NEWS
author wenzelm
Mon Jan 04 11:55:23 2010 +0100 (2010-01-04 ago)
changeset 34238 b28be884edda
parent 34170 254ac75e4c38
child 34255 2dd2547acb41
permissions -rw-r--r--
discontinued special HOL_USEDIR_OPTIONS;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** Pure ***
     8 
     9 * Code generator: details of internal data cache have no impact on
    10 the user space functionality any longer.
    11 
    12 
    13 *** HOL ***
    14 
    15 * Reorganized theory Sum_Type.thy; Inl and Inr now have
    16 authentic syntax.  INCOMPATIBILITY.
    17 
    18 * Code generation: ML and OCaml code is decorated with signatures.
    19 
    20 * Complete_Lattice.thy: lemmas top_def and bot_def have been replaced
    21 by the more convenient lemmas Inf_empty and Sup_empty.  Dropped lemmas
    22 Inf_insert_simp and Sup_insert_simp, which are subsumed by Inf_insert
    23 and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace former Inf_Univ
    24 and Sup_Univ.  Lemmas inf_top_right and sup_bot_right subsume inf_top
    25 and sup_bot respectively.  INCOMPATIBILITY.
    26 
    27 * Finite_Set.thy and List.thy: some lemmas have been generalized from
    28 sets to lattices:
    29 
    30   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
    31   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
    32   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
    33   union_Union_fold_union        ~> sup_Sup_fold_sup
    34   Inter_fold_inter              ~> Inf_fold_inf
    35   Union_fold_union              ~> Sup_fold_sup
    36   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
    37   union_UNION_fold_union        ~> sup_SUPR_fold_sup
    38   INTER_fold_inter              ~> INFI_fold_inf
    39   UNION_fold_union              ~> SUPR_fold_sup
    40 
    41 
    42 *** ML ***
    43 
    44 * Curried take and drop in library.ML; negative length is interpreted
    45 as infinity (as in chop).  INCOMPATIBILITY.
    46 
    47 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
    48 usual for resolution.  Rare INCOMPATIBILITY.
    49 
    50 
    51 *** System ***
    52 
    53 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
    54 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
    55 proof terms are enabled unconditionally in the new HOL-Proofs image.
    56 
    57 
    58 
    59 New in Isabelle2009-1 (December 2009)
    60 -------------------------------------
    61 
    62 *** General ***
    63 
    64 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    65 one backslash should be used, even in ML sources.
    66 
    67 
    68 *** Pure ***
    69 
    70 * Locale interpretation propagates mixins along the locale hierarchy.
    71 The currently only available mixins are the equations used to map
    72 local definitions to terms of the target domain of an interpretation.
    73 
    74 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
    75 loc" to print all interpretations of locale "loc" in the theory.
    76 Interpretations in proofs are not shown.
    77 
    78 * Thoroughly revised locales tutorial.  New section on conditional
    79 interpretation.
    80 
    81 * On instantiation of classes, remaining undefined class parameters
    82 are formally declared.  INCOMPATIBILITY.
    83 
    84 
    85 *** Document preparation ***
    86 
    87 * New generalized style concept for printing terms: @{foo (style) ...}
    88 instead of @{foo_style style ...}  (old form is still retained for
    89 backward compatibility).  Styles can be also applied for
    90 antiquotations prop, term_type and typeof.
    91 
    92 
    93 *** HOL ***
    94 
    95 * New proof method "smt" for a combination of first-order logic with
    96 equality, linear and nonlinear (natural/integer/real) arithmetic, and
    97 fixed-size bitvectors; there is also basic support for higher-order
    98 features (esp. lambda abstractions).  It is an incomplete decision
    99 procedure based on external SMT solvers using the oracle mechanism;
   100 for the SMT solver Z3, this method is proof-producing.  Certificates
   101 are provided to avoid calling the external solvers solely for
   102 re-checking proofs.  Due to a remote SMT service there is no need for
   103 installing SMT solvers locally.  See src/HOL/SMT.
   104 
   105 * New commands to load and prove verification conditions generated by
   106 the Boogie program verifier or derived systems (e.g. the Verifying C
   107 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   108 
   109 * New counterexample generator tool 'nitpick' based on the Kodkod
   110 relational model finder.  See src/HOL/Tools/Nitpick and
   111 src/HOL/Nitpick_Examples.
   112 
   113 * New commands 'code_pred' and 'values' to invoke the predicate
   114 compiler and to enumerate values of inductive predicates.
   115 
   116 * A tabled implementation of the reflexive transitive closure.
   117 
   118 * New implementation of quickcheck uses generic code generator;
   119 default generators are provided for all suitable HOL types, records
   120 and datatypes.  Old quickcheck can be re-activated importing theory
   121 Library/SML_Quickcheck.
   122 
   123 * New testing tool Mirabelle for automated proof tools.  Applies
   124 several tools and tactics like sledgehammer, metis, or quickcheck, to
   125 every proof step in a theory.  To be used in batch mode via the
   126 "mirabelle" utility.
   127 
   128 * New proof method "sos" (sum of squares) for nonlinear real
   129 arithmetic (originally due to John Harison). It requires theory
   130 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   131 works well in practice on quantifier-free real arithmetic with +, -,
   132 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   133 inequalities between polynomials.  It makes use of external
   134 semidefinite programming solvers.  Method "sos" generates a
   135 certificate that can be pasted into the proof thus avoiding the need
   136 to call an external tool every time the proof is checked.  See
   137 src/HOL/Library/Sum_Of_Squares.
   138 
   139 * New method "linarith" invokes existing linear arithmetic decision
   140 procedure only.
   141 
   142 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   143 
   144 * New Sledgehammer option "Full Types" in Proof General settings menu.
   145 Causes full type information to be output to the ATPs.  This slows
   146 ATPs down considerably but eliminates a source of unsound "proofs"
   147 that fail later.
   148 
   149 * New method "metisFT": A version of metis that uses full type
   150 information in order to avoid failures of proof reconstruction.
   151 
   152 * New evaluator "approximate" approximates an real valued term using
   153 the same method as the approximation method.
   154 
   155 * Method "approximate" now supports arithmetic expressions as
   156 boundaries of intervals and implements interval splitting and Taylor
   157 series expansion.
   158 
   159 * ML antiquotation @{code_datatype} inserts definition of a datatype
   160 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   161 
   162 * New theory SupInf of the supremum and infimum operators for sets of
   163 reals.
   164 
   165 * New theory Probability, which contains a development of measure
   166 theory, eventually leading to Lebesgue integration and probability.
   167 
   168 * Extended Multivariate Analysis to include derivation and Brouwer's
   169 fixpoint theorem.
   170 
   171 * Reorganization of number theory, INCOMPATIBILITY:
   172   - new number theory development for nat and int, in theories Divides
   173     and GCD as well as in new session Number_Theory
   174   - some constants and facts now suffixed with _nat and _int
   175     accordingly
   176   - former session NumberTheory now named Old_Number_Theory, including
   177     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   178   - moved theory Pocklington from src/HOL/Library to
   179     src/HOL/Old_Number_Theory
   180 
   181 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   182 lcm of finite and infinite sets. It is shown that they form a complete
   183 lattice.
   184 
   185 * Class semiring_div requires superclass no_zero_divisors and proof of
   186 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   187 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   188 generalized to class semiring_div, subsuming former theorems
   189 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   190 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   191 INCOMPATIBILITY.
   192 
   193 * Refinements to lattice classes and sets:
   194   - less default intro/elim rules in locale variant, more default
   195     intro/elim rules in class variant: more uniformity
   196   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   197     le_inf_iff
   198   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   199     sup_aci)
   200   - renamed ACI to inf_sup_aci
   201   - new class "boolean_algebra"
   202   - class "complete_lattice" moved to separate theory
   203     "Complete_Lattice"; corresponding constants (and abbreviations)
   204     renamed and with authentic syntax:
   205     Set.Inf ~>    Complete_Lattice.Inf
   206     Set.Sup ~>    Complete_Lattice.Sup
   207     Set.INFI ~>   Complete_Lattice.INFI
   208     Set.SUPR ~>   Complete_Lattice.SUPR
   209     Set.Inter ~>  Complete_Lattice.Inter
   210     Set.Union ~>  Complete_Lattice.Union
   211     Set.INTER ~>  Complete_Lattice.INTER
   212     Set.UNION ~>  Complete_Lattice.UNION
   213   - authentic syntax for
   214     Set.Pow
   215     Set.image
   216   - mere abbreviations:
   217     Set.empty               (for bot)
   218     Set.UNIV                (for top)
   219     Set.inter               (for inf, formerly Set.Int)
   220     Set.union               (for sup, formerly Set.Un)
   221     Complete_Lattice.Inter  (for Inf)
   222     Complete_Lattice.Union  (for Sup)
   223     Complete_Lattice.INTER  (for INFI)
   224     Complete_Lattice.UNION  (for SUPR)
   225   - object-logic definitions as far as appropriate
   226 
   227 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   228 Un_subset_iff are explicitly deleted as default simp rules; then also
   229 their lattice counterparts le_inf_iff and le_sup_iff have to be
   230 deleted to achieve the desired effect.
   231 
   232 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   233 rules by default any longer; the same applies to min_max.inf_absorb1
   234 etc.  INCOMPATIBILITY.
   235 
   236 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   237 pred_set_conv by default.  INCOMPATIBILITY.
   238 
   239 * Power operations on relations and functions are now one dedicated
   240 constant "compow" with infix syntax "^^".  Power operation on
   241 multiplicative monoids retains syntax "^" and is now defined generic
   242 in class power.  INCOMPATIBILITY.
   243 
   244 * Relation composition "R O S" now has a more standard argument order:
   245 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   246 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   247 break, since the O_assoc rule was not rewritten like this.  Fix using
   248 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   249 
   250 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   251 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   252 INCOMPATIBILITY.
   253 
   254 * Most rules produced by inductive and datatype package have mandatory
   255 prefixes.  INCOMPATIBILITY.
   256 
   257 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   258 the attribute of the same name.  Each of the theorems in the list
   259 DERIV_intros assumes composition with an additional function and
   260 matches a variable to the derivative, which has to be solved by the
   261 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   262 of most elementary terms.  Former Maclauren.DERIV_tac and
   263 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   264 INCOMPATIBILITY.
   265 
   266 * Code generator attributes follow the usual underscore convention:
   267     code_unfold     replaces    code unfold
   268     code_post       replaces    code post
   269     etc.
   270   INCOMPATIBILITY.
   271 
   272 * Renamed methods:
   273     sizechange -> size_change
   274     induct_scheme -> induction_schema
   275   INCOMPATIBILITY.
   276 
   277 * Discontinued abbreviation "arbitrary" of constant "undefined".
   278 INCOMPATIBILITY, use "undefined" directly.
   279 
   280 * Renamed theorems:
   281     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   282     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   283     Suc_plus1 -> Suc_eq_plus1
   284     *anti_sym -> *antisym*
   285     vector_less_eq_def -> vector_le_def
   286   INCOMPATIBILITY.
   287 
   288 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   289 INCOMPATIBILITY.
   290 
   291 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   292 INCOMPATIBILITY.
   293 
   294 
   295 *** HOLCF ***
   296 
   297 * Theory Representable defines a class "rep" of domains that are
   298 representable (via an ep-pair) in the universal domain type "udom".
   299 Instances are provided for all type constructors defined in HOLCF.
   300 
   301 * The 'new_domain' command is a purely definitional version of the
   302 domain package, for representable domains.  Syntax is identical to the
   303 old domain package.  The 'new_domain' package also supports indirect
   304 recursion using previously-defined type constructors.  See
   305 src/HOLCF/ex/New_Domain.thy for examples.
   306 
   307 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   308 on the left-hand side of an equation, and then performs
   309 simplification.  Rewriting is done using rules declared with the
   310 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   311 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   312 
   313 * The pattern-match compiler in 'fixrec' can now handle constructors
   314 with HOL function types.  Pattern-match combinators for the Pair
   315 constructor are pre-configured.
   316 
   317 * The 'fixrec' package now produces better fixed-point induction rules
   318 for mutually-recursive definitions:  Induction rules have conclusions
   319 of the form "P foo bar" instead of "P <foo, bar>".
   320 
   321 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   322 been renamed to "below".  The name "below" now replaces "less" in many
   323 theorem names.  (Legacy theorem names using "less" are still supported
   324 as well.)
   325 
   326 * The 'fixrec' package now supports "bottom patterns".  Bottom
   327 patterns can be used to generate strictness rules, or to make
   328 functions more strict (much like the bang-patterns supported by the
   329 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   330 examples.
   331 
   332 
   333 *** ML ***
   334 
   335 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   336 errors and run-time exceptions, including detailed source positions.
   337 
   338 * Structure Name_Space (formerly NameSpace) now manages uniquely
   339 identified entries, with some additional information such as source
   340 position, logical grouping etc.
   341 
   342 * Theory and context data is now introduced by the simplified and
   343 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   344 to be pure, but the old TheoryDataFun for mutable data (with explicit
   345 copy operation) is still available for some time.
   346 
   347 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   348 provides a high-level programming interface to synchronized state
   349 variables with atomic update.  This works via pure function
   350 application within a critical section -- its runtime should be as
   351 short as possible; beware of deadlocks if critical code is nested,
   352 either directly or indirectly via other synchronized variables!
   353 
   354 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   355 wraps raw ML references, explicitly indicating their non-thread-safe
   356 behaviour.  The Isar toplevel keeps this structure open, to
   357 accommodate Proof General as well as quick and dirty interactive
   358 experiments with references.
   359 
   360 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   361 parallel tactical reasoning.
   362 
   363 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   364 are similar to SUBPROOF, but are slightly more flexible: only the
   365 specified parts of the subgoal are imported into the context, and the
   366 body tactic may introduce new subgoals and schematic variables.
   367 
   368 * Old tactical METAHYPS, which does not observe the proof context, has
   369 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   370 or Subgoal.FOCUS etc.
   371 
   372 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   373 functors have their own ML name space there is no point to mark them
   374 separately.)  Minor INCOMPATIBILITY.
   375 
   376 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   377 
   378 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   379 INCOMPATIBILITY.
   380 
   381 * Operations of structure Skip_Proof no longer require quick_and_dirty
   382 mode, which avoids critical setmp.
   383 
   384 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   385 combinators for "args".  INCOMPATIBILITY, need to use simplified
   386 Attrib/Method.setup introduced in Isabelle2009.
   387 
   388 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   389 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   390 last resort.  INCOMPATIBILITY.
   391 
   392 * Display.pretty_thm now requires a proper context (cf. former
   393 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   394 or even Display.pretty_thm_without_context as last resort.
   395 INCOMPATIBILITY.
   396 
   397 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   398 Syntax.pretty_typ/term directly, preferably with proper context
   399 instead of global theory.
   400 
   401 
   402 *** System ***
   403 
   404 * Further fine tuning of parallel proof checking, scales up to 8 cores
   405 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   406 usedir option -q.
   407 
   408 * Support for additional "Isabelle components" via etc/components, see
   409 also the system manual.
   410 
   411 * The isabelle makeall tool now operates on all components with
   412 IsaMakefile, not just hardwired "logics".
   413 
   414 * Removed "compress" option from isabelle-process and isabelle usedir;
   415 this is always enabled.
   416 
   417 * Discontinued support for Poly/ML 4.x versions.
   418 
   419 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   420 on a given logic image.  This requires the lighttpd webserver and is
   421 currently supported on Linux only.
   422 
   423 
   424 
   425 New in Isabelle2009 (April 2009)
   426 --------------------------------
   427 
   428 *** General ***
   429 
   430 * Simplified main Isabelle executables, with less surprises on
   431 case-insensitive file-systems (such as Mac OS).
   432 
   433   - The main Isabelle tool wrapper is now called "isabelle" instead of
   434     "isatool."
   435 
   436   - The former "isabelle" alias for "isabelle-process" has been
   437     removed (should rarely occur to regular users).
   438 
   439   - The former "isabelle-interface" and its alias "Isabelle" have been
   440     removed (interfaces are now regular Isabelle tools).
   441 
   442 Within scripts and make files, the Isabelle environment variables
   443 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   444 respectively.  (The latter are still available as legacy feature.)
   445 
   446 The old isabelle-interface wrapper could react in confusing ways if
   447 the interface was uninstalled or changed otherwise.  Individual
   448 interface tool configuration is now more explicit, see also the
   449 Isabelle system manual.  In particular, Proof General is now available
   450 via "isabelle emacs".
   451 
   452 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   453 purge installed copies of Isabelle executables and re-run "isabelle
   454 install -p ...", or use symlinks.
   455 
   456 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   457 old ~/isabelle, which was slightly non-standard and apt to cause
   458 surprises on case-insensitive file-systems (such as Mac OS).
   459 
   460 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   461 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   462 care is required when using older releases of Isabelle.  Note that
   463 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   464 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   465 
   466 * Proofs of fully specified statements are run in parallel on
   467 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   468 a regular 4-core machine, if the initial heap space is made reasonably
   469 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   470 
   471 * The main reference manuals ("isar-ref", "implementation", and
   472 "system") have been updated and extended.  Formally checked references
   473 as hyperlinks are now available uniformly.
   474 
   475 
   476 *** Pure ***
   477 
   478 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   479 respects.  The most important changes are listed below.  See the
   480 Tutorial on Locales ("locales" manual) for details.
   481 
   482 - In locale expressions, instantiation replaces renaming.  Parameters
   483 must be declared in a for clause.  To aid compatibility with previous
   484 parameter inheritance, in locale declarations, parameters that are not
   485 'touched' (instantiation position "_" or omitted) are implicitly added
   486 with their syntax at the beginning of the for clause.
   487 
   488 - Syntax from abbreviations and definitions in locales is available in
   489 locale expressions and context elements.  The latter is particularly
   490 useful in locale declarations.
   491 
   492 - More flexible mechanisms to qualify names generated by locale
   493 expressions.  Qualifiers (prefixes) may be specified in locale
   494 expressions, and can be marked as mandatory (syntax: "name!:") or
   495 optional (syntax "name?:").  The default depends for plain "name:"
   496 depends on the situation where a locale expression is used: in
   497 commands 'locale' and 'sublocale' prefixes are optional, in
   498 'interpretation' and 'interpret' prefixes are mandatory.  The old
   499 implicit qualifiers derived from the parameter names of a locale are
   500 no longer generated.
   501 
   502 - Command "sublocale l < e" replaces "interpretation l < e".  The
   503 instantiation clause in "interpretation" and "interpret" (square
   504 brackets) is no longer available.  Use locale expressions.
   505 
   506 - When converting proof scripts, mandatory qualifiers in
   507 'interpretation' and 'interpret' should be retained by default, even
   508 if this is an INCOMPATIBILITY compared to former behavior.  In the
   509 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   510 in locale expressions range over a single locale instance only.
   511 
   512 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   513 In existing theorem specifications replace the includes element by the
   514 respective context elements of the included locale, omitting those
   515 that are already present in the theorem specification.  Multiple
   516 assume elements of a locale should be replaced by a single one
   517 involving the locale predicate.  In the proof body, declarations (most
   518 notably theorems) may be regained by interpreting the respective
   519 locales in the proof context as required (command "interpret").
   520 
   521 If using "includes" in replacement of a target solely because the
   522 parameter types in the theorem are not as general as in the target,
   523 consider declaring a new locale with additional type constraints on
   524 the parameters (context element "constrains").
   525 
   526 - Discontinued "locale (open)".  INCOMPATIBILITY.
   527 
   528 - Locale interpretation commands no longer attempt to simplify goal.
   529 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   530 methods intro_locales and unfold_locales to clarify.
   531 
   532 - Locale interpretation commands no longer accept interpretation
   533 attributes.  INCOMPATIBILITY.
   534 
   535 * Class declaration: so-called "base sort" must not be given in import
   536 list any longer, but is inferred from the specification.  Particularly
   537 in HOL, write
   538 
   539     class foo = ...
   540 
   541 instead of
   542 
   543     class foo = type + ...
   544 
   545 * Class target: global versions of theorems stemming do not carry a
   546 parameter prefix any longer.  INCOMPATIBILITY.
   547 
   548 * Class 'instance' command no longer accepts attached definitions.
   549 INCOMPATIBILITY, use proper 'instantiation' target instead.
   550 
   551 * Recovered hiding of consts, which was accidentally broken in
   552 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   553 makes c inaccessible; consider using ``hide (open) const c'' instead.
   554 
   555 * Slightly more coherent Pure syntax, with updated documentation in
   556 isar-ref manual.  Removed locales meta_term_syntax and
   557 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   558 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   559 directly in regular applications.
   560 
   561 * There is a new syntactic category "float_const" for signed decimal
   562 fractions (e.g. 123.45 or -123.45).
   563 
   564 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   565 interface with 'setup' command instead.
   566 
   567 * Command 'local_setup' is similar to 'setup', but operates on a local
   568 theory context.
   569 
   570 * The 'axiomatization' command now only works within a global theory
   571 context.  INCOMPATIBILITY.
   572 
   573 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   574 hypotheses.  Sorts required in the course of reasoning need to be
   575 covered by the constraints in the initial statement, completed by the
   576 type instance information of the background theory.  Non-trivial sort
   577 hypotheses, which rarely occur in practice, may be specified via
   578 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   579 
   580   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   581 
   582 The result contains an implicit sort hypotheses as before --
   583 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   584 normalization.
   585 
   586 * Generalized Isar history, with support for linear undo, direct state
   587 addressing etc.
   588 
   589 * Changed defaults for unify configuration options:
   590 
   591   unify_trace_bound = 50 (formerly 25)
   592   unify_search_bound = 60 (formerly 30)
   593 
   594 * Different bookkeeping for code equations (INCOMPATIBILITY):
   595 
   596   a) On theory merge, the last set of code equations for a particular
   597      constant is taken (in accordance with the policy applied by other
   598      parts of the code generator framework).
   599 
   600   b) Code equations stemming from explicit declarations (e.g. code
   601      attribute) gain priority over default code equations stemming
   602      from definition, primrec, fun etc.
   603 
   604 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   605 
   606 * Unified theorem tables for both code generators.  Thus [code
   607 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   608 
   609 * Command 'find_consts' searches for constants based on type and name
   610 patterns, e.g.
   611 
   612     find_consts "_ => bool"
   613 
   614 By default, matching is against subtypes, but it may be restricted to
   615 the whole type.  Searching by name is possible.  Multiple queries are
   616 conjunctive and queries may be negated by prefixing them with a
   617 hyphen:
   618 
   619     find_consts strict: "_ => bool" name: "Int" -"int => int"
   620 
   621 * New 'find_theorems' criterion "solves" matches theorems that
   622 directly solve the current goal (modulo higher-order unification).
   623 
   624 * Auto solve feature for main theorem statements: whenever a new goal
   625 is stated, "find_theorems solves" is called; any theorems that could
   626 solve the lemma directly are listed as part of the goal state.
   627 Cf. associated options in Proof General Isabelle settings menu,
   628 enabled by default, with reasonable timeout for pathological cases of
   629 higher-order unification.
   630 
   631 
   632 *** Document preparation ***
   633 
   634 * Antiquotation @{lemma} now imitates a regular terminal proof,
   635 demanding keyword 'by' and supporting the full method expression
   636 syntax just like the Isar command 'by'.
   637 
   638 
   639 *** HOL ***
   640 
   641 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   642 points Main and Complex_Main remain as before.
   643 
   644 * Logic image HOL-Plain provides a minimal HOL with the most important
   645 tools available (inductive, datatype, primrec, ...).  This facilitates
   646 experimentation and tool development.  Note that user applications
   647 (and library theories) should never refer to anything below theory
   648 Main, as before.
   649 
   650 * Logic image HOL-Main stops at theory Main, and thus facilitates
   651 experimentation due to shorter build times.
   652 
   653 * Logic image HOL-NSA contains theories of nonstandard analysis which
   654 were previously part of former HOL-Complex.  Entry point Hyperreal
   655 remains valid, but theories formerly using Complex_Main should now use
   656 new entry point Hypercomplex.
   657 
   658 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   659 Posix processes.  Avoids potentially expensive forking of the ML
   660 process.  New thread-based implementation also works on non-Unix
   661 platforms (Cygwin).  Provers are no longer hardwired, but defined
   662 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   663 commands are covered in the isar-ref manual.
   664 
   665 * Wrapper scripts for remote SystemOnTPTP service allows to use
   666 sledgehammer without local ATP installation (Vampire etc.). Other
   667 provers may be included via suitable ML wrappers, see also
   668 src/HOL/ATP_Linkup.thy.
   669 
   670 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   671 menu.
   672 
   673 * The metis method no longer fails because the theorem is too trivial
   674 (contains the empty clause).
   675 
   676 * The metis method now fails in the usual manner, rather than raising
   677 an exception, if it determines that it cannot prove the theorem.
   678 
   679 * Method "coherent" implements a prover for coherent logic (see also
   680 src/Tools/coherent.ML).
   681 
   682 * Constants "undefined" and "default" replace "arbitrary".  Usually
   683 "undefined" is the right choice to replace "arbitrary", though
   684 logically there is no difference.  INCOMPATIBILITY.
   685 
   686 * Command "value" now integrates different evaluation mechanisms.  The
   687 result of the first successful evaluation mechanism is printed.  In
   688 square brackets a particular named evaluation mechanisms may be
   689 specified (currently, [SML], [code] or [nbe]).  See further
   690 src/HOL/ex/Eval_Examples.thy.
   691 
   692 * Normalization by evaluation now allows non-leftlinear equations.
   693 Declare with attribute [code nbe].
   694 
   695 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   696 as the structured Isar versions "cases" and "induct", cf. the
   697 corresponding "cases" and "induct" attributes.  Mutual induction rules
   698 are now presented as a list of individual projections
   699 (e.g. foo_bar.inducts for types foo and bar); the old format with
   700 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   701 rare situations a different rule is selected --- notably nested tuple
   702 elimination instead of former prod.exhaust: use explicit (case_tac t
   703 rule: prod.exhaust) here.
   704 
   705 * Attributes "cases", "induct", "coinduct" support "del" option.
   706 
   707 * Removed fact "case_split_thm", which duplicates "case_split".
   708 
   709 * The option datatype has been moved to a new theory Option.  Renamed
   710 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   711 
   712 * New predicate "strict_mono" classifies strict functions on partial
   713 orders.  With strict functions on linear orders, reasoning about
   714 (in)equalities is facilitated by theorems "strict_mono_eq",
   715 "strict_mono_less_eq" and "strict_mono_less".
   716 
   717 * Some set operations are now proper qualified constants with
   718 authentic syntax.  INCOMPATIBILITY:
   719 
   720     op Int ~>   Set.Int
   721     op Un ~>    Set.Un
   722     INTER ~>    Set.INTER
   723     UNION ~>    Set.UNION
   724     Inter ~>    Set.Inter
   725     Union ~>    Set.Union
   726     {} ~>       Set.empty
   727     UNIV ~>     Set.UNIV
   728 
   729 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   730 theory Set.
   731 
   732 * Auxiliary class "itself" has disappeared -- classes without any
   733 parameter are treated as expected by the 'class' command.
   734 
   735 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   736 
   737 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   738 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   739 
   740 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   741 method "approximation".  It proves formulas on real values by using
   742 interval arithmetic.  In the formulas are also the transcendental
   743 functions sin, cos, tan, atan, ln, exp and the constant pi are
   744 allowed. For examples see
   745 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   746 
   747 * Theory "Reflection" now resides in HOL/Library.
   748 
   749 * Entry point to Word library now simply named "Word".
   750 INCOMPATIBILITY.
   751 
   752 * Made source layout more coherent with logical distribution
   753 structure:
   754 
   755     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   756     src/HOL/Library/Code_Message.thy ~> src/HOL/
   757     src/HOL/Library/GCD.thy ~> src/HOL/
   758     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   759     src/HOL/Library/Parity.thy ~> src/HOL/
   760     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   761     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   762     src/HOL/Real/Lubs.thy ~> src/HOL/
   763     src/HOL/Real/PReal.thy ~> src/HOL/
   764     src/HOL/Real/Rational.thy ~> src/HOL/
   765     src/HOL/Real/RComplete.thy ~> src/HOL/
   766     src/HOL/Real/RealDef.thy ~> src/HOL/
   767     src/HOL/Real/RealPow.thy ~> src/HOL/
   768     src/HOL/Real/Real.thy ~> src/HOL/
   769     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   770     src/HOL/Complex/Complex.thy ~> src/HOL/
   771     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   772     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   773     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   774     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   775     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   776     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   777     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   778     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   779     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   780     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   781     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   782     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   783     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   784     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   785     src/HOL/Real/Float ~> src/HOL/Library/
   786     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   787     src/HOL/Real/RealVector.thy ~> src/HOL/
   788 
   789     src/HOL/arith_data.ML ~> src/HOL/Tools
   790     src/HOL/hologic.ML ~> src/HOL/Tools
   791     src/HOL/simpdata.ML ~> src/HOL/Tools
   792     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   793     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   794     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   795     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   796     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   797     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   798     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   799 
   800     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   801     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   802     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   803     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   804     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   805     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   806 
   807 * If methods "eval" and "evaluation" encounter a structured proof
   808 state with !!/==>, only the conclusion is evaluated to True (if
   809 possible), avoiding strange error messages.
   810 
   811 * Method "sizechange" automates termination proofs using (a
   812 modification of) the size-change principle.  Requires SAT solver.  See
   813 src/HOL/ex/Termination.thy for examples.
   814 
   815 * Simplifier: simproc for let expressions now unfolds if bound
   816 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   817 
   818 * Method "arith": Linear arithmetic now ignores all inequalities when
   819 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   820 
   821 * New attribute "arith" for facts that should always be used
   822 automatically by arithmetic. It is intended to be used locally in
   823 proofs, e.g.
   824 
   825   assumes [arith]: "x > 0"
   826 
   827 Global usage is discouraged because of possible performance impact.
   828 
   829 * New classes "top" and "bot" with corresponding operations "top" and
   830 "bot" in theory Orderings; instantiation of class "complete_lattice"
   831 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   832 
   833 * Changed definition lemma "less_fun_def" in order to provide an
   834 instance for preorders on functions; use lemma "less_le" instead.
   835 INCOMPATIBILITY.
   836 
   837 * Theory Orderings: class "wellorder" moved here, with explicit
   838 induction rule "less_induct" as assumption.  For instantiation of
   839 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   840 INCOMPATIBILITY.
   841 
   842 * Theory Orderings: added class "preorder" as superclass of "order".
   843 INCOMPATIBILITY: Instantiation proofs for order, linorder
   844 etc. slightly changed.  Some theorems named order_class.* now named
   845 preorder_class.*.
   846 
   847 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   848 "diag" to "Id_on".
   849 
   850 * Theory Finite_Set: added a new fold combinator of type
   851 
   852   ('a => 'b => 'b) => 'b => 'a set => 'b
   853 
   854 Occasionally this is more convenient than the old fold combinator
   855 which is now defined in terms of the new one and renamed to
   856 fold_image.
   857 
   858 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   859 and "ring_simps" have been replaced by "algebra_simps" (which can be
   860 extended with further lemmas!).  At the moment both still exist but
   861 the former will disappear at some point.
   862 
   863 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   864 class recpower.  Type-specific simp rules for various recpower types
   865 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   866 
   867 rat_power_0    -> power_0
   868 rat_power_Suc  -> power_Suc
   869 realpow_0      -> power_0
   870 realpow_Suc    -> power_Suc
   871 complexpow_0   -> power_0
   872 complexpow_Suc -> power_Suc
   873 power_poly_0   -> power_0
   874 power_poly_Suc -> power_Suc
   875 
   876 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   877 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   878 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   879 of lemmas from Divides has been generalized from nat to class
   880 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   881 renames resulting from duplicate elimination:
   882 
   883     dvd_def_mod ~>          dvd_eq_mod_eq_0
   884     zero_dvd_iff ~>         dvd_0_left_iff
   885     dvd_0 ~>                dvd_0_right
   886     DIVISION_BY_ZERO_DIV ~> div_by_0
   887     DIVISION_BY_ZERO_MOD ~> mod_by_0
   888     mult_div ~>             div_mult_self2_is_id
   889     mult_mod ~>             mod_mult_self2_is_0
   890 
   891 * Theory IntDiv: removed many lemmas that are instances of class-based
   892 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   893 rename old lemmas as follows:
   894 
   895 dvd_diff               -> nat_dvd_diff
   896 dvd_zminus_iff         -> dvd_minus_iff
   897 mod_add1_eq            -> mod_add_eq
   898 mod_mult1_eq           -> mod_mult_right_eq
   899 mod_mult1_eq'          -> mod_mult_left_eq
   900 mod_mult_distrib_mod   -> mod_mult_eq
   901 nat_mod_add_left_eq    -> mod_add_left_eq
   902 nat_mod_add_right_eq   -> mod_add_right_eq
   903 nat_mod_div_trivial    -> mod_div_trivial
   904 nat_mod_mod_trivial    -> mod_mod_trivial
   905 zdiv_zadd_self1        -> div_add_self1
   906 zdiv_zadd_self2        -> div_add_self2
   907 zdiv_zmult_self1       -> div_mult_self2_is_id
   908 zdiv_zmult_self2       -> div_mult_self1_is_id
   909 zdvd_triv_left         -> dvd_triv_left
   910 zdvd_triv_right        -> dvd_triv_right
   911 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   912 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   913 zmod_zadd_left_eq      -> mod_add_left_eq
   914 zmod_zadd_right_eq     -> mod_add_right_eq
   915 zmod_zadd_self1        -> mod_add_self1
   916 zmod_zadd_self2        -> mod_add_self2
   917 zmod_zadd1_eq          -> mod_add_eq
   918 zmod_zdiff1_eq         -> mod_diff_eq
   919 zmod_zdvd_zmod         -> mod_mod_cancel
   920 zmod_zmod_cancel       -> mod_mod_cancel
   921 zmod_zmult_self1       -> mod_mult_self2_is_0
   922 zmod_zmult_self2       -> mod_mult_self1_is_0
   923 zmod_1                 -> mod_by_1
   924 zdiv_1                 -> div_by_1
   925 zdvd_abs1              -> abs_dvd_iff
   926 zdvd_abs2              -> dvd_abs_iff
   927 zdvd_refl              -> dvd_refl
   928 zdvd_trans             -> dvd_trans
   929 zdvd_zadd              -> dvd_add
   930 zdvd_zdiff             -> dvd_diff
   931 zdvd_zminus_iff        -> dvd_minus_iff
   932 zdvd_zminus2_iff       -> minus_dvd_iff
   933 zdvd_zmultD            -> dvd_mult_right
   934 zdvd_zmultD2           -> dvd_mult_left
   935 zdvd_zmult_mono        -> mult_dvd_mono
   936 zdvd_0_right           -> dvd_0_right
   937 zdvd_0_left            -> dvd_0_left_iff
   938 zdvd_1_left            -> one_dvd
   939 zminus_dvd_iff         -> minus_dvd_iff
   940 
   941 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   942 
   943 * The real numbers offer decimal input syntax: 12.34 is translated
   944 into 1234/10^2. This translation is not reversed upon output.
   945 
   946 * Theory Library/Polynomial defines an abstract type 'a poly of
   947 univariate polynomials with coefficients of type 'a.  In addition to
   948 the standard ring operations, it also supports div and mod.  Code
   949 generation is also supported, using list-style constructors.
   950 
   951 * Theory Library/Inner_Product defines a class of real_inner for real
   952 inner product spaces, with an overloaded operation inner :: 'a => 'a
   953 => real.  Class real_inner is a subclass of real_normed_vector from
   954 theory RealVector.
   955 
   956 * Theory Library/Product_Vector provides instances for the product
   957 type 'a * 'b of several classes from RealVector and Inner_Product.
   958 Definitions of addition, subtraction, scalar multiplication, norms,
   959 and inner products are included.
   960 
   961 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   962 addition to the field operations, numerals and case syntax are also
   963 supported.
   964 
   965 * Theory Library/Diagonalize provides constructive version of Cantor's
   966 first diagonalization argument.
   967 
   968 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   969 zlcm (for int); carried together from various gcd/lcm developements in
   970 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   971 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   972 may recover tupled syntax as follows:
   973 
   974     hide (open) const gcd
   975     abbreviation gcd where
   976       "gcd == (%(a, b). GCD.gcd a b)"
   977     notation (output)
   978       GCD.gcd ("gcd '(_, _')")
   979 
   980 The same works for lcm, zgcd, zlcm.
   981 
   982 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   983 instantiations for algebraic structures.  Removed some duplicate
   984 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   985 
   986 * ML antiquotation @{code} takes a constant as argument and generates
   987 corresponding code in background and inserts name of the corresponding
   988 resulting ML value/function/datatype constructor binding in place.
   989 All occurrences of @{code} with a single ML block are generated
   990 simultaneously.  Provides a generic and safe interface for
   991 instrumentalizing code generation.  See
   992 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
   993 In future you ought to refrain from ad-hoc compiling generated SML
   994 code on the ML toplevel.  Note that (for technical reasons) @{code}
   995 cannot refer to constants for which user-defined serializations are
   996 set.  Refer to the corresponding ML counterpart directly in that
   997 cases.
   998 
   999 * Command 'rep_datatype': instead of theorem names the command now
  1000 takes a list of terms denoting the constructors of the type to be
  1001 represented as datatype.  The characteristic theorems have to be
  1002 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1003 have disappeared in favour of existing ones:
  1004 
  1005     unit_induct                 ~> unit.induct
  1006     prod_induct                 ~> prod.induct
  1007     sum_induct                  ~> sum.induct
  1008     Suc_Suc_eq                  ~> nat.inject
  1009     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1010 
  1011 
  1012 *** HOL-Algebra ***
  1013 
  1014 * New locales for orders and lattices where the equivalence relation
  1015 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1016 locales use a record structure with field eq for the equivalence.
  1017 
  1018 * New theory of factorial domains.
  1019 
  1020 * Units_l_inv and Units_r_inv are now simp rules by default.
  1021 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1022 and/or r_inv will now also require deletion of these lemmas.
  1023 
  1024 * Renamed the following theorems, INCOMPATIBILITY:
  1025 
  1026 UpperD ~> Upper_memD
  1027 LowerD ~> Lower_memD
  1028 least_carrier ~> least_closed
  1029 greatest_carrier ~> greatest_closed
  1030 greatest_Lower_above ~> greatest_Lower_below
  1031 one_zero ~> carrier_one_zero
  1032 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1033 
  1034 
  1035 *** HOL-Nominal ***
  1036 
  1037 * Nominal datatypes can now contain type-variables.
  1038 
  1039 * Commands 'nominal_inductive' and 'equivariance' work with local
  1040 theory targets.
  1041 
  1042 * Nominal primrec can now works with local theory targets and its
  1043 specification syntax now conforms to the general format as seen in
  1044 'inductive' etc.
  1045 
  1046 * Method "perm_simp" honours the standard simplifier attributes
  1047 (no_asm), (no_asm_use) etc.
  1048 
  1049 * The new predicate #* is defined like freshness, except that on the
  1050 left hand side can be a set or list of atoms.
  1051 
  1052 * Experimental command 'nominal_inductive2' derives strong induction
  1053 principles for inductive definitions.  In contrast to
  1054 'nominal_inductive', which can only deal with a fixed number of
  1055 binders, it can deal with arbitrary expressions standing for sets of
  1056 atoms to be avoided.  The only inductive definition we have at the
  1057 moment that needs this generalisation is the typing rule for Lets in
  1058 the algorithm W:
  1059 
  1060  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1061  -----------------------------------------------------------------
  1062          Gamma |- Let x be t1 in t2 : T2
  1063 
  1064 In this rule one wants to avoid all the binders that are introduced by
  1065 "close Gamma T1".  We are looking for other examples where this
  1066 feature might be useful.  Please let us know.
  1067 
  1068 
  1069 *** HOLCF ***
  1070 
  1071 * Reimplemented the simplification procedure for proving continuity
  1072 subgoals.  The new simproc is extensible; users can declare additional
  1073 continuity introduction rules with the attribute [cont2cont].
  1074 
  1075 * The continuity simproc now uses a different introduction rule for
  1076 solving continuity subgoals on terms with lambda abstractions.  In
  1077 some rare cases the new simproc may fail to solve subgoals that the
  1078 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1079 Potential INCOMPATIBILITY.
  1080 
  1081 * Command 'fixrec': specification syntax now conforms to the general
  1082 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1083 examples.  INCOMPATIBILITY.
  1084 
  1085 
  1086 *** ZF ***
  1087 
  1088 * Proof of Zorn's Lemma for partial orders.
  1089 
  1090 
  1091 *** ML ***
  1092 
  1093 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1094 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1095 depends on multithreading, so timouts will not work before Poly/ML
  1096 5.2.1!
  1097 
  1098 * High-level support for concurrent ML programming, see
  1099 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1100 particularly convenient to organize independent functional
  1101 computations.  The concept of "synchronized variables" provides a
  1102 higher-order interface for components with shared state, avoiding the
  1103 delicate details of mutexes and condition variables.  (Requires
  1104 Poly/ML 5.2.1 or later.)
  1105 
  1106 * ML bindings produced via Isar commands are stored within the Isar
  1107 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1108 become thread-safe and work with undo as expected (concerning
  1109 top-level bindings, not side-effects on global references).
  1110 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1111 compiler at runtime; really global bindings need to be given outside a
  1112 theory.  (Requires Poly/ML 5.2 or later.)
  1113 
  1114 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1115 context.  Top-level ML bindings are stored within the proof context in
  1116 a purely sequential fashion, disregarding the nested proof structure.
  1117 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1118 proof.  (Requires Poly/ML 5.2 or later.)
  1119 
  1120 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1121 and Method.setup, as well as Isar commands 'attribute_setup' and
  1122 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1123 existing code accordingly, or use plain 'setup' together with old
  1124 Method.add_method.
  1125 
  1126 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1127 to 'a -> thm, while results are always tagged with an authentic oracle
  1128 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1129 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1130 accordingly.  Note that extra performance may be gained by producing
  1131 the cterm carefully, avoiding slow Thm.cterm_of.
  1132 
  1133 * Simplified interface for defining document antiquotations via
  1134 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1135 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1136 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1137 examples.
  1138 
  1139 * More systematic treatment of long names, abstract name bindings, and
  1140 name space operations.  Basic operations on qualified names have been
  1141 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1142 Long_Name.append.  Old type bstring has been mostly replaced by
  1143 abstract type binding (see structure Binding), which supports precise
  1144 qualification by packages and local theory targets, as well as proper
  1145 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1146 bstring values into Binding.name, or better pass through abstract
  1147 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1148 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1149 
  1150 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1151 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1152 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1153 
  1154 * Disposed old type and term read functions (Sign.read_def_typ,
  1155 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1156 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1157 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1158 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1159 resort for legacy applications.
  1160 
  1161 * Disposed old declarations, tactics, tactic combinators that refer to
  1162 the simpset or claset of an implicit theory (such as Addsimps,
  1163 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1164 embedded ML text, or local_simpset_of with a proper context passed as
  1165 explicit runtime argument.
  1166 
  1167 * Rules and tactics that read instantiations (read_instantiate,
  1168 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1169 context, which is required for parsing and type-checking.  Moreover,
  1170 the variables are specified as plain indexnames, not string encodings
  1171 thereof.  INCOMPATIBILITY.
  1172 
  1173 * Generic Toplevel.add_hook interface allows to analyze the result of
  1174 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1175 for theorem dependency output of transactions resulting in a new
  1176 theory state.
  1177 
  1178 * ML antiquotations: block-structured compilation context indicated by
  1179 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1180 
  1181   @{binding name}                         - basic name binding
  1182   @{let ?pat = term}                      - term abbreviation (HO matching)
  1183   @{note name = fact}                     - fact abbreviation
  1184   @{thm fact}                             - singleton fact (with attributes)
  1185   @{thms fact}                            - general fact (with attributes)
  1186   @{lemma prop by method}                 - singleton goal
  1187   @{lemma prop by meth1 meth2}            - singleton goal
  1188   @{lemma prop1 ... propN by method}      - general goal
  1189   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1190   @{lemma (open) ...}                     - open derivation
  1191 
  1192 
  1193 *** System ***
  1194 
  1195 * The Isabelle "emacs" tool provides a specific interface to invoke
  1196 Proof General / Emacs, with more explicit failure if that is not
  1197 installed (the old isabelle-interface script silently falls back on
  1198 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1199 installation location of the Proof General distribution.
  1200 
  1201 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1202 the Isabelle process into a JVM/Scala application.  See
  1203 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1204 process wrapper has been discontinued.)
  1205 
  1206 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1207 
  1208 * Various status messages (with exact source position information) are
  1209 emitted, if proper markup print mode is enabled.  This allows
  1210 user-interface components to provide detailed feedback on internal
  1211 prover operations.
  1212 
  1213 
  1214 
  1215 New in Isabelle2008 (June 2008)
  1216 -------------------------------
  1217 
  1218 *** General ***
  1219 
  1220 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1221 and updated, with formally checked references as hyperlinks.
  1222 
  1223 * Theory loader: use_thy (and similar operations) no longer set the
  1224 implicit ML context, which was occasionally hard to predict and in
  1225 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1226 provides a proper context already.
  1227 
  1228 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1229 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1230 'use' within a theory file will do the job.
  1231 
  1232 * Name space merge now observes canonical order, i.e. the second space
  1233 is inserted into the first one, while existing entries in the first
  1234 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1235 swap theory imports.
  1236 
  1237 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1238 INCOMPATIBILITY in identifier syntax etc.
  1239 
  1240 * Outer syntax: string tokens no longer admit escaped white space,
  1241 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1242 white space without escapes.
  1243 
  1244 * Outer syntax: string tokens may contain arbitrary character codes
  1245 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1246 "foo_bar".
  1247 
  1248 
  1249 *** Pure ***
  1250 
  1251 * Context-dependent token translations.  Default setup reverts locally
  1252 fixed variables, and adds hilite markup for undeclared frees.
  1253 
  1254 * Unused theorems can be found using the new command 'unused_thms'.
  1255 There are three ways of invoking it:
  1256 
  1257 (1) unused_thms
  1258      Only finds unused theorems in the current theory.
  1259 
  1260 (2) unused_thms thy_1 ... thy_n -
  1261      Finds unused theorems in the current theory and all of its ancestors,
  1262      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1263 
  1264 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1265      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1266      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1267      their ancestors.
  1268 
  1269 In order to increase the readability of the list produced by
  1270 unused_thms, theorems that have been created by a particular instance
  1271 of a theory command such as 'inductive' or 'function' are considered
  1272 to belong to the same "group", meaning that if at least one theorem in
  1273 this group is used, the other theorems in the same group are no longer
  1274 reported as unused.  Moreover, if all theorems in the group are
  1275 unused, only one theorem in the group is displayed.
  1276 
  1277 Note that proof objects have to be switched on in order for
  1278 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1279 usually the case when using Proof General with the default settings).
  1280 
  1281 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1282 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1283 duplicate fact bindings, or even accidental fact duplications.  Note
  1284 that tools may maintain dynamically scoped facts systematically, using
  1285 PureThy.add_thms_dynamic.
  1286 
  1287 * Command 'hide' now allows to hide from "fact" name space as well.
  1288 
  1289 * Eliminated destructive theorem database, simpset, claset, and
  1290 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1291 update of theories within ML code.
  1292 
  1293 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1294 INCOMPATIBILITY, object-logics depending on former Pure require
  1295 additional setup PureThy.old_appl_syntax_setup; object-logics
  1296 depending on former CPure need to refer to Pure.
  1297 
  1298 * Commands 'use' and 'ML' are now purely functional, operating on
  1299 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1300 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1301 INCOMPATIBILITY.
  1302 
  1303 * Command 'setup': discontinued implicit version with ML reference.
  1304 
  1305 * Instantiation target allows for simultaneous specification of class
  1306 instance operations together with an instantiation proof.
  1307 Type-checking phase allows to refer to class operations uniformly.
  1308 See src/HOL/Complex/Complex.thy for an Isar example and
  1309 src/HOL/Library/Eval.thy for an ML example.
  1310 
  1311 * Indexing of literal facts: be more serious about including only
  1312 facts from the visible specification/proof context, but not the
  1313 background context (locale etc.).  Affects `prop` notation and method
  1314 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1315 situations.
  1316 
  1317 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1318 "(open)" option, which used to expose internal bound variables to the
  1319 proof text.
  1320 
  1321 * Isar statements: removed obsolete case "rule_context".
  1322 INCOMPATIBILITY, better use explicit fixes/assumes.
  1323 
  1324 * Locale proofs: default proof step now includes 'unfold_locales';
  1325 hence 'proof' without argument may be used to unfold locale
  1326 predicates.
  1327 
  1328 
  1329 *** Document preparation ***
  1330 
  1331 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1332 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1333 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1334 spot); renamed link color from "darkblue" to "linkcolor" (default
  1335 value unchanged, can be redefined via \definecolor); no longer sets
  1336 "a4paper" option (unnecessary or even intrusive).
  1337 
  1338 * Antiquotation @{lemma A method} proves proposition A by the given
  1339 method (either a method name or a method name plus (optional) method
  1340 arguments in parentheses) and prints A just like @{prop A}.
  1341 
  1342 
  1343 *** HOL ***
  1344 
  1345 * New primrec package.  Specification syntax conforms in style to
  1346 definition/function/....  No separate induction rule is provided.  The
  1347 "primrec" command distinguishes old-style and new-style specifications
  1348 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1349 When adjusting theories, beware: constants stemming from new-style
  1350 primrec specifications have authentic syntax.
  1351 
  1352 * Metis prover is now an order of magnitude faster, and also works
  1353 with multithreading.
  1354 
  1355 * Metis: the maximum number of clauses that can be produced from a
  1356 theorem is now given by the attribute max_clauses.  Theorems that
  1357 exceed this number are ignored, with a warning printed.
  1358 
  1359 * Sledgehammer no longer produces structured proofs by default. To
  1360 enable, declare [[sledgehammer_full = true]].  Attributes
  1361 reconstruction_modulus, reconstruction_sorts renamed
  1362 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1363 
  1364 * Method "induct_scheme" derives user-specified induction rules
  1365 from well-founded induction and completeness of patterns. This factors
  1366 out some operations that are done internally by the function package
  1367 and makes them available separately.  See
  1368 src/HOL/ex/Induction_Scheme.thy for examples.
  1369 
  1370 * More flexible generation of measure functions for termination
  1371 proofs: Measure functions can be declared by proving a rule of the
  1372 form "is_measure f" and giving it the [measure_function] attribute.
  1373 The "is_measure" predicate is logically meaningless (always true), and
  1374 just guides the heuristic.  To find suitable measure functions, the
  1375 termination prover sets up the goal "is_measure ?f" of the appropriate
  1376 type and generates all solutions by prolog-style backwards proof using
  1377 the declared rules.
  1378 
  1379 This setup also deals with rules like 
  1380 
  1381   "is_measure f ==> is_measure (list_size f)"
  1382 
  1383 which accommodates nested datatypes that recurse through lists.
  1384 Similar rules are predeclared for products and option types.
  1385 
  1386 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1387 
  1388   INCOMPATIBILITIES:
  1389 
  1390   - Definitions of overloaded constants on sets have to be replaced by
  1391     definitions on => and bool.
  1392 
  1393   - Some definitions of overloaded operators on sets can now be proved
  1394     using the definitions of the operators on => and bool.  Therefore,
  1395     the following theorems have been renamed:
  1396 
  1397       subset_def   -> subset_eq
  1398       psubset_def  -> psubset_eq
  1399       set_diff_def -> set_diff_eq
  1400       Compl_def    -> Compl_eq
  1401       Sup_set_def  -> Sup_set_eq
  1402       Inf_set_def  -> Inf_set_eq
  1403       sup_set_def  -> sup_set_eq
  1404       inf_set_def  -> inf_set_eq
  1405 
  1406   - Due to the incompleteness of the HO unification algorithm, some
  1407     rules such as subst may require manual instantiation, if some of
  1408     the unknowns in the rule is a set.
  1409 
  1410   - Higher order unification and forward proofs:
  1411     The proof pattern
  1412 
  1413       have "P (S::'a set)" <...>
  1414       then have "EX S. P S" ..
  1415 
  1416     no longer works (due to the incompleteness of the HO unification
  1417     algorithm) and must be replaced by the pattern
  1418 
  1419       have "EX S. P S"
  1420       proof
  1421         show "P S" <...>
  1422       qed
  1423 
  1424   - Calculational reasoning with subst (or similar rules):
  1425     The proof pattern
  1426 
  1427       have "P (S::'a set)" <...>
  1428       also have "S = T" <...>
  1429       finally have "P T" .
  1430 
  1431     no longer works (for similar reasons as the previous example) and
  1432     must be replaced by something like
  1433 
  1434       have "P (S::'a set)" <...>
  1435       moreover have "S = T" <...>
  1436       ultimately have "P T" by simp
  1437 
  1438   - Tactics or packages written in ML code:
  1439     Code performing pattern matching on types via
  1440 
  1441       Type ("set", [T]) => ...
  1442 
  1443     must be rewritten. Moreover, functions like strip_type or
  1444     binder_types no longer return the right value when applied to a
  1445     type of the form
  1446 
  1447       T1 => ... => Tn => U => bool
  1448 
  1449     rather than
  1450 
  1451       T1 => ... => Tn => U set
  1452 
  1453 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1454 Wellfounded_Relations to theory Wellfounded.
  1455 
  1456 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1457 
  1458 * Class finite no longer treats UNIV as class parameter.  Use class
  1459 enum from theory Library/Enum instead to achieve a similar effect.
  1460 INCOMPATIBILITY.
  1461 
  1462 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1463 and "Cons".  INCOMPATIBILITY.
  1464 
  1465 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1466 Potential INCOMPATIBILITY.
  1467 
  1468 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1469 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1470 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1471 
  1472 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1473 the same name in theory Orderings:
  1474 
  1475   less_trans
  1476   less_linear
  1477   le_imp_less_or_eq
  1478   le_less_trans
  1479   less_le_trans
  1480   less_not_sym
  1481   less_asym
  1482 
  1483 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1484 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1485 and different variable names.
  1486 
  1487 * Library/Option_ord.thy: Canonical order on option type.
  1488 
  1489 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1490 finite maps.
  1491 
  1492 * Library/Countable.thy: Type class for countable types.
  1493 
  1494 * Theory Int: The representation of numerals has changed.  The infix
  1495 operator BIT and the bit datatype with constructors B0 and B1 have
  1496 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1497 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1498 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1499 accordingly.
  1500 
  1501 * Theory Nat: definition of <= and < on natural numbers no longer
  1502 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1503 le_def and less_def have disappeared.  Consider lemmas not_less
  1504 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1505 
  1506 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1507 (whose purpose mainly is for various fold_set functionals) have been
  1508 abandoned in favor of the existing algebraic classes
  1509 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1510 lower_semilattice (resp. upper_semilattice) and linorder.
  1511 INCOMPATIBILITY.
  1512 
  1513 * Theory Transitive_Closure: induct and cases rules now declare proper
  1514 case_names ("base" and "step").  INCOMPATIBILITY.
  1515 
  1516 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1517 lattices.  The form set-specific version is available as
  1518 Inductive.lfp_ordinal_induct_set.
  1519 
  1520 * Renamed theorems "power.simps" to "power_int.simps".
  1521 INCOMPATIBILITY.
  1522 
  1523 * Class semiring_div provides basic abstract properties of semirings
  1524 with division and modulo operations.  Subsumes former class dvd_mod.
  1525 
  1526 * Merged theories IntDef, Numeral and IntArith into unified theory
  1527 Int.  INCOMPATIBILITY.
  1528 
  1529 * Theory Library/Code_Index: type "index" now represents natural
  1530 numbers rather than integers.  INCOMPATIBILITY.
  1531 
  1532 * New class "uminus" with operation "uminus" (split of from class
  1533 "minus" which now only has operation "minus", binary).
  1534 INCOMPATIBILITY.
  1535 
  1536 * Constants "card", "internal_split", "option_map" now with authentic
  1537 syntax.  INCOMPATIBILITY.
  1538 
  1539 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1540 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1541 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1542 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1543 Sup_set_def, le_def, less_def, option_map_def now with object
  1544 equality.  INCOMPATIBILITY.
  1545 
  1546 * Records. Removed K_record, and replaced it by pure lambda term
  1547 %x. c. The simplifier setup is now more robust against eta expansion.
  1548 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1549 
  1550 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1551 
  1552 * Library/ListVector: new theory of arithmetic vector operations.
  1553 
  1554 * Library/Order_Relation: new theory of various orderings as sets of
  1555 pairs.  Defines preorders, partial orders, linear orders and
  1556 well-orders on sets and on types.
  1557 
  1558 
  1559 *** ZF ***
  1560 
  1561 * Renamed some theories to allow to loading both ZF and HOL in the
  1562 same session:
  1563 
  1564   Datatype  -> Datatype_ZF
  1565   Inductive -> Inductive_ZF
  1566   Int       -> Int_ZF
  1567   IntDiv    -> IntDiv_ZF
  1568   Nat       -> Nat_ZF
  1569   List      -> List_ZF
  1570   Main      -> Main_ZF
  1571 
  1572 INCOMPATIBILITY: ZF theories that import individual theories below
  1573 Main might need to be adapted.  Regular theory Main is still
  1574 available, as trivial extension of Main_ZF.
  1575 
  1576 
  1577 *** ML ***
  1578 
  1579 * ML within Isar: antiquotation @{const name} or @{const
  1580 name(typargs)} produces statically-checked Const term.
  1581 
  1582 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1583 (of the same name).  Removed obsolete print command.
  1584 
  1585 * Removed obsolete "use_legacy_bindings" function.
  1586 
  1587 * The ``print mode'' is now a thread-local value derived from a global
  1588 template (the former print_mode reference), thus access becomes
  1589 non-critical.  The global print_mode reference is for session
  1590 management only; user-code should use print_mode_value,
  1591 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1592 
  1593 * Functions system/system_out provide a robust way to invoke external
  1594 shell commands, with propagation of interrupts (requires Poly/ML
  1595 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1596 
  1597 
  1598 *** System ***
  1599 
  1600 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1601 in accordance with Proof General 3.7, which prefers GNU emacs.
  1602 
  1603 * isatool tty runs Isabelle process with plain tty interaction;
  1604 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1605 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1606 
  1607 * isatool browser now works with Cygwin as well, using general
  1608 "javapath" function defined in Isabelle process environment.
  1609 
  1610 * YXML notation provides a simple and efficient alternative to
  1611 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1612 isatool yxml as described in the Isabelle system manual.
  1613 
  1614 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1615 provides general wrapper for managing an Isabelle process in a robust
  1616 fashion, with ``cooked'' output from stdin/stderr.
  1617 
  1618 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1619 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1620 
  1621 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1622 way of changing the user's settings is via
  1623 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1624 script.
  1625 
  1626 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1627 cores of the underlying machine, which is a good starting point for
  1628 optimal performance tuning.  The corresponding usedir option -M allows
  1629 "max" as an alias for "0".  WARNING: does not work on certain versions
  1630 of Mac OS (with Poly/ML 5.1).
  1631 
  1632 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1633 adverse effect of Isabelle flooding interactive front-ends (notably
  1634 ProofGeneral / XEmacs).
  1635 
  1636 
  1637 
  1638 New in Isabelle2007 (November 2007)
  1639 -----------------------------------
  1640 
  1641 *** General ***
  1642 
  1643 * More uniform information about legacy features, notably a
  1644 warning/error of "Legacy feature: ...", depending on the state of the
  1645 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1646 legacy features will disappear eventually.
  1647 
  1648 * Theory syntax: the header format ``theory A = B + C:'' has been
  1649 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1650 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1651 
  1652 * Theory syntax: the old non-Isar theory file format has been
  1653 discontinued altogether.  Note that ML proof scripts may still be used
  1654 with Isar theories; migration is usually quite simple with the ML
  1655 function use_legacy_bindings.  INCOMPATIBILITY.
  1656 
  1657 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1658 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1659 quotes.
  1660 
  1661 * Theory loader: be more serious about observing the static theory
  1662 header specifications (including optional directories), but not the
  1663 accidental file locations of previously successful loads.  The strict
  1664 update policy of former update_thy is now already performed by
  1665 use_thy, so the former has been removed; use_thys updates several
  1666 theories simultaneously, just as 'imports' within a theory header
  1667 specification, but without merging the results.  Potential
  1668 INCOMPATIBILITY: may need to refine theory headers and commands
  1669 ROOT.ML which depend on load order.
  1670 
  1671 * Theory loader: optional support for content-based file
  1672 identification, instead of the traditional scheme of full physical
  1673 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1674 (cf. the system manual).  The new scheme allows to work with
  1675 non-finished theories in persistent session images, such that source
  1676 files may be moved later on without requiring reloads.
  1677 
  1678 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1679 file (with the same base name as the theory) are considered a legacy
  1680 feature, which will disappear eventually. Even now, the theory loader
  1681 no longer maintains dependencies on such files.
  1682 
  1683 * Syntax: the scope for resolving ambiguities via type-inference is
  1684 now limited to individual terms, instead of whole simultaneous
  1685 specifications as before. This greatly reduces the complexity of the
  1686 syntax module and improves flexibility by separating parsing and
  1687 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1688 'fixes' etc.) are required in rare situations.
  1689 
  1690 * Syntax: constants introduced by new-style packages ('definition',
  1691 'abbreviation' etc.) are passed through the syntax module in
  1692 ``authentic mode''. This means that associated mixfix annotations
  1693 really stick to such constants, independently of potential name space
  1694 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1695 trees are represented slightly differently, may need to adapt syntax
  1696 translations accordingly. Use CONST marker in 'translations' and
  1697 @{const_syntax} antiquotation in 'parse_translation' etc.
  1698 
  1699 * Legacy goal package: reduced interface to the bare minimum required
  1700 to keep existing proof scripts running.  Most other user-level
  1701 functions are now part of the OldGoals structure, which is *not* open
  1702 by default (consider isatool expandshort before open OldGoals).
  1703 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1704 these tend to cause confusion about the actual goal (!) context being
  1705 used here, which is not necessarily the same as the_context().
  1706 
  1707 * Command 'find_theorems': supports "*" wild-card in "name:"
  1708 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1709 support a specific search form (see ProofGeneral/CHANGES).
  1710 
  1711 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1712 by default, which means that "prems" (and also "fixed variables") are
  1713 suppressed from proof state output.  Note that the ProofGeneral
  1714 settings mechanism allows to change and save options persistently, but
  1715 older versions of Isabelle will fail to start up if a negative prems
  1716 limit is imposed.
  1717 
  1718 * Local theory targets may be specified by non-nested blocks of
  1719 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1720 contain definitions, theorems etc., including any derived mechanism
  1721 that has been implemented on top of these primitives.  This concept
  1722 generalizes the existing ``theorem (in ...)'' towards more versatility
  1723 and scalability.
  1724 
  1725 * Proof General interface: proper undo of final 'end' command;
  1726 discontinued Isabelle/classic mode (ML proof scripts).
  1727 
  1728 
  1729 *** Document preparation ***
  1730 
  1731 * Added antiquotation @{theory name} which prints the given name,
  1732 after checking that it refers to a valid ancestor theory in the
  1733 current context.
  1734 
  1735 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1736 check the given source text as ML type/structure, printing verbatim.
  1737 
  1738 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1739 "c args == rhs" given in the current context.  (Any number of
  1740 arguments may be given on the LHS.)
  1741 
  1742 
  1743 *** Pure ***
  1744 
  1745 * The 'class' package offers a combination of axclass and locale to
  1746 achieve Haskell-like type classes in Isabelle.  Definitions and
  1747 theorems within a class context produce both relative results (with
  1748 implicit parameters according to the locale context), and polymorphic
  1749 constants with qualified polymorphism (according to the class
  1750 context).  Within the body context of a 'class' target, a separate
  1751 syntax layer ("user space type system") takes care of converting
  1752 between global polymorphic consts and internal locale representation.
  1753 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1754 "isatool doc classes" provides a tutorial.
  1755 
  1756 * Generic code generator framework allows to generate executable
  1757 code for ML and Haskell (including Isabelle classes).  A short usage
  1758 sketch:
  1759 
  1760     internal compilation:
  1761         export_code <list of constants (term syntax)> in SML
  1762     writing SML code to a file:
  1763         export_code <list of constants (term syntax)> in SML <filename>
  1764     writing OCaml code to a file:
  1765         export_code <list of constants (term syntax)> in OCaml <filename>
  1766     writing Haskell code to a bunch of files:
  1767         export_code <list of constants (term syntax)> in Haskell <filename>
  1768 
  1769     evaluating closed propositions to True/False using code generation:
  1770         method ``eval''
  1771 
  1772 Reasonable default setup of framework in HOL.
  1773 
  1774 Theorem attributs for selecting and transforming function equations theorems:
  1775 
  1776     [code fun]:        select a theorem as function equation for a specific constant
  1777     [code fun del]:    deselect a theorem as function equation for a specific constant
  1778     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1779     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1780 
  1781 User-defined serializations (target in {SML, OCaml, Haskell}):
  1782 
  1783     code_const <and-list of constants (term syntax)>
  1784       {(target) <and-list of const target syntax>}+
  1785 
  1786     code_type <and-list of type constructors>
  1787       {(target) <and-list of type target syntax>}+
  1788 
  1789     code_instance <and-list of instances>
  1790       {(target)}+
  1791         where instance ::= <type constructor> :: <class>
  1792 
  1793     code_class <and_list of classes>
  1794       {(target) <and-list of class target syntax>}+
  1795         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1796 
  1797 code_instance and code_class only are effective to target Haskell.
  1798 
  1799 For example usage see src/HOL/ex/Codegenerator.thy and
  1800 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1801 generation from Isabelle/HOL theories is available via "isatool doc
  1802 codegen".
  1803 
  1804 * Code generator: consts in 'consts_code' Isar commands are now
  1805 referred to by usual term syntax (including optional type
  1806 annotations).
  1807 
  1808 * Command 'no_translations' removes translation rules from theory
  1809 syntax.
  1810 
  1811 * Overloaded definitions are now actually checked for acyclic
  1812 dependencies.  The overloading scheme is slightly more general than
  1813 that of Haskell98, although Isabelle does not demand an exact
  1814 correspondence to type class and instance declarations.
  1815 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1816 exotic versions of overloading -- at the discretion of the user!
  1817 
  1818 Polymorphic constants are represented via type arguments, i.e. the
  1819 instantiation that matches an instance against the most general
  1820 declaration given in the signature.  For example, with the declaration
  1821 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1822 as c(nat).  Overloading is essentially simultaneous structural
  1823 recursion over such type arguments.  Incomplete specification patterns
  1824 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1825 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1826 Command 'print_theory' outputs the normalized system of recursive
  1827 equations, see section "definitions".
  1828 
  1829 * Configuration options are maintained within the theory or proof
  1830 context (with name and type bool/int/string), providing a very simple
  1831 interface to a poor-man's version of general context data.  Tools may
  1832 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1833 these values using Config.get etc.  Users may change options via an
  1834 associated attribute of the same name.  This form of context
  1835 declaration works particularly well with commands 'declare' or
  1836 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1837 very easy to avoid global references, which would not observe Isar
  1838 toplevel undo/redo and fail to work with multithreading.
  1839 
  1840 Various global ML references of Pure and HOL have been turned into
  1841 configuration options:
  1842 
  1843   Unify.search_bound		unify_search_bound
  1844   Unify.trace_bound		unify_trace_bound
  1845   Unify.trace_simp		unify_trace_simp
  1846   Unify.trace_types		unify_trace_types
  1847   Simplifier.simp_depth_limit	simp_depth_limit
  1848   Blast.depth_limit		blast_depth_limit
  1849   DatatypeProp.dtK		datatype_distinctness_limit
  1850   fast_arith_neq_limit  	fast_arith_neq_limit
  1851   fast_arith_split_limit	fast_arith_split_limit
  1852 
  1853 * Named collections of theorems may be easily installed as context
  1854 data using the functor NamedThmsFun (see also
  1855 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1856 attributes; there is also a toplevel print command.  This facility is
  1857 just a common case of general context data, which is the preferred way
  1858 for anything more complex than just a list of facts in canonical
  1859 order.
  1860 
  1861 * Isar: command 'declaration' augments a local theory by generic
  1862 declaration functions written in ML.  This enables arbitrary content
  1863 being added to the context, depending on a morphism that tells the
  1864 difference of the original declaration context wrt. the application
  1865 context encountered later on.
  1866 
  1867 * Isar: proper interfaces for simplification procedures.  Command
  1868 'simproc_setup' declares named simprocs (with match patterns, and body
  1869 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1870 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1871 
  1872 * Isar: an extra pair of brackets around attribute declarations
  1873 abbreviates a theorem reference involving an internal dummy fact,
  1874 which will be ignored later --- only the effect of the attribute on
  1875 the background context will persist.  This form of in-place
  1876 declarations is particularly useful with commands like 'declare' and
  1877 'using', for example ``have A using [[simproc a]] by simp''.
  1878 
  1879 * Isar: method "assumption" (and implicit closing of subproofs) now
  1880 takes simple non-atomic goal assumptions into account: after applying
  1881 an assumption as a rule the resulting subgoals are solved by atomic
  1882 assumption steps.  This is particularly useful to finish 'obtain'
  1883 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1884 without referring to the original premise "!!x. P x ==> thesis" in the
  1885 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1886 more permissive.
  1887 
  1888 * Isar: implicit use of prems from the Isar proof context is
  1889 considered a legacy feature.  Common applications like ``have A .''
  1890 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1891 referencing facts explicitly here improves readability and
  1892 maintainability of proof texts.
  1893 
  1894 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1895 the obtained context from the course of reasoning!  For example:
  1896 
  1897   assume "EX x y. A x & B y"   -- "any previous fact"
  1898   then guess x and y by clarify
  1899 
  1900 This technique is potentially adventurous, depending on the facts and
  1901 proof tools being involved here.
  1902 
  1903 * Isar: known facts from the proof context may be specified as literal
  1904 propositions, using ASCII back-quote syntax.  This works wherever
  1905 named facts used to be allowed so far, in proof commands, proof
  1906 methods, attributes etc.  Literal facts are retrieved from the context
  1907 according to unification of type and term parameters.  For example,
  1908 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1909 theorems in the current context, then these are valid literal facts:
  1910 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1911 
  1912 There is also a proof method "fact" which does the same composition
  1913 for explicit goal states, e.g. the following proof texts coincide with
  1914 certain special cases of literal facts:
  1915 
  1916   have "A" by fact                 ==  note `A`
  1917   have "A ==> B" by fact           ==  note `A ==> B`
  1918   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1919   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1920 
  1921 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1922 outer syntax.  Thus symbolic identifiers may be used without
  1923 additional white space in declarations like this: ``assume *: A''.
  1924 
  1925 * Isar: 'print_facts' prints all local facts of the current context,
  1926 both named and unnamed ones.
  1927 
  1928 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1929 
  1930   def x == "t" and y == "u"
  1931 
  1932 * Isar: added command 'unfolding', which is structurally similar to
  1933 'using', but affects both the goal state and facts by unfolding given
  1934 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1935 'unfolded' attribute may be replaced by first-class proof text.
  1936 
  1937 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1938 and command 'unfolding' now all support object-level equalities
  1939 (potentially conditional).  The underlying notion of rewrite rule is
  1940 analogous to the 'rule_format' attribute, but *not* that of the
  1941 Simplifier (which is usually more generous).
  1942 
  1943 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1944 premises of a theorem by n. Useful in conjunction with drule.
  1945 
  1946 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1947 method expression within a sandbox consisting of the first N
  1948 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1949 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1950 simplifies all new goals that emerge from applying rule foo to the
  1951 originally first one.
  1952 
  1953 * Isar: schematic goals are no longer restricted to higher-order
  1954 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1955 expected.
  1956 
  1957 * Isar: the conclusion of a long theorem statement is now either
  1958 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1959 (essentially a disjunction of cases with local parameters and
  1960 assumptions).  The latter allows to express general elimination rules
  1961 adequately; in this notation common elimination rules look like this:
  1962 
  1963   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1964     assumes "EX x. P x"
  1965     obtains x where "P x"
  1966 
  1967   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1968     assumes "A & B"
  1969     obtains A and B
  1970 
  1971   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1972     assumes "A | B"
  1973     obtains
  1974       A
  1975     | B
  1976 
  1977 The subsequent classical rules even refer to the formal "thesis"
  1978 explicitly:
  1979 
  1980   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1981     obtains "~ thesis"
  1982 
  1983   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1984     obtains "thesis ==> something"
  1985 
  1986 The actual proof of an 'obtains' statement is analogous to that of the
  1987 Isar proof element 'obtain', only that there may be several cases.
  1988 Optional case names may be specified in parentheses; these will be
  1989 available both in the present proof and as annotations in the
  1990 resulting rule, for later use with the 'cases' method (cf. attribute
  1991 case_names).
  1992 
  1993 * Isar: the assumptions of a long theorem statement are available as
  1994 "assms" fact in the proof context.  This is more appropriate than the
  1995 (historical) "prems", which refers to all assumptions of the current
  1996 context, including those from the target locale, proof body etc.
  1997 
  1998 * Isar: 'print_statement' prints theorems from the current theory or
  1999 proof context in long statement form, according to the syntax of a
  2000 top-level lemma.
  2001 
  2002 * Isar: 'obtain' takes an optional case name for the local context
  2003 introduction rule (default "that").
  2004 
  2005 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2006 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2007 to occur.
  2008 
  2009 * Pure: syntax "CONST name" produces a fully internalized constant
  2010 according to the current context.  This is particularly useful for
  2011 syntax translations that should refer to internal constant
  2012 representations independently of name spaces.
  2013 
  2014 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2015 instead of "FOO ". This allows multiple binder declarations to coexist
  2016 in the same context.  INCOMPATIBILITY.
  2017 
  2018 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2019 primitive that also works in a locale context (both for constants and
  2020 fixed variables). Type declaration and internal syntactic representation
  2021 of given constants retrieved from the context. Likewise, the
  2022 'no_notation' command allows to remove given syntax annotations from the
  2023 current context.
  2024 
  2025 * Isar/locales: new derived specification elements 'axiomatization',
  2026 'definition', 'abbreviation', which support type-inference, admit
  2027 object-level specifications (equality, equivalence).  See also the
  2028 isar-ref manual.  Examples:
  2029 
  2030   axiomatization
  2031     eq  (infix "===" 50) where
  2032     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2033 
  2034   definition "f x y = x + y + 1"
  2035   definition g where "g x = f x x"
  2036 
  2037   abbreviation
  2038     neq  (infix "=!=" 50) where
  2039     "x =!= y == ~ (x === y)"
  2040 
  2041 These specifications may be also used in a locale context.  Then the
  2042 constants being introduced depend on certain fixed parameters, and the
  2043 constant name is qualified by the locale base name.  An internal
  2044 abbreviation takes care for convenient input and output, making the
  2045 parameters implicit and using the original short name.  See also
  2046 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2047 entities from a monomorphic theory.
  2048 
  2049 Presently, abbreviations are only available 'in' a target locale, but
  2050 not inherited by general import expressions.  Also note that
  2051 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2052 'translations' in common applications.  The "no_abbrevs" print mode
  2053 prevents folding of abbreviations in term output.
  2054 
  2055 Concrete syntax is attached to specified constants in internal form,
  2056 independently of name spaces.  The parse tree representation is
  2057 slightly different -- use 'notation' instead of raw 'syntax', and
  2058 'translations' with explicit "CONST" markup to accommodate this.
  2059 
  2060 * Pure/Isar: unified syntax for new-style specification mechanisms
  2061 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2062 full type inference and dummy patterns ("_").  For example:
  2063 
  2064   definition "K x _ = x"
  2065 
  2066   inductive conj for A B
  2067   where "A ==> B ==> conj A B"
  2068 
  2069 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2070 the current context.  Print mode "no_abbrevs" prevents inversion of
  2071 abbreviations on output.
  2072 
  2073 * Isar/locales: improved parameter handling: use of locales "var" and
  2074 "struct" no longer necessary; - parameter renamings are no longer
  2075 required to be injective.  For example, this allows to define
  2076 endomorphisms as locale endom = homom mult mult h.
  2077 
  2078 * Isar/locales: changed the way locales with predicates are defined.
  2079 Instead of accumulating the specification, the imported expression is
  2080 now an interpretation.  INCOMPATIBILITY: different normal form of
  2081 locale expressions.  In particular, in interpretations of locales with
  2082 predicates, goals repesenting already interpreted fragments are not
  2083 removed automatically.  Use methods `intro_locales' and
  2084 `unfold_locales'; see below.
  2085 
  2086 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2087 provide backward reasoning on locales predicates.  The methods are
  2088 aware of interpretations and discharge corresponding goals.
  2089 `intro_locales' is less aggressive then `unfold_locales' and does not
  2090 unfold predicates to assumptions.
  2091 
  2092 * Isar/locales: the order in which locale fragments are accumulated
  2093 has changed.  This enables to override declarations from fragments due
  2094 to interpretations -- for example, unwanted simp rules.
  2095 
  2096 * Isar/locales: interpretation in theories and proof contexts has been
  2097 extended.  One may now specify (and prove) equations, which are
  2098 unfolded in interpreted theorems.  This is useful for replacing
  2099 defined concepts (constants depending on locale parameters) by
  2100 concepts already existing in the target context.  Example:
  2101 
  2102   interpretation partial_order ["op <= :: [int, int] => bool"]
  2103     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2104 
  2105 Typically, the constant `partial_order.less' is created by a
  2106 definition specification element in the context of locale
  2107 partial_order.
  2108 
  2109 * Method "induct": improved internal context management to support
  2110 local fixes and defines on-the-fly. Thus explicit meta-level
  2111 connectives !!  and ==> are rarely required anymore in inductive goals
  2112 (using object-logic connectives for this purpose has been long
  2113 obsolete anyway). Common proof patterns are explained in
  2114 src/HOL/Induct/Common_Patterns.thy, see also
  2115 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2116 examples.
  2117 
  2118 * Method "induct": improved handling of simultaneous goals. Instead of
  2119 introducing object-level conjunction, the statement is now split into
  2120 several conclusions, while the corresponding symbolic cases are nested
  2121 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2122 see src/HOL/Induct/Common_Patterns.thy, for example.
  2123 
  2124 * Method "induct": mutual induction rules are now specified as a list
  2125 of rule sharing the same induction cases. HOL packages usually provide
  2126 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2127 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2128 mutual induction rules differently, i.e. like this:
  2129 
  2130   (induct rule: foo_bar.inducts)
  2131   (induct set: foo bar)
  2132   (induct pred: foo bar)
  2133   (induct type: foo bar)
  2134 
  2135 The ML function ProjectRule.projections turns old-style rules into the
  2136 new format.
  2137 
  2138 * Method "coinduct": dual of induction, see
  2139 src/HOL/Library/Coinductive_List.thy for various examples.
  2140 
  2141 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2142 considered a legacy feature.
  2143 
  2144 * Attribute "symmetric" produces result with standardized schematic
  2145 variables (index 0).  Potential INCOMPATIBILITY.
  2146 
  2147 * Simplifier: by default the simplifier trace only shows top level
  2148 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2149 default. Thus there is less danger of being flooded by the trace. The
  2150 trace indicates where parts have been suppressed.
  2151   
  2152 * Provers/classical: removed obsolete classical version of elim_format
  2153 attribute; classical elim/dest rules are now treated uniformly when
  2154 manipulating the claset.
  2155 
  2156 * Provers/classical: stricter checks to ensure that supplied intro,
  2157 dest and elim rules are well-formed; dest and elim rules must have at
  2158 least one premise.
  2159 
  2160 * Provers/classical: attributes dest/elim/intro take an optional
  2161 weight argument for the rule (just as the Pure versions).  Weights are
  2162 ignored by automated tools, but determine the search order of single
  2163 rule steps.
  2164 
  2165 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2166 where the body does not mention the bound variable.  Note that dummy
  2167 patterns implicitly depend on their context of bounds, which makes
  2168 "{_. _}" match any set comprehension as expected.  Potential
  2169 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2170 constant "_idtdummy" in the binding position.
  2171 
  2172 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2173 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2174 for example "A -> B" => "Pi A (%_. B)".
  2175 
  2176 * Pure: 'class_deps' command visualizes the subclass relation, using
  2177 the graph browser tool.
  2178 
  2179 * Pure: 'print_theory' now suppresses certain internal declarations by
  2180 default; use '!' option for full details.
  2181 
  2182 
  2183 *** HOL ***
  2184 
  2185 * Method "metis" proves goals by applying the Metis general-purpose
  2186 resolution prover (see also http://gilith.com/software/metis/).
  2187 Examples are in the directory MetisExamples.  WARNING: the
  2188 Isabelle/HOL-Metis integration does not yet work properly with
  2189 multi-threading.
  2190   
  2191 * Command 'sledgehammer' invokes external automatic theorem provers as
  2192 background processes.  It generates calls to the "metis" method if
  2193 successful. These can be pasted into the proof.  Users do not have to
  2194 wait for the automatic provers to return.  WARNING: does not really
  2195 work with multi-threading.
  2196 
  2197 * New "auto_quickcheck" feature tests outermost goal statements for
  2198 potential counter-examples.  Controlled by ML references
  2199 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2200 5000 milliseconds).  Fails silently if statements is outside of
  2201 executable fragment, or any other codgenerator problem occurs.
  2202 
  2203 * New constant "undefined" with axiom "undefined x = undefined".
  2204 
  2205 * Added class "HOL.eq", allowing for code generation with polymorphic
  2206 equality.
  2207 
  2208 * Some renaming of class constants due to canonical name prefixing in
  2209 the new 'class' package:
  2210 
  2211     HOL.abs ~> HOL.abs_class.abs
  2212     HOL.divide ~> HOL.divide_class.divide
  2213     0 ~> HOL.zero_class.zero
  2214     1 ~> HOL.one_class.one
  2215     op + ~> HOL.plus_class.plus
  2216     op - ~> HOL.minus_class.minus
  2217     uminus ~> HOL.minus_class.uminus
  2218     op * ~> HOL.times_class.times
  2219     op < ~> HOL.ord_class.less
  2220     op <= > HOL.ord_class.less_eq
  2221     Nat.power ~> Power.power_class.power
  2222     Nat.size ~> Nat.size_class.size
  2223     Numeral.number_of ~> Numeral.number_class.number_of
  2224     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2225     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2226     Orderings.min ~> Orderings.ord_class.min
  2227     Orderings.max ~> Orderings.ord_class.max
  2228     Divides.op div ~> Divides.div_class.div
  2229     Divides.op mod ~> Divides.div_class.mod
  2230     Divides.op dvd ~> Divides.div_class.dvd
  2231 
  2232 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2233 
  2234 a) User-defined constants using any of the names "plus", "minus",
  2235 "times", "less" or "less_eq". The standard syntax translations for
  2236 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2237 names.
  2238 
  2239 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2240 INCOMPATIBILITY: use more specific names.
  2241 
  2242 c) Permutative equations (e.g. "a + b = b + a")
  2243 Since the change of names also changes the order of terms, permutative
  2244 rewrite rules may get applied in a different order. Experience shows
  2245 that this is rarely the case (only two adaptions in the whole Isabelle
  2246 distribution).  INCOMPATIBILITY: rewrite proofs
  2247 
  2248 d) ML code directly refering to constant names
  2249 This in general only affects hand-written proof tactics, simprocs and
  2250 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2251 Consider using @{const_name} antiquotation.
  2252 
  2253 * New class "default" with associated constant "default".
  2254 
  2255 * Function "sgn" is now overloaded and available on int, real, complex
  2256 (and other numeric types), using class "sgn".  Two possible defs of
  2257 sgn are given as equational assumptions in the classes sgn_if and
  2258 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2259 INCOMPATIBILITY.
  2260 
  2261 * Locale "partial_order" now unified with class "order" (cf. theory
  2262 Orderings), added parameter "less".  INCOMPATIBILITY.
  2263 
  2264 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2265 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2266 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2267 
  2268 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2269 changed order of proof goals in instance proofs.
  2270 
  2271 * The transitivity reasoner for partial and linear orders is set up
  2272 for classes "order" and "linorder".  Instances of the reasoner are available
  2273 in all contexts importing or interpreting the corresponding locales.
  2274 Method "order" invokes the reasoner separately; the reasoner
  2275 is also integrated with the Simplifier as a solver.  Diagnostic
  2276 command 'print_orders' shows the available instances of the reasoner
  2277 in the current context.
  2278 
  2279 * Localized monotonicity predicate in theory "Orderings"; integrated
  2280 lemmas max_of_mono and min_of_mono with this predicate.
  2281 INCOMPATIBILITY.
  2282 
  2283 * Formulation of theorem "dense" changed slightly due to integration
  2284 with new class dense_linear_order.
  2285 
  2286 * Uniform lattice theory development in HOL.
  2287 
  2288     constants "meet" and "join" now named "inf" and "sup"
  2289     constant "Meet" now named "Inf"
  2290 
  2291     classes "meet_semilorder" and "join_semilorder" now named
  2292       "lower_semilattice" and "upper_semilattice"
  2293     class "lorder" now named "lattice"
  2294     class "comp_lat" now named "complete_lattice"
  2295 
  2296     Instantiation of lattice classes allows explicit definitions
  2297     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2298 
  2299   INCOMPATIBILITY.  Theorem renames:
  2300 
  2301     meet_left_le            ~> inf_le1
  2302     meet_right_le           ~> inf_le2
  2303     join_left_le            ~> sup_ge1
  2304     join_right_le           ~> sup_ge2
  2305     meet_join_le            ~> inf_sup_ord
  2306     le_meetI                ~> le_infI
  2307     join_leI                ~> le_supI
  2308     le_meet                 ~> le_inf_iff
  2309     le_join                 ~> ge_sup_conv
  2310     meet_idempotent         ~> inf_idem
  2311     join_idempotent         ~> sup_idem
  2312     meet_comm               ~> inf_commute
  2313     join_comm               ~> sup_commute
  2314     meet_leI1               ~> le_infI1
  2315     meet_leI2               ~> le_infI2
  2316     le_joinI1               ~> le_supI1
  2317     le_joinI2               ~> le_supI2
  2318     meet_assoc              ~> inf_assoc
  2319     join_assoc              ~> sup_assoc
  2320     meet_left_comm          ~> inf_left_commute
  2321     meet_left_idempotent    ~> inf_left_idem
  2322     join_left_comm          ~> sup_left_commute
  2323     join_left_idempotent    ~> sup_left_idem
  2324     meet_aci                ~> inf_aci
  2325     join_aci                ~> sup_aci
  2326     le_def_meet             ~> le_iff_inf
  2327     le_def_join             ~> le_iff_sup
  2328     join_absorp2            ~> sup_absorb2
  2329     join_absorp1            ~> sup_absorb1
  2330     meet_absorp1            ~> inf_absorb1
  2331     meet_absorp2            ~> inf_absorb2
  2332     meet_join_absorp        ~> inf_sup_absorb
  2333     join_meet_absorp        ~> sup_inf_absorb
  2334     distrib_join_le         ~> distrib_sup_le
  2335     distrib_meet_le         ~> distrib_inf_le
  2336 
  2337     add_meet_distrib_left   ~> add_inf_distrib_left
  2338     add_join_distrib_left   ~> add_sup_distrib_left
  2339     is_join_neg_meet        ~> is_join_neg_inf
  2340     is_meet_neg_join        ~> is_meet_neg_sup
  2341     add_meet_distrib_right  ~> add_inf_distrib_right
  2342     add_join_distrib_right  ~> add_sup_distrib_right
  2343     add_meet_join_distribs  ~> add_sup_inf_distribs
  2344     join_eq_neg_meet        ~> sup_eq_neg_inf
  2345     meet_eq_neg_join        ~> inf_eq_neg_sup
  2346     add_eq_meet_join        ~> add_eq_inf_sup
  2347     meet_0_imp_0            ~> inf_0_imp_0
  2348     join_0_imp_0            ~> sup_0_imp_0
  2349     meet_0_eq_0             ~> inf_0_eq_0
  2350     join_0_eq_0             ~> sup_0_eq_0
  2351     neg_meet_eq_join        ~> neg_inf_eq_sup
  2352     neg_join_eq_meet        ~> neg_sup_eq_inf
  2353     join_eq_if              ~> sup_eq_if
  2354 
  2355     mono_meet               ~> mono_inf
  2356     mono_join               ~> mono_sup
  2357     meet_bool_eq            ~> inf_bool_eq
  2358     join_bool_eq            ~> sup_bool_eq
  2359     meet_fun_eq             ~> inf_fun_eq
  2360     join_fun_eq             ~> sup_fun_eq
  2361     meet_set_eq             ~> inf_set_eq
  2362     join_set_eq             ~> sup_set_eq
  2363     meet1_iff               ~> inf1_iff
  2364     meet2_iff               ~> inf2_iff
  2365     meet1I                  ~> inf1I
  2366     meet2I                  ~> inf2I
  2367     meet1D1                 ~> inf1D1
  2368     meet2D1                 ~> inf2D1
  2369     meet1D2                 ~> inf1D2
  2370     meet2D2                 ~> inf2D2
  2371     meet1E                  ~> inf1E
  2372     meet2E                  ~> inf2E
  2373     join1_iff               ~> sup1_iff
  2374     join2_iff               ~> sup2_iff
  2375     join1I1                 ~> sup1I1
  2376     join2I1                 ~> sup2I1
  2377     join1I1                 ~> sup1I1
  2378     join2I2                 ~> sup1I2
  2379     join1CI                 ~> sup1CI
  2380     join2CI                 ~> sup2CI
  2381     join1E                  ~> sup1E
  2382     join2E                  ~> sup2E
  2383 
  2384     is_meet_Meet            ~> is_meet_Inf
  2385     Meet_bool_def           ~> Inf_bool_def
  2386     Meet_fun_def            ~> Inf_fun_def
  2387     Meet_greatest           ~> Inf_greatest
  2388     Meet_lower              ~> Inf_lower
  2389     Meet_set_def            ~> Inf_set_def
  2390 
  2391     Sup_def                 ~> Sup_Inf
  2392     Sup_bool_eq             ~> Sup_bool_def
  2393     Sup_fun_eq              ~> Sup_fun_def
  2394     Sup_set_eq              ~> Sup_set_def
  2395 
  2396     listsp_meetI            ~> listsp_infI
  2397     listsp_meet_eq          ~> listsp_inf_eq
  2398 
  2399     meet_min                ~> inf_min
  2400     join_max                ~> sup_max
  2401 
  2402 * Added syntactic class "size"; overloaded constant "size" now has
  2403 type "'a::size ==> bool"
  2404 
  2405 * Internal reorganisation of `size' of datatypes: size theorems
  2406 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2407 simplification rules by default!); theorems "prod.size" now named
  2408 "*.size".
  2409 
  2410 * Class "div" now inherits from class "times" rather than "type".
  2411 INCOMPATIBILITY.
  2412 
  2413 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2414 Linorder etc.  have disappeared; operations defined in terms of
  2415 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2416 
  2417 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2418 
  2419 * HOL-Word: New extensive library and type for generic, fixed size
  2420 machine words, with arithemtic, bit-wise, shifting and rotating
  2421 operations, reflection into int, nat, and bool lists, automation for
  2422 linear arithmetic (by automatic reflection into nat or int), including
  2423 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2424 arithmetic type classes, supporting automatic simplification of
  2425 numerals on all operations.
  2426 
  2427 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2428 
  2429 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2430 
  2431 * Code generator library theories:
  2432   - Code_Integer represents HOL integers by big integer literals in target
  2433     languages.
  2434   - Code_Char represents HOL characters by character literals in target
  2435     languages.
  2436   - Code_Char_chr like Code_Char, but also offers treatment of character
  2437     codes; includes Code_Integer.
  2438   - Executable_Set allows to generate code for finite sets using lists.
  2439   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2440     denominator).
  2441   - Executable_Real implements a subset of real numbers, namly those
  2442     representable by rational numbers.
  2443   - Efficient_Nat implements natural numbers by integers, which in general will
  2444     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2445     includes Code_Integer.
  2446   - Code_Index provides an additional datatype index which is mapped to
  2447     target-language built-in integers.
  2448   - Code_Message provides an additional datatype message_string which is isomorphic to
  2449     strings; messages are mapped to target-language strings.
  2450 
  2451 * New package for inductive predicates
  2452 
  2453   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2454 
  2455     inductive
  2456       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2457       for z_1 :: U_1 and ... and z_n :: U_m
  2458     where
  2459       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2460     | ...
  2461 
  2462   with full support for type-inference, rather than
  2463 
  2464     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2465 
  2466     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2467     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2468 
  2469     inductive "s z_1 ... z_m"
  2470     intros
  2471       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2472       ...
  2473 
  2474   For backward compatibility, there is a wrapper allowing inductive
  2475   sets to be defined with the new package via
  2476 
  2477     inductive_set
  2478       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2479       for z_1 :: U_1 and ... and z_n :: U_m
  2480     where
  2481       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2482     | ...
  2483 
  2484   or
  2485 
  2486     inductive_set
  2487       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2488       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2489       for z_1 :: U_1 and ... and z_n :: U_m
  2490     where
  2491       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2492     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2493     | ...
  2494 
  2495   if the additional syntax "p ..." is required.
  2496 
  2497   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2498   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2499 
  2500   INCOMPATIBILITIES:
  2501 
  2502   - Since declaration and definition of inductive sets or predicates
  2503     is no longer separated, abbreviations involving the newly
  2504     introduced sets or predicates must be specified together with the
  2505     introduction rules after the 'where' keyword (see above), rather
  2506     than before the actual inductive definition.
  2507 
  2508   - The variables in induction and elimination rules are now
  2509     quantified in the order of their occurrence in the introduction
  2510     rules, rather than in alphabetical order. Since this may break
  2511     some proofs, these proofs either have to be repaired, e.g. by
  2512     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2513     statements of the form
  2514 
  2515       case (rule_i a_i_1 ... a_i_{k_i})
  2516 
  2517     or the old order of quantification has to be restored by explicitly adding
  2518     meta-level quantifiers in the introduction rules, i.e.
  2519 
  2520       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2521 
  2522   - The format of the elimination rules is now
  2523 
  2524       p z_1 ... z_m x_1 ... x_n ==>
  2525         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2526         ==> ... ==> P
  2527 
  2528     for predicates and
  2529 
  2530       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2531         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2532         ==> ... ==> P
  2533 
  2534     for sets rather than
  2535 
  2536       x : s z_1 ... z_m ==>
  2537         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2538         ==> ... ==> P
  2539 
  2540     This may require terms in goals to be expanded to n-tuples
  2541     (e.g. using case_tac or simplification with the split_paired_all
  2542     rule) before the above elimination rule is applicable.
  2543 
  2544   - The elimination or case analysis rules for (mutually) inductive
  2545     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2546     list of rules "p_1_..._p_k.elims" is no longer available.
  2547 
  2548 * New package "function"/"fun" for general recursive functions,
  2549 supporting mutual and nested recursion, definitions in local contexts,
  2550 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2551 for small examples, and the separate tutorial on the function
  2552 package. The old recdef "package" is still available as before, but
  2553 users are encouraged to use the new package.
  2554 
  2555 * Method "lexicographic_order" automatically synthesizes termination
  2556 relations as lexicographic combinations of size measures. 
  2557 
  2558 * Case-expressions allow arbitrary constructor-patterns (including
  2559 "_") and take their order into account, like in functional
  2560 programming.  Internally, this is translated into nested
  2561 case-expressions; missing cases are added and mapped to the predefined
  2562 constant "undefined". In complicated cases printing may no longer show
  2563 the original input but the internal form. Lambda-abstractions allow
  2564 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2565 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2566 variable.
  2567 
  2568 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2569 is an abbreviation for "of_nat :: nat => int". The simplification
  2570 rules for "of_nat" have been changed to work like "int" did
  2571 previously.  Potential INCOMPATIBILITY:
  2572   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2573   - of_nat_diff and of_nat_mult are no longer default simp rules
  2574 
  2575 * Method "algebra" solves polynomial equations over (semi)rings using
  2576 Groebner bases. The (semi)ring structure is defined by locales and the
  2577 tool setup depends on that generic context. Installing the method for
  2578 a specific type involves instantiating the locale and possibly adding
  2579 declarations for computation on the coefficients.  The method is
  2580 already instantiated for natural numbers and for the axiomatic class
  2581 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2582 CALCULEMUS 2007 for the general principles underlying this
  2583 architecture of context-aware proof-tools.
  2584 
  2585 * Method "ferrack" implements quantifier elimination over
  2586 special-purpose dense linear orders using locales (analogous to
  2587 "algebra"). The method is already installed for class
  2588 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2589 rat, etc.
  2590 
  2591 * Former constant "List.op @" now named "List.append".  Use ML
  2592 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2593 circumvent possible incompatibilities when working on ML level.
  2594 
  2595 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2596 
  2597 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2598 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2599 
  2600 * New syntax for Haskell-like list comprehension (input only), eg.
  2601 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2602 
  2603 * The special syntax for function "filter" has changed from [x :
  2604 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2605 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2606 
  2607 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2608 defined on nat only, as an abbreviation for [a..<Suc b]
  2609 INCOMPATIBILITY.
  2610 
  2611 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2612 
  2613 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2614 
  2615 * New lemma collection field_simps (an extension of ring_simps) for
  2616 manipulating (in)equations involving division. Multiplies with all
  2617 denominators that can be proved to be non-zero (in equations) or
  2618 positive/negative (in inequations).
  2619 
  2620 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2621 have been improved and renamed to ring_simps, group_simps and
  2622 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2623 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2624 
  2625 * Theory Library/Commutative_Ring: switched from recdef to function
  2626 package; constants add, mul, pow now curried.  Infix syntax for
  2627 algebraic operations.
  2628 
  2629 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2630 INCOMPATIBILITY.
  2631 
  2632 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2633 INCOMPATIBILITY.
  2634 
  2635 * HOL/records: generalised field-update to take a function on the
  2636 field rather than the new value: r(|A := x|) is translated to A_update
  2637 (K x) r The K-combinator that is internally used is called K_record.
  2638 INCOMPATIBILITY: Usage of the plain update functions has to be
  2639 adapted.
  2640  
  2641 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2642 * x = 0, which are required for a semiring.  Richer structures do not
  2643 inherit from semiring_0 anymore, because this property is a theorem
  2644 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2645 there is more to prove, but this is mostly trivial.
  2646 
  2647 * Class "recpower" is generalized to arbitrary monoids, not just
  2648 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2649 commutativity or semiring properties additionally.
  2650 
  2651 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2652 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2653 better use 'abbreviation'.
  2654 
  2655 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2656 
  2657 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2658 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2659 significant changes for setting up numeral syntax for types:
  2660   - New constants Numeral.pred and Numeral.succ instead
  2661       of former Numeral.bin_pred and Numeral.bin_succ.
  2662   - Use integer operations instead of bin_add, bin_mult and so on.
  2663   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2664   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2665 
  2666 See src/HOL/Integ/IntArith.thy for an example setup.
  2667 
  2668 * Command 'normal_form' computes the normal form of a term that may
  2669 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2670 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2671 heavy-duty computations because the functions are compiled to ML
  2672 first.  Correspondingly, a method "normalization" is provided.  See
  2673 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2674 
  2675 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2676 25 like -->); output depends on the "iff" print_mode, the default is
  2677 "A = B" (with priority 50).
  2678 
  2679 * Relations less (<) and less_eq (<=) are also available on type bool.
  2680 Modified syntax to disallow nesting without explicit parentheses,
  2681 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2682 INCOMPATIBILITY.
  2683 
  2684 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2685 
  2686 * Relation composition operator "op O" now has precedence 75 and binds
  2687 stronger than union and intersection. INCOMPATIBILITY.
  2688 
  2689 * The old set interval syntax "{m..n(}" (and relatives) has been
  2690 removed.  Use "{m..<n}" (and relatives) instead.
  2691 
  2692 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2693 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2694 ``declare [[simproc del: neq]]''.
  2695 
  2696 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2697 True/False.
  2698 
  2699 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2700 
  2701 * Theorem setsum_mult renamed to setsum_right_distrib.
  2702 
  2703 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2704 ``rule'' method.
  2705 
  2706 * Reimplemented methods "sat" and "satx", with several improvements:
  2707 goals no longer need to be stated as "<prems> ==> False", equivalences
  2708 (i.e. "=" on type bool) are handled, variable names of the form
  2709 "lit_<n>" are no longer reserved, significant speedup.
  2710 
  2711 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2712 zChaff is still supported as well.
  2713 
  2714 * 'inductive' and 'datatype': provide projections of mutual rules,
  2715 bundled as foo_bar.inducts;
  2716 
  2717 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2718 Library.
  2719 
  2720 * Library: moved theory Accessible_Part to main HOL.
  2721 
  2722 * Library: added theory Coinductive_List of potentially infinite lists
  2723 as greatest fixed-point.
  2724 
  2725 * Library: added theory AssocList which implements (finite) maps as
  2726 association lists.
  2727 
  2728 * Method "evaluation" solves goals (i.e. a boolean expression)
  2729 efficiently by compiling it to ML.  The goal is "proved" (via an
  2730 oracle) if it evaluates to True.
  2731 
  2732 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2733 also when invoked by the simplifier.  This results in the Simplifier
  2734 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2735 Configuration option fast_arith_split_limit=0 recovers the old
  2736 behavior.
  2737 
  2738 * Support for hex (0x20) and binary (0b1001) numerals.
  2739 
  2740 * New method: reify eqs (t), where eqs are equations for an
  2741 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2742 parameter, computes a term s::'b and a list xs::'a list and proves the
  2743 theorem I xs s = t. This is also known as reification or quoting. The
  2744 resulting theorem is applied to the subgoal to substitute t with I xs
  2745 s.  If t is omitted, the subgoal itself is reified.
  2746 
  2747 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2748 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2749 where f is supposed to be a computable function (in the sense of code
  2750 generattion). The method uses reify to compute s and xs as above then
  2751 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2752 r and finally gets the theorem t = r, which is again applied to the
  2753 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2754 
  2755 * Reflection: Automatic reification now handels binding, an example is
  2756 available in src/HOL/ex/ReflectionEx.thy
  2757 
  2758 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2759 command 'statespace' that is similar to 'record', but introduces an
  2760 abstract specification based on the locale infrastructure instead of
  2761 HOL types.  This leads to extra flexibility in composing state spaces,
  2762 in particular multiple inheritance and renaming of components.
  2763 
  2764 
  2765 *** HOL-Complex ***
  2766 
  2767 * Hyperreal: Functions root and sqrt are now defined on negative real
  2768 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2769 Nonnegativity side conditions have been removed from many lemmas, so
  2770 that more subgoals may now be solved by simplification; potential
  2771 INCOMPATIBILITY.
  2772 
  2773 * Real: new type classes formalize real normed vector spaces and
  2774 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2775 and norm :: 'a => real.
  2776 
  2777 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2778 reals into other types. The overloaded constant Reals :: 'a set is now
  2779 defined as range of_real; potential INCOMPATIBILITY.
  2780 
  2781 * Real: proper support for ML code generation, including 'quickcheck'.
  2782 Reals are implemented as arbitrary precision rationals.
  2783 
  2784 * Hyperreal: Several constants that previously worked only for the
  2785 reals have been generalized, so they now work over arbitrary vector
  2786 spaces. Type annotations may need to be added in some cases; potential
  2787 INCOMPATIBILITY.
  2788 
  2789   Infinitesimal  :: ('a::real_normed_vector) star set
  2790   HFinite        :: ('a::real_normed_vector) star set
  2791   HInfinite      :: ('a::real_normed_vector) star set
  2792   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2793   monad          :: ('a::real_normed_vector) star => 'a star set
  2794   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2795   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2796   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2797   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2798   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2799   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2800   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2801   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2802   sgn            :: 'a::real_normed_vector => 'a
  2803   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2804 
  2805 * Complex: Some complex-specific constants are now abbreviations for
  2806 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2807 hnorm.  Other constants have been entirely removed in favor of the
  2808 polymorphic versions (INCOMPATIBILITY):
  2809 
  2810   approx        <-- capprox
  2811   HFinite       <-- CFinite
  2812   HInfinite     <-- CInfinite
  2813   Infinitesimal <-- CInfinitesimal
  2814   monad         <-- cmonad
  2815   galaxy        <-- cgalaxy
  2816   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2817   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2818   (ns)deriv     <-- (ns)cderiv
  2819 
  2820 
  2821 *** HOL-Algebra ***
  2822 
  2823 * Formalisation of ideals and the quotient construction over rings.
  2824 
  2825 * Order and lattice theory no longer based on records.
  2826 INCOMPATIBILITY.
  2827 
  2828 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2829 greatest_closed.  INCOMPATIBILITY.
  2830 
  2831 * Method algebra is now set up via an attribute.  For examples see
  2832 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2833 of algebraic structures.
  2834 
  2835 * Renamed theory CRing to Ring.
  2836 
  2837 
  2838 *** HOL-Nominal ***
  2839 
  2840 * Substantial, yet incomplete support for nominal datatypes (binding
  2841 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2842 src/HOL/Nominal/Examples.  Prospective users should consult
  2843 http://isabelle.in.tum.de/nominal/
  2844 
  2845 
  2846 *** ML ***
  2847 
  2848 * ML basics: just one true type int, which coincides with IntInf.int
  2849 (even on SML/NJ).
  2850 
  2851 * ML within Isar: antiquotations allow to embed statically-checked
  2852 formal entities in the source, referring to the context available at
  2853 compile-time.  For example:
  2854 
  2855 ML {* @{sort "{zero,one}"} *}
  2856 ML {* @{typ "'a => 'b"} *}
  2857 ML {* @{term "%x. x"} *}
  2858 ML {* @{prop "x == y"} *}
  2859 ML {* @{ctyp "'a => 'b"} *}
  2860 ML {* @{cterm "%x. x"} *}
  2861 ML {* @{cprop "x == y"} *}
  2862 ML {* @{thm asm_rl} *}
  2863 ML {* @{thms asm_rl} *}
  2864 ML {* @{type_name c} *}
  2865 ML {* @{type_syntax c} *}
  2866 ML {* @{const_name c} *}
  2867 ML {* @{const_syntax c} *}
  2868 ML {* @{context} *}
  2869 ML {* @{theory} *}
  2870 ML {* @{theory Pure} *}
  2871 ML {* @{theory_ref} *}
  2872 ML {* @{theory_ref Pure} *}
  2873 ML {* @{simpset} *}
  2874 ML {* @{claset} *}
  2875 ML {* @{clasimpset} *}
  2876 
  2877 The same works for sources being ``used'' within an Isar context.
  2878 
  2879 * ML in Isar: improved error reporting; extra verbosity with
  2880 ML_Context.trace enabled.
  2881 
  2882 * Pure/General/table.ML: the join operations now works via exceptions
  2883 DUP/SAME instead of type option. This is simpler in simple cases, and
  2884 admits slightly more efficient complex applications.
  2885 
  2886 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2887 use Context.generic instead of just theory.
  2888 
  2889 * Pure: datatype Context.generic joins theory/Proof.context and
  2890 provides some facilities for code that works in either kind of
  2891 context, notably GenericDataFun for uniform theory and proof data.
  2892 
  2893 * Pure: simplified internal attribute type, which is now always
  2894 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2895 local (Proof.context) attributes have been discontinued, while
  2896 minimizing code duplication. Thm.rule_attribute and
  2897 Thm.declaration_attribute build canonical attributes; see also structure
  2898 Context for further operations on Context.generic, notably
  2899 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2900 declarations and definitions.
  2901 
  2902 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2903 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2904 init only required for impure data. INCOMPATIBILITY: empty really need
  2905 to be empty (no dependencies on theory content!)
  2906 
  2907 * Pure/kernel: consts certification ignores sort constraints given in
  2908 signature declarations. (This information is not relevant to the
  2909 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2910 potential INCOMPATIBILITY.
  2911 
  2912 * Pure: axiomatic type classes are now purely definitional, with
  2913 explicit proofs of class axioms and super class relations performed
  2914 internally. See Pure/axclass.ML for the main internal interfaces --
  2915 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2916 AxClass.axiomatize_class/classrel/arity supersede
  2917 Sign.add_classes/classrel/arities.
  2918 
  2919 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2920 global/local versions on theory vs. Proof.context have been
  2921 discontinued; Attrib.syntax and Method.syntax have been adapted
  2922 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2923 attributes, methods, etc.
  2924 
  2925 * Pure: several functions of signature "... -> theory -> theory * ..."
  2926 have been reoriented to "... -> theory -> ... * theory" in order to
  2927 allow natural usage in combination with the ||>, ||>>, |-> and
  2928 fold_map combinators.
  2929 
  2930 * Pure: official theorem names (closed derivations) and additional
  2931 comments (tags) are now strictly separate.  Name hints -- which are
  2932 maintained as tags -- may be attached any time without affecting the
  2933 derivation.
  2934 
  2935 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2936 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2937 achieve the old behaviour.
  2938 
  2939 * Pure: the "Goal" constant is now called "prop", supporting a
  2940 slightly more general idea of ``protecting'' meta-level rule
  2941 statements.
  2942 
  2943 * Pure: Logic.(un)varify only works in a global context, which is now
  2944 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2945 Logic.legacy_(un)varify as temporary workaround.
  2946 
  2947 * Pure: structure Name provides scalable operations for generating
  2948 internal variable names, notably Name.variants etc.  This replaces
  2949 some popular functions from term.ML:
  2950 
  2951   Term.variant		->  Name.variant
  2952   Term.variantlist	->  Name.variant_list
  2953   Term.invent_names	->  Name.invent_list
  2954 
  2955 Note that low-level renaming rarely occurs in new code -- operations
  2956 from structure Variable are used instead (see below).
  2957 
  2958 * Pure: structure Variable provides fundamental operations for proper
  2959 treatment of fixed/schematic variables in a context.  For example,
  2960 Variable.import introduces fixes for schematics of given facts and
  2961 Variable.export reverses the effect (up to renaming) -- this replaces
  2962 various freeze_thaw operations.
  2963 
  2964 * Pure: structure Goal provides simple interfaces for
  2965 init/conclude/finish and tactical prove operations (replacing former
  2966 Tactic.prove).  Goal.prove is the canonical way to prove results
  2967 within a given context; Goal.prove_global is a degraded version for
  2968 theory level goals, including a global Drule.standard.  Note that
  2969 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2970 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2971 in a locale context).
  2972 
  2973 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2974 and type checking (Syntax.check_term etc.), with common combinations
  2975 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2976 which are considered legacy and await removal.
  2977 
  2978 * Pure/Syntax: generic interfaces for type unchecking
  2979 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2980 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2981 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2982 available for convenience, but refer to the very same operations using
  2983 a mere theory instead of a full context.
  2984 
  2985 * Isar: simplified treatment of user-level errors, using exception
  2986 ERROR of string uniformly.  Function error now merely raises ERROR,
  2987 without any side effect on output channels.  The Isar toplevel takes
  2988 care of proper display of ERROR exceptions.  ML code may use plain
  2989 handle/can/try; cat_error may be used to concatenate errors like this:
  2990 
  2991   ... handle ERROR msg => cat_error msg "..."
  2992 
  2993 Toplevel ML code (run directly or through the Isar toplevel) may be
  2994 embedded into the Isar toplevel with exception display/debug like
  2995 this:
  2996 
  2997   Isar.toplevel (fn () => ...)
  2998 
  2999 INCOMPATIBILITY, removed special transform_error facilities, removed
  3000 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3001 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3002 -- use plain ERROR instead.
  3003 
  3004 * Isar: theory setup now has type (theory -> theory), instead of a
  3005 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3006 
  3007 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3008 ProofContext.debug/verbose flags.
  3009 
  3010 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3011 theory before entering a proof state.  Transactions now always see a
  3012 quasi-functional intermediate checkpoint, both in interactive and
  3013 batch mode.
  3014 
  3015 * Isar: simplified interfaces for outer syntax.  Renamed
  3016 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3017 OuterSyntax.add_parsers -- this functionality is now included in
  3018 OuterSyntax.command etc.  INCOMPATIBILITY.
  3019 
  3020 * Simplifier: the simpset of a running simplification process now
  3021 contains a proof context (cf. Simplifier.the_context), which is the
  3022 very context that the initial simpset has been retrieved from (by
  3023 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3024 (solver, looper etc.) may depend on arbitrary proof data.
  3025 
  3026 * Simplifier.inherit_context inherits the proof context (plus the
  3027 local bounds) of the current simplification process; any simproc
  3028 etc. that calls the Simplifier recursively should do this!  Removed
  3029 former Simplifier.inherit_bounds, which is already included here --
  3030 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3031 specify an explicit context using Simplifier.context/theory_context.
  3032 
  3033 * Simplifier/Classical Reasoner: more abstract interfaces
  3034 change_simpset/claset for modifying the simpset/claset reference of a
  3035 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3036 INCOMPATIBILITY.
  3037 
  3038 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3039 "Trueprop" etc.
  3040 
  3041 
  3042 *** System ***
  3043 
  3044 * settings: the default heap location within ISABELLE_HOME_USER now
  3045 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3046 Isabelle installations.
  3047 
  3048 * isabelle-process: option -S (secure mode) disables some critical
  3049 operations, notably runtime compilation and evaluation of ML source
  3050 code.
  3051 
  3052 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3053 
  3054 * Support for parallel execution, using native multicore support of
  3055 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3056 independent theories, according to the given theory header
  3057 specifications. The maximum number of worker threads is specified via
  3058 usedir option -M or the "max-threads" setting in Proof General. A
  3059 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3060 to 6 on a 8-core machine.  User-code needs to observe certain
  3061 guidelines for thread-safe programming, see appendix A in the Isar
  3062 Implementation manual.
  3063 
  3064 
  3065 
  3066 New in Isabelle2005 (October 2005)
  3067 ----------------------------------
  3068 
  3069 *** General ***
  3070 
  3071 * Theory headers: the new header syntax for Isar theories is
  3072 
  3073   theory <name>
  3074   imports <theory1> ... <theoryN>
  3075   uses <file1> ... <fileM>
  3076   begin
  3077 
  3078 where the 'uses' part is optional.  The previous syntax
  3079 
  3080   theory <name> = <theory1> + ... + <theoryN>:
  3081 
  3082 will disappear in the next release.  Use isatool fixheaders to convert
  3083 existing theory files.  Note that there is no change in ancient
  3084 non-Isar theories now, but these will disappear soon.
  3085 
  3086 * Theory loader: parent theories can now also be referred to via
  3087 relative and absolute paths.
  3088 
  3089 * Command 'find_theorems' searches for a list of criteria instead of a
  3090 list of constants. Known criteria are: intro, elim, dest, name:string,
  3091 simp:term, and any term. Criteria can be preceded by '-' to select
  3092 theorems that do not match. Intro, elim, dest select theorems that
  3093 match the current goal, name:s selects theorems whose fully qualified
  3094 name contain s, and simp:term selects all simplification rules whose
  3095 lhs match term.  Any other term is interpreted as pattern and selects
  3096 all theorems matching the pattern. Available in ProofGeneral under
  3097 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3098 
  3099   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3100 
  3101 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3102 matching the current goal as introduction rule and not having "HOL."
  3103 in their name (i.e. not being defined in theory HOL).
  3104 
  3105 * Command 'thms_containing' has been discontinued in favour of
  3106 'find_theorems'; INCOMPATIBILITY.
  3107 
  3108 * Communication with Proof General is now 8bit clean, which means that
  3109 Unicode text in UTF-8 encoding may be used within theory texts (both
  3110 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3111 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3112 
  3113   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3114   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3115 
  3116 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3117 Classical Reasoner.  Typical big applications run around 2 times
  3118 faster.
  3119 
  3120 
  3121 *** Document preparation ***
  3122 
  3123 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3124 of raw sources.  Only those symbols that do not require additional
  3125 LaTeX packages (depending on comments in isabellesym.sty) are
  3126 displayed properly, everything else is left verbatim.  isatool display
  3127 and isatool print are used as front ends (these are subject to the
  3128 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3129 
  3130 * Command tags control specific markup of certain regions of text,
  3131 notably folding and hiding.  Predefined tags include "theory" (for
  3132 theory begin and end), "proof" for proof commands, and "ML" for
  3133 commands involving ML code; the additional tags "visible" and
  3134 "invisible" are unused by default.  Users may give explicit tag
  3135 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3136 interpretation of tags is determined by the LaTeX job during document
  3137 preparation: see option -V of isatool usedir, or options -n and -t of
  3138 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3139 \isadroptag.
  3140 
  3141 Several document versions may be produced at the same time via isatool
  3142 usedir (the generated index.html will link all of them).  Typical
  3143 specifications include ''-V document=theory,proof,ML'' to present
  3144 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3145 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3146 these parts without any formal replacement text.  The Isabelle site
  3147 default settings produce ''document'' and ''outline'' versions as
  3148 specified above.
  3149 
  3150 * Several new antiquotations:
  3151 
  3152   @{term_type term} prints a term with its type annotated;
  3153 
  3154   @{typeof term} prints the type of a term;
  3155 
  3156   @{const const} is the same as @{term const}, but checks that the
  3157   argument is a known logical constant;
  3158 
  3159   @{term_style style term} and @{thm_style style thm} print a term or
  3160   theorem applying a "style" to it
  3161 
  3162   @{ML text}
  3163 
  3164 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3165 definitions, equations, inequations etc., 'concl' printing only the
  3166 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3167 to print the specified premise.  TermStyle.add_style provides an ML
  3168 interface for introducing further styles.  See also the "LaTeX Sugar"
  3169 document practical applications.  The ML antiquotation prints
  3170 type-checked ML expressions verbatim.
  3171 
  3172 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3173 and 'text' support optional locale specification '(in loc)', which
  3174 specifies the default context for interpreting antiquotations.  For
  3175 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3176 
  3177 * Option 'locale=NAME' of antiquotations specifies an alternative
  3178 context interpreting the subsequent argument.  For example: @{thm
  3179 [locale=lattice] inf_assoc}.
  3180 
  3181 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3182 a proof context.
  3183 
  3184 * Proper output of antiquotations for theory commands involving a
  3185 proof context (such as 'locale' or 'theorem (in loc) ...').
  3186 
  3187 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3188 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3189 
  3190 * isatool usedir: new option -C (default true) controls whether option
  3191 -D should include a copy of the original document directory; -C false
  3192 prevents unwanted effects such as copying of administrative CVS data.
  3193 
  3194 
  3195 *** Pure ***
  3196 
  3197 * Considerably improved version of 'constdefs' command.  Now performs
  3198 automatic type-inference of declared constants; additional support for
  3199 local structure declarations (cf. locales and HOL records), see also
  3200 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3201 sequential dependencies of definitions within a single 'constdefs'
  3202 section; moreover, the declared name needs to be an identifier.  If
  3203 all fails, consider to fall back on 'consts' and 'defs' separately.
  3204 
  3205 * Improved indexed syntax and implicit structures.  First of all,
  3206 indexed syntax provides a notational device for subscripted
  3207 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3208 expressions.  Secondly, in a local context with structure
  3209 declarations, number indexes \<^sub>n or the empty index (default
  3210 number 1) refer to a certain fixed variable implicitly; option
  3211 show_structs controls printing of implicit structures.  Typical
  3212 applications of these concepts involve record types and locales.
  3213 
  3214 * New command 'no_syntax' removes grammar declarations (and
  3215 translations) resulting from the given syntax specification, which is
  3216 interpreted in the same manner as for the 'syntax' command.
  3217 
  3218 * 'Advanced' translation functions (parse_translation etc.) may depend
  3219 on the signature of the theory context being presently used for
  3220 parsing/printing, see also isar-ref manual.
  3221 
  3222 * Improved 'oracle' command provides a type-safe interface to turn an
  3223 ML expression of type theory -> T -> term into a primitive rule of
  3224 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3225 is already included here); see also FOL/ex/IffExample.thy;
  3226 INCOMPATIBILITY.
  3227 
  3228 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3229 before); "cI" is no longer bound, use "c.intro" instead.
  3230 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3231 axclasses vs. locales.
  3232 
  3233 * Improved internal renaming of symbolic identifiers -- attach primes
  3234 instead of base 26 numbers.
  3235 
  3236 * New flag show_question_marks controls printing of leading question
  3237 marks in schematic variable names.
  3238 
  3239 * In schematic variable names, *any* symbol following \<^isub> or
  3240 \<^isup> is now treated as part of the base name.  For example, the
  3241 following works without printing of awkward ".0" indexes:
  3242 
  3243   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3244     by simp
  3245 
  3246 * Inner syntax includes (*(*nested*) comments*).
  3247 
  3248 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3249 annotations as "(00...)".
  3250 
  3251 * Clear separation of logical types and nonterminals, where the latter
  3252 may only occur in 'syntax' specifications or type abbreviations.
  3253 Before that distinction was only partially implemented via type class
  3254 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3255 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3256 exotic syntax specifications may require further adaption
  3257 (e.g. Cube/Cube.thy).
  3258 
  3259 * Removed obsolete type class "logic", use the top sort {} instead.
  3260 Note that non-logical types should be declared as 'nonterminals'
  3261 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3262 specifications.
  3263 
  3264 * Attributes 'induct' and 'cases': type or set names may now be
  3265 locally fixed variables as well.
  3266 
  3267 * Simplifier: can now control the depth to which conditional rewriting
  3268 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3269 Limit.
  3270 
  3271 * Simplifier: simplification procedures may now take the current
  3272 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3273 interface), which is very useful for calling the Simplifier
  3274 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3275 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3276 low-level mk_simproc no longer applies Logic.varify internally, to
  3277 allow for use in a context of fixed variables.
  3278 
  3279 * thin_tac now works even if the assumption being deleted contains !!
  3280 or ==>.  More generally, erule now works even if the major premise of
  3281 the elimination rule contains !! or ==>.
  3282 
  3283 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3284 
  3285 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3286 from Pure, which contains all common declarations already.  Both
  3287 theories are defined via plain Isabelle/Isar .thy files.
  3288 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3289 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3290 use isatool fixcpure to adapt your theory and ML sources.
  3291 
  3292 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3293 selections of theorems in named facts via index ranges.
  3294 
  3295 * 'print_theorems': in theory mode, really print the difference
  3296 wrt. the last state (works for interactive theory development only),
  3297 in proof mode print all local facts (cf. 'print_facts');
  3298 
  3299 * 'hide': option '(open)' hides only base names.
  3300 
  3301 * More efficient treatment of intermediate checkpoints in interactive
  3302 theory development.
  3303 
  3304 * Code generator is now invoked via code_module (incremental code
  3305 generation) and code_library (modular code generation, ML structures
  3306 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3307 must be quoted when used as identifiers.
  3308 
  3309 * New 'value' command for reading, evaluating and printing terms using
  3310 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3311 quoted when used as identifier.
  3312 
  3313 
  3314 *** Locales ***
  3315 
  3316 * New commands for the interpretation of locale expressions in
  3317 theories (1), locales (2) and proof contexts (3).  These generate
  3318 proof obligations from the expression specification.  After the
  3319 obligations have been discharged, theorems of the expression are added
  3320 to the theory, target locale or proof context.  The synopsis of the
  3321 commands is a follows:
  3322 
  3323   (1) interpretation expr inst
  3324   (2) interpretation target < expr
  3325   (3) interpret expr inst
  3326 
  3327 Interpretation in theories and proof contexts require a parameter
  3328 instantiation of terms from the current context.  This is applied to
  3329 specifications and theorems of the interpreted expression.
  3330 Interpretation in locales only permits parameter renaming through the
  3331 locale expression.  Interpretation is smart in that interpretations
  3332 that are active already do not occur in proof obligations, neither are
  3333 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3334 inspect active interpretations of a particular locale.  For details,
  3335 see the Isar Reference manual.  Examples can be found in
  3336 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3337 
  3338 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3339 'interpret' instead.
  3340 
  3341 * New context element 'constrains' for adding type constraints to
  3342 parameters.
  3343 
  3344 * Context expressions: renaming of parameters with syntax
  3345 redeclaration.
  3346 
  3347 * Locale declaration: 'includes' disallowed.
  3348 
  3349 * Proper static binding of attribute syntax -- i.e. types / terms /
  3350 facts mentioned as arguments are always those of the locale definition
  3351 context, independently of the context of later invocations.  Moreover,
  3352 locale operations (renaming and type / term instantiation) are applied
  3353 to attribute arguments as expected.
  3354 
  3355 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3356 actual attributes; rare situations may require Attrib.attribute to
  3357 embed those attributes into Attrib.src that lack concrete syntax.
  3358 Attribute implementations need to cooperate properly with the static
  3359 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3360 Attrib.XXX_thm etc. already do the right thing without further
  3361 intervention.  Only unusual applications -- such as "where" or "of"
  3362 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3363 on the context and the facts involved -- may have to assign parsed
  3364 values to argument tokens explicitly.
  3365 
  3366 * Changed parameter management in theorem generation for long goal
  3367 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3368 theorem statement in rare situations.
  3369 
  3370 * Locale inspection command 'print_locale' omits notes elements.  Use
  3371 'print_locale!' to have them included in the output.
  3372 
  3373 
  3374 *** Provers ***
  3375 
  3376 * Provers/hypsubst.ML: improved version of the subst method, for
  3377 single-step rewriting: it now works in bound variable contexts. New is
  3378 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3379 rewrite a different subterm than the original subst method, which is
  3380 still available as 'simplesubst'.
  3381 
  3382 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3383 and quasi orders.
  3384 
  3385 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3386 reflexive-transitive closure of relations.
  3387 
  3388 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3389 limit (previously hard-coded with a value of 20) user-definable.
  3390 
  3391 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3392 is peformed already.  Object-logics merely need to finish their
  3393 initial simpset configuration as before.  INCOMPATIBILITY.
  3394 
  3395 
  3396 *** HOL ***
  3397 
  3398 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3399 
  3400   syntax (epsilon)
  3401     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3402 
  3403 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3404 and x-symbol; use option '-m epsilon' to get it actually printed.
  3405 Moreover, the mathematically important symbolic identifier \<epsilon>
  3406 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3407 
  3408 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3409 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3410 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3411 support corresponding Isar calculations.
  3412 
  3413 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3414 instead of ":".
  3415 
  3416 * theory SetInterval: changed the syntax for open intervals:
  3417 
  3418   Old       New
  3419   {..n(}    {..<n}
  3420   {)n..}    {n<..}
  3421   {m..n(}   {m..<n}
  3422   {)m..n}   {m<..n}
  3423   {)m..n(}  {m<..<n}
  3424 
  3425 The old syntax is still supported but will disappear in the next
  3426 release.  For conversion use the following Emacs search and replace
  3427 patterns (these are not perfect but work quite well):
  3428 
  3429   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3430   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3431 
  3432 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3433 equalities in commutative rings; method 'algebra' provides a generic
  3434 interface.
  3435 
  3436 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3437 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3438 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3439 be a tuple pattern.
  3440 
  3441 Some new syntax forms are available:
  3442 
  3443   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3444   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3445   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3446   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3447 
  3448 The latter form "\<Sum>x < k. e" used to be based on a separate
  3449 function "Summation", which has been discontinued.
  3450 
  3451 * theory Finite_Set: in structured induction proofs, the insert case
  3452 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3453 (insert F x)'.
  3454 
  3455 * The 'refute' command has been extended to support a much larger
  3456 fragment of HOL, including axiomatic type classes, constdefs and
  3457 typedefs, inductive datatypes and recursion.
  3458 
  3459 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3460 Requires zChaff with proof generation to be installed.  See
  3461 HOL/ex/SAT_Examples.thy for examples.
  3462 
  3463 * Datatype induction via method 'induct' now preserves the name of the
  3464 induction variable. For example, when proving P(xs::'a list) by
  3465 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3466 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3467 in unstructured proof scripts.
  3468 
  3469 * Reworked implementation of records.  Improved scalability for
  3470 records with many fields, avoiding performance problems for type
  3471 inference. Records are no longer composed of nested field types, but
  3472 of nested extension types. Therefore the record type only grows linear
  3473 in the number of extensions and not in the number of fields.  The
  3474 top-level (users) view on records is preserved.  Potential
  3475 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3476 old record representation. The type generated for a record is called
  3477 <record_name>_ext_type.
  3478 
  3479 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3480 proofs triggered by a record definition or a simproc (if
  3481 quick_and_dirty is enabled).  Definitions of large records can take
  3482 quite long.
  3483 
  3484 New simproc record_upd_simproc for simplification of multiple record
  3485 updates enabled by default.  Moreover, trivial updates are also
  3486 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3487 occasionally, since simplification is more powerful by default.
  3488 
  3489 * typedef: proper support for polymorphic sets, which contain extra
  3490 type-variables in the term.
  3491 
  3492 * Simplifier: automatically reasons about transitivity chains
  3493 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3494 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3495 old proofs break occasionally as simplification may now solve more
  3496 goals than previously.
  3497 
  3498 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3499 present.  Works for all partial orders (class "order"), in particular
  3500 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3501 just like y <= x.
  3502 
  3503 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3504 bound variable or a constant then the let is unfolded.  Otherwise
  3505 first a is simplified to b, and then f b is simplified to g. If
  3506 possible we abstract b from g arriving at "let x = b in h x",
  3507 otherwise we unfold the let and arrive at g.  The simproc can be
  3508 enabled/disabled by the reference use_let_simproc.  Potential
  3509 INCOMPATIBILITY since simplification is more powerful by default.
  3510 
  3511 * Classical reasoning: the meson method now accepts theorems as arguments.
  3512 
  3513 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3514 jobs to provide advice on the provability of subgoals.
  3515 
  3516 * Theory OrderedGroup and Ring_and_Field: various additions and
  3517 improvements to faciliate calculations involving equalities and
  3518 inequalities.
  3519 
  3520 The following theorems have been eliminated or modified
  3521 (INCOMPATIBILITY):
  3522 
  3523   abs_eq             now named abs_of_nonneg
  3524   abs_of_ge_0        now named abs_of_nonneg
  3525   abs_minus_eq       now named abs_of_nonpos
  3526   imp_abs_id         now named abs_of_nonneg
  3527   imp_abs_neg_id     now named abs_of_nonpos
  3528   mult_pos           now named mult_pos_pos
  3529   mult_pos_le        now named mult_nonneg_nonneg
  3530   mult_pos_neg_le    now named mult_nonneg_nonpos
  3531   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3532   mult_neg           now named mult_neg_neg
  3533   mult_neg_le        now named mult_nonpos_nonpos
  3534 
  3535 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3536      
  3537      zero_le_square
  3538      not_square_less_zero 
  3539 
  3540   The following lemmas have been deleted from Real/RealPow:
  3541   
  3542      realpow_zero_zero
  3543      realpow_two
  3544      realpow_less
  3545      zero_le_power
  3546      realpow_two_le
  3547      abs_realpow_two
  3548      realpow_two_abs     
  3549 
  3550 * Theory Parity: added rules for simplifying exponents.
  3551 
  3552 * Theory List:
  3553 
  3554 The following theorems have been eliminated or modified
  3555 (INCOMPATIBILITY):
  3556 
  3557   list_all_Nil       now named list_all.simps(1)
  3558   list_all_Cons      now named list_all.simps(2)
  3559   list_all_conv      now named list_all_iff
  3560   set_mem_eq         now named mem_iff
  3561 
  3562 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3563 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3564 
  3565 
  3566 *** HOL-Complex ***
  3567 
  3568 * Theory RealDef: better support for embedding natural numbers and
  3569 integers in the reals.
  3570 
  3571 The following theorems have been eliminated or modified
  3572 (INCOMPATIBILITY):
  3573 
  3574   exp_ge_add_one_self  now requires no hypotheses
  3575   real_of_int_add      reversed direction of equality (use [symmetric])
  3576   real_of_int_minus    reversed direction of equality (use [symmetric])
  3577   real_of_int_diff     reversed direction of equality (use [symmetric])
  3578   real_of_int_mult     reversed direction of equality (use [symmetric])
  3579 
  3580 * Theory RComplete: expanded support for floor and ceiling functions.
  3581 
  3582 * Theory Ln is new, with properties of the natural logarithm
  3583 
  3584 * Hyperreal: There is a new type constructor "star" for making
  3585 nonstandard types.  The old type names are now type synonyms:
  3586 
  3587   hypreal = real star
  3588   hypnat = nat star
  3589   hcomplex = complex star
  3590 
  3591 * Hyperreal: Many groups of similarly-defined constants have been
  3592 replaced by polymorphic versions (INCOMPATIBILITY):
  3593 
  3594   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3595 
  3596   starset      <-- starsetNat, starsetC
  3597   *s*          <-- *sNat*, *sc*
  3598   starset_n    <-- starsetNat_n, starsetC_n
  3599   *sn*         <-- *sNatn*, *scn*
  3600   InternalSets <-- InternalNatSets, InternalCSets
  3601 
  3602   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3603   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3604   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3605   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3606   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3607 
  3608 * Hyperreal: Many type-specific theorems have been removed in favor of
  3609 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3610 
  3611   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3612   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3613   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3614   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3615   right_minus <-- hypreal_add_minus
  3616   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3617   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3618   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3619   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3620   mult_1_right <-- hcomplex_mult_one_right
  3621   mult_zero_left <-- hcomplex_mult_zero_left
  3622   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3623   right_distrib <-- hypnat_add_mult_distrib2
  3624   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3625   right_inverse <-- hypreal_mult_inverse
  3626   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3627   order_refl <-- {hypreal,hypnat}_le_refl
  3628   order_trans <-- {hypreal,hypnat}_le_trans
  3629   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3630   order_less_le <-- {hypreal,hypnat}_less_le
  3631   linorder_linear <-- {hypreal,hypnat}_le_linear
  3632   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3633   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3634   add_nonneg_nonneg <-- hypreal_le_add_order
  3635 
  3636 * Hyperreal: Separate theorems having to do with type-specific
  3637 versions of constants have been merged into theorems that apply to the
  3638 new polymorphic constants (INCOMPATIBILITY):
  3639 
  3640   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3641   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3642   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3643   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3644   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3645   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3646   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3647   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3648   STAR_diff <-- {STAR,STARC}_diff
  3649   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3650     STARC_hcomplex_of_complex}_image_subset
  3651   starset_n_Un <-- starset{Nat,C}_n_Un
  3652   starset_n_Int <-- starset{Nat,C}_n_Int
  3653   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3654   starset_n_diff <-- starset{Nat,C}_n_diff
  3655   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3656   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3657   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3658   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3659   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3660   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3661   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3662   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3663   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3664   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3665   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3666   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3667   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3668   starfun_diff <-- starfun{C,RC,CR}_diff
  3669   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3670   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3671   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3672   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3673   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3674   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3675   starfun_Id <-- starfunC_Id
  3676   starfun_approx <-- starfun{Nat,CR}_approx
  3677   starfun_capprox <-- starfun{C,RC}_capprox
  3678   starfun_abs <-- starfunNat_rabs
  3679   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3680   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3681   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3682   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3683   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3684   starfun_add_approx <-- starfunCR_add_approx
  3685   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3686   starfun_divide <-- starfun{C,CR,RC}_divide
  3687   starfun_n <-- starfun{Nat,C}_n
  3688   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3689   starfun_n_add <-- starfun{Nat,C}_n_add
  3690   starfun_n_add_minus <-- starfunNat_n_add_minus
  3691   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3692   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3693   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3694 
  3695   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3696   star_n_minus <-- {hypreal,hcomplex}_minus
  3697   star_n_diff <-- {hypreal,hcomplex}_diff
  3698   star_n_mult <-- {hypreal,hcomplex}_mult
  3699   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3700   star_n_le <-- {hypreal,hypnat}_le
  3701   star_n_less <-- {hypreal,hypnat}_less
  3702   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3703   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3704   star_n_abs <-- hypreal_hrabs
  3705   star_n_divide <-- hcomplex_divide
  3706 
  3707   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3708   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3709   star_of_diff <-- hypreal_of_real_diff
  3710   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3711   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3712   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3713   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3714   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3715   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3716   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3717   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3718   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3719   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3720   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3721   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3722   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3723   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3724   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3725   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3726   star_of_power <-- hypreal_of_real_power
  3727   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3728 
  3729 * Hyperreal: new method "transfer" that implements the transfer
  3730 principle of nonstandard analysis. With a subgoal that mentions
  3731 nonstandard types like "'a star", the command "apply transfer"
  3732 replaces it with an equivalent one that mentions only standard types.
  3733 To be successful, all free variables must have standard types; non-
  3734 standard variables must have explicit universal quantifiers.
  3735 
  3736 * Hyperreal: A theory of Taylor series.
  3737 
  3738 
  3739 *** HOLCF ***
  3740 
  3741 * Discontinued special version of 'constdefs' (which used to support
  3742 continuous functions) in favor of the general Pure one with full
  3743 type-inference.
  3744 
  3745 * New simplification procedure for solving continuity conditions; it
  3746 is much faster on terms with many nested lambda abstractions (cubic
  3747 instead of exponential time).
  3748 
  3749 * New syntax for domain package: selector names are now optional.
  3750 Parentheses should be omitted unless argument is lazy, for example:
  3751 
  3752   domain 'a stream = cons "'a" (lazy "'a stream")
  3753 
  3754 * New command 'fixrec' for defining recursive functions with pattern
  3755 matching; defining multiple functions with mutual recursion is also
  3756 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3757 sinr, or any data constructor defined by the domain package. The given
  3758 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3759 syntax and examples.
  3760 
  3761 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3762 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3763 but the proof obligation additionally includes an admissibility
  3764 requirement. The packages generate instances of class cpo or pcpo,
  3765 with continuity and strictness theorems for Rep and Abs.
  3766 
  3767 * HOLCF: Many theorems have been renamed according to a more standard naming
  3768 scheme (INCOMPATIBILITY):
  3769 
  3770   foo_inject:  "foo$x = foo$y ==> x = y"
  3771   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3772   foo_less:    "(foo$x << foo$y) = (x << y)"
  3773   foo_strict:  "foo$UU = UU"
  3774   foo_defined: "... ==> foo$x ~= UU"
  3775   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3776 
  3777 
  3778 *** ZF ***
  3779 
  3780 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3781 including the First Isomorphism Theorem (on quotienting by the kernel
  3782 of a homomorphism).
  3783 
  3784 * ZF/Simplifier: install second copy of type solver that actually
  3785 makes use of TC rules declared to Isar proof contexts (or locales);
  3786 the old version is still required for ML proof scripts.
  3787 
  3788 
  3789 *** Cube ***
  3790 
  3791 * Converted to Isar theory format; use locales instead of axiomatic
  3792 theories.
  3793 
  3794 
  3795 *** ML ***
  3796 
  3797 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3798 for ||>, ||>>, |>>,
  3799 
  3800 * Pure/library.ML no longer defines its own option datatype, but uses
  3801 that of the SML basis, which has constructors NONE and SOME instead of
  3802 None and Some, as well as exception Option.Option instead of OPTION.
  3803 The functions the, if_none, is_some, is_none have been adapted
  3804 accordingly, while Option.map replaces apsome.
  3805 
  3806 * Pure/library.ML: the exception LIST has been given up in favour of
  3807 the standard exceptions Empty and Subscript, as well as
  3808 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3809 superceded by the standard hd and tl functions etc.
  3810 
  3811 A number of basic list functions are no longer exported to the ML
  3812 toplevel, as they are variants of predefined functions.  The following
  3813 suggests how one can translate existing code:
  3814 
  3815     rev_append xs ys = List.revAppend (xs, ys)
  3816     nth_elem (i, xs) = List.nth (xs, i)
  3817     last_elem xs = List.last xs
  3818     flat xss = List.concat xss
  3819     seq fs = List.app fs
  3820     partition P xs = List.partition P xs
  3821     mapfilter f xs = List.mapPartial f xs
  3822 
  3823 * Pure/library.ML: several combinators for linear functional
  3824 transformations, notably reverse application and composition:
  3825 
  3826   x |> f                f #> g
  3827   (x, y) |-> f          f #-> g
  3828 
  3829 * Pure/library.ML: introduced/changed precedence of infix operators:
  3830 
  3831   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3832   infix 2 ?;
  3833   infix 3 o oo ooo oooo;
  3834   infix 4 ~~ upto downto;
  3835 
  3836 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3837 infix operators.
  3838 
  3839 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3840 fold_map support linear functional transformations and nesting.  For
  3841 example:
  3842 
  3843   fold f [x1, ..., xN] y =
  3844     y |> f x1 |> ... |> f xN
  3845 
  3846   (fold o fold) f [xs1, ..., xsN] y =
  3847     y |> fold f xs1 |> ... |> fold f xsN
  3848 
  3849   fold f [x1, ..., xN] =
  3850     f x1 #> ... #> f xN
  3851 
  3852   (fold o fold) f [xs1, ..., xsN] =
  3853     fold f xs1 #> ... #> fold f xsN
  3854 
  3855 * Pure/library.ML: the following selectors on type 'a option are
  3856 available:
  3857 
  3858   the:               'a option -> 'a  (*partial*)
  3859   these:             'a option -> 'a  where 'a = 'b list
  3860   the_default: 'a -> 'a option -> 'a
  3861   the_list:          'a option -> 'a list
  3862 
  3863 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3864 basic operations for association lists, following natural argument
  3865 order; moreover the explicit equality predicate passed here avoids
  3866 potentially expensive polymorphic runtime equality checks.
  3867 The old functions may be expressed as follows:
  3868 
  3869   assoc = uncurry (AList.lookup (op =))
  3870   assocs = these oo AList.lookup (op =)
  3871   overwrite = uncurry (AList.update (op =)) o swap
  3872 
  3873 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3874 
  3875   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3876   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3877 
  3878 replacing make_keylist and keyfilter (occassionally used)
  3879 Naive rewrites:
  3880 
  3881   make_keylist = AList.make
  3882   keyfilter = AList.find (op =)
  3883 
  3884 * eq_fst and eq_snd now take explicit equality parameter, thus
  3885   avoiding eqtypes. Naive rewrites:
  3886 
  3887     eq_fst = eq_fst (op =)
  3888     eq_snd = eq_snd (op =)
  3889 
  3890 * Removed deprecated apl and apr (rarely used).
  3891   Naive rewrites:
  3892 
  3893     apl (n, op) =>>= curry op n
  3894     apr (op, m) =>>= fn n => op (n, m)
  3895 
  3896 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3897 provides a reasonably efficient light-weight implementation of sets as
  3898 lists.
  3899 
  3900 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3901 few new operations; existing lookup and update are now curried to
  3902 follow natural argument order (for use with fold etc.);
  3903 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3904 
  3905 * Pure/General: output via the Isabelle channels of
  3906 writeln/warning/error etc. is now passed through Output.output, with a
  3907 hook for arbitrary transformations depending on the print_mode
  3908 (cf. Output.add_mode -- the first active mode that provides a output
  3909 function wins).  Already formatted output may be embedded into further
  3910 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3911 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3912 accommodate easy composition of diagnostic messages etc.  Programmers
  3913 rarely need to care about Output.output or Output.raw at all, with
  3914 some notable exceptions: Output.output is required when bypassing the
  3915 standard channels (writeln etc.), or in token translations to produce
  3916 properly formatted results; Output.raw is required when capturing
  3917 already output material that will eventually be presented to the user
  3918 a second time.  For the default print mode, both Output.output and
  3919 Output.raw have no effect.
  3920 
  3921 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3922 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3923 cumulative results are displayed at the end of a batch session.
  3924 
  3925 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3926 replaced by File.platform_path and File.shell_path (with appropriate
  3927 hooks).  This provides a clean interface for unusual systems where the
  3928 internal and external process view of file names are different.
  3929 
  3930 * Pure: more efficient orders for basic syntactic entities: added
  3931 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3932 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3933 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3934 orders now -- potential INCOMPATIBILITY for code that depends on a
  3935 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3936 Library.sort_strings on result).
  3937 
  3938 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3939 fold_types traverse types/terms from left to right, observing natural
  3940 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3941 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3942 
  3943 * Pure: name spaces have been refined, with significant changes of the
  3944 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3945 to extern(_table).  The plain name entry path is superceded by a
  3946 general 'naming' context, which also includes the 'policy' to produce
  3947 a fully qualified name and external accesses of a fully qualified
  3948 name; NameSpace.extend is superceded by context dependent
  3949 Sign.declare_name.  Several theory and proof context operations modify
  3950 the naming context.  Especially note Theory.restore_naming and
  3951 ProofContext.restore_naming to get back to a sane state; note that
  3952 Theory.add_path is no longer sufficient to recover from
  3953 Theory.absolute_path in particular.
  3954 
  3955 * Pure: new flags short_names (default false) and unique_names
  3956 (default true) for controlling output of qualified names.  If
  3957 short_names is set, names are printed unqualified.  If unique_names is
  3958 reset, the name prefix is reduced to the minimum required to achieve
  3959 the original result when interning again, even if there is an overlap
  3960 with earlier declarations.
  3961 
  3962 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3963 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3964 (useful for printing error messages).  INCOMPATIBILITY.
  3965 
  3966 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3967 Theory.theory are now identified, referring to the universal
  3968 Context.theory (see Pure/context.ML).  Actual signature and theory
  3969 content is managed as theory data.  The old code and interfaces were
  3970 spread over many files and structures; the new arrangement introduces
  3971 considerable INCOMPATIBILITY to gain more clarity:
  3972 
  3973   Context -- theory management operations (name, identity, inclusion,
  3974     parents, ancestors, merge, etc.), plus generic theory data;
  3975 
  3976   Sign -- logical signature and syntax operations (declaring consts,
  3977     types, etc.), plus certify/read for common entities;
  3978 
  3979   Theory -- logical theory operations (stating axioms, definitions,
  3980     oracles), plus a copy of logical signature operations (consts,
  3981     types, etc.); also a few basic management operations (Theory.copy,
  3982     Theory.merge, etc.)
  3983 
  3984 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3985 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3986 for convenience -- they merely return the theory.
  3987 
  3988 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3989 
  3990 * Pure: the Isar proof context type is already defined early in Pure
  3991 as Context.proof (note that ProofContext.context and Proof.context are
  3992 aliases, where the latter is the preferred name).  This enables other
  3993 Isabelle components to refer to that type even before Isar is present.
  3994 
  3995 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  3996 typeK, constK, axiomK, oracleK), but provide explicit operations for
  3997 any of these kinds.  For example, Sign.intern typeK is now
  3998 Sign.intern_type, Theory.hide_space Sign.typeK is now
  3999 Theory.hide_types.  Also note that former
  4000 Theory.hide_classes/types/consts are now
  4001 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4002 internalize their arguments!  INCOMPATIBILITY.
  4003 
  4004 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4005 datatype thmref (with constructors Name and NameSelection) instead of
  4006 plain string -- INCOMPATIBILITY;
  4007 
  4008 * Pure: cases produced by proof methods specify options, where NONE
  4009 means to remove case bindings -- INCOMPATIBILITY in
  4010 (RAW_)METHOD_CASES.
  4011 
  4012 * Pure: the following operations retrieve axioms or theorems from a
  4013 theory node or theory hierarchy, respectively:
  4014 
  4015   Theory.axioms_of: theory -> (string * term) list
  4016   Theory.all_axioms_of: theory -> (string * term) list
  4017   PureThy.thms_of: theory -> (string * thm) list
  4018   PureThy.all_thms_of: theory -> (string * thm) list
  4019 
  4020 * Pure: print_tac now outputs the goal through the trace channel.
  4021 
  4022 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4023 Reference Toplevel.debug (default false) controls detailed printing
  4024 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4025 controls execution profiling -- set to 1 for time and 2 for space
  4026 (both increase the runtime).
  4027 
  4028 * Isar session: The initial use of ROOT.ML is now always timed,
  4029 i.e. the log will show the actual process times, in contrast to the
  4030 elapsed wall-clock time that the outer shell wrapper produces.
  4031 
  4032 * Simplifier: improved handling of bound variables (nameless
  4033 representation, avoid allocating new strings).  Simprocs that invoke
  4034 the Simplifier recursively should use Simplifier.inherit_bounds to
  4035 avoid local name clashes.  Failure to do so produces warnings
  4036 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4037 for further details.
  4038 
  4039 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4040 bindings for all theorems stored within a given theory; this may help
  4041 in porting non-Isar theories to Isar ones, while keeping ML proof
  4042 scripts for the time being.
  4043 
  4044 * ML operator HTML.with_charset specifies the charset begin used for
  4045 generated HTML files.  For example:
  4046 
  4047   HTML.with_charset "utf-8" use_thy "Hebrew";
  4048   HTML.with_charset "utf-8" use_thy "Chinese";
  4049 
  4050 
  4051 *** System ***
  4052 
  4053 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4054 isabelle, isatool etc.).
  4055 
  4056 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4057 isatool doc, isatool mkdir, display_drafts etc.).
  4058 
  4059 * isatool usedir: option -f allows specification of the ML file to be
  4060 used by Isabelle; default is ROOT.ML.
  4061 
  4062 * New isatool version outputs the version identifier of the Isabelle
  4063 distribution being used.
  4064 
  4065 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4066 (containing Boolean satisfiability problems) into Isabelle/HOL
  4067 theories.
  4068 
  4069 
  4070 
  4071 New in Isabelle2004 (April 2004)
  4072 --------------------------------
  4073 
  4074 *** General ***
  4075 
  4076 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4077   Replaces linorder.ML.
  4078 
  4079 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4080   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4081   (\<a>...\<z>), are now considered normal letters, and can therefore
  4082   be used anywhere where an ASCII letter (a...zA...Z) has until
  4083   now. COMPATIBILITY: This obviously changes the parsing of some
  4084   terms, especially where a symbol has been used as a binder, say
  4085   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4086   as an identifier.  Fix it by inserting a space around former
  4087   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4088   existing theory and ML files.
  4089 
  4090 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4091 
  4092 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4093   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4094   a normal (but invisible) letter. For multiple letter subscripts repeat
  4095   \<^isub> like this: x\<^isub>1\<^isub>2.
  4096 
  4097 * Pure: There are now sub-/superscripts that can span more than one
  4098   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4099   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4100   superscript. The new control characters are not identifier parts.
  4101 
  4102 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4103   content of "..." to the latex file instead of \isacntrl... . The "..."
  4104   may consist of any printable characters excluding the end bracket >.
  4105 
  4106 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4107   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4108   declare constants "final", which prevents their being given a definition
  4109   later.  It is useful for constants whose behaviour is fixed axiomatically
  4110   rather than definitionally, such as the meta-logic connectives.
  4111 
  4112 * Pure: 'instance' now handles general arities with general sorts
  4113   (i.e. intersections of classes),
  4114 
  4115 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4116   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4117   It can be changed to alter the colors/layout of generated pages.
  4118 
  4119 
  4120 *** Isar ***
  4121 
  4122 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4123   cut_tac, subgoal_tac and thin_tac:
  4124   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4125     locales are no longer forced to write Isar proof scripts.
  4126     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4127     emulations.
  4128   - INCOMPATIBILITY: names of variables to be instantiated may no
  4129     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4130     This is consistent with the instantiation attribute "where".
  4131 
  4132 * Attributes "where" and "of":
  4133   - Now take type variables of instantiated theorem into account when reading
  4134     the instantiation string.  This fixes a bug that caused instantiated
  4135     theorems to have too special types in some circumstances.
  4136   - "where" permits explicit instantiations of type variables.
  4137 
  4138 * Calculation commands "moreover" and "also" no longer interfere with
  4139   current facts ("this"), admitting arbitrary combinations with "then"
  4140   and derived forms.
  4141 
  4142 * Locales:
  4143   - Goal statements involving the context element "includes" no longer
  4144     generate theorems with internal delta predicates (those ending on
  4145     "_axioms") in the premise.
  4146     Resolve particular premise with <locale>.intro to obtain old form.
  4147   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4148     specification and "includes" elements in goal statement.
  4149   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4150     [intro?] and [elim?] (respectively) by default.
  4151   - Experimental command for instantiation of locales in proof contexts:
  4152         instantiate <label>[<attrs>]: <loc>
  4153     Instantiates locale <loc> and adds all its theorems to the current context
  4154     taking into account their attributes.  Label and attrs are optional
  4155     modifiers, like in theorem declarations.  If present, names of
  4156     instantiated theorems are qualified with <label>, and the attributes
  4157     <attrs> are applied after any attributes these theorems might have already.
  4158       If the locale has assumptions, a chained fact of the form
  4159     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4160     are derived.  The command does not support old-style locales declared
  4161     with "locale (open)".
  4162       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4163 
  4164 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4165   (Isar) contexts.
  4166 
  4167 
  4168 *** HOL ***
  4169 
  4170 * Proof import: new image HOL4 contains the imported library from
  4171   the HOL4 system with about 2500 theorems. It is imported by
  4172   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4173   can be used like any other Isabelle image.  See
  4174   HOL/Import/HOL/README for more information.
  4175 
  4176 * Simplifier:
  4177   - Much improved handling of linear and partial orders.
  4178     Reasoners for linear and partial orders are set up for type classes
  4179     "linorder" and "order" respectively, and are added to the default simpset
  4180     as solvers.  This means that the simplifier can build transitivity chains
  4181     to solve goals from the assumptions.
  4182   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4183     of blast or auto after simplification become unnecessary because the goal
  4184     is solved by simplification already.
  4185 
  4186 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4187     all proved in axiomatic type classes for semirings, rings and fields.
  4188 
  4189 * Numerics:
  4190   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4191     now formalized using the Ring_and_Field theory mentioned above.
  4192   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4193     than before, because now they are set up once in a generic manner.
  4194   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4195     Look for the general versions in Ring_and_Field (and Power if they concern
  4196     exponentiation).
  4197 
  4198 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4199 
  4200 * Records:
  4201   - Record types are now by default printed with their type abbreviation
  4202     instead of the list of all field types. This can be configured via
  4203     the reference "print_record_type_abbr".
  4204   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4205     (not enabled by default).
  4206   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4207     EX x. x = sel r to True (not enabled by default).
  4208   - Tactic "record_split_simp_tac" to split and simplify records added.
  4209 
  4210 * 'specification' command added, allowing for definition by
  4211   specification.  There is also an 'ax_specification' command that
  4212   introduces the new constants axiomatically.
  4213 
  4214 * arith(_tac) is now able to generate counterexamples for reals as well.
  4215 
  4216 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4217 
  4218 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4219   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4220 
  4221 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4222   matrix theory to linear programming.
  4223 
  4224 * Unions and Intersections:
  4225   The latex output syntax of UN and INT has been changed
  4226   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4227   i.e. the index formulae has become a subscript.
  4228   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4229 
  4230 * Unions and Intersections over Intervals:
  4231   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4232   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4233   like in normal math, and corresponding versions for < and for intersection.
  4234 
  4235 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4236   lexicographic dictonary ordering has been added as "lexord".
  4237 
  4238 * ML: the legacy theory structures Int and List have been removed. They had
  4239   conflicted with ML Basis Library structures having the same names.
  4240 
  4241 * 'refute' command added to search for (finite) countermodels.  Only works
  4242   for a fragment of HOL.  The installation of an external SAT solver is
  4243   highly recommended.  See "HOL/Refute.thy" for details.
  4244 
  4245 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4246   formulae under an assignment of free variables to random values.
  4247   In contrast to 'refute', it can deal with inductive datatypes,
  4248   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4249   for examples.
  4250 
  4251 
  4252 *** HOLCF ***
  4253 
  4254 * Streams now come with concatenation and are part of the HOLCF image
  4255 
  4256 
  4257 
  4258 New in Isabelle2003 (May 2003)
  4259 ------------------------------
  4260 
  4261 *** General ***
  4262 
  4263 * Provers/simplifier:
  4264 
  4265   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4266     Assumptions are now subject to complete mutual simplification,
  4267     not just from left to right. The simplifier now preserves
  4268     the order of assumptions.
  4269 
  4270     Potential INCOMPATIBILITY:
  4271 
  4272     -- simp sometimes diverges where the old version did
  4273        not, e.g. invoking simp on the goal
  4274 
  4275         [| P (f x); y = x; f x = f y |] ==> Q
  4276 
  4277        now gives rise to the infinite reduction sequence
  4278 
  4279         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4280 
  4281        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4282        kind of problem.
  4283 
  4284     -- Tactics combining classical reasoner and simplification (such as auto)
  4285        are also affected by this change, because many of them rely on
  4286        simp. They may sometimes diverge as well or yield a different numbers
  4287        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4288        in case of problems. Sometimes subsequent calls to the classical
  4289        reasoner will fail because a preceeding call to the simplifier too
  4290        eagerly simplified the goal, e.g. deleted redundant premises.
  4291 
  4292   - The simplifier trace now shows the names of the applied rewrite rules
  4293 
  4294   - You can limit the number of recursive invocations of the simplifier
  4295     during conditional rewriting (where the simplifie tries to solve the
  4296     conditions before applying the rewrite rule):
  4297     ML "simp_depth_limit := n"
  4298     where n is an integer. Thus you can force termination where previously
  4299     the simplifier would diverge.
  4300 
  4301   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4302 
  4303   - No longer aborts on failed congruence proof.  Instead, the
  4304     congruence is ignored.
  4305 
  4306 * Pure: New generic framework for extracting programs from constructive
  4307   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4308   as HOL/Extraction for some case studies.
  4309 
  4310 * Pure: The main goal of the proof state is no longer shown by default, only
  4311 the subgoals. This behaviour is controlled by a new flag.
  4312    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4313 (ML: Proof.show_main_goal).
  4314 
  4315 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4316 rules whose conclusion matches subgoal 1:
  4317       PG menu: Isabelle/Isar -> Show me -> matching rules
  4318 The rules are ordered by how closely they match the subgoal.
  4319 In particular, rules that solve a subgoal outright are displayed first
  4320 (or rather last, the way they are printed).
  4321 (ML: ProofGeneral.print_intros())
  4322 
  4323 * Pure: New flag trace_unify_fail causes unification to print
  4324 diagnostic information (PG: in trace buffer) when it fails. This is
  4325 useful for figuring out why single step proofs like rule, erule or
  4326 assumption failed.
  4327 
  4328 * Pure: Locale specifications now produce predicate definitions
  4329 according to the body of text (covering assumptions modulo local
  4330 definitions); predicate "loc_axioms" covers newly introduced text,
  4331 while "loc" is cumulative wrt. all included locale expressions; the
  4332 latter view is presented only on export into the global theory
  4333 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4334 on the old view without predicates;
  4335 
  4336 * Pure: predefined locales "var" and "struct" are useful for sharing
  4337 parameters (as in CASL, for example); just specify something like
  4338 ``var x + var y + struct M'' as import;
  4339 
  4340 * Pure: improved thms_containing: proper indexing of facts instead of
  4341 raw theorems; check validity of results wrt. current name space;
  4342 include local facts of proof configuration (also covers active
  4343 locales), cover fixed variables in index; may use "_" in term
  4344 specification; an optional limit for the number of printed facts may
  4345 be given (the default is 40);
  4346 
  4347 * Pure: disallow duplicate fact bindings within new-style theory files
  4348 (batch-mode only);
  4349 
  4350 * Provers: improved induct method: assumptions introduced by case
  4351 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4352 the goal statement); "foo" still refers to all facts collectively;
  4353 
  4354 * Provers: the function blast.overloaded has been removed: all constants
  4355 are regarded as potentially overloaded, which improves robustness in exchange
  4356 for slight decrease in efficiency;
  4357 
  4358 * Provers/linorder: New generic prover for transitivity reasoning over
  4359 linear orders.  Note: this prover is not efficient!
  4360 
  4361 * Isar: preview of problems to finish 'show' now produce an error
  4362 rather than just a warning (in interactive mode);
  4363 
  4364 
  4365 *** HOL ***
  4366 
  4367 * arith(_tac)
  4368 
  4369  - Produces a counter example if it cannot prove a goal.
  4370    Note that the counter example may be spurious if the goal is not a formula
  4371    of quantifier-free linear arithmetic.
  4372    In ProofGeneral the counter example appears in the trace buffer.
  4373 
  4374  - Knows about div k and mod k where k is a numeral of type nat or int.
  4375 
  4376  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4377    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4378    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4379 
  4380 * simp's arithmetic capabilities have been enhanced a bit: it now
  4381 takes ~= in premises into account (by performing a case split);
  4382 
  4383 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4384 are distributed over a sum of terms;
  4385 
  4386 * New tactic "trans_tac" and method "trans" instantiate
  4387 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4388 "<=", "<" and "=").
  4389 
  4390 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4391 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4392 
  4393 * 'typedef' command has new option "open" to suppress the set
  4394 definition;
  4395 
  4396 * functions Min and Max on finite sets have been introduced (theory
  4397 Finite_Set);
  4398 
  4399 * attribute [symmetric] now works for relations as well; it turns
  4400 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4401 
  4402 * induct over a !!-quantified statement (say !!x1..xn):
  4403   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4404 
  4405 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4406 %x. None. Warning: empty_def now refers to the previously hidden definition
  4407 of the empty set.
  4408 
  4409 * Algebra: formalization of classical algebra.  Intended as base for
  4410 any algebraic development in Isabelle.  Currently covers group theory
  4411 (up to Sylow's theorem) and ring theory (Universal Property of
  4412 Univariate Polynomials).  Contributions welcome;
  4413 
  4414 * GroupTheory: deleted, since its material has been moved to Algebra;
  4415 
  4416 * Complex: new directory of the complex numbers with numeric constants,
  4417 nonstandard complex numbers, and some complex analysis, standard and
  4418 nonstandard (Jacques Fleuriot);
  4419 
  4420 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4421 
  4422 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4423 Fleuriot);
  4424 
  4425 * Real/HahnBanach: updated and adapted to locales;
  4426 
  4427 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4428 Gray and Kramer);
  4429 
  4430 * UNITY: added the Meier-Sanders theory of progress sets;
  4431 
  4432 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4433 as abstract algorithms, instantiated to the JVM;
  4434 
  4435 * Bali: Java source language formalization. Type system, operational
  4436 semantics, axiomatic semantics. Supported language features:
  4437 classes, interfaces, objects,virtual methods, static methods,
  4438 static/instance fields, arrays, access modifiers, definite
  4439 assignment, exceptions.
  4440 
  4441 
  4442 *** ZF ***
  4443 
  4444 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4445 universe, etc.);
  4446 
  4447 * Main ZF: virtually all theories converted to new-style format;
  4448 
  4449 
  4450 *** ML ***
  4451 
  4452 * Pure: Tactic.prove provides sane interface for internal proofs;
  4453 omits the infamous "standard" operation, so this is more appropriate
  4454 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4455 
  4456 * Pure: improved error reporting of simprocs;
  4457 
  4458 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4459 up simprocs;
  4460 
  4461 
  4462 *** Document preparation ***
  4463 
  4464 * uses \par instead of \\ for line breaks in theory text. This may
  4465 shift some page breaks in large documents. To get the old behaviour
  4466 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4467 
  4468 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4469 other packages
  4470 
  4471 * \<euro> now needs package babel/greek instead of marvosym (which
  4472 broke \Rightarrow)
  4473 
  4474 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4475 textcomp package)
  4476 
  4477 
  4478 
  4479 New in Isabelle2002 (March 2002)
  4480 --------------------------------
  4481 
  4482 *** Document preparation ***
  4483 
  4484 * greatly simplified document preparation setup, including more
  4485 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4486 instructive isatool mkdir; users should basically be able to get
  4487 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4488 users may run a separate document processing stage manually like this:
  4489 "isatool usedir -D output HOL Test && isatool document Test/output";
  4490 
  4491 * theory dependency graph may now be incorporated into documents;
  4492 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4493 with \includegraphics of LaTeX;
  4494 
  4495 * proper spacing of consecutive markup elements, especially text
  4496 blocks after section headings;
  4497 
  4498 * support bold style (for single symbols only), input syntax is like
  4499 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4500 
  4501 * \<bullet> is now output as bold \cdot by default, which looks much
  4502 better in printed text;
  4503 
  4504 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4505 note that these symbols are currently unavailable in Proof General /
  4506 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4507 
  4508 * isatool latex no longer depends on changed TEXINPUTS, instead
  4509 isatool document copies the Isabelle style files to the target
  4510 location;
  4511 
  4512 
  4513 *** Isar ***
  4514 
  4515 * Pure/Provers: improved proof by cases and induction;
  4516   - 'case' command admits impromptu naming of parameters (such as
  4517     "case (Suc n)");
  4518   - 'induct' method divinates rule instantiation from the inductive
  4519     claim; no longer requires excessive ?P bindings for proper
  4520     instantiation of cases;
  4521   - 'induct' method properly enumerates all possibilities of set/type
  4522     rules; as a consequence facts may be also passed through *type*
  4523     rules without further ado;
  4524   - 'induct' method now derives symbolic cases from the *rulified*
  4525     rule (before it used to rulify cases stemming from the internal
  4526     atomized version); this means that the context of a non-atomic
  4527     statement becomes is included in the hypothesis, avoiding the
  4528     slightly cumbersome show "PROP ?case" form;
  4529   - 'induct' may now use elim-style induction rules without chaining
  4530     facts, using ``missing'' premises from the goal state; this allows
  4531     rules stemming from inductive sets to be applied in unstructured
  4532     scripts, while still benefitting from proper handling of non-atomic
  4533     statements; NB: major inductive premises need to be put first, all
  4534     the rest of the goal is passed through the induction;
  4535   - 'induct' proper support for mutual induction involving non-atomic
  4536     rule statements (uses the new concept of simultaneous goals, see
  4537     below);
  4538   - append all possible rule selections, but only use the first
  4539     success (no backtracking);
  4540   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4541   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4542   - added 'print_induct_rules' (covered by help item in recent Proof
  4543     General versions);
  4544   - moved induct/cases attributes to Pure, methods to Provers;
  4545   - generic method setup instantiated for FOL and HOL;
  4546 
  4547 * Pure: support multiple simultaneous goal statements, for example
  4548 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4549 meta-level mechanism, this acts as if several individual goals had
  4550 been stated separately; in particular common proof methods need to be
  4551 repeated in order to cover all claims; note that a single elimination
  4552 step is *not* sufficient to establish the two conjunctions, so this
  4553 fails:
  4554 
  4555   assume "A & B" then have A and B ..   (*".." fails*)
  4556 
  4557 better use "obtain" in situations as above; alternative refer to
  4558 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4559 
  4560 * Pure: proper integration with ``locales''; unlike the original
  4561 version by Florian Kammller, Isar locales package high-level proof
  4562 contexts rather than raw logical ones (e.g. we admit to include
  4563 attributes everywhere); operations on locales include merge and
  4564 rename; support for implicit arguments (``structures''); simultaneous
  4565 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4566 some examples;
  4567 
  4568 * Pure: the following commands have been ``localized'', supporting a
  4569 target locale specification "(in name)": 'lemma', 'theorem',
  4570 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4571 stored both within the locale and at the theory level (exported and
  4572 qualified by the locale name);
  4573 
  4574 * Pure: theory goals may now be specified in ``long'' form, with
  4575 ad-hoc contexts consisting of arbitrary locale elements. for example
  4576 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4577 definitions may be given, too); the result is a meta-level rule with
  4578 the context elements being discharged in the obvious way;
  4579 
  4580 * Pure: new proof command 'using' allows to augment currently used
  4581 facts after a goal statement ('using' is syntactically analogous to
  4582 'apply', but acts on the goal's facts only); this allows chained facts
  4583 to be separated into parts given before and after a claim, as in
  4584 ``from a and b have C using d and e <proof>'';
  4585 
  4586 * Pure: renamed "antecedent" case to "rule_context";
  4587 
  4588 * Pure: new 'judgment' command records explicit information about the
  4589 object-logic embedding (used by several tools internally); no longer
  4590 use hard-wired "Trueprop";
  4591 
  4592 * Pure: added 'corollary' command;
  4593 
  4594 * Pure: fixed 'token_translation' command;
  4595 
  4596 * Pure: removed obsolete 'exported' attribute;
  4597 
  4598 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4599 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4600 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4601 
  4602 * Pure: method 'atomize' presents local goal premises as object-level
  4603 statements (atomic meta-level propositions); setup controlled via
  4604 rewrite rules declarations of 'atomize' attribute; example
  4605 application: 'induct' method with proper rule statements in improper
  4606 proof *scripts*;
  4607 
  4608 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4609 now consider the syntactic context of assumptions, giving a better
  4610 chance to get type-inference of the arguments right (this is
  4611 especially important for locales);
  4612 
  4613 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4614 mode;
  4615 
  4616 * Pure/obtain: the formal conclusion "thesis", being marked as
  4617 ``internal'', may no longer be reference directly in the text;
  4618 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4619 situations;
  4620 
  4621 * Pure: generic 'sym' attribute which declares a rule both as pure
  4622 'elim?' and for the 'symmetric' operation;
  4623 
  4624 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4625 text; the fixed correlation with particular command syntax has been
  4626 discontinued;
  4627 
  4628 * Pure: new method 'rules' is particularly well-suited for proof
  4629 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4630 but often produces more compact proof terms with less detours;
  4631 
  4632 * Pure/Provers/classical: simplified integration with pure rule
  4633 attributes and methods; the classical "intro?/elim?/dest?"
  4634 declarations coincide with the pure ones; the "rule" method no longer
  4635 includes classically swapped intros; "intro" and "elim" methods no
  4636 longer pick rules from the context; also got rid of ML declarations
  4637 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4638 INCOMPATIBILITY;
  4639 
  4640 * Provers/classical: attribute 'swapped' produces classical inversions
  4641 of introduction rules;
  4642 
  4643 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4644 rules instead of full simplifier context; 'iff' attribute handles
  4645 conditional rules;
  4646 
  4647 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4648 
  4649 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4650 "(permissive)" option to recover old behavior;
  4651 
  4652 * HOL: 'inductive' no longer features separate (collective) attributes
  4653 for 'intros' (was found too confusing);
  4654 
  4655 * HOL: properly declared induction rules less_induct and
  4656 wf_induct_rule;
  4657 
  4658 
  4659 *** HOL ***
  4660 
  4661 * HOL: moved over to sane numeral syntax; the new policy is as
  4662 follows:
  4663 
  4664   - 0 and 1 are polymorphic constants, which are defined on any
  4665   numeric type (nat, int, real etc.);
  4666 
  4667   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4668   binary representation internally;
  4669 
  4670   - type nat has special constructor Suc, and generally prefers Suc 0
  4671   over 1::nat and Suc (Suc 0) over 2::nat;
  4672 
  4673 This change may cause significant problems of INCOMPATIBILITY; here
  4674 are some hints on converting existing sources:
  4675 
  4676   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4677   entities, so expressions involving "-" (unary or binary minus) need
  4678   to be spaced properly;
  4679 
  4680   - existing occurrences of "1" may need to be constraint "1::nat" or
  4681   even replaced by Suc 0; similar for old "2";
  4682 
  4683   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4684 
  4685   - remove all special provisions on numerals in proofs;
  4686 
  4687 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4688 representation (depends on bin_arith_simps in the default context);
  4689 
  4690 * HOL: symbolic syntax for x^2 (numeral 2);
  4691 
  4692 * HOL: the class of all HOL types is now called "type" rather than
  4693 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4694 in axclass/classes, instance/arities, and (usually rare) occurrences
  4695 in typings (of consts etc.); internally the class is called
  4696 "HOL.type", ML programs should refer to HOLogic.typeS;
  4697 
  4698 * HOL/record package improvements:
  4699   - new derived operations "fields" to build a partial record section,
  4700     "extend" to promote a fixed record to a record scheme, and
  4701     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4702     declared as simp by default;
  4703   - shared operations ("more", "fields", etc.) now need to be always
  4704     qualified) --- potential INCOMPATIBILITY;
  4705   - removed "make_scheme" operations (use "make" with "extend") --
  4706     INCOMPATIBILITY;
  4707   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4708   - provides cases/induct rules for use with corresponding Isar
  4709     methods (for concrete records, record schemes, concrete more
  4710     parts, and schematic more parts -- in that order);
  4711   - internal definitions directly based on a light-weight abstract
  4712     theory of product types over typedef rather than datatype;
  4713 
  4714 * HOL: generic code generator for generating executable ML code from
  4715 specifications; specific support for HOL constructs such as inductive
  4716 datatypes and sets, as well as recursive functions; can be invoked
  4717 via 'generate_code' theory section;
  4718 
  4719 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4720 
  4721 * HOL: consolidated and renamed several theories.  In particular:
  4722         Ord.thy has been absorbed into HOL.thy
  4723         String.thy has been absorbed into List.thy
  4724 
  4725 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4726 (beware of argument permutation!);
  4727 
  4728 * HOL: linorder_less_split superseded by linorder_cases;
  4729 
  4730 * HOL/List: "nodups" renamed to "distinct";
  4731 
  4732 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4733 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4734   - Ex_def has changed, now need to use some_eq_ex
  4735 
  4736 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4737 in this (rare) case use:
  4738 
  4739   delSWrapper "split_all_tac"
  4740   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4741 
  4742 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4743 MAY FAIL;
  4744 
  4745 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4746 Isabelle's type classes, ^ on functions and relations has too general
  4747 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4748 necessary to attach explicit type constraints;
  4749 
  4750 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4751 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4752 renamed accordingly (eg "compI" -> "rel_compI").
  4753 
  4754 * HOL: syntax translations now work properly with numerals and records
  4755 expressions;
  4756 
  4757 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4758 of "lam" -- INCOMPATIBILITY;
  4759 
  4760 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4761 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4762 renamed "Product_Type.unit";
  4763 
  4764 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4765 
  4766 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4767 the "cases" method);
  4768 
  4769 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4770 Florian Kammller);
  4771 
  4772 * HOL/IMP: updated and converted to new-style theory format; several
  4773 parts turned into readable document, with proper Isar proof texts and
  4774 some explanations (by Gerwin Klein);
  4775 
  4776 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4777 
  4778 * HOL-Hyperreal is now a logic image;
  4779 
  4780 
  4781 *** HOLCF ***
  4782 
  4783 * Isar: consts/constdefs supports mixfix syntax for continuous
  4784 operations;
  4785 
  4786 * Isar: domain package adapted to new-style theory format, e.g. see
  4787 HOLCF/ex/Dnat.thy;
  4788 
  4789 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4790 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4791 lift.induct_tac, always use UU instead of Undef;
  4792 
  4793 * HOLCF/IMP: updated and converted to new-style theory;
  4794 
  4795 
  4796 *** ZF ***
  4797 
  4798 * Isar: proper integration of logic-specific tools and packages,
  4799 including theory commands '(co)inductive', '(co)datatype',
  4800 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4801 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4802 
  4803 * theory Main no longer includes AC; for the Axiom of Choice, base
  4804 your theory on Main_ZFC;
  4805 
  4806 * the integer library now covers quotients and remainders, with many
  4807 laws relating division to addition, multiplication, etc.;
  4808 
  4809 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4810 typeless version of the formalism;
  4811 
  4812 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4813 format;
  4814 
  4815 * ZF/Induct: new directory for examples of inductive definitions,
  4816 including theory Multiset for multiset orderings; converted to
  4817 new-style theory format;
  4818 
  4819 * ZF: many new theorems about lists, ordinals, etc.;
  4820 
  4821 
  4822 *** General ***
  4823 
  4824 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4825 variable proof controls level of detail: 0 = no proofs (only oracle
  4826 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4827 also ref manual for further ML interfaces;
  4828 
  4829 * Pure/axclass: removed obsolete ML interface
  4830 goal_subclass/goal_arity;
  4831 
  4832 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4833 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4834 separate tokens, so expressions involving minus need to be spaced
  4835 properly;
  4836 
  4837 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4838 rather than "infixl" or "infixr";
  4839 
  4840 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4841 sort constraint specifications in type inference; e.g. "x::_::foo"
  4842 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4843 type variable);
  4844 
  4845 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4846 control output of nested => (types); the default behavior is
  4847 "type_brackets";
  4848 
  4849 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4850 tokens into AST constants;
  4851 
  4852 * Pure/syntax: prefer later declarations of translations and print
  4853 translation functions; potential INCOMPATIBILITY: need to reverse
  4854 multiple declarations for same syntax element constant;
  4855 
  4856 * Pure/show_hyps reset by default (in accordance to existing Isar
  4857 practice);
  4858 
  4859 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4860 addSafter;
  4861 
  4862 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4863 as well;
  4864 
  4865 * system: tested support for MacOS X; should be able to get Isabelle +
  4866 Proof General to work in a plain Terminal after installing Poly/ML
  4867 (e.g. from the Isabelle distribution area) and GNU bash alone
  4868 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4869 support requires further installations, e.g. from
  4870 http://fink.sourceforge.net/);
  4871 
  4872 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4873 
  4874 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4875 of 40 MB), cf. ML_OPTIONS;
  4876 
  4877 * system: Proof General keywords specification is now part of the
  4878 Isabelle distribution (see etc/isar-keywords.el);
  4879 
  4880 * system: support for persistent Proof General sessions (refrain from
  4881 outdating all loaded theories on startup); user may create writable
  4882 logic images like this: ``isabelle -q HOL Test'';
  4883 
  4884 * system: smart selection of Isabelle process versus Isabelle
  4885 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4886 run both "isabelle" and "Isabelle" even if file names are badly
  4887 damaged (executable inspects the case of the first letter of its own
  4888 name); added separate "isabelle-process" and "isabelle-interface";
  4889 
  4890 * system: refrain from any attempt at filtering input streams; no
  4891 longer support ``8bit'' encoding of old isabelle font, instead proper
  4892 iso-latin characters may now be used; the related isatools
  4893 "symbolinput" and "nonascii" have disappeared as well;
  4894 
  4895 * system: removed old "xterm" interface (the print modes "xterm" and
  4896 "xterm_color" are still available for direct use in a suitable
  4897 terminal);
  4898 
  4899 
  4900 
  4901 New in Isabelle99-2 (February 2001)
  4902 -----------------------------------
  4903 
  4904 *** Overview of INCOMPATIBILITIES ***
  4905 
  4906 * HOL: please note that theories in the Library and elsewhere often use the
  4907 new-style (Isar) format; to refer to their theorems in an ML script you must
  4908 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4909 
  4910 * HOL: inductive package no longer splits induction rule aggressively,
  4911 but only as far as specified by the introductions given; the old
  4912 format may be recovered via ML function complete_split_rule or attribute
  4913 'split_rule (complete)';
  4914 
  4915 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4916 gfp_Tarski to gfp_unfold;
  4917 
  4918 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4919 
  4920 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4921 relation); infix "^^" has been renamed "``"; infix "``" has been
  4922 renamed "`"; "univalent" has been renamed "single_valued";
  4923 
  4924 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4925 operation;
  4926 
  4927 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4928 
  4929 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4930 
  4931 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4932 consequence, it is no longer monotonic wrt. the local goal context
  4933 (which is now passed through the inductive cases);
  4934 
  4935 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4936 \<gg> to \<ggreater>;
  4937 
  4938 
  4939 *** Document preparation ***
  4940 
  4941 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4942 available: are "it" for near math-mode best-style output, "sl" for
  4943 slanted text style, and "tt" for plain type-writer; if no
  4944 \isabellestyle command is given, output is according to slanted
  4945 type-writer);
  4946 
  4947 * support sub/super scripts (for single symbols only), input syntax is
  4948 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4949 
  4950 * some more standard symbols; see Appendix A of the system manual for
  4951 the complete list of symbols defined in isabellesym.sty;
  4952 
  4953 * improved isabelle style files; more abstract symbol implementation
  4954 (should now use \isamath{...} and \isatext{...} in custom symbol
  4955 definitions);
  4956 
  4957 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4958 state; Note that presentation of goal states does not conform to
  4959 actual human-readable proof documents.  Please do not include goal
  4960 states into document output unless you really know what you are doing!
  4961 
  4962 * proper indentation of antiquoted output with proportional LaTeX
  4963 fonts;
  4964 
  4965 * no_document ML operator temporarily disables LaTeX document
  4966 generation;
  4967 
  4968 * isatool unsymbolize tunes sources for plain ASCII communication;
  4969 
  4970 
  4971 *** Isar ***
  4972 
  4973 * Pure: Isar now suffers initial goal statements to contain unbound
  4974 schematic variables (this does not conform to actual readable proof
  4975 documents, due to unpredictable outcome and non-compositional proof
  4976 checking); users who know what they are doing may use schematic goals
  4977 for Prolog-style synthesis of proven results;
  4978 
  4979 * Pure: assumption method (an implicit finishing) now handles actual
  4980 rules as well;
  4981 
  4982 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4983 initial goal, declare "that" only as Pure intro (only for single
  4984 steps); the "that" rule assumption may now be involved in implicit
  4985 finishing, thus ".." becomes a feasible for trivial obtains;
  4986 
  4987 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4988 instance proofs may be performed by "..";
  4989 
  4990 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  4991 statements as well;
  4992 
  4993 * Pure: more robust selection of calculational rules;
  4994 
  4995 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  4996 rule (as well as the assumption rule);
  4997 
  4998 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  4999 lemmas, using the graph browser tool;
  5000 
  5001 * Pure: predict failure of "show" in interactive mode;
  5002 
  5003 * Pure: 'thms_containing' now takes actual terms as arguments;
  5004 
  5005 * HOL: improved method 'induct' --- now handles non-atomic goals
  5006 (potential INCOMPATIBILITY); tuned error handling;
  5007 
  5008 * HOL: cases and induct rules now provide explicit hints about the
  5009 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5010 any remaining facts are inserted into the goal verbatim;
  5011 
  5012 * HOL: local contexts (aka cases) may now contain term bindings as
  5013 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5014 the result to be shown in each case;
  5015 
  5016 * HOL: added 'recdef_tc' command;
  5017 
  5018 * isatool convert assists in eliminating legacy ML scripts;
  5019 
  5020 
  5021 *** HOL ***
  5022 
  5023 * HOL/Library: a collection of generic theories to be used together
  5024 with main HOL; the theory loader path already includes this directory
  5025 by default; the following existing theories have been moved here:
  5026 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5027 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5028 
  5029 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5030 modelling and verification task performed in Isabelle/HOL +
  5031 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5032 
  5033 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5034 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5035 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5036 'domain', this makes the theory consistent with mathematical
  5037 literature;
  5038 
  5039 * HOL basics: added overloaded operations "inverse" and "divide"
  5040 (infix "/"), syntax for generic "abs" operation, generic summation
  5041 operator \<Sum>;
  5042 
  5043 * HOL/typedef: simplified package, provide more useful rules (see also
  5044 HOL/subset.thy);
  5045 
  5046 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5047 now expressed as a proper nested rule (old-style tactic scripts may
  5048 require atomize_strip_tac to cope with non-atomic premises);
  5049 
  5050 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5051 to "split_conv" (old name still available for compatibility);
  5052 
  5053 * HOL: improved concrete syntax for strings (e.g. allows translation
  5054 rules with string literals);
  5055 
  5056 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5057  and Fleuriot's mechanization of analysis, including the transcendental
  5058  functions for the reals;
  5059 
  5060 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5061 
  5062 
  5063 *** CTT ***
  5064 
  5065 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5066 "lam" is displayed as TWO lambda-symbols
  5067 
  5068 * CTT: theory Main now available, containing everything (that is, Bool
  5069 and Arith);
  5070 
  5071 
  5072 *** General ***
  5073 
  5074 * Pure: the Simplifier has been implemented properly as a derived rule
  5075 outside of the actual kernel (at last!); the overall performance
  5076 penalty in practical applications is about 50%, while reliability of
  5077 the Isabelle inference kernel has been greatly improved;
  5078 
  5079 * print modes "brackets" and "no_brackets" control output of nested =>
  5080 (types) and ==> (props); the default behaviour is "brackets";
  5081 
  5082 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5083 as assumptions as well;
  5084 
  5085 * system: support Poly/ML 4.0;
  5086 
  5087 * system: isatool install handles KDE version 1 or 2;
  5088 
  5089 
  5090 
  5091 New in Isabelle99-1 (October 2000)
  5092 ----------------------------------
  5093 
  5094 *** Overview of INCOMPATIBILITIES ***
  5095 
  5096 * HOL: simplification of natural numbers is much changed; to partly
  5097 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5098 issue the following ML commands:
  5099 
  5100   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5101   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5102 
  5103 * HOL: simplification no longer dives into case-expressions; this is
  5104 controlled by "t.weak_case_cong" for each datatype t;
  5105 
  5106 * HOL: nat_less_induct renamed to less_induct;
  5107 
  5108 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5109 fixsome to patch .thy and .ML sources automatically;
  5110 
  5111   select_equality  -> some_equality
  5112   select_eq_Ex     -> some_eq_ex
  5113   selectI2EX       -> someI2_ex
  5114   selectI2         -> someI2
  5115   selectI          -> someI
  5116   select1_equality -> some1_equality
  5117   Eps_sym_eq       -> some_sym_eq_trivial
  5118   Eps_eq           -> some_eq_trivial
  5119 
  5120 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5121 
  5122 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5123 instead);
  5124 
  5125 * HOL: the recursion equations generated by 'recdef' are now called
  5126 f.simps instead of f.rules;
  5127 
  5128 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5129 
  5130 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5131 sometimes be needed;
  5132 
  5133 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5134 
  5135 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5136 
  5137 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5138 product is now "<*>" instead of "Times"; the lexicographic product is
  5139 now "<*lex*>" instead of "**";
  5140 
  5141 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5142 of main HOL, but was unused); better use HOL's datatype package;
  5143 
  5144 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5145 the old syntax may be recovered as follows:
  5146 
  5147   syntax (symbols)
  5148     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5149       (infixl "\\<oplus>" 100)
  5150 
  5151 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5152 
  5153 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5154 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5155 internally;
  5156 
  5157 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5158 changed from A/r to A//r;
  5159 
  5160 * ZF: new treatment of arithmetic (nat & int) may break some old
  5161 proofs;
  5162 
  5163 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5164 rulify -> rule_format, elimify -> elim_format, ...);
  5165 
  5166 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5167 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5168 should have to change intro!! to intro? only); replaced "delrule" by
  5169 "rule del";
  5170 
  5171 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5172 
  5173 * Provers: strengthened force_tac by using new first_best_tac;
  5174 
  5175 * LaTeX document preparation: several changes of isabelle.sty (see
  5176 lib/texinputs);
  5177 
  5178 
  5179 *** Document preparation ***
  5180 
  5181 * formal comments (text blocks etc.) in new-style theories may now
  5182 contain antiquotations of thm/prop/term/typ/text to be presented
  5183 according to latex print mode; concrete syntax is like this:
  5184 @{term[show_types] "f(x) = a + x"};
  5185 
  5186 * isatool mkdir provides easy setup of Isabelle session directories,
  5187 including proper document sources;
  5188 
  5189 * generated LaTeX sources are now deleted after successful run
  5190 (isatool document -c); may retain a copy somewhere else via -D option
  5191 of isatool usedir;
  5192 
  5193 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5194 style files, achieving self-contained LaTeX sources and simplifying
  5195 LaTeX debugging;
  5196 
  5197 * old-style theories now produce (crude) LaTeX output as well;
  5198 
  5199 * browser info session directories are now self-contained (may be put
  5200 on WWW server seperately); improved graphs of nested sessions; removed
  5201 graph for 'all sessions';
  5202 
  5203 * several improvements in isabelle style files; \isabellestyle{it}
  5204 produces fake math mode output; \isamarkupheader is now \section by
  5205 default; see lib/texinputs/isabelle.sty etc.;
  5206 
  5207 
  5208 *** Isar ***
  5209 
  5210 * Isar/Pure: local results and corresponding term bindings are now
  5211 subject to Hindley-Milner polymorphism (similar to ML); this
  5212 accommodates incremental type-inference very nicely;
  5213 
  5214 * Isar/Pure: new derived language element 'obtain' supports
  5215 generalized existence reasoning;
  5216 
  5217 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5218 support accumulation of results, without applying any rules yet;
  5219 useful to collect intermediate results without explicit name
  5220 references, and for use with transitivity rules with more than 2
  5221 premises;
  5222 
  5223 * Isar/Pure: scalable support for case-analysis type proofs: new
  5224 'case' language element refers to local contexts symbolically, as
  5225 produced by certain proof methods; internally, case names are attached
  5226 to theorems as "tags";
  5227 
  5228 * Isar/Pure: theory command 'hide' removes declarations from
  5229 class/type/const name spaces;
  5230 
  5231 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5232 indicate potential overloading;
  5233 
  5234 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5235 
  5236 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5237 "{a,b,c}" instead of {a,b,c};
  5238 
  5239 * Isar/Pure now provides its own version of intro/elim/dest
  5240 attributes; useful for building new logics, but beware of confusion
  5241 with the version in Provers/classical;
  5242 
  5243 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5244 case name 'antecedent';
  5245 
  5246 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5247 to the current context is now done automatically);
  5248 
  5249 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5250 for definining proof methods in ML;
  5251 
  5252 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5253 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5254 most cases, one should have to change intro!! to intro? only);
  5255 replaced "delrule" by "rule del";
  5256 
  5257 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5258 'symmetric' attribute (the latter supercedes [RS sym]);
  5259 
  5260 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5261 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5262 well (including splits);
  5263 
  5264 * Isar/Provers: Simplifier and Classical methods now support all kind
  5265 of modifiers used in the past, including 'cong', 'iff', etc.
  5266 
  5267 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5268 of Simplifier and Classical reasoner);
  5269 
  5270 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5271 now support named cases; major packages (inductive, datatype, primrec,
  5272 recdef) support case names and properly name parameters;
  5273 
  5274 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5275 monotonicity conditions are extracted to be proven at end of
  5276 calculations;
  5277 
  5278 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5279 method anyway;
  5280 
  5281 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5282 split_if split_if_asm; datatype package provides theorems foo.splits =
  5283 foo.split foo.split_asm for each datatype;
  5284 
  5285 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5286 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5287 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5288 use "(cases (simplified))" method in proper proof texts);
  5289 
  5290 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5291 
  5292 * Isar: names of theorems etc. may be natural numbers as well;
  5293 
  5294 * Isar: 'pr' command: optional arguments for goals_limit and
  5295 ProofContext.prems_limit; no longer prints theory contexts, but only
  5296 proof states;
  5297 
  5298 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5299 additional print modes to be specified; e.g. "pr(latex)" will print
  5300 proof state according to the Isabelle LaTeX style;
  5301 
  5302 * Isar: improved support for emulating tactic scripts, including proof
  5303 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5304 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5305 (for HOL datatypes);
  5306 
  5307 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5308 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5309 'proof method scripts' have to be in depth-first order;
  5310 
  5311 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5312 
  5313 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5314 should instead use individual commands for printing items
  5315 (print_commands, print_methods etc.);
  5316 
  5317 * Isar: added 'nothing' --- the empty list of theorems;
  5318 
  5319 
  5320 *** HOL ***
  5321 
  5322 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5323 corresponding virtual machine and a specification of its bytecode
  5324 verifier and a lightweight bytecode verifier, including proofs of
  5325 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5326 Cornelia Pusch (see also the homepage of project Bali at
  5327 http://isabelle.in.tum.de/Bali/);
  5328 
  5329 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5330 Clemens Ballarin;
  5331 
  5332 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5333 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5334 Rasmussen;
  5335 
  5336 * HOL/Lattice: fundamental concepts of lattice theory and order
  5337 structures, including duals, properties of bounds versus algebraic
  5338 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5339 Theorem for complete lattices etc.; may also serve as a demonstration
  5340 for abstract algebraic reasoning using axiomatic type classes, and
  5341 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5342 
  5343 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5344 von Oheimb;
  5345 
  5346 * HOL/IMPP: extension of IMP with local variables and mutually
  5347 recursive procedures, by David von Oheimb;
  5348 
  5349 * HOL/Lambda: converted into new-style theory and document;
  5350 
  5351 * HOL/ex/Multiquote: example of multiple nested quotations and
  5352 anti-quotations -- basically a generalized version of de-Bruijn
  5353 representation; very useful in avoiding lifting of operations;
  5354 
  5355 * HOL/record: added general record equality rule to simpset; fixed
  5356 select-update simplification procedure to handle extended records as
  5357 well; admit "r" as field name;
  5358 
  5359 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5360 other numeric types and also as the identity of groups, rings, etc.;
  5361 
  5362 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5363 Types nat and int belong to this axclass;
  5364 
  5365 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5366    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5367    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5368   two terms #m*u and #n*u are replaced by #(m+n)*u
  5369     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5370   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5371     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5372 
  5373 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5374 powerful prover for predicate logic but knows nothing of clasets; see
  5375 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5376 
  5377 * HOL: new version of "case_tac" subsumes both boolean case split and
  5378 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5379 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5380 
  5381 * HOL: simplification no longer dives into case-expressions: only the
  5382 selector expression is simplified, but not the remaining arms; to
  5383 enable full simplification of case-expressions for datatype t, you may
  5384 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5385 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5386 
  5387 * HOL/recdef: the recursion equations generated by 'recdef' for
  5388 function 'f' are now called f.simps instead of f.rules; if all
  5389 termination conditions are proved automatically, these simplification
  5390 rules are added to the simpset, as in primrec; rules may be named
  5391 individually as well, resulting in a separate list of theorems for
  5392 each equation;
  5393 
  5394 * HOL/While is a new theory that provides a while-combinator. It
  5395 permits the definition of tail-recursive functions without the
  5396 provision of a termination measure. The latter is necessary once the
  5397 invariant proof rule for while is applied.
  5398 
  5399 * HOL: new (overloaded) notation for the set of elements below/above
  5400 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5401 
  5402 * HOL: theorems impI, allI, ballI bound as "strip";
  5403 
  5404 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5405 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5406 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5407 
  5408 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5409 
  5410 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5411 main HOL, but was unused);
  5412 
  5413 * HOL: fewer consts declared as global (e.g. have to refer to
  5414 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5415 
  5416 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5417 in case of overlap with user translations (e.g. judgements over
  5418 tuples); (note that the underlying logical represenation is still
  5419 bogus);
  5420 
  5421 
  5422 *** ZF ***
  5423 
  5424 * ZF: simplification automatically cancels common terms in arithmetic
  5425 expressions over nat and int;
  5426 
  5427 * ZF: new treatment of nat to minimize type-checking: all operators
  5428 coerce their operands to a natural number using the function natify,
  5429 making the algebraic laws unconditional;
  5430 
  5431 * ZF: as above, for int: operators coerce their operands to an integer
  5432 using the function intify;
  5433 
  5434 * ZF: the integer library now contains many of the usual laws for the
  5435 orderings, including $<=, and monotonicity laws for $+ and $*;
  5436 
  5437 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5438 simplification;
  5439 
  5440 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5441 to the simplifier and classical reasoner simultaneously;
  5442 
  5443 
  5444 *** General ***
  5445 
  5446 * Provers: blast_tac now handles actual object-logic rules as
  5447 assumptions; note that auto_tac uses blast_tac internally as well;
  5448 
  5449 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5450 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5451 
  5452 * Provers: delrules now handles destruct rules as well (no longer need
  5453 explicit make_elim);
  5454 
  5455 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5456   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5457 use instead the strong form,
  5458   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5459 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5460 from destruct-rules;
  5461 
  5462 * Provers: Simplifier.easy_setup provides a fast path to basic
  5463 Simplifier setup for new object-logics;
  5464 
  5465 * Pure: AST translation rules no longer require constant head on LHS;
  5466 
  5467 * Pure: improved name spaces: ambiguous output is qualified; support
  5468 for hiding of names;
  5469 
  5470 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5471 XSYMBOL_HOME; no longer need to do manual configuration in most
  5472 situations;
  5473 
  5474 * system: compression of ML heaps images may now be controlled via -c
  5475 option of isabelle and isatool usedir (currently only observed by
  5476 Poly/ML);
  5477 
  5478 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5479 useful for remote X11);
  5480 
  5481 * system: provide TAGS file for Isabelle sources;
  5482 
  5483 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5484 order;
  5485 
  5486 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5487 timing flag supersedes proof_timing and Toplevel.trace;
  5488 
  5489 * ML: new combinators |>> and |>>> for incremental transformations
  5490 with secondary results (e.g. certain theory extensions):
  5491 
  5492 * ML: PureThy.add_defs gets additional argument to indicate potential
  5493 overloading (usually false);
  5494 
  5495 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5496 results;
  5497 
  5498 
  5499 
  5500 New in Isabelle99 (October 1999)
  5501 --------------------------------
  5502 
  5503 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5504 
  5505 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5506 are no longer simplified.  (This allows the simplifier to unfold recursive
  5507 functional programs.)  To restore the old behaviour, declare
  5508 
  5509     Delcongs [if_weak_cong];
  5510 
  5511 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5512 complement;
  5513 
  5514 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5515 
  5516 * HOL/datatype: mutual_induct_tac no longer exists --
  5517   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5518 
  5519 * HOL/typedef: fixed type inference for representing set; type
  5520 arguments now have to occur explicitly on the rhs as type constraints;
  5521 
  5522 * ZF: The con_defs part of an inductive definition may no longer refer
  5523 to constants declared in the same theory;
  5524 
  5525 * HOL, ZF: the function mk_cases, generated by the inductive
  5526 definition package, has lost an argument.  To simplify its result, it
  5527 uses the default simpset instead of a supplied list of theorems.
  5528 
  5529 * HOL/List: the constructors of type list are now Nil and Cons;
  5530 
  5531 * Simplifier: the type of the infix ML functions
  5532         setSSolver addSSolver setSolver addSolver
  5533 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5534 for packaging solvers. A solver is created via
  5535         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5536 where the string argument is only a comment.
  5537 
  5538 
  5539 *** Proof tools ***
  5540 
  5541 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5542 decision procedure for linear arithmetic. Currently it is used for
  5543 types `nat', `int', and `real' in HOL (see below); it can, should and
  5544 will be instantiated for other types and logics as well.
  5545 
  5546 * The simplifier now accepts rewrite rules with flexible heads, eg
  5547      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5548   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5549   matching.
  5550 
  5551 
  5552 *** General ***
  5553 
  5554 * New Isabelle/Isar subsystem provides an alternative to traditional
  5555 tactical theorem proving; together with the ProofGeneral/isar user
  5556 interface it offers an interactive environment for developing human
  5557 readable proof documents (Isar == Intelligible semi-automated
  5558 reasoning); for further information see isatool doc isar-ref,
  5559 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5560 
  5561 * improved and simplified presentation of theories: better HTML markup
  5562 (including colors), graph views in several sizes; isatool usedir now
  5563 provides a proper interface for user theories (via -P option); actual
  5564 document preparation based on (PDF)LaTeX is available as well (for
  5565 new-style theories only); see isatool doc system for more information;
  5566 
  5567 * native support for Proof General, both for classic Isabelle and
  5568 Isabelle/Isar;
  5569 
  5570 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5571 using the graph browser tool;
  5572 
  5573 * Isabelle manuals now also available as PDF;
  5574 
  5575 * theory loader rewritten from scratch (may not be fully
  5576 bug-compatible); old loadpath variable has been replaced by show_path,
  5577 add_path, del_path, reset_path functions; new operations such as
  5578 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5579 isatool doc ref);
  5580 
  5581 * improved isatool install: option -k creates KDE application icon,
  5582 option -p DIR installs standalone binaries;
  5583 
  5584 * added ML_PLATFORM setting (useful for cross-platform installations);
  5585 more robust handling of platform specific ML images for SML/NJ;
  5586 
  5587 * the settings environment is now statically scoped, i.e. it is never
  5588 created again in sub-processes invoked from isabelle, isatool, or
  5589 Isabelle;
  5590 
  5591 * path element specification '~~' refers to '$ISABELLE_HOME';
  5592 
  5593 * in locales, the "assumes" and "defines" parts may be omitted if
  5594 empty;
  5595 
  5596 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5597 long arrows);
  5598 
  5599 * new print_mode "HTML";
  5600 
  5601 * new flag show_tags controls display of tags of theorems (which are
  5602 basically just comments that may be attached by some tools);
  5603 
  5604 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5605 mode and goal output format:
  5606 
  5607 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5608 244c244
  5609 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5610 ---
  5611 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5612 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5613 181c181
  5614 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5615 ---
  5616 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5617 
  5618 * function bind_thms stores lists of theorems (cf. bind_thm);
  5619 
  5620 * new shorthand tactics ftac, eatac, datac, fatac;
  5621 
  5622 * qed (and friends) now accept "" as result name; in that case the
  5623 theorem is not stored, but proper checks and presentation of the
  5624 result still apply;
  5625 
  5626 * theorem database now also indexes constants "Trueprop", "all",
  5627 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5628 
  5629 
  5630 *** HOL ***
  5631 
  5632 ** HOL arithmetic **
  5633 
  5634 * There are now decision procedures for linear arithmetic over nat and
  5635 int:
  5636 
  5637 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5638 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5639 are treated as atomic; subformulae not involving type `nat' or `int'
  5640 are ignored; quantified subformulae are ignored unless they are
  5641 positive universal or negative existential. The tactic has to be
  5642 invoked by hand and can be a little bit slow. In particular, the
  5643 running time is exponential in the number of occurrences of `min' and
  5644 `max', and `-' on `nat'.
  5645 
  5646 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5647 (negated) (in)equalities among the premises and the conclusion into
  5648 account (i.e. no compound formulae) and does not know about `min' and
  5649 `max', and `-' on `nat'. It is fast and is used automatically by the
  5650 simplifier.
  5651 
  5652 NB: At the moment, these decision procedures do not cope with mixed
  5653 nat/int formulae where the two parts interact, such as `m < n ==>
  5654 int(m) < int(n)'.
  5655 
  5656 * HOL/Numeral provides a generic theory of numerals (encoded
  5657 efficiently as bit strings); setup for types nat/int/real is in place;
  5658 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5659 int, existing theories and proof scripts may require a few additional
  5660 type constraints;
  5661 
  5662 * integer division and remainder can now be performed on constant
  5663 arguments;
  5664 
  5665 * many properties of integer multiplication, division and remainder
  5666 are now available;
  5667 
  5668 * An interface to the Stanford Validity Checker (SVC) is available through the
  5669 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5670 are proved automatically.  SVC must be installed separately, and its results
  5671 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5672 invocation of the underlying oracle).  For SVC see
  5673   http://verify.stanford.edu/SVC
  5674 
  5675 * IsaMakefile: the HOL-Real target now builds an actual image;
  5676 
  5677 
  5678 ** HOL misc **
  5679 
  5680 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5681 (in Isabelle/Isar) -- by Gertrud Bauer;
  5682 
  5683 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5684 analysis for assembly languages with subtypes;
  5685 
  5686 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5687 -- avoids syntactic ambiguities and treats state, transition, and
  5688 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5689 changed syntax and (many) tactics;
  5690 
  5691 * HOL/inductive: Now also handles more general introduction rules such
  5692   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5693   theorems are now maintained within the theory (maintained via the
  5694   "mono" attribute);
  5695 
  5696 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5697   (using function types) such as
  5698 
  5699   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5700 
  5701 * HOL/record: record_simproc (part of the default simpset) takes care
  5702 of selectors applied to updated records; record_split_tac is no longer
  5703 part of the default claset; update_defs may now be removed from the
  5704 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5705 
  5706   claset_ref () := claset() addSWrapper record_split_wrapper;
  5707   Delsimprocs [record_simproc]
  5708 
  5709 * HOL/typedef: fixed type inference for representing set; type
  5710 arguments now have to occur explicitly on the rhs as type constraints;
  5711 
  5712 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5713 names rather than an ML expression;
  5714 
  5715 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5716 supplied later.  Program schemes can be defined, such as
  5717     "While B C s = (if B s then While B C (C s) else s)"
  5718 where the well-founded relation can be chosen after B and C have been given.
  5719 
  5720 * HOL/List: the constructors of type list are now Nil and Cons;
  5721 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5722 course, ML tools referring to List.list.op # etc. have to be adapted;
  5723 
  5724 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5725 disabled by default; run isabelle with option -m HOL to get back to
  5726 the original Gordon/HOL-style output;
  5727 
  5728 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5729 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5730 
  5731 * HOL basic syntax simplified (more orthogonal): all variants of
  5732 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5733 Eps operator is provided as well: "SOME x. P[x]";
  5734 
  5735 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5736 
  5737 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5738 thus available for user theories;
  5739 
  5740 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5741 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5742 time;
  5743 
  5744 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5745 several times and then mp;
  5746 
  5747 
  5748 *** LK ***
  5749 
  5750 * the notation <<...>> is now available as a notation for sequences of
  5751 formulas;
  5752 
  5753 * the simplifier is now installed
  5754 
  5755 * the axiom system has been generalized (thanks to Soren Heilmann)
  5756 
  5757 * the classical reasoner now has a default rule database
  5758 
  5759 
  5760 *** ZF ***
  5761 
  5762 * new primrec section allows primitive recursive functions to be given
  5763 directly (as in HOL) over datatypes and the natural numbers;
  5764 
  5765 * new tactics induct_tac and exhaust_tac for induction (or case
  5766 analysis) over datatypes and the natural numbers;
  5767 
  5768 * the datatype declaration of type T now defines the recursor T_rec;
  5769 
  5770 * simplification automatically does freeness reasoning for datatype
  5771 constructors;
  5772 
  5773 * automatic type-inference, with AddTCs command to insert new
  5774 type-checking rules;
  5775 
  5776 * datatype introduction rules are now added as Safe Introduction rules
  5777 to the claset;
  5778 
  5779 * the syntax "if P then x else y" is now available in addition to
  5780 if(P,x,y);
  5781 
  5782 
  5783 *** Internal programming interfaces ***
  5784 
  5785 * tuned simplifier trace output; new flag debug_simp;
  5786 
  5787 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5788 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5789 
  5790 * AxClass.axclass_tac lost the theory argument;
  5791 
  5792 * tuned current_goals_markers semantics: begin / end goal avoids
  5793 printing empty lines;
  5794 
  5795 * removed prs and prs_fn hook, which was broken because it did not
  5796 include \n in its semantics, forcing writeln to add one
  5797 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5798 string -> unit if you really want to output text without newline;
  5799 
  5800 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5801 plain output, interface builders may have to enable 'isabelle_font'
  5802 mode to get Isabelle font glyphs as before;
  5803 
  5804 * refined token_translation interface; INCOMPATIBILITY: output length
  5805 now of type real instead of int;
  5806 
  5807 * theory loader actions may be traced via new ThyInfo.add_hook
  5808 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5809 your own database of information attached to *whole* theories -- as
  5810 opposed to intra-theory data slots offered via TheoryDataFun;
  5811 
  5812 * proper handling of dangling sort hypotheses (at last!);
  5813 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5814 extra sort hypotheses that can be witnessed from the type signature;
  5815 the force_strip_shyps flag is gone, any remaining shyps are simply
  5816 left in the theorem (with a warning issued by strip_shyps_warning);
  5817 
  5818 
  5819 
  5820 New in Isabelle98-1 (October 1998)
  5821 ----------------------------------
  5822 
  5823 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5824 
  5825 * several changes of automated proof tools;
  5826 
  5827 * HOL: major changes to the inductive and datatype packages, including
  5828 some minor incompatibilities of theory syntax;
  5829 
  5830 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5831 called `inj_on';
  5832 
  5833 * HOL: removed duplicate thms in Arith:
  5834   less_imp_add_less  should be replaced by  trans_less_add1
  5835   le_imp_add_le      should be replaced by  trans_le_add1
  5836 
  5837 * HOL: unary minus is now overloaded (new type constraints may be
  5838 required);
  5839 
  5840 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5841 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5842 now taken as an integer constant.
  5843 
  5844 * Pure: ML function 'theory_of' renamed to 'theory';
  5845 
  5846 
  5847 *** Proof tools ***
  5848 
  5849 * Simplifier:
  5850   1. Asm_full_simp_tac is now more aggressive.
  5851      1. It will sometimes reorient premises if that increases their power to
  5852         simplify.
  5853      2. It does no longer proceed strictly from left to right but may also
  5854         rotate premises to achieve further simplification.
  5855      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5856      old Asm_full_simp_tac in that it does not rotate premises.
  5857   2. The simplifier now knows a little bit about nat-arithmetic.
  5858 
  5859 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5860 allows for selected deletion of wrappers, by introduction of names for
  5861 wrapper functionals.  This implies that addbefore, addSbefore,
  5862 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5863 and that adding two tactics with the same name overwrites the first
  5864 one (emitting a warning).
  5865   type wrapper = (int -> tactic) -> (int -> tactic)
  5866   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5867   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5868   delWrapper, delSWrapper: claset *  string            -> claset
  5869   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5870 
  5871 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5872 semantics; addbefore now affects only the unsafe part of step_tac
  5873 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5874 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5875 by Force_tac;
  5876 
  5877 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5878 compWrapper; added safe wrapper (and access functions for it);
  5879 
  5880 * HOL/split_all_tac is now much faster and fails if there is nothing
  5881 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5882 and the names of the automatically generated variables have changed.
  5883 split_all_tac has moved within claset() from unsafe wrappers to safe
  5884 wrappers, which means that !!-bound variables are split much more
  5885 aggressively, and safe_tac and clarify_tac now split such variables.
  5886 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5887 Note: the same holds for record_split_tac, which does the job of
  5888 split_all_tac for record fields.
  5889 
  5890 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5891 permanently to the default simpset using Addsplits just like
  5892 Addsimps. They can be removed via Delsplits just like
  5893 Delsimps. Lower-case versions are also available.
  5894 
  5895 * HOL/Simplifier: The rule split_if is now part of the default
  5896 simpset. This means that the simplifier will eliminate all occurrences
  5897 of if-then-else in the conclusion of a goal. To prevent this, you can
  5898 either remove split_if completely from the default simpset by
  5899 `Delsplits [split_if]' or remove it in a specific call of the
  5900 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5901 other case splitting rules to/from the default simpset: every datatype
  5902 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5903 t is the name of the datatype).
  5904 
  5905 * Classical reasoner / Simplifier combination: new force_tac (and
  5906 derivatives Force_tac, force) combines rewriting and classical
  5907 reasoning (and whatever other tools) similarly to auto_tac, but is
  5908 aimed to solve the given subgoal completely.
  5909 
  5910 
  5911 *** General ***
  5912 
  5913 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5914 and `goalw': the theory is no longer needed as an explicit argument -
  5915 the current theory context is used; assumptions are no longer returned
  5916 at the ML-level unless one of them starts with ==> or !!; it is
  5917 recommended to convert to these new commands using isatool fixgoal
  5918 (backup your sources first!);
  5919 
  5920 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5921 the current theory context, and 'theory' to lookup stored theories;
  5922 
  5923 * new theory section 'locale' for declaring constants, assumptions and
  5924 definitions that have local scope;
  5925 
  5926 * new theory section 'nonterminals' for purely syntactic types;
  5927 
  5928 * new theory section 'setup' for generic ML setup functions
  5929 (e.g. package initialization);
  5930 
  5931 * the distribution now includes Isabelle icons: see
  5932 lib/logo/isabelle-{small,tiny}.xpm;
  5933 
  5934 * isatool install - install binaries with absolute references to
  5935 ISABELLE_HOME/bin;
  5936 
  5937 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5938 
  5939 * print mode 'emacs' reserved for Isamode;
  5940 
  5941 * support multiple print (ast) translations per constant name;
  5942 
  5943 * theorems involving oracles are now printed with a suffixed [!];
  5944 
  5945 
  5946 *** HOL ***
  5947 
  5948 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5949 
  5950 * HOL/inductive package reorganized and improved: now supports mutual
  5951 definitions such as
  5952 
  5953   inductive EVEN ODD
  5954     intrs
  5955       null "0 : EVEN"
  5956       oddI "n : EVEN ==> Suc n : ODD"
  5957       evenI "n : ODD ==> Suc n : EVEN"
  5958 
  5959 new theorem list "elims" contains an elimination rule for each of the
  5960 recursive sets; inductive definitions now handle disjunctive premises
  5961 correctly (also ZF);
  5962 
  5963 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5964 "mutual_induct" no longer exists - the induction rule is always
  5965 contained in "induct";
  5966 
  5967 
  5968 * HOL/datatype package re-implemented and greatly improved: now
  5969 supports mutually recursive datatypes such as
  5970 
  5971   datatype
  5972     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5973             | SUM ('a aexp) ('a aexp)
  5974             | DIFF ('a aexp) ('a aexp)
  5975             | NUM 'a
  5976   and
  5977     'a bexp = LESS ('a aexp) ('a aexp)
  5978             | AND ('a bexp) ('a bexp)
  5979             | OR ('a bexp) ('a bexp)
  5980 
  5981 as well as indirectly recursive datatypes such as
  5982 
  5983   datatype
  5984     ('a, 'b) term = Var 'a
  5985                   | App 'b ((('a, 'b) term) list)
  5986 
  5987 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5988 induction on mutually / indirectly recursive datatypes.
  5989 
  5990 Primrec equations are now stored in theory and can be accessed via
  5991 <function_name>.simps.
  5992 
  5993 INCOMPATIBILITIES:
  5994 
  5995   - Theories using datatypes must now have theory Datatype as an
  5996     ancestor.
  5997   - The specific <typename>.induct_tac no longer exists - use the
  5998     generic induct_tac instead.
  5999   - natE has been renamed to nat.exhaust - use exhaust_tac
  6000     instead of res_inst_tac ... natE. Note that the variable
  6001     names in nat.exhaust differ from the names in natE, this
  6002     may cause some "fragile" proofs to fail.
  6003   - The theorems split_<typename>_case and split_<typename>_case_asm
  6004     have been renamed to <typename>.split and <typename>.split_asm.
  6005   - Since default sorts of type variables are now handled correctly,
  6006     some datatype definitions may have to be annotated with explicit
  6007     sort constraints.
  6008   - Primrec definitions no longer require function name and type
  6009     of recursive argument.
  6010 
  6011 Consider using isatool fixdatatype to adapt your theories and proof
  6012 scripts to the new package (backup your sources first!).
  6013 
  6014 
  6015 * HOL/record package: considerably improved implementation; now
  6016 includes concrete syntax for record types, terms, updates; theorems
  6017 for surjective pairing and splitting !!-bound record variables; proof
  6018 support is as follows:
  6019 
  6020   1) standard conversions (selectors or updates applied to record
  6021 constructor terms) are part of the standard simpset;
  6022 
  6023   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  6024 made part of standard simpset and claset via addIffs;
  6025 
  6026   3) a tactic for record field splitting (record_split_tac) is part of
  6027 the standard claset (addSWrapper);
  6028 
  6029 To get a better idea about these rules you may retrieve them via
  6030 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  6031 the name of your record type.
  6032 
  6033 The split tactic 3) conceptually simplifies by the following rule:
  6034 
  6035   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  6036 
  6037 Thus any record variable that is bound by meta-all will automatically
  6038 blow up into some record constructor term, consequently the
  6039 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  6040 solve record problems automatically.
  6041 
  6042 
  6043 * reorganized the main HOL image: HOL/Integ and String loaded by
  6044 default; theory Main includes everything;
  6045 
  6046 * automatic simplification of integer sums and comparisons, using cancellation;
  6047 
  6048 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  6049 
  6050 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  6051 
  6052 * many new identities for unions, intersections, set difference, etc.;
  6053 
  6054 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  6055 called split_if, split_split, split_sum_case and split_nat_case (to go
  6056 with add/delsplits);
  6057 
  6058 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  6059 (?x::unit) = (); this is made part of the default simpset, which COULD
  6060 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  6061 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  6062 unit_abs_eta_conv is added in order to counter the effect of
  6063 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  6064 %u.f();
  6065 
  6066 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  6067 makes more sense);
  6068 
  6069 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6070   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6071   disjointness reasoning but breaking a few old proofs.
  6072 
  6073 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  6074 to 'converse' from 'inverse' (for compatibility with ZF and some
  6075 literature);
  6076 
  6077 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  6078 the well-founded relation;
  6079 
  6080 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  6081     Compl A.  The "Compl" syntax remains available as input syntax for this
  6082     release ONLY.
  6083 
  6084 * HOL/Update: new theory of function updates:
  6085     f(a:=b) == %x. if x=a then b else f x
  6086 may also be iterated as in f(a:=b,c:=d,...);
  6087 
  6088 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  6089 
  6090 * HOL/List:
  6091   - new function list_update written xs[i:=v] that updates the i-th
  6092     list position. May also be iterated as in xs[i:=a,j:=b,...].
  6093   - new function `upt' written [i..j(] which generates the list
  6094     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  6095     bound write [i..j], which is a shorthand for [i..j+1(].
  6096   - new lexicographic orderings and corresponding wellfoundedness theorems.
  6097 
  6098 * HOL/Arith:
  6099   - removed 'pred' (predecessor) function;
  6100   - generalized some theorems about n-1;
  6101   - many new laws about "div" and "mod";
  6102   - new laws about greatest common divisors (see theory ex/Primes);
  6103 
  6104 * HOL/Relation: renamed the relational operator r^-1 "converse"
  6105 instead of "inverse";
  6106 
  6107 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  6108   of the multiset ordering;
  6109 
  6110 * directory HOL/Real: a construction of the reals using Dedekind cuts
  6111   (not included by default);
  6112 
  6113 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  6114 
  6115 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  6116   programs, i.e. different program variables may have different types.
  6117 
  6118 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6119   [previously, this check worked only if the rewrite rule was unconditional]
  6120   Now rew can involve either definitions or equalities (either == or =).
  6121 
  6122 
  6123 *** ZF ***
  6124 
  6125 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  6126   only the theorems proved on ZF.ML;
  6127 
  6128 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6129   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6130   disjointness reasoning but breaking a few old proofs.
  6131 
  6132 * ZF/Update: new theory of function updates
  6133     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  6134   may also be iterated as in f(a:=b,c:=d,...);
  6135 
  6136 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6137 
  6138 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6139   [previously, this check worked only if the rewrite rule was unconditional]
  6140   Now rew can involve either definitions or equalities (either == or =).
  6141 
  6142 * case_tac provided for compatibility with HOL
  6143     (like the old excluded_middle_tac, but with subgoals swapped)
  6144 
  6145 
  6146 *** Internal programming interfaces ***
  6147 
  6148 * Pure: several new basic modules made available for general use, see
  6149 also src/Pure/README;
  6150 
  6151 * improved the theory data mechanism to support encapsulation (data
  6152 kind name replaced by private Object.kind, acting as authorization
  6153 key); new type-safe user interface via functor TheoryDataFun; generic
  6154 print_data function becomes basically useless;
  6155 
  6156 * removed global_names compatibility flag -- all theory declarations
  6157 are qualified by default;
  6158 
  6159 * module Pure/Syntax now offers quote / antiquote translation
  6160 functions (useful for Hoare logic etc. with implicit dependencies);
  6161 see HOL/ex/Antiquote for an example use;
  6162 
  6163 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  6164 cterm -> thm;
  6165 
  6166 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  6167 subgoal;
  6168 
  6169 * Display.print_goals function moved to Locale.print_goals;
  6170 
  6171 * standard print function for goals supports current_goals_markers
  6172 variable for marking begin of proof, end of proof, start of goal; the
  6173 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  6174 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  6175 for example;
  6176 
  6177 
  6178 
  6179 New in Isabelle98 (January 1998)
  6180 --------------------------------
  6181 
  6182 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6183 
  6184 * changed lexical syntax of terms / types: dots made part of long
  6185 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6186 
  6187 * simpset (and claset) reference variable replaced by functions
  6188 simpset / simpset_ref;
  6189 
  6190 * no longer supports theory aliases (via merge) and non-trivial
  6191 implicit merge of thms' signatures;
  6192 
  6193 * most internal names of constants changed due to qualified names;
  6194 
  6195 * changed Pure/Sequence interface (see Pure/seq.ML);
  6196 
  6197 
  6198 *** General Changes ***
  6199 
  6200 * hierachically structured name spaces (for consts, types, axms, thms
  6201 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6202 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6203 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6204 long_names for fully qualified output names; NOTE: ML programs
  6205 (special tactics, packages etc.) referring to internal names may have
  6206 to be adapted to cope with fully qualified names; in case of severe
  6207 backward campatibility problems try setting 'global_names' at compile
  6208 time to have enrything declared within a flat name space; one may also
  6209 fine tune name declarations in theories via the 'global' and 'local'
  6210 section;
  6211 
  6212 * reimplemented the implicit simpset and claset using the new anytype
  6213 data filed in signatures; references simpset:simpset ref etc. are
  6214 replaced by functions simpset:unit->simpset and
  6215 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6216 to patch your ML files accordingly;
  6217 
  6218 * HTML output now includes theory graph data for display with Java
  6219 applet or isatool browser; data generated automatically via isatool
  6220 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6221 
  6222 * defs may now be conditional; improved rewrite_goals_tac to handle
  6223 conditional equations;
  6224 
  6225 * defs now admits additional type arguments, using TYPE('a) syntax;
  6226 
  6227 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6228 creates a new theory node; implicit merge of thms' signatures is
  6229 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6230 transfer:theory->thm->thm in (rare) cases;
  6231 
  6232 * improved handling of draft signatures / theories; draft thms (and
  6233 ctyps, cterms) are automatically promoted to real ones;
  6234 
  6235 * slightly changed interfaces for oracles: admit many per theory, named
  6236 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  6237 
  6238 * print_goals: optional output of const types (set show_consts and
  6239 show_types);
  6240 
  6241 * improved output of warnings (###) and errors (***);
  6242 
  6243 * subgoal_tac displays a warning if the new subgoal has type variables;
  6244 
  6245 * removed