2643 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2644 True/False.
  2645 
  2646 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2647 
  2648 * Theorem setsum_mult renamed to setsum_right_distrib.
  2649 
  2650 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2651 ``rule'' method.
  2652 
  2653 * Reimplemented methods "sat" and "satx", with several improvements:
  2654 goals no longer need to be stated as "<prems> ==> False", equivalences
  2655 (i.e. "=" on type bool) are handled, variable names of the form
  2656 "lit_<n>" are no longer reserved, significant speedup.
  2657 
  2658 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2659 zChaff is still supported as well.
  2660 
  2661 * 'inductive' and 'datatype': provide projections of mutual rules,
  2662 bundled as foo_bar.inducts;
  2663 
  2664 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2665 Library.
  2666 
  2667 * Library: moved theory Accessible_Part to main HOL.
  2668 
  2669 * Library: added theory Coinductive_List of potentially infinite lists
  2670 as greatest fixed-point.
  2671 
  2672 * Library: added theory AssocList which implements (finite) maps as
  2673 association lists.
  2674 
  2675 * Method "evaluation" solves goals (i.e. a boolean expression)
  2676 efficiently by compiling it to ML.  The goal is "proved" (via an
  2677 oracle) if it evaluates to True.
  2678 
  2679 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2680 also when invoked by the simplifier.  This results in the Simplifier
  2681 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2682 Configuration option fast_arith_split_limit=0 recovers the old
  2683 behavior.
  2684 
  2685 * Support for hex (0x20) and binary (0b1001) numerals.
  2686 
  2687 * New method: reify eqs (t), where eqs are equations for an
  2688 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2689 parameter, computes a term s::'b and a list xs::'a list and proves the
  2690 theorem I xs s = t. This is also known as reification or quoting. The
  2691 resulting theorem is applied to the subgoal to substitute t with I xs
  2692 s.  If t is omitted, the subgoal itself is reified.
  2693 
  2694 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2695 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2696 where f is supposed to be a computable function (in the sense of code
  2697 generattion). The method uses reify to compute s and xs as above then
  2698 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2699 r and finally gets the theorem t = r, which is again applied to the
  2700 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2701 
  2702 * Reflection: Automatic reification now handels binding, an example is
  2703 available in src/HOL/ex/ReflectionEx.thy
  2704 
  2705 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2706 command 'statespace' that is similar to 'record', but introduces an
  2707 abstract specification based on the locale infrastructure instead of
  2708 HOL types.  This leads to extra flexibility in composing state spaces,
  2709 in particular multiple inheritance and renaming of components.
  2710 
  2711 
  2712 *** HOL-Complex ***
  2713 
  2714 * Hyperreal: Functions root and sqrt are now defined on negative real
  2715 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2716 Nonnegativity side conditions have been removed from many lemmas, so
  2717 that more subgoals may now be solved by simplification; potential
  2718 INCOMPATIBILITY.
  2719 
  2720 * Real: new type classes formalize real normed vector spaces and
  2721 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2722 and norm :: 'a => real.
  2723 
  2724 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2725 reals into other types. The overloaded constant Reals :: 'a set is now
  2726 defined as range of_real; potential INCOMPATIBILITY.
  2727 
  2728 * Real: proper support for ML code generation, including 'quickcheck'.
  2729 Reals are implemented as arbitrary precision rationals.
  2730 
  2731 * Hyperreal: Several constants that previously worked only for the
  2732 reals have been generalized, so they now work over arbitrary vector
  2733 spaces. Type annotations may need to be added in some cases; potential
  2734 INCOMPATIBILITY.
  2735 
  2736   Infinitesimal  :: ('a::real_normed_vector) star set
  2737   HFinite        :: ('a::real_normed_vector) star set
  2738   HInfinite      :: ('a::real_normed_vector) star set
  2739   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2740   monad          :: ('a::real_normed_vector) star => 'a star set
  2741   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2742   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2743   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2744   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2745   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2746   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2747   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2748   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2749   sgn            :: 'a::real_normed_vector => 'a
  2750   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2751 
  2752 * Complex: Some complex-specific constants are now abbreviations for
  2753 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2754 hnorm.  Other constants have been entirely removed in favor of the
  2755 polymorphic versions (INCOMPATIBILITY):
  2756 
  2757   approx        <-- capprox
  2758   HFinite       <-- CFinite
  2759   HInfinite     <-- CInfinite
  2760   Infinitesimal <-- CInfinitesimal
  2761   monad         <-- cmonad
  2762   galaxy        <-- cgalaxy
  2763   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2764   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2765   (ns)deriv     <-- (ns)cderiv
  2766 
  2767 
  2768 *** HOL-Algebra ***
  2769 
  2770 * Formalisation of ideals and the quotient construction over rings.
  2771 
  2772 * Order and lattice theory no longer based on records.
  2773 INCOMPATIBILITY.
  2774 
  2775 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2776 greatest_closed.  INCOMPATIBILITY.
  2777 
  2778 * Method algebra is now set up via an attribute.  For examples see
  2779 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2780 of algebraic structures.
  2781 
  2782 * Renamed theory CRing to Ring.
  2783 
  2784 
  2785 *** HOL-Nominal ***
  2786 
  2787 * Substantial, yet incomplete support for nominal datatypes (binding
  2788 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2789 src/HOL/Nominal/Examples.  Prospective users should consult
  2790 http://isabelle.in.tum.de/nominal/
  2791 
  2792 
  2793 *** ML ***
  2794 
  2795 * ML basics: just one true type int, which coincides with IntInf.int
  2796 (even on SML/NJ).
  2797 
  2798 * ML within Isar: antiquotations allow to embed statically-checked
  2799 formal entities in the source, referring to the context available at
  2800 compile-time.  For example:
  2801 
  2802 ML {* @{sort "{zero,one}"} *}
  2803 ML {* @{typ "'a => 'b"} *}
  2804 ML {* @{term "%x. x"} *}
  2805 ML {* @{prop "x == y"} *}
  2806 ML {* @{ctyp "'a => 'b"} *}
  2807 ML {* @{cterm "%x. x"} *}
  2808 ML {* @{cprop "x == y"} *}
  2809 ML {* @{thm asm_rl} *}
  2810 ML {* @{thms asm_rl} *}
  2811 ML {* @{type_name c} *}
  2812 ML {* @{type_syntax c} *}
  2813 ML {* @{const_name c} *}
  2814 ML {* @{const_syntax c} *}
  2815 ML {* @{context} *}
  2816 ML {* @{theory} *}
  2817 ML {* @{theory Pure} *}
  2818 ML {* @{theory_ref} *}
  2819 ML {* @{theory_ref Pure} *}
  2820 ML {* @{simpset} *}
  2821 ML {* @{claset} *}
  2822 ML {* @{clasimpset} *}
  2823 
  2824 The same works for sources being ``used'' within an Isar context.
  2825 
  2826 * ML in Isar: improved error reporting; extra verbosity with
  2827 ML_Context.trace enabled.
  2828 
  2829 * Pure/General/table.ML: the join operations now works via exceptions
  2830 DUP/SAME instead of type option. This is simpler in simple cases, and
  2831 admits slightly more efficient complex applications.
  2832 
  2833 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2834 use Context.generic instead of just theory.
  2835 
  2836 * Pure: datatype Context.generic joins theory/Proof.context and
  2837 provides some facilities for code that works in either kind of
  2838 context, notably GenericDataFun for uniform theory and proof data.
  2839 
  2840 * Pure: simplified internal attribute type, which is now always
  2841 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2842 local (Proof.context) attributes have been discontinued, while
  2843 minimizing code duplication. Thm.rule_attribute and
  2844 Thm.declaration_attribute build canonical attributes; see also structure
  2845 Context for further operations on Context.generic, notably
  2846 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2847 declarations and definitions.
  2848 
  2849 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2850 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2851 init only required for impure data. INCOMPATIBILITY: empty really need
  2852 to be empty (no dependencies on theory content!)
  2853 
  2854 * Pure/kernel: consts certification ignores sort constraints given in
  2855 signature declarations. (This information is not relevant to the
  2856 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2857 potential INCOMPATIBILITY.
  2858 
  2859 * Pure: axiomatic type classes are now purely definitional, with
  2860 explicit proofs of class axioms and super class relations performed
  2861 internally. See Pure/axclass.ML for the main internal interfaces --
  2862 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2863 AxClass.axiomatize_class/classrel/arity supersede
  2864 Sign.add_classes/classrel/arities.
  2865 
  2866 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2867 global/local versions on theory vs. Proof.context have been
  2868 discontinued; Attrib.syntax and Method.syntax have been adapted
  2869 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2870 attributes, methods, etc.
  2871 
  2872 * Pure: several functions of signature "... -> theory -> theory * ..."
  2873 have been reoriented to "... -> theory -> ... * theory" in order to
  2874 allow natural usage in combination with the ||>, ||>>, |-> and
  2875 fold_map combinators.
  2876 
  2877 * Pure: official theorem names (closed derivations) and additional
  2878 comments (tags) are now strictly separate.  Name hints -- which are
  2879 maintained as tags -- may be attached any time without affecting the
  2880 derivation.
  2881 
  2882 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2883 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2884 achieve the old behaviour.
  2885 
  2886 * Pure: the "Goal" constant is now called "prop", supporting a
  2887 slightly more general idea of ``protecting'' meta-level rule
  2888 statements.
  2889 
  2890 * Pure: Logic.(un)varify only works in a global context, which is now
  2891 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2892 Logic.legacy_(un)varify as temporary workaround.
  2893 
  2894 * Pure: structure Name provides scalable operations for generating
  2895 internal variable names, notably Name.variants etc.  This replaces
  2896 some popular functions from term.ML:
  2897 
  2898   Term.variant		->  Name.variant
  2899   Term.variantlist	->  Name.variant_list
  2900   Term.invent_names	->  Name.invent_list
  2901 
  2902 Note that low-level renaming rarely occurs in new code -- operations
  2903 from structure Variable are used instead (see below).
  2904 
  2905 * Pure: structure Variable provides fundamental operations for proper
  2906 treatment of fixed/schematic variables in a context.  For example,
  2907 Variable.import introduces fixes for schematics of given facts and
  2908 Variable.export reverses the effect (up to renaming) -- this replaces
  2909 various freeze_thaw operations.
  2910 
  2911 * Pure: structure Goal provides simple interfaces for
  2912 init/conclude/finish and tactical prove operations (replacing former
  2913 Tactic.prove).  Goal.prove is the canonical way to prove results
  2914 within a given context; Goal.prove_global is a degraded version for
  2915 theory level goals, including a global Drule.standard.  Note that
  2916 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2917 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2918 in a locale context).
  2919 
  2920 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2921 and type checking (Syntax.check_term etc.), with common combinations
  2922 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2923 which are considered legacy and await removal.
  2924 
  2925 * Pure/Syntax: generic interfaces for type unchecking
  2926 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2927 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2928 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2929 available for convenience, but refer to the very same operations using
  2930 a mere theory instead of a full context.
  2931 
  2932 * Isar: simplified treatment of user-level errors, using exception
  2933 ERROR of string uniformly.  Function error now merely raises ERROR,
  2934 without any side effect on output channels.  The Isar toplevel takes
  2935 care of proper display of ERROR exceptions.  ML code may use plain
  2936 handle/can/try; cat_error may be used to concatenate errors like this:
  2937 
  2938   ... handle ERROR msg => cat_error msg "..."
  2939 
  2940 Toplevel ML code (run directly or through the Isar toplevel) may be
  2941 embedded into the Isar toplevel with exception display/debug like
  2942 this:
  2943 
  2944   Isar.toplevel (fn () => ...)
  2945 
  2946 INCOMPATIBILITY, removed special transform_error facilities, removed
  2947 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2948 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2949 -- use plain ERROR instead.
  2950 
  2951 * Isar: theory setup now has type (theory -> theory), instead of a
  2952 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2953 
  2954 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2955 ProofContext.debug/verbose flags.
  2956 
  2957 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2958 theory before entering a proof state.  Transactions now always see a
  2959 quasi-functional intermediate checkpoint, both in interactive and
  2960 batch mode.
  2961 
  2962 * Isar: simplified interfaces for outer syntax.  Renamed
  2963 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2964 OuterSyntax.add_parsers -- this functionality is now included in
  2965 OuterSyntax.command etc.  INCOMPATIBILITY.
  2966 
  2967 * Simplifier: the simpset of a running simplification process now
  2968 contains a proof context (cf. Simplifier.the_context), which is the
  2969 very context that the initial simpset has been retrieved from (by
  2970 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2971 (solver, looper etc.) may depend on arbitrary proof data.
  2972 
  2973 * Simplifier.inherit_context inherits the proof context (plus the
  2974 local bounds) of the current simplification process; any simproc
  2975 etc. that calls the Simplifier recursively should do this!  Removed
  2976 former Simplifier.inherit_bounds, which is already included here --
  2977 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2978 specify an explicit context using Simplifier.context/theory_context.
  2979 
  2980 * Simplifier/Classical Reasoner: more abstract interfaces
  2981 change_simpset/claset for modifying the simpset/claset reference of a
  2982 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2983 INCOMPATIBILITY.
  2984 
  2985 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2986 "Trueprop" etc.
  2987 
  2988 
  2989 *** System ***
  2990 
  2991 * settings: the default heap location within ISABELLE_HOME_USER now
  2992 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2993 Isabelle installations.
  2994 
  2995 * isabelle-process: option -S (secure mode) disables some critical
  2996 operations, notably runtime compilation and evaluation of ML source
  2997 code.
  2998 
  2999 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3000 
  3001 * Support for parallel execution, using native multicore support of
  3002 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3003 independent theories, according to the given theory header
  3004 specifications. The maximum number of worker threads is specified via
  3005 usedir option -M or the "max-threads" setting in Proof General. A
  3006 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3007 to 6 on a 8-core machine.  User-code needs to observe certain
  3008 guidelines for thread-safe programming, see appendix A in the Isar
  3009 Implementation manual.
  3010 
  3011 
  3012 
  3013 New in Isabelle2005 (October 2005)
  3014 ----------------------------------
  3015 
  3016 *** General ***
  3017 
  3018 * Theory headers: the new header syntax for Isar theories is
  3019 
  3020   theory <name>
  3021   imports <theory1> ... <theoryN>
  3022   uses <file1> ... <fileM>
  3023   begin
  3024 
  3025 where the 'uses' part is optional.  The previous syntax
  3026 
  3027   theory <name> = <theory1> + ... + <theoryN>:
  3028 
  3029 will disappear in the next release.  Use isatool fixheaders to convert
  3030 existing theory files.  Note that there is no change in ancient
  3031 non-Isar theories now, but these will disappear soon.
  3032 
  3033 * Theory loader: parent theories can now also be referred to via
  3034 relative and absolute paths.
  3035 
  3036 * Command 'find_theorems' searches for a list of criteria instead of a
  3037 list of constants. Known criteria are: intro, elim, dest, name:string,
  3038 simp:term, and any term. Criteria can be preceded by '-' to select
  3039 theorems that do not match. Intro, elim, dest select theorems that
  3040 match the current goal, name:s selects theorems whose fully qualified
  3041 name contain s, and simp:term selects all simplification rules whose
  3042 lhs match term.  Any other term is interpreted as pattern and selects
  3043 all theorems matching the pattern. Available in ProofGeneral under
  3044 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3045 
  3046   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3047 
  3048 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3049 matching the current goal as introduction rule and not having "HOL."
  3050 in their name (i.e. not being defined in theory HOL).
  3051 
  3052 * Command 'thms_containing' has been discontinued in favour of
  3053 'find_theorems'; INCOMPATIBILITY.
  3054 
  3055 * Communication with Proof General is now 8bit clean, which means that
  3056 Unicode text in UTF-8 encoding may be used within theory texts (both
  3057 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3058 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3059 
  3060   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3061   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3062 
  3063 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3064 Classical Reasoner.  Typical big applications run around 2 times
  3065 faster.
  3066 
  3067 
  3068 *** Document preparation ***
  3069 
  3070 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3071 of raw sources.  Only those symbols that do not require additional
  3072 LaTeX packages (depending on comments in isabellesym.sty) are
  3073 displayed properly, everything else is left verbatim.  isatool display
  3074 and isatool print are used as front ends (these are subject to the
  3075 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3076 
  3077 * Command tags control specific markup of certain regions of text,
  3078 notably folding and hiding.  Predefined tags include "theory" (for
  3079 theory begin and end), "proof" for proof commands, and "ML" for
  3080 commands involving ML code; the additional tags "visible" and
  3081 "invisible" are unused by default.  Users may give explicit tag
  3082 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3083 interpretation of tags is determined by the LaTeX job during document
  3084 preparation: see option -V of isatool usedir, or options -n and -t of
  3085 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3086 \isadroptag.
  3087 
  3088 Several document versions may be produced at the same time via isatool
  3089 usedir (the generated index.html will link all of them).  Typical
  3090 specifications include ''-V document=theory,proof,ML'' to present
  3091 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3092 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3093 these parts without any formal replacement text.  The Isabelle site
  3094 default settings produce ''document'' and ''outline'' versions as
  3095 specified above.
  3096 
  3097 * Several new antiquotations:
  3098 
  3099   @{term_type term} prints a term with its type annotated;
  3100 
  3101   @{typeof term} prints the type of a term;
  3102 
  3103   @{const const} is the same as @{term const}, but checks that the
  3104   argument is a known logical constant;
  3105 
  3106   @{term_style style term} and @{thm_style style thm} print a term or
  3107   theorem applying a "style" to it
  3108 
  3109   @{ML text}
  3110 
  3111 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3112 definitions, equations, inequations etc., 'concl' printing only the
  3113 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3114 to print the specified premise.  TermStyle.add_style provides an ML
  3115 interface for introducing further styles.  See also the "LaTeX Sugar"
  3116 document practical applications.  The ML antiquotation prints
  3117 type-checked ML expressions verbatim.
  3118 
  3119 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3120 and 'text' support optional locale specification '(in loc)', which
  3121 specifies the default context for interpreting antiquotations.  For
  3122 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3123 
  3124 * Option 'locale=NAME' of antiquotations specifies an alternative
  3125 context interpreting the subsequent argument.  For example: @{thm
  3126 [locale=lattice] inf_assoc}.
  3127 
  3128 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3129 a proof context.
  3130 
  3131 * Proper output of antiquotations for theory commands involving a
  3132 proof context (such as 'locale' or 'theorem (in loc) ...').
  3133 
  3134 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3135 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3136 
  3137 * isatool usedir: new option -C (default true) controls whether option
  3138 -D should include a copy of the original document directory; -C false
  3139 prevents unwanted effects such as copying of administrative CVS data.
  3140 
  3141 
  3142 *** Pure ***
  3143 
  3144 * Considerably improved version of 'constdefs' command.  Now performs
  3145 automatic type-inference of declared constants; additional support for
  3146 local structure declarations (cf. locales and HOL records), see also
  3147 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3148 sequential dependencies of definitions within a single 'constdefs'
  3149 section; moreover, the declared name needs to be an identifier.  If
  3150 all fails, consider to fall back on 'consts' and 'defs' separately.
  3151 
  3152 * Improved indexed syntax and implicit structures.  First of all,
  3153 indexed syntax provides a notational device for subscripted
  3154 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3155 expressions.  Secondly, in a local context with structure
  3156 declarations, number indexes \<^sub>n or the empty index (default
  3157 number 1) refer to a certain fixed variable implicitly; option
  3158 show_structs controls printing of implicit structures.  Typical
  3159 applications of these concepts involve record types and locales.
  3160 
  3161 * New command 'no_syntax' removes grammar declarations (and
  3162 translations) resulting from the given syntax specification, which is
  3163 interpreted in the same manner as for the 'syntax' command.
  3164 
  3165 * 'Advanced' translation functions (parse_translation etc.) may depend
  3166 on the signature of the theory context being presently used for
  3167 parsing/printing, see also isar-ref manual.
  3168 
  3169 * Improved 'oracle' command provides a type-safe interface to turn an
  3170 ML expression of type theory -> T -> term into a primitive rule of
  3171 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3172 is already included here); see also FOL/ex/IffExample.thy;
  3173 INCOMPATIBILITY.
  3174 
  3175 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3176 before); "cI" is no longer bound, use "c.intro" instead.
  3177 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3178 axclasses vs. locales.
  3179 
  3180 * Improved internal renaming of symbolic identifiers -- attach primes
  3181 instead of base 26 numbers.
  3182 
  3183 * New flag show_question_marks controls printing of leading question
  3184 marks in schematic variable names.
  3185 
  3186 * In schematic variable names, *any* symbol following \<^isub> or
  3187 \<^isup> is now treated as part of the base name.  For example, the
  3188 following works without printing of awkward ".0" indexes:
  3189 
  3190   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3191     by simp
  3192 
  3193 * Inner syntax includes (*(*nested*) comments*).
  3194 
  3195 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3196 annotations as "(00...)".
  3197 
  3198 * Clear separation of logical types and nonterminals, where the latter
  3199 may only occur in 'syntax' specifications or type abbreviations.
  3200 Before that distinction was only partially implemented via type class
  3201 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3202 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3203 exotic syntax specifications may require further adaption
  3204 (e.g. Cube/Cube.thy).
  3205 
  3206 * Removed obsolete type class "logic", use the top sort {} instead.
  3207 Note that non-logical types should be declared as 'nonterminals'
  3208 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3209 specifications.
  3210 
  3211 * Attributes 'induct' and 'cases': type or set names may now be
  3212 locally fixed variables as well.
  3213 
  3214 * Simplifier: can now control the depth to which conditional rewriting
  3215 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3216 Limit.
  3217 
  3218 * Simplifier: simplification procedures may now take the current
  3219 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3220 interface), which is very useful for calling the Simplifier
  3221 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3222 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3223 low-level mk_simproc no longer applies Logic.varify internally, to
  3224 allow for use in a context of fixed variables.
  3225 
  3226 * thin_tac now works even if the assumption being deleted contains !!
  3227 or ==>.  More generally, erule now works even if the major premise of
  3228 the elimination rule contains !! or ==>.
  3229 
  3230 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3231 
  3232 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3233 from Pure, which contains all common declarations already.  Both
  3234 theories are defined via plain Isabelle/Isar .thy files.
  3235 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3236 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3237 use isatool fixcpure to adapt your theory and ML sources.
  3238 
  3239 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3240 selections of theorems in named facts via index ranges.
  3241 
  3242 * 'print_theorems': in theory mode, really print the difference
  3243 wrt. the last state (works for interactive theory development only),
  3244 in proof mode print all local facts (cf. 'print_facts');
  3245 
  3246 * 'hide': option '(open)' hides only base names.
  3247 
  3248 * More efficient treatment of intermediate checkpoints in interactive
  3249 theory development.
  3250 
  3251 * Code generator is now invoked via code_module (incremental code
  3252 generation) and code_library (modular code generation, ML structures
  3253 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3254 must be quoted when used as identifiers.
  3255 
  3256 * New 'value' command for reading, evaluating and printing terms using
  3257 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3258 quoted when used as identifier.
  3259 
  3260 
  3261 *** Locales ***
  3262 
  3263 * New commands for the interpretation of locale expressions in
  3264 theories (1), locales (2) and proof contexts (3).  These generate
  3265 proof obligations from the expression specification.  After the
  3266 obligations have been discharged, theorems of the expression are added
  3267 to the theory, target locale or proof context.  The synopsis of the
  3268 commands is a follows:
  3269 
  3270   (1) interpretation expr inst
  3271   (2) interpretation target < expr
  3272   (3) interpret expr inst
  3273 
  3274 Interpretation in theories and proof contexts require a parameter
  3275 instantiation of terms from the current context.  This is applied to
  3276 specifications and theorems of the interpreted expression.
  3277 Interpretation in locales only permits parameter renaming through the
  3278 locale expression.  Interpretation is smart in that interpretations
  3279 that are active already do not occur in proof obligations, neither are
  3280 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3281 inspect active interpretations of a particular locale.  For details,
  3282 see the Isar Reference manual.  Examples can be found in
  3283 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3284 
  3285 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3286 'interpret' instead.
  3287 
  3288 * New context element 'constrains' for adding type constraints to
  3289 parameters.
  3290 
  3291 * Context expressions: renaming of parameters with syntax
  3292 redeclaration.
  3293 
  3294 * Locale declaration: 'includes' disallowed.
  3295 
  3296 * Proper static binding of attribute syntax -- i.e. types / terms /
  3297 facts mentioned as arguments are always those of the locale definition
  3298 context, independently of the context of later invocations.  Moreover,
  3299 locale operations (renaming and type / term instantiation) are applied
  3300 to attribute arguments as expected.
  3301 
  3302 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3303 actual attributes; rare situations may require Attrib.attribute to
  3304 embed those attributes into Attrib.src that lack concrete syntax.
  3305 Attribute implementations need to cooperate properly with the static
  3306 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3307 Attrib.XXX_thm etc. already do the right thing without further
  3308 intervention.  Only unusual applications -- such as "where" or "of"
  3309 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3310 on the context and the facts involved -- may have to assign parsed
  3311 values to argument tokens explicitly.
  3312 
  3313 * Changed parameter management in theorem generation for long goal
  3314 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3315 theorem statement in rare situations.
  3316 
  3317 * Locale inspection command 'print_locale' omits notes elements.  Use
  3318 'print_locale!' to have them included in the output.
  3319 
  3320 
  3321 *** Provers ***
  3322 
  3323 * Provers/hypsubst.ML: improved version of the subst method, for
  3324 single-step rewriting: it now works in bound variable contexts. New is
  3325 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3326 rewrite a different subterm than the original subst method, which is
  3327 still available as 'simplesubst'.
  3328 
  3329 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3330 and quasi orders.
  3331 
  3332 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3333 reflexive-transitive closure of relations.
  3334 
  3335 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3336 limit (previously hard-coded with a value of 20) user-definable.
  3337 
  3338 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3339 is peformed already.  Object-logics merely need to finish their
  3340 initial simpset configuration as before.  INCOMPATIBILITY.
  3341 
  3342 
  3343 *** HOL ***
  3344 
  3345 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3346 
  3347   syntax (epsilon)
  3348     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3349 
  3350 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3351 and x-symbol; use option '-m epsilon' to get it actually printed.
  3352 Moreover, the mathematically important symbolic identifier \<epsilon>
  3353 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3354 
  3355 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3356 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3357 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3358 support corresponding Isar calculations.
  3359 
  3360 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3361 instead of ":".
  3362 
  3363 * theory SetInterval: changed the syntax for open intervals:
  3364 
  3365   Old       New
  3366   {..n(}    {..<n}
  3367   {)n..}    {n<..}
  3368   {m..n(}   {m..<n}
  3369   {)m..n}   {m<..n}
  3370   {)m..n(}  {m<..<n}
  3371 
  3372 The old syntax is still supported but will disappear in the next
  3373 release.  For conversion use the following Emacs search and replace
  3374 patterns (these are not perfect but work quite well):
  3375 
  3376   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3377   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3378 
  3379 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3380 equalities in commutative rings; method 'algebra' provides a generic
  3381 interface.
  3382 
  3383 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3384 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3385 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3386 be a tuple pattern.
  3387 
  3388 Some new syntax forms are available:
  3389 
  3390   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3391   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3392   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3393   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3394 
  3395 The latter form "\<Sum>x < k. e" used to be based on a separate
  3396 function "Summation", which has been discontinued.
  3397 
  3398 * theory Finite_Set: in structured induction proofs, the insert case
  3399 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3400 (insert F x)'.
  3401 
  3402 * The 'refute' command has been extended to support a much larger
  3403 fragment of HOL, including axiomatic type classes, constdefs and
  3404 typedefs, inductive datatypes and recursion.
  3405 
  3406 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3407 Requires zChaff with proof generation to be installed.  See
  3408 HOL/ex/SAT_Examples.thy for examples.
  3409 
  3410 * Datatype induction via method 'induct' now preserves the name of the
  3411 induction variable. For example, when proving P(xs::'a list) by
  3412 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3413 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3414 in unstructured proof scripts.
  3415 
  3416 * Reworked implementation of records.  Improved scalability for
  3417 records with many fields, avoiding performance problems for type
  3418 inference. Records are no longer composed of nested field types, but
  3419 of nested extension types. Therefore the record type only grows linear
  3420 in the number of extensions and not in the number of fields.  The
  3421 top-level (users) view on records is preserved.  Potential
  3422 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3423 old record representation. The type generated for a record is called
  3424 <record_name>_ext_type.
  3425 
  3426 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3427 proofs triggered by a record definition or a simproc (if
  3428 quick_and_dirty is enabled).  Definitions of large records can take
  3429 quite long.
  3430 
  3431 New simproc record_upd_simproc for simplification of multiple record
  3432 updates enabled by default.  Moreover, trivial updates are also
  3433 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3434 occasionally, since simplification is more powerful by default.
  3435 
  3436 * typedef: proper support for polymorphic sets, which contain extra
  3437 type-variables in the term.
  3438 
  3439 * Simplifier: automatically reasons about transitivity chains
  3440 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3441 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3442 old proofs break occasionally as simplification may now solve more
  3443 goals than previously.
  3444 
  3445 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3446 present.  Works for all partial orders (class "order"), in particular
  3447 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3448 just like y <= x.
  3449 
  3450 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3451 bound variable or a constant then the let is unfolded.  Otherwise
  3452 first a is simplified to b, and then f b is simplified to g. If
  3453 possible we abstract b from g arriving at "let x = b in h x",
  3454 otherwise we unfold the let and arrive at g.  The simproc can be
  3455 enabled/disabled by the reference use_let_simproc.  Potential
  3456 INCOMPATIBILITY since simplification is more powerful by default.
  3457 
  3458 * Classical reasoning: the meson method now accepts theorems as arguments.
  3459 
  3460 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3461 jobs to provide advice on the provability of subgoals.
  3462 
  3463 * Theory OrderedGroup and Ring_and_Field: various additions and
  3464 improvements to faciliate calculations involving equalities and
  3465 inequalities.
  3466 
  3467 The following theorems have been eliminated or modified
  3468 (INCOMPATIBILITY):
  3469 
  3470   abs_eq             now named abs_of_nonneg
  3471   abs_of_ge_0        now named abs_of_nonneg
  3472   abs_minus_eq       now named abs_of_nonpos
  3473   imp_abs_id         now named abs_of_nonneg
  3474   imp_abs_neg_id     now named abs_of_nonpos
  3475   mult_pos           now named mult_pos_pos
  3476   mult_pos_le        now named mult_nonneg_nonneg
  3477   mult_pos_neg_le    now named mult_nonneg_nonpos
  3478   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3479   mult_neg           now named mult_neg_neg
  3480   mult_neg_le        now named mult_nonpos_nonpos
  3481 
  3482 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3483      
  3484      zero_le_square
  3485      not_square_less_zero 
  3486 
  3487   The following lemmas have been deleted from Real/RealPow:
  3488   
  3489      realpow_zero_zero
  3490      realpow_two
  3491      realpow_less
  3492      zero_le_power
  3493      realpow_two_le
  3494      abs_realpow_two
  3495      realpow_two_abs     
  3496 
  3497 * Theory Parity: added rules for simplifying exponents.
  3498 
  3499 * Theory List:
  3500 
  3501 The following theorems have been eliminated or modified
  3502 (INCOMPATIBILITY):
  3503 
  3504   list_all_Nil       now named list_all.simps(1)
  3505   list_all_Cons      now named list_all.simps(2)
  3506   list_all_conv      now named list_all_iff
  3507   set_mem_eq         now named mem_iff
  3508 
  3509 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3510 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3511 
  3512 
  3513 *** HOL-Complex ***
  3514 
  3515 * Theory RealDef: better support for embedding natural numbers and
  3516 integers in the reals.
  3517 
  3518 The following theorems have been eliminated or modified
  3519 (INCOMPATIBILITY):
  3520 
  3521   exp_ge_add_one_self  now requires no hypotheses
  3522   real_of_int_add      reversed direction of equality (use [symmetric])
  3523   real_of_int_minus    reversed direction of equality (use [symmetric])
  3524   real_of_int_diff     reversed direction of equality (use [symmetric])
  3525   real_of_int_mult     reversed direction of equality (use [symmetric])
  3526 
  3527 * Theory RComplete: expanded support for floor and ceiling functions.
  3528 
  3529 * Theory Ln is new, with properties of the natural logarithm
  3530 
  3531 * Hyperreal: There is a new type constructor "star" for making
  3532 nonstandard types.  The old type names are now type synonyms:
  3533 
  3534   hypreal = real star
  3535   hypnat = nat star
  3536   hcomplex = complex star
  3537 
  3538 * Hyperreal: Many groups of similarly-defined constants have been
  3539 replaced by polymorphic versions (INCOMPATIBILITY):
  3540 
  3541   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3542 
  3543   starset      <-- starsetNat, starsetC
  3544   *s*          <-- *sNat*, *sc*
  3545   starset_n    <-- starsetNat_n, starsetC_n
  3546   *sn*         <-- *sNatn*, *scn*
  3547   InternalSets <-- InternalNatSets, InternalCSets
  3548 
  3549   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3550   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3551   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3552   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3553   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3554 
  3555 * Hyperreal: Many type-specific theorems have been removed in favor of
  3556 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3557 
  3558   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3559   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3560   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3561   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3562   right_minus <-- hypreal_add_minus
  3563   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3564   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3565   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3566   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3567   mult_1_right <-- hcomplex_mult_one_right
  3568   mult_zero_left <-- hcomplex_mult_zero_left
  3569   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3570   right_distrib <-- hypnat_add_mult_distrib2
  3571   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3572   right_inverse <-- hypreal_mult_inverse
  3573   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3574   order_refl <-- {hypreal,hypnat}_le_refl
  3575   order_trans <-- {hypreal,hypnat}_le_trans
  3576   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3577   order_less_le <-- {hypreal,hypnat}_less_le
  3578   linorder_linear <-- {hypreal,hypnat}_le_linear
  3579   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3580   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3581   add_nonneg_nonneg <-- hypreal_le_add_order
  3582 
  3583 * Hyperreal: Separate theorems having to do with type-specific
  3584 versions of constants have been merged into theorems that apply to the
  3585 new polymorphic constants (INCOMPATIBILITY):
  3586 
  3587   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3588   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3589   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3590   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3591   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3592   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3593   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3594   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3595   STAR_diff <-- {STAR,STARC}_diff
  3596   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3597     STARC_hcomplex_of_complex}_image_subset
  3598   starset_n_Un <-- starset{Nat,C}_n_Un
  3599   starset_n_Int <-- starset{Nat,C}_n_Int
  3600   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3601   starset_n_diff <-- starset{Nat,C}_n_diff
  3602   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3603   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3604   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3605   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3606   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3607   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3608   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3609   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3610   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3611   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3612   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3613   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3614   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3615   starfun_diff <-- starfun{C,RC,CR}_diff
  3616   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3617   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3618   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3619   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3620   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3621   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3622   starfun_Id <-- starfunC_Id
  3623   starfun_approx <-- starfun{Nat,CR}_approx
  3624   starfun_capprox <-- starfun{C,RC}_capprox
  3625   starfun_abs <-- starfunNat_rabs
  3626   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3627   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3628   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3629   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3630   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3631   starfun_add_approx <-- starfunCR_add_approx
  3632   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3633   starfun_divide <-- starfun{C,CR,RC}_divide
  3634   starfun_n <-- starfun{Nat,C}_n
  3635   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3636   starfun_n_add <-- starfun{Nat,C}_n_add
  3637   starfun_n_add_minus <-- starfunNat_n_add_minus
  3638   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3639   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3640   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3641 
  3642   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3643   star_n_minus <-- {hypreal,hcomplex}_minus
  3644   star_n_diff <-- {hypreal,hcomplex}_diff
  3645   star_n_mult <-- {hypreal,hcomplex}_mult
  3646   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3647   star_n_le <-- {hypreal,hypnat}_le
  3648   star_n_less <-- {hypreal,hypnat}_less
  3649   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3650   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3651   star_n_abs <-- hypreal_hrabs
  3652   star_n_divide <-- hcomplex_divide
  3653 
  3654   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3655   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3656   star_of_diff <-- hypreal_of_real_diff
  3657   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3658   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3659   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3660   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3661   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3662   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3663   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3664   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3665   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3666   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3667   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3668   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3669   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3670   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3671   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3672   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3673   star_of_power <-- hypreal_of_real_power
  3674   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3675 
  3676 * Hyperreal: new method "transfer" that implements the transfer
  3677 principle of nonstandard analysis. With a subgoal that mentions
  3678 nonstandard types like "'a star", the command "apply transfer"
  3679 replaces it with an equivalent one that mentions only standard types.
  3680 To be successful, all free variables must have standard types; non-
  3681 standard variables must have explicit universal quantifiers.
  3682 
  3683 * Hyperreal: A theory of Taylor series.
  3684 
  3685 
  3686 *** HOLCF ***
  3687 
  3688 * Discontinued special version of 'constdefs' (which used to support
  3689 continuous functions) in favor of the general Pure one with full
  3690 type-inference.
  3691 
  3692 * New simplification procedure for solving continuity conditions; it
  3693 is much faster on terms with many nested lambda abstractions (cubic
  3694 instead of exponential time).
  3695 
  3696 * New syntax for domain package: selector names are now optional.
  3697 Parentheses should be omitted unless argument is lazy, for example:
  3698 
  3699   domain 'a stream = cons "'a" (lazy "'a stream")
  3700 
  3701 * New command 'fixrec' for defining recursive functions with pattern
  3702 matching; defining multiple functions with mutual recursion is also
  3703 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3704 sinr, or any data constructor defined by the domain package. The given
  3705 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3706 syntax and examples.
  3707 
  3708 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3709 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3710 but the proof obligation additionally includes an admissibility
  3711 requirement. The packages generate instances of class cpo or pcpo,
  3712 with continuity and strictness theorems for Rep and Abs.
  3713 
  3714 * HOLCF: Many theorems have been renamed according to a more standard naming
  3715 scheme (INCOMPATIBILITY):
  3716 
  3717   foo_inject:  "foo$x = foo$y ==> x = y"
  3718   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3719   foo_less:    "(foo$x << foo$y) = (x << y)"
  3720   foo_strict:  "foo$UU = UU"
  3721   foo_defined: "... ==> foo$x ~= UU"
  3722   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3723 
  3724 
  3725 *** ZF ***
  3726 
  3727 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3728 including the First Isomorphism Theorem (on quotienting by the kernel
  3729 of a homomorphism).
  3730 
  3731 * ZF/Simplifier: install second copy of type solver that actually
  3732 makes use of TC rules declared to Isar proof contexts (or locales);
  3733 the old version is still required for ML proof scripts.
  3734 
  3735 
  3736 *** Cube ***
  3737 
  3738 * Converted to Isar theory format; use locales instead of axiomatic
  3739 theories.
  3740 
  3741 
  3742 *** ML ***
  3743 
  3744 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3745 for ||>, ||>>, |>>,
  3746 
  3747 * Pure/library.ML no longer defines its own option datatype, but uses
  3748 that of the SML basis, which has constructors NONE and SOME instead of
  3749 None and Some, as well as exception Option.Option instead of OPTION.
  3750 The functions the, if_none, is_some, is_none have been adapted
  3751 accordingly, while Option.map replaces apsome.
  3752 
  3753 * Pure/library.ML: the exception LIST has been given up in favour of
  3754 the standard exceptions Empty and Subscript, as well as
  3755 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3756 superceded by the standard hd and tl functions etc.
  3757 
  3758 A number of basic list functions are no longer exported to the ML
  3759 toplevel, as they are variants of predefined functions.  The following
  3760 suggests how one can translate existing code:
  3761 
  3762     rev_append xs ys = List.revAppend (xs, ys)
  3763     nth_elem (i, xs) = List.nth (xs, i)
  3764     last_elem xs = List.last xs
  3765     flat xss = List.concat xss
  3766     seq fs = List.app fs
  3767     partition P xs = List.partition P xs
  3768     mapfilter f xs = List.mapPartial f xs
  3769 
  3770 * Pure/library.ML: several combinators for linear functional
  3771 transformations, notably reverse application and composition:
  3772 
  3773   x |> f                f #> g
  3774   (x, y) |-> f          f #-> g
  3775 
  3776 * Pure/library.ML: introduced/changed precedence of infix operators:
  3777 
  3778   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3779   infix 2 ?;
  3780   infix 3 o oo ooo oooo;
  3781   infix 4 ~~ upto downto;
  3782 
  3783 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3784 infix operators.
  3785 
  3786 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3787 fold_map support linear functional transformations and nesting.  For
  3788 example:
  3789 
  3790   fold f [x1, ..., xN] y =
  3791     y |> f x1 |> ... |> f xN
  3792 
  3793   (fold o fold) f [xs1, ..., xsN] y =
  3794     y |> fold f xs1 |> ... |> fold f xsN
  3795 
  3796   fold f [x1, ..., xN] =
  3797     f x1 #> ... #> f xN
  3798 
  3799   (fold o fold) f [xs1, ..., xsN] =
  3800     fold f xs1 #> ... #> fold f xsN
  3801 
  3802 * Pure/library.ML: the following selectors on type 'a option are
  3803 available:
  3804 
  3805   the:               'a option -> 'a  (*partial*)
  3806   these:             'a option -> 'a  where 'a = 'b list
  3807   the_default: 'a -> 'a option -> 'a
  3808   the_list:          'a option -> 'a list
  3809 
  3810 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3811 basic operations for association lists, following natural argument
  3812 order; moreover the explicit equality predicate passed here avoids
  3813 potentially expensive polymorphic runtime equality checks.
  3814 The old functions may be expressed as follows:
  3815 
  3816   assoc = uncurry (AList.lookup (op =))
  3817   assocs = these oo AList.lookup (op =)
  3818   overwrite = uncurry (AList.update (op =)) o swap
  3819 
  3820 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3821 
  3822   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3823   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3824 
  3825 replacing make_keylist and keyfilter (occassionally used)
  3826 Naive rewrites:
  3827 
  3828   make_keylist = AList.make
  3829   keyfilter = AList.find (op =)
  3830 
  3831 * eq_fst and eq_snd now take explicit equality parameter, thus
  3832   avoiding eqtypes. Naive rewrites:
  3833 
  3834     eq_fst = eq_fst (op =)
  3835     eq_snd = eq_snd (op =)
  3836 
  3837 * Removed deprecated apl and apr (rarely used).
  3838   Naive rewrites:
  3839 
  3840     apl (n, op) =>>= curry op n
  3841     apr (op, m) =>>= fn n => op (n, m)
  3842 
  3843 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3844 provides a reasonably efficient light-weight implementation of sets as
  3845 lists.
  3846 
  3847 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3848 few new operations; existing lookup and update are now curried to
  3849 follow natural argument order (for use with fold etc.);
  3850 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3851 
  3852 * Pure/General: output via the Isabelle channels of
  3853 writeln/warning/error etc. is now passed through Output.output, with a
  3854 hook for arbitrary transformations depending on the print_mode
  3855 (cf. Output.add_mode -- the first active mode that provides a output
  3856 function wins).  Already formatted output may be embedded into further
  3857 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3858 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3859 accommodate easy composition of diagnostic messages etc.  Programmers
  3860 rarely need to care about Output.output or Output.raw at all, with
  3861 some notable exceptions: Output.output is required when bypassing the
  3862 standard channels (writeln etc.), or in token translations to produce
  3863 properly formatted results; Output.raw is required when capturing
  3864 already output material that will eventually be presented to the user
  3865 a second time.  For the default print mode, both Output.output and
  3866 Output.raw have no effect.
  3867 
  3868 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3869 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3870 cumulative results are displayed at the end of a batch session.
  3871 
  3872 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3873 replaced by File.platform_path and File.shell_path (with appropriate
  3874 hooks).  This provides a clean interface for unusual systems where the
  3875 internal and external process view of file names are different.
  3876 
  3877 * Pure: more efficient orders for basic syntactic entities: added
  3878 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3879 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3880 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3881 orders now -- potential INCOMPATIBILITY for code that depends on a
  3882 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3883 Library.sort_strings on result).
  3884 
  3885 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3886 fold_types traverse types/terms from left to right, observing natural
  3887 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3888 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3889 
  3890 * Pure: name spaces have been refined, with significant changes of the
  3891 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3892 to extern(_table).  The plain name entry path is superceded by a
  3893 general 'naming' context, which also includes the 'policy' to produce
  3894 a fully qualified name and external accesses of a fully qualified
  3895 name; NameSpace.extend is superceded by context dependent
  3896 Sign.declare_name.  Several theory and proof context operations modify
  3897 the naming context.  Especially note Theory.restore_naming and
  3898 ProofContext.restore_naming to get back to a sane state; note that
  3899 Theory.add_path is no longer sufficient to recover from
  3900 Theory.absolute_path in particular.
  3901 
  3902 * Pure: new flags short_names (default false) and unique_names
  3903 (default true) for controlling output of qualified names.  If
  3904 short_names is set, names are printed unqualified.  If unique_names is
  3905 reset, the name prefix is reduced to the minimum required to achieve
  3906 the original result when interning again, even if there is an overlap
  3907 with earlier declarations.
  3908 
  3909 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3910 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3911 (useful for printing error messages).  INCOMPATIBILITY.
  3912 
  3913 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3914 Theory.theory are now identified, referring to the universal
  3915 Context.theory (see Pure/context.ML).  Actual signature and theory
  3916 content is managed as theory data.  The old code and interfaces were
  3917 spread over many files and structures; the new arrangement introduces
  3918 considerable INCOMPATIBILITY to gain more clarity:
  3919 
  3920   Context -- theory management operations (name, identity, inclusion,
  3921     parents, ancestors, merge, etc.), plus generic theory data;
  3922 
  3923   Sign -- logical signature and syntax operations (declaring consts,
  3924     types, etc.), plus certify/read for common entities;
  3925 
  3926   Theory -- logical theory operations (stating axioms, definitions,
  3927     oracles), plus a copy of logical signature operations (consts,
  3928     types, etc.); also a few basic management operations (Theory.copy,
  3929     Theory.merge, etc.)
  3930 
  3931 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3932 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3933 for convenience -- they merely return the theory.
  3934 
  3935 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3936 
  3937 * Pure: the Isar proof context type is already defined early in Pure
  3938 as Context.proof (note that ProofContext.context and Proof.context are
  3939 aliases, where the latter is the preferred name).  This enables other
  3940 Isabelle components to refer to that type even before Isar is present.
  3941 
  3942 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3943 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3944 any of these kinds.  For example, Sign.intern typeK is now
  3945 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3946 Theory.hide_types.  Also note that former
  3947 Theory.hide_classes/types/consts are now
  3948 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3949 internalize their arguments!  INCOMPATIBILITY.
  3950 
  3951 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3952 datatype thmref (with constructors Name and NameSelection) instead of
  3953 plain string -- INCOMPATIBILITY;
  3954 
  3955 * Pure: cases produced by proof methods specify options, where NONE
  3956 means to remove case bindings -- INCOMPATIBILITY in
  3957 (RAW_)METHOD_CASES.
  3958 
  3959 * Pure: the following operations retrieve axioms or theorems from a
  3960 theory node or theory hierarchy, respectively:
  3961 
  3962   Theory.axioms_of: theory -> (string * term) list
  3963   Theory.all_axioms_of: theory -> (string * term) list
  3964   PureThy.thms_of: theory -> (string * thm) list
  3965   PureThy.all_thms_of: theory -> (string * thm) list
  3966 
  3967 * Pure: print_tac now outputs the goal through the trace channel.
  3968 
  3969 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3970 Reference Toplevel.debug (default false) controls detailed printing
  3971 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3972 controls execution profiling -- set to 1 for time and 2 for space
  3973 (both increase the runtime).
  3974 
  3975 * Isar session: The initial use of ROOT.ML is now always timed,
  3976 i.e. the log will show the actual process times, in contrast to the
  3977 elapsed wall-clock time that the outer shell wrapper produces.
  3978 
  3979 * Simplifier: improved handling of bound variables (nameless
  3980 representation, avoid allocating new strings).  Simprocs that invoke
  3981 the Simplifier recursively should use Simplifier.inherit_bounds to
  3982 avoid local name clashes.  Failure to do so produces warnings
  3983 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3984 for further details.
  3985 
  3986 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3987 bindings for all theorems stored within a given theory; this may help
  3988 in porting non-Isar theories to Isar ones, while keeping ML proof
  3989 scripts for the time being.
  3990 
  3991 * ML operator HTML.with_charset specifies the charset begin used for
  3992 generated HTML files.  For example:
  3993 
  3994   HTML.with_charset "utf-8" use_thy "Hebrew";
  3995   HTML.with_charset "utf-8" use_thy "Chinese";
  3996 
  3997 
  3998 *** System ***
  3999 
  4000 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4001 isabelle, isatool etc.).
  4002 
  4003 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4004 isatool doc, isatool mkdir, display_drafts etc.).
  4005 
  4006 * isatool usedir: option -f allows specification of the ML file to be
  4007 used by Isabelle; default is ROOT.ML.
  4008 
  4009 * New isatool version outputs the version identifier of the Isabelle
  4010 distribution being used.
  4011 
  4012 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4013 (containing Boolean satisfiability problems) into Isabelle/HOL
  4014 theories.
  4015 
  4016 
  4017 
  4018 New in Isabelle2004 (April 2004)
  4019 --------------------------------
  4020 
  4021 *** General ***
  4022 
  4023 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4024   Replaces linorder.ML.
  4025 
  4026 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4027   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4028   (\<a>...\<z>), are now considered normal letters, and can therefore
  4029   be used anywhere where an ASCII letter (a...zA...Z) has until
  4030   now. COMPATIBILITY: This obviously changes the parsing of some
  4031   terms, especially where a symbol has been used as a binder, say
  4032   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4033   as an identifier.  Fix it by inserting a space around former
  4034   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4035   existing theory and ML files.
  4036 
  4037 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4038 
  4039 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4040   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4041   a normal (but invisible) letter. For multiple letter subscripts repeat
  4042   \<^isub> like this: x\<^isub>1\<^isub>2.
  4043 
  4044 * Pure: There are now sub-/superscripts that can span more than one
  4045   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4046   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4047   superscript. The new control characters are not identifier parts.
  4048 
  4049 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4050   content of "..." to the latex file instead of \isacntrl... . The "..."
  4051   may consist of any printable characters excluding the end bracket >.
  4052 
  4053 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4054   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4055   declare constants "final", which prevents their being given a definition
  4056   later.  It is useful for constants whose behaviour is fixed axiomatically
  4057   rather than definitionally, such as the meta-logic connectives.
  4058 
  4059 * Pure: 'instance' now handles general arities with general sorts
  4060   (i.e. intersections of classes),
  4061 
  4062 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4063   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4064   It can be changed to alter the colors/layout of generated pages.
  4065 
  4066 
  4067 *** Isar ***
  4068 
  4069 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4070   cut_tac, subgoal_tac and thin_tac:
  4071   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4072     locales are no longer forced to write Isar proof scripts.
  4073     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4074     emulations.
  4075   - INCOMPATIBILITY: names of variables to be instantiated may no
  4076     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4077     This is consistent with the instantiation attribute "where".
  4078 
  4079 * Attributes "where" and "of":
  4080   - Now take type variables of instantiated theorem into account when reading
  4081     the instantiation string.  This fixes a bug that caused instantiated
  4082     theorems to have too special types in some circumstances.
  4083   - "where" permits explicit instantiations of type variables.
  4084 
  4085 * Calculation commands "moreover" and "also" no longer interfere with
  4086   current facts ("this"), admitting arbitrary combinations with "then"
  4087   and derived forms.
  4088 
  4089 * Locales:
  4090   - Goal statements involving the context element "includes" no longer
  4091     generate theorems with internal delta predicates (those ending on
  4092     "_axioms") in the premise.
  4093     Resolve particular premise with <locale>.intro to obtain old form.
  4094   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4095     specification and "includes" elements in goal statement.
  4096   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4097     [intro?] and [elim?] (respectively) by default.
  4098   - Experimental command for instantiation of locales in proof contexts:
  4099         instantiate <label>[<attrs>]: <loc>
  4100     Instantiates locale <loc> and adds all its theorems to the current context
  4101     taking into account their attributes.  Label and attrs are optional
  4102     modifiers, like in theorem declarations.  If present, names of
  4103     instantiated theorems are qualified with <label>, and the attributes
  4104     <attrs> are applied after any attributes these theorems might have already.
  4105       If the locale has assumptions, a chained fact of the form
  4106     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4107     are derived.  The command does not support old-style locales declared
  4108     with "locale (open)".
  4109       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4110 
  4111 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4112   (Isar) contexts.
  4113 
  4114 
  4115 *** HOL ***
  4116 
  4117 * Proof import: new image HOL4 contains the imported library from
  4118   the HOL4 system with about 2500 theorems. It is imported by
  4119   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4120   can be used like any other Isabelle image.  See
  4121   HOL/Import/HOL/README for more information.
  4122 
  4123 * Simplifier:
  4124   - Much improved handling of linear and partial orders.
  4125     Reasoners for linear and partial orders are set up for type classes
  4126     "linorder" and "order" respectively, and are added to the default simpset
  4127     as solvers.  This means that the simplifier can build transitivity chains
  4128     to solve goals from the assumptions.
  4129   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4130     of blast or auto after simplification become unnecessary because the goal
  4131     is solved by simplification already.
  4132 
  4133 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4134     all proved in axiomatic type classes for semirings, rings and fields.
  4135 
  4136 * Numerics:
  4137   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4138     now formalized using the Ring_and_Field theory mentioned above.
  4139   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4140     than before, because now they are set up once in a generic manner.
  4141   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4142     Look for the general versions in Ring_and_Field (and Power if they concern
  4143     exponentiation).
  4144 
  4145 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4146 
  4147 * Records:
  4148   - Record types are now by default printed with their type abbreviation
  4149     instead of the list of all field types. This can be configured via
  4150     the reference "print_record_type_abbr".
  4151   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4152     (not enabled by default).
  4153   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4154     EX x. x = sel r to True (not enabled by default).
  4155   - Tactic "record_split_simp_tac" to split and simplify records added.
  4156 
  4157 * 'specification' command added, allowing for definition by
  4158   specification.  There is also an 'ax_specification' command that
  4159   introduces the new constants axiomatically.
  4160 
  4161 * arith(_tac) is now able to generate counterexamples for reals as well.
  4162 
  4163 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4164 
  4165 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4166   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4167 
  4168 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4169   matrix theory to linear programming.
  4170 
  4171 * Unions and Intersections:
  4172   The latex output syntax of UN and INT has been changed
  4173   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4174   i.e. the index formulae has become a subscript.
  4175   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4176 
  4177 * Unions and Intersections over Intervals:
  4178   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4179   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4180   like in normal math, and corresponding versions for < and for intersection.
  4181 
  4182 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4183   lexicographic dictonary ordering has been added as "lexord".
  4184 
  4185 * ML: the legacy theory structures Int and List have been removed. They had
  4186   conflicted with ML Basis Library structures having the same names.
  4187 
  4188 * 'refute' command added to search for (finite) countermodels.  Only works
  4189   for a fragment of HOL.  The installation of an external SAT solver is
  4190   highly recommended.  See "HOL/Refute.thy" for details.
  4191 
  4192 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4193   formulae under an assignment of free variables to random values.
  4194   In contrast to 'refute', it can deal with inductive datatypes,
  4195   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4196   for examples.
  4197 
  4198 
  4199 *** HOLCF ***
  4200 
  4201 * Streams now come with concatenation and are part of the HOLCF image
  4202 
  4203 
  4204 
  4205 New in Isabelle2003 (May 2003)
  4206 ------------------------------
  4207 
  4208 *** General ***
  4209 
  4210 * Provers/simplifier:
  4211 
  4212   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4213     Assumptions are now subject to complete mutual simplification,
  4214     not just from left to right. The simplifier now preserves
  4215     the order of assumptions.
  4216 
  4217     Potential INCOMPATIBILITY:
  4218 
  4219     -- simp sometimes diverges where the old version did
  4220        not, e.g. invoking simp on the goal
  4221 
  4222         [| P (f x); y = x; f x = f y |] ==> Q
  4223 
  4224        now gives rise to the infinite reduction sequence
  4225 
  4226         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4227 
  4228        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4229        kind of problem.
  4230 
  4231     -- Tactics combining classical reasoner and simplification (such as auto)
  4232        are also affected by this change, because many of them rely on
  4233        simp. They may sometimes diverge as well or yield a different numbers
  4234        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4235        in case of problems. Sometimes subsequent calls to the classical
  4236        reasoner will fail because a preceeding call to the simplifier too
  4237        eagerly simplified the goal, e.g. deleted redundant premises.
  4238 
  4239   - The simplifier trace now shows the names of the applied rewrite rules
  4240 
  4241   - You can limit the number of recursive invocations of the simplifier
  4242     during conditional rewriting (where the simplifie tries to solve the
  4243     conditions before applying the rewrite rule):
  4244     ML "simp_depth_limit := n"
  4245     where n is an integer. Thus you can force termination where previously
  4246     the simplifier would diverge.
  4247 
  4248   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4249 
  4250   - No longer aborts on failed congruence proof.  Instead, the
  4251     congruence is ignored.
  4252 
  4253 * Pure: New generic framework for extracting programs from constructive
  4254   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4255   as HOL/Extraction for some case studies.
  4256 
  4257 * Pure: The main goal of the proof state is no longer shown by default, only
  4258 the subgoals. This behaviour is controlled by a new flag.
  4259    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4260 (ML: Proof.show_main_goal).
  4261 
  4262 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4263 rules whose conclusion matches subgoal 1:
  4264       PG menu: Isabelle/Isar -> Show me -> matching rules
  4265 The rules are ordered by how closely they match the subgoal.
  4266 In particular, rules that solve a subgoal outright are displayed first
  4267 (or rather last, the way they are printed).
  4268 (ML: ProofGeneral.print_intros())
  4269 
  4270 * Pure: New flag trace_unify_fail causes unification to print
  4271 diagnostic information (PG: in trace buffer) when it fails. This is
  4272 useful for figuring out why single step proofs like rule, erule or
  4273 assumption failed.
  4274 
  4275 * Pure: Locale specifications now produce predicate definitions
  4276 according to the body of text (covering assumptions modulo local
  4277 definitions); predicate "loc_axioms" covers newly introduced text,
  4278 while "loc" is cumulative wrt. all included locale expressions; the
  4279 latter view is presented only on export into the global theory
  4280 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4281 on the old view without predicates;
  4282 
  4283 * Pure: predefined locales "var" and "struct" are useful for sharing
  4284 parameters (as in CASL, for example); just specify something like
  4285 ``var x + var y + struct M'' as import;
  4286 
  4287 * Pure: improved thms_containing: proper indexing of facts instead of
  4288 raw theorems; check validity of results wrt. current name space;
  4289 include local facts of proof configuration (also covers active
  4290 locales), cover fixed variables in index; may use "_" in term
  4291 specification; an optional limit for the number of printed facts may
  4292 be given (the default is 40);
  4293 
  4294 * Pure: disallow duplicate fact bindings within new-style theory files
  4295 (batch-mode only);
  4296 
  4297 * Provers: improved induct method: assumptions introduced by case
  4298 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4299 the goal statement); "foo" still refers to all facts collectively;
  4300 
  4301 * Provers: the function blast.overloaded has been removed: all constants
  4302 are regarded as potentially overloaded, which improves robustness in exchange
  4303 for slight decrease in efficiency;
  4304 
  4305 * Provers/linorder: New generic prover for transitivity reasoning over
  4306 linear orders.  Note: this prover is not efficient!
  4307 
  4308 * Isar: preview of problems to finish 'show' now produce an error
  4309 rather than just a warning (in interactive mode);
  4310 
  4311 
  4312 *** HOL ***
  4313 
  4314 * arith(_tac)
  4315 
  4316  - Produces a counter example if it cannot prove a goal.
  4317    Note that the counter example may be spurious if the goal is not a formula
  4318    of quantifier-free linear arithmetic.
  4319    In ProofGeneral the counter example appears in the trace buffer.
  4320 
  4321  - Knows about div k and mod k where k is a numeral of type nat or int.
  4322 
  4323  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4324    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4325    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4326 
  4327 * simp's arithmetic capabilities have been enhanced a bit: it now
  4328 takes ~= in premises into account (by performing a case split);
  4329 
  4330 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4331 are distributed over a sum of terms;
  4332 
  4333 * New tactic "trans_tac" and method "trans" instantiate
  4334 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4335 "<=", "<" and "=").
  4336 
  4337 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4338 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4339 
  4340 * 'typedef' command has new option "open" to suppress the set
  4341 definition;
  4342 
  4343 * functions Min and Max on finite sets have been introduced (theory
  4344 Finite_Set);
  4345 
  4346 * attribute [symmetric] now works for relations as well; it turns
  4347 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4348 
  4349 * induct over a !!-quantified statement (say !!x1..xn):
  4350   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4351 
  4352 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4353 %x. None. Warning: empty_def now refers to the previously hidden definition
  4354 of the empty set.
  4355 
  4356 * Algebra: formalization of classical algebra.  Intended as base for
  4357 any algebraic development in Isabelle.  Currently covers group theory
  4358 (up to Sylow's theorem) and ring theory (Universal Property of
  4359 Univariate Polynomials).  Contributions welcome;
  4360 
  4361 * GroupTheory: deleted, since its material has been moved to Algebra;
  4362 
  4363 * Complex: new directory of the complex numbers with numeric constants,
  4364 nonstandard complex numbers, and some complex analysis, standard and
  4365 nonstandard (Jacques Fleuriot);
  4366 
  4367 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4368 
  4369 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4370 Fleuriot);
  4371 
  4372 * Real/HahnBanach: updated and adapted to locales;
  4373 
  4374 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4375 Gray and Kramer);
  4376 
  4377 * UNITY: added the Meier-Sanders theory of progress sets;
  4378 
  4379 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4380 as abstract algorithms, instantiated to the JVM;
  4381 
  4382 * Bali: Java source language formalization. Type system, operational
  4383 semantics, axiomatic semantics. Supported language features:
  4384 classes, interfaces, objects,virtual methods, static methods,
  4385 static/instance fields, arrays, access modifiers, definite
  4386 assignment, exceptions.
  4387 
  4388 
  4389 *** ZF ***
  4390 
  4391 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4392 universe, etc.);
  4393 
  4394 * Main ZF: virtually all theories converted to new-style format;
  4395 
  4396 
  4397 *** ML ***
  4398 
  4399 * Pure: Tactic.prove provides sane interface for internal proofs;
  4400 omits the infamous "standard" operation, so this is more appropriate
  4401 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4402 
  4403 * Pure: improved error reporting of simprocs;
  4404 
  4405 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4406 up simprocs;
  4407 
  4408 
  4409 *** Document preparation ***
  4410 
  4411 * uses \par instead of \\ for line breaks in theory text. This may
  4412 shift some page breaks in large documents. To get the old behaviour
  4413 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4414 
  4415 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4416 other packages
  4417 
  4418 * \<euro> now needs package babel/greek instead of marvosym (which
  4419 broke \Rightarrow)
  4420 
  4421 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4422 textcomp package)
  4423 
  4424 
  4425 
  4426 New in Isabelle2002 (March 2002)
  4427 --------------------------------
  4428 
  4429 *** Document preparation ***
  4430 
  4431 * greatly simplified document preparation setup, including more
  4432 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4433 instructive isatool mkdir; users should basically be able to get
  4434 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4435 users may run a separate document processing stage manually like this:
  4436 "isatool usedir -D output HOL Test && isatool document Test/output";
  4437 
  4438 * theory dependency graph may now be incorporated into documents;
  4439 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4440 with \includegraphics of LaTeX;
  4441 
  4442 * proper spacing of consecutive markup elements, especially text
  4443 blocks after section headings;
  4444 
  4445 * support bold style (for single symbols only), input syntax is like
  4446 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4447 
  4448 * \<bullet> is now output as bold \cdot by default, which looks much
  4449 better in printed text;
  4450 
  4451 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4452 note that these symbols are currently unavailable in Proof General /
  4453 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4454 
  4455 * isatool latex no longer depends on changed TEXINPUTS, instead
  4456 isatool document copies the Isabelle style files to the target
  4457 location;
  4458 
  4459 
  4460 *** Isar ***
  4461 
  4462 * Pure/Provers: improved proof by cases and induction;
  4463   - 'case' command admits impromptu naming of parameters (such as
  4464     "case (Suc n)");
  4465   - 'induct' method divinates rule instantiation from the inductive
  4466     claim; no longer requires excessive ?P bindings for proper
  4467     instantiation of cases;
  4468   - 'induct' method properly enumerates all possibilities of set/type
  4469     rules; as a consequence facts may be also passed through *type*
  4470     rules without further ado;
  4471   - 'induct' method now derives symbolic cases from the *rulified*
  4472     rule (before it used to rulify cases stemming from the internal
  4473     atomized version); this means that the context of a non-atomic
  4474     statement becomes is included in the hypothesis, avoiding the
  4475     slightly cumbersome show "PROP ?case" form;
  4476   - 'induct' may now use elim-style induction rules without chaining
  4477     facts, using ``missing'' premises from the goal state; this allows
  4478     rules stemming from inductive sets to be applied in unstructured
  4479     scripts, while still benefitting from proper handling of non-atomic
  4480     statements; NB: major inductive premises need to be put first, all
  4481     the rest of the goal is passed through the induction;
  4482   - 'induct' proper support for mutual induction involving non-atomic
  4483     rule statements (uses the new concept of simultaneous goals, see
  4484     below);
  4485   - append all possible rule selections, but only use the first
  4486     success (no backtracking);
  4487   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4488   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4489   - added 'print_induct_rules' (covered by help item in recent Proof
  4490     General versions);
  4491   - moved induct/cases attributes to Pure, methods to Provers;
  4492   - generic method setup instantiated for FOL and HOL;
  4493 
  4494 * Pure: support multiple simultaneous goal statements, for example
  4495 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4496 meta-level mechanism, this acts as if several individual goals had
  4497 been stated separately; in particular common proof methods need to be
  4498 repeated in order to cover all claims; note that a single elimination
  4499 step is *not* sufficient to establish the two conjunctions, so this
  4500 fails:
  4501 
  4502   assume "A & B" then have A and B ..   (*".." fails*)
  4503 
  4504 better use "obtain" in situations as above; alternative refer to
  4505 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4506 
  4507 * Pure: proper integration with ``locales''; unlike the original
  4508 version by Florian Kammller, Isar locales package high-level proof
  4509 contexts rather than raw logical ones (e.g. we admit to include
  4510 attributes everywhere); operations on locales include merge and
  4511 rename; support for implicit arguments (``structures''); simultaneous
  4512 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4513 some examples;
  4514 
  4515 * Pure: the following commands have been ``localized'', supporting a
  4516 target locale specification "(in name)": 'lemma', 'theorem',
  4517 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4518 stored both within the locale and at the theory level (exported and
  4519 qualified by the locale name);
  4520 
  4521 * Pure: theory goals may now be specified in ``long'' form, with
  4522 ad-hoc contexts consisting of arbitrary locale elements. for example
  4523 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4524 definitions may be given, too); the result is a meta-level rule with
  4525 the context elements being discharged in the obvious way;
  4526 
  4527 * Pure: new proof command 'using' allows to augment currently used
  4528 facts after a goal statement ('using' is syntactically analogous to
  4529 'apply', but acts on the goal's facts only); this allows chained facts
  4530 to be separated into parts given before and after a claim, as in
  4531 ``from a and b have C using d and e <proof>'';
  4532 
  4533 * Pure: renamed "antecedent" case to "rule_context";
  4534 
  4535 * Pure: new 'judgment' command records explicit information about the
  4536 object-logic embedding (used by several tools internally); no longer
  4537 use hard-wired "Trueprop";
  4538 
  4539 * Pure: added 'corollary' command;
  4540 
  4541 * Pure: fixed 'token_translation' command;
  4542 
  4543 * Pure: removed obsolete 'exported' attribute;
  4544 
  4545 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4546 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4547 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4548 
  4549 * Pure: method 'atomize' presents local goal premises as object-level
  4550 statements (atomic meta-level propositions); setup controlled via
  4551 rewrite rules declarations of 'atomize' attribute; example
  4552 application: 'induct' method with proper rule statements in improper
  4553 proof *scripts*;
  4554 
  4555 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4556 now consider the syntactic context of assumptions, giving a better
  4557 chance to get type-inference of the arguments right (this is
  4558 especially important for locales);
  4559 
  4560 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4561 mode;
  4562 
  4563 * Pure/obtain: the formal conclusion "thesis", being marked as
  4564 ``internal'', may no longer be reference directly in the text;
  4565 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4566 situations;
  4567 
  4568 * Pure: generic 'sym' attribute which declares a rule both as pure
  4569 'elim?' and for the 'symmetric' operation;
  4570 
  4571 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4572 text; the fixed correlation with particular command syntax has been
  4573 discontinued;
  4574 
  4575 * Pure: new method 'rules' is particularly well-suited for proof
  4576 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4577 but often produces more compact proof terms with less detours;
  4578 
  4579 * Pure/Provers/classical: simplified integration with pure rule
  4580 attributes and methods; the classical "intro?/elim?/dest?"
  4581 declarations coincide with the pure ones; the "rule" method no longer
  4582 includes classically swapped intros; "intro" and "elim" methods no
  4583 longer pick rules from the context; also got rid of ML declarations
  4584 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4585 INCOMPATIBILITY;
  4586 
  4587 * Provers/classical: attribute 'swapped' produces classical inversions
  4588 of introduction rules;
  4589 
  4590 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4591 rules instead of full simplifier context; 'iff' attribute handles
  4592 conditional rules;
  4593 
  4594 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4595 
  4596 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4597 "(permissive)" option to recover old behavior;
  4598 
  4599 * HOL: 'inductive' no longer features separate (collective) attributes
  4600 for 'intros' (was found too confusing);
  4601 
  4602 * HOL: properly declared induction rules less_induct and
  4603 wf_induct_rule;
  4604 
  4605 
  4606 *** HOL ***
  4607 
  4608 * HOL: moved over to sane numeral syntax; the new policy is as
  4609 follows:
  4610 
  4611   - 0 and 1 are polymorphic constants, which are defined on any
  4612   numeric type (nat, int, real etc.);
  4613 
  4614   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4615   binary representation internally;
  4616 
  4617   - type nat has special constructor Suc, and generally prefers Suc 0
  4618   over 1::nat and Suc (Suc 0) over 2::nat;
  4619 
  4620 This change may cause significant problems of INCOMPATIBILITY; here
  4621 are some hints on converting existing sources:
  4622 
  4623   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4624   entities, so expressions involving "-" (unary or binary minus) need
  4625   to be spaced properly;
  4626 
  4627   - existing occurrences of "1" may need to be constraint "1::nat" or
  4628   even replaced by Suc 0; similar for old "2";
  4629 
  4630   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4631 
  4632   - remove all special provisions on numerals in proofs;
  4633 
  4634 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4635 representation (depends on bin_arith_simps in the default context);
  4636 
  4637 * HOL: symbolic syntax for x^2 (numeral 2);
  4638 
  4639 * HOL: the class of all HOL types is now called "type" rather than
  4640 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4641 in axclass/classes, instance/arities, and (usually rare) occurrences
  4642 in typings (of consts etc.); internally the class is called
  4643 "HOL.type", ML programs should refer to HOLogic.typeS;
  4644 
  4645 * HOL/record package improvements:
  4646   - new derived operations "fields" to build a partial record section,
  4647     "extend" to promote a fixed record to a record scheme, and
  4648     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4649     declared as simp by default;
  4650   - shared operations ("more", "fields", etc.) now need to be always
  4651     qualified) --- potential INCOMPATIBILITY;
  4652   - removed "make_scheme" operations (use "make" with "extend") --
  4653     INCOMPATIBILITY;
  4654   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4655   - provides cases/induct rules for use with corresponding Isar
  4656     methods (for concrete records, record schemes, concrete more
  4657     parts, and schematic more parts -- in that order);
  4658   - internal definitions directly based on a light-weight abstract
  4659     theory of product types over typedef rather than datatype;
  4660 
  4661 * HOL: generic code generator for generating executable ML code from
  4662 specifications; specific support for HOL constructs such as inductive
  4663 datatypes and sets, as well as recursive functions; can be invoked
  4664 via 'generate_code' theory section;
  4665 
  4666 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4667 
  4668 * HOL: consolidated and renamed several theories.  In particular:
  4669         Ord.thy has been absorbed into HOL.thy
  4670         String.thy has been absorbed into List.thy
  4671 
  4672 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4673 (beware of argument permutation!);
  4674 
  4675 * HOL: linorder_less_split superseded by linorder_cases;
  4676 
  4677 * HOL/List: "nodups" renamed to "distinct";
  4678 
  4679 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4680 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4681   - Ex_def has changed, now need to use some_eq_ex
  4682 
  4683 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4684 in this (rare) case use:
  4685 
  4686   delSWrapper "split_all_tac"
  4687   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4688 
  4689 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4690 MAY FAIL;
  4691 
  4692 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4693 Isabelle's type classes, ^ on functions and relations has too general
  4694 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4695 necessary to attach explicit type constraints;
  4696 
  4697 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4698 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4699 renamed accordingly (eg "compI" -> "rel_compI").
  4700 
  4701 * HOL: syntax translations now work properly with numerals and records
  4702 expressions;
  4703 
  4704 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4705 of "lam" -- INCOMPATIBILITY;
  4706 
  4707 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4708 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4709 renamed "Product_Type.unit";
  4710 
  4711 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4712 
  4713 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4714 the "cases" method);
  4715 
  4716 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4717 Florian Kammller);
  4718 
  4719 * HOL/IMP: updated and converted to new-style theory format; several
  4720 parts turned into readable document, with proper Isar proof texts and
  4721 some explanations (by Gerwin Klein);
  4722 
  4723 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4724 
  4725 * HOL-Hyperreal is now a logic image;
  4726 
  4727 
  4728 *** HOLCF ***
  4729 
  4730 * Isar: consts/constdefs supports mixfix syntax for continuous
  4731 operations;
  4732 
  4733 * Isar: domain package adapted to new-style theory format, e.g. see
  4734 HOLCF/ex/Dnat.thy;
  4735 
  4736 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4737 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4738 lift.induct_tac, always use UU instead of Undef;
  4739 
  4740 * HOLCF/IMP: updated and converted to new-style theory;
  4741 
  4742 
  4743 *** ZF ***
  4744 
  4745 * Isar: proper integration of logic-specific tools and packages,
  4746 including theory commands '(co)inductive', '(co)datatype',
  4747 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4748 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4749 
  4750 * theory Main no longer includes AC; for the Axiom of Choice, base
  4751 your theory on Main_ZFC;
  4752 
  4753 * the integer library now covers quotients and remainders, with many
  4754 laws relating division to addition, multiplication, etc.;
  4755 
  4756 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4757 typeless version of the formalism;
  4758 
  4759 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4760 format;
  4761 
  4762 * ZF/Induct: new directory for examples of inductive definitions,
  4763 including theory Multiset for multiset orderings; converted to
  4764 new-style theory format;
  4765 
  4766 * ZF: many new theorems about lists, ordinals, etc.;
  4767 
  4768 
  4769 *** General ***
  4770 
  4771 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4772 variable proof controls level of detail: 0 = no proofs (only oracle
  4773 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4774 also ref manual for further ML interfaces;
  4775 
  4776 * Pure/axclass: removed obsolete ML interface
  4777 goal_subclass/goal_arity;
  4778 
  4779 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4780 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4781 separate tokens, so expressions involving minus need to be spaced
  4782 properly;
  4783 
  4784 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4785 rather than "infixl" or "infixr";
  4786 
  4787 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4788 sort constraint specifications in type inference; e.g. "x::_::foo"
  4789 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4790 type variable);
  4791 
  4792 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4793 control output of nested => (types); the default behavior is
  4794 "type_brackets";
  4795 
  4796 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4797 tokens into AST constants;
  4798 
  4799 * Pure/syntax: prefer later declarations of translations and print
  4800 translation functions; potential INCOMPATIBILITY: need to reverse
  4801 multiple declarations for same syntax element constant;
  4802 
  4803 * Pure/show_hyps reset by default (in accordance to existing Isar
  4804 practice);
  4805 
  4806 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4807 addSafter;
  4808 
  4809 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4810 as well;
  4811 
  4812 * system: tested support for MacOS X; should be able to get Isabelle +
  4813 Proof General to work in a plain Terminal after installing Poly/ML
  4814 (e.g. from the Isabelle distribution area) and GNU bash alone
  4815 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4816 support requires further installations, e.g. from
  4817 http://fink.sourceforge.net/);
  4818 
  4819 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4820 
  4821 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4822 of 40 MB), cf. ML_OPTIONS;
  4823 
  4824 * system: Proof General keywords specification is now part of the
  4825 Isabelle distribution (see etc/isar-keywords.el);
  4826 
  4827 * system: support for persistent Proof General sessions (refrain from
  4828 outdating all loaded theories on startup); user may create writable
  4829 logic images like this: ``isabelle -q HOL Test'';
  4830 
  4831 * system: smart selection of Isabelle process versus Isabelle
  4832 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4833 run both "isabelle" and "Isabelle" even if file names are badly
  4834 damaged (executable inspects the case of the first letter of its own
  4835 name); added separate "isabelle-process" and "isabelle-interface";
  4836 
  4837 * system: refrain from any attempt at filtering input streams; no
  4838 longer support ``8bit'' encoding of old isabelle font, instead proper
  4839 iso-latin characters may now be used; the related isatools
  4840 "symbolinput" and "nonascii" have disappeared as well;
  4841 
  4842 * system: removed old "xterm" interface (the print modes "xterm" and
  4843 "xterm_color" are still available for direct use in a suitable
  4844 terminal);
  4845 
  4846 
  4847 
  4848 New in Isabelle99-2 (February 2001)
  4849 -----------------------------------
  4850 
  4851 *** Overview of INCOMPATIBILITIES ***
  4852 
  4853 * HOL: please note that theories in the Library and elsewhere often use the
  4854 new-style (Isar) format; to refer to their theorems in an ML script you must
  4855 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4856 
  4857 * HOL: inductive package no longer splits induction rule aggressively,
  4858 but only as far as specified by the introductions given; the old
  4859 format may be recovered via ML function complete_split_rule or attribute
  4860 'split_rule (complete)';
  4861 
  4862 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4863 gfp_Tarski to gfp_unfold;
  4864 
  4865 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4866 
  4867 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4868 relation); infix "^^" has been renamed "``"; infix "``" has been
  4869 renamed "`"; "univalent" has been renamed "single_valued";
  4870 
  4871 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4872 operation;
  4873 
  4874 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4875 
  4876 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4877 
  4878 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4879 consequence, it is no longer monotonic wrt. the local goal context
  4880 (which is now passed through the inductive cases);
  4881 
  4882 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4883 \<gg> to \<ggreater>;
  4884 
  4885 
  4886 *** Document preparation ***
  4887 
  4888 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4889 available: are "it" for near math-mode best-style output, "sl" for
  4890 slanted text style, and "tt" for plain type-writer; if no
  4891 \isabellestyle command is given, output is according to slanted
  4892 type-writer);
  4893 
  4894 * support sub/super scripts (for single symbols only), input syntax is
  4895 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4896 
  4897 * some more standard symbols; see Appendix A of the system manual for
  4898 the complete list of symbols defined in isabellesym.sty;
  4899 
  4900 * improved isabelle style files; more abstract symbol implementation
  4901 (should now use \isamath{...} and \isatext{...} in custom symbol
  4902 definitions);
  4903 
  4904 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4905 state; Note that presentation of goal states does not conform to
  4906 actual human-readable proof documents.  Please do not include goal
  4907 states into document output unless you really know what you are doing!
  4908 
  4909 * proper indentation of antiquoted output with proportional LaTeX
  4910 fonts;
  4911 
  4912 * no_document ML operator temporarily disables LaTeX document
  4913 generation;
  4914 
  4915 * isatool unsymbolize tunes sources for plain ASCII communication;
  4916 
  4917 
  4918 *** Isar ***
  4919 
  4920 * Pure: Isar now suffers initial goal statements to contain unbound
  4921 schematic variables (this does not conform to actual readable proof
  4922 documents, due to unpredictable outcome and non-compositional proof
  4923 checking); users who know what they are doing may use schematic goals
  4924 for Prolog-style synthesis of proven results;
  4925 
  4926 * Pure: assumption method (an implicit finishing) now handles actual
  4927 rules as well;
  4928 
  4929 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4930 initial goal, declare "that" only as Pure intro (only for single
  4931 steps); the "that" rule assumption may now be involved in implicit
  4932 finishing, thus ".." becomes a feasible for trivial obtains;
  4933 
  4934 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4935 instance proofs may be performed by "..";
  4936 
  4937 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4938 statements as well;
  4939 
  4940 * Pure: more robust selection of calculational rules;
  4941 
  4942 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4943 rule (as well as the assumption rule);
  4944 
  4945 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4946 lemmas, using the graph browser tool;
  4947 
  4948 * Pure: predict failure of "show" in interactive mode;
  4949 
  4950 * Pure: 'thms_containing' now takes actual terms as arguments;
  4951 
  4952 * HOL: improved method 'induct' --- now handles non-atomic goals
  4953 (potential INCOMPATIBILITY); tuned error handling;
  4954 
  4955 * HOL: cases and induct rules now provide explicit hints about the
  4956 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4957 any remaining facts are inserted into the goal verbatim;
  4958 
  4959 * HOL: local contexts (aka cases) may now contain term bindings as
  4960 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4961 the result to be shown in each case;
  4962 
  4963 * HOL: added 'recdef_tc' command;
  4964 
  4965 * isatool convert assists in eliminating legacy ML scripts;
  4966 
  4967 
  4968 *** HOL ***
  4969 
  4970 * HOL/Library: a collection of generic theories to be used together
  4971 with main HOL; the theory loader path already includes this directory
  4972 by default; the following existing theories have been moved here:
  4973 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4974 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4975 
  4976 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4977 modelling and verification task performed in Isabelle/HOL +
  4978 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4979 
  4980 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4981 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4982 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4983 'domain', this makes the theory consistent with mathematical
  4984 literature;
  4985 
  4986 * HOL basics: added overloaded operations "inverse" and "divide"
  4987 (infix "/"), syntax for generic "abs" operation, generic summation
  4988 operator \<Sum>;
  4989 
  4990 * HOL/typedef: simplified package, provide more useful rules (see also
  4991 HOL/subset.thy);
  4992 
  4993 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4994 now expressed as a proper nested rule (old-style tactic scripts may
  4995 require atomize_strip_tac to cope with non-atomic premises);
  4996 
  4997 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4998 to "split_conv" (old name still available for compatibility);
  4999 
  5000 * HOL: improved concrete syntax for strings (e.g. allows translation
  5001 rules with string literals);
  5002 
  5003 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5004  and Fleuriot's mechanization of analysis, including the transcendental
  5005  functions for the reals;
  5006 
  5007 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5008 
  5009 
  5010 *** CTT ***
  5011 
  5012 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5013 "lam" is displayed as TWO lambda-symbols
  5014 
  5015 * CTT: theory Main now available, containing everything (that is, Bool
  5016 and Arith);
  5017 
  5018 
  5019 *** General ***
  5020 
  5021 * Pure: the Simplifier has been implemented properly as a derived rule
  5022 outside of the actual kernel (at last!); the overall performance
  5023 penalty in practical applications is about 50%, while reliability of
  5024 the Isabelle inference kernel has been greatly improved;
  5025 
  5026 * print modes "brackets" and "no_brackets" control output of nested =>
  5027 (types) and ==> (props); the default behaviour is "brackets";
  5028 
  5029 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5030 as assumptions as well;
  5031 
  5032 * system: support Poly/ML 4.0;
  5033 
  5034 * system: isatool install handles KDE version 1 or 2;
  5035 
  5036 
  5037 
  5038 New in Isabelle99-1 (October 2000)
  5039 ----------------------------------
  5040 
  5041 *** Overview of INCOMPATIBILITIES ***
  5042 
  5043 * HOL: simplification of natural numbers is much changed; to partly
  5044 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5045 issue the following ML commands:
  5046 
  5047   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5048   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5049 
  5050 * HOL: simplification no longer dives into case-expressions; this is
  5051 controlled by "t.weak_case_cong" for each datatype t;
  5052 
  5053 * HOL: nat_less_induct renamed to less_induct;
  5054 
  5055 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5056 fixsome to patch .thy and .ML sources automatically;
  5057 
  5058   select_equality  -> some_equality
  5059   select_eq_Ex     -> some_eq_ex
  5060   selectI2EX       -> someI2_ex
  5061   selectI2         -> someI2
  5062   selectI          -> someI
  5063   select1_equality -> some1_equality
  5064   Eps_sym_eq       -> some_sym_eq_trivial
  5065   Eps_eq           -> some_eq_trivial
  5066 
  5067 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5068 
  5069 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5070 instead);
  5071 
  5072 * HOL: the recursion equations generated by 'recdef' are now called
  5073 f.simps instead of f.rules;
  5074 
  5075 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5076 
  5077 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5078 sometimes be needed;
  5079 
  5080 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5081 
  5082 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5083 
  5084 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5085 product is now "<*>" instead of "Times"; the lexicographic product is
  5086 now "<*lex*>" instead of "**";
  5087 
  5088 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5089 of main HOL, but was unused); better use HOL's datatype package;
  5090 
  5091 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5092 the old syntax may be recovered as follows:
  5093 
  5094   syntax (symbols)
  5095     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5096       (infixl "\\<oplus>" 100)
  5097 
  5098 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5099 
  5100 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5101 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5102 internally;
  5103 
  5104 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5105 changed from A/r to A//r;
  5106 
  5107 * ZF: new treatment of arithmetic (nat & int) may break some old
  5108 proofs;
  5109 
  5110 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5111 rulify -> rule_format, elimify -> elim_format, ...);
  5112 
  5113 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5114 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5115 should have to change intro!! to intro? only); replaced "delrule" by
  5116 "rule del";
  5117 
  5118 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5119 
  5120 * Provers: strengthened force_tac by using new first_best_tac;
  5121 
  5122 * LaTeX document preparation: several changes of isabelle.sty (see
  5123 lib/texinputs);
  5124 
  5125 
  5126 *** Document preparation ***
  5127 
  5128 * formal comments (text blocks etc.) in new-style theories may now
  5129 contain antiquotations of thm/prop/term/typ/text to be presented
  5130 according to latex print mode; concrete syntax is like this:
  5131 @{term[show_types] "f(x) = a + x"};
  5132 
  5133 * isatool mkdir provides easy setup of Isabelle session directories,
  5134 including proper document sources;
  5135 
  5136 * generated LaTeX sources are now deleted after successful run
  5137 (isatool document -c); may retain a copy somewhere else via -D option
  5138 of isatool usedir;
  5139 
  5140 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5141 style files, achieving self-contained LaTeX sources and simplifying
  5142 LaTeX debugging;
  5143 
  5144 * old-style theories now produce (crude) LaTeX output as well;
  5145 
  5146 * browser info session directories are now self-contained (may be put
  5147 on WWW server seperately); improved graphs of nested sessions; removed
  5148 graph for 'all sessions';
  5149 
  5150 * several improvements in isabelle style files; \isabellestyle{it}
  5151 produces fake math mode output; \isamarkupheader is now \section by
  5152 default; see lib/texinputs/isabelle.sty etc.;
  5153 
  5154 
  5155 *** Isar ***
  5156 
  5157 * Isar/Pure: local results and corresponding term bindings are now
  5158 subject to Hindley-Milner polymorphism (similar to ML); this
  5159 accommodates incremental type-inference very nicely;
  5160 
  5161 * Isar/Pure: new derived language element 'obtain' supports
  5162 generalized existence reasoning;
  5163 
  5164 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5165 support accumulation of results, without applying any rules yet;
  5166 useful to collect intermediate results without explicit name
  5167 references, and for use with transitivity rules with more than 2
  5168 premises;
  5169 
  5170 * Isar/Pure: scalable support for case-analysis type proofs: new
  5171 'case' language element refers to local contexts symbolically, as
  5172 produced by certain proof methods; internally, case names are attached
  5173 to theorems as "tags";
  5174 
  5175 * Isar/Pure: theory command 'hide' removes declarations from
  5176 class/type/const name spaces;
  5177 
  5178 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5179 indicate potential overloading;
  5180 
  5181 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5182 
  5183 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5184 "{a,b,c}" instead of {a,b,c};
  5185 
  5186 * Isar/Pure now provides its own version of intro/elim/dest
  5187 attributes; useful for building new logics, but beware of confusion
  5188 with the version in Provers/classical;
  5189 
  5190 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5191 case name 'antecedent';
  5192 
  5193 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5194 to the current context is now done automatically);
  5195 
  5196 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5197 for definining proof methods in ML;
  5198 
  5199 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5200 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5201 most cases, one should have to change intro!! to intro? only);
  5202 replaced "delrule" by "rule del";
  5203 
  5204 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5205 'symmetric' attribute (the latter supercedes [RS sym]);
  5206 
  5207 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5208 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5209 well (including splits);
  5210 
  5211 * Isar/Provers: Simplifier and Classical methods now support all kind
  5212 of modifiers used in the past, including 'cong', 'iff', etc.
  5213 
  5214 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5215 of Simplifier and Classical reasoner);
  5216 
  5217 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5218 now support named cases; major packages (inductive, datatype, primrec,
  5219 recdef) support case names and properly name parameters;
  5220 
  5221 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5222 monotonicity conditions are extracted to be proven at end of
  5223 calculations;
  5224 
  5225 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5226 method anyway;
  5227 
  5228 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5229 split_if split_if_asm; datatype package provides theorems foo.splits =
  5230 foo.split foo.split_asm for each datatype;
  5231 
  5232 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5233 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5234 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5235 use "(cases (simplified))" method in proper proof texts);
  5236 
  5237 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5238 
  5239 * Isar: names of theorems etc. may be natural numbers as well;
  5240 
  5241 * Isar: 'pr' command: optional arguments for goals_limit and
  5242 ProofContext.prems_limit; no longer prints theory contexts, but only
  5243 proof states;
  5244 
  5245 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5246 additional print modes to be specified; e.g. "pr(latex)" will print
  5247 proof state according to the Isabelle LaTeX style;
  5248 
  5249 * Isar: improved support for emulating tactic scripts, including proof
  5250 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5251 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5252 (for HOL datatypes);
  5253 
  5254 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5255 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5256 'proof method scripts' have to be in depth-first order;
  5257 
  5258 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5259 
  5260 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5261 should instead use individual commands for printing items
  5262 (print_commands, print_methods etc.);
  5263 
  5264 * Isar: added 'nothing' --- the empty list of theorems;
  5265 
  5266 
  5267 *** HOL ***
  5268 
  5269 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5270 corresponding virtual machine and a specification of its bytecode
  5271 verifier and a lightweight bytecode verifier, including proofs of
  5272 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5273 Cornelia Pusch (see also the homepage of project Bali at
  5274 http://isabelle.in.tum.de/Bali/);
  5275 
  5276 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5277 Clemens Ballarin;
  5278 
  5279 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5280 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5281 Rasmussen;
  5282 
  5283 * HOL/Lattice: fundamental concepts of lattice theory and order
  5284 structures, including duals, properties of bounds versus algebraic
  5285 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5286 Theorem for complete lattices etc.; may also serve as a demonstration
  5287 for abstract algebraic reasoning using axiomatic type classes, and
  5288 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5289 
  5290 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5291 von Oheimb;
  5292 
  5293 * HOL/IMPP: extension of IMP with local variables and mutually
  5294 recursive procedures, by David von Oheimb;
  5295 
  5296 * HOL/Lambda: converted into new-style theory and document;
  5297 
  5298 * HOL/ex/Multiquote: example of multiple nested quotations and
  5299 anti-quotations -- basically a generalized version of de-Bruijn
  5300 representation; very useful in avoiding lifting of operations;
  5301 
  5302 * HOL/record: added general record equality rule to simpset; fixed
  5303 select-update simplification procedure to handle extended records as
  5304 well; admit "r" as field name;
  5305 
  5306 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5307 other numeric types and also as the identity of groups, rings, etc.;
  5308 
  5309 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5310 Types nat and int belong to this axclass;
  5311 
  5312 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5313    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5314    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5315   two terms #m*u and #n*u are replaced by #(m+n)*u
  5316     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5317   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5318     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5319 
  5320 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5321 powerful prover for predicate logic but knows nothing of clasets; see
  5322 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5323 
  5324 * HOL: new version of "case_tac" subsumes both boolean case split and
  5325 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5326 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5327 
  5328 * HOL: simplification no longer dives into case-expressions: only the
  5329 selector expression is simplified, but not the remaining arms; to
  5330 enable full simplification of case-expressions for datatype t, you may
  5331 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5332 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5333 
  5334 * HOL/recdef: the recursion equations generated by 'recdef' for
  5335 function 'f' are now called f.simps instead of f.rules; if all
  5336 termination conditions are proved automatically, these simplification
  5337 rules are added to the simpset, as in primrec; rules may be named
  5338 individually as well, resulting in a separate list of theorems for
  5339 each equation;
  5340 
  5341 * HOL/While is a new theory that provides a while-combinator. It
  5342 permits the definition of tail-recursive functions without the
  5343 provision of a termination measure. The latter is necessary once the
  5344 invariant proof rule for while is applied.
  5345 
  5346 * HOL: new (overloaded) notation for the set of elements below/above
  5347 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5348 
  5349 * HOL: theorems impI, allI, ballI bound as "strip";
  5350 
  5351 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5352 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5353 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5354 
  5355 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5356 
  5357 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5358 main HOL, but was unused);
  5359 
  5360 * HOL: fewer consts declared as global (e.g. have to refer to
  5361 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5362 
  5363 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5364 in case of overlap with user translations (e.g. judgements over
  5365 tuples); (note that the underlying logical represenation is still
  5366 bogus);
  5367 
  5368 
  5369 *** ZF ***
  5370 
  5371 * ZF: simplification automatically cancels common terms in arithmetic
  5372 expressions over nat and int;
  5373 
  5374 * ZF: new treatment of nat to minimize type-checking: all operators
  5375 coerce their operands to a natural number using the function natify,
  5376 making the algebraic laws unconditional;
  5377 
  5378 * ZF: as above, for int: operators coerce their operands to an integer
  5379 using the function intify;
  5380 
  5381 * ZF: the integer library now contains many of the usual laws for the
  5382 orderings, including $<=, and monotonicity laws for $+ and $*;
  5383 
  5384 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5385 simplification;
  5386 
  5387 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5388 to the simplifier and classical reasoner simultaneously;
  5389 
  5390 
  5391 *** General ***
  5392 
  5393 * Provers: blast_tac now handles actual object-logic rules as
  5394 assumptions; note that auto_tac uses blast_tac internally as well;
  5395 
  5396 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5397 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5398 
  5399 * Provers: delrules now handles destruct rules as well (no longer need
  5400 explicit make_elim);
  5401 
  5402 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5403   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5404 use instead the strong form,
  5405   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5406 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5407 from destruct-rules;
  5408 
  5409 * Provers: Simplifier.easy_setup provides a fast path to basic
  5410 Simplifier setup for new object-logics;
  5411 
  5412 * Pure: AST translation rules no longer require constant head on LHS;
  5413 
  5414 * Pure: improved name spaces: ambiguous output is qualified; support
  5415 for hiding of names;
  5416 
  5417 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5418 XSYMBOL_HOME; no longer need to do manual configuration in most
  5419 situations;
  5420 
  5421 * system: compression of ML heaps images may now be controlled via -c
  5422 option of isabelle and isatool usedir (currently only observed by
  5423 Poly/ML);
  5424 
  5425 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5426 useful for remote X11);
  5427 
  5428 * system: provide TAGS file for Isabelle sources;
  5429 
  5430 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5431 order;
  5432 
  5433 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5434 timing flag supersedes proof_timing and Toplevel.trace;
  5435 
  5436 * ML: new combinators |>> and |>>> for incremental transformations
  5437 with secondary results (e.g. certain theory extensions):
  5438 
  5439 * ML: PureThy.add_defs gets additional argument to indicate potential
  5440 overloading (usually false);
  5441 
  5442 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5443 results;
  5444 
  5445 
  5446 
  5447 New in Isabelle99 (October 1999)
  5448 --------------------------------
  5449 
  5450 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5451 
  5452 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5453 are no longer simplified.  (This allows the simplifier to unfold recursive
  5454 functional programs.)  To restore the old behaviour, declare
  5455 
  5456     Delcongs [if_weak_cong];
  5457 
  5458 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5459 complement;
  5460 
  5461 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5462 
  5463 * HOL/datatype: mutual_induct_tac no longer exists --
  5464   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5465 
  5466 * HOL/typedef: fixed type inference for representing set; type
  5467 arguments now have to occur explicitly on the rhs as type constraints;
  5468 
  5469 * ZF: The con_defs part of an inductive definition may no longer refer
  5470 to constants declared in the same theory;
  5471 
  5472 * HOL, ZF: the function mk_cases, generated by the inductive
  5473 definition package, has lost an argument.  To simplify its result, it
  5474 uses the default simpset instead of a supplied list of theorems.
  5475 
  5476 * HOL/List: the constructors of type list are now Nil and Cons;
  5477 
  5478 * Simplifier: the type of the infix ML functions
  5479         setSSolver addSSolver setSolver addSolver
  5480 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5481 for packaging solvers. A solver is created via
  5482         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5483 where the string argument is only a comment.
  5484 
  5485 
  5486 *** Proof tools ***
  5487 
  5488 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5489 decision procedure for linear arithmetic. Currently it is used for
  5490 types `nat', `int', and `real' in HOL (see below); it can, should and
  5491 will be instantiated for other types and logics as well.
  5492 
  5493 * The simplifier now accepts rewrite rules with flexible heads, eg
  5494      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5495   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5496   matching.
  5497 
  5498 
  5499 *** General ***
  5500 
  5501 * New Isabelle/Isar subsystem provides an alternative to traditional
  5502 tactical theorem proving; together with the ProofGeneral/isar user
  5503 interface it offers an interactive environment for developing human
  5504 readable proof documents (Isar == Intelligible semi-automated
  5505 reasoning); for further information see isatool doc isar-ref,
  5506 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5507 
  5508 * improved and simplified presentation of theories: better HTML markup
  5509 (including colors), graph views in several sizes; isatool usedir now
  5510 provides a proper interface for user theories (via -P option); actual
  5511 document preparation based on (PDF)LaTeX is available as well (for
  5512 new-style theories only); see isatool doc system for more information;
  5513 
  5514 * native support for Proof General, both for classic Isabelle and
  5515 Isabelle/Isar;
  5516 
  5517 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5518 using the graph browser tool;
  5519 
  5520 * Isabelle manuals now also available as PDF;
  5521 
  5522 * theory loader rewritten from scratch (may not be fully
  5523 bug-compatible); old loadpath variable has been replaced by show_path,
  5524 add_path, del_path, reset_path functions; new operations such as
  5525 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5526 isatool doc ref);
  5527 
  5528 * improved isatool install: option -k creates KDE application icon,
  5529 option -p DIR installs standalone binaries;
  5530 
  5531 * added ML_PLATFORM setting (useful for cross-platform installations);
  5532 more robust handling of platform specific ML images for SML/NJ;
  5533 
  5534 * the settings environment is now statically scoped, i.e. it is never
  5535 created again in sub-processes invoked from isabelle, isatool, or
  5536 Isabelle;
  5537 
  5538 * path element specification '~~' refers to '$ISABELLE_HOME';
  5539 
  5540 * in locales, the "assumes" and "defines" parts may be omitted if
  5541 empty;
  5542 
  5543 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5544 long arrows);
  5545 
  5546 * new print_mode "HTML";
  5547 
  5548 * new flag show_tags controls display of tags of theorems (which are
  5549 basically just comments that may be attached by some tools);
  5550 
  5551 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5552 mode and goal output format:
  5553 
  5554 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5555 244c244
  5556 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5557 ---
  5558 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5559 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5560 181c181
  5561 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5562 ---
  5563 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5564 
  5565 * function bind_thms stores lists of theorems (cf. bind_thm);
  5566 
  5567 * new shorthand tactics ftac, eatac, datac, fatac;
  5568 
  5569 * qed (and friends) now accept "" as result name; in that case the
  5570 theorem is not stored, but proper checks and presentation of the
  5571 result still apply;
  5572 
  5573 * theorem database now also indexes constants "Trueprop", "all",
  5574 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5575 
  5576 
  5577 *** HOL ***
  5578 
  5579 ** HOL arithmetic **
  5580 
  5581 * There are now decision procedures for linear arithmetic over nat and
  5582 int:
  5583 
  5584 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5585 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5586 are treated as atomic; subformulae not involving type `nat' or `int'
  5587 are ignored; quantified subformulae are ignored unless they are
  5588 positive universal or negative existential. The tactic has to be
  5589 invoked by hand and can be a little bit slow. In particular, the
  5590 running time is exponential in the number of occurrences of `min' and
  5591 `max', and `-' on `nat'.
  5592 
  5593 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5594 (negated) (in)equalities among the premises and the conclusion into
  5595 account (i.e. no compound formulae) and does not know about `min' and
  5596 `max', and `-' on `nat'. It is fast and is used automatically by the
  5597 simplifier.
  5598 
  5599 NB: At the moment, these decision procedures do not cope with mixed
  5600 nat/int formulae where the two parts interact, such as `m < n ==>
  5601 int(m) < int(n)'.
  5602 
  5603 * HOL/Numeral provides a generic theory of numerals (encoded
  5604 efficiently as bit strings); setup for types nat/int/real is in place;
  5605 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5606 int, existing theories and proof scripts may require a few additional
  5607 type constraints;
  5608 
  5609 * integer division and remainder can now be performed on constant
  5610 arguments;
  5611 
  5612 * many properties of integer multiplication, division and remainder
  5613 are now available;
  5614 
  5615 * An interface to the Stanford Validity Checker (SVC) is available through the
  5616 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5617 are proved automatically.  SVC must be installed separately, and its results
  5618 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5619 invocation of the underlying oracle).  For SVC see
  5620   http://verify.stanford.edu/SVC
  5621 
  5622 * IsaMakefile: the HOL-Real target now builds an actual image;
  5623 
  5624 
  5625 ** HOL misc **
  5626 
  5627 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5628 (in Isabelle/Isar) -- by Gertrud Bauer;
  5629 
  5630 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5631 analysis for assembly languages with subtypes;
  5632 
  5633 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5634 -- avoids syntactic ambiguities and treats state, transition, and
  5635 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5636 changed syntax and (many) tactics;
  5637 
  5638 * HOL/inductive: Now also handles more general introduction rules such
  5639   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5640   theorems are now maintained within the theory (maintained via the
  5641   "mono" attribute);
  5642 
  5643 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5644   (using function types) such as
  5645 
  5646   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5647 
  5648 * HOL/record: record_simproc (part of the default simpset) takes care
  5649 of selectors applied to updated records; record_split_tac is no longer
  5650 part of the default claset; update_defs may now be removed from the
  5651 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5652 
  5653   claset_ref () := claset() addSWrapper record_split_wrapper;
  5654   Delsimprocs [record_simproc]
  5655 
  5656 * HOL/typedef: fixed type inference for representing set; type
  5657 arguments now have to occur explicitly on the rhs as type constraints;
  5658 
  5659 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5660 names rather than an ML expression;
  5661 
  5662 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5663 supplied later.  Program schemes can be defined, such as
  5664     "While B C s = (if B s then While B C (C s) else s)"
  5665 where the well-founded relation can be chosen after B and C have been given.
  5666 
  5667 * HOL/List: the constructors of type list are now Nil and Cons;
  5668 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5669 course, ML tools referring to List.list.op # etc. have to be adapted;
  5670 
  5671 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5672 disabled by default; run isabelle with option -m HOL to get back to
  5673 the original Gordon/HOL-style output;
  5674 
  5675 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5676 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5677 
  5678 * HOL basic syntax simplified (more orthogonal): all variants of
  5679 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5680 Eps operator is provided as well: "SOME x. P[x]";
  5681 
  5682 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5683 
  5684 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5685 thus available for user theories;
  5686 
  5687 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5688 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5689 time;
  5690 
  5691 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5692 several times and then mp;
  5693 
  5694 
  5695 *** LK ***
  5696 
  5697 * the notation <<...>> is now available as a notation for sequences of
  5698 formulas;
  5699 
  5700 * the simplifier is now installed
  5701 
  5702 * the axiom system has been generalized (thanks to Soren Heilmann)
  5703 
  5704 * the classical reasoner now has a default rule database
  5705 
  5706 
  5707 *** ZF ***
  5708 
  5709 * new primrec section allows primitive recursive functions to be given
  5710 directly (as in HOL) over datatypes and the natural numbers;
  5711 
  5712 * new tactics induct_tac and exhaust_tac for induction (or case
  5713 analysis) over datatypes and the natural numbers;
  5714 
  5715 * the datatype declaration of type T now defines the recursor T_rec;
  5716 
  5717 * simplification automatically does freeness reasoning for datatype
  5718 constructors;
  5719 
  5720 * automatic type-inference, with AddTCs command to insert new
  5721 type-checking rules;
  5722 
  5723 * datatype introduction rules are now added as Safe Introduction rules
  5724 to the claset;
  5725 
  5726 * the syntax "if P then x else y" is now available in addition to
  5727 if(P,x,y);
  5728 
  5729 
  5730 *** Internal programming interfaces ***
  5731 
  5732 * tuned simplifier trace output; new flag debug_simp;
  5733 
  5734 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5735 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5736 
  5737 * AxClass.axclass_tac lost the theory argument;
  5738 
  5739 * tuned current_goals_markers semantics: begin / end goal avoids
  5740 printing empty lines;
  5741 
  5742 * removed prs and prs_fn hook, which was broken because it did not
  5743 include \n in its semantics, forcing writeln to add one
  5744 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5745 string -> unit if you really want to output text without newline;
  5746 
  5747 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5748 plain output, interface builders may have to enable 'isabelle_font'
  5749 mode to get Isabelle font glyphs as before;
  5750 
  5751 * refined token_translation interface; INCOMPATIBILITY: output length
  5752 now of type real instead of int;
  5753 
  5754 * theory loader actions may be traced via new ThyInfo.add_hook
  5755 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5756 your own database of information attached to *whole* theories -- as
  5757 opposed to intra-theory data slots offered via TheoryDataFun;
  5758 
  5759 * proper handling of dangling sort hypotheses (at last!);
  5760 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5761 extra sort hypotheses that can be witnessed from the type signature;
  5762 the force_strip_shyps flag is gone, any remaining shyps are simply
  5763 left in the theorem (with a warning issued by strip_shyps_warning);
  5764 
  5765 
  5766 
  5767 New in Isabelle98-1 (October 1998)
  5768 ----------------------------------
  5769 
  5770 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5771 
  5772 * several changes of automated proof tools;
  5773 
  5774 * HOL: major changes to the inductive and datatype packages, including
  5775 some minor incompatibilities of theory syntax;
  5776 
  5777 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5778 called `inj_on';
  5779 
  5780 * HOL: removed duplicate thms in Arith:
  5781   less_imp_add_less  should be replaced by  trans_less_add1
  5782   le_imp_add_le      should be replaced by  trans_le_add1
  5783 
  5784 * HOL: unary minus is now overloaded (new type constraints may be
  5785 required);
  5786 
  5787 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5788 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5789 now taken as an integer constant.
  5790 
  5791 * Pure: ML function 'theory_of' renamed to 'theory';
  5792 
  5793 
  5794 *** Proof tools ***
  5795 
  5796 * Simplifier:
  5797   1. Asm_full_simp_tac is now more aggressive.
  5798      1. It will sometimes reorient premises if that increases their power to
  5799         simplify.
  5800      2. It does no longer proceed strictly from left to right but may also
  5801         rotate premises to achieve further simplification.
  5802      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5803      old Asm_full_simp_tac in that it does not rotate premises.
  5804   2. The simplifier now knows a little bit about nat-arithmetic.
  5805 
  5806 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5807 allows for selected deletion of wrappers, by introduction of names for
  5808 wrapper functionals.  This implies that addbefore, addSbefore,
  5809 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5810 and that adding two tactics with the same name overwrites the first
  5811 one (emitting a warning).
  5812   type wrapper = (int -> tactic) -> (int -> tactic)
  5813   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5814   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5815   delWrapper, delSWrapper: claset *  string            -> claset
  5816   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5817 
  5818 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5819 semantics; addbefore now affects only the unsafe part of step_tac
  5820 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5821 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5822 by Force_tac;
  5823 
  5824 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5825 compWrapper; added safe wrapper (and access functions for it);
  5826 
  5827 * HOL/split_all_tac is now much faster and fails if there is nothing
  5828 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5829 and the names of the automatically generated variables have changed.
  5830 split_all_tac has moved within claset() from unsafe wrappers to safe
  5831 wrappers, which means that !!-bound variables are split much more
  5832 aggressively, and safe_tac and clarify_tac now split such variables.
  5833 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5834 Note: the same holds for record_split_tac, which does the job of
  5835 split_all_tac for record fields.
  5836 
  5837 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5838 permanently to the default simpset using Addsplits just like
  5839 Addsimps. They can be removed via Delsplits just like
  5840 Delsimps. Lower-case versions are also available.
  5841 
  5842 * HOL/Simplifier: The rule split_if is now part of the default
  5843 simpset. This means that the simplifier will eliminate all occurrences
  5844 of if-then-else in the conclusion of a goal. To prevent this, you can
  5845 either remove split_if completely from the default simpset by
  5846 `Delsplits [split_if]' or remove it in a specific call of the
  5847 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5848 other case splitting rules to/from the default simpset: every datatype
  5849 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5850 t is the name of the datatype).
  5851 
  5852 * Classical reasoner / Simplifier combination: new force_tac (and
  5853 derivatives Force_tac, force) combines rewriting and classical
  5854 reasoning (and whatever other tools) similarly to auto_tac, but is
  5855 aimed to solve the given subgoal completely.
  5856 
  5857 
  5858 *** General ***
  5859 
  5860 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5861 and `goalw': the theory is no longer needed as an explicit argument -
  5862 the current theory context is used; assumptions are no longer returned
  5863 at the ML-level unless one of them starts with ==> or !!; it is
  5864 recommended to convert to these new commands using isatool fixgoal
  5865 (backup your sources first!);
  5866 
  5867 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5868 the current theory context, and 'theory' to lookup stored theories;
  5869 
  5870 * new theory section 'locale' for declaring constants, assumptions and
  5871 definitions that have local scope;
  5872 
  5873 * new theory section 'nonterminals' for purely syntactic types;
  5874 
  5875 * new theory section 'setup' for generic ML setup functions
  5876 (e.g. package initialization);
  5877 
  5878 * the distribution now includes Isabelle icons: see
  5879 lib/logo/isabelle-{small,tiny}.xpm;
  5880 
  5881 * isatool install - install binaries with absolute references to
  5882 ISABELLE_HOME/bin;
  5883 
  5884 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5885 
  5886 * print mode 'emacs' reserved for Isamode;
  5887 
  5888 * support multiple print (ast) translations per constant name;
  5889 
  5890 * theorems involving oracles are now printed with a suffixed [!];
  5891 
  5892 
  5893 *** HOL ***
  5894 
  5895 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5896 
  5897 * HOL/inductive package reorganized and improved: now supports mutual
  5898 definitions such as
  5899 
  5900   inductive EVEN ODD
  5901     intrs
  5902       null "0 : EVEN"
  5903       oddI "n : EVEN ==> Suc n : ODD"
  5904       evenI "n : ODD ==> Suc n : EVEN"
  5905 
  5906 new theorem list "elims" contains an elimination rule for each of the
  5907 recursive sets; inductive definitions now handle disjunctive premises
  5908 correctly (also ZF);
  5909 
  5910 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5911 "mutual_induct" no longer exists - the induction rule is always
  5912 contained in "induct";
  5913 
  5914 
  5915 * HOL/datatype package re-implemented and greatly improved: now
  5916 supports mutually recursive datatypes such as
  5917 
  5918   datatype
  5919     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5920             | SUM ('a aexp) ('a aexp)
  5921             | DIFF ('a aexp) ('a aexp)
  5922             | NUM 'a
  5923   and
  5924     'a bexp = LESS ('a aexp) ('a aexp)
  5925             | AND ('a bexp) ('a bexp)
  5926             | OR ('a bexp) ('a bexp)
  5927 
  5928 as well as indirectly recursive datatypes such as
  5929 
  5930   datatype
  5931     ('a, 'b) term = Var 'a
  5932                   | App 'b ((('a, 'b) term) list)
  5933 
  5934 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5935 induction on mutually / indirectly recursive datatypes.
  5936 
  5937 Primrec equations are now stored in theory and can be accessed via
  5938 <function_name>.simps.
  5939 
  5940 INCOMPATIBILITIES:
  5941 
  5942   - Theories using datatypes must now have theory Datatype as an
  5943     ancestor.
  5944   - The specific <typename>.induct_tac no longer exists - use the
  5945     generic induct_tac instead.
  5946   - natE has been renamed to nat.exhaust - use exhaust_tac
  5947     instead of res_inst_tac ... natE. Note that the variable
  5948     names in nat.exhaust differ from the names in natE, this
  5949     may cause some "fragile" proofs to fail.
  5950   - The theorems split_<typename>_case and split_<typename>_case_asm
  5951     have been renamed to <typename>.split and <typename>.split_asm.
  5952   - Since default sorts of type variables are now handled correctly,
  5953     some datatype definitions may have to be annotated with explicit
  5954     sort constraints.
  5955   - Primrec definitions no longer require function name and type
  5956     of recursive argument.
  5957 
  5958 Consider using isatool fixdatatype to adapt your theories and proof
  5959 scripts to the new package (backup your sources first!).
  5960 
  5961 
  5962 * HOL/record package: considerably improved implementation; now
  5963 includes concrete syntax for record types, terms, updates; theorems
  5964 for surjective pairing and splitting !!-bound record variables; proof
  5965 support is as follows:
  5966 
  5967   1) standard conversions (selectors or updates applied to record
  5968 constructor terms) are part of the standard simpset;
  5969 
  5970   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5971 made part of standard simpset and claset via addIffs;
  5972 
  5973   3) a tactic for record field splitting (record_split_tac) is part of
  5974 the standard claset (addSWrapper);
  5975 
  5976 To get a better idea about these rules you may retrieve them via
  5977 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5978 the name of your record type.
  5979 
  5980 The split tactic 3) conceptually simplifies by the following rule:
  5981 
  5982   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5983 
  5984 Thus any record variable that is bound by meta-all will automatically
  5985 blow up into some record constructor term, consequently the
  5986 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5987 solve record problems automatically.
  5988 
  5989 
  5990 * reorganized the main HOL image: HOL/Integ and String loaded by
  5991 default; theory Main includes everything;
  5992 
  5993 * automatic simplification of integer sums and comparisons, using cancellation;
  5994 
  5995 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5996 
  5997 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5998 
  5999 * many new identities for unions, intersections, set difference, etc.;
  6000 
  6001 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  6002 called split_if, split_split, split_sum_case and split_nat_case (to go
  6003 with add/delsplits);
  6004 
  6005 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  6006 (?x::unit) = (); this is made part of the default simpset, which COULD
  6007 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  6008 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  6009 unit_abs_eta_conv is added in order to counter the effect of
  6010 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  6011 %u.f();
  6012 
  6013 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  6014 makes more sense);
  6015 
  6016 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6017   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6018   disjointness reasoning but breaking a few old proofs.
  6019 
  6020 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  6021 to 'converse' from 'inverse' (for compatibility with ZF and some
  6022 literature);
  6023 
  6024 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  6025 the well-founded relation;
  6026 
  6027 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  6028     Compl A.  The "Compl" syntax remains available as input syntax for this
  6029     release ONLY.
  6030 
  6031 * HOL/Update: new theory of function updates:
  6032     f(a:=b) == %x. if x=a then b else f x
  6033 may also be iterated as in f(a:=b,c:=d,...);
  6034 
  6035 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  6036 
  6037 * HOL/List:
  6038   - new function list_update written xs[i:=v] that updates the i-th
  6039     list position. May also be iterated as in xs[i:=a,j:=b,...].
  6040   - new function `upt' written [i..j(] which generates the list
  6041     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  6042     bound write [i..j], which is a shorthand for [i..j+1(].
  6043   - new lexicographic orderings and corresponding wellfoundedness theorems.
  6044 
  6045 * HOL/Arith:
  6046   - removed 'pred' (predecessor) function;
  6047   - generalized some theorems about n-1;
  6048   - many new laws about "div" and "mod";
  6049   - new laws about greatest common divisors (see theory ex/Primes);
  6050 
  6051 * HOL/Relation: renamed the relational operator r^-1 "converse"
  6052 instead of "inverse";
  6053 
  6054 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  6055   of the multiset ordering;
  6056 
  6057 * directory HOL/Real: a construction of the reals using Dedekind cuts
  6058   (not included by default);
  6059 
  6060 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  6061 
  6062 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  6063   programs, i.e. different program variables may have different types.
  6064 
  6065 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6066   [previously, this check worked only if the rewrite rule was unconditional]
  6067   Now rew can involve either definitions or equalities (either == or =).
  6068 
  6069 
  6070 *** ZF ***
  6071 
  6072 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  6073   only the theorems proved on ZF.ML;
  6074 
  6075 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6076   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6077   disjointness reasoning but breaking a few old proofs.
  6078 
  6079 * ZF/Update: new theory of function updates
  6080     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  6081   may also be iterated as in f(a:=b,c:=d,...);
  6082 
  6083 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6084 
  6085 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6086   [previously, this check worked only if the rewrite rule was unconditional]
  6087   Now rew can involve either definitions or equalities (either == or =).
  6088 
  6089 * case_tac provided for compatibility with HOL
  6090     (like the old excluded_middle_tac, but with subgoals swapped)
  6091 
  6092 
  6093 *** Internal programming interfaces ***
  6094 
  6095 * Pure: several new basic modules made available for general use, see
  6096 also src/Pure/README;
  6097 
  6098 * improved the theory data mechanism to support encapsulation (data
  6099 kind name replaced by private Object.kind, acting as authorization
  6100 key); new type-safe user interface via functor TheoryDataFun; generic
  6101 print_data function becomes basically useless;
  6102 
  6103 * removed global_names compatibility flag -- all theory declarations
  6104 are qualified by default;
  6105 
  6106 * module Pure/Syntax now offers quote / antiquote translation
  6107 functions (useful for Hoare logic etc. with implicit dependencies);
  6108 see HOL/ex/Antiquote for an example use;
  6109 
  6110 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  6111 cterm -> thm;
  6112 
  6113 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  6114 subgoal;
  6115 
  6116 * Display.print_goals function moved to Locale.print_goals;
  6117 
  6118 * standard print function for goals supports current_goals_markers
  6119 variable for marking begin of proof, end of proof, start of goal; the
  6120 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  6121 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  6122 for example;
  6123 
  6124 
  6125 
  6126 New in Isabelle98 (January 1998)
  6127 --------------------------------
  6128 
  6129 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6130 
  6131 * changed lexical syntax of terms / types: dots made part of long
  6132 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6133 
  6134 * simpset (and claset) reference variable replaced by functions
  6135 simpset / simpset_ref;
  6136 
  6137 * no longer supports theory aliases (via merge) and non-trivial
  6138 implicit merge of thms' signatures;
  6139 
  6140 * most internal names of constants changed due to qualified names;
  6141 
  6142 * changed Pure/Sequence interface (see Pure/seq.ML);
  6143 
  6144 
  6145 *** General Changes ***
  6146 
  6147 * hierachically structured name spaces (for consts, types, axms, thms
  6148 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6149 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6150 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6151 long_names for fully qualified output names; NOTE: ML programs
  6152 (special tactics, packages etc.) referring to internal names may have
  6153 to be adapted to cope with fully qualified names; in case of severe
  6154 backward campatibility problems try setting 'global_names' at compile
  6155 time to have enrything declared within a flat name space; one may also
  6156 fine tune name declarations in theories via the 'global' and 'local'
  6157 section;
  6158 
  6159 * reimplemented the implicit simpset and claset using the new anytype
  6160 data filed in signatures; references simpset:simpset ref etc. are
  6161 replaced by functions simpset:unit->simpset and
  6162 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6163 to patch your ML files accordingly;
  6164 
  6165 * HTML output now includes theory graph data for display with Java
  6166 applet or isatool browser; data generated automatically via isatool
  6167 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6168 
  6169 * defs may now be conditional; improved rewrite_goals_tac to handle
  6170 conditional equations;
  6171 
  6172 * defs now admits additional type arguments, using TYPE('a) syntax;
  6173 
  6174 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6175 creates a new theory node; implicit merge of thms' signatures is
  6176 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6177 transfer:theory->thm->thm in (rare) cases;
  6178 
  6179 * improved handling of draft signatures / theories; draft thms (and
  6180 ctyps, cterms) are automatically promoted to real ones;
  6181 
  6182 * slightly changed interfaces for oracles: admit many per theory, named
  6183 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6184 
  6185 * print_goals: optional output of const types (set show_consts and
  6186 show_types);
  6187 
  6188 * improved output of warnings (###) and errors (***);
  6189 
  6190 * subgoal_tac displays a warning if the new subgoal has type variables;
  6191 
  6192 * removed old README and Makefiles;
  6193 
  6194 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6195 
  6196 * removed obsolete init_pps and init_database;
  6197 
  6198 * deleted the obsolete tactical STATE, which was declared by
  6199     fun STATE tacfun st = tacfun st st;
  6200 
  6201 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6202 (which abbreviates $HOME);
  6203 
  6204 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6205 use isatool fixseq to adapt your ML programs (this works for fully
  6206 qualified references to the Sequence structure only!);
  6207 
  6208 * use_thy no longer requires writable current directory; it always
  6209 reloads .ML *and* .thy file, if either one is out of date;
  6210 
  6211 
  6212 *** Classical Reasoner ***
  6213 
  6214 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6215 tactics that use classical reasoning to simplify a subgoal without
  6216 splitting it into several subgoals;
  6217 
  6218 * Safe_tac: like safe_tac but uses the default claset;
  6219 
  6220 
  6221 *** Simplifier ***
  6222 
  6223 * added simplification meta rules:
  6224     (asm_)(full_)simplify: simpset -> thm -> thm;
  6225 
  6226 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6227 logics (again);
  6228 
  6229 * added prems argument to simplification procedures;
  6230 
  6231 * HOL, FOL, ZF: added infix function `addsplits':
  6232   instead of `<simpset> setloop (split_tac <thms>)'
  6233   you can simply write `<simpset> addsplits <thms>'
  6234 
  6235 
  6236 *** Syntax ***
  6237 
  6238 * TYPE('a) syntax for type reflection terms;
  6239 
  6240 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6241 
  6242 * pretty printer: changed order of mixfix annotation preference (again!);
  6243 
  6244 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6245 
  6246