NEWS
author wenzelm
Mon Nov 23 22:47:08 2009 +0100 (2009-11-23)
changeset 33873 e9120a7b2779
parent 33860 dcd9affbd106
child 33951 651028e34b5d
child 33993 f412388c809c
permissions -rw-r--r--
more tuning for release;
     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 theories Divides
   118     and GCD as well as in new session Number_Theory
   119   - some constants and facts now suffixed with _nat and _int
   120     accordingly
   121   - former session NumberTheory now named Old_Number_Theory, including
   122     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   123   - moved theory Pocklington from src/HOL/Library to
   124     src/HOL/Old_Number_Theory
   125 
   126 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   127 lcm of finite and infinite sets. It is shown that they form a complete
   128 lattice.
   129 
   130 * Class semiring_div requires superclass no_zero_divisors and proof of
   131 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   132 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   133 generalized to class semiring_div, subsuming former theorems
   134 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   135 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   136 INCOMPATIBILITY.
   137 
   138 * Refinements to lattice classes and sets:
   139   - less default intro/elim rules in locale variant, more default
   140     intro/elim rules in class variant: more uniformity
   141   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   142     le_inf_iff
   143   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   144     sup_aci)
   145   - renamed ACI to inf_sup_aci
   146   - new class "boolean_algebra"
   147   - class "complete_lattice" moved to separate theory
   148     "Complete_Lattice"; corresponding constants (and abbreviations)
   149     renamed and with authentic syntax:
   150     Set.Inf ~>    Complete_Lattice.Inf
   151     Set.Sup ~>    Complete_Lattice.Sup
   152     Set.INFI ~>   Complete_Lattice.INFI
   153     Set.SUPR ~>   Complete_Lattice.SUPR
   154     Set.Inter ~>  Complete_Lattice.Inter
   155     Set.Union ~>  Complete_Lattice.Union
   156     Set.INTER ~>  Complete_Lattice.INTER
   157     Set.UNION ~>  Complete_Lattice.UNION
   158   - authentic syntax for
   159     Set.Pow
   160     Set.image
   161   - mere abbreviations:
   162     Set.empty               (for bot)
   163     Set.UNIV                (for top)
   164     Set.inter               (for inf, formerly Set.Int)
   165     Set.union               (for sup, formerly Set.Un)
   166     Complete_Lattice.Inter  (for Inf)
   167     Complete_Lattice.Union  (for Sup)
   168     Complete_Lattice.INTER  (for INFI)
   169     Complete_Lattice.UNION  (for SUPR)
   170   - object-logic definitions as far as appropriate
   171 
   172 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   173 Un_subset_iff are explicitly deleted as default simp rules; then also
   174 their lattice counterparts le_inf_iff and le_sup_iff have to be
   175 deleted to achieve the desired effect.
   176 
   177 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   178 rules by default any longer; the same applies to min_max.inf_absorb1
   179 etc.  INCOMPATIBILITY.
   180 
   181 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   182 pred_set_conv by default.  INCOMPATIBILITY.
   183 
   184 * Power operations on relations and functions are now one dedicated
   185 constant "compow" with infix syntax "^^".  Power operation on
   186 multiplicative monoids retains syntax "^" and is now defined generic
   187 in class power.  INCOMPATIBILITY.
   188 
   189 * Relation composition "R O S" now has a more standard argument order:
   190 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   191 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   192 break, since the O_assoc rule was not rewritten like this.  Fix using
   193 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   194 
   195 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   196 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   197 INCOMPATIBILITY.
   198 
   199 * Most rules produced by inductive and datatype package have mandatory
   200 prefixes.  INCOMPATIBILITY.
   201 
   202 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   203 the attribute of the same name.  Each of the theorems in the list
   204 DERIV_intros assumes composition with an additional function and
   205 matches a variable to the derivative, which has to be solved by the
   206 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   207 of most elementary terms.  Former Maclauren.DERIV_tac and
   208 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   209 INCOMPATIBILITY.
   210 
   211 * Code generator attributes follow the usual underscore convention:
   212     code_unfold     replaces    code unfold
   213     code_post       replaces    code post
   214     etc.
   215   INCOMPATIBILITY.
   216 
   217 * Renamed methods:
   218     sizechange -> size_change
   219     induct_scheme -> induction_schema
   220   INCOMPATIBILITY.
   221 
   222 * Discontinued abbreviation "arbitrary" of constant "undefined".
   223 INCOMPATIBILITY, use "undefined" directly.
   224 
   225 * Renamed theorems:
   226     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   227     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   228     Suc_plus1 -> Suc_eq_plus1
   229     *anti_sym -> *antisym*
   230     vector_less_eq_def -> vector_le_def
   231   INCOMPATIBILITY.
   232 
   233 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   234 INCOMPATIBILITY.
   235 
   236 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   237 INCOMPATIBILITY.
   238 
   239 
   240 *** HOLCF ***
   241 
   242 * Theory Representable defines a class "rep" of domains that are
   243 representable (via an ep-pair) in the universal domain type "udom".
   244 Instances are provided for all type constructors defined in HOLCF.
   245 
   246 * The 'new_domain' command is a purely definitional version of the
   247 domain package, for representable domains.  Syntax is identical to the
   248 old domain package.  The 'new_domain' package also supports indirect
   249 recursion using previously-defined type constructors.  See
   250 src/HOLCF/ex/New_Domain.thy for examples.
   251 
   252 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   253 on the left-hand side of an equation, and then performs
   254 simplification.  Rewriting is done using rules declared with the
   255 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   256 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   257 
   258 * The pattern-match compiler in 'fixrec' can now handle constructors
   259 with HOL function types.  Pattern-match combinators for the Pair
   260 constructor are pre-configured.
   261 
   262 * The 'fixrec' package now produces better fixed-point induction rules
   263 for mutually-recursive definitions:  Induction rules have conclusions
   264 of the form "P foo bar" instead of "P <foo, bar>".
   265 
   266 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   267 been renamed to "below".  The name "below" now replaces "less" in many
   268 theorem names.  (Legacy theorem names using "less" are still supported
   269 as well.)
   270 
   271 * The 'fixrec' package now supports "bottom patterns".  Bottom
   272 patterns can be used to generate strictness rules, or to make
   273 functions more strict (much like the bang-patterns supported by the
   274 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   275 examples.
   276 
   277 
   278 *** ML ***
   279 
   280 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   281 errors and run-time exceptions, including detailed source positions.
   282 
   283 * Structure Name_Space (formerly NameSpace) now manages uniquely
   284 identified entries, with some additional information such as source
   285 position, logical grouping etc.
   286 
   287 * Theory and context data is now introduced by the simplified and
   288 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   289 to be pure, but the old TheoryDataFun for mutable data (with explicit
   290 copy operation) is still available for some time.
   291 
   292 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   293 provides a high-level programming interface to synchronized state
   294 variables with atomic update.  This works via pure function
   295 application within a critical section -- its runtime should be as
   296 short as possible; beware of deadlocks if critical code is nested,
   297 either directly or indirectly via other synchronized variables!
   298 
   299 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   300 wraps raw ML references, explicitly indicating their non-thread-safe
   301 behaviour.  The Isar toplevel keeps this structure open, to
   302 accommodate Proof General as well as quick and dirty interactive
   303 experiments with references.
   304 
   305 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   306 parallel tactical reasoning.
   307 
   308 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   309 are similar to SUBPROOF, but are slightly more flexible: only the
   310 specified parts of the subgoal are imported into the context, and the
   311 body tactic may introduce new subgoals and schematic variables.
   312 
   313 * Old tactical METAHYPS, which does not observe the proof context, has
   314 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   315 or Subgoal.FOCUS etc.
   316 
   317 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   318 functors have their own ML name space there is no point to mark them
   319 separately.)  Minor INCOMPATIBILITY.
   320 
   321 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   322 
   323 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   324 INCOMPATIBILITY.
   325 
   326 * Operations of structure Skip_Proof no longer require quick_and_dirty
   327 mode, which avoids critical setmp.
   328 
   329 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   330 combinators for "args".  INCOMPATIBILITY, need to use simplified
   331 Attrib/Method.setup introduced in Isabelle2009.
   332 
   333 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   334 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   335 last resort.  INCOMPATIBILITY.
   336 
   337 * Display.pretty_thm now requires a proper context (cf. former
   338 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   339 or even Display.pretty_thm_without_context as last resort.
   340 INCOMPATIBILITY.
   341 
   342 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   343 Syntax.pretty_typ/term directly, preferably with proper context
   344 instead of global theory.
   345 
   346 
   347 *** System ***
   348 
   349 * Further fine tuning of parallel proof checking, scales up to 8 cores
   350 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   351 usedir option -q.
   352 
   353 * Support for additional "Isabelle components" via etc/components, see
   354 also the system manual.
   355 
   356 * The isabelle makeall tool now operates on all components with
   357 IsaMakefile, not just hardwired "logics".
   358 
   359 * Removed "compress" option from isabelle-process and isabelle usedir;
   360 this is always enabled.
   361 
   362 * Discontinued support for Poly/ML 4.x versions.
   363 
   364 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   365 on a given logic image.  This requires the lighttpd webserver and is
   366 currently supported on Linux only.
   367 
   368 
   369 
   370 New in Isabelle2009 (April 2009)
   371 --------------------------------
   372 
   373 *** General ***
   374 
   375 * Simplified main Isabelle executables, with less surprises on
   376 case-insensitive file-systems (such as Mac OS).
   377 
   378   - The main Isabelle tool wrapper is now called "isabelle" instead of
   379     "isatool."
   380 
   381   - The former "isabelle" alias for "isabelle-process" has been
   382     removed (should rarely occur to regular users).
   383 
   384   - The former "isabelle-interface" and its alias "Isabelle" have been
   385     removed (interfaces are now regular Isabelle tools).
   386 
   387 Within scripts and make files, the Isabelle environment variables
   388 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   389 respectively.  (The latter are still available as legacy feature.)
   390 
   391 The old isabelle-interface wrapper could react in confusing ways if
   392 the interface was uninstalled or changed otherwise.  Individual
   393 interface tool configuration is now more explicit, see also the
   394 Isabelle system manual.  In particular, Proof General is now available
   395 via "isabelle emacs".
   396 
   397 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   398 purge installed copies of Isabelle executables and re-run "isabelle
   399 install -p ...", or use symlinks.
   400 
   401 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   402 old ~/isabelle, which was slightly non-standard and apt to cause
   403 surprises on case-insensitive file-systems (such as Mac OS).
   404 
   405 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   406 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   407 care is required when using older releases of Isabelle.  Note that
   408 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   409 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   410 
   411 * Proofs of fully specified statements are run in parallel on
   412 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   413 a regular 4-core machine, if the initial heap space is made reasonably
   414 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   415 
   416 * The main reference manuals ("isar-ref", "implementation", and
   417 "system") have been updated and extended.  Formally checked references
   418 as hyperlinks are now available uniformly.
   419 
   420 
   421 *** Pure ***
   422 
   423 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   424 respects.  The most important changes are listed below.  See the
   425 Tutorial on Locales ("locales" manual) for details.
   426 
   427 - In locale expressions, instantiation replaces renaming.  Parameters
   428 must be declared in a for clause.  To aid compatibility with previous
   429 parameter inheritance, in locale declarations, parameters that are not
   430 'touched' (instantiation position "_" or omitted) are implicitly added
   431 with their syntax at the beginning of the for clause.
   432 
   433 - Syntax from abbreviations and definitions in locales is available in
   434 locale expressions and context elements.  The latter is particularly
   435 useful in locale declarations.
   436 
   437 - More flexible mechanisms to qualify names generated by locale
   438 expressions.  Qualifiers (prefixes) may be specified in locale
   439 expressions, and can be marked as mandatory (syntax: "name!:") or
   440 optional (syntax "name?:").  The default depends for plain "name:"
   441 depends on the situation where a locale expression is used: in
   442 commands 'locale' and 'sublocale' prefixes are optional, in
   443 'interpretation' and 'interpret' prefixes are mandatory.  The old
   444 implicit qualifiers derived from the parameter names of a locale are
   445 no longer generated.
   446 
   447 - Command "sublocale l < e" replaces "interpretation l < e".  The
   448 instantiation clause in "interpretation" and "interpret" (square
   449 brackets) is no longer available.  Use locale expressions.
   450 
   451 - When converting proof scripts, mandatory qualifiers in
   452 'interpretation' and 'interpret' should be retained by default, even
   453 if this is an INCOMPATIBILITY compared to former behavior.  In the
   454 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   455 in locale expressions range over a single locale instance only.
   456 
   457 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   458 In existing theorem specifications replace the includes element by the
   459 respective context elements of the included locale, omitting those
   460 that are already present in the theorem specification.  Multiple
   461 assume elements of a locale should be replaced by a single one
   462 involving the locale predicate.  In the proof body, declarations (most
   463 notably theorems) may be regained by interpreting the respective
   464 locales in the proof context as required (command "interpret").
   465 
   466 If using "includes" in replacement of a target solely because the
   467 parameter types in the theorem are not as general as in the target,
   468 consider declaring a new locale with additional type constraints on
   469 the parameters (context element "constrains").
   470 
   471 - Discontinued "locale (open)".  INCOMPATIBILITY.
   472 
   473 - Locale interpretation commands no longer attempt to simplify goal.
   474 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   475 methods intro_locales and unfold_locales to clarify.
   476 
   477 - Locale interpretation commands no longer accept interpretation
   478 attributes.  INCOMPATIBILITY.
   479 
   480 * Class declaration: so-called "base sort" must not be given in import
   481 list any longer, but is inferred from the specification.  Particularly
   482 in HOL, write
   483 
   484     class foo = ...
   485 
   486 instead of
   487 
   488     class foo = type + ...
   489 
   490 * Class target: global versions of theorems stemming do not carry a
   491 parameter prefix any longer.  INCOMPATIBILITY.
   492 
   493 * Class 'instance' command no longer accepts attached definitions.
   494 INCOMPATIBILITY, use proper 'instantiation' target instead.
   495 
   496 * Recovered hiding of consts, which was accidentally broken in
   497 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   498 makes c inaccessible; consider using ``hide (open) const c'' instead.
   499 
   500 * Slightly more coherent Pure syntax, with updated documentation in
   501 isar-ref manual.  Removed locales meta_term_syntax and
   502 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   503 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   504 directly in regular applications.
   505 
   506 * There is a new syntactic category "float_const" for signed decimal
   507 fractions (e.g. 123.45 or -123.45).
   508 
   509 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   510 interface with 'setup' command instead.
   511 
   512 * Command 'local_setup' is similar to 'setup', but operates on a local
   513 theory context.
   514 
   515 * The 'axiomatization' command now only works within a global theory
   516 context.  INCOMPATIBILITY.
   517 
   518 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   519 hypotheses.  Sorts required in the course of reasoning need to be
   520 covered by the constraints in the initial statement, completed by the
   521 type instance information of the background theory.  Non-trivial sort
   522 hypotheses, which rarely occur in practice, may be specified via
   523 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   524 
   525   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   526 
   527 The result contains an implicit sort hypotheses as before --
   528 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   529 normalization.
   530 
   531 * Generalized Isar history, with support for linear undo, direct state
   532 addressing etc.
   533 
   534 * Changed defaults for unify configuration options:
   535 
   536   unify_trace_bound = 50 (formerly 25)
   537   unify_search_bound = 60 (formerly 30)
   538 
   539 * Different bookkeeping for code equations (INCOMPATIBILITY):
   540 
   541   a) On theory merge, the last set of code equations for a particular
   542      constant is taken (in accordance with the policy applied by other
   543      parts of the code generator framework).
   544 
   545   b) Code equations stemming from explicit declarations (e.g. code
   546      attribute) gain priority over default code equations stemming
   547      from definition, primrec, fun etc.
   548 
   549 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   550 
   551 * Unified theorem tables for both code generators.  Thus [code
   552 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   553 
   554 * Command 'find_consts' searches for constants based on type and name
   555 patterns, e.g.
   556 
   557     find_consts "_ => bool"
   558 
   559 By default, matching is against subtypes, but it may be restricted to
   560 the whole type.  Searching by name is possible.  Multiple queries are
   561 conjunctive and queries may be negated by prefixing them with a
   562 hyphen:
   563 
   564     find_consts strict: "_ => bool" name: "Int" -"int => int"
   565 
   566 * New 'find_theorems' criterion "solves" matches theorems that
   567 directly solve the current goal (modulo higher-order unification).
   568 
   569 * Auto solve feature for main theorem statements: whenever a new goal
   570 is stated, "find_theorems solves" is called; any theorems that could
   571 solve the lemma directly are listed as part of the goal state.
   572 Cf. associated options in Proof General Isabelle settings menu,
   573 enabled by default, with reasonable timeout for pathological cases of
   574 higher-order unification.
   575 
   576 
   577 *** Document preparation ***
   578 
   579 * Antiquotation @{lemma} now imitates a regular terminal proof,
   580 demanding keyword 'by' and supporting the full method expression
   581 syntax just like the Isar command 'by'.
   582 
   583 
   584 *** HOL ***
   585 
   586 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   587 points Main and Complex_Main remain as before.
   588 
   589 * Logic image HOL-Plain provides a minimal HOL with the most important
   590 tools available (inductive, datatype, primrec, ...).  This facilitates
   591 experimentation and tool development.  Note that user applications
   592 (and library theories) should never refer to anything below theory
   593 Main, as before.
   594 
   595 * Logic image HOL-Main stops at theory Main, and thus facilitates
   596 experimentation due to shorter build times.
   597 
   598 * Logic image HOL-NSA contains theories of nonstandard analysis which
   599 were previously part of former HOL-Complex.  Entry point Hyperreal
   600 remains valid, but theories formerly using Complex_Main should now use
   601 new entry point Hypercomplex.
   602 
   603 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   604 Posix processes.  Avoids potentially expensive forking of the ML
   605 process.  New thread-based implementation also works on non-Unix
   606 platforms (Cygwin).  Provers are no longer hardwired, but defined
   607 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   608 commands are covered in the isar-ref manual.
   609 
   610 * Wrapper scripts for remote SystemOnTPTP service allows to use
   611 sledgehammer without local ATP installation (Vampire etc.). Other
   612 provers may be included via suitable ML wrappers, see also
   613 src/HOL/ATP_Linkup.thy.
   614 
   615 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   616 menu.
   617 
   618 * The metis method no longer fails because the theorem is too trivial
   619 (contains the empty clause).
   620 
   621 * The metis method now fails in the usual manner, rather than raising
   622 an exception, if it determines that it cannot prove the theorem.
   623 
   624 * Method "coherent" implements a prover for coherent logic (see also
   625 src/Tools/coherent.ML).
   626 
   627 * Constants "undefined" and "default" replace "arbitrary".  Usually
   628 "undefined" is the right choice to replace "arbitrary", though
   629 logically there is no difference.  INCOMPATIBILITY.
   630 
   631 * Command "value" now integrates different evaluation mechanisms.  The
   632 result of the first successful evaluation mechanism is printed.  In
   633 square brackets a particular named evaluation mechanisms may be
   634 specified (currently, [SML], [code] or [nbe]).  See further
   635 src/HOL/ex/Eval_Examples.thy.
   636 
   637 * Normalization by evaluation now allows non-leftlinear equations.
   638 Declare with attribute [code nbe].
   639 
   640 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   641 as the structured Isar versions "cases" and "induct", cf. the
   642 corresponding "cases" and "induct" attributes.  Mutual induction rules
   643 are now presented as a list of individual projections
   644 (e.g. foo_bar.inducts for types foo and bar); the old format with
   645 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   646 rare situations a different rule is selected --- notably nested tuple
   647 elimination instead of former prod.exhaust: use explicit (case_tac t
   648 rule: prod.exhaust) here.
   649 
   650 * Attributes "cases", "induct", "coinduct" support "del" option.
   651 
   652 * Removed fact "case_split_thm", which duplicates "case_split".
   653 
   654 * The option datatype has been moved to a new theory Option.  Renamed
   655 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   656 
   657 * New predicate "strict_mono" classifies strict functions on partial
   658 orders.  With strict functions on linear orders, reasoning about
   659 (in)equalities is facilitated by theorems "strict_mono_eq",
   660 "strict_mono_less_eq" and "strict_mono_less".
   661 
   662 * Some set operations are now proper qualified constants with
   663 authentic syntax.  INCOMPATIBILITY:
   664 
   665     op Int ~>   Set.Int
   666     op Un ~>    Set.Un
   667     INTER ~>    Set.INTER
   668     UNION ~>    Set.UNION
   669     Inter ~>    Set.Inter
   670     Union ~>    Set.Union
   671     {} ~>       Set.empty
   672     UNIV ~>     Set.UNIV
   673 
   674 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   675 theory Set.
   676 
   677 * Auxiliary class "itself" has disappeared -- classes without any
   678 parameter are treated as expected by the 'class' command.
   679 
   680 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   681 
   682 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   683 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   684 
   685 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   686 method "approximation".  It proves formulas on real values by using
   687 interval arithmetic.  In the formulas are also the transcendental
   688 functions sin, cos, tan, atan, ln, exp and the constant pi are
   689 allowed. For examples see
   690 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   691 
   692 * Theory "Reflection" now resides in HOL/Library.
   693 
   694 * Entry point to Word library now simply named "Word".
   695 INCOMPATIBILITY.
   696 
   697 * Made source layout more coherent with logical distribution
   698 structure:
   699 
   700     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   701     src/HOL/Library/Code_Message.thy ~> src/HOL/
   702     src/HOL/Library/GCD.thy ~> src/HOL/
   703     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   704     src/HOL/Library/Parity.thy ~> src/HOL/
   705     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   706     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   707     src/HOL/Real/Lubs.thy ~> src/HOL/
   708     src/HOL/Real/PReal.thy ~> src/HOL/
   709     src/HOL/Real/Rational.thy ~> src/HOL/
   710     src/HOL/Real/RComplete.thy ~> src/HOL/
   711     src/HOL/Real/RealDef.thy ~> src/HOL/
   712     src/HOL/Real/RealPow.thy ~> src/HOL/
   713     src/HOL/Real/Real.thy ~> src/HOL/
   714     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   715     src/HOL/Complex/Complex.thy ~> src/HOL/
   716     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   717     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   718     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   719     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   720     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   721     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   722     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   723     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   724     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   725     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   726     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   727     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   728     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   729     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   730     src/HOL/Real/Float ~> src/HOL/Library/
   731     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   732     src/HOL/Real/RealVector.thy ~> src/HOL/
   733 
   734     src/HOL/arith_data.ML ~> src/HOL/Tools
   735     src/HOL/hologic.ML ~> src/HOL/Tools
   736     src/HOL/simpdata.ML ~> src/HOL/Tools
   737     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   738     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   739     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   740     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   741     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   742     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   743     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   744 
   745     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   746     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   747     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   748     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   749     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   750     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   751 
   752 * If methods "eval" and "evaluation" encounter a structured proof
   753 state with !!/==>, only the conclusion is evaluated to True (if
   754 possible), avoiding strange error messages.
   755 
   756 * Method "sizechange" automates termination proofs using (a
   757 modification of) the size-change principle.  Requires SAT solver.  See
   758 src/HOL/ex/Termination.thy for examples.
   759 
   760 * Simplifier: simproc for let expressions now unfolds if bound
   761 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   762 
   763 * Method "arith": Linear arithmetic now ignores all inequalities when
   764 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   765 
   766 * New attribute "arith" for facts that should always be used
   767 automatically by arithmetic. It is intended to be used locally in
   768 proofs, e.g.
   769 
   770   assumes [arith]: "x > 0"
   771 
   772 Global usage is discouraged because of possible performance impact.
   773 
   774 * New classes "top" and "bot" with corresponding operations "top" and
   775 "bot" in theory Orderings; instantiation of class "complete_lattice"
   776 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   777 
   778 * Changed definition lemma "less_fun_def" in order to provide an
   779 instance for preorders on functions; use lemma "less_le" instead.
   780 INCOMPATIBILITY.
   781 
   782 * Theory Orderings: class "wellorder" moved here, with explicit
   783 induction rule "less_induct" as assumption.  For instantiation of
   784 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   785 INCOMPATIBILITY.
   786 
   787 * Theory Orderings: added class "preorder" as superclass of "order".
   788 INCOMPATIBILITY: Instantiation proofs for order, linorder
   789 etc. slightly changed.  Some theorems named order_class.* now named
   790 preorder_class.*.
   791 
   792 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   793 "diag" to "Id_on".
   794 
   795 * Theory Finite_Set: added a new fold combinator of type
   796 
   797   ('a => 'b => 'b) => 'b => 'a set => 'b
   798 
   799 Occasionally this is more convenient than the old fold combinator
   800 which is now defined in terms of the new one and renamed to
   801 fold_image.
   802 
   803 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   804 and "ring_simps" have been replaced by "algebra_simps" (which can be
   805 extended with further lemmas!).  At the moment both still exist but
   806 the former will disappear at some point.
   807 
   808 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   809 class recpower.  Type-specific simp rules for various recpower types
   810 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   811 
   812 rat_power_0    -> power_0
   813 rat_power_Suc  -> power_Suc
   814 realpow_0      -> power_0
   815 realpow_Suc    -> power_Suc
   816 complexpow_0   -> power_0
   817 complexpow_Suc -> power_Suc
   818 power_poly_0   -> power_0
   819 power_poly_Suc -> power_Suc
   820 
   821 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   822 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   823 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   824 of lemmas from Divides has been generalized from nat to class
   825 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   826 renames resulting from duplicate elimination:
   827 
   828     dvd_def_mod ~>          dvd_eq_mod_eq_0
   829     zero_dvd_iff ~>         dvd_0_left_iff
   830     dvd_0 ~>                dvd_0_right
   831     DIVISION_BY_ZERO_DIV ~> div_by_0
   832     DIVISION_BY_ZERO_MOD ~> mod_by_0
   833     mult_div ~>             div_mult_self2_is_id
   834     mult_mod ~>             mod_mult_self2_is_0
   835 
   836 * Theory IntDiv: removed many lemmas that are instances of class-based
   837 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   838 rename old lemmas as follows:
   839 
   840 dvd_diff               -> nat_dvd_diff
   841 dvd_zminus_iff         -> dvd_minus_iff
   842 mod_add1_eq            -> mod_add_eq
   843 mod_mult1_eq           -> mod_mult_right_eq
   844 mod_mult1_eq'          -> mod_mult_left_eq
   845 mod_mult_distrib_mod   -> mod_mult_eq
   846 nat_mod_add_left_eq    -> mod_add_left_eq
   847 nat_mod_add_right_eq   -> mod_add_right_eq
   848 nat_mod_div_trivial    -> mod_div_trivial
   849 nat_mod_mod_trivial    -> mod_mod_trivial
   850 zdiv_zadd_self1        -> div_add_self1
   851 zdiv_zadd_self2        -> div_add_self2
   852 zdiv_zmult_self1       -> div_mult_self2_is_id
   853 zdiv_zmult_self2       -> div_mult_self1_is_id
   854 zdvd_triv_left         -> dvd_triv_left
   855 zdvd_triv_right        -> dvd_triv_right
   856 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   857 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   858 zmod_zadd_left_eq      -> mod_add_left_eq
   859 zmod_zadd_right_eq     -> mod_add_right_eq
   860 zmod_zadd_self1        -> mod_add_self1
   861 zmod_zadd_self2        -> mod_add_self2
   862 zmod_zadd1_eq          -> mod_add_eq
   863 zmod_zdiff1_eq         -> mod_diff_eq
   864 zmod_zdvd_zmod         -> mod_mod_cancel
   865 zmod_zmod_cancel       -> mod_mod_cancel
   866 zmod_zmult_self1       -> mod_mult_self2_is_0
   867 zmod_zmult_self2       -> mod_mult_self1_is_0
   868 zmod_1                 -> mod_by_1
   869 zdiv_1                 -> div_by_1
   870 zdvd_abs1              -> abs_dvd_iff
   871 zdvd_abs2              -> dvd_abs_iff
   872 zdvd_refl              -> dvd_refl
   873 zdvd_trans             -> dvd_trans
   874 zdvd_zadd              -> dvd_add
   875 zdvd_zdiff             -> dvd_diff
   876 zdvd_zminus_iff        -> dvd_minus_iff
   877 zdvd_zminus2_iff       -> minus_dvd_iff
   878 zdvd_zmultD            -> dvd_mult_right
   879 zdvd_zmultD2           -> dvd_mult_left
   880 zdvd_zmult_mono        -> mult_dvd_mono
   881 zdvd_0_right           -> dvd_0_right
   882 zdvd_0_left            -> dvd_0_left_iff
   883 zdvd_1_left            -> one_dvd
   884 zminus_dvd_iff         -> minus_dvd_iff
   885 
   886 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   887 
   888 * The real numbers offer decimal input syntax: 12.34 is translated
   889 into 1234/10^2. This translation is not reversed upon output.
   890 
   891 * Theory Library/Polynomial defines an abstract type 'a poly of
   892 univariate polynomials with coefficients of type 'a.  In addition to
   893 the standard ring operations, it also supports div and mod.  Code
   894 generation is also supported, using list-style constructors.
   895 
   896 * Theory Library/Inner_Product defines a class of real_inner for real
   897 inner product spaces, with an overloaded operation inner :: 'a => 'a
   898 => real.  Class real_inner is a subclass of real_normed_vector from
   899 theory RealVector.
   900 
   901 * Theory Library/Product_Vector provides instances for the product
   902 type 'a * 'b of several classes from RealVector and Inner_Product.
   903 Definitions of addition, subtraction, scalar multiplication, norms,
   904 and inner products are included.
   905 
   906 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   907 addition to the field operations, numerals and case syntax are also
   908 supported.
   909 
   910 * Theory Library/Diagonalize provides constructive version of Cantor's
   911 first diagonalization argument.
   912 
   913 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   914 zlcm (for int); carried together from various gcd/lcm developements in
   915 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   916 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   917 may recover tupled syntax as follows:
   918 
   919     hide (open) const gcd
   920     abbreviation gcd where
   921       "gcd == (%(a, b). GCD.gcd a b)"
   922     notation (output)
   923       GCD.gcd ("gcd '(_, _')")
   924 
   925 The same works for lcm, zgcd, zlcm.
   926 
   927 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   928 instantiations for algebraic structures.  Removed some duplicate
   929 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   930 
   931 * ML antiquotation @{code} takes a constant as argument and generates
   932 corresponding code in background and inserts name of the corresponding
   933 resulting ML value/function/datatype constructor binding in place.
   934 All occurrences of @{code} with a single ML block are generated
   935 simultaneously.  Provides a generic and safe interface for
   936 instrumentalizing code generation.  See
   937 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   938 In future you ought to refrain from ad-hoc compiling generated SML
   939 code on the ML toplevel.  Note that (for technical reasons) @{code}
   940 cannot refer to constants for which user-defined serializations are
   941 set.  Refer to the corresponding ML counterpart directly in that
   942 cases.
   943 
   944 * Command 'rep_datatype': instead of theorem names the command now
   945 takes a list of terms denoting the constructors of the type to be
   946 represented as datatype.  The characteristic theorems have to be
   947 proven.  INCOMPATIBILITY.  Also observe that the following theorems
   948 have disappeared in favour of existing ones:
   949 
   950     unit_induct                 ~> unit.induct
   951     prod_induct                 ~> prod.induct
   952     sum_induct                  ~> sum.induct
   953     Suc_Suc_eq                  ~> nat.inject
   954     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
   955 
   956 
   957 *** HOL-Algebra ***
   958 
   959 * New locales for orders and lattices where the equivalence relation
   960 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
   961 locales use a record structure with field eq for the equivalence.
   962 
   963 * New theory of factorial domains.
   964 
   965 * Units_l_inv and Units_r_inv are now simp rules by default.
   966 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
   967 and/or r_inv will now also require deletion of these lemmas.
   968 
   969 * Renamed the following theorems, INCOMPATIBILITY:
   970 
   971 UpperD ~> Upper_memD
   972 LowerD ~> Lower_memD
   973 least_carrier ~> least_closed
   974 greatest_carrier ~> greatest_closed
   975 greatest_Lower_above ~> greatest_Lower_below
   976 one_zero ~> carrier_one_zero
   977 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
   978 
   979 
   980 *** HOL-Nominal ***
   981 
   982 * Nominal datatypes can now contain type-variables.
   983 
   984 * Commands 'nominal_inductive' and 'equivariance' work with local
   985 theory targets.
   986 
   987 * Nominal primrec can now works with local theory targets and its
   988 specification syntax now conforms to the general format as seen in
   989 'inductive' etc.
   990 
   991 * Method "perm_simp" honours the standard simplifier attributes
   992 (no_asm), (no_asm_use) etc.
   993 
   994 * The new predicate #* is defined like freshness, except that on the
   995 left hand side can be a set or list of atoms.
   996 
   997 * Experimental command 'nominal_inductive2' derives strong induction
   998 principles for inductive definitions.  In contrast to
   999 'nominal_inductive', which can only deal with a fixed number of
  1000 binders, it can deal with arbitrary expressions standing for sets of
  1001 atoms to be avoided.  The only inductive definition we have at the
  1002 moment that needs this generalisation is the typing rule for Lets in
  1003 the algorithm W:
  1004 
  1005  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1006  -----------------------------------------------------------------
  1007          Gamma |- Let x be t1 in t2 : T2
  1008 
  1009 In this rule one wants to avoid all the binders that are introduced by
  1010 "close Gamma T1".  We are looking for other examples where this
  1011 feature might be useful.  Please let us know.
  1012 
  1013 
  1014 *** HOLCF ***
  1015 
  1016 * Reimplemented the simplification procedure for proving continuity
  1017 subgoals.  The new simproc is extensible; users can declare additional
  1018 continuity introduction rules with the attribute [cont2cont].
  1019 
  1020 * The continuity simproc now uses a different introduction rule for
  1021 solving continuity subgoals on terms with lambda abstractions.  In
  1022 some rare cases the new simproc may fail to solve subgoals that the
  1023 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1024 Potential INCOMPATIBILITY.
  1025 
  1026 * Command 'fixrec': specification syntax now conforms to the general
  1027 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1028 examples.  INCOMPATIBILITY.
  1029 
  1030 
  1031 *** ZF ***
  1032 
  1033 * Proof of Zorn's Lemma for partial orders.
  1034 
  1035 
  1036 *** ML ***
  1037 
  1038 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1039 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1040 depends on multithreading, so timouts will not work before Poly/ML
  1041 5.2.1!
  1042 
  1043 * High-level support for concurrent ML programming, see
  1044 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1045 particularly convenient to organize independent functional
  1046 computations.  The concept of "synchronized variables" provides a
  1047 higher-order interface for components with shared state, avoiding the
  1048 delicate details of mutexes and condition variables.  (Requires
  1049 Poly/ML 5.2.1 or later.)
  1050 
  1051 * ML bindings produced via Isar commands are stored within the Isar
  1052 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1053 become thread-safe and work with undo as expected (concerning
  1054 top-level bindings, not side-effects on global references).
  1055 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1056 compiler at runtime; really global bindings need to be given outside a
  1057 theory.  (Requires Poly/ML 5.2 or later.)
  1058 
  1059 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1060 context.  Top-level ML bindings are stored within the proof context in
  1061 a purely sequential fashion, disregarding the nested proof structure.
  1062 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1063 proof.  (Requires Poly/ML 5.2 or later.)
  1064 
  1065 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1066 and Method.setup, as well as Isar commands 'attribute_setup' and
  1067 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1068 existing code accordingly, or use plain 'setup' together with old
  1069 Method.add_method.
  1070 
  1071 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1072 to 'a -> thm, while results are always tagged with an authentic oracle
  1073 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1074 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1075 accordingly.  Note that extra performance may be gained by producing
  1076 the cterm carefully, avoiding slow Thm.cterm_of.
  1077 
  1078 * Simplified interface for defining document antiquotations via
  1079 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1080 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1081 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1082 examples.
  1083 
  1084 * More systematic treatment of long names, abstract name bindings, and
  1085 name space operations.  Basic operations on qualified names have been
  1086 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1087 Long_Name.append.  Old type bstring has been mostly replaced by
  1088 abstract type binding (see structure Binding), which supports precise
  1089 qualification by packages and local theory targets, as well as proper
  1090 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1091 bstring values into Binding.name, or better pass through abstract
  1092 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1093 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1094 
  1095 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1096 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1097 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1098 
  1099 * Disposed old type and term read functions (Sign.read_def_typ,
  1100 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1101 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1102 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1103 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1104 resort for legacy applications.
  1105 
  1106 * Disposed old declarations, tactics, tactic combinators that refer to
  1107 the simpset or claset of an implicit theory (such as Addsimps,
  1108 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1109 embedded ML text, or local_simpset_of with a proper context passed as
  1110 explicit runtime argument.
  1111 
  1112 * Rules and tactics that read instantiations (read_instantiate,
  1113 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1114 context, which is required for parsing and type-checking.  Moreover,
  1115 the variables are specified as plain indexnames, not string encodings
  1116 thereof.  INCOMPATIBILITY.
  1117 
  1118 * Generic Toplevel.add_hook interface allows to analyze the result of
  1119 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1120 for theorem dependency output of transactions resulting in a new
  1121 theory state.
  1122 
  1123 * ML antiquotations: block-structured compilation context indicated by
  1124 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1125 
  1126   @{binding name}                         - basic name binding
  1127   @{let ?pat = term}                      - term abbreviation (HO matching)
  1128   @{note name = fact}                     - fact abbreviation
  1129   @{thm fact}                             - singleton fact (with attributes)
  1130   @{thms fact}                            - general fact (with attributes)
  1131   @{lemma prop by method}                 - singleton goal
  1132   @{lemma prop by meth1 meth2}            - singleton goal
  1133   @{lemma prop1 ... propN by method}      - general goal
  1134   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1135   @{lemma (open) ...}                     - open derivation
  1136 
  1137 
  1138 *** System ***
  1139 
  1140 * The Isabelle "emacs" tool provides a specific interface to invoke
  1141 Proof General / Emacs, with more explicit failure if that is not
  1142 installed (the old isabelle-interface script silently falls back on
  1143 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1144 installation location of the Proof General distribution.
  1145 
  1146 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1147 the Isabelle process into a JVM/Scala application.  See
  1148 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1149 process wrapper has been discontinued.)
  1150 
  1151 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1152 
  1153 * Various status messages (with exact source position information) are
  1154 emitted, if proper markup print mode is enabled.  This allows
  1155 user-interface components to provide detailed feedback on internal
  1156 prover operations.
  1157 
  1158 
  1159 
  1160 New in Isabelle2008 (June 2008)
  1161 -------------------------------
  1162 
  1163 *** General ***
  1164 
  1165 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1166 and updated, with formally checked references as hyperlinks.
  1167 
  1168 * Theory loader: use_thy (and similar operations) no longer set the
  1169 implicit ML context, which was occasionally hard to predict and in
  1170 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1171 provides a proper context already.
  1172 
  1173 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1174 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1175 'use' within a theory file will do the job.
  1176 
  1177 * Name space merge now observes canonical order, i.e. the second space
  1178 is inserted into the first one, while existing entries in the first
  1179 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1180 swap theory imports.
  1181 
  1182 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1183 INCOMPATIBILITY in identifier syntax etc.
  1184 
  1185 * Outer syntax: string tokens no longer admit escaped white space,
  1186 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1187 white space without escapes.
  1188 
  1189 * Outer syntax: string tokens may contain arbitrary character codes
  1190 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1191 "foo_bar".
  1192 
  1193 
  1194 *** Pure ***
  1195 
  1196 * Context-dependent token translations.  Default setup reverts locally
  1197 fixed variables, and adds hilite markup for undeclared frees.
  1198 
  1199 * Unused theorems can be found using the new command 'unused_thms'.
  1200 There are three ways of invoking it:
  1201 
  1202 (1) unused_thms
  1203      Only finds unused theorems in the current theory.
  1204 
  1205 (2) unused_thms thy_1 ... thy_n -
  1206      Finds unused theorems in the current theory and all of its ancestors,
  1207      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1208 
  1209 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1210      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1211      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1212      their ancestors.
  1213 
  1214 In order to increase the readability of the list produced by
  1215 unused_thms, theorems that have been created by a particular instance
  1216 of a theory command such as 'inductive' or 'function' are considered
  1217 to belong to the same "group", meaning that if at least one theorem in
  1218 this group is used, the other theorems in the same group are no longer
  1219 reported as unused.  Moreover, if all theorems in the group are
  1220 unused, only one theorem in the group is displayed.
  1221 
  1222 Note that proof objects have to be switched on in order for
  1223 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1224 usually the case when using Proof General with the default settings).
  1225 
  1226 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1227 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1228 duplicate fact bindings, or even accidental fact duplications.  Note
  1229 that tools may maintain dynamically scoped facts systematically, using
  1230 PureThy.add_thms_dynamic.
  1231 
  1232 * Command 'hide' now allows to hide from "fact" name space as well.
  1233 
  1234 * Eliminated destructive theorem database, simpset, claset, and
  1235 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1236 update of theories within ML code.
  1237 
  1238 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1239 INCOMPATIBILITY, object-logics depending on former Pure require
  1240 additional setup PureThy.old_appl_syntax_setup; object-logics
  1241 depending on former CPure need to refer to Pure.
  1242 
  1243 * Commands 'use' and 'ML' are now purely functional, operating on
  1244 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1245 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1246 INCOMPATIBILITY.
  1247 
  1248 * Command 'setup': discontinued implicit version with ML reference.
  1249 
  1250 * Instantiation target allows for simultaneous specification of class
  1251 instance operations together with an instantiation proof.
  1252 Type-checking phase allows to refer to class operations uniformly.
  1253 See src/HOL/Complex/Complex.thy for an Isar example and
  1254 src/HOL/Library/Eval.thy for an ML example.
  1255 
  1256 * Indexing of literal facts: be more serious about including only
  1257 facts from the visible specification/proof context, but not the
  1258 background context (locale etc.).  Affects `prop` notation and method
  1259 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1260 situations.
  1261 
  1262 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1263 "(open)" option, which used to expose internal bound variables to the
  1264 proof text.
  1265 
  1266 * Isar statements: removed obsolete case "rule_context".
  1267 INCOMPATIBILITY, better use explicit fixes/assumes.
  1268 
  1269 * Locale proofs: default proof step now includes 'unfold_locales';
  1270 hence 'proof' without argument may be used to unfold locale
  1271 predicates.
  1272 
  1273 
  1274 *** Document preparation ***
  1275 
  1276 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1277 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1278 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1279 spot); renamed link color from "darkblue" to "linkcolor" (default
  1280 value unchanged, can be redefined via \definecolor); no longer sets
  1281 "a4paper" option (unnecessary or even intrusive).
  1282 
  1283 * Antiquotation @{lemma A method} proves proposition A by the given
  1284 method (either a method name or a method name plus (optional) method
  1285 arguments in parentheses) and prints A just like @{prop A}.
  1286 
  1287 
  1288 *** HOL ***
  1289 
  1290 * New primrec package.  Specification syntax conforms in style to
  1291 definition/function/....  No separate induction rule is provided.  The
  1292 "primrec" command distinguishes old-style and new-style specifications
  1293 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1294 When adjusting theories, beware: constants stemming from new-style
  1295 primrec specifications have authentic syntax.
  1296 
  1297 * Metis prover is now an order of magnitude faster, and also works
  1298 with multithreading.
  1299 
  1300 * Metis: the maximum number of clauses that can be produced from a
  1301 theorem is now given by the attribute max_clauses.  Theorems that
  1302 exceed this number are ignored, with a warning printed.
  1303 
  1304 * Sledgehammer no longer produces structured proofs by default. To
  1305 enable, declare [[sledgehammer_full = true]].  Attributes
  1306 reconstruction_modulus, reconstruction_sorts renamed
  1307 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1308 
  1309 * Method "induct_scheme" derives user-specified induction rules
  1310 from well-founded induction and completeness of patterns. This factors
  1311 out some operations that are done internally by the function package
  1312 and makes them available separately.  See
  1313 src/HOL/ex/Induction_Scheme.thy for examples.
  1314 
  1315 * More flexible generation of measure functions for termination
  1316 proofs: Measure functions can be declared by proving a rule of the
  1317 form "is_measure f" and giving it the [measure_function] attribute.
  1318 The "is_measure" predicate is logically meaningless (always true), and
  1319 just guides the heuristic.  To find suitable measure functions, the
  1320 termination prover sets up the goal "is_measure ?f" of the appropriate
  1321 type and generates all solutions by prolog-style backwards proof using
  1322 the declared rules.
  1323 
  1324 This setup also deals with rules like 
  1325 
  1326   "is_measure f ==> is_measure (list_size f)"
  1327 
  1328 which accommodates nested datatypes that recurse through lists.
  1329 Similar rules are predeclared for products and option types.
  1330 
  1331 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1332 
  1333   INCOMPATIBILITIES:
  1334 
  1335   - Definitions of overloaded constants on sets have to be replaced by
  1336     definitions on => and bool.
  1337 
  1338   - Some definitions of overloaded operators on sets can now be proved
  1339     using the definitions of the operators on => and bool.  Therefore,
  1340     the following theorems have been renamed:
  1341 
  1342       subset_def   -> subset_eq
  1343       psubset_def  -> psubset_eq
  1344       set_diff_def -> set_diff_eq
  1345       Compl_def    -> Compl_eq
  1346       Sup_set_def  -> Sup_set_eq
  1347       Inf_set_def  -> Inf_set_eq
  1348       sup_set_def  -> sup_set_eq
  1349       inf_set_def  -> inf_set_eq
  1350 
  1351   - Due to the incompleteness of the HO unification algorithm, some
  1352     rules such as subst may require manual instantiation, if some of
  1353     the unknowns in the rule is a set.
  1354 
  1355   - Higher order unification and forward proofs:
  1356     The proof pattern
  1357 
  1358       have "P (S::'a set)" <...>
  1359       then have "EX S. P S" ..
  1360 
  1361     no longer works (due to the incompleteness of the HO unification
  1362     algorithm) and must be replaced by the pattern
  1363 
  1364       have "EX S. P S"
  1365       proof
  1366         show "P S" <...>
  1367       qed
  1368 
  1369   - Calculational reasoning with subst (or similar rules):
  1370     The proof pattern
  1371 
  1372       have "P (S::'a set)" <...>
  1373       also have "S = T" <...>
  1374       finally have "P T" .
  1375 
  1376     no longer works (for similar reasons as the previous example) and
  1377     must be replaced by something like
  1378 
  1379       have "P (S::'a set)" <...>
  1380       moreover have "S = T" <...>
  1381       ultimately have "P T" by simp
  1382 
  1383   - Tactics or packages written in ML code:
  1384     Code performing pattern matching on types via
  1385 
  1386       Type ("set", [T]) => ...
  1387 
  1388     must be rewritten. Moreover, functions like strip_type or
  1389     binder_types no longer return the right value when applied to a
  1390     type of the form
  1391 
  1392       T1 => ... => Tn => U => bool
  1393 
  1394     rather than
  1395 
  1396       T1 => ... => Tn => U set
  1397 
  1398 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1399 Wellfounded_Relations to theory Wellfounded.
  1400 
  1401 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1402 
  1403 * Class finite no longer treats UNIV as class parameter.  Use class
  1404 enum from theory Library/Enum instead to achieve a similar effect.
  1405 INCOMPATIBILITY.
  1406 
  1407 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1408 and "Cons".  INCOMPATIBILITY.
  1409 
  1410 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1411 Potential INCOMPATIBILITY.
  1412 
  1413 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1414 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1415 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1416 
  1417 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1418 the same name in theory Orderings:
  1419 
  1420   less_trans
  1421   less_linear
  1422   le_imp_less_or_eq
  1423   le_less_trans
  1424   less_le_trans
  1425   less_not_sym
  1426   less_asym
  1427 
  1428 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1429 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1430 and different variable names.
  1431 
  1432 * Library/Option_ord.thy: Canonical order on option type.
  1433 
  1434 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1435 finite maps.
  1436 
  1437 * Library/Countable.thy: Type class for countable types.
  1438 
  1439 * Theory Int: The representation of numerals has changed.  The infix
  1440 operator BIT and the bit datatype with constructors B0 and B1 have
  1441 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1442 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1443 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1444 accordingly.
  1445 
  1446 * Theory Nat: definition of <= and < on natural numbers no longer
  1447 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1448 le_def and less_def have disappeared.  Consider lemmas not_less
  1449 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1450 
  1451 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1452 (whose purpose mainly is for various fold_set functionals) have been
  1453 abandoned in favor of the existing algebraic classes
  1454 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1455 lower_semilattice (resp. upper_semilattice) and linorder.
  1456 INCOMPATIBILITY.
  1457 
  1458 * Theory Transitive_Closure: induct and cases rules now declare proper
  1459 case_names ("base" and "step").  INCOMPATIBILITY.
  1460 
  1461 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1462 lattices.  The form set-specific version is available as
  1463 Inductive.lfp_ordinal_induct_set.
  1464 
  1465 * Renamed theorems "power.simps" to "power_int.simps".
  1466 INCOMPATIBILITY.
  1467 
  1468 * Class semiring_div provides basic abstract properties of semirings
  1469 with division and modulo operations.  Subsumes former class dvd_mod.
  1470 
  1471 * Merged theories IntDef, Numeral and IntArith into unified theory
  1472 Int.  INCOMPATIBILITY.
  1473 
  1474 * Theory Library/Code_Index: type "index" now represents natural
  1475 numbers rather than integers.  INCOMPATIBILITY.
  1476 
  1477 * New class "uminus" with operation "uminus" (split of from class
  1478 "minus" which now only has operation "minus", binary).
  1479 INCOMPATIBILITY.
  1480 
  1481 * Constants "card", "internal_split", "option_map" now with authentic
  1482 syntax.  INCOMPATIBILITY.
  1483 
  1484 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1485 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1486 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1487 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1488 Sup_set_def, le_def, less_def, option_map_def now with object
  1489 equality.  INCOMPATIBILITY.
  1490 
  1491 * Records. Removed K_record, and replaced it by pure lambda term
  1492 %x. c. The simplifier setup is now more robust against eta expansion.
  1493 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1494 
  1495 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1496 
  1497 * Library/ListVector: new theory of arithmetic vector operations.
  1498 
  1499 * Library/Order_Relation: new theory of various orderings as sets of
  1500 pairs.  Defines preorders, partial orders, linear orders and
  1501 well-orders on sets and on types.
  1502 
  1503 
  1504 *** ZF ***
  1505 
  1506 * Renamed some theories to allow to loading both ZF and HOL in the
  1507 same session:
  1508 
  1509   Datatype  -> Datatype_ZF
  1510   Inductive -> Inductive_ZF
  1511   Int       -> Int_ZF
  1512   IntDiv    -> IntDiv_ZF
  1513   Nat       -> Nat_ZF
  1514   List      -> List_ZF
  1515   Main      -> Main_ZF
  1516 
  1517 INCOMPATIBILITY: ZF theories that import individual theories below
  1518 Main might need to be adapted.  Regular theory Main is still
  1519 available, as trivial extension of Main_ZF.
  1520 
  1521 
  1522 *** ML ***
  1523 
  1524 * ML within Isar: antiquotation @{const name} or @{const
  1525 name(typargs)} produces statically-checked Const term.
  1526 
  1527 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1528 (of the same name).  Removed obsolete print command.
  1529 
  1530 * Removed obsolete "use_legacy_bindings" function.
  1531 
  1532 * The ``print mode'' is now a thread-local value derived from a global
  1533 template (the former print_mode reference), thus access becomes
  1534 non-critical.  The global print_mode reference is for session
  1535 management only; user-code should use print_mode_value,
  1536 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1537 
  1538 * Functions system/system_out provide a robust way to invoke external
  1539 shell commands, with propagation of interrupts (requires Poly/ML
  1540 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1541 
  1542 
  1543 *** System ***
  1544 
  1545 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1546 in accordance with Proof General 3.7, which prefers GNU emacs.
  1547 
  1548 * isatool tty runs Isabelle process with plain tty interaction;
  1549 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1550 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1551 
  1552 * isatool browser now works with Cygwin as well, using general
  1553 "javapath" function defined in Isabelle process environment.
  1554 
  1555 * YXML notation provides a simple and efficient alternative to
  1556 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1557 isatool yxml as described in the Isabelle system manual.
  1558 
  1559 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1560 provides general wrapper for managing an Isabelle process in a robust
  1561 fashion, with ``cooked'' output from stdin/stderr.
  1562 
  1563 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1564 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1565 
  1566 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1567 way of changing the user's settings is via
  1568 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1569 script.
  1570 
  1571 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1572 cores of the underlying machine, which is a good starting point for
  1573 optimal performance tuning.  The corresponding usedir option -M allows
  1574 "max" as an alias for "0".  WARNING: does not work on certain versions
  1575 of Mac OS (with Poly/ML 5.1).
  1576 
  1577 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1578 adverse effect of Isabelle flooding interactive front-ends (notably
  1579 ProofGeneral / XEmacs).
  1580 
  1581 
  1582 
  1583 New in Isabelle2007 (November 2007)
  1584 -----------------------------------
  1585 
  1586 *** General ***
  1587 
  1588 * More uniform information about legacy features, notably a
  1589 warning/error of "Legacy feature: ...", depending on the state of the
  1590 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1591 legacy features will disappear eventually.
  1592 
  1593 * Theory syntax: the header format ``theory A = B + C:'' has been
  1594 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1595 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1596 
  1597 * Theory syntax: the old non-Isar theory file format has been
  1598 discontinued altogether.  Note that ML proof scripts may still be used
  1599 with Isar theories; migration is usually quite simple with the ML
  1600 function use_legacy_bindings.  INCOMPATIBILITY.
  1601 
  1602 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1603 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1604 quotes.
  1605 
  1606 * Theory loader: be more serious about observing the static theory
  1607 header specifications (including optional directories), but not the
  1608 accidental file locations of previously successful loads.  The strict
  1609 update policy of former update_thy is now already performed by
  1610 use_thy, so the former has been removed; use_thys updates several
  1611 theories simultaneously, just as 'imports' within a theory header
  1612 specification, but without merging the results.  Potential
  1613 INCOMPATIBILITY: may need to refine theory headers and commands
  1614 ROOT.ML which depend on load order.
  1615 
  1616 * Theory loader: optional support for content-based file
  1617 identification, instead of the traditional scheme of full physical
  1618 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1619 (cf. the system manual).  The new scheme allows to work with
  1620 non-finished theories in persistent session images, such that source
  1621 files may be moved later on without requiring reloads.
  1622 
  1623 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1624 file (with the same base name as the theory) are considered a legacy
  1625 feature, which will disappear eventually. Even now, the theory loader
  1626 no longer maintains dependencies on such files.
  1627 
  1628 * Syntax: the scope for resolving ambiguities via type-inference is
  1629 now limited to individual terms, instead of whole simultaneous
  1630 specifications as before. This greatly reduces the complexity of the
  1631 syntax module and improves flexibility by separating parsing and
  1632 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1633 'fixes' etc.) are required in rare situations.
  1634 
  1635 * Syntax: constants introduced by new-style packages ('definition',
  1636 'abbreviation' etc.) are passed through the syntax module in
  1637 ``authentic mode''. This means that associated mixfix annotations
  1638 really stick to such constants, independently of potential name space
  1639 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1640 trees are represented slightly differently, may need to adapt syntax
  1641 translations accordingly. Use CONST marker in 'translations' and
  1642 @{const_syntax} antiquotation in 'parse_translation' etc.
  1643 
  1644 * Legacy goal package: reduced interface to the bare minimum required
  1645 to keep existing proof scripts running.  Most other user-level
  1646 functions are now part of the OldGoals structure, which is *not* open
  1647 by default (consider isatool expandshort before open OldGoals).
  1648 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1649 these tend to cause confusion about the actual goal (!) context being
  1650 used here, which is not necessarily the same as the_context().
  1651 
  1652 * Command 'find_theorems': supports "*" wild-card in "name:"
  1653 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1654 support a specific search form (see ProofGeneral/CHANGES).
  1655 
  1656 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1657 by default, which means that "prems" (and also "fixed variables") are
  1658 suppressed from proof state output.  Note that the ProofGeneral
  1659 settings mechanism allows to change and save options persistently, but
  1660 older versions of Isabelle will fail to start up if a negative prems
  1661 limit is imposed.
  1662 
  1663 * Local theory targets may be specified by non-nested blocks of
  1664 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1665 contain definitions, theorems etc., including any derived mechanism
  1666 that has been implemented on top of these primitives.  This concept
  1667 generalizes the existing ``theorem (in ...)'' towards more versatility
  1668 and scalability.
  1669 
  1670 * Proof General interface: proper undo of final 'end' command;
  1671 discontinued Isabelle/classic mode (ML proof scripts).
  1672 
  1673 
  1674 *** Document preparation ***
  1675 
  1676 * Added antiquotation @{theory name} which prints the given name,
  1677 after checking that it refers to a valid ancestor theory in the
  1678 current context.
  1679 
  1680 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1681 check the given source text as ML type/structure, printing verbatim.
  1682 
  1683 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1684 "c args == rhs" given in the current context.  (Any number of
  1685 arguments may be given on the LHS.)
  1686 
  1687 
  1688 *** Pure ***
  1689 
  1690 * The 'class' package offers a combination of axclass and locale to
  1691 achieve Haskell-like type classes in Isabelle.  Definitions and
  1692 theorems within a class context produce both relative results (with
  1693 implicit parameters according to the locale context), and polymorphic
  1694 constants with qualified polymorphism (according to the class
  1695 context).  Within the body context of a 'class' target, a separate
  1696 syntax layer ("user space type system") takes care of converting
  1697 between global polymorphic consts and internal locale representation.
  1698 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1699 "isatool doc classes" provides a tutorial.
  1700 
  1701 * Generic code generator framework allows to generate executable
  1702 code for ML and Haskell (including Isabelle classes).  A short usage
  1703 sketch:
  1704 
  1705     internal compilation:
  1706         export_code <list of constants (term syntax)> in SML
  1707     writing SML code to a file:
  1708         export_code <list of constants (term syntax)> in SML <filename>
  1709     writing OCaml code to a file:
  1710         export_code <list of constants (term syntax)> in OCaml <filename>
  1711     writing Haskell code to a bunch of files:
  1712         export_code <list of constants (term syntax)> in Haskell <filename>
  1713 
  1714     evaluating closed propositions to True/False using code generation:
  1715         method ``eval''
  1716 
  1717 Reasonable default setup of framework in HOL.
  1718 
  1719 Theorem attributs for selecting and transforming function equations theorems:
  1720 
  1721     [code fun]:        select a theorem as function equation for a specific constant
  1722     [code fun del]:    deselect a theorem as function equation for a specific constant
  1723     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1724     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1725 
  1726 User-defined serializations (target in {SML, OCaml, Haskell}):
  1727 
  1728     code_const <and-list of constants (term syntax)>
  1729       {(target) <and-list of const target syntax>}+
  1730 
  1731     code_type <and-list of type constructors>
  1732       {(target) <and-list of type target syntax>}+
  1733 
  1734     code_instance <and-list of instances>
  1735       {(target)}+
  1736         where instance ::= <type constructor> :: <class>
  1737 
  1738     code_class <and_list of classes>
  1739       {(target) <and-list of class target syntax>}+
  1740         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1741 
  1742 code_instance and code_class only are effective to target Haskell.
  1743 
  1744 For example usage see src/HOL/ex/Codegenerator.thy and
  1745 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1746 generation from Isabelle/HOL theories is available via "isatool doc
  1747 codegen".
  1748 
  1749 * Code generator: consts in 'consts_code' Isar commands are now
  1750 referred to by usual term syntax (including optional type
  1751 annotations).
  1752 
  1753 * Command 'no_translations' removes translation rules from theory
  1754 syntax.
  1755 
  1756 * Overloaded definitions are now actually checked for acyclic
  1757 dependencies.  The overloading scheme is slightly more general than
  1758 that of Haskell98, although Isabelle does not demand an exact
  1759 correspondence to type class and instance declarations.
  1760 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1761 exotic versions of overloading -- at the discretion of the user!
  1762 
  1763 Polymorphic constants are represented via type arguments, i.e. the
  1764 instantiation that matches an instance against the most general
  1765 declaration given in the signature.  For example, with the declaration
  1766 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1767 as c(nat).  Overloading is essentially simultaneous structural
  1768 recursion over such type arguments.  Incomplete specification patterns
  1769 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1770 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1771 Command 'print_theory' outputs the normalized system of recursive
  1772 equations, see section "definitions".
  1773 
  1774 * Configuration options are maintained within the theory or proof
  1775 context (with name and type bool/int/string), providing a very simple
  1776 interface to a poor-man's version of general context data.  Tools may
  1777 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1778 these values using Config.get etc.  Users may change options via an
  1779 associated attribute of the same name.  This form of context
  1780 declaration works particularly well with commands 'declare' or
  1781 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1782 very easy to avoid global references, which would not observe Isar
  1783 toplevel undo/redo and fail to work with multithreading.
  1784 
  1785 Various global ML references of Pure and HOL have been turned into
  1786 configuration options:
  1787 
  1788   Unify.search_bound		unify_search_bound
  1789   Unify.trace_bound		unify_trace_bound
  1790   Unify.trace_simp		unify_trace_simp
  1791   Unify.trace_types		unify_trace_types
  1792   Simplifier.simp_depth_limit	simp_depth_limit
  1793   Blast.depth_limit		blast_depth_limit
  1794   DatatypeProp.dtK		datatype_distinctness_limit
  1795   fast_arith_neq_limit  	fast_arith_neq_limit
  1796   fast_arith_split_limit	fast_arith_split_limit
  1797 
  1798 * Named collections of theorems may be easily installed as context
  1799 data using the functor NamedThmsFun (see also
  1800 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1801 attributes; there is also a toplevel print command.  This facility is
  1802 just a common case of general context data, which is the preferred way
  1803 for anything more complex than just a list of facts in canonical
  1804 order.
  1805 
  1806 * Isar: command 'declaration' augments a local theory by generic
  1807 declaration functions written in ML.  This enables arbitrary content
  1808 being added to the context, depending on a morphism that tells the
  1809 difference of the original declaration context wrt. the application
  1810 context encountered later on.
  1811 
  1812 * Isar: proper interfaces for simplification procedures.  Command
  1813 'simproc_setup' declares named simprocs (with match patterns, and body
  1814 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1815 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1816 
  1817 * Isar: an extra pair of brackets around attribute declarations
  1818 abbreviates a theorem reference involving an internal dummy fact,
  1819 which will be ignored later --- only the effect of the attribute on
  1820 the background context will persist.  This form of in-place
  1821 declarations is particularly useful with commands like 'declare' and
  1822 'using', for example ``have A using [[simproc a]] by simp''.
  1823 
  1824 * Isar: method "assumption" (and implicit closing of subproofs) now
  1825 takes simple non-atomic goal assumptions into account: after applying
  1826 an assumption as a rule the resulting subgoals are solved by atomic
  1827 assumption steps.  This is particularly useful to finish 'obtain'
  1828 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1829 without referring to the original premise "!!x. P x ==> thesis" in the
  1830 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1831 more permissive.
  1832 
  1833 * Isar: implicit use of prems from the Isar proof context is
  1834 considered a legacy feature.  Common applications like ``have A .''
  1835 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1836 referencing facts explicitly here improves readability and
  1837 maintainability of proof texts.
  1838 
  1839 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1840 the obtained context from the course of reasoning!  For example:
  1841 
  1842   assume "EX x y. A x & B y"   -- "any previous fact"
  1843   then guess x and y by clarify
  1844 
  1845 This technique is potentially adventurous, depending on the facts and
  1846 proof tools being involved here.
  1847 
  1848 * Isar: known facts from the proof context may be specified as literal
  1849 propositions, using ASCII back-quote syntax.  This works wherever
  1850 named facts used to be allowed so far, in proof commands, proof
  1851 methods, attributes etc.  Literal facts are retrieved from the context
  1852 according to unification of type and term parameters.  For example,
  1853 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1854 theorems in the current context, then these are valid literal facts:
  1855 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1856 
  1857 There is also a proof method "fact" which does the same composition
  1858 for explicit goal states, e.g. the following proof texts coincide with
  1859 certain special cases of literal facts:
  1860 
  1861   have "A" by fact                 ==  note `A`
  1862   have "A ==> B" by fact           ==  note `A ==> B`
  1863   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1864   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1865 
  1866 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1867 outer syntax.  Thus symbolic identifiers may be used without
  1868 additional white space in declarations like this: ``assume *: A''.
  1869 
  1870 * Isar: 'print_facts' prints all local facts of the current context,
  1871 both named and unnamed ones.
  1872 
  1873 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1874 
  1875   def x == "t" and y == "u"
  1876 
  1877 * Isar: added command 'unfolding', which is structurally similar to
  1878 'using', but affects both the goal state and facts by unfolding given
  1879 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1880 'unfolded' attribute may be replaced by first-class proof text.
  1881 
  1882 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1883 and command 'unfolding' now all support object-level equalities
  1884 (potentially conditional).  The underlying notion of rewrite rule is
  1885 analogous to the 'rule_format' attribute, but *not* that of the
  1886 Simplifier (which is usually more generous).
  1887 
  1888 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1889 premises of a theorem by n. Useful in conjunction with drule.
  1890 
  1891 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1892 method expression within a sandbox consisting of the first N
  1893 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1894 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1895 simplifies all new goals that emerge from applying rule foo to the
  1896 originally first one.
  1897 
  1898 * Isar: schematic goals are no longer restricted to higher-order
  1899 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1900 expected.
  1901 
  1902 * Isar: the conclusion of a long theorem statement is now either
  1903 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1904 (essentially a disjunction of cases with local parameters and
  1905 assumptions).  The latter allows to express general elimination rules
  1906 adequately; in this notation common elimination rules look like this:
  1907 
  1908   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1909     assumes "EX x. P x"
  1910     obtains x where "P x"
  1911 
  1912   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1913     assumes "A & B"
  1914     obtains A and B
  1915 
  1916   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1917     assumes "A | B"
  1918     obtains
  1919       A
  1920     | B
  1921 
  1922 The subsequent classical rules even refer to the formal "thesis"
  1923 explicitly:
  1924 
  1925   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1926     obtains "~ thesis"
  1927 
  1928   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1929     obtains "thesis ==> something"
  1930 
  1931 The actual proof of an 'obtains' statement is analogous to that of the
  1932 Isar proof element 'obtain', only that there may be several cases.
  1933 Optional case names may be specified in parentheses; these will be
  1934 available both in the present proof and as annotations in the
  1935 resulting rule, for later use with the 'cases' method (cf. attribute
  1936 case_names).
  1937 
  1938 * Isar: the assumptions of a long theorem statement are available as
  1939 "assms" fact in the proof context.  This is more appropriate than the
  1940 (historical) "prems", which refers to all assumptions of the current
  1941 context, including those from the target locale, proof body etc.
  1942 
  1943 * Isar: 'print_statement' prints theorems from the current theory or
  1944 proof context in long statement form, according to the syntax of a
  1945 top-level lemma.
  1946 
  1947 * Isar: 'obtain' takes an optional case name for the local context
  1948 introduction rule (default "that").
  1949 
  1950 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  1951 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  1952 to occur.
  1953 
  1954 * Pure: syntax "CONST name" produces a fully internalized constant
  1955 according to the current context.  This is particularly useful for
  1956 syntax translations that should refer to internal constant
  1957 representations independently of name spaces.
  1958 
  1959 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  1960 instead of "FOO ". This allows multiple binder declarations to coexist
  1961 in the same context.  INCOMPATIBILITY.
  1962 
  1963 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  1964 primitive that also works in a locale context (both for constants and
  1965 fixed variables). Type declaration and internal syntactic representation
  1966 of given constants retrieved from the context. Likewise, the
  1967 'no_notation' command allows to remove given syntax annotations from the
  1968 current context.
  1969 
  1970 * Isar/locales: new derived specification elements 'axiomatization',
  1971 'definition', 'abbreviation', which support type-inference, admit
  1972 object-level specifications (equality, equivalence).  See also the
  1973 isar-ref manual.  Examples:
  1974 
  1975   axiomatization
  1976     eq  (infix "===" 50) where
  1977     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  1978 
  1979   definition "f x y = x + y + 1"
  1980   definition g where "g x = f x x"
  1981 
  1982   abbreviation
  1983     neq  (infix "=!=" 50) where
  1984     "x =!= y == ~ (x === y)"
  1985 
  1986 These specifications may be also used in a locale context.  Then the
  1987 constants being introduced depend on certain fixed parameters, and the
  1988 constant name is qualified by the locale base name.  An internal
  1989 abbreviation takes care for convenient input and output, making the
  1990 parameters implicit and using the original short name.  See also
  1991 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  1992 entities from a monomorphic theory.
  1993 
  1994 Presently, abbreviations are only available 'in' a target locale, but
  1995 not inherited by general import expressions.  Also note that
  1996 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  1997 'translations' in common applications.  The "no_abbrevs" print mode
  1998 prevents folding of abbreviations in term output.
  1999 
  2000 Concrete syntax is attached to specified constants in internal form,
  2001 independently of name spaces.  The parse tree representation is
  2002 slightly different -- use 'notation' instead of raw 'syntax', and
  2003 'translations' with explicit "CONST" markup to accommodate this.
  2004 
  2005 * Pure/Isar: unified syntax for new-style specification mechanisms
  2006 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2007 full type inference and dummy patterns ("_").  For example:
  2008 
  2009   definition "K x _ = x"
  2010 
  2011   inductive conj for A B
  2012   where "A ==> B ==> conj A B"
  2013 
  2014 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2015 the current context.  Print mode "no_abbrevs" prevents inversion of
  2016 abbreviations on output.
  2017 
  2018 * Isar/locales: improved parameter handling: use of locales "var" and
  2019 "struct" no longer necessary; - parameter renamings are no longer
  2020 required to be injective.  For example, this allows to define
  2021 endomorphisms as locale endom = homom mult mult h.
  2022 
  2023 * Isar/locales: changed the way locales with predicates are defined.
  2024 Instead of accumulating the specification, the imported expression is
  2025 now an interpretation.  INCOMPATIBILITY: different normal form of
  2026 locale expressions.  In particular, in interpretations of locales with
  2027 predicates, goals repesenting already interpreted fragments are not
  2028 removed automatically.  Use methods `intro_locales' and
  2029 `unfold_locales'; see below.
  2030 
  2031 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2032 provide backward reasoning on locales predicates.  The methods are
  2033 aware of interpretations and discharge corresponding goals.
  2034 `intro_locales' is less aggressive then `unfold_locales' and does not
  2035 unfold predicates to assumptions.
  2036 
  2037 * Isar/locales: the order in which locale fragments are accumulated
  2038 has changed.  This enables to override declarations from fragments due
  2039 to interpretations -- for example, unwanted simp rules.
  2040 
  2041 * Isar/locales: interpretation in theories and proof contexts has been
  2042 extended.  One may now specify (and prove) equations, which are
  2043 unfolded in interpreted theorems.  This is useful for replacing
  2044 defined concepts (constants depending on locale parameters) by
  2045 concepts already existing in the target context.  Example:
  2046 
  2047   interpretation partial_order ["op <= :: [int, int] => bool"]
  2048     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2049 
  2050 Typically, the constant `partial_order.less' is created by a
  2051 definition specification element in the context of locale
  2052 partial_order.
  2053 
  2054 * Method "induct": improved internal context management to support
  2055 local fixes and defines on-the-fly. Thus explicit meta-level
  2056 connectives !!  and ==> are rarely required anymore in inductive goals
  2057 (using object-logic connectives for this purpose has been long
  2058 obsolete anyway). Common proof patterns are explained in
  2059 src/HOL/Induct/Common_Patterns.thy, see also
  2060 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2061 examples.
  2062 
  2063 * Method "induct": improved handling of simultaneous goals. Instead of
  2064 introducing object-level conjunction, the statement is now split into
  2065 several conclusions, while the corresponding symbolic cases are nested
  2066 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2067 see src/HOL/Induct/Common_Patterns.thy, for example.
  2068 
  2069 * Method "induct": mutual induction rules are now specified as a list
  2070 of rule sharing the same induction cases. HOL packages usually provide
  2071 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2072 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2073 mutual induction rules differently, i.e. like this:
  2074 
  2075   (induct rule: foo_bar.inducts)
  2076   (induct set: foo bar)
  2077   (induct pred: foo bar)
  2078   (induct type: foo bar)
  2079 
  2080 The ML function ProjectRule.projections turns old-style rules into the
  2081 new format.
  2082 
  2083 * Method "coinduct": dual of induction, see
  2084 src/HOL/Library/Coinductive_List.thy for various examples.
  2085 
  2086 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2087 considered a legacy feature.
  2088 
  2089 * Attribute "symmetric" produces result with standardized schematic
  2090 variables (index 0).  Potential INCOMPATIBILITY.
  2091 
  2092 * Simplifier: by default the simplifier trace only shows top level
  2093 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2094 default. Thus there is less danger of being flooded by the trace. The
  2095 trace indicates where parts have been suppressed.
  2096   
  2097 * Provers/classical: removed obsolete classical version of elim_format
  2098 attribute; classical elim/dest rules are now treated uniformly when
  2099 manipulating the claset.
  2100 
  2101 * Provers/classical: stricter checks to ensure that supplied intro,
  2102 dest and elim rules are well-formed; dest and elim rules must have at
  2103 least one premise.
  2104 
  2105 * Provers/classical: attributes dest/elim/intro take an optional
  2106 weight argument for the rule (just as the Pure versions).  Weights are
  2107 ignored by automated tools, but determine the search order of single
  2108 rule steps.
  2109 
  2110 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2111 where the body does not mention the bound variable.  Note that dummy
  2112 patterns implicitly depend on their context of bounds, which makes
  2113 "{_. _}" match any set comprehension as expected.  Potential
  2114 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2115 constant "_idtdummy" in the binding position.
  2116 
  2117 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2118 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2119 for example "A -> B" => "Pi A (%_. B)".
  2120 
  2121 * Pure: 'class_deps' command visualizes the subclass relation, using
  2122 the graph browser tool.
  2123 
  2124 * Pure: 'print_theory' now suppresses certain internal declarations by
  2125 default; use '!' option for full details.
  2126 
  2127 
  2128 *** HOL ***
  2129 
  2130 * Method "metis" proves goals by applying the Metis general-purpose
  2131 resolution prover (see also http://gilith.com/software/metis/).
  2132 Examples are in the directory MetisExamples.  WARNING: the
  2133 Isabelle/HOL-Metis integration does not yet work properly with
  2134 multi-threading.
  2135   
  2136 * Command 'sledgehammer' invokes external automatic theorem provers as
  2137 background processes.  It generates calls to the "metis" method if
  2138 successful. These can be pasted into the proof.  Users do not have to
  2139 wait for the automatic provers to return.  WARNING: does not really
  2140 work with multi-threading.
  2141 
  2142 * New "auto_quickcheck" feature tests outermost goal statements for
  2143 potential counter-examples.  Controlled by ML references
  2144 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2145 5000 milliseconds).  Fails silently if statements is outside of
  2146 executable fragment, or any other codgenerator problem occurs.
  2147 
  2148 * New constant "undefined" with axiom "undefined x = undefined".
  2149 
  2150 * Added class "HOL.eq", allowing for code generation with polymorphic
  2151 equality.
  2152 
  2153 * Some renaming of class constants due to canonical name prefixing in
  2154 the new 'class' package:
  2155 
  2156     HOL.abs ~> HOL.abs_class.abs
  2157     HOL.divide ~> HOL.divide_class.divide
  2158     0 ~> HOL.zero_class.zero
  2159     1 ~> HOL.one_class.one
  2160     op + ~> HOL.plus_class.plus
  2161     op - ~> HOL.minus_class.minus
  2162     uminus ~> HOL.minus_class.uminus
  2163     op * ~> HOL.times_class.times
  2164     op < ~> HOL.ord_class.less
  2165     op <= > HOL.ord_class.less_eq
  2166     Nat.power ~> Power.power_class.power
  2167     Nat.size ~> Nat.size_class.size
  2168     Numeral.number_of ~> Numeral.number_class.number_of
  2169     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2170     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2171     Orderings.min ~> Orderings.ord_class.min
  2172     Orderings.max ~> Orderings.ord_class.max
  2173     Divides.op div ~> Divides.div_class.div
  2174     Divides.op mod ~> Divides.div_class.mod
  2175     Divides.op dvd ~> Divides.div_class.dvd
  2176 
  2177 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2178 
  2179 a) User-defined constants using any of the names "plus", "minus",
  2180 "times", "less" or "less_eq". The standard syntax translations for
  2181 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2182 names.
  2183 
  2184 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2185 INCOMPATIBILITY: use more specific names.
  2186 
  2187 c) Permutative equations (e.g. "a + b = b + a")
  2188 Since the change of names also changes the order of terms, permutative
  2189 rewrite rules may get applied in a different order. Experience shows
  2190 that this is rarely the case (only two adaptions in the whole Isabelle
  2191 distribution).  INCOMPATIBILITY: rewrite proofs
  2192 
  2193 d) ML code directly refering to constant names
  2194 This in general only affects hand-written proof tactics, simprocs and
  2195 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2196 Consider using @{const_name} antiquotation.
  2197 
  2198 * New class "default" with associated constant "default".
  2199 
  2200 * Function "sgn" is now overloaded and available on int, real, complex
  2201 (and other numeric types), using class "sgn".  Two possible defs of
  2202 sgn are given as equational assumptions in the classes sgn_if and
  2203 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2204 INCOMPATIBILITY.
  2205 
  2206 * Locale "partial_order" now unified with class "order" (cf. theory
  2207 Orderings), added parameter "less".  INCOMPATIBILITY.
  2208 
  2209 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2210 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2211 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2212 
  2213 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2214 changed order of proof goals in instance proofs.
  2215 
  2216 * The transitivity reasoner for partial and linear orders is set up
  2217 for classes "order" and "linorder".  Instances of the reasoner are available
  2218 in all contexts importing or interpreting the corresponding locales.
  2219 Method "order" invokes the reasoner separately; the reasoner
  2220 is also integrated with the Simplifier as a solver.  Diagnostic
  2221 command 'print_orders' shows the available instances of the reasoner
  2222 in the current context.
  2223 
  2224 * Localized monotonicity predicate in theory "Orderings"; integrated
  2225 lemmas max_of_mono and min_of_mono with this predicate.
  2226 INCOMPATIBILITY.
  2227 
  2228 * Formulation of theorem "dense" changed slightly due to integration
  2229 with new class dense_linear_order.
  2230 
  2231 * Uniform lattice theory development in HOL.
  2232 
  2233     constants "meet" and "join" now named "inf" and "sup"
  2234     constant "Meet" now named "Inf"
  2235 
  2236     classes "meet_semilorder" and "join_semilorder" now named
  2237       "lower_semilattice" and "upper_semilattice"
  2238     class "lorder" now named "lattice"
  2239     class "comp_lat" now named "complete_lattice"
  2240 
  2241     Instantiation of lattice classes allows explicit definitions
  2242     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2243 
  2244   INCOMPATIBILITY.  Theorem renames:
  2245 
  2246     meet_left_le            ~> inf_le1
  2247     meet_right_le           ~> inf_le2
  2248     join_left_le            ~> sup_ge1
  2249     join_right_le           ~> sup_ge2
  2250     meet_join_le            ~> inf_sup_ord
  2251     le_meetI                ~> le_infI
  2252     join_leI                ~> le_supI
  2253     le_meet                 ~> le_inf_iff
  2254     le_join                 ~> ge_sup_conv
  2255     meet_idempotent         ~> inf_idem
  2256     join_idempotent         ~> sup_idem
  2257     meet_comm               ~> inf_commute
  2258     join_comm               ~> sup_commute
  2259     meet_leI1               ~> le_infI1
  2260     meet_leI2               ~> le_infI2
  2261     le_joinI1               ~> le_supI1
  2262     le_joinI2               ~> le_supI2
  2263     meet_assoc              ~> inf_assoc
  2264     join_assoc              ~> sup_assoc
  2265     meet_left_comm          ~> inf_left_commute
  2266     meet_left_idempotent    ~> inf_left_idem
  2267     join_left_comm          ~> sup_left_commute
  2268     join_left_idempotent    ~> sup_left_idem
  2269     meet_aci                ~> inf_aci
  2270     join_aci                ~> sup_aci
  2271     le_def_meet             ~> le_iff_inf
  2272     le_def_join             ~> le_iff_sup
  2273     join_absorp2            ~> sup_absorb2
  2274     join_absorp1            ~> sup_absorb1
  2275     meet_absorp1            ~> inf_absorb1
  2276     meet_absorp2            ~> inf_absorb2
  2277     meet_join_absorp        ~> inf_sup_absorb
  2278     join_meet_absorp        ~> sup_inf_absorb
  2279     distrib_join_le         ~> distrib_sup_le
  2280     distrib_meet_le         ~> distrib_inf_le
  2281 
  2282     add_meet_distrib_left   ~> add_inf_distrib_left
  2283     add_join_distrib_left   ~> add_sup_distrib_left
  2284     is_join_neg_meet        ~> is_join_neg_inf
  2285     is_meet_neg_join        ~> is_meet_neg_sup
  2286     add_meet_distrib_right  ~> add_inf_distrib_right
  2287     add_join_distrib_right  ~> add_sup_distrib_right
  2288     add_meet_join_distribs  ~> add_sup_inf_distribs
  2289     join_eq_neg_meet        ~> sup_eq_neg_inf
  2290     meet_eq_neg_join        ~> inf_eq_neg_sup
  2291     add_eq_meet_join        ~> add_eq_inf_sup
  2292     meet_0_imp_0            ~> inf_0_imp_0
  2293     join_0_imp_0            ~> sup_0_imp_0
  2294     meet_0_eq_0             ~> inf_0_eq_0
  2295     join_0_eq_0             ~> sup_0_eq_0
  2296     neg_meet_eq_join        ~> neg_inf_eq_sup
  2297     neg_join_eq_meet        ~> neg_sup_eq_inf
  2298     join_eq_if              ~> sup_eq_if
  2299 
  2300     mono_meet               ~> mono_inf
  2301     mono_join               ~> mono_sup
  2302     meet_bool_eq            ~> inf_bool_eq
  2303     join_bool_eq            ~> sup_bool_eq
  2304     meet_fun_eq             ~> inf_fun_eq
  2305     join_fun_eq             ~> sup_fun_eq
  2306     meet_set_eq             ~> inf_set_eq
  2307     join_set_eq             ~> sup_set_eq
  2308     meet1_iff               ~> inf1_iff
  2309     meet2_iff               ~> inf2_iff
  2310     meet1I                  ~> inf1I
  2311     meet2I                  ~> inf2I
  2312     meet1D1                 ~> inf1D1
  2313     meet2D1                 ~> inf2D1
  2314     meet1D2                 ~> inf1D2
  2315     meet2D2                 ~> inf2D2
  2316     meet1E                  ~> inf1E
  2317     meet2E                  ~> inf2E
  2318     join1_iff               ~> sup1_iff
  2319     join2_iff               ~> sup2_iff
  2320     join1I1                 ~> sup1I1
  2321     join2I1                 ~> sup2I1
  2322     join1I1                 ~> sup1I1
  2323     join2I2                 ~> sup1I2
  2324     join1CI                 ~> sup1CI
  2325     join2CI                 ~> sup2CI
  2326     join1E                  ~> sup1E
  2327     join2E                  ~> sup2E
  2328 
  2329     is_meet_Meet            ~> is_meet_Inf
  2330     Meet_bool_def           ~> Inf_bool_def
  2331     Meet_fun_def            ~> Inf_fun_def
  2332     Meet_greatest           ~> Inf_greatest
  2333     Meet_lower              ~> Inf_lower
  2334     Meet_set_def            ~> Inf_set_def
  2335 
  2336     Sup_def                 ~> Sup_Inf
  2337     Sup_bool_eq             ~> Sup_bool_def
  2338     Sup_fun_eq              ~> Sup_fun_def
  2339     Sup_set_eq              ~> Sup_set_def
  2340 
  2341     listsp_meetI            ~> listsp_infI
  2342     listsp_meet_eq          ~> listsp_inf_eq
  2343 
  2344     meet_min                ~> inf_min
  2345     join_max                ~> sup_max
  2346 
  2347 * Added syntactic class "size"; overloaded constant "size" now has
  2348 type "'a::size ==> bool"
  2349 
  2350 * Internal reorganisation of `size' of datatypes: size theorems
  2351 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2352 simplification rules by default!); theorems "prod.size" now named
  2353 "*.size".
  2354 
  2355 * Class "div" now inherits from class "times" rather than "type".
  2356 INCOMPATIBILITY.
  2357 
  2358 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2359 Linorder etc.  have disappeared; operations defined in terms of
  2360 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2361 
  2362 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2363 
  2364 * HOL-Word: New extensive library and type for generic, fixed size
  2365 machine words, with arithemtic, bit-wise, shifting and rotating
  2366 operations, reflection into int, nat, and bool lists, automation for
  2367 linear arithmetic (by automatic reflection into nat or int), including
  2368 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2369 arithmetic type classes, supporting automatic simplification of
  2370 numerals on all operations.
  2371 
  2372 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2373 
  2374 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2375 
  2376 * Code generator library theories:
  2377   - Code_Integer represents HOL integers by big integer literals in target
  2378     languages.
  2379   - Code_Char represents HOL characters by character literals in target
  2380     languages.
  2381   - Code_Char_chr like Code_Char, but also offers treatment of character
  2382     codes; includes Code_Integer.
  2383   - Executable_Set allows to generate code for finite sets using lists.
  2384   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2385     denominator).
  2386   - Executable_Real implements a subset of real numbers, namly those
  2387     representable by rational numbers.
  2388   - Efficient_Nat implements natural numbers by integers, which in general will
  2389     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2390     includes Code_Integer.
  2391   - Code_Index provides an additional datatype index which is mapped to
  2392     target-language built-in integers.
  2393   - Code_Message provides an additional datatype message_string which is isomorphic to
  2394     strings; messages are mapped to target-language strings.
  2395 
  2396 * New package for inductive predicates
  2397 
  2398   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2399 
  2400     inductive
  2401       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2402       for z_1 :: U_1 and ... and z_n :: U_m
  2403     where
  2404       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2405     | ...
  2406 
  2407   with full support for type-inference, rather than
  2408 
  2409     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2410 
  2411     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2412     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2413 
  2414     inductive "s z_1 ... z_m"
  2415     intros
  2416       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2417       ...
  2418 
  2419   For backward compatibility, there is a wrapper allowing inductive
  2420   sets to be defined with the new package via
  2421 
  2422     inductive_set
  2423       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2424       for z_1 :: U_1 and ... and z_n :: U_m
  2425     where
  2426       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2427     | ...
  2428 
  2429   or
  2430 
  2431     inductive_set
  2432       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2433       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2434       for z_1 :: U_1 and ... and z_n :: U_m
  2435     where
  2436       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2437     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2438     | ...
  2439 
  2440   if the additional syntax "p ..." is required.
  2441 
  2442   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2443   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2444 
  2445   INCOMPATIBILITIES:
  2446 
  2447   - Since declaration and definition of inductive sets or predicates
  2448     is no longer separated, abbreviations involving the newly
  2449     introduced sets or predicates must be specified together with the
  2450     introduction rules after the 'where' keyword (see above), rather
  2451     than before the actual inductive definition.
  2452 
  2453   - The variables in induction and elimination rules are now
  2454     quantified in the order of their occurrence in the introduction
  2455     rules, rather than in alphabetical order. Since this may break
  2456     some proofs, these proofs either have to be repaired, e.g. by
  2457     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2458     statements of the form
  2459 
  2460       case (rule_i a_i_1 ... a_i_{k_i})
  2461 
  2462     or the old order of quantification has to be restored by explicitly adding
  2463     meta-level quantifiers in the introduction rules, i.e.
  2464 
  2465       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2466 
  2467   - The format of the elimination rules is now
  2468 
  2469       p z_1 ... z_m x_1 ... x_n ==>
  2470         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2471         ==> ... ==> P
  2472 
  2473     for predicates and
  2474 
  2475       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2476         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2477         ==> ... ==> P
  2478 
  2479     for sets rather than
  2480 
  2481       x : s z_1 ... z_m ==>
  2482         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2483         ==> ... ==> P
  2484 
  2485     This may require terms in goals to be expanded to n-tuples
  2486     (e.g. using case_tac or simplification with the split_paired_all
  2487     rule) before the above elimination rule is applicable.
  2488 
  2489   - The elimination or case analysis rules for (mutually) inductive
  2490     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2491     list of rules "p_1_..._p_k.elims" is no longer available.
  2492 
  2493 * New package "function"/"fun" for general recursive functions,
  2494 supporting mutual and nested recursion, definitions in local contexts,
  2495 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2496 for small examples, and the separate tutorial on the function
  2497 package. The old recdef "package" is still available as before, but
  2498 users are encouraged to use the new package.
  2499 
  2500 * Method "lexicographic_order" automatically synthesizes termination
  2501 relations as lexicographic combinations of size measures. 
  2502 
  2503 * Case-expressions allow arbitrary constructor-patterns (including
  2504 "_") and take their order into account, like in functional
  2505 programming.  Internally, this is translated into nested
  2506 case-expressions; missing cases are added and mapped to the predefined
  2507 constant "undefined". In complicated cases printing may no longer show
  2508 the original input but the internal form. Lambda-abstractions allow
  2509 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2510 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2511 variable.
  2512 
  2513 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2514 is an abbreviation for "of_nat :: nat => int". The simplification
  2515 rules for "of_nat" have been changed to work like "int" did
  2516 previously.  Potential INCOMPATIBILITY:
  2517   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2518   - of_nat_diff and of_nat_mult are no longer default simp rules
  2519 
  2520 * Method "algebra" solves polynomial equations over (semi)rings using
  2521 Groebner bases. The (semi)ring structure is defined by locales and the
  2522 tool setup depends on that generic context. Installing the method for
  2523 a specific type involves instantiating the locale and possibly adding
  2524 declarations for computation on the coefficients.  The method is
  2525 already instantiated for natural numbers and for the axiomatic class
  2526 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2527 CALCULEMUS 2007 for the general principles underlying this
  2528 architecture of context-aware proof-tools.
  2529 
  2530 * Method "ferrack" implements quantifier elimination over
  2531 special-purpose dense linear orders using locales (analogous to
  2532 "algebra"). The method is already installed for class
  2533 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2534 rat, etc.
  2535 
  2536 * Former constant "List.op @" now named "List.append".  Use ML
  2537 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2538 circumvent possible incompatibilities when working on ML level.
  2539 
  2540 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2541 
  2542 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2543 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2544 
  2545 * New syntax for Haskell-like list comprehension (input only), eg.
  2546 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2547 
  2548 * The special syntax for function "filter" has changed from [x :
  2549 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2550 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2551 
  2552 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2553 defined on nat only, as an abbreviation for [a..<Suc b]
  2554 INCOMPATIBILITY.
  2555 
  2556 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2557 
  2558 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2559 
  2560 * New lemma collection field_simps (an extension of ring_simps) for
  2561 manipulating (in)equations involving division. Multiplies with all
  2562 denominators that can be proved to be non-zero (in equations) or
  2563 positive/negative (in inequations).
  2564 
  2565 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2566 have been improved and renamed to ring_simps, group_simps and
  2567 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2568 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2569 
  2570 * Theory Library/Commutative_Ring: switched from recdef to function
  2571 package; constants add, mul, pow now curried.  Infix syntax for
  2572 algebraic operations.
  2573 
  2574 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2575 INCOMPATIBILITY.
  2576 
  2577 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2578 INCOMPATIBILITY.
  2579 
  2580 * HOL/records: generalised field-update to take a function on the
  2581 field rather than the new value: r(|A := x|) is translated to A_update
  2582 (K x) r The K-combinator that is internally used is called K_record.
  2583 INCOMPATIBILITY: Usage of the plain update functions has to be
  2584 adapted.
  2585  
  2586 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2587 * x = 0, which are required for a semiring.  Richer structures do not
  2588 inherit from semiring_0 anymore, because this property is a theorem
  2589 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2590 there is more to prove, but this is mostly trivial.
  2591 
  2592 * Class "recpower" is generalized to arbitrary monoids, not just
  2593 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2594 commutativity or semiring properties additionally.
  2595 
  2596 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2597 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2598 better use 'abbreviation'.
  2599 
  2600 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2601 
  2602 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2603 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2604 significant changes for setting up numeral syntax for types:
  2605   - New constants Numeral.pred and Numeral.succ instead
  2606       of former Numeral.bin_pred and Numeral.bin_succ.
  2607   - Use integer operations instead of bin_add, bin_mult and so on.
  2608   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2609   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2610 
  2611 See src/HOL/Integ/IntArith.thy for an example setup.
  2612 
  2613 * Command 'normal_form' computes the normal form of a term that may
  2614 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2615 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2616 heavy-duty computations because the functions are compiled to ML
  2617 first.  Correspondingly, a method "normalization" is provided.  See
  2618 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2619 
  2620 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2621 25 like -->); output depends on the "iff" print_mode, the default is
  2622 "A = B" (with priority 50).
  2623 
  2624 * Relations less (<) and less_eq (<=) are also available on type bool.
  2625 Modified syntax to disallow nesting without explicit parentheses,
  2626 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2627 INCOMPATIBILITY.
  2628 
  2629 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2630 
  2631 * Relation composition operator "op O" now has precedence 75 and binds
  2632 stronger than union and intersection. INCOMPATIBILITY.
  2633 
  2634 * The old set interval syntax "{m..n(}" (and relatives) has been
  2635 removed.  Use "{m..<n}" (and relatives) instead.
  2636 
  2637 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2638 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2639 ``declare [[simproc del: neq]]''.
  2640 
  2641 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2642 True/False.
  2643 
  2644 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2645 
  2646 * Theorem setsum_mult renamed to setsum_right_distrib.
  2647 
  2648 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2649 ``rule'' method.
  2650 
  2651 * Reimplemented methods "sat" and "satx", with several improvements:
  2652 goals no longer need to be stated as "<prems> ==> False", equivalences
  2653 (i.e. "=" on type bool) are handled, variable names of the form
  2654 "lit_<n>" are no longer reserved, significant speedup.
  2655 
  2656 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2657 zChaff is still supported as well.
  2658 
  2659 * 'inductive' and 'datatype': provide projections of mutual rules,
  2660 bundled as foo_bar.inducts;
  2661 
  2662 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2663 Library.
  2664 
  2665 * Library: moved theory Accessible_Part to main HOL.
  2666 
  2667 * Library: added theory Coinductive_List of potentially infinite lists
  2668 as greatest fixed-point.
  2669 
  2670 * Library: added theory AssocList which implements (finite) maps as
  2671 association lists.
  2672 
  2673 * Method "evaluation" solves goals (i.e. a boolean expression)
  2674 efficiently by compiling it to ML.  The goal is "proved" (via an
  2675 oracle) if it evaluates to True.
  2676 
  2677 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2678 also when invoked by the simplifier.  This results in the Simplifier
  2679 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2680 Configuration option fast_arith_split_limit=0 recovers the old
  2681 behavior.
  2682 
  2683 * Support for hex (0x20) and binary (0b1001) numerals.
  2684 
  2685 * New method: reify eqs (t), where eqs are equations for an
  2686 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2687 parameter, computes a term s::'b and a list xs::'a list and proves the
  2688 theorem I xs s = t. This is also known as reification or quoting. The
  2689 resulting theorem is applied to the subgoal to substitute t with I xs
  2690 s.  If t is omitted, the subgoal itself is reified.
  2691 
  2692 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2693 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2694 where f is supposed to be a computable function (in the sense of code
  2695 generattion). The method uses reify to compute s and xs as above then
  2696 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2697 r and finally gets the theorem t = r, which is again applied to the
  2698 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2699 
  2700 * Reflection: Automatic reification now handels binding, an example is
  2701 available in src/HOL/ex/ReflectionEx.thy
  2702 
  2703 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2704 command 'statespace' that is similar to 'record', but introduces an
  2705 abstract specification based on the locale infrastructure instead of
  2706 HOL types.  This leads to extra flexibility in composing state spaces,
  2707 in particular multiple inheritance and renaming of components.
  2708 
  2709 
  2710 *** HOL-Complex ***
  2711 
  2712 * Hyperreal: Functions root and sqrt are now defined on negative real
  2713 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2714 Nonnegativity side conditions have been removed from many lemmas, so
  2715 that more subgoals may now be solved by simplification; potential
  2716 INCOMPATIBILITY.
  2717 
  2718 * Real: new type classes formalize real normed vector spaces and
  2719 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2720 and norm :: 'a => real.
  2721 
  2722 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2723 reals into other types. The overloaded constant Reals :: 'a set is now
  2724 defined as range of_real; potential INCOMPATIBILITY.
  2725 
  2726 * Real: proper support for ML code generation, including 'quickcheck'.
  2727 Reals are implemented as arbitrary precision rationals.
  2728 
  2729 * Hyperreal: Several constants that previously worked only for the
  2730 reals have been generalized, so they now work over arbitrary vector
  2731 spaces. Type annotations may need to be added in some cases; potential
  2732 INCOMPATIBILITY.
  2733 
  2734   Infinitesimal  :: ('a::real_normed_vector) star set
  2735   HFinite        :: ('a::real_normed_vector) star set
  2736   HInfinite      :: ('a::real_normed_vector) star set
  2737   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2738   monad          :: ('a::real_normed_vector) star => 'a star set
  2739   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2740   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2741   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2742   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2743   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2744   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2745   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2746   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2747   sgn            :: 'a::real_normed_vector => 'a
  2748   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2749 
  2750 * Complex: Some complex-specific constants are now abbreviations for
  2751 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2752 hnorm.  Other constants have been entirely removed in favor of the
  2753 polymorphic versions (INCOMPATIBILITY):
  2754 
  2755   approx        <-- capprox
  2756   HFinite       <-- CFinite
  2757   HInfinite     <-- CInfinite
  2758   Infinitesimal <-- CInfinitesimal
  2759   monad         <-- cmonad
  2760   galaxy        <-- cgalaxy
  2761   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2762   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2763   (ns)deriv     <-- (ns)cderiv
  2764 
  2765 
  2766 *** HOL-Algebra ***
  2767 
  2768 * Formalisation of ideals and the quotient construction over rings.
  2769 
  2770 * Order and lattice theory no longer based on records.
  2771 INCOMPATIBILITY.
  2772 
  2773 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2774 greatest_closed.  INCOMPATIBILITY.
  2775 
  2776 * Method algebra is now set up via an attribute.  For examples see
  2777 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2778 of algebraic structures.
  2779 
  2780 * Renamed theory CRing to Ring.
  2781 
  2782 
  2783 *** HOL-Nominal ***
  2784 
  2785 * Substantial, yet incomplete support for nominal datatypes (binding
  2786 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2787 src/HOL/Nominal/Examples.  Prospective users should consult
  2788 http://isabelle.in.tum.de/nominal/
  2789 
  2790 
  2791 *** ML ***
  2792 
  2793 * ML basics: just one true type int, which coincides with IntInf.int
  2794 (even on SML/NJ).
  2795 
  2796 * ML within Isar: antiquotations allow to embed statically-checked
  2797 formal entities in the source, referring to the context available at
  2798 compile-time.  For example:
  2799 
  2800 ML {* @{sort "{zero,one}"} *}
  2801 ML {* @{typ "'a => 'b"} *}
  2802 ML {* @{term "%x. x"} *}
  2803 ML {* @{prop "x == y"} *}
  2804 ML {* @{ctyp "'a => 'b"} *}
  2805 ML {* @{cterm "%x. x"} *}
  2806 ML {* @{cprop "x == y"} *}
  2807 ML {* @{thm asm_rl} *}
  2808 ML {* @{thms asm_rl} *}
  2809 ML {* @{type_name c} *}
  2810 ML {* @{type_syntax c} *}
  2811 ML {* @{const_name c} *}
  2812 ML {* @{const_syntax c} *}
  2813 ML {* @{context} *}
  2814 ML {* @{theory} *}
  2815 ML {* @{theory Pure} *}
  2816 ML {* @{theory_ref} *}
  2817 ML {* @{theory_ref Pure} *}
  2818 ML {* @{simpset} *}
  2819 ML {* @{claset} *}
  2820 ML {* @{clasimpset} *}
  2821 
  2822 The same works for sources being ``used'' within an Isar context.
  2823 
  2824 * ML in Isar: improved error reporting; extra verbosity with
  2825 ML_Context.trace enabled.
  2826 
  2827 * Pure/General/table.ML: the join operations now works via exceptions
  2828 DUP/SAME instead of type option. This is simpler in simple cases, and
  2829 admits slightly more efficient complex applications.
  2830 
  2831 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2832 use Context.generic instead of just theory.
  2833 
  2834 * Pure: datatype Context.generic joins theory/Proof.context and
  2835 provides some facilities for code that works in either kind of
  2836 context, notably GenericDataFun for uniform theory and proof data.
  2837 
  2838 * Pure: simplified internal attribute type, which is now always
  2839 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2840 local (Proof.context) attributes have been discontinued, while
  2841 minimizing code duplication. Thm.rule_attribute and
  2842 Thm.declaration_attribute build canonical attributes; see also structure
  2843 Context for further operations on Context.generic, notably
  2844 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2845 declarations and definitions.
  2846 
  2847 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2848 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2849 init only required for impure data. INCOMPATIBILITY: empty really need
  2850 to be empty (no dependencies on theory content!)
  2851 
  2852 * Pure/kernel: consts certification ignores sort constraints given in
  2853 signature declarations. (This information is not relevant to the
  2854 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2855 potential INCOMPATIBILITY.
  2856 
  2857 * Pure: axiomatic type classes are now purely definitional, with
  2858 explicit proofs of class axioms and super class relations performed
  2859 internally. See Pure/axclass.ML for the main internal interfaces --
  2860 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2861 AxClass.axiomatize_class/classrel/arity supersede
  2862 Sign.add_classes/classrel/arities.
  2863 
  2864 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2865 global/local versions on theory vs. Proof.context have been
  2866 discontinued; Attrib.syntax and Method.syntax have been adapted
  2867 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2868 attributes, methods, etc.
  2869 
  2870 * Pure: several functions of signature "... -> theory -> theory * ..."
  2871 have been reoriented to "... -> theory -> ... * theory" in order to
  2872 allow natural usage in combination with the ||>, ||>>, |-> and
  2873 fold_map combinators.
  2874 
  2875 * Pure: official theorem names (closed derivations) and additional
  2876 comments (tags) are now strictly separate.  Name hints -- which are
  2877 maintained as tags -- may be attached any time without affecting the
  2878 derivation.
  2879 
  2880 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2881 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2882 achieve the old behaviour.
  2883 
  2884 * Pure: the "Goal" constant is now called "prop", supporting a
  2885 slightly more general idea of ``protecting'' meta-level rule
  2886 statements.
  2887 
  2888 * Pure: Logic.(un)varify only works in a global context, which is now
  2889 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2890 Logic.legacy_(un)varify as temporary workaround.
  2891 
  2892 * Pure: structure Name provides scalable operations for generating
  2893 internal variable names, notably Name.variants etc.  This replaces
  2894 some popular functions from term.ML:
  2895 
  2896   Term.variant		->  Name.variant
  2897   Term.variantlist	->  Name.variant_list
  2898   Term.invent_names	->  Name.invent_list
  2899 
  2900 Note that low-level renaming rarely occurs in new code -- operations
  2901 from structure Variable are used instead (see below).
  2902 
  2903 * Pure: structure Variable provides fundamental operations for proper
  2904 treatment of fixed/schematic variables in a context.  For example,
  2905 Variable.import introduces fixes for schematics of given facts and
  2906 Variable.export reverses the effect (up to renaming) -- this replaces
  2907 various freeze_thaw operations.
  2908 
  2909 * Pure: structure Goal provides simple interfaces for
  2910 init/conclude/finish and tactical prove operations (replacing former
  2911 Tactic.prove).  Goal.prove is the canonical way to prove results
  2912 within a given context; Goal.prove_global is a degraded version for
  2913 theory level goals, including a global Drule.standard.  Note that
  2914 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2915 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2916 in a locale context).
  2917 
  2918 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2919 and type checking (Syntax.check_term etc.), with common combinations
  2920 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2921 which are considered legacy and await removal.
  2922 
  2923 * Pure/Syntax: generic interfaces for type unchecking
  2924 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2925 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2926 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2927 available for convenience, but refer to the very same operations using
  2928 a mere theory instead of a full context.
  2929 
  2930 * Isar: simplified treatment of user-level errors, using exception
  2931 ERROR of string uniformly.  Function error now merely raises ERROR,
  2932 without any side effect on output channels.  The Isar toplevel takes
  2933 care of proper display of ERROR exceptions.  ML code may use plain
  2934 handle/can/try; cat_error may be used to concatenate errors like this:
  2935 
  2936   ... handle ERROR msg => cat_error msg "..."
  2937 
  2938 Toplevel ML code (run directly or through the Isar toplevel) may be
  2939 embedded into the Isar toplevel with exception display/debug like
  2940 this:
  2941 
  2942   Isar.toplevel (fn () => ...)
  2943 
  2944 INCOMPATIBILITY, removed special transform_error facilities, removed
  2945 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  2946 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  2947 -- use plain ERROR instead.
  2948 
  2949 * Isar: theory setup now has type (theory -> theory), instead of a
  2950 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  2951 
  2952 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  2953 ProofContext.debug/verbose flags.
  2954 
  2955 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  2956 theory before entering a proof state.  Transactions now always see a
  2957 quasi-functional intermediate checkpoint, both in interactive and
  2958 batch mode.
  2959 
  2960 * Isar: simplified interfaces for outer syntax.  Renamed
  2961 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  2962 OuterSyntax.add_parsers -- this functionality is now included in
  2963 OuterSyntax.command etc.  INCOMPATIBILITY.
  2964 
  2965 * Simplifier: the simpset of a running simplification process now
  2966 contains a proof context (cf. Simplifier.the_context), which is the
  2967 very context that the initial simpset has been retrieved from (by
  2968 simpset_of/local_simpset_of).  Consequently, all plug-in components
  2969 (solver, looper etc.) may depend on arbitrary proof data.
  2970 
  2971 * Simplifier.inherit_context inherits the proof context (plus the
  2972 local bounds) of the current simplification process; any simproc
  2973 etc. that calls the Simplifier recursively should do this!  Removed
  2974 former Simplifier.inherit_bounds, which is already included here --
  2975 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  2976 specify an explicit context using Simplifier.context/theory_context.
  2977 
  2978 * Simplifier/Classical Reasoner: more abstract interfaces
  2979 change_simpset/claset for modifying the simpset/claset reference of a
  2980 theory; raw versions simpset/claset_ref etc. have been discontinued --
  2981 INCOMPATIBILITY.
  2982 
  2983 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  2984 "Trueprop" etc.
  2985 
  2986 
  2987 *** System ***
  2988 
  2989 * settings: the default heap location within ISABELLE_HOME_USER now
  2990 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  2991 Isabelle installations.
  2992 
  2993 * isabelle-process: option -S (secure mode) disables some critical
  2994 operations, notably runtime compilation and evaluation of ML source
  2995 code.
  2996 
  2997 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  2998 
  2999 * Support for parallel execution, using native multicore support of
  3000 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3001 independent theories, according to the given theory header
  3002 specifications. The maximum number of worker threads is specified via
  3003 usedir option -M or the "max-threads" setting in Proof General. A
  3004 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3005 to 6 on a 8-core machine.  User-code needs to observe certain
  3006 guidelines for thread-safe programming, see appendix A in the Isar
  3007 Implementation manual.
  3008 
  3009 
  3010 
  3011 New in Isabelle2005 (October 2005)
  3012 ----------------------------------
  3013 
  3014 *** General ***
  3015 
  3016 * Theory headers: the new header syntax for Isar theories is
  3017 
  3018   theory <name>
  3019   imports <theory1> ... <theoryN>
  3020   uses <file1> ... <fileM>
  3021   begin
  3022 
  3023 where the 'uses' part is optional.  The previous syntax
  3024 
  3025   theory <name> = <theory1> + ... + <theoryN>:
  3026 
  3027 will disappear in the next release.  Use isatool fixheaders to convert
  3028 existing theory files.  Note that there is no change in ancient
  3029 non-Isar theories now, but these will disappear soon.
  3030 
  3031 * Theory loader: parent theories can now also be referred to via
  3032 relative and absolute paths.
  3033 
  3034 * Command 'find_theorems' searches for a list of criteria instead of a
  3035 list of constants. Known criteria are: intro, elim, dest, name:string,
  3036 simp:term, and any term. Criteria can be preceded by '-' to select
  3037 theorems that do not match. Intro, elim, dest select theorems that
  3038 match the current goal, name:s selects theorems whose fully qualified
  3039 name contain s, and simp:term selects all simplification rules whose
  3040 lhs match term.  Any other term is interpreted as pattern and selects
  3041 all theorems matching the pattern. Available in ProofGeneral under
  3042 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3043 
  3044   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3045 
  3046 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3047 matching the current goal as introduction rule and not having "HOL."
  3048 in their name (i.e. not being defined in theory HOL).
  3049 
  3050 * Command 'thms_containing' has been discontinued in favour of
  3051 'find_theorems'; INCOMPATIBILITY.
  3052 
  3053 * Communication with Proof General is now 8bit clean, which means that
  3054 Unicode text in UTF-8 encoding may be used within theory texts (both
  3055 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3056 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3057 
  3058   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3059   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3060 
  3061 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3062 Classical Reasoner.  Typical big applications run around 2 times
  3063 faster.
  3064 
  3065 
  3066 *** Document preparation ***
  3067 
  3068 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3069 of raw sources.  Only those symbols that do not require additional
  3070 LaTeX packages (depending on comments in isabellesym.sty) are
  3071 displayed properly, everything else is left verbatim.  isatool display
  3072 and isatool print are used as front ends (these are subject to the
  3073 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3074 
  3075 * Command tags control specific markup of certain regions of text,
  3076 notably folding and hiding.  Predefined tags include "theory" (for
  3077 theory begin and end), "proof" for proof commands, and "ML" for
  3078 commands involving ML code; the additional tags "visible" and
  3079 "invisible" are unused by default.  Users may give explicit tag
  3080 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3081 interpretation of tags is determined by the LaTeX job during document
  3082 preparation: see option -V of isatool usedir, or options -n and -t of
  3083 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3084 \isadroptag.
  3085 
  3086 Several document versions may be produced at the same time via isatool
  3087 usedir (the generated index.html will link all of them).  Typical
  3088 specifications include ''-V document=theory,proof,ML'' to present
  3089 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3090 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3091 these parts without any formal replacement text.  The Isabelle site
  3092 default settings produce ''document'' and ''outline'' versions as
  3093 specified above.
  3094 
  3095 * Several new antiquotations:
  3096 
  3097   @{term_type term} prints a term with its type annotated;
  3098 
  3099   @{typeof term} prints the type of a term;
  3100 
  3101   @{const const} is the same as @{term const}, but checks that the
  3102   argument is a known logical constant;
  3103 
  3104   @{term_style style term} and @{thm_style style thm} print a term or
  3105   theorem applying a "style" to it
  3106 
  3107   @{ML text}
  3108 
  3109 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3110 definitions, equations, inequations etc., 'concl' printing only the
  3111 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3112 to print the specified premise.  TermStyle.add_style provides an ML
  3113 interface for introducing further styles.  See also the "LaTeX Sugar"
  3114 document practical applications.  The ML antiquotation prints
  3115 type-checked ML expressions verbatim.
  3116 
  3117 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3118 and 'text' support optional locale specification '(in loc)', which
  3119 specifies the default context for interpreting antiquotations.  For
  3120 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3121 
  3122 * Option 'locale=NAME' of antiquotations specifies an alternative
  3123 context interpreting the subsequent argument.  For example: @{thm
  3124 [locale=lattice] inf_assoc}.
  3125 
  3126 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3127 a proof context.
  3128 
  3129 * Proper output of antiquotations for theory commands involving a
  3130 proof context (such as 'locale' or 'theorem (in loc) ...').
  3131 
  3132 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3133 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3134 
  3135 * isatool usedir: new option -C (default true) controls whether option
  3136 -D should include a copy of the original document directory; -C false
  3137 prevents unwanted effects such as copying of administrative CVS data.
  3138 
  3139 
  3140 *** Pure ***
  3141 
  3142 * Considerably improved version of 'constdefs' command.  Now performs
  3143 automatic type-inference of declared constants; additional support for
  3144 local structure declarations (cf. locales and HOL records), see also
  3145 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3146 sequential dependencies of definitions within a single 'constdefs'
  3147 section; moreover, the declared name needs to be an identifier.  If
  3148 all fails, consider to fall back on 'consts' and 'defs' separately.
  3149 
  3150 * Improved indexed syntax and implicit structures.  First of all,
  3151 indexed syntax provides a notational device for subscripted
  3152 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3153 expressions.  Secondly, in a local context with structure
  3154 declarations, number indexes \<^sub>n or the empty index (default
  3155 number 1) refer to a certain fixed variable implicitly; option
  3156 show_structs controls printing of implicit structures.  Typical
  3157 applications of these concepts involve record types and locales.
  3158 
  3159 * New command 'no_syntax' removes grammar declarations (and
  3160 translations) resulting from the given syntax specification, which is
  3161 interpreted in the same manner as for the 'syntax' command.
  3162 
  3163 * 'Advanced' translation functions (parse_translation etc.) may depend
  3164 on the signature of the theory context being presently used for
  3165 parsing/printing, see also isar-ref manual.
  3166 
  3167 * Improved 'oracle' command provides a type-safe interface to turn an
  3168 ML expression of type theory -> T -> term into a primitive rule of
  3169 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3170 is already included here); see also FOL/ex/IffExample.thy;
  3171 INCOMPATIBILITY.
  3172 
  3173 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3174 before); "cI" is no longer bound, use "c.intro" instead.
  3175 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3176 axclasses vs. locales.
  3177 
  3178 * Improved internal renaming of symbolic identifiers -- attach primes
  3179 instead of base 26 numbers.
  3180 
  3181 * New flag show_question_marks controls printing of leading question
  3182 marks in schematic variable names.
  3183 
  3184 * In schematic variable names, *any* symbol following \<^isub> or
  3185 \<^isup> is now treated as part of the base name.  For example, the
  3186 following works without printing of awkward ".0" indexes:
  3187 
  3188   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3189     by simp
  3190 
  3191 * Inner syntax includes (*(*nested*) comments*).
  3192 
  3193 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3194 annotations as "(00...)".
  3195 
  3196 * Clear separation of logical types and nonterminals, where the latter
  3197 may only occur in 'syntax' specifications or type abbreviations.
  3198 Before that distinction was only partially implemented via type class
  3199 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3200 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3201 exotic syntax specifications may require further adaption
  3202 (e.g. Cube/Cube.thy).
  3203 
  3204 * Removed obsolete type class "logic", use the top sort {} instead.
  3205 Note that non-logical types should be declared as 'nonterminals'
  3206 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3207 specifications.
  3208 
  3209 * Attributes 'induct' and 'cases': type or set names may now be
  3210 locally fixed variables as well.
  3211 
  3212 * Simplifier: can now control the depth to which conditional rewriting
  3213 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3214 Limit.
  3215 
  3216 * Simplifier: simplification procedures may now take the current
  3217 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3218 interface), which is very useful for calling the Simplifier
  3219 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3220 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3221 low-level mk_simproc no longer applies Logic.varify internally, to
  3222 allow for use in a context of fixed variables.
  3223 
  3224 * thin_tac now works even if the assumption being deleted contains !!
  3225 or ==>.  More generally, erule now works even if the major premise of
  3226 the elimination rule contains !! or ==>.
  3227 
  3228 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3229 
  3230 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3231 from Pure, which contains all common declarations already.  Both
  3232 theories are defined via plain Isabelle/Isar .thy files.
  3233 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3234 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3235 use isatool fixcpure to adapt your theory and ML sources.
  3236 
  3237 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3238 selections of theorems in named facts via index ranges.
  3239 
  3240 * 'print_theorems': in theory mode, really print the difference
  3241 wrt. the last state (works for interactive theory development only),
  3242 in proof mode print all local facts (cf. 'print_facts');
  3243 
  3244 * 'hide': option '(open)' hides only base names.
  3245 
  3246 * More efficient treatment of intermediate checkpoints in interactive
  3247 theory development.
  3248 
  3249 * Code generator is now invoked via code_module (incremental code
  3250 generation) and code_library (modular code generation, ML structures
  3251 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3252 must be quoted when used as identifiers.
  3253 
  3254 * New 'value' command for reading, evaluating and printing terms using
  3255 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3256 quoted when used as identifier.
  3257 
  3258 
  3259 *** Locales ***
  3260 
  3261 * New commands for the interpretation of locale expressions in
  3262 theories (1), locales (2) and proof contexts (3).  These generate
  3263 proof obligations from the expression specification.  After the
  3264 obligations have been discharged, theorems of the expression are added
  3265 to the theory, target locale or proof context.  The synopsis of the
  3266 commands is a follows:
  3267 
  3268   (1) interpretation expr inst
  3269   (2) interpretation target < expr
  3270   (3) interpret expr inst
  3271 
  3272 Interpretation in theories and proof contexts require a parameter
  3273 instantiation of terms from the current context.  This is applied to
  3274 specifications and theorems of the interpreted expression.
  3275 Interpretation in locales only permits parameter renaming through the
  3276 locale expression.  Interpretation is smart in that interpretations
  3277 that are active already do not occur in proof obligations, neither are
  3278 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3279 inspect active interpretations of a particular locale.  For details,
  3280 see the Isar Reference manual.  Examples can be found in
  3281 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3282 
  3283 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3284 'interpret' instead.
  3285 
  3286 * New context element 'constrains' for adding type constraints to
  3287 parameters.
  3288 
  3289 * Context expressions: renaming of parameters with syntax
  3290 redeclaration.
  3291 
  3292 * Locale declaration: 'includes' disallowed.
  3293 
  3294 * Proper static binding of attribute syntax -- i.e. types / terms /
  3295 facts mentioned as arguments are always those of the locale definition
  3296 context, independently of the context of later invocations.  Moreover,
  3297 locale operations (renaming and type / term instantiation) are applied
  3298 to attribute arguments as expected.
  3299 
  3300 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3301 actual attributes; rare situations may require Attrib.attribute to
  3302 embed those attributes into Attrib.src that lack concrete syntax.
  3303 Attribute implementations need to cooperate properly with the static
  3304 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3305 Attrib.XXX_thm etc. already do the right thing without further
  3306 intervention.  Only unusual applications -- such as "where" or "of"
  3307 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3308 on the context and the facts involved -- may have to assign parsed
  3309 values to argument tokens explicitly.
  3310 
  3311 * Changed parameter management in theorem generation for long goal
  3312 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3313 theorem statement in rare situations.
  3314 
  3315 * Locale inspection command 'print_locale' omits notes elements.  Use
  3316 'print_locale!' to have them included in the output.
  3317 
  3318 
  3319 *** Provers ***
  3320 
  3321 * Provers/hypsubst.ML: improved version of the subst method, for
  3322 single-step rewriting: it now works in bound variable contexts. New is
  3323 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3324 rewrite a different subterm than the original subst method, which is
  3325 still available as 'simplesubst'.
  3326 
  3327 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3328 and quasi orders.
  3329 
  3330 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3331 reflexive-transitive closure of relations.
  3332 
  3333 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3334 limit (previously hard-coded with a value of 20) user-definable.
  3335 
  3336 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3337 is peformed already.  Object-logics merely need to finish their
  3338 initial simpset configuration as before.  INCOMPATIBILITY.
  3339 
  3340 
  3341 *** HOL ***
  3342 
  3343 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3344 
  3345   syntax (epsilon)
  3346     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3347 
  3348 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3349 and x-symbol; use option '-m epsilon' to get it actually printed.
  3350 Moreover, the mathematically important symbolic identifier \<epsilon>
  3351 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3352 
  3353 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3354 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3355 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3356 support corresponding Isar calculations.
  3357 
  3358 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3359 instead of ":".
  3360 
  3361 * theory SetInterval: changed the syntax for open intervals:
  3362 
  3363   Old       New
  3364   {..n(}    {..<n}
  3365   {)n..}    {n<..}
  3366   {m..n(}   {m..<n}
  3367   {)m..n}   {m<..n}
  3368   {)m..n(}  {m<..<n}
  3369 
  3370 The old syntax is still supported but will disappear in the next
  3371 release.  For conversion use the following Emacs search and replace
  3372 patterns (these are not perfect but work quite well):
  3373 
  3374   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3375   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3376 
  3377 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3378 equalities in commutative rings; method 'algebra' provides a generic
  3379 interface.
  3380 
  3381 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3382 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3383 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3384 be a tuple pattern.
  3385 
  3386 Some new syntax forms are available:
  3387 
  3388   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3389   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3390   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3391   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3392 
  3393 The latter form "\<Sum>x < k. e" used to be based on a separate
  3394 function "Summation", which has been discontinued.
  3395 
  3396 * theory Finite_Set: in structured induction proofs, the insert case
  3397 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3398 (insert F x)'.
  3399 
  3400 * The 'refute' command has been extended to support a much larger
  3401 fragment of HOL, including axiomatic type classes, constdefs and
  3402 typedefs, inductive datatypes and recursion.
  3403 
  3404 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3405 Requires zChaff with proof generation to be installed.  See
  3406 HOL/ex/SAT_Examples.thy for examples.
  3407 
  3408 * Datatype induction via method 'induct' now preserves the name of the
  3409 induction variable. For example, when proving P(xs::'a list) by
  3410 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3411 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3412 in unstructured proof scripts.
  3413 
  3414 * Reworked implementation of records.  Improved scalability for
  3415 records with many fields, avoiding performance problems for type
  3416 inference. Records are no longer composed of nested field types, but
  3417 of nested extension types. Therefore the record type only grows linear
  3418 in the number of extensions and not in the number of fields.  The
  3419 top-level (users) view on records is preserved.  Potential
  3420 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3421 old record representation. The type generated for a record is called
  3422 <record_name>_ext_type.
  3423 
  3424 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3425 proofs triggered by a record definition or a simproc (if
  3426 quick_and_dirty is enabled).  Definitions of large records can take
  3427 quite long.
  3428 
  3429 New simproc record_upd_simproc for simplification of multiple record
  3430 updates enabled by default.  Moreover, trivial updates are also
  3431 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3432 occasionally, since simplification is more powerful by default.
  3433 
  3434 * typedef: proper support for polymorphic sets, which contain extra
  3435 type-variables in the term.
  3436 
  3437 * Simplifier: automatically reasons about transitivity chains
  3438 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3439 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3440 old proofs break occasionally as simplification may now solve more
  3441 goals than previously.
  3442 
  3443 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3444 present.  Works for all partial orders (class "order"), in particular
  3445 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3446 just like y <= x.
  3447 
  3448 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3449 bound variable or a constant then the let is unfolded.  Otherwise
  3450 first a is simplified to b, and then f b is simplified to g. If
  3451 possible we abstract b from g arriving at "let x = b in h x",
  3452 otherwise we unfold the let and arrive at g.  The simproc can be
  3453 enabled/disabled by the reference use_let_simproc.  Potential
  3454 INCOMPATIBILITY since simplification is more powerful by default.
  3455 
  3456 * Classical reasoning: the meson method now accepts theorems as arguments.
  3457 
  3458 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3459 jobs to provide advice on the provability of subgoals.
  3460 
  3461 * Theory OrderedGroup and Ring_and_Field: various additions and
  3462 improvements to faciliate calculations involving equalities and
  3463 inequalities.
  3464 
  3465 The following theorems have been eliminated or modified
  3466 (INCOMPATIBILITY):
  3467 
  3468   abs_eq             now named abs_of_nonneg
  3469   abs_of_ge_0        now named abs_of_nonneg
  3470   abs_minus_eq       now named abs_of_nonpos
  3471   imp_abs_id         now named abs_of_nonneg
  3472   imp_abs_neg_id     now named abs_of_nonpos
  3473   mult_pos           now named mult_pos_pos
  3474   mult_pos_le        now named mult_nonneg_nonneg
  3475   mult_pos_neg_le    now named mult_nonneg_nonpos
  3476   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3477   mult_neg           now named mult_neg_neg
  3478   mult_neg_le        now named mult_nonpos_nonpos
  3479 
  3480 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3481      
  3482      zero_le_square
  3483      not_square_less_zero 
  3484 
  3485   The following lemmas have been deleted from Real/RealPow:
  3486   
  3487      realpow_zero_zero
  3488      realpow_two
  3489      realpow_less
  3490      zero_le_power
  3491      realpow_two_le
  3492      abs_realpow_two
  3493      realpow_two_abs     
  3494 
  3495 * Theory Parity: added rules for simplifying exponents.
  3496 
  3497 * Theory List:
  3498 
  3499 The following theorems have been eliminated or modified
  3500 (INCOMPATIBILITY):
  3501 
  3502   list_all_Nil       now named list_all.simps(1)
  3503   list_all_Cons      now named list_all.simps(2)
  3504   list_all_conv      now named list_all_iff
  3505   set_mem_eq         now named mem_iff
  3506 
  3507 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3508 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3509 
  3510 
  3511 *** HOL-Complex ***
  3512 
  3513 * Theory RealDef: better support for embedding natural numbers and
  3514 integers in the reals.
  3515 
  3516 The following theorems have been eliminated or modified
  3517 (INCOMPATIBILITY):
  3518 
  3519   exp_ge_add_one_self  now requires no hypotheses
  3520   real_of_int_add      reversed direction of equality (use [symmetric])
  3521   real_of_int_minus    reversed direction of equality (use [symmetric])
  3522   real_of_int_diff     reversed direction of equality (use [symmetric])
  3523   real_of_int_mult     reversed direction of equality (use [symmetric])
  3524 
  3525 * Theory RComplete: expanded support for floor and ceiling functions.
  3526 
  3527 * Theory Ln is new, with properties of the natural logarithm
  3528 
  3529 * Hyperreal: There is a new type constructor "star" for making
  3530 nonstandard types.  The old type names are now type synonyms:
  3531 
  3532   hypreal = real star
  3533   hypnat = nat star
  3534   hcomplex = complex star
  3535 
  3536 * Hyperreal: Many groups of similarly-defined constants have been
  3537 replaced by polymorphic versions (INCOMPATIBILITY):
  3538 
  3539   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3540 
  3541   starset      <-- starsetNat, starsetC
  3542   *s*          <-- *sNat*, *sc*
  3543   starset_n    <-- starsetNat_n, starsetC_n
  3544   *sn*         <-- *sNatn*, *scn*
  3545   InternalSets <-- InternalNatSets, InternalCSets
  3546 
  3547   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3548   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3549   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3550   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3551   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3552 
  3553 * Hyperreal: Many type-specific theorems have been removed in favor of
  3554 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3555 
  3556   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3557   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3558   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3559   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3560   right_minus <-- hypreal_add_minus
  3561   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3562   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3563   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3564   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3565   mult_1_right <-- hcomplex_mult_one_right
  3566   mult_zero_left <-- hcomplex_mult_zero_left
  3567   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3568   right_distrib <-- hypnat_add_mult_distrib2
  3569   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3570   right_inverse <-- hypreal_mult_inverse
  3571   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3572   order_refl <-- {hypreal,hypnat}_le_refl
  3573   order_trans <-- {hypreal,hypnat}_le_trans
  3574   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3575   order_less_le <-- {hypreal,hypnat}_less_le
  3576   linorder_linear <-- {hypreal,hypnat}_le_linear
  3577   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3578   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3579   add_nonneg_nonneg <-- hypreal_le_add_order
  3580 
  3581 * Hyperreal: Separate theorems having to do with type-specific
  3582 versions of constants have been merged into theorems that apply to the
  3583 new polymorphic constants (INCOMPATIBILITY):
  3584 
  3585   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3586   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3587   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3588   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3589   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3590   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3591   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3592   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3593   STAR_diff <-- {STAR,STARC}_diff
  3594   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3595     STARC_hcomplex_of_complex}_image_subset
  3596   starset_n_Un <-- starset{Nat,C}_n_Un
  3597   starset_n_Int <-- starset{Nat,C}_n_Int
  3598   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3599   starset_n_diff <-- starset{Nat,C}_n_diff
  3600   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3601   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3602   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3603   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3604   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3605   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3606   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3607   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3608   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3609   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3610   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3611   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3612   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3613   starfun_diff <-- starfun{C,RC,CR}_diff
  3614   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3615   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3616   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3617   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3618   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3619   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3620   starfun_Id <-- starfunC_Id
  3621   starfun_approx <-- starfun{Nat,CR}_approx
  3622   starfun_capprox <-- starfun{C,RC}_capprox
  3623   starfun_abs <-- starfunNat_rabs
  3624   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3625   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3626   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3627   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3628   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3629   starfun_add_approx <-- starfunCR_add_approx
  3630   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3631   starfun_divide <-- starfun{C,CR,RC}_divide
  3632   starfun_n <-- starfun{Nat,C}_n
  3633   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3634   starfun_n_add <-- starfun{Nat,C}_n_add
  3635   starfun_n_add_minus <-- starfunNat_n_add_minus
  3636   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3637   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3638   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3639 
  3640   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3641   star_n_minus <-- {hypreal,hcomplex}_minus
  3642   star_n_diff <-- {hypreal,hcomplex}_diff
  3643   star_n_mult <-- {hypreal,hcomplex}_mult
  3644   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3645   star_n_le <-- {hypreal,hypnat}_le
  3646   star_n_less <-- {hypreal,hypnat}_less
  3647   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3648   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3649   star_n_abs <-- hypreal_hrabs
  3650   star_n_divide <-- hcomplex_divide
  3651 
  3652   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3653   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3654   star_of_diff <-- hypreal_of_real_diff
  3655   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3656   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3657   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3658   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3659   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3660   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3661   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3662   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3663   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3664   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3665   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3666   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3667   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3668   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3669   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3670   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3671   star_of_power <-- hypreal_of_real_power
  3672   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3673 
  3674 * Hyperreal: new method "transfer" that implements the transfer
  3675 principle of nonstandard analysis. With a subgoal that mentions
  3676 nonstandard types like "'a star", the command "apply transfer"
  3677 replaces it with an equivalent one that mentions only standard types.
  3678 To be successful, all free variables must have standard types; non-
  3679 standard variables must have explicit universal quantifiers.
  3680 
  3681 * Hyperreal: A theory of Taylor series.
  3682 
  3683 
  3684 *** HOLCF ***
  3685 
  3686 * Discontinued special version of 'constdefs' (which used to support
  3687 continuous functions) in favor of the general Pure one with full
  3688 type-inference.
  3689 
  3690 * New simplification procedure for solving continuity conditions; it
  3691 is much faster on terms with many nested lambda abstractions (cubic
  3692 instead of exponential time).
  3693 
  3694 * New syntax for domain package: selector names are now optional.
  3695 Parentheses should be omitted unless argument is lazy, for example:
  3696 
  3697   domain 'a stream = cons "'a" (lazy "'a stream")
  3698 
  3699 * New command 'fixrec' for defining recursive functions with pattern
  3700 matching; defining multiple functions with mutual recursion is also
  3701 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3702 sinr, or any data constructor defined by the domain package. The given
  3703 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3704 syntax and examples.
  3705 
  3706 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3707 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3708 but the proof obligation additionally includes an admissibility
  3709 requirement. The packages generate instances of class cpo or pcpo,
  3710 with continuity and strictness theorems for Rep and Abs.
  3711 
  3712 * HOLCF: Many theorems have been renamed according to a more standard naming
  3713 scheme (INCOMPATIBILITY):
  3714 
  3715   foo_inject:  "foo$x = foo$y ==> x = y"
  3716   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3717   foo_less:    "(foo$x << foo$y) = (x << y)"
  3718   foo_strict:  "foo$UU = UU"
  3719   foo_defined: "... ==> foo$x ~= UU"
  3720   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3721 
  3722 
  3723 *** ZF ***
  3724 
  3725 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3726 including the First Isomorphism Theorem (on quotienting by the kernel
  3727 of a homomorphism).
  3728 
  3729 * ZF/Simplifier: install second copy of type solver that actually
  3730 makes use of TC rules declared to Isar proof contexts (or locales);
  3731 the old version is still required for ML proof scripts.
  3732 
  3733 
  3734 *** Cube ***
  3735 
  3736 * Converted to Isar theory format; use locales instead of axiomatic
  3737 theories.
  3738 
  3739 
  3740 *** ML ***
  3741 
  3742 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3743 for ||>, ||>>, |>>,
  3744 
  3745 * Pure/library.ML no longer defines its own option datatype, but uses
  3746 that of the SML basis, which has constructors NONE and SOME instead of
  3747 None and Some, as well as exception Option.Option instead of OPTION.
  3748 The functions the, if_none, is_some, is_none have been adapted
  3749 accordingly, while Option.map replaces apsome.
  3750 
  3751 * Pure/library.ML: the exception LIST has been given up in favour of
  3752 the standard exceptions Empty and Subscript, as well as
  3753 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3754 superceded by the standard hd and tl functions etc.
  3755 
  3756 A number of basic list functions are no longer exported to the ML
  3757 toplevel, as they are variants of predefined functions.  The following
  3758 suggests how one can translate existing code:
  3759 
  3760     rev_append xs ys = List.revAppend (xs, ys)
  3761     nth_elem (i, xs) = List.nth (xs, i)
  3762     last_elem xs = List.last xs
  3763     flat xss = List.concat xss
  3764     seq fs = List.app fs
  3765     partition P xs = List.partition P xs
  3766     mapfilter f xs = List.mapPartial f xs
  3767 
  3768 * Pure/library.ML: several combinators for linear functional
  3769 transformations, notably reverse application and composition:
  3770 
  3771   x |> f                f #> g
  3772   (x, y) |-> f          f #-> g
  3773 
  3774 * Pure/library.ML: introduced/changed precedence of infix operators:
  3775 
  3776   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3777   infix 2 ?;
  3778   infix 3 o oo ooo oooo;
  3779   infix 4 ~~ upto downto;
  3780 
  3781 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3782 infix operators.
  3783 
  3784 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3785 fold_map support linear functional transformations and nesting.  For
  3786 example:
  3787 
  3788   fold f [x1, ..., xN] y =
  3789     y |> f x1 |> ... |> f xN
  3790 
  3791   (fold o fold) f [xs1, ..., xsN] y =
  3792     y |> fold f xs1 |> ... |> fold f xsN
  3793 
  3794   fold f [x1, ..., xN] =
  3795     f x1 #> ... #> f xN
  3796 
  3797   (fold o fold) f [xs1, ..., xsN] =
  3798     fold f xs1 #> ... #> fold f xsN
  3799 
  3800 * Pure/library.ML: the following selectors on type 'a option are
  3801 available:
  3802 
  3803   the:               'a option -> 'a  (*partial*)
  3804   these:             'a option -> 'a  where 'a = 'b list
  3805   the_default: 'a -> 'a option -> 'a
  3806   the_list:          'a option -> 'a list
  3807 
  3808 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3809 basic operations for association lists, following natural argument
  3810 order; moreover the explicit equality predicate passed here avoids
  3811 potentially expensive polymorphic runtime equality checks.
  3812 The old functions may be expressed as follows:
  3813 
  3814   assoc = uncurry (AList.lookup (op =))
  3815   assocs = these oo AList.lookup (op =)
  3816   overwrite = uncurry (AList.update (op =)) o swap
  3817 
  3818 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3819 
  3820   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3821   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3822 
  3823 replacing make_keylist and keyfilter (occassionally used)
  3824 Naive rewrites:
  3825 
  3826   make_keylist = AList.make
  3827   keyfilter = AList.find (op =)
  3828 
  3829 * eq_fst and eq_snd now take explicit equality parameter, thus
  3830   avoiding eqtypes. Naive rewrites:
  3831 
  3832     eq_fst = eq_fst (op =)
  3833     eq_snd = eq_snd (op =)
  3834 
  3835 * Removed deprecated apl and apr (rarely used).
  3836   Naive rewrites:
  3837 
  3838     apl (n, op) =>>= curry op n
  3839     apr (op, m) =>>= fn n => op (n, m)
  3840 
  3841 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3842 provides a reasonably efficient light-weight implementation of sets as
  3843 lists.
  3844 
  3845 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3846 few new operations; existing lookup and update are now curried to
  3847 follow natural argument order (for use with fold etc.);
  3848 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3849 
  3850 * Pure/General: output via the Isabelle channels of
  3851 writeln/warning/error etc. is now passed through Output.output, with a
  3852 hook for arbitrary transformations depending on the print_mode
  3853 (cf. Output.add_mode -- the first active mode that provides a output
  3854 function wins).  Already formatted output may be embedded into further
  3855 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3856 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3857 accommodate easy composition of diagnostic messages etc.  Programmers
  3858 rarely need to care about Output.output or Output.raw at all, with
  3859 some notable exceptions: Output.output is required when bypassing the
  3860 standard channels (writeln etc.), or in token translations to produce
  3861 properly formatted results; Output.raw is required when capturing
  3862 already output material that will eventually be presented to the user
  3863 a second time.  For the default print mode, both Output.output and
  3864 Output.raw have no effect.
  3865 
  3866 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3867 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3868 cumulative results are displayed at the end of a batch session.
  3869 
  3870 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3871 replaced by File.platform_path and File.shell_path (with appropriate
  3872 hooks).  This provides a clean interface for unusual systems where the
  3873 internal and external process view of file names are different.
  3874 
  3875 * Pure: more efficient orders for basic syntactic entities: added
  3876 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3877 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3878 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3879 orders now -- potential INCOMPATIBILITY for code that depends on a
  3880 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3881 Library.sort_strings on result).
  3882 
  3883 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3884 fold_types traverse types/terms from left to right, observing natural
  3885 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3886 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3887 
  3888 * Pure: name spaces have been refined, with significant changes of the
  3889 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3890 to extern(_table).  The plain name entry path is superceded by a
  3891 general 'naming' context, which also includes the 'policy' to produce
  3892 a fully qualified name and external accesses of a fully qualified
  3893 name; NameSpace.extend is superceded by context dependent
  3894 Sign.declare_name.  Several theory and proof context operations modify
  3895 the naming context.  Especially note Theory.restore_naming and
  3896 ProofContext.restore_naming to get back to a sane state; note that
  3897 Theory.add_path is no longer sufficient to recover from
  3898 Theory.absolute_path in particular.
  3899 
  3900 * Pure: new flags short_names (default false) and unique_names
  3901 (default true) for controlling output of qualified names.  If
  3902 short_names is set, names are printed unqualified.  If unique_names is
  3903 reset, the name prefix is reduced to the minimum required to achieve
  3904 the original result when interning again, even if there is an overlap
  3905 with earlier declarations.
  3906 
  3907 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3908 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3909 (useful for printing error messages).  INCOMPATIBILITY.
  3910 
  3911 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3912 Theory.theory are now identified, referring to the universal
  3913 Context.theory (see Pure/context.ML).  Actual signature and theory
  3914 content is managed as theory data.  The old code and interfaces were
  3915 spread over many files and structures; the new arrangement introduces
  3916 considerable INCOMPATIBILITY to gain more clarity:
  3917 
  3918   Context -- theory management operations (name, identity, inclusion,
  3919     parents, ancestors, merge, etc.), plus generic theory data;
  3920 
  3921   Sign -- logical signature and syntax operations (declaring consts,
  3922     types, etc.), plus certify/read for common entities;
  3923 
  3924   Theory -- logical theory operations (stating axioms, definitions,
  3925     oracles), plus a copy of logical signature operations (consts,
  3926     types, etc.); also a few basic management operations (Theory.copy,
  3927     Theory.merge, etc.)
  3928 
  3929 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3930 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3931 for convenience -- they merely return the theory.
  3932 
  3933 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3934 
  3935 * Pure: the Isar proof context type is already defined early in Pure
  3936 as Context.proof (note that ProofContext.context and Proof.context are
  3937 aliases, where the latter is the preferred name).  This enables other
  3938 Isabelle components to refer to that type even before Isar is present.
  3939 
  3940 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3941 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3942 any of these kinds.  For example, Sign.intern typeK is now
  3943 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3944 Theory.hide_types.  Also note that former
  3945 Theory.hide_classes/types/consts are now
  3946 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  3947 internalize their arguments!  INCOMPATIBILITY.
  3948 
  3949 * Pure: get_thm interface (of PureThy and ProofContext) expects
  3950 datatype thmref (with constructors Name and NameSelection) instead of
  3951 plain string -- INCOMPATIBILITY;
  3952 
  3953 * Pure: cases produced by proof methods specify options, where NONE
  3954 means to remove case bindings -- INCOMPATIBILITY in
  3955 (RAW_)METHOD_CASES.
  3956 
  3957 * Pure: the following operations retrieve axioms or theorems from a
  3958 theory node or theory hierarchy, respectively:
  3959 
  3960   Theory.axioms_of: theory -> (string * term) list
  3961   Theory.all_axioms_of: theory -> (string * term) list
  3962   PureThy.thms_of: theory -> (string * thm) list
  3963   PureThy.all_thms_of: theory -> (string * thm) list
  3964 
  3965 * Pure: print_tac now outputs the goal through the trace channel.
  3966 
  3967 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  3968 Reference Toplevel.debug (default false) controls detailed printing
  3969 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  3970 controls execution profiling -- set to 1 for time and 2 for space
  3971 (both increase the runtime).
  3972 
  3973 * Isar session: The initial use of ROOT.ML is now always timed,
  3974 i.e. the log will show the actual process times, in contrast to the
  3975 elapsed wall-clock time that the outer shell wrapper produces.
  3976 
  3977 * Simplifier: improved handling of bound variables (nameless
  3978 representation, avoid allocating new strings).  Simprocs that invoke
  3979 the Simplifier recursively should use Simplifier.inherit_bounds to
  3980 avoid local name clashes.  Failure to do so produces warnings
  3981 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  3982 for further details.
  3983 
  3984 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  3985 bindings for all theorems stored within a given theory; this may help
  3986 in porting non-Isar theories to Isar ones, while keeping ML proof
  3987 scripts for the time being.
  3988 
  3989 * ML operator HTML.with_charset specifies the charset begin used for
  3990 generated HTML files.  For example:
  3991 
  3992   HTML.with_charset "utf-8" use_thy "Hebrew";
  3993   HTML.with_charset "utf-8" use_thy "Chinese";
  3994 
  3995 
  3996 *** System ***
  3997 
  3998 * Allow symlinks to all proper Isabelle executables (Isabelle,
  3999 isabelle, isatool etc.).
  4000 
  4001 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4002 isatool doc, isatool mkdir, display_drafts etc.).
  4003 
  4004 * isatool usedir: option -f allows specification of the ML file to be
  4005 used by Isabelle; default is ROOT.ML.
  4006 
  4007 * New isatool version outputs the version identifier of the Isabelle
  4008 distribution being used.
  4009 
  4010 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4011 (containing Boolean satisfiability problems) into Isabelle/HOL
  4012 theories.
  4013 
  4014 
  4015 
  4016 New in Isabelle2004 (April 2004)
  4017 --------------------------------
  4018 
  4019 *** General ***
  4020 
  4021 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4022   Replaces linorder.ML.
  4023 
  4024 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4025   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4026   (\<a>...\<z>), are now considered normal letters, and can therefore
  4027   be used anywhere where an ASCII letter (a...zA...Z) has until
  4028   now. COMPATIBILITY: This obviously changes the parsing of some
  4029   terms, especially where a symbol has been used as a binder, say
  4030   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4031   as an identifier.  Fix it by inserting a space around former
  4032   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4033   existing theory and ML files.
  4034 
  4035 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4036 
  4037 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4038   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4039   a normal (but invisible) letter. For multiple letter subscripts repeat
  4040   \<^isub> like this: x\<^isub>1\<^isub>2.
  4041 
  4042 * Pure: There are now sub-/superscripts that can span more than one
  4043   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4044   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4045   superscript. The new control characters are not identifier parts.
  4046 
  4047 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4048   content of "..." to the latex file instead of \isacntrl... . The "..."
  4049   may consist of any printable characters excluding the end bracket >.
  4050 
  4051 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4052   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4053   declare constants "final", which prevents their being given a definition
  4054   later.  It is useful for constants whose behaviour is fixed axiomatically
  4055   rather than definitionally, such as the meta-logic connectives.
  4056 
  4057 * Pure: 'instance' now handles general arities with general sorts
  4058   (i.e. intersections of classes),
  4059 
  4060 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4061   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4062   It can be changed to alter the colors/layout of generated pages.
  4063 
  4064 
  4065 *** Isar ***
  4066 
  4067 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4068   cut_tac, subgoal_tac and thin_tac:
  4069   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4070     locales are no longer forced to write Isar proof scripts.
  4071     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4072     emulations.
  4073   - INCOMPATIBILITY: names of variables to be instantiated may no
  4074     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4075     This is consistent with the instantiation attribute "where".
  4076 
  4077 * Attributes "where" and "of":
  4078   - Now take type variables of instantiated theorem into account when reading
  4079     the instantiation string.  This fixes a bug that caused instantiated
  4080     theorems to have too special types in some circumstances.
  4081   - "where" permits explicit instantiations of type variables.
  4082 
  4083 * Calculation commands "moreover" and "also" no longer interfere with
  4084   current facts ("this"), admitting arbitrary combinations with "then"
  4085   and derived forms.
  4086 
  4087 * Locales:
  4088   - Goal statements involving the context element "includes" no longer
  4089     generate theorems with internal delta predicates (those ending on
  4090     "_axioms") in the premise.
  4091     Resolve particular premise with <locale>.intro to obtain old form.
  4092   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4093     specification and "includes" elements in goal statement.
  4094   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4095     [intro?] and [elim?] (respectively) by default.
  4096   - Experimental command for instantiation of locales in proof contexts:
  4097         instantiate <label>[<attrs>]: <loc>
  4098     Instantiates locale <loc> and adds all its theorems to the current context
  4099     taking into account their attributes.  Label and attrs are optional
  4100     modifiers, like in theorem declarations.  If present, names of
  4101     instantiated theorems are qualified with <label>, and the attributes
  4102     <attrs> are applied after any attributes these theorems might have already.
  4103       If the locale has assumptions, a chained fact of the form
  4104     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4105     are derived.  The command does not support old-style locales declared
  4106     with "locale (open)".
  4107       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4108 
  4109 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4110   (Isar) contexts.
  4111 
  4112 
  4113 *** HOL ***
  4114 
  4115 * Proof import: new image HOL4 contains the imported library from
  4116   the HOL4 system with about 2500 theorems. It is imported by
  4117   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4118   can be used like any other Isabelle image.  See
  4119   HOL/Import/HOL/README for more information.
  4120 
  4121 * Simplifier:
  4122   - Much improved handling of linear and partial orders.
  4123     Reasoners for linear and partial orders are set up for type classes
  4124     "linorder" and "order" respectively, and are added to the default simpset
  4125     as solvers.  This means that the simplifier can build transitivity chains
  4126     to solve goals from the assumptions.
  4127   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4128     of blast or auto after simplification become unnecessary because the goal
  4129     is solved by simplification already.
  4130 
  4131 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4132     all proved in axiomatic type classes for semirings, rings and fields.
  4133 
  4134 * Numerics:
  4135   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4136     now formalized using the Ring_and_Field theory mentioned above.
  4137   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4138     than before, because now they are set up once in a generic manner.
  4139   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4140     Look for the general versions in Ring_and_Field (and Power if they concern
  4141     exponentiation).
  4142 
  4143 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4144 
  4145 * Records:
  4146   - Record types are now by default printed with their type abbreviation
  4147     instead of the list of all field types. This can be configured via
  4148     the reference "print_record_type_abbr".
  4149   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4150     (not enabled by default).
  4151   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4152     EX x. x = sel r to True (not enabled by default).
  4153   - Tactic "record_split_simp_tac" to split and simplify records added.
  4154 
  4155 * 'specification' command added, allowing for definition by
  4156   specification.  There is also an 'ax_specification' command that
  4157   introduces the new constants axiomatically.
  4158 
  4159 * arith(_tac) is now able to generate counterexamples for reals as well.
  4160 
  4161 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4162 
  4163 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4164   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4165 
  4166 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4167   matrix theory to linear programming.
  4168 
  4169 * Unions and Intersections:
  4170   The latex output syntax of UN and INT has been changed
  4171   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4172   i.e. the index formulae has become a subscript.
  4173   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4174 
  4175 * Unions and Intersections over Intervals:
  4176   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4177   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4178   like in normal math, and corresponding versions for < and for intersection.
  4179 
  4180 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4181   lexicographic dictonary ordering has been added as "lexord".
  4182 
  4183 * ML: the legacy theory structures Int and List have been removed. They had
  4184   conflicted with ML Basis Library structures having the same names.
  4185 
  4186 * 'refute' command added to search for (finite) countermodels.  Only works
  4187   for a fragment of HOL.  The installation of an external SAT solver is
  4188   highly recommended.  See "HOL/Refute.thy" for details.
  4189 
  4190 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4191   formulae under an assignment of free variables to random values.
  4192   In contrast to 'refute', it can deal with inductive datatypes,
  4193   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4194   for examples.
  4195 
  4196 
  4197 *** HOLCF ***
  4198 
  4199 * Streams now come with concatenation and are part of the HOLCF image
  4200 
  4201 
  4202 
  4203 New in Isabelle2003 (May 2003)
  4204 ------------------------------
  4205 
  4206 *** General ***
  4207 
  4208 * Provers/simplifier:
  4209 
  4210   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4211     Assumptions are now subject to complete mutual simplification,
  4212     not just from left to right. The simplifier now preserves
  4213     the order of assumptions.
  4214 
  4215     Potential INCOMPATIBILITY:
  4216 
  4217     -- simp sometimes diverges where the old version did
  4218        not, e.g. invoking simp on the goal
  4219 
  4220         [| P (f x); y = x; f x = f y |] ==> Q
  4221 
  4222        now gives rise to the infinite reduction sequence
  4223 
  4224         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4225 
  4226        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4227        kind of problem.
  4228 
  4229     -- Tactics combining classical reasoner and simplification (such as auto)
  4230        are also affected by this change, because many of them rely on
  4231        simp. They may sometimes diverge as well or yield a different numbers
  4232        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4233        in case of problems. Sometimes subsequent calls to the classical
  4234        reasoner will fail because a preceeding call to the simplifier too
  4235        eagerly simplified the goal, e.g. deleted redundant premises.
  4236 
  4237   - The simplifier trace now shows the names of the applied rewrite rules
  4238 
  4239   - You can limit the number of recursive invocations of the simplifier
  4240     during conditional rewriting (where the simplifie tries to solve the
  4241     conditions before applying the rewrite rule):
  4242     ML "simp_depth_limit := n"
  4243     where n is an integer. Thus you can force termination where previously
  4244     the simplifier would diverge.
  4245 
  4246   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4247 
  4248   - No longer aborts on failed congruence proof.  Instead, the
  4249     congruence is ignored.
  4250 
  4251 * Pure: New generic framework for extracting programs from constructive
  4252   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4253   as HOL/Extraction for some case studies.
  4254 
  4255 * Pure: The main goal of the proof state is no longer shown by default, only
  4256 the subgoals. This behaviour is controlled by a new flag.
  4257    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4258 (ML: Proof.show_main_goal).
  4259 
  4260 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4261 rules whose conclusion matches subgoal 1:
  4262       PG menu: Isabelle/Isar -> Show me -> matching rules
  4263 The rules are ordered by how closely they match the subgoal.
  4264 In particular, rules that solve a subgoal outright are displayed first
  4265 (or rather last, the way they are printed).
  4266 (ML: ProofGeneral.print_intros())
  4267 
  4268 * Pure: New flag trace_unify_fail causes unification to print
  4269 diagnostic information (PG: in trace buffer) when it fails. This is
  4270 useful for figuring out why single step proofs like rule, erule or
  4271 assumption failed.
  4272 
  4273 * Pure: Locale specifications now produce predicate definitions
  4274 according to the body of text (covering assumptions modulo local
  4275 definitions); predicate "loc_axioms" covers newly introduced text,
  4276 while "loc" is cumulative wrt. all included locale expressions; the
  4277 latter view is presented only on export into the global theory
  4278 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4279 on the old view without predicates;
  4280 
  4281 * Pure: predefined locales "var" and "struct" are useful for sharing
  4282 parameters (as in CASL, for example); just specify something like
  4283 ``var x + var y + struct M'' as import;
  4284 
  4285 * Pure: improved thms_containing: proper indexing of facts instead of
  4286 raw theorems; check validity of results wrt. current name space;
  4287 include local facts of proof configuration (also covers active
  4288 locales), cover fixed variables in index; may use "_" in term
  4289 specification; an optional limit for the number of printed facts may
  4290 be given (the default is 40);
  4291 
  4292 * Pure: disallow duplicate fact bindings within new-style theory files
  4293 (batch-mode only);
  4294 
  4295 * Provers: improved induct method: assumptions introduced by case
  4296 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4297 the goal statement); "foo" still refers to all facts collectively;
  4298 
  4299 * Provers: the function blast.overloaded has been removed: all constants
  4300 are regarded as potentially overloaded, which improves robustness in exchange
  4301 for slight decrease in efficiency;
  4302 
  4303 * Provers/linorder: New generic prover for transitivity reasoning over
  4304 linear orders.  Note: this prover is not efficient!
  4305 
  4306 * Isar: preview of problems to finish 'show' now produce an error
  4307 rather than just a warning (in interactive mode);
  4308 
  4309 
  4310 *** HOL ***
  4311 
  4312 * arith(_tac)
  4313 
  4314  - Produces a counter example if it cannot prove a goal.
  4315    Note that the counter example may be spurious if the goal is not a formula
  4316    of quantifier-free linear arithmetic.
  4317    In ProofGeneral the counter example appears in the trace buffer.
  4318 
  4319  - Knows about div k and mod k where k is a numeral of type nat or int.
  4320 
  4321  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4322    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4323    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4324 
  4325 * simp's arithmetic capabilities have been enhanced a bit: it now
  4326 takes ~= in premises into account (by performing a case split);
  4327 
  4328 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4329 are distributed over a sum of terms;
  4330 
  4331 * New tactic "trans_tac" and method "trans" instantiate
  4332 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4333 "<=", "<" and "=").
  4334 
  4335 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4336 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4337 
  4338 * 'typedef' command has new option "open" to suppress the set
  4339 definition;
  4340 
  4341 * functions Min and Max on finite sets have been introduced (theory
  4342 Finite_Set);
  4343 
  4344 * attribute [symmetric] now works for relations as well; it turns
  4345 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4346 
  4347 * induct over a !!-quantified statement (say !!x1..xn):
  4348   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4349 
  4350 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4351 %x. None. Warning: empty_def now refers to the previously hidden definition
  4352 of the empty set.
  4353 
  4354 * Algebra: formalization of classical algebra.  Intended as base for
  4355 any algebraic development in Isabelle.  Currently covers group theory
  4356 (up to Sylow's theorem) and ring theory (Universal Property of
  4357 Univariate Polynomials).  Contributions welcome;
  4358 
  4359 * GroupTheory: deleted, since its material has been moved to Algebra;
  4360 
  4361 * Complex: new directory of the complex numbers with numeric constants,
  4362 nonstandard complex numbers, and some complex analysis, standard and
  4363 nonstandard (Jacques Fleuriot);
  4364 
  4365 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4366 
  4367 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4368 Fleuriot);
  4369 
  4370 * Real/HahnBanach: updated and adapted to locales;
  4371 
  4372 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4373 Gray and Kramer);
  4374 
  4375 * UNITY: added the Meier-Sanders theory of progress sets;
  4376 
  4377 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4378 as abstract algorithms, instantiated to the JVM;
  4379 
  4380 * Bali: Java source language formalization. Type system, operational
  4381 semantics, axiomatic semantics. Supported language features:
  4382 classes, interfaces, objects,virtual methods, static methods,
  4383 static/instance fields, arrays, access modifiers, definite
  4384 assignment, exceptions.
  4385 
  4386 
  4387 *** ZF ***
  4388 
  4389 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4390 universe, etc.);
  4391 
  4392 * Main ZF: virtually all theories converted to new-style format;
  4393 
  4394 
  4395 *** ML ***
  4396 
  4397 * Pure: Tactic.prove provides sane interface for internal proofs;
  4398 omits the infamous "standard" operation, so this is more appropriate
  4399 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4400 
  4401 * Pure: improved error reporting of simprocs;
  4402 
  4403 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4404 up simprocs;
  4405 
  4406 
  4407 *** Document preparation ***
  4408 
  4409 * uses \par instead of \\ for line breaks in theory text. This may
  4410 shift some page breaks in large documents. To get the old behaviour
  4411 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4412 
  4413 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4414 other packages
  4415 
  4416 * \<euro> now needs package babel/greek instead of marvosym (which
  4417 broke \Rightarrow)
  4418 
  4419 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4420 textcomp package)
  4421 
  4422 
  4423 
  4424 New in Isabelle2002 (March 2002)
  4425 --------------------------------
  4426 
  4427 *** Document preparation ***
  4428 
  4429 * greatly simplified document preparation setup, including more
  4430 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4431 instructive isatool mkdir; users should basically be able to get
  4432 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4433 users may run a separate document processing stage manually like this:
  4434 "isatool usedir -D output HOL Test && isatool document Test/output";
  4435 
  4436 * theory dependency graph may now be incorporated into documents;
  4437 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4438 with \includegraphics of LaTeX;
  4439 
  4440 * proper spacing of consecutive markup elements, especially text
  4441 blocks after section headings;
  4442 
  4443 * support bold style (for single symbols only), input syntax is like
  4444 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4445 
  4446 * \<bullet> is now output as bold \cdot by default, which looks much
  4447 better in printed text;
  4448 
  4449 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4450 note that these symbols are currently unavailable in Proof General /
  4451 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4452 
  4453 * isatool latex no longer depends on changed TEXINPUTS, instead
  4454 isatool document copies the Isabelle style files to the target
  4455 location;
  4456 
  4457 
  4458 *** Isar ***
  4459 
  4460 * Pure/Provers: improved proof by cases and induction;
  4461   - 'case' command admits impromptu naming of parameters (such as
  4462     "case (Suc n)");
  4463   - 'induct' method divinates rule instantiation from the inductive
  4464     claim; no longer requires excessive ?P bindings for proper
  4465     instantiation of cases;
  4466   - 'induct' method properly enumerates all possibilities of set/type
  4467     rules; as a consequence facts may be also passed through *type*
  4468     rules without further ado;
  4469   - 'induct' method now derives symbolic cases from the *rulified*
  4470     rule (before it used to rulify cases stemming from the internal
  4471     atomized version); this means that the context of a non-atomic
  4472     statement becomes is included in the hypothesis, avoiding the
  4473     slightly cumbersome show "PROP ?case" form;
  4474   - 'induct' may now use elim-style induction rules without chaining
  4475     facts, using ``missing'' premises from the goal state; this allows
  4476     rules stemming from inductive sets to be applied in unstructured
  4477     scripts, while still benefitting from proper handling of non-atomic
  4478     statements; NB: major inductive premises need to be put first, all
  4479     the rest of the goal is passed through the induction;
  4480   - 'induct' proper support for mutual induction involving non-atomic
  4481     rule statements (uses the new concept of simultaneous goals, see
  4482     below);
  4483   - append all possible rule selections, but only use the first
  4484     success (no backtracking);
  4485   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4486   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4487   - added 'print_induct_rules' (covered by help item in recent Proof
  4488     General versions);
  4489   - moved induct/cases attributes to Pure, methods to Provers;
  4490   - generic method setup instantiated for FOL and HOL;
  4491 
  4492 * Pure: support multiple simultaneous goal statements, for example
  4493 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4494 meta-level mechanism, this acts as if several individual goals had
  4495 been stated separately; in particular common proof methods need to be
  4496 repeated in order to cover all claims; note that a single elimination
  4497 step is *not* sufficient to establish the two conjunctions, so this
  4498 fails:
  4499 
  4500   assume "A & B" then have A and B ..   (*".." fails*)
  4501 
  4502 better use "obtain" in situations as above; alternative refer to
  4503 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4504 
  4505 * Pure: proper integration with ``locales''; unlike the original
  4506 version by Florian Kammller, Isar locales package high-level proof
  4507 contexts rather than raw logical ones (e.g. we admit to include
  4508 attributes everywhere); operations on locales include merge and
  4509 rename; support for implicit arguments (``structures''); simultaneous
  4510 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4511 some examples;
  4512 
  4513 * Pure: the following commands have been ``localized'', supporting a
  4514 target locale specification "(in name)": 'lemma', 'theorem',
  4515 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4516 stored both within the locale and at the theory level (exported and
  4517 qualified by the locale name);
  4518 
  4519 * Pure: theory goals may now be specified in ``long'' form, with
  4520 ad-hoc contexts consisting of arbitrary locale elements. for example
  4521 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4522 definitions may be given, too); the result is a meta-level rule with
  4523 the context elements being discharged in the obvious way;
  4524 
  4525 * Pure: new proof command 'using' allows to augment currently used
  4526 facts after a goal statement ('using' is syntactically analogous to
  4527 'apply', but acts on the goal's facts only); this allows chained facts
  4528 to be separated into parts given before and after a claim, as in
  4529 ``from a and b have C using d and e <proof>'';
  4530 
  4531 * Pure: renamed "antecedent" case to "rule_context";
  4532 
  4533 * Pure: new 'judgment' command records explicit information about the
  4534 object-logic embedding (used by several tools internally); no longer
  4535 use hard-wired "Trueprop";
  4536 
  4537 * Pure: added 'corollary' command;
  4538 
  4539 * Pure: fixed 'token_translation' command;
  4540 
  4541 * Pure: removed obsolete 'exported' attribute;
  4542 
  4543 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4544 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4545 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4546 
  4547 * Pure: method 'atomize' presents local goal premises as object-level
  4548 statements (atomic meta-level propositions); setup controlled via
  4549 rewrite rules declarations of 'atomize' attribute; example
  4550 application: 'induct' method with proper rule statements in improper
  4551 proof *scripts*;
  4552 
  4553 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4554 now consider the syntactic context of assumptions, giving a better
  4555 chance to get type-inference of the arguments right (this is
  4556 especially important for locales);
  4557 
  4558 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4559 mode;
  4560 
  4561 * Pure/obtain: the formal conclusion "thesis", being marked as
  4562 ``internal'', may no longer be reference directly in the text;
  4563 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4564 situations;
  4565 
  4566 * Pure: generic 'sym' attribute which declares a rule both as pure
  4567 'elim?' and for the 'symmetric' operation;
  4568 
  4569 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4570 text; the fixed correlation with particular command syntax has been
  4571 discontinued;
  4572 
  4573 * Pure: new method 'rules' is particularly well-suited for proof
  4574 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4575 but often produces more compact proof terms with less detours;
  4576 
  4577 * Pure/Provers/classical: simplified integration with pure rule
  4578 attributes and methods; the classical "intro?/elim?/dest?"
  4579 declarations coincide with the pure ones; the "rule" method no longer
  4580 includes classically swapped intros; "intro" and "elim" methods no
  4581 longer pick rules from the context; also got rid of ML declarations
  4582 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4583 INCOMPATIBILITY;
  4584 
  4585 * Provers/classical: attribute 'swapped' produces classical inversions
  4586 of introduction rules;
  4587 
  4588 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4589 rules instead of full simplifier context; 'iff' attribute handles
  4590 conditional rules;
  4591 
  4592 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4593 
  4594 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4595 "(permissive)" option to recover old behavior;
  4596 
  4597 * HOL: 'inductive' no longer features separate (collective) attributes
  4598 for 'intros' (was found too confusing);
  4599 
  4600 * HOL: properly declared induction rules less_induct and
  4601 wf_induct_rule;
  4602 
  4603 
  4604 *** HOL ***
  4605 
  4606 * HOL: moved over to sane numeral syntax; the new policy is as
  4607 follows:
  4608 
  4609   - 0 and 1 are polymorphic constants, which are defined on any
  4610   numeric type (nat, int, real etc.);
  4611 
  4612   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4613   binary representation internally;
  4614 
  4615   - type nat has special constructor Suc, and generally prefers Suc 0
  4616   over 1::nat and Suc (Suc 0) over 2::nat;
  4617 
  4618 This change may cause significant problems of INCOMPATIBILITY; here
  4619 are some hints on converting existing sources:
  4620 
  4621   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4622   entities, so expressions involving "-" (unary or binary minus) need
  4623   to be spaced properly;
  4624 
  4625   - existing occurrences of "1" may need to be constraint "1::nat" or
  4626   even replaced by Suc 0; similar for old "2";
  4627 
  4628   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4629 
  4630   - remove all special provisions on numerals in proofs;
  4631 
  4632 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4633 representation (depends on bin_arith_simps in the default context);
  4634 
  4635 * HOL: symbolic syntax for x^2 (numeral 2);
  4636 
  4637 * HOL: the class of all HOL types is now called "type" rather than
  4638 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4639 in axclass/classes, instance/arities, and (usually rare) occurrences
  4640 in typings (of consts etc.); internally the class is called
  4641 "HOL.type", ML programs should refer to HOLogic.typeS;
  4642 
  4643 * HOL/record package improvements:
  4644   - new derived operations "fields" to build a partial record section,
  4645     "extend" to promote a fixed record to a record scheme, and
  4646     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4647     declared as simp by default;
  4648   - shared operations ("more", "fields", etc.) now need to be always
  4649     qualified) --- potential INCOMPATIBILITY;
  4650   - removed "make_scheme" operations (use "make" with "extend") --
  4651     INCOMPATIBILITY;
  4652   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4653   - provides cases/induct rules for use with corresponding Isar
  4654     methods (for concrete records, record schemes, concrete more
  4655     parts, and schematic more parts -- in that order);
  4656   - internal definitions directly based on a light-weight abstract
  4657     theory of product types over typedef rather than datatype;
  4658 
  4659 * HOL: generic code generator for generating executable ML code from
  4660 specifications; specific support for HOL constructs such as inductive
  4661 datatypes and sets, as well as recursive functions; can be invoked
  4662 via 'generate_code' theory section;
  4663 
  4664 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4665 
  4666 * HOL: consolidated and renamed several theories.  In particular:
  4667         Ord.thy has been absorbed into HOL.thy
  4668         String.thy has been absorbed into List.thy
  4669 
  4670 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4671 (beware of argument permutation!);
  4672 
  4673 * HOL: linorder_less_split superseded by linorder_cases;
  4674 
  4675 * HOL/List: "nodups" renamed to "distinct";
  4676 
  4677 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4678 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4679   - Ex_def has changed, now need to use some_eq_ex
  4680 
  4681 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4682 in this (rare) case use:
  4683 
  4684   delSWrapper "split_all_tac"
  4685   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4686 
  4687 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4688 MAY FAIL;
  4689 
  4690 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4691 Isabelle's type classes, ^ on functions and relations has too general
  4692 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4693 necessary to attach explicit type constraints;
  4694 
  4695 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4696 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4697 renamed accordingly (eg "compI" -> "rel_compI").
  4698 
  4699 * HOL: syntax translations now work properly with numerals and records
  4700 expressions;
  4701 
  4702 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4703 of "lam" -- INCOMPATIBILITY;
  4704 
  4705 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4706 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4707 renamed "Product_Type.unit";
  4708 
  4709 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4710 
  4711 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4712 the "cases" method);
  4713 
  4714 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4715 Florian Kammller);
  4716 
  4717 * HOL/IMP: updated and converted to new-style theory format; several
  4718 parts turned into readable document, with proper Isar proof texts and
  4719 some explanations (by Gerwin Klein);
  4720 
  4721 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4722 
  4723 * HOL-Hyperreal is now a logic image;
  4724 
  4725 
  4726 *** HOLCF ***
  4727 
  4728 * Isar: consts/constdefs supports mixfix syntax for continuous
  4729 operations;
  4730 
  4731 * Isar: domain package adapted to new-style theory format, e.g. see
  4732 HOLCF/ex/Dnat.thy;
  4733 
  4734 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4735 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4736 lift.induct_tac, always use UU instead of Undef;
  4737 
  4738 * HOLCF/IMP: updated and converted to new-style theory;
  4739 
  4740 
  4741 *** ZF ***
  4742 
  4743 * Isar: proper integration of logic-specific tools and packages,
  4744 including theory commands '(co)inductive', '(co)datatype',
  4745 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4746 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4747 
  4748 * theory Main no longer includes AC; for the Axiom of Choice, base
  4749 your theory on Main_ZFC;
  4750 
  4751 * the integer library now covers quotients and remainders, with many
  4752 laws relating division to addition, multiplication, etc.;
  4753 
  4754 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4755 typeless version of the formalism;
  4756 
  4757 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4758 format;
  4759 
  4760 * ZF/Induct: new directory for examples of inductive definitions,
  4761 including theory Multiset for multiset orderings; converted to
  4762 new-style theory format;
  4763 
  4764 * ZF: many new theorems about lists, ordinals, etc.;
  4765 
  4766 
  4767 *** General ***
  4768 
  4769 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4770 variable proof controls level of detail: 0 = no proofs (only oracle
  4771 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4772 also ref manual for further ML interfaces;
  4773 
  4774 * Pure/axclass: removed obsolete ML interface
  4775 goal_subclass/goal_arity;
  4776 
  4777 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4778 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4779 separate tokens, so expressions involving minus need to be spaced
  4780 properly;
  4781 
  4782 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4783 rather than "infixl" or "infixr";
  4784 
  4785 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4786 sort constraint specifications in type inference; e.g. "x::_::foo"
  4787 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4788 type variable);
  4789 
  4790 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4791 control output of nested => (types); the default behavior is
  4792 "type_brackets";
  4793 
  4794 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4795 tokens into AST constants;
  4796 
  4797 * Pure/syntax: prefer later declarations of translations and print
  4798 translation functions; potential INCOMPATIBILITY: need to reverse
  4799 multiple declarations for same syntax element constant;
  4800 
  4801 * Pure/show_hyps reset by default (in accordance to existing Isar
  4802 practice);
  4803 
  4804 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4805 addSafter;
  4806 
  4807 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4808 as well;
  4809 
  4810 * system: tested support for MacOS X; should be able to get Isabelle +
  4811 Proof General to work in a plain Terminal after installing Poly/ML
  4812 (e.g. from the Isabelle distribution area) and GNU bash alone
  4813 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4814 support requires further installations, e.g. from
  4815 http://fink.sourceforge.net/);
  4816 
  4817 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4818 
  4819 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4820 of 40 MB), cf. ML_OPTIONS;
  4821 
  4822 * system: Proof General keywords specification is now part of the
  4823 Isabelle distribution (see etc/isar-keywords.el);
  4824 
  4825 * system: support for persistent Proof General sessions (refrain from
  4826 outdating all loaded theories on startup); user may create writable
  4827 logic images like this: ``isabelle -q HOL Test'';
  4828 
  4829 * system: smart selection of Isabelle process versus Isabelle
  4830 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4831 run both "isabelle" and "Isabelle" even if file names are badly
  4832 damaged (executable inspects the case of the first letter of its own
  4833 name); added separate "isabelle-process" and "isabelle-interface";
  4834 
  4835 * system: refrain from any attempt at filtering input streams; no
  4836 longer support ``8bit'' encoding of old isabelle font, instead proper
  4837 iso-latin characters may now be used; the related isatools
  4838 "symbolinput" and "nonascii" have disappeared as well;
  4839 
  4840 * system: removed old "xterm" interface (the print modes "xterm" and
  4841 "xterm_color" are still available for direct use in a suitable
  4842 terminal);
  4843 
  4844 
  4845 
  4846 New in Isabelle99-2 (February 2001)
  4847 -----------------------------------
  4848 
  4849 *** Overview of INCOMPATIBILITIES ***
  4850 
  4851 * HOL: please note that theories in the Library and elsewhere often use the
  4852 new-style (Isar) format; to refer to their theorems in an ML script you must
  4853 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4854 
  4855 * HOL: inductive package no longer splits induction rule aggressively,
  4856 but only as far as specified by the introductions given; the old
  4857 format may be recovered via ML function complete_split_rule or attribute
  4858 'split_rule (complete)';
  4859 
  4860 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4861 gfp_Tarski to gfp_unfold;
  4862 
  4863 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4864 
  4865 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4866 relation); infix "^^" has been renamed "``"; infix "``" has been
  4867 renamed "`"; "univalent" has been renamed "single_valued";
  4868 
  4869 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4870 operation;
  4871 
  4872 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4873 
  4874 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4875 
  4876 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4877 consequence, it is no longer monotonic wrt. the local goal context
  4878 (which is now passed through the inductive cases);
  4879 
  4880 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4881 \<gg> to \<ggreater>;
  4882 
  4883 
  4884 *** Document preparation ***
  4885 
  4886 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4887 available: are "it" for near math-mode best-style output, "sl" for
  4888 slanted text style, and "tt" for plain type-writer; if no
  4889 \isabellestyle command is given, output is according to slanted
  4890 type-writer);
  4891 
  4892 * support sub/super scripts (for single symbols only), input syntax is
  4893 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4894 
  4895 * some more standard symbols; see Appendix A of the system manual for
  4896 the complete list of symbols defined in isabellesym.sty;
  4897 
  4898 * improved isabelle style files; more abstract symbol implementation
  4899 (should now use \isamath{...} and \isatext{...} in custom symbol
  4900 definitions);
  4901 
  4902 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4903 state; Note that presentation of goal states does not conform to
  4904 actual human-readable proof documents.  Please do not include goal
  4905 states into document output unless you really know what you are doing!
  4906 
  4907 * proper indentation of antiquoted output with proportional LaTeX
  4908 fonts;
  4909 
  4910 * no_document ML operator temporarily disables LaTeX document
  4911 generation;
  4912 
  4913 * isatool unsymbolize tunes sources for plain ASCII communication;
  4914 
  4915 
  4916 *** Isar ***
  4917 
  4918 * Pure: Isar now suffers initial goal statements to contain unbound
  4919 schematic variables (this does not conform to actual readable proof
  4920 documents, due to unpredictable outcome and non-compositional proof
  4921 checking); users who know what they are doing may use schematic goals
  4922 for Prolog-style synthesis of proven results;
  4923 
  4924 * Pure: assumption method (an implicit finishing) now handles actual
  4925 rules as well;
  4926 
  4927 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4928 initial goal, declare "that" only as Pure intro (only for single
  4929 steps); the "that" rule assumption may now be involved in implicit
  4930 finishing, thus ".." becomes a feasible for trivial obtains;
  4931 
  4932 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4933 instance proofs may be performed by "..";
  4934 
  4935 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4936 statements as well;
  4937 
  4938 * Pure: more robust selection of calculational rules;
  4939 
  4940 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4941 rule (as well as the assumption rule);
  4942 
  4943 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4944 lemmas, using the graph browser tool;
  4945 
  4946 * Pure: predict failure of "show" in interactive mode;
  4947 
  4948 * Pure: 'thms_containing' now takes actual terms as arguments;
  4949 
  4950 * HOL: improved method 'induct' --- now handles non-atomic goals
  4951 (potential INCOMPATIBILITY); tuned error handling;
  4952 
  4953 * HOL: cases and induct rules now provide explicit hints about the
  4954 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  4955 any remaining facts are inserted into the goal verbatim;
  4956 
  4957 * HOL: local contexts (aka cases) may now contain term bindings as
  4958 well; the 'cases' and 'induct' methods new provide a ?case binding for
  4959 the result to be shown in each case;
  4960 
  4961 * HOL: added 'recdef_tc' command;
  4962 
  4963 * isatool convert assists in eliminating legacy ML scripts;
  4964 
  4965 
  4966 *** HOL ***
  4967 
  4968 * HOL/Library: a collection of generic theories to be used together
  4969 with main HOL; the theory loader path already includes this directory
  4970 by default; the following existing theories have been moved here:
  4971 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  4972 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  4973 
  4974 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  4975 modelling and verification task performed in Isabelle/HOL +
  4976 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  4977 
  4978 * HOL/Algebra: special summation operator SUM no longer exists, it has
  4979 been replaced by setsum; infix 'assoc' now has priority 50 (like
  4980 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  4981 'domain', this makes the theory consistent with mathematical
  4982 literature;
  4983 
  4984 * HOL basics: added overloaded operations "inverse" and "divide"
  4985 (infix "/"), syntax for generic "abs" operation, generic summation
  4986 operator \<Sum>;
  4987 
  4988 * HOL/typedef: simplified package, provide more useful rules (see also
  4989 HOL/subset.thy);
  4990 
  4991 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  4992 now expressed as a proper nested rule (old-style tactic scripts may
  4993 require atomize_strip_tac to cope with non-atomic premises);
  4994 
  4995 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  4996 to "split_conv" (old name still available for compatibility);
  4997 
  4998 * HOL: improved concrete syntax for strings (e.g. allows translation
  4999 rules with string literals);
  5000 
  5001 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5002  and Fleuriot's mechanization of analysis, including the transcendental
  5003  functions for the reals;
  5004 
  5005 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5006 
  5007 
  5008 *** CTT ***
  5009 
  5010 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5011 "lam" is displayed as TWO lambda-symbols
  5012 
  5013 * CTT: theory Main now available, containing everything (that is, Bool
  5014 and Arith);
  5015 
  5016 
  5017 *** General ***
  5018 
  5019 * Pure: the Simplifier has been implemented properly as a derived rule
  5020 outside of the actual kernel (at last!); the overall performance
  5021 penalty in practical applications is about 50%, while reliability of
  5022 the Isabelle inference kernel has been greatly improved;
  5023 
  5024 * print modes "brackets" and "no_brackets" control output of nested =>
  5025 (types) and ==> (props); the default behaviour is "brackets";
  5026 
  5027 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5028 as assumptions as well;
  5029 
  5030 * system: support Poly/ML 4.0;
  5031 
  5032 * system: isatool install handles KDE version 1 or 2;
  5033 
  5034 
  5035 
  5036 New in Isabelle99-1 (October 2000)
  5037 ----------------------------------
  5038 
  5039 *** Overview of INCOMPATIBILITIES ***
  5040 
  5041 * HOL: simplification of natural numbers is much changed; to partly
  5042 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5043 issue the following ML commands:
  5044 
  5045   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5046   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5047 
  5048 * HOL: simplification no longer dives into case-expressions; this is
  5049 controlled by "t.weak_case_cong" for each datatype t;
  5050 
  5051 * HOL: nat_less_induct renamed to less_induct;
  5052 
  5053 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5054 fixsome to patch .thy and .ML sources automatically;
  5055 
  5056   select_equality  -> some_equality
  5057   select_eq_Ex     -> some_eq_ex
  5058   selectI2EX       -> someI2_ex
  5059   selectI2         -> someI2
  5060   selectI          -> someI
  5061   select1_equality -> some1_equality
  5062   Eps_sym_eq       -> some_sym_eq_trivial
  5063   Eps_eq           -> some_eq_trivial
  5064 
  5065 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5066 
  5067 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5068 instead);
  5069 
  5070 * HOL: the recursion equations generated by 'recdef' are now called
  5071 f.simps instead of f.rules;
  5072 
  5073 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5074 
  5075 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5076 sometimes be needed;
  5077 
  5078 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5079 
  5080 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5081 
  5082 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5083 product is now "<*>" instead of "Times"; the lexicographic product is
  5084 now "<*lex*>" instead of "**";
  5085 
  5086 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5087 of main HOL, but was unused); better use HOL's datatype package;
  5088 
  5089 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5090 the old syntax may be recovered as follows:
  5091 
  5092   syntax (symbols)
  5093     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5094       (infixl "\\<oplus>" 100)
  5095 
  5096 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5097 
  5098 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5099 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5100 internally;
  5101 
  5102 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5103 changed from A/r to A//r;
  5104 
  5105 * ZF: new treatment of arithmetic (nat & int) may break some old
  5106 proofs;
  5107 
  5108 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5109 rulify -> rule_format, elimify -> elim_format, ...);
  5110 
  5111 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5112 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5113 should have to change intro!! to intro? only); replaced "delrule" by
  5114 "rule del";
  5115 
  5116 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5117 
  5118 * Provers: strengthened force_tac by using new first_best_tac;
  5119 
  5120 * LaTeX document preparation: several changes of isabelle.sty (see
  5121 lib/texinputs);
  5122 
  5123 
  5124 *** Document preparation ***
  5125 
  5126 * formal comments (text blocks etc.) in new-style theories may now
  5127 contain antiquotations of thm/prop/term/typ/text to be presented
  5128 according to latex print mode; concrete syntax is like this:
  5129 @{term[show_types] "f(x) = a + x"};
  5130 
  5131 * isatool mkdir provides easy setup of Isabelle session directories,
  5132 including proper document sources;
  5133 
  5134 * generated LaTeX sources are now deleted after successful run
  5135 (isatool document -c); may retain a copy somewhere else via -D option
  5136 of isatool usedir;
  5137 
  5138 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5139 style files, achieving self-contained LaTeX sources and simplifying
  5140 LaTeX debugging;
  5141 
  5142 * old-style theories now produce (crude) LaTeX output as well;
  5143 
  5144 * browser info session directories are now self-contained (may be put
  5145 on WWW server seperately); improved graphs of nested sessions; removed
  5146 graph for 'all sessions';
  5147 
  5148 * several improvements in isabelle style files; \isabellestyle{it}
  5149 produces fake math mode output; \isamarkupheader is now \section by
  5150 default; see lib/texinputs/isabelle.sty etc.;
  5151 
  5152 
  5153 *** Isar ***
  5154 
  5155 * Isar/Pure: local results and corresponding term bindings are now
  5156 subject to Hindley-Milner polymorphism (similar to ML); this
  5157 accommodates incremental type-inference very nicely;
  5158 
  5159 * Isar/Pure: new derived language element 'obtain' supports
  5160 generalized existence reasoning;
  5161 
  5162 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5163 support accumulation of results, without applying any rules yet;
  5164 useful to collect intermediate results without explicit name
  5165 references, and for use with transitivity rules with more than 2
  5166 premises;
  5167 
  5168 * Isar/Pure: scalable support for case-analysis type proofs: new
  5169 'case' language element refers to local contexts symbolically, as
  5170 produced by certain proof methods; internally, case names are attached
  5171 to theorems as "tags";
  5172 
  5173 * Isar/Pure: theory command 'hide' removes declarations from
  5174 class/type/const name spaces;
  5175 
  5176 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5177 indicate potential overloading;
  5178 
  5179 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5180 
  5181 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5182 "{a,b,c}" instead of {a,b,c};
  5183 
  5184 * Isar/Pure now provides its own version of intro/elim/dest
  5185 attributes; useful for building new logics, but beware of confusion
  5186 with the version in Provers/classical;
  5187 
  5188 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5189 case name 'antecedent';
  5190 
  5191 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5192 to the current context is now done automatically);
  5193 
  5194 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5195 for definining proof methods in ML;
  5196 
  5197 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5198 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5199 most cases, one should have to change intro!! to intro? only);
  5200 replaced "delrule" by "rule del";
  5201 
  5202 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5203 'symmetric' attribute (the latter supercedes [RS sym]);
  5204 
  5205 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5206 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5207 well (including splits);
  5208 
  5209 * Isar/Provers: Simplifier and Classical methods now support all kind
  5210 of modifiers used in the past, including 'cong', 'iff', etc.
  5211 
  5212 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5213 of Simplifier and Classical reasoner);
  5214 
  5215 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5216 now support named cases; major packages (inductive, datatype, primrec,
  5217 recdef) support case names and properly name parameters;
  5218 
  5219 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5220 monotonicity conditions are extracted to be proven at end of
  5221 calculations;
  5222 
  5223 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5224 method anyway;
  5225 
  5226 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5227 split_if split_if_asm; datatype package provides theorems foo.splits =
  5228 foo.split foo.split_asm for each datatype;
  5229 
  5230 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5231 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5232 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5233 use "(cases (simplified))" method in proper proof texts);
  5234 
  5235 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5236 
  5237 * Isar: names of theorems etc. may be natural numbers as well;
  5238 
  5239 * Isar: 'pr' command: optional arguments for goals_limit and
  5240 ProofContext.prems_limit; no longer prints theory contexts, but only
  5241 proof states;
  5242 
  5243 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5244 additional print modes to be specified; e.g. "pr(latex)" will print
  5245 proof state according to the Isabelle LaTeX style;
  5246 
  5247 * Isar: improved support for emulating tactic scripts, including proof
  5248 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5249 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5250 (for HOL datatypes);
  5251 
  5252 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5253 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5254 'proof method scripts' have to be in depth-first order;
  5255 
  5256 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5257 
  5258 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5259 should instead use individual commands for printing items
  5260 (print_commands, print_methods etc.);
  5261 
  5262 * Isar: added 'nothing' --- the empty list of theorems;
  5263 
  5264 
  5265 *** HOL ***
  5266 
  5267 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5268 corresponding virtual machine and a specification of its bytecode
  5269 verifier and a lightweight bytecode verifier, including proofs of
  5270 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5271 Cornelia Pusch (see also the homepage of project Bali at
  5272 http://isabelle.in.tum.de/Bali/);
  5273 
  5274 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5275 Clemens Ballarin;
  5276 
  5277 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5278 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5279 Rasmussen;
  5280 
  5281 * HOL/Lattice: fundamental concepts of lattice theory and order
  5282 structures, including duals, properties of bounds versus algebraic
  5283 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5284 Theorem for complete lattices etc.; may also serve as a demonstration
  5285 for abstract algebraic reasoning using axiomatic type classes, and
  5286 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5287 
  5288 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5289 von Oheimb;
  5290 
  5291 * HOL/IMPP: extension of IMP with local variables and mutually
  5292 recursive procedures, by David von Oheimb;
  5293 
  5294 * HOL/Lambda: converted into new-style theory and document;
  5295 
  5296 * HOL/ex/Multiquote: example of multiple nested quotations and
  5297 anti-quotations -- basically a generalized version of de-Bruijn
  5298 representation; very useful in avoiding lifting of operations;
  5299 
  5300 * HOL/record: added general record equality rule to simpset; fixed
  5301 select-update simplification procedure to handle extended records as
  5302 well; admit "r" as field name;
  5303 
  5304 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5305 other numeric types and also as the identity of groups, rings, etc.;
  5306 
  5307 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5308 Types nat and int belong to this axclass;
  5309 
  5310 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5311    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5312    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5313   two terms #m*u and #n*u are replaced by #(m+n)*u
  5314     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5315   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5316     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5317 
  5318 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5319 powerful prover for predicate logic but knows nothing of clasets; see
  5320 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5321 
  5322 * HOL: new version of "case_tac" subsumes both boolean case split and
  5323 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5324 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5325 
  5326 * HOL: simplification no longer dives into case-expressions: only the
  5327 selector expression is simplified, but not the remaining arms; to
  5328 enable full simplification of case-expressions for datatype t, you may
  5329 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5330 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5331 
  5332 * HOL/recdef: the recursion equations generated by 'recdef' for
  5333 function 'f' are now called f.simps instead of f.rules; if all
  5334 termination conditions are proved automatically, these simplification
  5335 rules are added to the simpset, as in primrec; rules may be named
  5336 individually as well, resulting in a separate list of theorems for
  5337 each equation;
  5338 
  5339 * HOL/While is a new theory that provides a while-combinator. It
  5340 permits the definition of tail-recursive functions without the
  5341 provision of a termination measure. The latter is necessary once the
  5342 invariant proof rule for while is applied.
  5343 
  5344 * HOL: new (overloaded) notation for the set of elements below/above
  5345 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5346 
  5347 * HOL: theorems impI, allI, ballI bound as "strip";
  5348 
  5349 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5350 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5351 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5352 
  5353 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5354 
  5355 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5356 main HOL, but was unused);
  5357 
  5358 * HOL: fewer consts declared as global (e.g. have to refer to
  5359 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5360 
  5361 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5362 in case of overlap with user translations (e.g. judgements over
  5363 tuples); (note that the underlying logical represenation is still
  5364 bogus);
  5365 
  5366 
  5367 *** ZF ***
  5368 
  5369 * ZF: simplification automatically cancels common terms in arithmetic
  5370 expressions over nat and int;
  5371 
  5372 * ZF: new treatment of nat to minimize type-checking: all operators
  5373 coerce their operands to a natural number using the function natify,
  5374 making the algebraic laws unconditional;
  5375 
  5376 * ZF: as above, for int: operators coerce their operands to an integer
  5377 using the function intify;
  5378 
  5379 * ZF: the integer library now contains many of the usual laws for the
  5380 orderings, including $<=, and monotonicity laws for $+ and $*;
  5381 
  5382 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5383 simplification;
  5384 
  5385 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5386 to the simplifier and classical reasoner simultaneously;
  5387 
  5388 
  5389 *** General ***
  5390 
  5391 * Provers: blast_tac now handles actual object-logic rules as
  5392 assumptions; note that auto_tac uses blast_tac internally as well;
  5393 
  5394 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5395 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5396 
  5397 * Provers: delrules now handles destruct rules as well (no longer need
  5398 explicit make_elim);
  5399 
  5400 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5401   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5402 use instead the strong form,
  5403   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5404 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5405 from destruct-rules;
  5406 
  5407 * Provers: Simplifier.easy_setup provides a fast path to basic
  5408 Simplifier setup for new object-logics;
  5409 
  5410 * Pure: AST translation rules no longer require constant head on LHS;
  5411 
  5412 * Pure: improved name spaces: ambiguous output is qualified; support
  5413 for hiding of names;
  5414 
  5415 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5416 XSYMBOL_HOME; no longer need to do manual configuration in most
  5417 situations;
  5418 
  5419 * system: compression of ML heaps images may now be controlled via -c
  5420 option of isabelle and isatool usedir (currently only observed by
  5421 Poly/ML);
  5422 
  5423 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5424 useful for remote X11);
  5425 
  5426 * system: provide TAGS file for Isabelle sources;
  5427 
  5428 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5429 order;
  5430 
  5431 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5432 timing flag supersedes proof_timing and Toplevel.trace;
  5433 
  5434 * ML: new combinators |>> and |>>> for incremental transformations
  5435 with secondary results (e.g. certain theory extensions):
  5436 
  5437 * ML: PureThy.add_defs gets additional argument to indicate potential
  5438 overloading (usually false);
  5439 
  5440 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5441 results;
  5442 
  5443 
  5444 
  5445 New in Isabelle99 (October 1999)
  5446 --------------------------------
  5447 
  5448 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5449 
  5450 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5451 are no longer simplified.  (This allows the simplifier to unfold recursive
  5452 functional programs.)  To restore the old behaviour, declare
  5453 
  5454     Delcongs [if_weak_cong];
  5455 
  5456 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5457 complement;
  5458 
  5459 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5460 
  5461 * HOL/datatype: mutual_induct_tac no longer exists --
  5462   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5463 
  5464 * HOL/typedef: fixed type inference for representing set; type
  5465 arguments now have to occur explicitly on the rhs as type constraints;
  5466 
  5467 * ZF: The con_defs part of an inductive definition may no longer refer
  5468 to constants declared in the same theory;
  5469 
  5470 * HOL, ZF: the function mk_cases, generated by the inductive
  5471 definition package, has lost an argument.  To simplify its result, it
  5472 uses the default simpset instead of a supplied list of theorems.
  5473 
  5474 * HOL/List: the constructors of type list are now Nil and Cons;
  5475 
  5476 * Simplifier: the type of the infix ML functions
  5477         setSSolver addSSolver setSolver addSolver
  5478 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5479 for packaging solvers. A solver is created via
  5480         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5481 where the string argument is only a comment.
  5482 
  5483 
  5484 *** Proof tools ***
  5485 
  5486 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5487 decision procedure for linear arithmetic. Currently it is used for
  5488 types `nat', `int', and `real' in HOL (see below); it can, should and
  5489 will be instantiated for other types and logics as well.
  5490 
  5491 * The simplifier now accepts rewrite rules with flexible heads, eg
  5492      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5493   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5494   matching.
  5495 
  5496 
  5497 *** General ***
  5498 
  5499 * New Isabelle/Isar subsystem provides an alternative to traditional
  5500 tactical theorem proving; together with the ProofGeneral/isar user
  5501 interface it offers an interactive environment for developing human
  5502 readable proof documents (Isar == Intelligible semi-automated
  5503 reasoning); for further information see isatool doc isar-ref,
  5504 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5505 
  5506 * improved and simplified presentation of theories: better HTML markup
  5507 (including colors), graph views in several sizes; isatool usedir now
  5508 provides a proper interface for user theories (via -P option); actual
  5509 document preparation based on (PDF)LaTeX is available as well (for
  5510 new-style theories only); see isatool doc system for more information;
  5511 
  5512 * native support for Proof General, both for classic Isabelle and
  5513 Isabelle/Isar;
  5514 
  5515 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5516 using the graph browser tool;
  5517 
  5518 * Isabelle manuals now also available as PDF;
  5519 
  5520 * theory loader rewritten from scratch (may not be fully
  5521 bug-compatible); old loadpath variable has been replaced by show_path,
  5522 add_path, del_path, reset_path functions; new operations such as
  5523 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5524 isatool doc ref);
  5525 
  5526 * improved isatool install: option -k creates KDE application icon,
  5527 option -p DIR installs standalone binaries;
  5528 
  5529 * added ML_PLATFORM setting (useful for cross-platform installations);
  5530 more robust handling of platform specific ML images for SML/NJ;
  5531 
  5532 * the settings environment is now statically scoped, i.e. it is never
  5533 created again in sub-processes invoked from isabelle, isatool, or
  5534 Isabelle;
  5535 
  5536 * path element specification '~~' refers to '$ISABELLE_HOME';
  5537 
  5538 * in locales, the "assumes" and "defines" parts may be omitted if
  5539 empty;
  5540 
  5541 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5542 long arrows);
  5543 
  5544 * new print_mode "HTML";
  5545 
  5546 * new flag show_tags controls display of tags of theorems (which are
  5547 basically just comments that may be attached by some tools);
  5548 
  5549 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5550 mode and goal output format:
  5551 
  5552 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5553 244c244
  5554 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5555 ---
  5556 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5557 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5558 181c181
  5559 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5560 ---
  5561 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5562 
  5563 * function bind_thms stores lists of theorems (cf. bind_thm);
  5564 
  5565 * new shorthand tactics ftac, eatac, datac, fatac;
  5566 
  5567 * qed (and friends) now accept "" as result name; in that case the
  5568 theorem is not stored, but proper checks and presentation of the
  5569 result still apply;
  5570 
  5571 * theorem database now also indexes constants "Trueprop", "all",
  5572 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5573 
  5574 
  5575 *** HOL ***
  5576 
  5577 ** HOL arithmetic **
  5578 
  5579 * There are now decision procedures for linear arithmetic over nat and
  5580 int:
  5581 
  5582 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5583 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5584 are treated as atomic; subformulae not involving type `nat' or `int'
  5585 are ignored; quantified subformulae are ignored unless they are
  5586 positive universal or negative existential. The tactic has to be
  5587 invoked by hand and can be a little bit slow. In particular, the
  5588 running time is exponential in the number of occurrences of `min' and
  5589 `max', and `-' on `nat'.
  5590 
  5591 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5592 (negated) (in)equalities among the premises and the conclusion into
  5593 account (i.e. no compound formulae) and does not know about `min' and
  5594 `max', and `-' on `nat'. It is fast and is used automatically by the
  5595 simplifier.
  5596 
  5597 NB: At the moment, these decision procedures do not cope with mixed
  5598 nat/int formulae where the two parts interact, such as `m < n ==>
  5599 int(m) < int(n)'.
  5600 
  5601 * HOL/Numeral provides a generic theory of numerals (encoded
  5602 efficiently as bit strings); setup for types nat/int/real is in place;
  5603 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5604 int, existing theories and proof scripts may require a few additional
  5605 type constraints;
  5606 
  5607 * integer division and remainder can now be performed on constant
  5608 arguments;
  5609 
  5610 * many properties of integer multiplication, division and remainder
  5611 are now available;
  5612 
  5613 * An interface to the Stanford Validity Checker (SVC) is available through the
  5614 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5615 are proved automatically.  SVC must be installed separately, and its results
  5616 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5617 invocation of the underlying oracle).  For SVC see
  5618   http://verify.stanford.edu/SVC
  5619 
  5620 * IsaMakefile: the HOL-Real target now builds an actual image;
  5621 
  5622 
  5623 ** HOL misc **
  5624 
  5625 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5626 (in Isabelle/Isar) -- by Gertrud Bauer;
  5627 
  5628 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5629 analysis for assembly languages with subtypes;
  5630 
  5631 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5632 -- avoids syntactic ambiguities and treats state, transition, and
  5633 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5634 changed syntax and (many) tactics;
  5635 
  5636 * HOL/inductive: Now also handles more general introduction rules such
  5637   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5638   theorems are now maintained within the theory (maintained via the
  5639   "mono" attribute);
  5640 
  5641 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5642   (using function types) such as
  5643 
  5644   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5645 
  5646 * HOL/record: record_simproc (part of the default simpset) takes care
  5647 of selectors applied to updated records; record_split_tac is no longer
  5648 part of the default claset; update_defs may now be removed from the
  5649 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5650 
  5651   claset_ref () := claset() addSWrapper record_split_wrapper;
  5652   Delsimprocs [record_simproc]
  5653 
  5654 * HOL/typedef: fixed type inference for representing set; type
  5655 arguments now have to occur explicitly on the rhs as type constraints;
  5656 
  5657 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5658 names rather than an ML expression;
  5659 
  5660 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5661 supplied later.  Program schemes can be defined, such as
  5662     "While B C s = (if B s then While B C (C s) else s)"
  5663 where the well-founded relation can be chosen after B and C have been given.
  5664 
  5665 * HOL/List: the constructors of type list are now Nil and Cons;
  5666 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5667 course, ML tools referring to List.list.op # etc. have to be adapted;
  5668 
  5669 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5670 disabled by default; run isabelle with option -m HOL to get back to
  5671 the original Gordon/HOL-style output;
  5672 
  5673 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5674 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5675 
  5676 * HOL basic syntax simplified (more orthogonal): all variants of
  5677 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5678 Eps operator is provided as well: "SOME x. P[x]";
  5679 
  5680 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5681 
  5682 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5683 thus available for user theories;
  5684 
  5685 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5686 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5687 time;
  5688 
  5689 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5690 several times and then mp;
  5691 
  5692 
  5693 *** LK ***
  5694 
  5695 * the notation <<...>> is now available as a notation for sequences of
  5696 formulas;
  5697 
  5698 * the simplifier is now installed
  5699 
  5700 * the axiom system has been generalized (thanks to Soren Heilmann)
  5701 
  5702 * the classical reasoner now has a default rule database
  5703 
  5704 
  5705 *** ZF ***
  5706 
  5707 * new primrec section allows primitive recursive functions to be given
  5708 directly (as in HOL) over datatypes and the natural numbers;
  5709 
  5710 * new tactics induct_tac and exhaust_tac for induction (or case
  5711 analysis) over datatypes and the natural numbers;
  5712 
  5713 * the datatype declaration of type T now defines the recursor T_rec;
  5714 
  5715 * simplification automatically does freeness reasoning for datatype
  5716 constructors;
  5717 
  5718 * automatic type-inference, with AddTCs command to insert new
  5719 type-checking rules;
  5720 
  5721 * datatype introduction rules are now added as Safe Introduction rules
  5722 to the claset;
  5723 
  5724 * the syntax "if P then x else y" is now available in addition to
  5725 if(P,x,y);
  5726 
  5727 
  5728 *** Internal programming interfaces ***
  5729 
  5730 * tuned simplifier trace output; new flag debug_simp;
  5731 
  5732 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5733 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5734 
  5735 * AxClass.axclass_tac lost the theory argument;
  5736 
  5737 * tuned current_goals_markers semantics: begin / end goal avoids
  5738 printing empty lines;
  5739 
  5740 * removed prs and prs_fn hook, which was broken because it did not
  5741 include \n in its semantics, forcing writeln to add one
  5742 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5743 string -> unit if you really want to output text without newline;
  5744 
  5745 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5746 plain output, interface builders may have to enable 'isabelle_font'
  5747 mode to get Isabelle font glyphs as before;
  5748 
  5749 * refined token_translation interface; INCOMPATIBILITY: output length
  5750 now of type real instead of int;
  5751 
  5752 * theory loader actions may be traced via new ThyInfo.add_hook
  5753 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5754 your own database of information attached to *whole* theories -- as
  5755 opposed to intra-theory data slots offered via TheoryDataFun;
  5756 
  5757 * proper handling of dangling sort hypotheses (at last!);
  5758 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5759 extra sort hypotheses that can be witnessed from the type signature;
  5760 the force_strip_shyps flag is gone, any remaining shyps are simply
  5761 left in the theorem (with a warning issued by strip_shyps_warning);
  5762 
  5763 
  5764 
  5765 New in Isabelle98-1 (October 1998)
  5766 ----------------------------------
  5767 
  5768 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5769 
  5770 * several changes of automated proof tools;
  5771 
  5772 * HOL: major changes to the inductive and datatype packages, including
  5773 some minor incompatibilities of theory syntax;
  5774 
  5775 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5776 called `inj_on';
  5777 
  5778 * HOL: removed duplicate thms in Arith:
  5779   less_imp_add_less  should be replaced by  trans_less_add1
  5780   le_imp_add_le      should be replaced by  trans_le_add1
  5781 
  5782 * HOL: unary minus is now overloaded (new type constraints may be
  5783 required);
  5784 
  5785 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5786 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5787 now taken as an integer constant.
  5788 
  5789 * Pure: ML function 'theory_of' renamed to 'theory';
  5790 
  5791 
  5792 *** Proof tools ***
  5793 
  5794 * Simplifier:
  5795   1. Asm_full_simp_tac is now more aggressive.
  5796      1. It will sometimes reorient premises if that increases their power to
  5797         simplify.
  5798      2. It does no longer proceed strictly from left to right but may also
  5799         rotate premises to achieve further simplification.
  5800      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5801      old Asm_full_simp_tac in that it does not rotate premises.
  5802   2. The simplifier now knows a little bit about nat-arithmetic.
  5803 
  5804 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5805 allows for selected deletion of wrappers, by introduction of names for
  5806 wrapper functionals.  This implies that addbefore, addSbefore,
  5807 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5808 and that adding two tactics with the same name overwrites the first
  5809 one (emitting a warning).
  5810   type wrapper = (int -> tactic) -> (int -> tactic)
  5811   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5812   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5813   delWrapper, delSWrapper: claset *  string            -> claset
  5814   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5815 
  5816 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5817 semantics; addbefore now affects only the unsafe part of step_tac
  5818 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5819 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5820 by Force_tac;
  5821 
  5822 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5823 compWrapper; added safe wrapper (and access functions for it);
  5824 
  5825 * HOL/split_all_tac is now much faster and fails if there is nothing
  5826 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5827 and the names of the automatically generated variables have changed.
  5828 split_all_tac has moved within claset() from unsafe wrappers to safe
  5829 wrappers, which means that !!-bound variables are split much more
  5830 aggressively, and safe_tac and clarify_tac now split such variables.
  5831 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5832 Note: the same holds for record_split_tac, which does the job of
  5833 split_all_tac for record fields.
  5834 
  5835 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5836 permanently to the default simpset using Addsplits just like
  5837 Addsimps. They can be removed via Delsplits just like
  5838 Delsimps. Lower-case versions are also available.
  5839 
  5840 * HOL/Simplifier: The rule split_if is now part of the default
  5841 simpset. This means that the simplifier will eliminate all occurrences
  5842 of if-then-else in the conclusion of a goal. To prevent this, you can
  5843 either remove split_if completely from the default simpset by
  5844 `Delsplits [split_if]' or remove it in a specific call of the
  5845 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5846 other case splitting rules to/from the default simpset: every datatype
  5847 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5848 t is the name of the datatype).
  5849 
  5850 * Classical reasoner / Simplifier combination: new force_tac (and
  5851 derivatives Force_tac, force) combines rewriting and classical
  5852 reasoning (and whatever other tools) similarly to auto_tac, but is
  5853 aimed to solve the given subgoal completely.
  5854 
  5855 
  5856 *** General ***
  5857 
  5858 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5859 and `goalw': the theory is no longer needed as an explicit argument -
  5860 the current theory context is used; assumptions are no longer returned
  5861 at the ML-level unless one of them starts with ==> or !!; it is
  5862 recommended to convert to these new commands using isatool fixgoal
  5863 (backup your sources first!);
  5864 
  5865 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5866 the current theory context, and 'theory' to lookup stored theories;
  5867 
  5868 * new theory section 'locale' for declaring constants, assumptions and
  5869 definitions that have local scope;
  5870 
  5871 * new theory section 'nonterminals' for purely syntactic types;
  5872 
  5873 * new theory section 'setup' for generic ML setup functions
  5874 (e.g. package initialization);
  5875 
  5876 * the distribution now includes Isabelle icons: see
  5877 lib/logo/isabelle-{small,tiny}.xpm;
  5878 
  5879 * isatool install - install binaries with absolute references to
  5880 ISABELLE_HOME/bin;
  5881 
  5882 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5883 
  5884 * print mode 'emacs' reserved for Isamode;
  5885 
  5886 * support multiple print (ast) translations per constant name;
  5887 
  5888 * theorems involving oracles are now printed with a suffixed [!];
  5889 
  5890 
  5891 *** HOL ***
  5892 
  5893 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5894 
  5895 * HOL/inductive package reorganized and improved: now supports mutual
  5896 definitions such as
  5897 
  5898   inductive EVEN ODD
  5899     intrs
  5900       null "0 : EVEN"
  5901       oddI "n : EVEN ==> Suc n : ODD"
  5902       evenI "n : ODD ==> Suc n : EVEN"
  5903 
  5904 new theorem list "elims" contains an elimination rule for each of the
  5905 recursive sets; inductive definitions now handle disjunctive premises
  5906 correctly (also ZF);
  5907 
  5908 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5909 "mutual_induct" no longer exists - the induction rule is always
  5910 contained in "induct";
  5911 
  5912 
  5913 * HOL/datatype package re-implemented and greatly improved: now
  5914 supports mutually recursive datatypes such as
  5915 
  5916   datatype
  5917     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5918             | SUM ('a aexp) ('a aexp)
  5919             | DIFF ('a aexp) ('a aexp)
  5920             | NUM 'a
  5921   and
  5922     'a bexp = LESS ('a aexp) ('a aexp)
  5923             | AND ('a bexp) ('a bexp)
  5924             | OR ('a bexp) ('a bexp)
  5925 
  5926 as well as indirectly recursive datatypes such as
  5927 
  5928   datatype
  5929     ('a, 'b) term = Var 'a
  5930                   | App 'b ((('a, 'b) term) list)
  5931 
  5932 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5933 induction on mutually / indirectly recursive datatypes.
  5934 
  5935 Primrec equations are now stored in theory and can be accessed via
  5936 <function_name>.simps.
  5937 
  5938 INCOMPATIBILITIES:
  5939 
  5940   - Theories using datatypes must now have theory Datatype as an
  5941     ancestor.
  5942   - The specific <typename>.induct_tac no longer exists - use the
  5943     generic induct_tac instead.
  5944   - natE has been renamed to nat.exhaust - use exhaust_tac
  5945     instead of res_inst_tac ... natE. Note that the variable
  5946     names in nat.exhaust differ from the names in natE, this
  5947     may cause some "fragile" proofs to fail.
  5948   - The theorems split_<typename>_case and split_<typename>_case_asm
  5949     have been renamed to <typename>.split and <typename>.split_asm.
  5950   - Since default sorts of type variables are now handled correctly,
  5951     some datatype definitions may have to be annotated with explicit
  5952     sort constraints.
  5953   - Primrec definitions no longer require function name and type
  5954     of recursive argument.
  5955 
  5956 Consider using isatool fixdatatype to adapt your theories and proof
  5957 scripts to the new package (backup your sources first!).
  5958 
  5959 
  5960 * HOL/record package: considerably improved implementation; now
  5961 includes concrete syntax for record types, terms, updates; theorems
  5962 for surjective pairing and splitting !!-bound record variables; proof
  5963 support is as follows:
  5964 
  5965   1) standard conversions (selectors or updates applied to record
  5966 constructor terms) are part of the standard simpset;
  5967 
  5968   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  5969 made part of standard simpset and claset via addIffs;
  5970 
  5971   3) a tactic for record field splitting (record_split_tac) is part of
  5972 the standard claset (addSWrapper);
  5973 
  5974 To get a better idea about these rules you may retrieve them via
  5975 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  5976 the name of your record type.
  5977 
  5978 The split tactic 3) conceptually simplifies by the following rule:
  5979 
  5980   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  5981 
  5982 Thus any record variable that is bound by meta-all will automatically
  5983 blow up into some record constructor term, consequently the
  5984 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  5985 solve record problems automatically.
  5986 
  5987 
  5988 * reorganized the main HOL image: HOL/Integ and String loaded by
  5989 default; theory Main includes everything;
  5990 
  5991 * automatic simplification of integer sums and comparisons, using cancellation;
  5992 
  5993 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  5994 
  5995 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  5996 
  5997 * many new identities for unions, intersections, set difference, etc.;
  5998 
  5999 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  6000 called split_if, split_split, split_sum_case and split_nat_case (to go
  6001 with add/delsplits);
  6002 
  6003 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  6004 (?x::unit) = (); this is made part of the default simpset, which COULD
  6005 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  6006 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  6007 unit_abs_eta_conv is added in order to counter the effect of
  6008 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  6009 %u.f();
  6010 
  6011 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  6012 makes more sense);
  6013 
  6014 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6015   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6016   disjointness reasoning but breaking a few old proofs.
  6017 
  6018 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  6019 to 'converse' from 'inverse' (for compatibility with ZF and some
  6020 literature);
  6021 
  6022 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  6023 the well-founded relation;
  6024 
  6025 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  6026     Compl A.  The "Compl" syntax remains available as input syntax for this
  6027     release ONLY.
  6028 
  6029 * HOL/Update: new theory of function updates:
  6030     f(a:=b) == %x. if x=a then b else f x
  6031 may also be iterated as in f(a:=b,c:=d,...);
  6032 
  6033 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  6034 
  6035 * HOL/List:
  6036   - new function list_update written xs[i:=v] that updates the i-th
  6037     list position. May also be iterated as in xs[i:=a,j:=b,...].
  6038   - new function `upt' written [i..j(] which generates the list
  6039     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  6040     bound write [i..j], which is a shorthand for [i..j+1(].
  6041   - new lexicographic orderings and corresponding wellfoundedness theorems.
  6042 
  6043 * HOL/Arith:
  6044   - removed 'pred' (predecessor) function;
  6045   - generalized some theorems about n-1;
  6046   - many new laws about "div" and "mod";
  6047   - new laws about greatest common divisors (see theory ex/Primes);
  6048 
  6049 * HOL/Relation: renamed the relational operator r^-1 "converse"
  6050 instead of "inverse";
  6051 
  6052 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  6053   of the multiset ordering;
  6054 
  6055 * directory HOL/Real: a construction of the reals using Dedekind cuts
  6056   (not included by default);
  6057 
  6058 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  6059 
  6060 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  6061   programs, i.e. different program variables may have different types.
  6062 
  6063 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6064   [previously, this check worked only if the rewrite rule was unconditional]
  6065   Now rew can involve either definitions or equalities (either == or =).
  6066 
  6067 
  6068 *** ZF ***
  6069 
  6070 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  6071   only the theorems proved on ZF.ML;
  6072 
  6073 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6074   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6075   disjointness reasoning but breaking a few old proofs.
  6076 
  6077 * ZF/Update: new theory of function updates
  6078     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  6079   may also be iterated as in f(a:=b,c:=d,...);
  6080 
  6081 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6082 
  6083 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6084   [previously, this check worked only if the rewrite rule was unconditional]
  6085   Now rew can involve either definitions or equalities (either == or =).
  6086 
  6087 * case_tac provided for compatibility with HOL
  6088     (like the old excluded_middle_tac, but with subgoals swapped)
  6089 
  6090 
  6091 *** Internal programming interfaces ***
  6092 
  6093 * Pure: several new basic modules made available for general use, see
  6094 also src/Pure/README;
  6095 
  6096 * improved the theory data mechanism to support encapsulation (data
  6097 kind name replaced by private Object.kind, acting as authorization
  6098 key); new type-safe user interface via functor TheoryDataFun; generic
  6099 print_data function becomes basically useless;
  6100 
  6101 * removed global_names compatibility flag -- all theory declarations
  6102 are qualified by default;
  6103 
  6104 * module Pure/Syntax now offers quote / antiquote translation
  6105 functions (useful for Hoare logic etc. with implicit dependencies);
  6106 see HOL/ex/Antiquote for an example use;
  6107 
  6108 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  6109 cterm -> thm;
  6110 
  6111 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  6112 subgoal;
  6113 
  6114 * Display.print_goals function moved to Locale.print_goals;
  6115 
  6116 * standard print function for goals supports current_goals_markers
  6117 variable for marking begin of proof, end of proof, start of goal; the
  6118 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  6119 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  6120 for example;
  6121 
  6122 
  6123 
  6124 New in Isabelle98 (January 1998)
  6125 --------------------------------
  6126 
  6127 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6128 
  6129 * changed lexical syntax of terms / types: dots made part of long
  6130 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6131 
  6132 * simpset (and claset) reference variable replaced by functions
  6133 simpset / simpset_ref;
  6134 
  6135 * no longer supports theory aliases (via merge) and non-trivial
  6136 implicit merge of thms' signatures;
  6137 
  6138 * most internal names of constants changed due to qualified names;
  6139 
  6140 * changed Pure/Sequence interface (see Pure/seq.ML);
  6141 
  6142 
  6143 *** General Changes ***
  6144 
  6145 * hierachically structured name spaces (for consts, types, axms, thms
  6146 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6147 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6148 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6149 long_names for fully qualified output names; NOTE: ML programs
  6150 (special tactics, packages etc.) referring to internal names may have
  6151 to be adapted to cope with fully qualified names; in case of severe
  6152 backward campatibility problems try setting 'global_names' at compile
  6153 time to have enrything declared within a flat name space; one may also
  6154 fine tune name declarations in theories via the 'global' and 'local'
  6155 section;
  6156 
  6157 * reimplemented the implicit simpset and claset using the new anytype
  6158 data filed in signatures; references simpset:simpset ref etc. are
  6159 replaced by functions simpset:unit->simpset and
  6160 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6161 to patch your ML files accordingly;
  6162 
  6163 * HTML output now includes theory graph data for display with Java
  6164 applet or isatool browser; data generated automatically via isatool
  6165 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6166 
  6167 * defs may now be conditional; improved rewrite_goals_tac to handle
  6168 conditional equations;
  6169 
  6170 * defs now admits additional type arguments, using TYPE('a) syntax;
  6171 
  6172 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6173 creates a new theory node; implicit merge of thms' signatures is
  6174 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6175 transfer:theory->thm->thm in (rare) cases;
  6176 
  6177 * improved handling of draft signatures / theories; draft thms (and
  6178 ctyps, cterms) are automatically promoted to real ones;
  6179 
  6180 * slightly changed interfaces for oracles: admit many per theory, named
  6181 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6182 
  6183 * print_goals: optional output of const types (set show_consts and
  6184 show_types);
  6185 
  6186 * improved output of warnings (###) and errors (***);
  6187 
  6188 * subgoal_tac displays a warning if the new subgoal has type variables;
  6189 
  6190 * removed old README and Makefiles;
  6191 
  6192 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  6193 
  6194 * removed obsolete init_pps and init_database;
  6195 
  6196 * deleted the obsolete tactical STATE, which was declared by
  6197     fun STATE tacfun st = tacfun st st;
  6198 
  6199 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  6200 (which abbreviates $HOME);
  6201 
  6202 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  6203 use isatool fixseq to adapt your ML programs (this works for fully
  6204 qualified references to the Sequence structure only!);
  6205 
  6206 * use_thy no longer requires writable current directory; it always
  6207 reloads .ML *and* .thy file, if either one is out of date;
  6208 
  6209 
  6210 *** Classical Reasoner ***
  6211 
  6212 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  6213 tactics that use classical reasoning to simplify a subgoal without
  6214 splitting it into several subgoals;
  6215 
  6216 * Safe_tac: like safe_tac but uses the default claset;
  6217 
  6218 
  6219 *** Simplifier ***
  6220 
  6221 * added simplification meta rules:
  6222     (asm_)(full_)simplify: simpset -> thm -> thm;
  6223 
  6224 * simplifier.ML no longer part of Pure -- has to be loaded by object
  6225 logics (again);
  6226 
  6227 * added prems argument to simplification procedures;
  6228 
  6229 * HOL, FOL, ZF: added infix function `addsplits':
  6230   instead of `<simpset> setloop (split_tac <thms>)'
  6231   you can simply write `<simpset> addsplits <thms>'
  6232 
  6233 
  6234 *** Syntax ***
  6235 
  6236 * TYPE('a) syntax for type reflection terms;
  6237 
  6238 * no longer handles consts with name "" -- declare as 'syntax' instead;
  6239 
  6240 * pretty printer: changed order of mixfix annotation preference (again!);
  6241 
  6242 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  6243 
  6244 
  6245 *** HOL ***