NEWS
author haftmann
Wed Feb 10 14:12:30 2010 +0100 (2010-02-10)
changeset 35093 5acba118b02a
parent 35084 e25eedfc15ce
child 35100 53754ec7360b
permissions -rw-r--r--
NEWS
     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 * New set of rules "ac_simps" provides combined assoc / commute rewrites
    16 for all interpretations of the appropriate generic locales.
    17 
    18 * Renamed theory "OrderedGroup" to "Groups" and split theory "Ring_and_Field"
    19 into theories "Rings" and "Fields";  for more appropriate and more
    20 consistent names suitable for name prefixes within the HOL theories.
    21 INCOMPATIBILITY.
    22 
    23 * Some generic constants have been put to appropriate theories:
    24 
    25     less_eq, less: Orderings
    26     abs, sgn: Groups
    27     inverse, divide: Rings
    28 
    29 INCOMPATIBILITY.
    30 
    31 * Class division ring also requires proof of fact divide_inverse.  However instantiation
    32 of parameter divide has also been required previously.  INCOMPATIBILITY.
    33 
    34 * More consistent naming of type classes involving orderings (and lattices):
    35 
    36     lower_semilattice                   ~> semilattice_inf
    37     upper_semilattice                   ~> semilattice_sup
    38 
    39     dense_linear_order                  ~> dense_linorder
    40 
    41     pordered_ab_group_add               ~> ordered_ab_group_add
    42     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
    43     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
    44     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
    45     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
    46     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
    47     pordered_cancel_semiring            ~> ordered_cancel_semiring
    48     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
    49     pordered_comm_ring                  ~> ordered_comm_ring
    50     pordered_comm_semiring              ~> ordered_comm_semiring
    51     pordered_ring                       ~> ordered_ring
    52     pordered_ring_abs                   ~> ordered_ring_abs
    53     pordered_semiring                   ~> ordered_semiring
    54 
    55     ordered_ab_group_add                ~> linordered_ab_group_add
    56     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
    57     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
    58     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
    59     ordered_field                       ~> linordered_field
    60     ordered_field_no_lb                 ~> linordered_field_no_lb
    61     ordered_field_no_ub                 ~> linordered_field_no_ub
    62     ordered_field_dense_linear_order    ~> dense_linordered_field
    63     ordered_idom                        ~> linordered_idom
    64     ordered_ring                        ~> linordered_ring
    65     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
    66     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
    67     ordered_ring_strict                 ~> linordered_ring_strict
    68     ordered_semidom                     ~> linordered_semidom
    69     ordered_semiring                    ~> linordered_semiring
    70     ordered_semiring_1                  ~> linordered_semiring_1
    71     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
    72     ordered_semiring_strict             ~> linordered_semiring_strict
    73 
    74   The following slightly odd type classes have been moved to
    75   a separate theory Library/Lattice_Algebras.thy:
    76 
    77     lordered_ab_group_add               ~> lattice_ab_group_add
    78     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
    79     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
    80     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
    81     lordered_ring                       ~> lattice_ring
    82 
    83 INCOMPATIBILITY.
    84 
    85 * New theory Algebras contains generic algebraic structures and
    86 generic algebraic operations.  INCOMPATIBILTY: constants zero, one,
    87 plus, minus, uminus and times have been moved from HOL.thy to Algebras.thy.
    88 
    89 * HOLogic.strip_psplit: types are returned in syntactic order, similar
    90 to other strip and tuple operations.  INCOMPATIBILITY.
    91 
    92 * Various old-style primrec specifications in the HOL theories have been
    93 replaced by new-style primrec, especially in theory List.  The corresponding
    94 constants now have authentic syntax.  INCOMPATIBILITY.
    95 
    96 * Reorganized theory Multiset: less duplication, less historical
    97 organization of sections, conversion from associations lists to
    98 multisets, rudimentary code generation.  Use insert_DiffM2 [symmetric]
    99 instead of elem_imp_eq_diff_union, if needed.  INCOMPATIBILITY.
   100 
   101 * Reorganized theory Sum_Type; Inl and Inr now have authentic syntax.
   102 INCOMPATIBILITY.
   103 
   104 * Code generation: ML and OCaml code is decorated with signatures.
   105 
   106 * Theory Complete_Lattice: lemmas top_def and bot_def have been
   107 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   108 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   109 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   110 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   111 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   112 
   113 * Theory Finite_Set and List: some lemmas have been generalized from
   114 sets to lattices:
   115 
   116   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   117   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   118   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   119   union_Union_fold_union        ~> sup_Sup_fold_sup
   120   Inter_fold_inter              ~> Inf_fold_inf
   121   Union_fold_union              ~> Sup_fold_sup
   122   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   123   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   124   INTER_fold_inter              ~> INFI_fold_inf
   125   UNION_fold_union              ~> SUPR_fold_sup
   126 
   127 * Theory List: added transpose.
   128 
   129 
   130 *** ML ***
   131 
   132 * Renamed old-style Drule.standard to Drule.export_without_context, to
   133 emphasize that this is in no way a standard operation.
   134 INCOMPATIBILITY.
   135 
   136 * Curried take and drop in library.ML; negative length is interpreted
   137 as infinity (as in chop).  INCOMPATIBILITY.
   138 
   139 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   140 usual for resolution.  Rare INCOMPATIBILITY.
   141 
   142 * Discontinued old TheoryDataFun with its copy/init operation -- data
   143 needs to be pure.  Functor Theory_Data_PP retains the traditional
   144 Pretty.pp argument to merge, which is absent in the standard
   145 Theory_Data version.
   146 
   147 
   148 *** System ***
   149 
   150 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   151 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   152 proof terms are enabled unconditionally in the new HOL-Proofs image.
   153 
   154 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   155 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   156 respectively.
   157 
   158 
   159 
   160 New in Isabelle2009-1 (December 2009)
   161 -------------------------------------
   162 
   163 *** General ***
   164 
   165 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   166 one backslash should be used, even in ML sources.
   167 
   168 
   169 *** Pure ***
   170 
   171 * Locale interpretation propagates mixins along the locale hierarchy.
   172 The currently only available mixins are the equations used to map
   173 local definitions to terms of the target domain of an interpretation.
   174 
   175 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   176 loc" to print all interpretations of locale "loc" in the theory.
   177 Interpretations in proofs are not shown.
   178 
   179 * Thoroughly revised locales tutorial.  New section on conditional
   180 interpretation.
   181 
   182 * On instantiation of classes, remaining undefined class parameters
   183 are formally declared.  INCOMPATIBILITY.
   184 
   185 
   186 *** Document preparation ***
   187 
   188 * New generalized style concept for printing terms: @{foo (style) ...}
   189 instead of @{foo_style style ...}  (old form is still retained for
   190 backward compatibility).  Styles can be also applied for
   191 antiquotations prop, term_type and typeof.
   192 
   193 
   194 *** HOL ***
   195 
   196 * New proof method "smt" for a combination of first-order logic with
   197 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   198 fixed-size bitvectors; there is also basic support for higher-order
   199 features (esp. lambda abstractions).  It is an incomplete decision
   200 procedure based on external SMT solvers using the oracle mechanism;
   201 for the SMT solver Z3, this method is proof-producing.  Certificates
   202 are provided to avoid calling the external solvers solely for
   203 re-checking proofs.  Due to a remote SMT service there is no need for
   204 installing SMT solvers locally.  See src/HOL/SMT.
   205 
   206 * New commands to load and prove verification conditions generated by
   207 the Boogie program verifier or derived systems (e.g. the Verifying C
   208 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   209 
   210 * New counterexample generator tool 'nitpick' based on the Kodkod
   211 relational model finder.  See src/HOL/Tools/Nitpick and
   212 src/HOL/Nitpick_Examples.
   213 
   214 * New commands 'code_pred' and 'values' to invoke the predicate
   215 compiler and to enumerate values of inductive predicates.
   216 
   217 * A tabled implementation of the reflexive transitive closure.
   218 
   219 * New implementation of quickcheck uses generic code generator;
   220 default generators are provided for all suitable HOL types, records
   221 and datatypes.  Old quickcheck can be re-activated importing theory
   222 Library/SML_Quickcheck.
   223 
   224 * New testing tool Mirabelle for automated proof tools.  Applies
   225 several tools and tactics like sledgehammer, metis, or quickcheck, to
   226 every proof step in a theory.  To be used in batch mode via the
   227 "mirabelle" utility.
   228 
   229 * New proof method "sos" (sum of squares) for nonlinear real
   230 arithmetic (originally due to John Harison). It requires theory
   231 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   232 works well in practice on quantifier-free real arithmetic with +, -,
   233 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   234 inequalities between polynomials.  It makes use of external
   235 semidefinite programming solvers.  Method "sos" generates a
   236 certificate that can be pasted into the proof thus avoiding the need
   237 to call an external tool every time the proof is checked.  See
   238 src/HOL/Library/Sum_Of_Squares.
   239 
   240 * New method "linarith" invokes existing linear arithmetic decision
   241 procedure only.
   242 
   243 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   244 
   245 * New Sledgehammer option "Full Types" in Proof General settings menu.
   246 Causes full type information to be output to the ATPs.  This slows
   247 ATPs down considerably but eliminates a source of unsound "proofs"
   248 that fail later.
   249 
   250 * New method "metisFT": A version of metis that uses full type
   251 information in order to avoid failures of proof reconstruction.
   252 
   253 * New evaluator "approximate" approximates an real valued term using
   254 the same method as the approximation method.
   255 
   256 * Method "approximate" now supports arithmetic expressions as
   257 boundaries of intervals and implements interval splitting and Taylor
   258 series expansion.
   259 
   260 * ML antiquotation @{code_datatype} inserts definition of a datatype
   261 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   262 
   263 * New theory SupInf of the supremum and infimum operators for sets of
   264 reals.
   265 
   266 * New theory Probability, which contains a development of measure
   267 theory, eventually leading to Lebesgue integration and probability.
   268 
   269 * Extended Multivariate Analysis to include derivation and Brouwer's
   270 fixpoint theorem.
   271 
   272 * Reorganization of number theory, INCOMPATIBILITY:
   273   - new number theory development for nat and int, in theories Divides
   274     and GCD as well as in new session Number_Theory
   275   - some constants and facts now suffixed with _nat and _int
   276     accordingly
   277   - former session NumberTheory now named Old_Number_Theory, including
   278     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   279   - moved theory Pocklington from src/HOL/Library to
   280     src/HOL/Old_Number_Theory
   281 
   282 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   283 lcm of finite and infinite sets. It is shown that they form a complete
   284 lattice.
   285 
   286 * Class semiring_div requires superclass no_zero_divisors and proof of
   287 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   288 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   289 generalized to class semiring_div, subsuming former theorems
   290 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   291 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   292 INCOMPATIBILITY.
   293 
   294 * Refinements to lattice classes and sets:
   295   - less default intro/elim rules in locale variant, more default
   296     intro/elim rules in class variant: more uniformity
   297   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   298     le_inf_iff
   299   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   300     sup_aci)
   301   - renamed ACI to inf_sup_aci
   302   - new class "boolean_algebra"
   303   - class "complete_lattice" moved to separate theory
   304     "Complete_Lattice"; corresponding constants (and abbreviations)
   305     renamed and with authentic syntax:
   306     Set.Inf ~>    Complete_Lattice.Inf
   307     Set.Sup ~>    Complete_Lattice.Sup
   308     Set.INFI ~>   Complete_Lattice.INFI
   309     Set.SUPR ~>   Complete_Lattice.SUPR
   310     Set.Inter ~>  Complete_Lattice.Inter
   311     Set.Union ~>  Complete_Lattice.Union
   312     Set.INTER ~>  Complete_Lattice.INTER
   313     Set.UNION ~>  Complete_Lattice.UNION
   314   - authentic syntax for
   315     Set.Pow
   316     Set.image
   317   - mere abbreviations:
   318     Set.empty               (for bot)
   319     Set.UNIV                (for top)
   320     Set.inter               (for inf, formerly Set.Int)
   321     Set.union               (for sup, formerly Set.Un)
   322     Complete_Lattice.Inter  (for Inf)
   323     Complete_Lattice.Union  (for Sup)
   324     Complete_Lattice.INTER  (for INFI)
   325     Complete_Lattice.UNION  (for SUPR)
   326   - object-logic definitions as far as appropriate
   327 
   328 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   329 Un_subset_iff are explicitly deleted as default simp rules; then also
   330 their lattice counterparts le_inf_iff and le_sup_iff have to be
   331 deleted to achieve the desired effect.
   332 
   333 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   334 rules by default any longer; the same applies to min_max.inf_absorb1
   335 etc.  INCOMPATIBILITY.
   336 
   337 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   338 pred_set_conv by default.  INCOMPATIBILITY.
   339 
   340 * Power operations on relations and functions are now one dedicated
   341 constant "compow" with infix syntax "^^".  Power operation on
   342 multiplicative monoids retains syntax "^" and is now defined generic
   343 in class power.  INCOMPATIBILITY.
   344 
   345 * Relation composition "R O S" now has a more standard argument order:
   346 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   347 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   348 break, since the O_assoc rule was not rewritten like this.  Fix using
   349 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   350 
   351 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   352 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   353 INCOMPATIBILITY.
   354 
   355 * Most rules produced by inductive and datatype package have mandatory
   356 prefixes.  INCOMPATIBILITY.
   357 
   358 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   359 the attribute of the same name.  Each of the theorems in the list
   360 DERIV_intros assumes composition with an additional function and
   361 matches a variable to the derivative, which has to be solved by the
   362 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   363 of most elementary terms.  Former Maclauren.DERIV_tac and
   364 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   365 INCOMPATIBILITY.
   366 
   367 * Code generator attributes follow the usual underscore convention:
   368     code_unfold     replaces    code unfold
   369     code_post       replaces    code post
   370     etc.
   371   INCOMPATIBILITY.
   372 
   373 * Renamed methods:
   374     sizechange -> size_change
   375     induct_scheme -> induction_schema
   376   INCOMPATIBILITY.
   377 
   378 * Discontinued abbreviation "arbitrary" of constant "undefined".
   379 INCOMPATIBILITY, use "undefined" directly.
   380 
   381 * Renamed theorems:
   382     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   383     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   384     Suc_plus1 -> Suc_eq_plus1
   385     *anti_sym -> *antisym*
   386     vector_less_eq_def -> vector_le_def
   387   INCOMPATIBILITY.
   388 
   389 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   390 INCOMPATIBILITY.
   391 
   392 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   393 INCOMPATIBILITY.
   394 
   395 
   396 *** HOLCF ***
   397 
   398 * Theory Representable defines a class "rep" of domains that are
   399 representable (via an ep-pair) in the universal domain type "udom".
   400 Instances are provided for all type constructors defined in HOLCF.
   401 
   402 * The 'new_domain' command is a purely definitional version of the
   403 domain package, for representable domains.  Syntax is identical to the
   404 old domain package.  The 'new_domain' package also supports indirect
   405 recursion using previously-defined type constructors.  See
   406 src/HOLCF/ex/New_Domain.thy for examples.
   407 
   408 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   409 on the left-hand side of an equation, and then performs
   410 simplification.  Rewriting is done using rules declared with the
   411 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   412 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   413 
   414 * The pattern-match compiler in 'fixrec' can now handle constructors
   415 with HOL function types.  Pattern-match combinators for the Pair
   416 constructor are pre-configured.
   417 
   418 * The 'fixrec' package now produces better fixed-point induction rules
   419 for mutually-recursive definitions:  Induction rules have conclusions
   420 of the form "P foo bar" instead of "P <foo, bar>".
   421 
   422 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   423 been renamed to "below".  The name "below" now replaces "less" in many
   424 theorem names.  (Legacy theorem names using "less" are still supported
   425 as well.)
   426 
   427 * The 'fixrec' package now supports "bottom patterns".  Bottom
   428 patterns can be used to generate strictness rules, or to make
   429 functions more strict (much like the bang-patterns supported by the
   430 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   431 examples.
   432 
   433 
   434 *** ML ***
   435 
   436 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   437 errors and run-time exceptions, including detailed source positions.
   438 
   439 * Structure Name_Space (formerly NameSpace) now manages uniquely
   440 identified entries, with some additional information such as source
   441 position, logical grouping etc.
   442 
   443 * Theory and context data is now introduced by the simplified and
   444 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   445 to be pure, but the old TheoryDataFun for mutable data (with explicit
   446 copy operation) is still available for some time.
   447 
   448 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   449 provides a high-level programming interface to synchronized state
   450 variables with atomic update.  This works via pure function
   451 application within a critical section -- its runtime should be as
   452 short as possible; beware of deadlocks if critical code is nested,
   453 either directly or indirectly via other synchronized variables!
   454 
   455 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   456 wraps raw ML references, explicitly indicating their non-thread-safe
   457 behaviour.  The Isar toplevel keeps this structure open, to
   458 accommodate Proof General as well as quick and dirty interactive
   459 experiments with references.
   460 
   461 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   462 parallel tactical reasoning.
   463 
   464 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   465 are similar to SUBPROOF, but are slightly more flexible: only the
   466 specified parts of the subgoal are imported into the context, and the
   467 body tactic may introduce new subgoals and schematic variables.
   468 
   469 * Old tactical METAHYPS, which does not observe the proof context, has
   470 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   471 or Subgoal.FOCUS etc.
   472 
   473 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   474 functors have their own ML name space there is no point to mark them
   475 separately.)  Minor INCOMPATIBILITY.
   476 
   477 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   478 
   479 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   480 INCOMPATIBILITY.
   481 
   482 * Operations of structure Skip_Proof no longer require quick_and_dirty
   483 mode, which avoids critical setmp.
   484 
   485 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   486 combinators for "args".  INCOMPATIBILITY, need to use simplified
   487 Attrib/Method.setup introduced in Isabelle2009.
   488 
   489 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   490 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   491 last resort.  INCOMPATIBILITY.
   492 
   493 * Display.pretty_thm now requires a proper context (cf. former
   494 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   495 or even Display.pretty_thm_without_context as last resort.
   496 INCOMPATIBILITY.
   497 
   498 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   499 Syntax.pretty_typ/term directly, preferably with proper context
   500 instead of global theory.
   501 
   502 
   503 *** System ***
   504 
   505 * Further fine tuning of parallel proof checking, scales up to 8 cores
   506 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   507 usedir option -q.
   508 
   509 * Support for additional "Isabelle components" via etc/components, see
   510 also the system manual.
   511 
   512 * The isabelle makeall tool now operates on all components with
   513 IsaMakefile, not just hardwired "logics".
   514 
   515 * Removed "compress" option from isabelle-process and isabelle usedir;
   516 this is always enabled.
   517 
   518 * Discontinued support for Poly/ML 4.x versions.
   519 
   520 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   521 on a given logic image.  This requires the lighttpd webserver and is
   522 currently supported on Linux only.
   523 
   524 
   525 
   526 New in Isabelle2009 (April 2009)
   527 --------------------------------
   528 
   529 *** General ***
   530 
   531 * Simplified main Isabelle executables, with less surprises on
   532 case-insensitive file-systems (such as Mac OS).
   533 
   534   - The main Isabelle tool wrapper is now called "isabelle" instead of
   535     "isatool."
   536 
   537   - The former "isabelle" alias for "isabelle-process" has been
   538     removed (should rarely occur to regular users).
   539 
   540   - The former "isabelle-interface" and its alias "Isabelle" have been
   541     removed (interfaces are now regular Isabelle tools).
   542 
   543 Within scripts and make files, the Isabelle environment variables
   544 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   545 respectively.  (The latter are still available as legacy feature.)
   546 
   547 The old isabelle-interface wrapper could react in confusing ways if
   548 the interface was uninstalled or changed otherwise.  Individual
   549 interface tool configuration is now more explicit, see also the
   550 Isabelle system manual.  In particular, Proof General is now available
   551 via "isabelle emacs".
   552 
   553 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   554 purge installed copies of Isabelle executables and re-run "isabelle
   555 install -p ...", or use symlinks.
   556 
   557 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   558 old ~/isabelle, which was slightly non-standard and apt to cause
   559 surprises on case-insensitive file-systems (such as Mac OS).
   560 
   561 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   562 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   563 care is required when using older releases of Isabelle.  Note that
   564 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   565 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   566 
   567 * Proofs of fully specified statements are run in parallel on
   568 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   569 a regular 4-core machine, if the initial heap space is made reasonably
   570 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   571 
   572 * The main reference manuals ("isar-ref", "implementation", and
   573 "system") have been updated and extended.  Formally checked references
   574 as hyperlinks are now available uniformly.
   575 
   576 
   577 *** Pure ***
   578 
   579 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   580 respects.  The most important changes are listed below.  See the
   581 Tutorial on Locales ("locales" manual) for details.
   582 
   583 - In locale expressions, instantiation replaces renaming.  Parameters
   584 must be declared in a for clause.  To aid compatibility with previous
   585 parameter inheritance, in locale declarations, parameters that are not
   586 'touched' (instantiation position "_" or omitted) are implicitly added
   587 with their syntax at the beginning of the for clause.
   588 
   589 - Syntax from abbreviations and definitions in locales is available in
   590 locale expressions and context elements.  The latter is particularly
   591 useful in locale declarations.
   592 
   593 - More flexible mechanisms to qualify names generated by locale
   594 expressions.  Qualifiers (prefixes) may be specified in locale
   595 expressions, and can be marked as mandatory (syntax: "name!:") or
   596 optional (syntax "name?:").  The default depends for plain "name:"
   597 depends on the situation where a locale expression is used: in
   598 commands 'locale' and 'sublocale' prefixes are optional, in
   599 'interpretation' and 'interpret' prefixes are mandatory.  The old
   600 implicit qualifiers derived from the parameter names of a locale are
   601 no longer generated.
   602 
   603 - Command "sublocale l < e" replaces "interpretation l < e".  The
   604 instantiation clause in "interpretation" and "interpret" (square
   605 brackets) is no longer available.  Use locale expressions.
   606 
   607 - When converting proof scripts, mandatory qualifiers in
   608 'interpretation' and 'interpret' should be retained by default, even
   609 if this is an INCOMPATIBILITY compared to former behavior.  In the
   610 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   611 in locale expressions range over a single locale instance only.
   612 
   613 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   614 In existing theorem specifications replace the includes element by the
   615 respective context elements of the included locale, omitting those
   616 that are already present in the theorem specification.  Multiple
   617 assume elements of a locale should be replaced by a single one
   618 involving the locale predicate.  In the proof body, declarations (most
   619 notably theorems) may be regained by interpreting the respective
   620 locales in the proof context as required (command "interpret").
   621 
   622 If using "includes" in replacement of a target solely because the
   623 parameter types in the theorem are not as general as in the target,
   624 consider declaring a new locale with additional type constraints on
   625 the parameters (context element "constrains").
   626 
   627 - Discontinued "locale (open)".  INCOMPATIBILITY.
   628 
   629 - Locale interpretation commands no longer attempt to simplify goal.
   630 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   631 methods intro_locales and unfold_locales to clarify.
   632 
   633 - Locale interpretation commands no longer accept interpretation
   634 attributes.  INCOMPATIBILITY.
   635 
   636 * Class declaration: so-called "base sort" must not be given in import
   637 list any longer, but is inferred from the specification.  Particularly
   638 in HOL, write
   639 
   640     class foo = ...
   641 
   642 instead of
   643 
   644     class foo = type + ...
   645 
   646 * Class target: global versions of theorems stemming do not carry a
   647 parameter prefix any longer.  INCOMPATIBILITY.
   648 
   649 * Class 'instance' command no longer accepts attached definitions.
   650 INCOMPATIBILITY, use proper 'instantiation' target instead.
   651 
   652 * Recovered hiding of consts, which was accidentally broken in
   653 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   654 makes c inaccessible; consider using ``hide (open) const c'' instead.
   655 
   656 * Slightly more coherent Pure syntax, with updated documentation in
   657 isar-ref manual.  Removed locales meta_term_syntax and
   658 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   659 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   660 directly in regular applications.
   661 
   662 * There is a new syntactic category "float_const" for signed decimal
   663 fractions (e.g. 123.45 or -123.45).
   664 
   665 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   666 interface with 'setup' command instead.
   667 
   668 * Command 'local_setup' is similar to 'setup', but operates on a local
   669 theory context.
   670 
   671 * The 'axiomatization' command now only works within a global theory
   672 context.  INCOMPATIBILITY.
   673 
   674 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   675 hypotheses.  Sorts required in the course of reasoning need to be
   676 covered by the constraints in the initial statement, completed by the
   677 type instance information of the background theory.  Non-trivial sort
   678 hypotheses, which rarely occur in practice, may be specified via
   679 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   680 
   681   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   682 
   683 The result contains an implicit sort hypotheses as before --
   684 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   685 normalization.
   686 
   687 * Generalized Isar history, with support for linear undo, direct state
   688 addressing etc.
   689 
   690 * Changed defaults for unify configuration options:
   691 
   692   unify_trace_bound = 50 (formerly 25)
   693   unify_search_bound = 60 (formerly 30)
   694 
   695 * Different bookkeeping for code equations (INCOMPATIBILITY):
   696 
   697   a) On theory merge, the last set of code equations for a particular
   698      constant is taken (in accordance with the policy applied by other
   699      parts of the code generator framework).
   700 
   701   b) Code equations stemming from explicit declarations (e.g. code
   702      attribute) gain priority over default code equations stemming
   703      from definition, primrec, fun etc.
   704 
   705 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   706 
   707 * Unified theorem tables for both code generators.  Thus [code
   708 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   709 
   710 * Command 'find_consts' searches for constants based on type and name
   711 patterns, e.g.
   712 
   713     find_consts "_ => bool"
   714 
   715 By default, matching is against subtypes, but it may be restricted to
   716 the whole type.  Searching by name is possible.  Multiple queries are
   717 conjunctive and queries may be negated by prefixing them with a
   718 hyphen:
   719 
   720     find_consts strict: "_ => bool" name: "Int" -"int => int"
   721 
   722 * New 'find_theorems' criterion "solves" matches theorems that
   723 directly solve the current goal (modulo higher-order unification).
   724 
   725 * Auto solve feature for main theorem statements: whenever a new goal
   726 is stated, "find_theorems solves" is called; any theorems that could
   727 solve the lemma directly are listed as part of the goal state.
   728 Cf. associated options in Proof General Isabelle settings menu,
   729 enabled by default, with reasonable timeout for pathological cases of
   730 higher-order unification.
   731 
   732 
   733 *** Document preparation ***
   734 
   735 * Antiquotation @{lemma} now imitates a regular terminal proof,
   736 demanding keyword 'by' and supporting the full method expression
   737 syntax just like the Isar command 'by'.
   738 
   739 
   740 *** HOL ***
   741 
   742 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   743 points Main and Complex_Main remain as before.
   744 
   745 * Logic image HOL-Plain provides a minimal HOL with the most important
   746 tools available (inductive, datatype, primrec, ...).  This facilitates
   747 experimentation and tool development.  Note that user applications
   748 (and library theories) should never refer to anything below theory
   749 Main, as before.
   750 
   751 * Logic image HOL-Main stops at theory Main, and thus facilitates
   752 experimentation due to shorter build times.
   753 
   754 * Logic image HOL-NSA contains theories of nonstandard analysis which
   755 were previously part of former HOL-Complex.  Entry point Hyperreal
   756 remains valid, but theories formerly using Complex_Main should now use
   757 new entry point Hypercomplex.
   758 
   759 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   760 Posix processes.  Avoids potentially expensive forking of the ML
   761 process.  New thread-based implementation also works on non-Unix
   762 platforms (Cygwin).  Provers are no longer hardwired, but defined
   763 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   764 commands are covered in the isar-ref manual.
   765 
   766 * Wrapper scripts for remote SystemOnTPTP service allows to use
   767 sledgehammer without local ATP installation (Vampire etc.). Other
   768 provers may be included via suitable ML wrappers, see also
   769 src/HOL/ATP_Linkup.thy.
   770 
   771 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   772 menu.
   773 
   774 * The metis method no longer fails because the theorem is too trivial
   775 (contains the empty clause).
   776 
   777 * The metis method now fails in the usual manner, rather than raising
   778 an exception, if it determines that it cannot prove the theorem.
   779 
   780 * Method "coherent" implements a prover for coherent logic (see also
   781 src/Tools/coherent.ML).
   782 
   783 * Constants "undefined" and "default" replace "arbitrary".  Usually
   784 "undefined" is the right choice to replace "arbitrary", though
   785 logically there is no difference.  INCOMPATIBILITY.
   786 
   787 * Command "value" now integrates different evaluation mechanisms.  The
   788 result of the first successful evaluation mechanism is printed.  In
   789 square brackets a particular named evaluation mechanisms may be
   790 specified (currently, [SML], [code] or [nbe]).  See further
   791 src/HOL/ex/Eval_Examples.thy.
   792 
   793 * Normalization by evaluation now allows non-leftlinear equations.
   794 Declare with attribute [code nbe].
   795 
   796 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   797 as the structured Isar versions "cases" and "induct", cf. the
   798 corresponding "cases" and "induct" attributes.  Mutual induction rules
   799 are now presented as a list of individual projections
   800 (e.g. foo_bar.inducts for types foo and bar); the old format with
   801 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   802 rare situations a different rule is selected --- notably nested tuple
   803 elimination instead of former prod.exhaust: use explicit (case_tac t
   804 rule: prod.exhaust) here.
   805 
   806 * Attributes "cases", "induct", "coinduct" support "del" option.
   807 
   808 * Removed fact "case_split_thm", which duplicates "case_split".
   809 
   810 * The option datatype has been moved to a new theory Option.  Renamed
   811 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   812 
   813 * New predicate "strict_mono" classifies strict functions on partial
   814 orders.  With strict functions on linear orders, reasoning about
   815 (in)equalities is facilitated by theorems "strict_mono_eq",
   816 "strict_mono_less_eq" and "strict_mono_less".
   817 
   818 * Some set operations are now proper qualified constants with
   819 authentic syntax.  INCOMPATIBILITY:
   820 
   821     op Int ~>   Set.Int
   822     op Un ~>    Set.Un
   823     INTER ~>    Set.INTER
   824     UNION ~>    Set.UNION
   825     Inter ~>    Set.Inter
   826     Union ~>    Set.Union
   827     {} ~>       Set.empty
   828     UNIV ~>     Set.UNIV
   829 
   830 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   831 theory Set.
   832 
   833 * Auxiliary class "itself" has disappeared -- classes without any
   834 parameter are treated as expected by the 'class' command.
   835 
   836 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   837 
   838 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   839 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   840 
   841 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   842 method "approximation".  It proves formulas on real values by using
   843 interval arithmetic.  In the formulas are also the transcendental
   844 functions sin, cos, tan, atan, ln, exp and the constant pi are
   845 allowed. For examples see
   846 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   847 
   848 * Theory "Reflection" now resides in HOL/Library.
   849 
   850 * Entry point to Word library now simply named "Word".
   851 INCOMPATIBILITY.
   852 
   853 * Made source layout more coherent with logical distribution
   854 structure:
   855 
   856     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   857     src/HOL/Library/Code_Message.thy ~> src/HOL/
   858     src/HOL/Library/GCD.thy ~> src/HOL/
   859     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   860     src/HOL/Library/Parity.thy ~> src/HOL/
   861     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   862     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   863     src/HOL/Real/Lubs.thy ~> src/HOL/
   864     src/HOL/Real/PReal.thy ~> src/HOL/
   865     src/HOL/Real/Rational.thy ~> src/HOL/
   866     src/HOL/Real/RComplete.thy ~> src/HOL/
   867     src/HOL/Real/RealDef.thy ~> src/HOL/
   868     src/HOL/Real/RealPow.thy ~> src/HOL/
   869     src/HOL/Real/Real.thy ~> src/HOL/
   870     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   871     src/HOL/Complex/Complex.thy ~> src/HOL/
   872     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   873     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   874     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   875     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   876     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   877     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   878     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   879     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   880     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   881     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   882     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   883     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   884     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   885     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   886     src/HOL/Real/Float ~> src/HOL/Library/
   887     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   888     src/HOL/Real/RealVector.thy ~> src/HOL/
   889 
   890     src/HOL/arith_data.ML ~> src/HOL/Tools
   891     src/HOL/hologic.ML ~> src/HOL/Tools
   892     src/HOL/simpdata.ML ~> src/HOL/Tools
   893     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   894     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   895     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   896     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   897     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   898     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   899     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   900 
   901     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   902     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   903     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   904     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   905     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   906     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   907 
   908 * If methods "eval" and "evaluation" encounter a structured proof
   909 state with !!/==>, only the conclusion is evaluated to True (if
   910 possible), avoiding strange error messages.
   911 
   912 * Method "sizechange" automates termination proofs using (a
   913 modification of) the size-change principle.  Requires SAT solver.  See
   914 src/HOL/ex/Termination.thy for examples.
   915 
   916 * Simplifier: simproc for let expressions now unfolds if bound
   917 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   918 
   919 * Method "arith": Linear arithmetic now ignores all inequalities when
   920 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   921 
   922 * New attribute "arith" for facts that should always be used
   923 automatically by arithmetic. It is intended to be used locally in
   924 proofs, e.g.
   925 
   926   assumes [arith]: "x > 0"
   927 
   928 Global usage is discouraged because of possible performance impact.
   929 
   930 * New classes "top" and "bot" with corresponding operations "top" and
   931 "bot" in theory Orderings; instantiation of class "complete_lattice"
   932 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   933 
   934 * Changed definition lemma "less_fun_def" in order to provide an
   935 instance for preorders on functions; use lemma "less_le" instead.
   936 INCOMPATIBILITY.
   937 
   938 * Theory Orderings: class "wellorder" moved here, with explicit
   939 induction rule "less_induct" as assumption.  For instantiation of
   940 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   941 INCOMPATIBILITY.
   942 
   943 * Theory Orderings: added class "preorder" as superclass of "order".
   944 INCOMPATIBILITY: Instantiation proofs for order, linorder
   945 etc. slightly changed.  Some theorems named order_class.* now named
   946 preorder_class.*.
   947 
   948 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   949 "diag" to "Id_on".
   950 
   951 * Theory Finite_Set: added a new fold combinator of type
   952 
   953   ('a => 'b => 'b) => 'b => 'a set => 'b
   954 
   955 Occasionally this is more convenient than the old fold combinator
   956 which is now defined in terms of the new one and renamed to
   957 fold_image.
   958 
   959 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   960 and "ring_simps" have been replaced by "algebra_simps" (which can be
   961 extended with further lemmas!).  At the moment both still exist but
   962 the former will disappear at some point.
   963 
   964 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   965 class recpower.  Type-specific simp rules for various recpower types
   966 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   967 
   968 rat_power_0    -> power_0
   969 rat_power_Suc  -> power_Suc
   970 realpow_0      -> power_0
   971 realpow_Suc    -> power_Suc
   972 complexpow_0   -> power_0
   973 complexpow_Suc -> power_Suc
   974 power_poly_0   -> power_0
   975 power_poly_Suc -> power_Suc
   976 
   977 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   978 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   979 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   980 of lemmas from Divides has been generalized from nat to class
   981 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   982 renames resulting from duplicate elimination:
   983 
   984     dvd_def_mod ~>          dvd_eq_mod_eq_0
   985     zero_dvd_iff ~>         dvd_0_left_iff
   986     dvd_0 ~>                dvd_0_right
   987     DIVISION_BY_ZERO_DIV ~> div_by_0
   988     DIVISION_BY_ZERO_MOD ~> mod_by_0
   989     mult_div ~>             div_mult_self2_is_id
   990     mult_mod ~>             mod_mult_self2_is_0
   991 
   992 * Theory IntDiv: removed many lemmas that are instances of class-based
   993 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   994 rename old lemmas as follows:
   995 
   996 dvd_diff               -> nat_dvd_diff
   997 dvd_zminus_iff         -> dvd_minus_iff
   998 mod_add1_eq            -> mod_add_eq
   999 mod_mult1_eq           -> mod_mult_right_eq
  1000 mod_mult1_eq'          -> mod_mult_left_eq
  1001 mod_mult_distrib_mod   -> mod_mult_eq
  1002 nat_mod_add_left_eq    -> mod_add_left_eq
  1003 nat_mod_add_right_eq   -> mod_add_right_eq
  1004 nat_mod_div_trivial    -> mod_div_trivial
  1005 nat_mod_mod_trivial    -> mod_mod_trivial
  1006 zdiv_zadd_self1        -> div_add_self1
  1007 zdiv_zadd_self2        -> div_add_self2
  1008 zdiv_zmult_self1       -> div_mult_self2_is_id
  1009 zdiv_zmult_self2       -> div_mult_self1_is_id
  1010 zdvd_triv_left         -> dvd_triv_left
  1011 zdvd_triv_right        -> dvd_triv_right
  1012 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1013 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1014 zmod_zadd_left_eq      -> mod_add_left_eq
  1015 zmod_zadd_right_eq     -> mod_add_right_eq
  1016 zmod_zadd_self1        -> mod_add_self1
  1017 zmod_zadd_self2        -> mod_add_self2
  1018 zmod_zadd1_eq          -> mod_add_eq
  1019 zmod_zdiff1_eq         -> mod_diff_eq
  1020 zmod_zdvd_zmod         -> mod_mod_cancel
  1021 zmod_zmod_cancel       -> mod_mod_cancel
  1022 zmod_zmult_self1       -> mod_mult_self2_is_0
  1023 zmod_zmult_self2       -> mod_mult_self1_is_0
  1024 zmod_1                 -> mod_by_1
  1025 zdiv_1                 -> div_by_1
  1026 zdvd_abs1              -> abs_dvd_iff
  1027 zdvd_abs2              -> dvd_abs_iff
  1028 zdvd_refl              -> dvd_refl
  1029 zdvd_trans             -> dvd_trans
  1030 zdvd_zadd              -> dvd_add
  1031 zdvd_zdiff             -> dvd_diff
  1032 zdvd_zminus_iff        -> dvd_minus_iff
  1033 zdvd_zminus2_iff       -> minus_dvd_iff
  1034 zdvd_zmultD            -> dvd_mult_right
  1035 zdvd_zmultD2           -> dvd_mult_left
  1036 zdvd_zmult_mono        -> mult_dvd_mono
  1037 zdvd_0_right           -> dvd_0_right
  1038 zdvd_0_left            -> dvd_0_left_iff
  1039 zdvd_1_left            -> one_dvd
  1040 zminus_dvd_iff         -> minus_dvd_iff
  1041 
  1042 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1043 
  1044 * The real numbers offer decimal input syntax: 12.34 is translated
  1045 into 1234/10^2. This translation is not reversed upon output.
  1046 
  1047 * Theory Library/Polynomial defines an abstract type 'a poly of
  1048 univariate polynomials with coefficients of type 'a.  In addition to
  1049 the standard ring operations, it also supports div and mod.  Code
  1050 generation is also supported, using list-style constructors.
  1051 
  1052 * Theory Library/Inner_Product defines a class of real_inner for real
  1053 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1054 => real.  Class real_inner is a subclass of real_normed_vector from
  1055 theory RealVector.
  1056 
  1057 * Theory Library/Product_Vector provides instances for the product
  1058 type 'a * 'b of several classes from RealVector and Inner_Product.
  1059 Definitions of addition, subtraction, scalar multiplication, norms,
  1060 and inner products are included.
  1061 
  1062 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1063 addition to the field operations, numerals and case syntax are also
  1064 supported.
  1065 
  1066 * Theory Library/Diagonalize provides constructive version of Cantor's
  1067 first diagonalization argument.
  1068 
  1069 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1070 zlcm (for int); carried together from various gcd/lcm developements in
  1071 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1072 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1073 may recover tupled syntax as follows:
  1074 
  1075     hide (open) const gcd
  1076     abbreviation gcd where
  1077       "gcd == (%(a, b). GCD.gcd a b)"
  1078     notation (output)
  1079       GCD.gcd ("gcd '(_, _')")
  1080 
  1081 The same works for lcm, zgcd, zlcm.
  1082 
  1083 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1084 instantiations for algebraic structures.  Removed some duplicate
  1085 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1086 
  1087 * ML antiquotation @{code} takes a constant as argument and generates
  1088 corresponding code in background and inserts name of the corresponding
  1089 resulting ML value/function/datatype constructor binding in place.
  1090 All occurrences of @{code} with a single ML block are generated
  1091 simultaneously.  Provides a generic and safe interface for
  1092 instrumentalizing code generation.  See
  1093 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1094 In future you ought to refrain from ad-hoc compiling generated SML
  1095 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1096 cannot refer to constants for which user-defined serializations are
  1097 set.  Refer to the corresponding ML counterpart directly in that
  1098 cases.
  1099 
  1100 * Command 'rep_datatype': instead of theorem names the command now
  1101 takes a list of terms denoting the constructors of the type to be
  1102 represented as datatype.  The characteristic theorems have to be
  1103 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1104 have disappeared in favour of existing ones:
  1105 
  1106     unit_induct                 ~> unit.induct
  1107     prod_induct                 ~> prod.induct
  1108     sum_induct                  ~> sum.induct
  1109     Suc_Suc_eq                  ~> nat.inject
  1110     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1111 
  1112 
  1113 *** HOL-Algebra ***
  1114 
  1115 * New locales for orders and lattices where the equivalence relation
  1116 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1117 locales use a record structure with field eq for the equivalence.
  1118 
  1119 * New theory of factorial domains.
  1120 
  1121 * Units_l_inv and Units_r_inv are now simp rules by default.
  1122 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1123 and/or r_inv will now also require deletion of these lemmas.
  1124 
  1125 * Renamed the following theorems, INCOMPATIBILITY:
  1126 
  1127 UpperD ~> Upper_memD
  1128 LowerD ~> Lower_memD
  1129 least_carrier ~> least_closed
  1130 greatest_carrier ~> greatest_closed
  1131 greatest_Lower_above ~> greatest_Lower_below
  1132 one_zero ~> carrier_one_zero
  1133 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1134 
  1135 
  1136 *** HOL-Nominal ***
  1137 
  1138 * Nominal datatypes can now contain type-variables.
  1139 
  1140 * Commands 'nominal_inductive' and 'equivariance' work with local
  1141 theory targets.
  1142 
  1143 * Nominal primrec can now works with local theory targets and its
  1144 specification syntax now conforms to the general format as seen in
  1145 'inductive' etc.
  1146 
  1147 * Method "perm_simp" honours the standard simplifier attributes
  1148 (no_asm), (no_asm_use) etc.
  1149 
  1150 * The new predicate #* is defined like freshness, except that on the
  1151 left hand side can be a set or list of atoms.
  1152 
  1153 * Experimental command 'nominal_inductive2' derives strong induction
  1154 principles for inductive definitions.  In contrast to
  1155 'nominal_inductive', which can only deal with a fixed number of
  1156 binders, it can deal with arbitrary expressions standing for sets of
  1157 atoms to be avoided.  The only inductive definition we have at the
  1158 moment that needs this generalisation is the typing rule for Lets in
  1159 the algorithm W:
  1160 
  1161  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1162  -----------------------------------------------------------------
  1163          Gamma |- Let x be t1 in t2 : T2
  1164 
  1165 In this rule one wants to avoid all the binders that are introduced by
  1166 "close Gamma T1".  We are looking for other examples where this
  1167 feature might be useful.  Please let us know.
  1168 
  1169 
  1170 *** HOLCF ***
  1171 
  1172 * Reimplemented the simplification procedure for proving continuity
  1173 subgoals.  The new simproc is extensible; users can declare additional
  1174 continuity introduction rules with the attribute [cont2cont].
  1175 
  1176 * The continuity simproc now uses a different introduction rule for
  1177 solving continuity subgoals on terms with lambda abstractions.  In
  1178 some rare cases the new simproc may fail to solve subgoals that the
  1179 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1180 Potential INCOMPATIBILITY.
  1181 
  1182 * Command 'fixrec': specification syntax now conforms to the general
  1183 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1184 examples.  INCOMPATIBILITY.
  1185 
  1186 
  1187 *** ZF ***
  1188 
  1189 * Proof of Zorn's Lemma for partial orders.
  1190 
  1191 
  1192 *** ML ***
  1193 
  1194 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1195 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1196 depends on multithreading, so timouts will not work before Poly/ML
  1197 5.2.1!
  1198 
  1199 * High-level support for concurrent ML programming, see
  1200 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1201 particularly convenient to organize independent functional
  1202 computations.  The concept of "synchronized variables" provides a
  1203 higher-order interface for components with shared state, avoiding the
  1204 delicate details of mutexes and condition variables.  (Requires
  1205 Poly/ML 5.2.1 or later.)
  1206 
  1207 * ML bindings produced via Isar commands are stored within the Isar
  1208 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1209 become thread-safe and work with undo as expected (concerning
  1210 top-level bindings, not side-effects on global references).
  1211 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1212 compiler at runtime; really global bindings need to be given outside a
  1213 theory.  (Requires Poly/ML 5.2 or later.)
  1214 
  1215 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1216 context.  Top-level ML bindings are stored within the proof context in
  1217 a purely sequential fashion, disregarding the nested proof structure.
  1218 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1219 proof.  (Requires Poly/ML 5.2 or later.)
  1220 
  1221 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1222 and Method.setup, as well as Isar commands 'attribute_setup' and
  1223 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1224 existing code accordingly, or use plain 'setup' together with old
  1225 Method.add_method.
  1226 
  1227 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1228 to 'a -> thm, while results are always tagged with an authentic oracle
  1229 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1230 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1231 accordingly.  Note that extra performance may be gained by producing
  1232 the cterm carefully, avoiding slow Thm.cterm_of.
  1233 
  1234 * Simplified interface for defining document antiquotations via
  1235 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1236 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1237 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1238 examples.
  1239 
  1240 * More systematic treatment of long names, abstract name bindings, and
  1241 name space operations.  Basic operations on qualified names have been
  1242 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1243 Long_Name.append.  Old type bstring has been mostly replaced by
  1244 abstract type binding (see structure Binding), which supports precise
  1245 qualification by packages and local theory targets, as well as proper
  1246 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1247 bstring values into Binding.name, or better pass through abstract
  1248 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1249 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1250 
  1251 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1252 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1253 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1254 
  1255 * Disposed old type and term read functions (Sign.read_def_typ,
  1256 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1257 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1258 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1259 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1260 resort for legacy applications.
  1261 
  1262 * Disposed old declarations, tactics, tactic combinators that refer to
  1263 the simpset or claset of an implicit theory (such as Addsimps,
  1264 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1265 embedded ML text, or local_simpset_of with a proper context passed as
  1266 explicit runtime argument.
  1267 
  1268 * Rules and tactics that read instantiations (read_instantiate,
  1269 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1270 context, which is required for parsing and type-checking.  Moreover,
  1271 the variables are specified as plain indexnames, not string encodings
  1272 thereof.  INCOMPATIBILITY.
  1273 
  1274 * Generic Toplevel.add_hook interface allows to analyze the result of
  1275 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1276 for theorem dependency output of transactions resulting in a new
  1277 theory state.
  1278 
  1279 * ML antiquotations: block-structured compilation context indicated by
  1280 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1281 
  1282   @{binding name}                         - basic name binding
  1283   @{let ?pat = term}                      - term abbreviation (HO matching)
  1284   @{note name = fact}                     - fact abbreviation
  1285   @{thm fact}                             - singleton fact (with attributes)
  1286   @{thms fact}                            - general fact (with attributes)
  1287   @{lemma prop by method}                 - singleton goal
  1288   @{lemma prop by meth1 meth2}            - singleton goal
  1289   @{lemma prop1 ... propN by method}      - general goal
  1290   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1291   @{lemma (open) ...}                     - open derivation
  1292 
  1293 
  1294 *** System ***
  1295 
  1296 * The Isabelle "emacs" tool provides a specific interface to invoke
  1297 Proof General / Emacs, with more explicit failure if that is not
  1298 installed (the old isabelle-interface script silently falls back on
  1299 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1300 installation location of the Proof General distribution.
  1301 
  1302 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1303 the Isabelle process into a JVM/Scala application.  See
  1304 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1305 process wrapper has been discontinued.)
  1306 
  1307 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1308 
  1309 * Various status messages (with exact source position information) are
  1310 emitted, if proper markup print mode is enabled.  This allows
  1311 user-interface components to provide detailed feedback on internal
  1312 prover operations.
  1313 
  1314 
  1315 
  1316 New in Isabelle2008 (June 2008)
  1317 -------------------------------
  1318 
  1319 *** General ***
  1320 
  1321 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1322 and updated, with formally checked references as hyperlinks.
  1323 
  1324 * Theory loader: use_thy (and similar operations) no longer set the
  1325 implicit ML context, which was occasionally hard to predict and in
  1326 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1327 provides a proper context already.
  1328 
  1329 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1330 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1331 'use' within a theory file will do the job.
  1332 
  1333 * Name space merge now observes canonical order, i.e. the second space
  1334 is inserted into the first one, while existing entries in the first
  1335 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1336 swap theory imports.
  1337 
  1338 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1339 INCOMPATIBILITY in identifier syntax etc.
  1340 
  1341 * Outer syntax: string tokens no longer admit escaped white space,
  1342 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1343 white space without escapes.
  1344 
  1345 * Outer syntax: string tokens may contain arbitrary character codes
  1346 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1347 "foo_bar".
  1348 
  1349 
  1350 *** Pure ***
  1351 
  1352 * Context-dependent token translations.  Default setup reverts locally
  1353 fixed variables, and adds hilite markup for undeclared frees.
  1354 
  1355 * Unused theorems can be found using the new command 'unused_thms'.
  1356 There are three ways of invoking it:
  1357 
  1358 (1) unused_thms
  1359      Only finds unused theorems in the current theory.
  1360 
  1361 (2) unused_thms thy_1 ... thy_n -
  1362      Finds unused theorems in the current theory and all of its ancestors,
  1363      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1364 
  1365 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1366      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1367      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1368      their ancestors.
  1369 
  1370 In order to increase the readability of the list produced by
  1371 unused_thms, theorems that have been created by a particular instance
  1372 of a theory command such as 'inductive' or 'function' are considered
  1373 to belong to the same "group", meaning that if at least one theorem in
  1374 this group is used, the other theorems in the same group are no longer
  1375 reported as unused.  Moreover, if all theorems in the group are
  1376 unused, only one theorem in the group is displayed.
  1377 
  1378 Note that proof objects have to be switched on in order for
  1379 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1380 usually the case when using Proof General with the default settings).
  1381 
  1382 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1383 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1384 duplicate fact bindings, or even accidental fact duplications.  Note
  1385 that tools may maintain dynamically scoped facts systematically, using
  1386 PureThy.add_thms_dynamic.
  1387 
  1388 * Command 'hide' now allows to hide from "fact" name space as well.
  1389 
  1390 * Eliminated destructive theorem database, simpset, claset, and
  1391 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1392 update of theories within ML code.
  1393 
  1394 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1395 INCOMPATIBILITY, object-logics depending on former Pure require
  1396 additional setup PureThy.old_appl_syntax_setup; object-logics
  1397 depending on former CPure need to refer to Pure.
  1398 
  1399 * Commands 'use' and 'ML' are now purely functional, operating on
  1400 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1401 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1402 INCOMPATIBILITY.
  1403 
  1404 * Command 'setup': discontinued implicit version with ML reference.
  1405 
  1406 * Instantiation target allows for simultaneous specification of class
  1407 instance operations together with an instantiation proof.
  1408 Type-checking phase allows to refer to class operations uniformly.
  1409 See src/HOL/Complex/Complex.thy for an Isar example and
  1410 src/HOL/Library/Eval.thy for an ML example.
  1411 
  1412 * Indexing of literal facts: be more serious about including only
  1413 facts from the visible specification/proof context, but not the
  1414 background context (locale etc.).  Affects `prop` notation and method
  1415 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1416 situations.
  1417 
  1418 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1419 "(open)" option, which used to expose internal bound variables to the
  1420 proof text.
  1421 
  1422 * Isar statements: removed obsolete case "rule_context".
  1423 INCOMPATIBILITY, better use explicit fixes/assumes.
  1424 
  1425 * Locale proofs: default proof step now includes 'unfold_locales';
  1426 hence 'proof' without argument may be used to unfold locale
  1427 predicates.
  1428 
  1429 
  1430 *** Document preparation ***
  1431 
  1432 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1433 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1434 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1435 spot); renamed link color from "darkblue" to "linkcolor" (default
  1436 value unchanged, can be redefined via \definecolor); no longer sets
  1437 "a4paper" option (unnecessary or even intrusive).
  1438 
  1439 * Antiquotation @{lemma A method} proves proposition A by the given
  1440 method (either a method name or a method name plus (optional) method
  1441 arguments in parentheses) and prints A just like @{prop A}.
  1442 
  1443 
  1444 *** HOL ***
  1445 
  1446 * New primrec package.  Specification syntax conforms in style to
  1447 definition/function/....  No separate induction rule is provided.  The
  1448 "primrec" command distinguishes old-style and new-style specifications
  1449 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1450 When adjusting theories, beware: constants stemming from new-style
  1451 primrec specifications have authentic syntax.
  1452 
  1453 * Metis prover is now an order of magnitude faster, and also works
  1454 with multithreading.
  1455 
  1456 * Metis: the maximum number of clauses that can be produced from a
  1457 theorem is now given by the attribute max_clauses.  Theorems that
  1458 exceed this number are ignored, with a warning printed.
  1459 
  1460 * Sledgehammer no longer produces structured proofs by default. To
  1461 enable, declare [[sledgehammer_full = true]].  Attributes
  1462 reconstruction_modulus, reconstruction_sorts renamed
  1463 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1464 
  1465 * Method "induct_scheme" derives user-specified induction rules
  1466 from well-founded induction and completeness of patterns. This factors
  1467 out some operations that are done internally by the function package
  1468 and makes them available separately.  See
  1469 src/HOL/ex/Induction_Scheme.thy for examples.
  1470 
  1471 * More flexible generation of measure functions for termination
  1472 proofs: Measure functions can be declared by proving a rule of the
  1473 form "is_measure f" and giving it the [measure_function] attribute.
  1474 The "is_measure" predicate is logically meaningless (always true), and
  1475 just guides the heuristic.  To find suitable measure functions, the
  1476 termination prover sets up the goal "is_measure ?f" of the appropriate
  1477 type and generates all solutions by prolog-style backwards proof using
  1478 the declared rules.
  1479 
  1480 This setup also deals with rules like 
  1481 
  1482   "is_measure f ==> is_measure (list_size f)"
  1483 
  1484 which accommodates nested datatypes that recurse through lists.
  1485 Similar rules are predeclared for products and option types.
  1486 
  1487 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1488 
  1489   INCOMPATIBILITIES:
  1490 
  1491   - Definitions of overloaded constants on sets have to be replaced by
  1492     definitions on => and bool.
  1493 
  1494   - Some definitions of overloaded operators on sets can now be proved
  1495     using the definitions of the operators on => and bool.  Therefore,
  1496     the following theorems have been renamed:
  1497 
  1498       subset_def   -> subset_eq
  1499       psubset_def  -> psubset_eq
  1500       set_diff_def -> set_diff_eq
  1501       Compl_def    -> Compl_eq
  1502       Sup_set_def  -> Sup_set_eq
  1503       Inf_set_def  -> Inf_set_eq
  1504       sup_set_def  -> sup_set_eq
  1505       inf_set_def  -> inf_set_eq
  1506 
  1507   - Due to the incompleteness of the HO unification algorithm, some
  1508     rules such as subst may require manual instantiation, if some of
  1509     the unknowns in the rule is a set.
  1510 
  1511   - Higher order unification and forward proofs:
  1512     The proof pattern
  1513 
  1514       have "P (S::'a set)" <...>
  1515       then have "EX S. P S" ..
  1516 
  1517     no longer works (due to the incompleteness of the HO unification
  1518     algorithm) and must be replaced by the pattern
  1519 
  1520       have "EX S. P S"
  1521       proof
  1522         show "P S" <...>
  1523       qed
  1524 
  1525   - Calculational reasoning with subst (or similar rules):
  1526     The proof pattern
  1527 
  1528       have "P (S::'a set)" <...>
  1529       also have "S = T" <...>
  1530       finally have "P T" .
  1531 
  1532     no longer works (for similar reasons as the previous example) and
  1533     must be replaced by something like
  1534 
  1535       have "P (S::'a set)" <...>
  1536       moreover have "S = T" <...>
  1537       ultimately have "P T" by simp
  1538 
  1539   - Tactics or packages written in ML code:
  1540     Code performing pattern matching on types via
  1541 
  1542       Type ("set", [T]) => ...
  1543 
  1544     must be rewritten. Moreover, functions like strip_type or
  1545     binder_types no longer return the right value when applied to a
  1546     type of the form
  1547 
  1548       T1 => ... => Tn => U => bool
  1549 
  1550     rather than
  1551 
  1552       T1 => ... => Tn => U set
  1553 
  1554 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1555 Wellfounded_Relations to theory Wellfounded.
  1556 
  1557 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1558 
  1559 * Class finite no longer treats UNIV as class parameter.  Use class
  1560 enum from theory Library/Enum instead to achieve a similar effect.
  1561 INCOMPATIBILITY.
  1562 
  1563 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1564 and "Cons".  INCOMPATIBILITY.
  1565 
  1566 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1567 Potential INCOMPATIBILITY.
  1568 
  1569 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1570 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1571 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1572 
  1573 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1574 the same name in theory Orderings:
  1575 
  1576   less_trans
  1577   less_linear
  1578   le_imp_less_or_eq
  1579   le_less_trans
  1580   less_le_trans
  1581   less_not_sym
  1582   less_asym
  1583 
  1584 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1585 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1586 and different variable names.
  1587 
  1588 * Library/Option_ord.thy: Canonical order on option type.
  1589 
  1590 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1591 finite maps.
  1592 
  1593 * Library/Countable.thy: Type class for countable types.
  1594 
  1595 * Theory Int: The representation of numerals has changed.  The infix
  1596 operator BIT and the bit datatype with constructors B0 and B1 have
  1597 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1598 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1599 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1600 accordingly.
  1601 
  1602 * Theory Nat: definition of <= and < on natural numbers no longer
  1603 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1604 le_def and less_def have disappeared.  Consider lemmas not_less
  1605 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1606 
  1607 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1608 (whose purpose mainly is for various fold_set functionals) have been
  1609 abandoned in favor of the existing algebraic classes
  1610 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1611 lower_semilattice (resp. upper_semilattice) and linorder.
  1612 INCOMPATIBILITY.
  1613 
  1614 * Theory Transitive_Closure: induct and cases rules now declare proper
  1615 case_names ("base" and "step").  INCOMPATIBILITY.
  1616 
  1617 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1618 lattices.  The form set-specific version is available as
  1619 Inductive.lfp_ordinal_induct_set.
  1620 
  1621 * Renamed theorems "power.simps" to "power_int.simps".
  1622 INCOMPATIBILITY.
  1623 
  1624 * Class semiring_div provides basic abstract properties of semirings
  1625 with division and modulo operations.  Subsumes former class dvd_mod.
  1626 
  1627 * Merged theories IntDef, Numeral and IntArith into unified theory
  1628 Int.  INCOMPATIBILITY.
  1629 
  1630 * Theory Library/Code_Index: type "index" now represents natural
  1631 numbers rather than integers.  INCOMPATIBILITY.
  1632 
  1633 * New class "uminus" with operation "uminus" (split of from class
  1634 "minus" which now only has operation "minus", binary).
  1635 INCOMPATIBILITY.
  1636 
  1637 * Constants "card", "internal_split", "option_map" now with authentic
  1638 syntax.  INCOMPATIBILITY.
  1639 
  1640 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1641 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1642 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1643 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1644 Sup_set_def, le_def, less_def, option_map_def now with object
  1645 equality.  INCOMPATIBILITY.
  1646 
  1647 * Records. Removed K_record, and replaced it by pure lambda term
  1648 %x. c. The simplifier setup is now more robust against eta expansion.
  1649 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1650 
  1651 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1652 
  1653 * Library/ListVector: new theory of arithmetic vector operations.
  1654 
  1655 * Library/Order_Relation: new theory of various orderings as sets of
  1656 pairs.  Defines preorders, partial orders, linear orders and
  1657 well-orders on sets and on types.
  1658 
  1659 
  1660 *** ZF ***
  1661 
  1662 * Renamed some theories to allow to loading both ZF and HOL in the
  1663 same session:
  1664 
  1665   Datatype  -> Datatype_ZF
  1666   Inductive -> Inductive_ZF
  1667   Int       -> Int_ZF
  1668   IntDiv    -> IntDiv_ZF
  1669   Nat       -> Nat_ZF
  1670   List      -> List_ZF
  1671   Main      -> Main_ZF
  1672 
  1673 INCOMPATIBILITY: ZF theories that import individual theories below
  1674 Main might need to be adapted.  Regular theory Main is still
  1675 available, as trivial extension of Main_ZF.
  1676 
  1677 
  1678 *** ML ***
  1679 
  1680 * ML within Isar: antiquotation @{const name} or @{const
  1681 name(typargs)} produces statically-checked Const term.
  1682 
  1683 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1684 (of the same name).  Removed obsolete print command.
  1685 
  1686 * Removed obsolete "use_legacy_bindings" function.
  1687 
  1688 * The ``print mode'' is now a thread-local value derived from a global
  1689 template (the former print_mode reference), thus access becomes
  1690 non-critical.  The global print_mode reference is for session
  1691 management only; user-code should use print_mode_value,
  1692 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1693 
  1694 * Functions system/system_out provide a robust way to invoke external
  1695 shell commands, with propagation of interrupts (requires Poly/ML
  1696 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1697 
  1698 
  1699 *** System ***
  1700 
  1701 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1702 in accordance with Proof General 3.7, which prefers GNU emacs.
  1703 
  1704 * isatool tty runs Isabelle process with plain tty interaction;
  1705 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1706 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1707 
  1708 * isatool browser now works with Cygwin as well, using general
  1709 "javapath" function defined in Isabelle process environment.
  1710 
  1711 * YXML notation provides a simple and efficient alternative to
  1712 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1713 isatool yxml as described in the Isabelle system manual.
  1714 
  1715 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1716 provides general wrapper for managing an Isabelle process in a robust
  1717 fashion, with ``cooked'' output from stdin/stderr.
  1718 
  1719 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1720 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1721 
  1722 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1723 way of changing the user's settings is via
  1724 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1725 script.
  1726 
  1727 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1728 cores of the underlying machine, which is a good starting point for
  1729 optimal performance tuning.  The corresponding usedir option -M allows
  1730 "max" as an alias for "0".  WARNING: does not work on certain versions
  1731 of Mac OS (with Poly/ML 5.1).
  1732 
  1733 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1734 adverse effect of Isabelle flooding interactive front-ends (notably
  1735 ProofGeneral / XEmacs).
  1736 
  1737 
  1738 
  1739 New in Isabelle2007 (November 2007)
  1740 -----------------------------------
  1741 
  1742 *** General ***
  1743 
  1744 * More uniform information about legacy features, notably a
  1745 warning/error of "Legacy feature: ...", depending on the state of the
  1746 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1747 legacy features will disappear eventually.
  1748 
  1749 * Theory syntax: the header format ``theory A = B + C:'' has been
  1750 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1751 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1752 
  1753 * Theory syntax: the old non-Isar theory file format has been
  1754 discontinued altogether.  Note that ML proof scripts may still be used
  1755 with Isar theories; migration is usually quite simple with the ML
  1756 function use_legacy_bindings.  INCOMPATIBILITY.
  1757 
  1758 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1759 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1760 quotes.
  1761 
  1762 * Theory loader: be more serious about observing the static theory
  1763 header specifications (including optional directories), but not the
  1764 accidental file locations of previously successful loads.  The strict
  1765 update policy of former update_thy is now already performed by
  1766 use_thy, so the former has been removed; use_thys updates several
  1767 theories simultaneously, just as 'imports' within a theory header
  1768 specification, but without merging the results.  Potential
  1769 INCOMPATIBILITY: may need to refine theory headers and commands
  1770 ROOT.ML which depend on load order.
  1771 
  1772 * Theory loader: optional support for content-based file
  1773 identification, instead of the traditional scheme of full physical
  1774 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1775 (cf. the system manual).  The new scheme allows to work with
  1776 non-finished theories in persistent session images, such that source
  1777 files may be moved later on without requiring reloads.
  1778 
  1779 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1780 file (with the same base name as the theory) are considered a legacy
  1781 feature, which will disappear eventually. Even now, the theory loader
  1782 no longer maintains dependencies on such files.
  1783 
  1784 * Syntax: the scope for resolving ambiguities via type-inference is
  1785 now limited to individual terms, instead of whole simultaneous
  1786 specifications as before. This greatly reduces the complexity of the
  1787 syntax module and improves flexibility by separating parsing and
  1788 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1789 'fixes' etc.) are required in rare situations.
  1790 
  1791 * Syntax: constants introduced by new-style packages ('definition',
  1792 'abbreviation' etc.) are passed through the syntax module in
  1793 ``authentic mode''. This means that associated mixfix annotations
  1794 really stick to such constants, independently of potential name space
  1795 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1796 trees are represented slightly differently, may need to adapt syntax
  1797 translations accordingly. Use CONST marker in 'translations' and
  1798 @{const_syntax} antiquotation in 'parse_translation' etc.
  1799 
  1800 * Legacy goal package: reduced interface to the bare minimum required
  1801 to keep existing proof scripts running.  Most other user-level
  1802 functions are now part of the OldGoals structure, which is *not* open
  1803 by default (consider isatool expandshort before open OldGoals).
  1804 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1805 these tend to cause confusion about the actual goal (!) context being
  1806 used here, which is not necessarily the same as the_context().
  1807 
  1808 * Command 'find_theorems': supports "*" wild-card in "name:"
  1809 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1810 support a specific search form (see ProofGeneral/CHANGES).
  1811 
  1812 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1813 by default, which means that "prems" (and also "fixed variables") are
  1814 suppressed from proof state output.  Note that the ProofGeneral
  1815 settings mechanism allows to change and save options persistently, but
  1816 older versions of Isabelle will fail to start up if a negative prems
  1817 limit is imposed.
  1818 
  1819 * Local theory targets may be specified by non-nested blocks of
  1820 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1821 contain definitions, theorems etc., including any derived mechanism
  1822 that has been implemented on top of these primitives.  This concept
  1823 generalizes the existing ``theorem (in ...)'' towards more versatility
  1824 and scalability.
  1825 
  1826 * Proof General interface: proper undo of final 'end' command;
  1827 discontinued Isabelle/classic mode (ML proof scripts).
  1828 
  1829 
  1830 *** Document preparation ***
  1831 
  1832 * Added antiquotation @{theory name} which prints the given name,
  1833 after checking that it refers to a valid ancestor theory in the
  1834 current context.
  1835 
  1836 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1837 check the given source text as ML type/structure, printing verbatim.
  1838 
  1839 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1840 "c args == rhs" given in the current context.  (Any number of
  1841 arguments may be given on the LHS.)
  1842 
  1843 
  1844 *** Pure ***
  1845 
  1846 * The 'class' package offers a combination of axclass and locale to
  1847 achieve Haskell-like type classes in Isabelle.  Definitions and
  1848 theorems within a class context produce both relative results (with
  1849 implicit parameters according to the locale context), and polymorphic
  1850 constants with qualified polymorphism (according to the class
  1851 context).  Within the body context of a 'class' target, a separate
  1852 syntax layer ("user space type system") takes care of converting
  1853 between global polymorphic consts and internal locale representation.
  1854 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1855 "isatool doc classes" provides a tutorial.
  1856 
  1857 * Generic code generator framework allows to generate executable
  1858 code for ML and Haskell (including Isabelle classes).  A short usage
  1859 sketch:
  1860 
  1861     internal compilation:
  1862         export_code <list of constants (term syntax)> in SML
  1863     writing SML code to a file:
  1864         export_code <list of constants (term syntax)> in SML <filename>
  1865     writing OCaml code to a file:
  1866         export_code <list of constants (term syntax)> in OCaml <filename>
  1867     writing Haskell code to a bunch of files:
  1868         export_code <list of constants (term syntax)> in Haskell <filename>
  1869 
  1870     evaluating closed propositions to True/False using code generation:
  1871         method ``eval''
  1872 
  1873 Reasonable default setup of framework in HOL.
  1874 
  1875 Theorem attributs for selecting and transforming function equations theorems:
  1876 
  1877     [code fun]:        select a theorem as function equation for a specific constant
  1878     [code fun del]:    deselect a theorem as function equation for a specific constant
  1879     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1880     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1881 
  1882 User-defined serializations (target in {SML, OCaml, Haskell}):
  1883 
  1884     code_const <and-list of constants (term syntax)>
  1885       {(target) <and-list of const target syntax>}+
  1886 
  1887     code_type <and-list of type constructors>
  1888       {(target) <and-list of type target syntax>}+
  1889 
  1890     code_instance <and-list of instances>
  1891       {(target)}+
  1892         where instance ::= <type constructor> :: <class>
  1893 
  1894     code_class <and_list of classes>
  1895       {(target) <and-list of class target syntax>}+
  1896         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1897 
  1898 code_instance and code_class only are effective to target Haskell.
  1899 
  1900 For example usage see src/HOL/ex/Codegenerator.thy and
  1901 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1902 generation from Isabelle/HOL theories is available via "isatool doc
  1903 codegen".
  1904 
  1905 * Code generator: consts in 'consts_code' Isar commands are now
  1906 referred to by usual term syntax (including optional type
  1907 annotations).
  1908 
  1909 * Command 'no_translations' removes translation rules from theory
  1910 syntax.
  1911 
  1912 * Overloaded definitions are now actually checked for acyclic
  1913 dependencies.  The overloading scheme is slightly more general than
  1914 that of Haskell98, although Isabelle does not demand an exact
  1915 correspondence to type class and instance declarations.
  1916 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1917 exotic versions of overloading -- at the discretion of the user!
  1918 
  1919 Polymorphic constants are represented via type arguments, i.e. the
  1920 instantiation that matches an instance against the most general
  1921 declaration given in the signature.  For example, with the declaration
  1922 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1923 as c(nat).  Overloading is essentially simultaneous structural
  1924 recursion over such type arguments.  Incomplete specification patterns
  1925 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1926 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1927 Command 'print_theory' outputs the normalized system of recursive
  1928 equations, see section "definitions".
  1929 
  1930 * Configuration options are maintained within the theory or proof
  1931 context (with name and type bool/int/string), providing a very simple
  1932 interface to a poor-man's version of general context data.  Tools may
  1933 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1934 these values using Config.get etc.  Users may change options via an
  1935 associated attribute of the same name.  This form of context
  1936 declaration works particularly well with commands 'declare' or
  1937 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1938 very easy to avoid global references, which would not observe Isar
  1939 toplevel undo/redo and fail to work with multithreading.
  1940 
  1941 Various global ML references of Pure and HOL have been turned into
  1942 configuration options:
  1943 
  1944   Unify.search_bound		unify_search_bound
  1945   Unify.trace_bound		unify_trace_bound
  1946   Unify.trace_simp		unify_trace_simp
  1947   Unify.trace_types		unify_trace_types
  1948   Simplifier.simp_depth_limit	simp_depth_limit
  1949   Blast.depth_limit		blast_depth_limit
  1950   DatatypeProp.dtK		datatype_distinctness_limit
  1951   fast_arith_neq_limit  	fast_arith_neq_limit
  1952   fast_arith_split_limit	fast_arith_split_limit
  1953 
  1954 * Named collections of theorems may be easily installed as context
  1955 data using the functor NamedThmsFun (see also
  1956 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1957 attributes; there is also a toplevel print command.  This facility is
  1958 just a common case of general context data, which is the preferred way
  1959 for anything more complex than just a list of facts in canonical
  1960 order.
  1961 
  1962 * Isar: command 'declaration' augments a local theory by generic
  1963 declaration functions written in ML.  This enables arbitrary content
  1964 being added to the context, depending on a morphism that tells the
  1965 difference of the original declaration context wrt. the application
  1966 context encountered later on.
  1967 
  1968 * Isar: proper interfaces for simplification procedures.  Command
  1969 'simproc_setup' declares named simprocs (with match patterns, and body
  1970 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1971 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1972 
  1973 * Isar: an extra pair of brackets around attribute declarations
  1974 abbreviates a theorem reference involving an internal dummy fact,
  1975 which will be ignored later --- only the effect of the attribute on
  1976 the background context will persist.  This form of in-place
  1977 declarations is particularly useful with commands like 'declare' and
  1978 'using', for example ``have A using [[simproc a]] by simp''.
  1979 
  1980 * Isar: method "assumption" (and implicit closing of subproofs) now
  1981 takes simple non-atomic goal assumptions into account: after applying
  1982 an assumption as a rule the resulting subgoals are solved by atomic
  1983 assumption steps.  This is particularly useful to finish 'obtain'
  1984 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1985 without referring to the original premise "!!x. P x ==> thesis" in the
  1986 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1987 more permissive.
  1988 
  1989 * Isar: implicit use of prems from the Isar proof context is
  1990 considered a legacy feature.  Common applications like ``have A .''
  1991 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1992 referencing facts explicitly here improves readability and
  1993 maintainability of proof texts.
  1994 
  1995 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1996 the obtained context from the course of reasoning!  For example:
  1997 
  1998   assume "EX x y. A x & B y"   -- "any previous fact"
  1999   then guess x and y by clarify
  2000 
  2001 This technique is potentially adventurous, depending on the facts and
  2002 proof tools being involved here.
  2003 
  2004 * Isar: known facts from the proof context may be specified as literal
  2005 propositions, using ASCII back-quote syntax.  This works wherever
  2006 named facts used to be allowed so far, in proof commands, proof
  2007 methods, attributes etc.  Literal facts are retrieved from the context
  2008 according to unification of type and term parameters.  For example,
  2009 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2010 theorems in the current context, then these are valid literal facts:
  2011 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2012 
  2013 There is also a proof method "fact" which does the same composition
  2014 for explicit goal states, e.g. the following proof texts coincide with
  2015 certain special cases of literal facts:
  2016 
  2017   have "A" by fact                 ==  note `A`
  2018   have "A ==> B" by fact           ==  note `A ==> B`
  2019   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2020   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2021 
  2022 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2023 outer syntax.  Thus symbolic identifiers may be used without
  2024 additional white space in declarations like this: ``assume *: A''.
  2025 
  2026 * Isar: 'print_facts' prints all local facts of the current context,
  2027 both named and unnamed ones.
  2028 
  2029 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2030 
  2031   def x == "t" and y == "u"
  2032 
  2033 * Isar: added command 'unfolding', which is structurally similar to
  2034 'using', but affects both the goal state and facts by unfolding given
  2035 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2036 'unfolded' attribute may be replaced by first-class proof text.
  2037 
  2038 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2039 and command 'unfolding' now all support object-level equalities
  2040 (potentially conditional).  The underlying notion of rewrite rule is
  2041 analogous to the 'rule_format' attribute, but *not* that of the
  2042 Simplifier (which is usually more generous).
  2043 
  2044 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2045 premises of a theorem by n. Useful in conjunction with drule.
  2046 
  2047 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2048 method expression within a sandbox consisting of the first N
  2049 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2050 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2051 simplifies all new goals that emerge from applying rule foo to the
  2052 originally first one.
  2053 
  2054 * Isar: schematic goals are no longer restricted to higher-order
  2055 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2056 expected.
  2057 
  2058 * Isar: the conclusion of a long theorem statement is now either
  2059 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2060 (essentially a disjunction of cases with local parameters and
  2061 assumptions).  The latter allows to express general elimination rules
  2062 adequately; in this notation common elimination rules look like this:
  2063 
  2064   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2065     assumes "EX x. P x"
  2066     obtains x where "P x"
  2067 
  2068   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2069     assumes "A & B"
  2070     obtains A and B
  2071 
  2072   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2073     assumes "A | B"
  2074     obtains
  2075       A
  2076     | B
  2077 
  2078 The subsequent classical rules even refer to the formal "thesis"
  2079 explicitly:
  2080 
  2081   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2082     obtains "~ thesis"
  2083 
  2084   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2085     obtains "thesis ==> something"
  2086 
  2087 The actual proof of an 'obtains' statement is analogous to that of the
  2088 Isar proof element 'obtain', only that there may be several cases.
  2089 Optional case names may be specified in parentheses; these will be
  2090 available both in the present proof and as annotations in the
  2091 resulting rule, for later use with the 'cases' method (cf. attribute
  2092 case_names).
  2093 
  2094 * Isar: the assumptions of a long theorem statement are available as
  2095 "assms" fact in the proof context.  This is more appropriate than the
  2096 (historical) "prems", which refers to all assumptions of the current
  2097 context, including those from the target locale, proof body etc.
  2098 
  2099 * Isar: 'print_statement' prints theorems from the current theory or
  2100 proof context in long statement form, according to the syntax of a
  2101 top-level lemma.
  2102 
  2103 * Isar: 'obtain' takes an optional case name for the local context
  2104 introduction rule (default "that").
  2105 
  2106 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2107 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2108 to occur.
  2109 
  2110 * Pure: syntax "CONST name" produces a fully internalized constant
  2111 according to the current context.  This is particularly useful for
  2112 syntax translations that should refer to internal constant
  2113 representations independently of name spaces.
  2114 
  2115 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2116 instead of "FOO ". This allows multiple binder declarations to coexist
  2117 in the same context.  INCOMPATIBILITY.
  2118 
  2119 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2120 primitive that also works in a locale context (both for constants and
  2121 fixed variables). Type declaration and internal syntactic representation
  2122 of given constants retrieved from the context. Likewise, the
  2123 'no_notation' command allows to remove given syntax annotations from the
  2124 current context.
  2125 
  2126 * Isar/locales: new derived specification elements 'axiomatization',
  2127 'definition', 'abbreviation', which support type-inference, admit
  2128 object-level specifications (equality, equivalence).  See also the
  2129 isar-ref manual.  Examples:
  2130 
  2131   axiomatization
  2132     eq  (infix "===" 50) where
  2133     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2134 
  2135   definition "f x y = x + y + 1"
  2136   definition g where "g x = f x x"
  2137 
  2138   abbreviation
  2139     neq  (infix "=!=" 50) where
  2140     "x =!= y == ~ (x === y)"
  2141 
  2142 These specifications may be also used in a locale context.  Then the
  2143 constants being introduced depend on certain fixed parameters, and the
  2144 constant name is qualified by the locale base name.  An internal
  2145 abbreviation takes care for convenient input and output, making the
  2146 parameters implicit and using the original short name.  See also
  2147 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2148 entities from a monomorphic theory.
  2149 
  2150 Presently, abbreviations are only available 'in' a target locale, but
  2151 not inherited by general import expressions.  Also note that
  2152 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2153 'translations' in common applications.  The "no_abbrevs" print mode
  2154 prevents folding of abbreviations in term output.
  2155 
  2156 Concrete syntax is attached to specified constants in internal form,
  2157 independently of name spaces.  The parse tree representation is
  2158 slightly different -- use 'notation' instead of raw 'syntax', and
  2159 'translations' with explicit "CONST" markup to accommodate this.
  2160 
  2161 * Pure/Isar: unified syntax for new-style specification mechanisms
  2162 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2163 full type inference and dummy patterns ("_").  For example:
  2164 
  2165   definition "K x _ = x"
  2166 
  2167   inductive conj for A B
  2168   where "A ==> B ==> conj A B"
  2169 
  2170 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2171 the current context.  Print mode "no_abbrevs" prevents inversion of
  2172 abbreviations on output.
  2173 
  2174 * Isar/locales: improved parameter handling: use of locales "var" and
  2175 "struct" no longer necessary; - parameter renamings are no longer
  2176 required to be injective.  For example, this allows to define
  2177 endomorphisms as locale endom = homom mult mult h.
  2178 
  2179 * Isar/locales: changed the way locales with predicates are defined.
  2180 Instead of accumulating the specification, the imported expression is
  2181 now an interpretation.  INCOMPATIBILITY: different normal form of
  2182 locale expressions.  In particular, in interpretations of locales with
  2183 predicates, goals repesenting already interpreted fragments are not
  2184 removed automatically.  Use methods `intro_locales' and
  2185 `unfold_locales'; see below.
  2186 
  2187 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2188 provide backward reasoning on locales predicates.  The methods are
  2189 aware of interpretations and discharge corresponding goals.
  2190 `intro_locales' is less aggressive then `unfold_locales' and does not
  2191 unfold predicates to assumptions.
  2192 
  2193 * Isar/locales: the order in which locale fragments are accumulated
  2194 has changed.  This enables to override declarations from fragments due
  2195 to interpretations -- for example, unwanted simp rules.
  2196 
  2197 * Isar/locales: interpretation in theories and proof contexts has been
  2198 extended.  One may now specify (and prove) equations, which are
  2199 unfolded in interpreted theorems.  This is useful for replacing
  2200 defined concepts (constants depending on locale parameters) by
  2201 concepts already existing in the target context.  Example:
  2202 
  2203   interpretation partial_order ["op <= :: [int, int] => bool"]
  2204     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2205 
  2206 Typically, the constant `partial_order.less' is created by a
  2207 definition specification element in the context of locale
  2208 partial_order.
  2209 
  2210 * Method "induct": improved internal context management to support
  2211 local fixes and defines on-the-fly. Thus explicit meta-level
  2212 connectives !!  and ==> are rarely required anymore in inductive goals
  2213 (using object-logic connectives for this purpose has been long
  2214 obsolete anyway). Common proof patterns are explained in
  2215 src/HOL/Induct/Common_Patterns.thy, see also
  2216 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2217 examples.
  2218 
  2219 * Method "induct": improved handling of simultaneous goals. Instead of
  2220 introducing object-level conjunction, the statement is now split into
  2221 several conclusions, while the corresponding symbolic cases are nested
  2222 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2223 see src/HOL/Induct/Common_Patterns.thy, for example.
  2224 
  2225 * Method "induct": mutual induction rules are now specified as a list
  2226 of rule sharing the same induction cases. HOL packages usually provide
  2227 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2228 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2229 mutual induction rules differently, i.e. like this:
  2230 
  2231   (induct rule: foo_bar.inducts)
  2232   (induct set: foo bar)
  2233   (induct pred: foo bar)
  2234   (induct type: foo bar)
  2235 
  2236 The ML function ProjectRule.projections turns old-style rules into the
  2237 new format.
  2238 
  2239 * Method "coinduct": dual of induction, see
  2240 src/HOL/Library/Coinductive_List.thy for various examples.
  2241 
  2242 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2243 considered a legacy feature.
  2244 
  2245 * Attribute "symmetric" produces result with standardized schematic
  2246 variables (index 0).  Potential INCOMPATIBILITY.
  2247 
  2248 * Simplifier: by default the simplifier trace only shows top level
  2249 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2250 default. Thus there is less danger of being flooded by the trace. The
  2251 trace indicates where parts have been suppressed.
  2252   
  2253 * Provers/classical: removed obsolete classical version of elim_format
  2254 attribute; classical elim/dest rules are now treated uniformly when
  2255 manipulating the claset.
  2256 
  2257 * Provers/classical: stricter checks to ensure that supplied intro,
  2258 dest and elim rules are well-formed; dest and elim rules must have at
  2259 least one premise.
  2260 
  2261 * Provers/classical: attributes dest/elim/intro take an optional
  2262 weight argument for the rule (just as the Pure versions).  Weights are
  2263 ignored by automated tools, but determine the search order of single
  2264 rule steps.
  2265 
  2266 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2267 where the body does not mention the bound variable.  Note that dummy
  2268 patterns implicitly depend on their context of bounds, which makes
  2269 "{_. _}" match any set comprehension as expected.  Potential
  2270 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2271 constant "_idtdummy" in the binding position.
  2272 
  2273 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2274 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2275 for example "A -> B" => "Pi A (%_. B)".
  2276 
  2277 * Pure: 'class_deps' command visualizes the subclass relation, using
  2278 the graph browser tool.
  2279 
  2280 * Pure: 'print_theory' now suppresses certain internal declarations by
  2281 default; use '!' option for full details.
  2282 
  2283 
  2284 *** HOL ***
  2285 
  2286 * Method "metis" proves goals by applying the Metis general-purpose
  2287 resolution prover (see also http://gilith.com/software/metis/).
  2288 Examples are in the directory MetisExamples.  WARNING: the
  2289 Isabelle/HOL-Metis integration does not yet work properly with
  2290 multi-threading.
  2291   
  2292 * Command 'sledgehammer' invokes external automatic theorem provers as
  2293 background processes.  It generates calls to the "metis" method if
  2294 successful. These can be pasted into the proof.  Users do not have to
  2295 wait for the automatic provers to return.  WARNING: does not really
  2296 work with multi-threading.
  2297 
  2298 * New "auto_quickcheck" feature tests outermost goal statements for
  2299 potential counter-examples.  Controlled by ML references
  2300 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2301 5000 milliseconds).  Fails silently if statements is outside of
  2302 executable fragment, or any other codgenerator problem occurs.
  2303 
  2304 * New constant "undefined" with axiom "undefined x = undefined".
  2305 
  2306 * Added class "HOL.eq", allowing for code generation with polymorphic
  2307 equality.
  2308 
  2309 * Some renaming of class constants due to canonical name prefixing in
  2310 the new 'class' package:
  2311 
  2312     HOL.abs ~> HOL.abs_class.abs
  2313     HOL.divide ~> HOL.divide_class.divide
  2314     0 ~> HOL.zero_class.zero
  2315     1 ~> HOL.one_class.one
  2316     op + ~> HOL.plus_class.plus
  2317     op - ~> HOL.minus_class.minus
  2318     uminus ~> HOL.minus_class.uminus
  2319     op * ~> HOL.times_class.times
  2320     op < ~> HOL.ord_class.less
  2321     op <= > HOL.ord_class.less_eq
  2322     Nat.power ~> Power.power_class.power
  2323     Nat.size ~> Nat.size_class.size
  2324     Numeral.number_of ~> Numeral.number_class.number_of
  2325     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2326     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2327     Orderings.min ~> Orderings.ord_class.min
  2328     Orderings.max ~> Orderings.ord_class.max
  2329     Divides.op div ~> Divides.div_class.div
  2330     Divides.op mod ~> Divides.div_class.mod
  2331     Divides.op dvd ~> Divides.div_class.dvd
  2332 
  2333 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2334 
  2335 a) User-defined constants using any of the names "plus", "minus",
  2336 "times", "less" or "less_eq". The standard syntax translations for
  2337 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2338 names.
  2339 
  2340 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2341 INCOMPATIBILITY: use more specific names.
  2342 
  2343 c) Permutative equations (e.g. "a + b = b + a")
  2344 Since the change of names also changes the order of terms, permutative
  2345 rewrite rules may get applied in a different order. Experience shows
  2346 that this is rarely the case (only two adaptions in the whole Isabelle
  2347 distribution).  INCOMPATIBILITY: rewrite proofs
  2348 
  2349 d) ML code directly refering to constant names
  2350 This in general only affects hand-written proof tactics, simprocs and
  2351 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2352 Consider using @{const_name} antiquotation.
  2353 
  2354 * New class "default" with associated constant "default".
  2355 
  2356 * Function "sgn" is now overloaded and available on int, real, complex
  2357 (and other numeric types), using class "sgn".  Two possible defs of
  2358 sgn are given as equational assumptions in the classes sgn_if and
  2359 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2360 INCOMPATIBILITY.
  2361 
  2362 * Locale "partial_order" now unified with class "order" (cf. theory
  2363 Orderings), added parameter "less".  INCOMPATIBILITY.
  2364 
  2365 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2366 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2367 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2368 
  2369 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2370 changed order of proof goals in instance proofs.
  2371 
  2372 * The transitivity reasoner for partial and linear orders is set up
  2373 for classes "order" and "linorder".  Instances of the reasoner are available
  2374 in all contexts importing or interpreting the corresponding locales.
  2375 Method "order" invokes the reasoner separately; the reasoner
  2376 is also integrated with the Simplifier as a solver.  Diagnostic
  2377 command 'print_orders' shows the available instances of the reasoner
  2378 in the current context.
  2379 
  2380 * Localized monotonicity predicate in theory "Orderings"; integrated
  2381 lemmas max_of_mono and min_of_mono with this predicate.
  2382 INCOMPATIBILITY.
  2383 
  2384 * Formulation of theorem "dense" changed slightly due to integration
  2385 with new class dense_linear_order.
  2386 
  2387 * Uniform lattice theory development in HOL.
  2388 
  2389     constants "meet" and "join" now named "inf" and "sup"
  2390     constant "Meet" now named "Inf"
  2391 
  2392     classes "meet_semilorder" and "join_semilorder" now named
  2393       "lower_semilattice" and "upper_semilattice"
  2394     class "lorder" now named "lattice"
  2395     class "comp_lat" now named "complete_lattice"
  2396 
  2397     Instantiation of lattice classes allows explicit definitions
  2398     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2399 
  2400   INCOMPATIBILITY.  Theorem renames:
  2401 
  2402     meet_left_le            ~> inf_le1
  2403     meet_right_le           ~> inf_le2
  2404     join_left_le            ~> sup_ge1
  2405     join_right_le           ~> sup_ge2
  2406     meet_join_le            ~> inf_sup_ord
  2407     le_meetI                ~> le_infI
  2408     join_leI                ~> le_supI
  2409     le_meet                 ~> le_inf_iff
  2410     le_join                 ~> ge_sup_conv
  2411     meet_idempotent         ~> inf_idem
  2412     join_idempotent         ~> sup_idem
  2413     meet_comm               ~> inf_commute
  2414     join_comm               ~> sup_commute
  2415     meet_leI1               ~> le_infI1
  2416     meet_leI2               ~> le_infI2
  2417     le_joinI1               ~> le_supI1
  2418     le_joinI2               ~> le_supI2
  2419     meet_assoc              ~> inf_assoc
  2420     join_assoc              ~> sup_assoc
  2421     meet_left_comm          ~> inf_left_commute
  2422     meet_left_idempotent    ~> inf_left_idem
  2423     join_left_comm          ~> sup_left_commute
  2424     join_left_idempotent    ~> sup_left_idem
  2425     meet_aci                ~> inf_aci
  2426     join_aci                ~> sup_aci
  2427     le_def_meet             ~> le_iff_inf
  2428     le_def_join             ~> le_iff_sup
  2429     join_absorp2            ~> sup_absorb2
  2430     join_absorp1            ~> sup_absorb1
  2431     meet_absorp1            ~> inf_absorb1
  2432     meet_absorp2            ~> inf_absorb2
  2433     meet_join_absorp        ~> inf_sup_absorb
  2434     join_meet_absorp        ~> sup_inf_absorb
  2435     distrib_join_le         ~> distrib_sup_le
  2436     distrib_meet_le         ~> distrib_inf_le
  2437 
  2438     add_meet_distrib_left   ~> add_inf_distrib_left
  2439     add_join_distrib_left   ~> add_sup_distrib_left
  2440     is_join_neg_meet        ~> is_join_neg_inf
  2441     is_meet_neg_join        ~> is_meet_neg_sup
  2442     add_meet_distrib_right  ~> add_inf_distrib_right
  2443     add_join_distrib_right  ~> add_sup_distrib_right
  2444     add_meet_join_distribs  ~> add_sup_inf_distribs
  2445     join_eq_neg_meet        ~> sup_eq_neg_inf
  2446     meet_eq_neg_join        ~> inf_eq_neg_sup
  2447     add_eq_meet_join        ~> add_eq_inf_sup
  2448     meet_0_imp_0            ~> inf_0_imp_0
  2449     join_0_imp_0            ~> sup_0_imp_0
  2450     meet_0_eq_0             ~> inf_0_eq_0
  2451     join_0_eq_0             ~> sup_0_eq_0
  2452     neg_meet_eq_join        ~> neg_inf_eq_sup
  2453     neg_join_eq_meet        ~> neg_sup_eq_inf
  2454     join_eq_if              ~> sup_eq_if
  2455 
  2456     mono_meet               ~> mono_inf
  2457     mono_join               ~> mono_sup
  2458     meet_bool_eq            ~> inf_bool_eq
  2459     join_bool_eq            ~> sup_bool_eq
  2460     meet_fun_eq             ~> inf_fun_eq
  2461     join_fun_eq             ~> sup_fun_eq
  2462     meet_set_eq             ~> inf_set_eq
  2463     join_set_eq             ~> sup_set_eq
  2464     meet1_iff               ~> inf1_iff
  2465     meet2_iff               ~> inf2_iff
  2466     meet1I                  ~> inf1I
  2467     meet2I                  ~> inf2I
  2468     meet1D1                 ~> inf1D1
  2469     meet2D1                 ~> inf2D1
  2470     meet1D2                 ~> inf1D2
  2471     meet2D2                 ~> inf2D2
  2472     meet1E                  ~> inf1E
  2473     meet2E                  ~> inf2E
  2474     join1_iff               ~> sup1_iff
  2475     join2_iff               ~> sup2_iff
  2476     join1I1                 ~> sup1I1
  2477     join2I1                 ~> sup2I1
  2478     join1I1                 ~> sup1I1
  2479     join2I2                 ~> sup1I2
  2480     join1CI                 ~> sup1CI
  2481     join2CI                 ~> sup2CI
  2482     join1E                  ~> sup1E
  2483     join2E                  ~> sup2E
  2484 
  2485     is_meet_Meet            ~> is_meet_Inf
  2486     Meet_bool_def           ~> Inf_bool_def
  2487     Meet_fun_def            ~> Inf_fun_def
  2488     Meet_greatest           ~> Inf_greatest
  2489     Meet_lower              ~> Inf_lower
  2490     Meet_set_def            ~> Inf_set_def
  2491 
  2492     Sup_def                 ~> Sup_Inf
  2493     Sup_bool_eq             ~> Sup_bool_def
  2494     Sup_fun_eq              ~> Sup_fun_def
  2495     Sup_set_eq              ~> Sup_set_def
  2496 
  2497     listsp_meetI            ~> listsp_infI
  2498     listsp_meet_eq          ~> listsp_inf_eq
  2499 
  2500     meet_min                ~> inf_min
  2501     join_max                ~> sup_max
  2502 
  2503 * Added syntactic class "size"; overloaded constant "size" now has
  2504 type "'a::size ==> bool"
  2505 
  2506 * Internal reorganisation of `size' of datatypes: size theorems
  2507 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2508 simplification rules by default!); theorems "prod.size" now named
  2509 "*.size".
  2510 
  2511 * Class "div" now inherits from class "times" rather than "type".
  2512 INCOMPATIBILITY.
  2513 
  2514 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2515 Linorder etc.  have disappeared; operations defined in terms of
  2516 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2517 
  2518 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2519 
  2520 * HOL-Word: New extensive library and type for generic, fixed size
  2521 machine words, with arithemtic, bit-wise, shifting and rotating
  2522 operations, reflection into int, nat, and bool lists, automation for
  2523 linear arithmetic (by automatic reflection into nat or int), including
  2524 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2525 arithmetic type classes, supporting automatic simplification of
  2526 numerals on all operations.
  2527 
  2528 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2529 
  2530 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2531 
  2532 * Code generator library theories:
  2533   - Code_Integer represents HOL integers by big integer literals in target
  2534     languages.
  2535   - Code_Char represents HOL characters by character literals in target
  2536     languages.
  2537   - Code_Char_chr like Code_Char, but also offers treatment of character
  2538     codes; includes Code_Integer.
  2539   - Executable_Set allows to generate code for finite sets using lists.
  2540   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2541     denominator).
  2542   - Executable_Real implements a subset of real numbers, namly those
  2543     representable by rational numbers.
  2544   - Efficient_Nat implements natural numbers by integers, which in general will
  2545     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2546     includes Code_Integer.
  2547   - Code_Index provides an additional datatype index which is mapped to
  2548     target-language built-in integers.
  2549   - Code_Message provides an additional datatype message_string which is isomorphic to
  2550     strings; messages are mapped to target-language strings.
  2551 
  2552 * New package for inductive predicates
  2553 
  2554   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2555 
  2556     inductive
  2557       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2558       for z_1 :: U_1 and ... and z_n :: U_m
  2559     where
  2560       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2561     | ...
  2562 
  2563   with full support for type-inference, rather than
  2564 
  2565     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2566 
  2567     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2568     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2569 
  2570     inductive "s z_1 ... z_m"
  2571     intros
  2572       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2573       ...
  2574 
  2575   For backward compatibility, there is a wrapper allowing inductive
  2576   sets to be defined with the new package via
  2577 
  2578     inductive_set
  2579       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2580       for z_1 :: U_1 and ... and z_n :: U_m
  2581     where
  2582       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2583     | ...
  2584 
  2585   or
  2586 
  2587     inductive_set
  2588       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2589       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2590       for z_1 :: U_1 and ... and z_n :: U_m
  2591     where
  2592       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2593     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2594     | ...
  2595 
  2596   if the additional syntax "p ..." is required.
  2597 
  2598   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2599   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2600 
  2601   INCOMPATIBILITIES:
  2602 
  2603   - Since declaration and definition of inductive sets or predicates
  2604     is no longer separated, abbreviations involving the newly
  2605     introduced sets or predicates must be specified together with the
  2606     introduction rules after the 'where' keyword (see above), rather
  2607     than before the actual inductive definition.
  2608 
  2609   - The variables in induction and elimination rules are now
  2610     quantified in the order of their occurrence in the introduction
  2611     rules, rather than in alphabetical order. Since this may break
  2612     some proofs, these proofs either have to be repaired, e.g. by
  2613     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2614     statements of the form
  2615 
  2616       case (rule_i a_i_1 ... a_i_{k_i})
  2617 
  2618     or the old order of quantification has to be restored by explicitly adding
  2619     meta-level quantifiers in the introduction rules, i.e.
  2620 
  2621       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2622 
  2623   - The format of the elimination rules is now
  2624 
  2625       p z_1 ... z_m x_1 ... x_n ==>
  2626         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2627         ==> ... ==> P
  2628 
  2629     for predicates and
  2630 
  2631       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2632         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2633         ==> ... ==> P
  2634 
  2635     for sets rather than
  2636 
  2637       x : s z_1 ... z_m ==>
  2638         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2639         ==> ... ==> P
  2640 
  2641     This may require terms in goals to be expanded to n-tuples
  2642     (e.g. using case_tac or simplification with the split_paired_all
  2643     rule) before the above elimination rule is applicable.
  2644 
  2645   - The elimination or case analysis rules for (mutually) inductive
  2646     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2647     list of rules "p_1_..._p_k.elims" is no longer available.
  2648 
  2649 * New package "function"/"fun" for general recursive functions,
  2650 supporting mutual and nested recursion, definitions in local contexts,
  2651 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2652 for small examples, and the separate tutorial on the function
  2653 package. The old recdef "package" is still available as before, but
  2654 users are encouraged to use the new package.
  2655 
  2656 * Method "lexicographic_order" automatically synthesizes termination
  2657 relations as lexicographic combinations of size measures. 
  2658 
  2659 * Case-expressions allow arbitrary constructor-patterns (including
  2660 "_") and take their order into account, like in functional
  2661 programming.  Internally, this is translated into nested
  2662 case-expressions; missing cases are added and mapped to the predefined
  2663 constant "undefined". In complicated cases printing may no longer show
  2664 the original input but the internal form. Lambda-abstractions allow
  2665 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2666 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2667 variable.
  2668 
  2669 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2670 is an abbreviation for "of_nat :: nat => int". The simplification
  2671 rules for "of_nat" have been changed to work like "int" did
  2672 previously.  Potential INCOMPATIBILITY:
  2673   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2674   - of_nat_diff and of_nat_mult are no longer default simp rules
  2675 
  2676 * Method "algebra" solves polynomial equations over (semi)rings using
  2677 Groebner bases. The (semi)ring structure is defined by locales and the
  2678 tool setup depends on that generic context. Installing the method for
  2679 a specific type involves instantiating the locale and possibly adding
  2680 declarations for computation on the coefficients.  The method is
  2681 already instantiated for natural numbers and for the axiomatic class
  2682 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2683 CALCULEMUS 2007 for the general principles underlying this
  2684 architecture of context-aware proof-tools.
  2685 
  2686 * Method "ferrack" implements quantifier elimination over
  2687 special-purpose dense linear orders using locales (analogous to
  2688 "algebra"). The method is already installed for class
  2689 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2690 rat, etc.
  2691 
  2692 * Former constant "List.op @" now named "List.append".  Use ML
  2693 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2694 circumvent possible incompatibilities when working on ML level.
  2695 
  2696 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2697 
  2698 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2699 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2700 
  2701 * New syntax for Haskell-like list comprehension (input only), eg.
  2702 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2703 
  2704 * The special syntax for function "filter" has changed from [x :
  2705 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2706 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2707 
  2708 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2709 defined on nat only, as an abbreviation for [a..<Suc b]
  2710 INCOMPATIBILITY.
  2711 
  2712 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2713 
  2714 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2715 
  2716 * New lemma collection field_simps (an extension of ring_simps) for
  2717 manipulating (in)equations involving division. Multiplies with all
  2718 denominators that can be proved to be non-zero (in equations) or
  2719 positive/negative (in inequations).
  2720 
  2721 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2722 have been improved and renamed to ring_simps, group_simps and
  2723 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2724 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2725 
  2726 * Theory Library/Commutative_Ring: switched from recdef to function
  2727 package; constants add, mul, pow now curried.  Infix syntax for
  2728 algebraic operations.
  2729 
  2730 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2731 INCOMPATIBILITY.
  2732 
  2733 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2734 INCOMPATIBILITY.
  2735 
  2736 * HOL/records: generalised field-update to take a function on the
  2737 field rather than the new value: r(|A := x|) is translated to A_update
  2738 (K x) r The K-combinator that is internally used is called K_record.
  2739 INCOMPATIBILITY: Usage of the plain update functions has to be
  2740 adapted.
  2741  
  2742 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2743 * x = 0, which are required for a semiring.  Richer structures do not
  2744 inherit from semiring_0 anymore, because this property is a theorem
  2745 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2746 there is more to prove, but this is mostly trivial.
  2747 
  2748 * Class "recpower" is generalized to arbitrary monoids, not just
  2749 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2750 commutativity or semiring properties additionally.
  2751 
  2752 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2753 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2754 better use 'abbreviation'.
  2755 
  2756 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2757 
  2758 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2759 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2760 significant changes for setting up numeral syntax for types:
  2761   - New constants Numeral.pred and Numeral.succ instead
  2762       of former Numeral.bin_pred and Numeral.bin_succ.
  2763   - Use integer operations instead of bin_add, bin_mult and so on.
  2764   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2765   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2766 
  2767 See src/HOL/Integ/IntArith.thy for an example setup.
  2768 
  2769 * Command 'normal_form' computes the normal form of a term that may
  2770 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2771 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2772 heavy-duty computations because the functions are compiled to ML
  2773 first.  Correspondingly, a method "normalization" is provided.  See
  2774 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2775 
  2776 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2777 25 like -->); output depends on the "iff" print_mode, the default is
  2778 "A = B" (with priority 50).
  2779 
  2780 * Relations less (<) and less_eq (<=) are also available on type bool.
  2781 Modified syntax to disallow nesting without explicit parentheses,
  2782 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2783 INCOMPATIBILITY.
  2784 
  2785 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2786 
  2787 * Relation composition operator "op O" now has precedence 75 and binds
  2788 stronger than union and intersection. INCOMPATIBILITY.
  2789 
  2790 * The old set interval syntax "{m..n(}" (and relatives) has been
  2791 removed.  Use "{m..<n}" (and relatives) instead.
  2792 
  2793 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2794 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2795 ``declare [[simproc del: neq]]''.
  2796 
  2797 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2798 True/False.
  2799 
  2800 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2801 
  2802 * Theorem setsum_mult renamed to setsum_right_distrib.
  2803 
  2804 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2805 ``rule'' method.
  2806 
  2807 * Reimplemented methods "sat" and "satx", with several improvements:
  2808 goals no longer need to be stated as "<prems> ==> False", equivalences
  2809 (i.e. "=" on type bool) are handled, variable names of the form
  2810 "lit_<n>" are no longer reserved, significant speedup.
  2811 
  2812 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2813 zChaff is still supported as well.
  2814 
  2815 * 'inductive' and 'datatype': provide projections of mutual rules,
  2816 bundled as foo_bar.inducts;
  2817 
  2818 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2819 Library.
  2820 
  2821 * Library: moved theory Accessible_Part to main HOL.
  2822 
  2823 * Library: added theory Coinductive_List of potentially infinite lists
  2824 as greatest fixed-point.
  2825 
  2826 * Library: added theory AssocList which implements (finite) maps as
  2827 association lists.
  2828 
  2829 * Method "evaluation" solves goals (i.e. a boolean expression)
  2830 efficiently by compiling it to ML.  The goal is "proved" (via an
  2831 oracle) if it evaluates to True.
  2832 
  2833 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2834 also when invoked by the simplifier.  This results in the Simplifier
  2835 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2836 Configuration option fast_arith_split_limit=0 recovers the old
  2837 behavior.
  2838 
  2839 * Support for hex (0x20) and binary (0b1001) numerals.
  2840 
  2841 * New method: reify eqs (t), where eqs are equations for an
  2842 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2843 parameter, computes a term s::'b and a list xs::'a list and proves the
  2844 theorem I xs s = t. This is also known as reification or quoting. The
  2845 resulting theorem is applied to the subgoal to substitute t with I xs
  2846 s.  If t is omitted, the subgoal itself is reified.
  2847 
  2848 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2849 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2850 where f is supposed to be a computable function (in the sense of code
  2851 generattion). The method uses reify to compute s and xs as above then
  2852 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2853 r and finally gets the theorem t = r, which is again applied to the
  2854 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2855 
  2856 * Reflection: Automatic reification now handels binding, an example is
  2857 available in src/HOL/ex/ReflectionEx.thy
  2858 
  2859 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2860 command 'statespace' that is similar to 'record', but introduces an
  2861 abstract specification based on the locale infrastructure instead of
  2862 HOL types.  This leads to extra flexibility in composing state spaces,
  2863 in particular multiple inheritance and renaming of components.
  2864 
  2865 
  2866 *** HOL-Complex ***
  2867 
  2868 * Hyperreal: Functions root and sqrt are now defined on negative real
  2869 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2870 Nonnegativity side conditions have been removed from many lemmas, so
  2871 that more subgoals may now be solved by simplification; potential
  2872 INCOMPATIBILITY.
  2873 
  2874 * Real: new type classes formalize real normed vector spaces and
  2875 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2876 and norm :: 'a => real.
  2877 
  2878 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2879 reals into other types. The overloaded constant Reals :: 'a set is now
  2880 defined as range of_real; potential INCOMPATIBILITY.
  2881 
  2882 * Real: proper support for ML code generation, including 'quickcheck'.
  2883 Reals are implemented as arbitrary precision rationals.
  2884 
  2885 * Hyperreal: Several constants that previously worked only for the
  2886 reals have been generalized, so they now work over arbitrary vector
  2887 spaces. Type annotations may need to be added in some cases; potential
  2888 INCOMPATIBILITY.
  2889 
  2890   Infinitesimal  :: ('a::real_normed_vector) star set
  2891   HFinite        :: ('a::real_normed_vector) star set
  2892   HInfinite      :: ('a::real_normed_vector) star set
  2893   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2894   monad          :: ('a::real_normed_vector) star => 'a star set
  2895   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2896   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2897   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2898   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2899   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2900   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2901   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2902   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2903   sgn            :: 'a::real_normed_vector => 'a
  2904   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2905 
  2906 * Complex: Some complex-specific constants are now abbreviations for
  2907 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2908 hnorm.  Other constants have been entirely removed in favor of the
  2909 polymorphic versions (INCOMPATIBILITY):
  2910 
  2911   approx        <-- capprox
  2912   HFinite       <-- CFinite
  2913   HInfinite     <-- CInfinite
  2914   Infinitesimal <-- CInfinitesimal
  2915   monad         <-- cmonad
  2916   galaxy        <-- cgalaxy
  2917   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2918   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2919   (ns)deriv     <-- (ns)cderiv
  2920 
  2921 
  2922 *** HOL-Algebra ***
  2923 
  2924 * Formalisation of ideals and the quotient construction over rings.
  2925 
  2926 * Order and lattice theory no longer based on records.
  2927 INCOMPATIBILITY.
  2928 
  2929 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2930 greatest_closed.  INCOMPATIBILITY.
  2931 
  2932 * Method algebra is now set up via an attribute.  For examples see
  2933 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2934 of algebraic structures.
  2935 
  2936 * Renamed theory CRing to Ring.
  2937 
  2938 
  2939 *** HOL-Nominal ***
  2940 
  2941 * Substantial, yet incomplete support for nominal datatypes (binding
  2942 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2943 src/HOL/Nominal/Examples.  Prospective users should consult
  2944 http://isabelle.in.tum.de/nominal/
  2945 
  2946 
  2947 *** ML ***
  2948 
  2949 * ML basics: just one true type int, which coincides with IntInf.int
  2950 (even on SML/NJ).
  2951 
  2952 * ML within Isar: antiquotations allow to embed statically-checked
  2953 formal entities in the source, referring to the context available at
  2954 compile-time.  For example:
  2955 
  2956 ML {* @{sort "{zero,one}"} *}
  2957 ML {* @{typ "'a => 'b"} *}
  2958 ML {* @{term "%x. x"} *}
  2959 ML {* @{prop "x == y"} *}
  2960 ML {* @{ctyp "'a => 'b"} *}
  2961 ML {* @{cterm "%x. x"} *}
  2962 ML {* @{cprop "x == y"} *}
  2963 ML {* @{thm asm_rl} *}
  2964 ML {* @{thms asm_rl} *}
  2965 ML {* @{type_name c} *}
  2966 ML {* @{type_syntax c} *}
  2967 ML {* @{const_name c} *}
  2968 ML {* @{const_syntax c} *}
  2969 ML {* @{context} *}
  2970 ML {* @{theory} *}
  2971 ML {* @{theory Pure} *}
  2972 ML {* @{theory_ref} *}
  2973 ML {* @{theory_ref Pure} *}
  2974 ML {* @{simpset} *}
  2975 ML {* @{claset} *}
  2976 ML {* @{clasimpset} *}
  2977 
  2978 The same works for sources being ``used'' within an Isar context.
  2979 
  2980 * ML in Isar: improved error reporting; extra verbosity with
  2981 ML_Context.trace enabled.
  2982 
  2983 * Pure/General/table.ML: the join operations now works via exceptions
  2984 DUP/SAME instead of type option. This is simpler in simple cases, and
  2985 admits slightly more efficient complex applications.
  2986 
  2987 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2988 use Context.generic instead of just theory.
  2989 
  2990 * Pure: datatype Context.generic joins theory/Proof.context and
  2991 provides some facilities for code that works in either kind of
  2992 context, notably GenericDataFun for uniform theory and proof data.
  2993 
  2994 * Pure: simplified internal attribute type, which is now always
  2995 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2996 local (Proof.context) attributes have been discontinued, while
  2997 minimizing code duplication. Thm.rule_attribute and
  2998 Thm.declaration_attribute build canonical attributes; see also structure
  2999 Context for further operations on Context.generic, notably
  3000 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3001 declarations and definitions.
  3002 
  3003 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3004 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3005 init only required for impure data. INCOMPATIBILITY: empty really need
  3006 to be empty (no dependencies on theory content!)
  3007 
  3008 * Pure/kernel: consts certification ignores sort constraints given in
  3009 signature declarations. (This information is not relevant to the
  3010 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3011 potential INCOMPATIBILITY.
  3012 
  3013 * Pure: axiomatic type classes are now purely definitional, with
  3014 explicit proofs of class axioms and super class relations performed
  3015 internally. See Pure/axclass.ML for the main internal interfaces --
  3016 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3017 AxClass.axiomatize_class/classrel/arity supersede
  3018 Sign.add_classes/classrel/arities.
  3019 
  3020 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3021 global/local versions on theory vs. Proof.context have been
  3022 discontinued; Attrib.syntax and Method.syntax have been adapted
  3023 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3024 attributes, methods, etc.
  3025 
  3026 * Pure: several functions of signature "... -> theory -> theory * ..."
  3027 have been reoriented to "... -> theory -> ... * theory" in order to
  3028 allow natural usage in combination with the ||>, ||>>, |-> and
  3029 fold_map combinators.
  3030 
  3031 * Pure: official theorem names (closed derivations) and additional
  3032 comments (tags) are now strictly separate.  Name hints -- which are
  3033 maintained as tags -- may be attached any time without affecting the
  3034 derivation.
  3035 
  3036 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3037 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3038 achieve the old behaviour.
  3039 
  3040 * Pure: the "Goal" constant is now called "prop", supporting a
  3041 slightly more general idea of ``protecting'' meta-level rule
  3042 statements.
  3043 
  3044 * Pure: Logic.(un)varify only works in a global context, which is now
  3045 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3046 Logic.legacy_(un)varify as temporary workaround.
  3047 
  3048 * Pure: structure Name provides scalable operations for generating
  3049 internal variable names, notably Name.variants etc.  This replaces
  3050 some popular functions from term.ML:
  3051 
  3052   Term.variant		->  Name.variant
  3053   Term.variantlist	->  Name.variant_list
  3054   Term.invent_names	->  Name.invent_list
  3055 
  3056 Note that low-level renaming rarely occurs in new code -- operations
  3057 from structure Variable are used instead (see below).
  3058 
  3059 * Pure: structure Variable provides fundamental operations for proper
  3060 treatment of fixed/schematic variables in a context.  For example,
  3061 Variable.import introduces fixes for schematics of given facts and
  3062 Variable.export reverses the effect (up to renaming) -- this replaces
  3063 various freeze_thaw operations.
  3064 
  3065 * Pure: structure Goal provides simple interfaces for
  3066 init/conclude/finish and tactical prove operations (replacing former
  3067 Tactic.prove).  Goal.prove is the canonical way to prove results
  3068 within a given context; Goal.prove_global is a degraded version for
  3069 theory level goals, including a global Drule.standard.  Note that
  3070 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3071 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3072 in a locale context).
  3073 
  3074 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3075 and type checking (Syntax.check_term etc.), with common combinations
  3076 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3077 which are considered legacy and await removal.
  3078 
  3079 * Pure/Syntax: generic interfaces for type unchecking
  3080 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3081 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3082 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3083 available for convenience, but refer to the very same operations using
  3084 a mere theory instead of a full context.
  3085 
  3086 * Isar: simplified treatment of user-level errors, using exception
  3087 ERROR of string uniformly.  Function error now merely raises ERROR,
  3088 without any side effect on output channels.  The Isar toplevel takes
  3089 care of proper display of ERROR exceptions.  ML code may use plain
  3090 handle/can/try; cat_error may be used to concatenate errors like this:
  3091 
  3092   ... handle ERROR msg => cat_error msg "..."
  3093 
  3094 Toplevel ML code (run directly or through the Isar toplevel) may be
  3095 embedded into the Isar toplevel with exception display/debug like
  3096 this:
  3097 
  3098   Isar.toplevel (fn () => ...)
  3099 
  3100 INCOMPATIBILITY, removed special transform_error facilities, removed
  3101 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3102 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3103 -- use plain ERROR instead.
  3104 
  3105 * Isar: theory setup now has type (theory -> theory), instead of a
  3106 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3107 
  3108 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3109 ProofContext.debug/verbose flags.
  3110 
  3111 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3112 theory before entering a proof state.  Transactions now always see a
  3113 quasi-functional intermediate checkpoint, both in interactive and
  3114 batch mode.
  3115 
  3116 * Isar: simplified interfaces for outer syntax.  Renamed
  3117 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3118 OuterSyntax.add_parsers -- this functionality is now included in
  3119 OuterSyntax.command etc.  INCOMPATIBILITY.
  3120 
  3121 * Simplifier: the simpset of a running simplification process now
  3122 contains a proof context (cf. Simplifier.the_context), which is the
  3123 very context that the initial simpset has been retrieved from (by
  3124 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3125 (solver, looper etc.) may depend on arbitrary proof data.
  3126 
  3127 * Simplifier.inherit_context inherits the proof context (plus the
  3128 local bounds) of the current simplification process; any simproc
  3129 etc. that calls the Simplifier recursively should do this!  Removed
  3130 former Simplifier.inherit_bounds, which is already included here --
  3131 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3132 specify an explicit context using Simplifier.context/theory_context.
  3133 
  3134 * Simplifier/Classical Reasoner: more abstract interfaces
  3135 change_simpset/claset for modifying the simpset/claset reference of a
  3136 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3137 INCOMPATIBILITY.
  3138 
  3139 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3140 "Trueprop" etc.
  3141 
  3142 
  3143 *** System ***
  3144 
  3145 * settings: the default heap location within ISABELLE_HOME_USER now
  3146 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3147 Isabelle installations.
  3148 
  3149 * isabelle-process: option -S (secure mode) disables some critical
  3150 operations, notably runtime compilation and evaluation of ML source
  3151 code.
  3152 
  3153 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3154 
  3155 * Support for parallel execution, using native multicore support of
  3156 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3157 independent theories, according to the given theory header
  3158 specifications. The maximum number of worker threads is specified via
  3159 usedir option -M or the "max-threads" setting in Proof General. A
  3160 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3161 to 6 on a 8-core machine.  User-code needs to observe certain
  3162 guidelines for thread-safe programming, see appendix A in the Isar
  3163 Implementation manual.
  3164 
  3165 
  3166 
  3167 New in Isabelle2005 (October 2005)
  3168 ----------------------------------
  3169 
  3170 *** General ***
  3171 
  3172 * Theory headers: the new header syntax for Isar theories is
  3173 
  3174   theory <name>
  3175   imports <theory1> ... <theoryN>
  3176   uses <file1> ... <fileM>
  3177   begin
  3178 
  3179 where the 'uses' part is optional.  The previous syntax
  3180 
  3181   theory <name> = <theory1> + ... + <theoryN>:
  3182 
  3183 will disappear in the next release.  Use isatool fixheaders to convert
  3184 existing theory files.  Note that there is no change in ancient
  3185 non-Isar theories now, but these will disappear soon.
  3186 
  3187 * Theory loader: parent theories can now also be referred to via
  3188 relative and absolute paths.
  3189 
  3190 * Command 'find_theorems' searches for a list of criteria instead of a
  3191 list of constants. Known criteria are: intro, elim, dest, name:string,
  3192 simp:term, and any term. Criteria can be preceded by '-' to select
  3193 theorems that do not match. Intro, elim, dest select theorems that
  3194 match the current goal, name:s selects theorems whose fully qualified
  3195 name contain s, and simp:term selects all simplification rules whose
  3196 lhs match term.  Any other term is interpreted as pattern and selects
  3197 all theorems matching the pattern. Available in ProofGeneral under
  3198 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3199 
  3200   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3201 
  3202 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3203 matching the current goal as introduction rule and not having "HOL."
  3204 in their name (i.e. not being defined in theory HOL).
  3205 
  3206 * Command 'thms_containing' has been discontinued in favour of
  3207 'find_theorems'; INCOMPATIBILITY.
  3208 
  3209 * Communication with Proof General is now 8bit clean, which means that
  3210 Unicode text in UTF-8 encoding may be used within theory texts (both
  3211 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3212 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3213 
  3214   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3215   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3216 
  3217 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3218 Classical Reasoner.  Typical big applications run around 2 times
  3219 faster.
  3220 
  3221 
  3222 *** Document preparation ***
  3223 
  3224 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3225 of raw sources.  Only those symbols that do not require additional
  3226 LaTeX packages (depending on comments in isabellesym.sty) are
  3227 displayed properly, everything else is left verbatim.  isatool display
  3228 and isatool print are used as front ends (these are subject to the
  3229 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3230 
  3231 * Command tags control specific markup of certain regions of text,
  3232 notably folding and hiding.  Predefined tags include "theory" (for
  3233 theory begin and end), "proof" for proof commands, and "ML" for
  3234 commands involving ML code; the additional tags "visible" and
  3235 "invisible" are unused by default.  Users may give explicit tag
  3236 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3237 interpretation of tags is determined by the LaTeX job during document
  3238 preparation: see option -V of isatool usedir, or options -n and -t of
  3239 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3240 \isadroptag.
  3241 
  3242 Several document versions may be produced at the same time via isatool
  3243 usedir (the generated index.html will link all of them).  Typical
  3244 specifications include ''-V document=theory,proof,ML'' to present
  3245 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3246 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3247 these parts without any formal replacement text.  The Isabelle site
  3248 default settings produce ''document'' and ''outline'' versions as
  3249 specified above.
  3250 
  3251 * Several new antiquotations:
  3252 
  3253   @{term_type term} prints a term with its type annotated;
  3254 
  3255   @{typeof term} prints the type of a term;
  3256 
  3257   @{const const} is the same as @{term const}, but checks that the
  3258   argument is a known logical constant;
  3259 
  3260   @{term_style style term} and @{thm_style style thm} print a term or
  3261   theorem applying a "style" to it
  3262 
  3263   @{ML text}
  3264 
  3265 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3266 definitions, equations, inequations etc., 'concl' printing only the
  3267 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3268 to print the specified premise.  TermStyle.add_style provides an ML
  3269 interface for introducing further styles.  See also the "LaTeX Sugar"
  3270 document practical applications.  The ML antiquotation prints
  3271 type-checked ML expressions verbatim.
  3272 
  3273 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3274 and 'text' support optional locale specification '(in loc)', which
  3275 specifies the default context for interpreting antiquotations.  For
  3276 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3277 
  3278 * Option 'locale=NAME' of antiquotations specifies an alternative
  3279 context interpreting the subsequent argument.  For example: @{thm
  3280 [locale=lattice] inf_assoc}.
  3281 
  3282 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3283 a proof context.
  3284 
  3285 * Proper output of antiquotations for theory commands involving a
  3286 proof context (such as 'locale' or 'theorem (in loc) ...').
  3287 
  3288 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3289 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3290 
  3291 * isatool usedir: new option -C (default true) controls whether option
  3292 -D should include a copy of the original document directory; -C false
  3293 prevents unwanted effects such as copying of administrative CVS data.
  3294 
  3295 
  3296 *** Pure ***
  3297 
  3298 * Considerably improved version of 'constdefs' command.  Now performs
  3299 automatic type-inference of declared constants; additional support for
  3300 local structure declarations (cf. locales and HOL records), see also
  3301 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3302 sequential dependencies of definitions within a single 'constdefs'
  3303 section; moreover, the declared name needs to be an identifier.  If
  3304 all fails, consider to fall back on 'consts' and 'defs' separately.
  3305 
  3306 * Improved indexed syntax and implicit structures.  First of all,
  3307 indexed syntax provides a notational device for subscripted
  3308 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3309 expressions.  Secondly, in a local context with structure
  3310 declarations, number indexes \<^sub>n or the empty index (default
  3311 number 1) refer to a certain fixed variable implicitly; option
  3312 show_structs controls printing of implicit structures.  Typical
  3313 applications of these concepts involve record types and locales.
  3314 
  3315 * New command 'no_syntax' removes grammar declarations (and
  3316 translations) resulting from the given syntax specification, which is
  3317 interpreted in the same manner as for the 'syntax' command.
  3318 
  3319 * 'Advanced' translation functions (parse_translation etc.) may depend
  3320 on the signature of the theory context being presently used for
  3321 parsing/printing, see also isar-ref manual.
  3322 
  3323 * Improved 'oracle' command provides a type-safe interface to turn an
  3324 ML expression of type theory -> T -> term into a primitive rule of
  3325 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3326 is already included here); see also FOL/ex/IffExample.thy;
  3327 INCOMPATIBILITY.
  3328 
  3329 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3330 before); "cI" is no longer bound, use "c.intro" instead.
  3331 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3332 axclasses vs. locales.
  3333 
  3334 * Improved internal renaming of symbolic identifiers -- attach primes
  3335 instead of base 26 numbers.
  3336 
  3337 * New flag show_question_marks controls printing of leading question
  3338 marks in schematic variable names.
  3339 
  3340 * In schematic variable names, *any* symbol following \<^isub> or
  3341 \<^isup> is now treated as part of the base name.  For example, the
  3342 following works without printing of awkward ".0" indexes:
  3343 
  3344   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3345     by simp
  3346 
  3347 * Inner syntax includes (*(*nested*) comments*).
  3348 
  3349 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3350 annotations as "(00...)".
  3351 
  3352 * Clear separation of logical types and nonterminals, where the latter
  3353 may only occur in 'syntax' specifications or type abbreviations.
  3354 Before that distinction was only partially implemented via type class
  3355 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3356 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3357 exotic syntax specifications may require further adaption
  3358 (e.g. Cube/Cube.thy).
  3359 
  3360 * Removed obsolete type class "logic", use the top sort {} instead.
  3361 Note that non-logical types should be declared as 'nonterminals'
  3362 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3363 specifications.
  3364 
  3365 * Attributes 'induct' and 'cases': type or set names may now be
  3366 locally fixed variables as well.
  3367 
  3368 * Simplifier: can now control the depth to which conditional rewriting
  3369 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3370 Limit.
  3371 
  3372 * Simplifier: simplification procedures may now take the current
  3373 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3374 interface), which is very useful for calling the Simplifier
  3375 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3376 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3377 low-level mk_simproc no longer applies Logic.varify internally, to
  3378 allow for use in a context of fixed variables.
  3379 
  3380 * thin_tac now works even if the assumption being deleted contains !!
  3381 or ==>.  More generally, erule now works even if the major premise of
  3382 the elimination rule contains !! or ==>.
  3383 
  3384 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3385 
  3386 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3387 from Pure, which contains all common declarations already.  Both
  3388 theories are defined via plain Isabelle/Isar .thy files.
  3389 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3390 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3391 use isatool fixcpure to adapt your theory and ML sources.
  3392 
  3393 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3394 selections of theorems in named facts via index ranges.
  3395 
  3396 * 'print_theorems': in theory mode, really print the difference
  3397 wrt. the last state (works for interactive theory development only),
  3398 in proof mode print all local facts (cf. 'print_facts');
  3399 
  3400 * 'hide': option '(open)' hides only base names.
  3401 
  3402 * More efficient treatment of intermediate checkpoints in interactive
  3403 theory development.
  3404 
  3405 * Code generator is now invoked via code_module (incremental code
  3406 generation) and code_library (modular code generation, ML structures
  3407 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3408 must be quoted when used as identifiers.
  3409 
  3410 * New 'value' command for reading, evaluating and printing terms using
  3411 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3412 quoted when used as identifier.
  3413 
  3414 
  3415 *** Locales ***
  3416 
  3417 * New commands for the interpretation of locale expressions in
  3418 theories (1), locales (2) and proof contexts (3).  These generate
  3419 proof obligations from the expression specification.  After the
  3420 obligations have been discharged, theorems of the expression are added
  3421 to the theory, target locale or proof context.  The synopsis of the
  3422 commands is a follows:
  3423 
  3424   (1) interpretation expr inst
  3425   (2) interpretation target < expr
  3426   (3) interpret expr inst
  3427 
  3428 Interpretation in theories and proof contexts require a parameter
  3429 instantiation of terms from the current context.  This is applied to
  3430 specifications and theorems of the interpreted expression.
  3431 Interpretation in locales only permits parameter renaming through the
  3432 locale expression.  Interpretation is smart in that interpretations
  3433 that are active already do not occur in proof obligations, neither are
  3434 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3435 inspect active interpretations of a particular locale.  For details,
  3436 see the Isar Reference manual.  Examples can be found in
  3437 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3438 
  3439 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3440 'interpret' instead.
  3441 
  3442 * New context element 'constrains' for adding type constraints to
  3443 parameters.
  3444 
  3445 * Context expressions: renaming of parameters with syntax
  3446 redeclaration.
  3447 
  3448 * Locale declaration: 'includes' disallowed.
  3449 
  3450 * Proper static binding of attribute syntax -- i.e. types / terms /
  3451 facts mentioned as arguments are always those of the locale definition
  3452 context, independently of the context of later invocations.  Moreover,
  3453 locale operations (renaming and type / term instantiation) are applied
  3454 to attribute arguments as expected.
  3455 
  3456 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3457 actual attributes; rare situations may require Attrib.attribute to
  3458 embed those attributes into Attrib.src that lack concrete syntax.
  3459 Attribute implementations need to cooperate properly with the static
  3460 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3461 Attrib.XXX_thm etc. already do the right thing without further
  3462 intervention.  Only unusual applications -- such as "where" or "of"
  3463 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3464 on the context and the facts involved -- may have to assign parsed
  3465 values to argument tokens explicitly.
  3466 
  3467 * Changed parameter management in theorem generation for long goal
  3468 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3469 theorem statement in rare situations.
  3470 
  3471 * Locale inspection command 'print_locale' omits notes elements.  Use
  3472 'print_locale!' to have them included in the output.
  3473 
  3474 
  3475 *** Provers ***
  3476 
  3477 * Provers/hypsubst.ML: improved version of the subst method, for
  3478 single-step rewriting: it now works in bound variable contexts. New is
  3479 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3480 rewrite a different subterm than the original subst method, which is
  3481 still available as 'simplesubst'.
  3482 
  3483 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3484 and quasi orders.
  3485 
  3486 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3487 reflexive-transitive closure of relations.
  3488 
  3489 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3490 limit (previously hard-coded with a value of 20) user-definable.
  3491 
  3492 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3493 is peformed already.  Object-logics merely need to finish their
  3494 initial simpset configuration as before.  INCOMPATIBILITY.
  3495 
  3496 
  3497 *** HOL ***
  3498 
  3499 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3500 
  3501   syntax (epsilon)
  3502     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3503 
  3504 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3505 and x-symbol; use option '-m epsilon' to get it actually printed.
  3506 Moreover, the mathematically important symbolic identifier \<epsilon>
  3507 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3508 
  3509 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3510 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3511 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3512 support corresponding Isar calculations.
  3513 
  3514 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3515 instead of ":".
  3516 
  3517 * theory SetInterval: changed the syntax for open intervals:
  3518 
  3519   Old       New
  3520   {..n(}    {..<n}
  3521   {)n..}    {n<..}
  3522   {m..n(}   {m..<n}
  3523   {)m..n}   {m<..n}
  3524   {)m..n(}  {m<..<n}
  3525 
  3526 The old syntax is still supported but will disappear in the next
  3527 release.  For conversion use the following Emacs search and replace
  3528 patterns (these are not perfect but work quite well):
  3529 
  3530   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3531   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3532 
  3533 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3534 equalities in commutative rings; method 'algebra' provides a generic
  3535 interface.
  3536 
  3537 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3538 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3539 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3540 be a tuple pattern.
  3541 
  3542 Some new syntax forms are available:
  3543 
  3544   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3545   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3546   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3547   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3548 
  3549 The latter form "\<Sum>x < k. e" used to be based on a separate
  3550 function "Summation", which has been discontinued.
  3551 
  3552 * theory Finite_Set: in structured induction proofs, the insert case
  3553 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3554 (insert F x)'.
  3555 
  3556 * The 'refute' command has been extended to support a much larger
  3557 fragment of HOL, including axiomatic type classes, constdefs and
  3558 typedefs, inductive datatypes and recursion.
  3559 
  3560 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3561 Requires zChaff with proof generation to be installed.  See
  3562 HOL/ex/SAT_Examples.thy for examples.
  3563 
  3564 * Datatype induction via method 'induct' now preserves the name of the
  3565 induction variable. For example, when proving P(xs::'a list) by
  3566 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3567 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3568 in unstructured proof scripts.
  3569 
  3570 * Reworked implementation of records.  Improved scalability for
  3571 records with many fields, avoiding performance problems for type
  3572 inference. Records are no longer composed of nested field types, but
  3573 of nested extension types. Therefore the record type only grows linear
  3574 in the number of extensions and not in the number of fields.  The
  3575 top-level (users) view on records is preserved.  Potential
  3576 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3577 old record representation. The type generated for a record is called
  3578 <record_name>_ext_type.
  3579 
  3580 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3581 proofs triggered by a record definition or a simproc (if
  3582 quick_and_dirty is enabled).  Definitions of large records can take
  3583 quite long.
  3584 
  3585 New simproc record_upd_simproc for simplification of multiple record
  3586 updates enabled by default.  Moreover, trivial updates are also
  3587 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3588 occasionally, since simplification is more powerful by default.
  3589 
  3590 * typedef: proper support for polymorphic sets, which contain extra
  3591 type-variables in the term.
  3592 
  3593 * Simplifier: automatically reasons about transitivity chains
  3594 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3595 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3596 old proofs break occasionally as simplification may now solve more
  3597 goals than previously.
  3598 
  3599 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3600 present.  Works for all partial orders (class "order"), in particular
  3601 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3602 just like y <= x.
  3603 
  3604 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3605 bound variable or a constant then the let is unfolded.  Otherwise
  3606 first a is simplified to b, and then f b is simplified to g. If
  3607 possible we abstract b from g arriving at "let x = b in h x",
  3608 otherwise we unfold the let and arrive at g.  The simproc can be
  3609 enabled/disabled by the reference use_let_simproc.  Potential
  3610 INCOMPATIBILITY since simplification is more powerful by default.
  3611 
  3612 * Classical reasoning: the meson method now accepts theorems as arguments.
  3613 
  3614 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3615 jobs to provide advice on the provability of subgoals.
  3616 
  3617 * Theory OrderedGroup and Ring_and_Field: various additions and
  3618 improvements to faciliate calculations involving equalities and
  3619 inequalities.
  3620 
  3621 The following theorems have been eliminated or modified
  3622 (INCOMPATIBILITY):
  3623 
  3624   abs_eq             now named abs_of_nonneg
  3625   abs_of_ge_0        now named abs_of_nonneg
  3626   abs_minus_eq       now named abs_of_nonpos
  3627   imp_abs_id         now named abs_of_nonneg
  3628   imp_abs_neg_id     now named abs_of_nonpos
  3629   mult_pos           now named mult_pos_pos
  3630   mult_pos_le        now named mult_nonneg_nonneg
  3631   mult_pos_neg_le    now named mult_nonneg_nonpos
  3632   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3633   mult_neg           now named mult_neg_neg
  3634   mult_neg_le        now named mult_nonpos_nonpos
  3635 
  3636 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3637      
  3638      zero_le_square
  3639      not_square_less_zero 
  3640 
  3641   The following lemmas have been deleted from Real/RealPow:
  3642   
  3643      realpow_zero_zero
  3644      realpow_two
  3645      realpow_less
  3646      zero_le_power
  3647      realpow_two_le
  3648      abs_realpow_two
  3649      realpow_two_abs     
  3650 
  3651 * Theory Parity: added rules for simplifying exponents.
  3652 
  3653 * Theory List:
  3654 
  3655 The following theorems have been eliminated or modified
  3656 (INCOMPATIBILITY):
  3657 
  3658   list_all_Nil       now named list_all.simps(1)
  3659   list_all_Cons      now named list_all.simps(2)
  3660   list_all_conv      now named list_all_iff
  3661   set_mem_eq         now named mem_iff
  3662 
  3663 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3664 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3665 
  3666 
  3667 *** HOL-Complex ***
  3668 
  3669 * Theory RealDef: better support for embedding natural numbers and
  3670 integers in the reals.
  3671 
  3672 The following theorems have been eliminated or modified
  3673 (INCOMPATIBILITY):
  3674 
  3675   exp_ge_add_one_self  now requires no hypotheses
  3676   real_of_int_add      reversed direction of equality (use [symmetric])
  3677   real_of_int_minus    reversed direction of equality (use [symmetric])
  3678   real_of_int_diff     reversed direction of equality (use [symmetric])
  3679   real_of_int_mult     reversed direction of equality (use [symmetric])
  3680 
  3681 * Theory RComplete: expanded support for floor and ceiling functions.
  3682 
  3683 * Theory Ln is new, with properties of the natural logarithm
  3684 
  3685 * Hyperreal: There is a new type constructor "star" for making
  3686 nonstandard types.  The old type names are now type synonyms:
  3687 
  3688   hypreal = real star
  3689   hypnat = nat star
  3690   hcomplex = complex star
  3691 
  3692 * Hyperreal: Many groups of similarly-defined constants have been
  3693 replaced by polymorphic versions (INCOMPATIBILITY):
  3694 
  3695   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3696 
  3697   starset      <-- starsetNat, starsetC
  3698   *s*          <-- *sNat*, *sc*
  3699   starset_n    <-- starsetNat_n, starsetC_n
  3700   *sn*         <-- *sNatn*, *scn*
  3701   InternalSets <-- InternalNatSets, InternalCSets
  3702 
  3703   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3704   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3705   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3706   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3707   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3708 
  3709 * Hyperreal: Many type-specific theorems have been removed in favor of
  3710 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3711 
  3712   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3713   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3714   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3715   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3716   right_minus <-- hypreal_add_minus
  3717   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3718   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3719   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3720   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3721   mult_1_right <-- hcomplex_mult_one_right
  3722   mult_zero_left <-- hcomplex_mult_zero_left
  3723   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3724   right_distrib <-- hypnat_add_mult_distrib2
  3725   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3726   right_inverse <-- hypreal_mult_inverse
  3727   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3728   order_refl <-- {hypreal,hypnat}_le_refl
  3729   order_trans <-- {hypreal,hypnat}_le_trans
  3730   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3731   order_less_le <-- {hypreal,hypnat}_less_le
  3732   linorder_linear <-- {hypreal,hypnat}_le_linear
  3733   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3734   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3735   add_nonneg_nonneg <-- hypreal_le_add_order
  3736 
  3737 * Hyperreal: Separate theorems having to do with type-specific
  3738 versions of constants have been merged into theorems that apply to the
  3739 new polymorphic constants (INCOMPATIBILITY):
  3740 
  3741   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3742   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3743   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3744   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3745   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3746   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3747   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3748   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3749   STAR_diff <-- {STAR,STARC}_diff
  3750   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3751     STARC_hcomplex_of_complex}_image_subset
  3752   starset_n_Un <-- starset{Nat,C}_n_Un
  3753   starset_n_Int <-- starset{Nat,C}_n_Int
  3754   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3755   starset_n_diff <-- starset{Nat,C}_n_diff
  3756   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3757   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3758   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3759   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3760   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3761   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3762   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3763   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3764   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3765   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3766   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3767   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3768   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3769   starfun_diff <-- starfun{C,RC,CR}_diff
  3770   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3771   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3772   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3773   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3774   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3775   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3776   starfun_Id <-- starfunC_Id
  3777   starfun_approx <-- starfun{Nat,CR}_approx
  3778   starfun_capprox <-- starfun{C,RC}_capprox
  3779   starfun_abs <-- starfunNat_rabs
  3780   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3781   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3782   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3783   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3784   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3785   starfun_add_approx <-- starfunCR_add_approx
  3786   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3787   starfun_divide <-- starfun{C,CR,RC}_divide
  3788   starfun_n <-- starfun{Nat,C}_n
  3789   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3790   starfun_n_add <-- starfun{Nat,C}_n_add
  3791   starfun_n_add_minus <-- starfunNat_n_add_minus
  3792   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3793   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3794   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3795 
  3796   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3797   star_n_minus <-- {hypreal,hcomplex}_minus
  3798   star_n_diff <-- {hypreal,hcomplex}_diff
  3799   star_n_mult <-- {hypreal,hcomplex}_mult
  3800   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3801   star_n_le <-- {hypreal,hypnat}_le
  3802   star_n_less <-- {hypreal,hypnat}_less
  3803   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3804   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3805   star_n_abs <-- hypreal_hrabs
  3806   star_n_divide <-- hcomplex_divide
  3807 
  3808   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3809   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3810   star_of_diff <-- hypreal_of_real_diff
  3811   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3812   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3813   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3814   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3815   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3816   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3817   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3818   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3819   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3820   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3821   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3822   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3823   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3824   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3825   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3826   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3827   star_of_power <-- hypreal_of_real_power
  3828   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3829 
  3830 * Hyperreal: new method "transfer" that implements the transfer
  3831 principle of nonstandard analysis. With a subgoal that mentions
  3832 nonstandard types like "'a star", the command "apply transfer"
  3833 replaces it with an equivalent one that mentions only standard types.
  3834 To be successful, all free variables must have standard types; non-
  3835 standard variables must have explicit universal quantifiers.
  3836 
  3837 * Hyperreal: A theory of Taylor series.
  3838 
  3839 
  3840 *** HOLCF ***
  3841 
  3842 * Discontinued special version of 'constdefs' (which used to support
  3843 continuous functions) in favor of the general Pure one with full
  3844 type-inference.
  3845 
  3846 * New simplification procedure for solving continuity conditions; it
  3847 is much faster on terms with many nested lambda abstractions (cubic
  3848 instead of exponential time).
  3849 
  3850 * New syntax for domain package: selector names are now optional.
  3851 Parentheses should be omitted unless argument is lazy, for example:
  3852 
  3853   domain 'a stream = cons "'a" (lazy "'a stream")
  3854 
  3855 * New command 'fixrec' for defining recursive functions with pattern
  3856 matching; defining multiple functions with mutual recursion is also
  3857 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3858 sinr, or any data constructor defined by the domain package. The given
  3859 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3860 syntax and examples.
  3861 
  3862 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3863 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3864 but the proof obligation additionally includes an admissibility
  3865 requirement. The packages generate instances of class cpo or pcpo,
  3866 with continuity and strictness theorems for Rep and Abs.
  3867 
  3868 * HOLCF: Many theorems have been renamed according to a more standard naming
  3869 scheme (INCOMPATIBILITY):
  3870 
  3871   foo_inject:  "foo$x = foo$y ==> x = y"
  3872   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3873   foo_less:    "(foo$x << foo$y) = (x << y)"
  3874   foo_strict:  "foo$UU = UU"
  3875   foo_defined: "... ==> foo$x ~= UU"
  3876   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3877 
  3878 
  3879 *** ZF ***
  3880 
  3881 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3882 including the First Isomorphism Theorem (on quotienting by the kernel
  3883 of a homomorphism).
  3884 
  3885 * ZF/Simplifier: install second copy of type solver that actually
  3886 makes use of TC rules declared to Isar proof contexts (or locales);
  3887 the old version is still required for ML proof scripts.
  3888 
  3889 
  3890 *** Cube ***
  3891 
  3892 * Converted to Isar theory format; use locales instead of axiomatic
  3893 theories.
  3894 
  3895 
  3896 *** ML ***
  3897 
  3898 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3899 for ||>, ||>>, |>>,
  3900 
  3901 * Pure/library.ML no longer defines its own option datatype, but uses
  3902 that of the SML basis, which has constructors NONE and SOME instead of
  3903 None and Some, as well as exception Option.Option instead of OPTION.
  3904 The functions the, if_none, is_some, is_none have been adapted
  3905 accordingly, while Option.map replaces apsome.
  3906 
  3907 * Pure/library.ML: the exception LIST has been given up in favour of
  3908 the standard exceptions Empty and Subscript, as well as
  3909 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3910 superceded by the standard hd and tl functions etc.
  3911 
  3912 A number of basic list functions are no longer exported to the ML
  3913 toplevel, as they are variants of predefined functions.  The following
  3914 suggests how one can translate existing code:
  3915 
  3916     rev_append xs ys = List.revAppend (xs, ys)
  3917     nth_elem (i, xs) = List.nth (xs, i)
  3918     last_elem xs = List.last xs
  3919     flat xss = List.concat xss
  3920     seq fs = List.app fs
  3921     partition P xs = List.partition P xs
  3922     mapfilter f xs = List.mapPartial f xs
  3923 
  3924 * Pure/library.ML: several combinators for linear functional
  3925 transformations, notably reverse application and composition:
  3926 
  3927   x |> f                f #> g
  3928   (x, y) |-> f          f #-> g
  3929 
  3930 * Pure/library.ML: introduced/changed precedence of infix operators:
  3931 
  3932   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3933   infix 2 ?;
  3934   infix 3 o oo ooo oooo;
  3935   infix 4 ~~ upto downto;
  3936 
  3937 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3938 infix operators.
  3939 
  3940 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3941 fold_map support linear functional transformations and nesting.  For
  3942 example:
  3943 
  3944   fold f [x1, ..., xN] y =
  3945     y |> f x1 |> ... |> f xN
  3946 
  3947   (fold o fold) f [xs1, ..., xsN] y =
  3948     y |> fold f xs1 |> ... |> fold f xsN
  3949 
  3950   fold f [x1, ..., xN] =
  3951     f x1 #> ... #> f xN
  3952 
  3953   (fold o fold) f [xs1, ..., xsN] =
  3954     fold f xs1 #> ... #> fold f xsN
  3955 
  3956 * Pure/library.ML: the following selectors on type 'a option are
  3957 available:
  3958 
  3959   the:               'a option -> 'a  (*partial*)
  3960   these:             'a option -> 'a  where 'a = 'b list
  3961   the_default: 'a -> 'a option -> 'a
  3962   the_list:          'a option -> 'a list
  3963 
  3964 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3965 basic operations for association lists, following natural argument
  3966 order; moreover the explicit equality predicate passed here avoids
  3967 potentially expensive polymorphic runtime equality checks.
  3968 The old functions may be expressed as follows:
  3969 
  3970   assoc = uncurry (AList.lookup (op =))
  3971   assocs = these oo AList.lookup (op =)
  3972   overwrite = uncurry (AList.update (op =)) o swap
  3973 
  3974 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3975 
  3976   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3977   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3978 
  3979 replacing make_keylist and keyfilter (occassionally used)
  3980 Naive rewrites:
  3981 
  3982   make_keylist = AList.make
  3983   keyfilter = AList.find (op =)
  3984 
  3985 * eq_fst and eq_snd now take explicit equality parameter, thus
  3986   avoiding eqtypes. Naive rewrites:
  3987 
  3988     eq_fst = eq_fst (op =)
  3989     eq_snd = eq_snd (op =)
  3990 
  3991 * Removed deprecated apl and apr (rarely used).
  3992   Naive rewrites:
  3993 
  3994     apl (n, op) =>>= curry op n
  3995     apr (op, m) =>>= fn n => op (n, m)
  3996 
  3997 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3998 provides a reasonably efficient light-weight implementation of sets as
  3999 lists.
  4000 
  4001 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4002 few new operations; existing lookup and update are now curried to
  4003 follow natural argument order (for use with fold etc.);
  4004 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4005 
  4006 * Pure/General: output via the Isabelle channels of
  4007 writeln/warning/error etc. is now passed through Output.output, with a
  4008 hook for arbitrary transformations depending on the print_mode
  4009 (cf. Output.add_mode -- the first active mode that provides a output
  4010 function wins).  Already formatted output may be embedded into further
  4011 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4012 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4013 accommodate easy composition of diagnostic messages etc.  Programmers
  4014 rarely need to care about Output.output or Output.raw at all, with
  4015 some notable exceptions: Output.output is required when bypassing the
  4016 standard channels (writeln etc.), or in token translations to produce
  4017 properly formatted results; Output.raw is required when capturing
  4018 already output material that will eventually be presented to the user
  4019 a second time.  For the default print mode, both Output.output and
  4020 Output.raw have no effect.
  4021 
  4022 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4023 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4024 cumulative results are displayed at the end of a batch session.
  4025 
  4026 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4027 replaced by File.platform_path and File.shell_path (with appropriate
  4028 hooks).  This provides a clean interface for unusual systems where the
  4029 internal and external process view of file names are different.
  4030 
  4031 * Pure: more efficient orders for basic syntactic entities: added
  4032 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4033 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4034 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4035 orders now -- potential INCOMPATIBILITY for code that depends on a
  4036 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4037 Library.sort_strings on result).
  4038 
  4039 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4040 fold_types traverse types/terms from left to right, observing natural
  4041 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4042 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4043 
  4044 * Pure: name spaces have been refined, with significant changes of the
  4045 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4046 to extern(_table).  The plain name entry path is superceded by a
  4047 general 'naming' context, which also includes the 'policy' to produce
  4048 a fully qualified name and external accesses of a fully qualified
  4049 name; NameSpace.extend is superceded by context dependent
  4050 Sign.declare_name.  Several theory and proof context operations modify
  4051 the naming context.  Especially note Theory.restore_naming and
  4052 ProofContext.restore_naming to get back to a sane state; note that
  4053 Theory.add_path is no longer sufficient to recover from
  4054 Theory.absolute_path in particular.
  4055 
  4056 * Pure: new flags short_names (default false) and unique_names
  4057 (default true) for controlling output of qualified names.  If
  4058 short_names is set, names are printed unqualified.  If unique_names is
  4059 reset, the name prefix is reduced to the minimum required to achieve
  4060 the original result when interning again, even if there is an overlap
  4061 with earlier declarations.
  4062 
  4063 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4064 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4065 (useful for printing error messages).  INCOMPATIBILITY.
  4066 
  4067 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4068 Theory.theory are now identified, referring to the universal
  4069 Context.theory (see Pure/context.ML).  Actual signature and theory
  4070 content is managed as theory data.  The old code and interfaces were
  4071 spread over many files and structures; the new arrangement introduces
  4072 considerable INCOMPATIBILITY to gain more clarity:
  4073 
  4074   Context -- theory management operations (name, identity, inclusion,
  4075     parents, ancestors, merge, etc.), plus generic theory data;
  4076 
  4077   Sign -- logical signature and syntax operations (declaring consts,
  4078     types, etc.), plus certify/read for common entities;
  4079 
  4080   Theory -- logical theory operations (stating axioms, definitions,
  4081     oracles), plus a copy of logical signature operations (consts,
  4082     types, etc.); also a few basic management operations (Theory.copy,
  4083     Theory.merge, etc.)
  4084 
  4085 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4086 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4087 for convenience -- they merely return the theory.
  4088 
  4089 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4090 
  4091 * Pure: the Isar proof context type is already defined early in Pure
  4092 as Context.proof (note that ProofContext.context and Proof.context are
  4093 aliases, where the latter is the preferred name).  This enables other
  4094 Isabelle components to refer to that type even before Isar is present.
  4095 
  4096 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4097 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4098 any of these kinds.  For example, Sign.intern typeK is now
  4099 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4100 Theory.hide_types.  Also note that former
  4101 Theory.hide_classes/types/consts are now
  4102 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4103 internalize their arguments!  INCOMPATIBILITY.
  4104 
  4105 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4106 datatype thmref (with constructors Name and NameSelection) instead of
  4107 plain string -- INCOMPATIBILITY;
  4108 
  4109 * Pure: cases produced by proof methods specify options, where NONE
  4110 means to remove case bindings -- INCOMPATIBILITY in
  4111 (RAW_)METHOD_CASES.
  4112 
  4113 * Pure: the following operations retrieve axioms or theorems from a
  4114 theory node or theory hierarchy, respectively:
  4115 
  4116   Theory.axioms_of: theory -> (string * term) list
  4117   Theory.all_axioms_of: theory -> (string * term) list
  4118   PureThy.thms_of: theory -> (string * thm) list
  4119   PureThy.all_thms_of: theory -> (string * thm) list
  4120 
  4121 * Pure: print_tac now outputs the goal through the trace channel.
  4122 
  4123 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4124 Reference Toplevel.debug (default false) controls detailed printing
  4125 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4126 controls execution profiling -- set to 1 for time and 2 for space
  4127 (both increase the runtime).
  4128 
  4129 * Isar session: The initial use of ROOT.ML is now always timed,
  4130 i.e. the log will show the actual process times, in contrast to the
  4131 elapsed wall-clock time that the outer shell wrapper produces.
  4132 
  4133 * Simplifier: improved handling of bound variables (nameless
  4134 representation, avoid allocating new strings).  Simprocs that invoke
  4135 the Simplifier recursively should use Simplifier.inherit_bounds to
  4136 avoid local name clashes.  Failure to do so produces warnings
  4137 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4138 for further details.
  4139 
  4140 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4141 bindings for all theorems stored within a given theory; this may help
  4142 in porting non-Isar theories to Isar ones, while keeping ML proof
  4143 scripts for the time being.
  4144 
  4145 * ML operator HTML.with_charset specifies the charset begin used for
  4146 generated HTML files.  For example:
  4147 
  4148   HTML.with_charset "utf-8" use_thy "Hebrew";
  4149   HTML.with_charset "utf-8" use_thy "Chinese";
  4150 
  4151 
  4152 *** System ***
  4153 
  4154 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4155 isabelle, isatool etc.).
  4156 
  4157 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4158 isatool doc, isatool mkdir, display_drafts etc.).
  4159 
  4160 * isatool usedir: option -f allows specification of the ML file to be
  4161 used by Isabelle; default is ROOT.ML.
  4162 
  4163 * New isatool version outputs the version identifier of the Isabelle
  4164 distribution being used.
  4165 
  4166 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4167 (containing Boolean satisfiability problems) into Isabelle/HOL
  4168 theories.
  4169 
  4170 
  4171 
  4172 New in Isabelle2004 (April 2004)
  4173 --------------------------------
  4174 
  4175 *** General ***
  4176 
  4177 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4178   Replaces linorder.ML.
  4179 
  4180 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4181   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4182   (\<a>...\<z>), are now considered normal letters, and can therefore
  4183   be used anywhere where an ASCII letter (a...zA...Z) has until
  4184   now. COMPATIBILITY: This obviously changes the parsing of some
  4185   terms, especially where a symbol has been used as a binder, say
  4186   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4187   as an identifier.  Fix it by inserting a space around former
  4188   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4189   existing theory and ML files.
  4190 
  4191 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4192 
  4193 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4194   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4195   a normal (but invisible) letter. For multiple letter subscripts repeat
  4196   \<^isub> like this: x\<^isub>1\<^isub>2.
  4197 
  4198 * Pure: There are now sub-/superscripts that can span more than one
  4199   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4200   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4201   superscript. The new control characters are not identifier parts.
  4202 
  4203 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4204   content of "..." to the latex file instead of \isacntrl... . The "..."
  4205   may consist of any printable characters excluding the end bracket >.
  4206 
  4207 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4208   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4209   declare constants "final", which prevents their being given a definition
  4210   later.  It is useful for constants whose behaviour is fixed axiomatically
  4211   rather than definitionally, such as the meta-logic connectives.
  4212 
  4213 * Pure: 'instance' now handles general arities with general sorts
  4214   (i.e. intersections of classes),
  4215 
  4216 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4217   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4218   It can be changed to alter the colors/layout of generated pages.
  4219 
  4220 
  4221 *** Isar ***
  4222 
  4223 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4224   cut_tac, subgoal_tac and thin_tac:
  4225   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4226     locales are no longer forced to write Isar proof scripts.
  4227     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4228     emulations.
  4229   - INCOMPATIBILITY: names of variables to be instantiated may no
  4230     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4231     This is consistent with the instantiation attribute "where".
  4232 
  4233 * Attributes "where" and "of":
  4234   - Now take type variables of instantiated theorem into account when reading
  4235     the instantiation string.  This fixes a bug that caused instantiated
  4236     theorems to have too special types in some circumstances.
  4237   - "where" permits explicit instantiations of type variables.
  4238 
  4239 * Calculation commands "moreover" and "also" no longer interfere with
  4240   current facts ("this"), admitting arbitrary combinations with "then"
  4241   and derived forms.
  4242 
  4243 * Locales:
  4244   - Goal statements involving the context element "includes" no longer
  4245     generate theorems with internal delta predicates (those ending on
  4246     "_axioms") in the premise.
  4247     Resolve particular premise with <locale>.intro to obtain old form.
  4248   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4249     specification and "includes" elements in goal statement.
  4250   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4251     [intro?] and [elim?] (respectively) by default.
  4252   - Experimental command for instantiation of locales in proof contexts:
  4253         instantiate <label>[<attrs>]: <loc>
  4254     Instantiates locale <loc> and adds all its theorems to the current context
  4255     taking into account their attributes.  Label and attrs are optional
  4256     modifiers, like in theorem declarations.  If present, names of
  4257     instantiated theorems are qualified with <label>, and the attributes
  4258     <attrs> are applied after any attributes these theorems might have already.
  4259       If the locale has assumptions, a chained fact of the form
  4260     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4261     are derived.  The command does not support old-style locales declared
  4262     with "locale (open)".
  4263       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4264 
  4265 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4266   (Isar) contexts.
  4267 
  4268 
  4269 *** HOL ***
  4270 
  4271 * Proof import: new image HOL4 contains the imported library from
  4272   the HOL4 system with about 2500 theorems. It is imported by
  4273   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4274   can be used like any other Isabelle image.  See
  4275   HOL/Import/HOL/README for more information.
  4276 
  4277 * Simplifier:
  4278   - Much improved handling of linear and partial orders.
  4279     Reasoners for linear and partial orders are set up for type classes
  4280     "linorder" and "order" respectively, and are added to the default simpset
  4281     as solvers.  This means that the simplifier can build transitivity chains
  4282     to solve goals from the assumptions.
  4283   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4284     of blast or auto after simplification become unnecessary because the goal
  4285     is solved by simplification already.
  4286 
  4287 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4288     all proved in axiomatic type classes for semirings, rings and fields.
  4289 
  4290 * Numerics:
  4291   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4292     now formalized using the Ring_and_Field theory mentioned above.
  4293   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4294     than before, because now they are set up once in a generic manner.
  4295   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4296     Look for the general versions in Ring_and_Field (and Power if they concern
  4297     exponentiation).
  4298 
  4299 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4300 
  4301 * Records:
  4302   - Record types are now by default printed with their type abbreviation
  4303     instead of the list of all field types. This can be configured via
  4304     the reference "print_record_type_abbr".
  4305   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4306     (not enabled by default).
  4307   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4308     EX x. x = sel r to True (not enabled by default).
  4309   - Tactic "record_split_simp_tac" to split and simplify records added.
  4310 
  4311 * 'specification' command added, allowing for definition by
  4312   specification.  There is also an 'ax_specification' command that
  4313   introduces the new constants axiomatically.
  4314 
  4315 * arith(_tac) is now able to generate counterexamples for reals as well.
  4316 
  4317 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4318 
  4319 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4320   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4321 
  4322 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4323   matrix theory to linear programming.
  4324 
  4325 * Unions and Intersections:
  4326   The latex output syntax of UN and INT has been changed
  4327   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4328   i.e. the index formulae has become a subscript.
  4329   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4330 
  4331 * Unions and Intersections over Intervals:
  4332   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4333   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4334   like in normal math, and corresponding versions for < and for intersection.
  4335 
  4336 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4337   lexicographic dictonary ordering has been added as "lexord".
  4338 
  4339 * ML: the legacy theory structures Int and List have been removed. They had
  4340   conflicted with ML Basis Library structures having the same names.
  4341 
  4342 * 'refute' command added to search for (finite) countermodels.  Only works
  4343   for a fragment of HOL.  The installation of an external SAT solver is
  4344   highly recommended.  See "HOL/Refute.thy" for details.
  4345 
  4346 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4347   formulae under an assignment of free variables to random values.
  4348   In contrast to 'refute', it can deal with inductive datatypes,
  4349   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4350   for examples.
  4351 
  4352 
  4353 *** HOLCF ***
  4354 
  4355 * Streams now come with concatenation and are part of the HOLCF image
  4356 
  4357 
  4358 
  4359 New in Isabelle2003 (May 2003)
  4360 ------------------------------
  4361 
  4362 *** General ***
  4363 
  4364 * Provers/simplifier:
  4365 
  4366   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4367     Assumptions are now subject to complete mutual simplification,
  4368     not just from left to right. The simplifier now preserves
  4369     the order of assumptions.
  4370 
  4371     Potential INCOMPATIBILITY:
  4372 
  4373     -- simp sometimes diverges where the old version did
  4374        not, e.g. invoking simp on the goal
  4375 
  4376         [| P (f x); y = x; f x = f y |] ==> Q
  4377 
  4378        now gives rise to the infinite reduction sequence
  4379 
  4380         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4381 
  4382        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4383        kind of problem.
  4384 
  4385     -- Tactics combining classical reasoner and simplification (such as auto)
  4386        are also affected by this change, because many of them rely on
  4387        simp. They may sometimes diverge as well or yield a different numbers
  4388        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4389        in case of problems. Sometimes subsequent calls to the classical
  4390        reasoner will fail because a preceeding call to the simplifier too
  4391        eagerly simplified the goal, e.g. deleted redundant premises.
  4392 
  4393   - The simplifier trace now shows the names of the applied rewrite rules
  4394 
  4395   - You can limit the number of recursive invocations of the simplifier
  4396     during conditional rewriting (where the simplifie tries to solve the
  4397     conditions before applying the rewrite rule):
  4398     ML "simp_depth_limit := n"
  4399     where n is an integer. Thus you can force termination where previously
  4400     the simplifier would diverge.
  4401 
  4402   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4403 
  4404   - No longer aborts on failed congruence proof.  Instead, the
  4405     congruence is ignored.
  4406 
  4407 * Pure: New generic framework for extracting programs from constructive
  4408   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4409   as HOL/Extraction for some case studies.
  4410 
  4411 * Pure: The main goal of the proof state is no longer shown by default, only
  4412 the subgoals. This behaviour is controlled by a new flag.
  4413    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4414 (ML: Proof.show_main_goal).
  4415 
  4416 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4417 rules whose conclusion matches subgoal 1:
  4418       PG menu: Isabelle/Isar -> Show me -> matching rules
  4419 The rules are ordered by how closely they match the subgoal.
  4420 In particular, rules that solve a subgoal outright are displayed first
  4421 (or rather last, the way they are printed).
  4422 (ML: ProofGeneral.print_intros())
  4423 
  4424 * Pure: New flag trace_unify_fail causes unification to print
  4425 diagnostic information (PG: in trace buffer) when it fails. This is
  4426 useful for figuring out why single step proofs like rule, erule or
  4427 assumption failed.
  4428 
  4429 * Pure: Locale specifications now produce predicate definitions
  4430 according to the body of text (covering assumptions modulo local
  4431 definitions); predicate "loc_axioms" covers newly introduced text,
  4432 while "loc" is cumulative wrt. all included locale expressions; the
  4433 latter view is presented only on export into the global theory
  4434 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4435 on the old view without predicates;
  4436 
  4437 * Pure: predefined locales "var" and "struct" are useful for sharing
  4438 parameters (as in CASL, for example); just specify something like
  4439 ``var x + var y + struct M'' as import;
  4440 
  4441 * Pure: improved thms_containing: proper indexing of facts instead of
  4442 raw theorems; check validity of results wrt. current name space;
  4443 include local facts of proof configuration (also covers active
  4444 locales), cover fixed variables in index; may use "_" in term
  4445 specification; an optional limit for the number of printed facts may
  4446 be given (the default is 40);
  4447 
  4448 * Pure: disallow duplicate fact bindings within new-style theory files
  4449 (batch-mode only);
  4450 
  4451 * Provers: improved induct method: assumptions introduced by case
  4452 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4453 the goal statement); "foo" still refers to all facts collectively;
  4454 
  4455 * Provers: the function blast.overloaded has been removed: all constants
  4456 are regarded as potentially overloaded, which improves robustness in exchange
  4457 for slight decrease in efficiency;
  4458 
  4459 * Provers/linorder: New generic prover for transitivity reasoning over
  4460 linear orders.  Note: this prover is not efficient!
  4461 
  4462 * Isar: preview of problems to finish 'show' now produce an error
  4463 rather than just a warning (in interactive mode);
  4464 
  4465 
  4466 *** HOL ***
  4467 
  4468 * arith(_tac)
  4469 
  4470  - Produces a counter example if it cannot prove a goal.
  4471    Note that the counter example may be spurious if the goal is not a formula
  4472    of quantifier-free linear arithmetic.
  4473    In ProofGeneral the counter example appears in the trace buffer.
  4474 
  4475  - Knows about div k and mod k where k is a numeral of type nat or int.
  4476 
  4477  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4478    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4479    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4480 
  4481 * simp's arithmetic capabilities have been enhanced a bit: it now
  4482 takes ~= in premises into account (by performing a case split);
  4483 
  4484 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4485 are distributed over a sum of terms;
  4486 
  4487 * New tactic "trans_tac" and method "trans" instantiate
  4488 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4489 "<=", "<" and "=").
  4490 
  4491 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4492 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4493 
  4494 * 'typedef' command has new option "open" to suppress the set
  4495 definition;
  4496 
  4497 * functions Min and Max on finite sets have been introduced (theory
  4498 Finite_Set);
  4499 
  4500 * attribute [symmetric] now works for relations as well; it turns
  4501 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4502 
  4503 * induct over a !!-quantified statement (say !!x1..xn):
  4504   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4505 
  4506 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4507 %x. None. Warning: empty_def now refers to the previously hidden definition
  4508 of the empty set.
  4509 
  4510 * Algebra: formalization of classical algebra.  Intended as base for
  4511 any algebraic development in Isabelle.  Currently covers group theory
  4512 (up to Sylow's theorem) and ring theory (Universal Property of
  4513 Univariate Polynomials).  Contributions welcome;
  4514 
  4515 * GroupTheory: deleted, since its material has been moved to Algebra;
  4516 
  4517 * Complex: new directory of the complex numbers with numeric constants,
  4518 nonstandard complex numbers, and some complex analysis, standard and
  4519 nonstandard (Jacques Fleuriot);
  4520 
  4521 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4522 
  4523 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4524 Fleuriot);
  4525 
  4526 * Real/HahnBanach: updated and adapted to locales;
  4527 
  4528 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4529 Gray and Kramer);
  4530 
  4531 * UNITY: added the Meier-Sanders theory of progress sets;
  4532 
  4533 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4534 as abstract algorithms, instantiated to the JVM;
  4535 
  4536 * Bali: Java source language formalization. Type system, operational
  4537 semantics, axiomatic semantics. Supported language features:
  4538 classes, interfaces, objects,virtual methods, static methods,
  4539 static/instance fields, arrays, access modifiers, definite
  4540 assignment, exceptions.
  4541 
  4542 
  4543 *** ZF ***
  4544 
  4545 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4546 universe, etc.);
  4547 
  4548 * Main ZF: virtually all theories converted to new-style format;
  4549 
  4550 
  4551 *** ML ***
  4552 
  4553 * Pure: Tactic.prove provides sane interface for internal proofs;
  4554 omits the infamous "standard" operation, so this is more appropriate
  4555 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4556 
  4557 * Pure: improved error reporting of simprocs;
  4558 
  4559 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4560 up simprocs;
  4561 
  4562 
  4563 *** Document preparation ***
  4564 
  4565 * uses \par instead of \\ for line breaks in theory text. This may
  4566 shift some page breaks in large documents. To get the old behaviour
  4567 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4568 
  4569 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4570 other packages
  4571 
  4572 * \<euro> now needs package babel/greek instead of marvosym (which
  4573 broke \Rightarrow)
  4574 
  4575 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4576 textcomp package)
  4577 
  4578 
  4579 
  4580 New in Isabelle2002 (March 2002)
  4581 --------------------------------
  4582 
  4583 *** Document preparation ***
  4584 
  4585 * greatly simplified document preparation setup, including more
  4586 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4587 instructive isatool mkdir; users should basically be able to get
  4588 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4589 users may run a separate document processing stage manually like this:
  4590 "isatool usedir -D output HOL Test && isatool document Test/output";
  4591 
  4592 * theory dependency graph may now be incorporated into documents;
  4593 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4594 with \includegraphics of LaTeX;
  4595 
  4596 * proper spacing of consecutive markup elements, especially text
  4597 blocks after section headings;
  4598 
  4599 * support bold style (for single symbols only), input syntax is like
  4600 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4601 
  4602 * \<bullet> is now output as bold \cdot by default, which looks much
  4603 better in printed text;
  4604 
  4605 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4606 note that these symbols are currently unavailable in Proof General /
  4607 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4608 
  4609 * isatool latex no longer depends on changed TEXINPUTS, instead
  4610 isatool document copies the Isabelle style files to the target
  4611 location;
  4612 
  4613 
  4614 *** Isar ***
  4615 
  4616 * Pure/Provers: improved proof by cases and induction;
  4617   - 'case' command admits impromptu naming of parameters (such as
  4618     "case (Suc n)");
  4619   - 'induct' method divinates rule instantiation from the inductive
  4620     claim; no longer requires excessive ?P bindings for proper
  4621     instantiation of cases;
  4622   - 'induct' method properly enumerates all possibilities of set/type
  4623     rules; as a consequence facts may be also passed through *type*
  4624     rules without further ado;
  4625   - 'induct' method now derives symbolic cases from the *rulified*
  4626     rule (before it used to rulify cases stemming from the internal
  4627     atomized version); this means that the context of a non-atomic
  4628     statement becomes is included in the hypothesis, avoiding the
  4629     slightly cumbersome show "PROP ?case" form;
  4630   - 'induct' may now use elim-style induction rules without chaining
  4631     facts, using ``missing'' premises from the goal state; this allows
  4632     rules stemming from inductive sets to be applied in unstructured
  4633     scripts, while still benefitting from proper handling of non-atomic
  4634     statements; NB: major inductive premises need to be put first, all
  4635     the rest of the goal is passed through the induction;
  4636   - 'induct' proper support for mutual induction involving non-atomic
  4637     rule statements (uses the new concept of simultaneous goals, see
  4638     below);
  4639   - append all possible rule selections, but only use the first
  4640     success (no backtracking);
  4641   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4642   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4643   - added 'print_induct_rules' (covered by help item in recent Proof
  4644     General versions);
  4645   - moved induct/cases attributes to Pure, methods to Provers;
  4646   - generic method setup instantiated for FOL and HOL;
  4647 
  4648 * Pure: support multiple simultaneous goal statements, for example
  4649 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4650 meta-level mechanism, this acts as if several individual goals had
  4651 been stated separately; in particular common proof methods need to be
  4652 repeated in order to cover all claims; note that a single elimination
  4653 step is *not* sufficient to establish the two conjunctions, so this
  4654 fails:
  4655 
  4656   assume "A & B" then have A and B ..   (*".." fails*)
  4657 
  4658 better use "obtain" in situations as above; alternative refer to
  4659 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4660 
  4661 * Pure: proper integration with ``locales''; unlike the original
  4662 version by Florian Kammller, Isar locales package high-level proof
  4663 contexts rather than raw logical ones (e.g. we admit to include
  4664 attributes everywhere); operations on locales include merge and
  4665 rename; support for implicit arguments (``structures''); simultaneous
  4666 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4667 some examples;
  4668 
  4669 * Pure: the following commands have been ``localized'', supporting a
  4670 target locale specification "(in name)": 'lemma', 'theorem',
  4671 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4672 stored both within the locale and at the theory level (exported and
  4673 qualified by the locale name);
  4674 
  4675 * Pure: theory goals may now be specified in ``long'' form, with
  4676 ad-hoc contexts consisting of arbitrary locale elements. for example
  4677 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4678 definitions may be given, too); the result is a meta-level rule with
  4679 the context elements being discharged in the obvious way;
  4680 
  4681 * Pure: new proof command 'using' allows to augment currently used
  4682 facts after a goal statement ('using' is syntactically analogous to
  4683 'apply', but acts on the goal's facts only); this allows chained facts
  4684 to be separated into parts given before and after a claim, as in
  4685 ``from a and b have C using d and e <proof>'';
  4686 
  4687 * Pure: renamed "antecedent" case to "rule_context";
  4688 
  4689 * Pure: new 'judgment' command records explicit information about the
  4690 object-logic embedding (used by several tools internally); no longer
  4691 use hard-wired "Trueprop";
  4692 
  4693 * Pure: added 'corollary' command;
  4694 
  4695 * Pure: fixed 'token_translation' command;
  4696 
  4697 * Pure: removed obsolete 'exported' attribute;
  4698 
  4699 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4700 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4701 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4702 
  4703 * Pure: method 'atomize' presents local goal premises as object-level
  4704 statements (atomic meta-level propositions); setup controlled via
  4705 rewrite rules declarations of 'atomize' attribute; example
  4706 application: 'induct' method with proper rule statements in improper
  4707 proof *scripts*;
  4708 
  4709 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4710 now consider the syntactic context of assumptions, giving a better
  4711 chance to get type-inference of the arguments right (this is
  4712 especially important for locales);
  4713 
  4714 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4715 mode;
  4716 
  4717 * Pure/obtain: the formal conclusion "thesis", being marked as
  4718 ``internal'', may no longer be reference directly in the text;
  4719 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4720 situations;
  4721 
  4722 * Pure: generic 'sym' attribute which declares a rule both as pure
  4723 'elim?' and for the 'symmetric' operation;
  4724 
  4725 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4726 text; the fixed correlation with particular command syntax has been
  4727 discontinued;
  4728 
  4729 * Pure: new method 'rules' is particularly well-suited for proof
  4730 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4731 but often produces more compact proof terms with less detours;
  4732 
  4733 * Pure/Provers/classical: simplified integration with pure rule
  4734 attributes and methods; the classical "intro?/elim?/dest?"
  4735 declarations coincide with the pure ones; the "rule" method no longer
  4736 includes classically swapped intros; "intro" and "elim" methods no
  4737 longer pick rules from the context; also got rid of ML declarations
  4738 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4739 INCOMPATIBILITY;
  4740 
  4741 * Provers/classical: attribute 'swapped' produces classical inversions
  4742 of introduction rules;
  4743 
  4744 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4745 rules instead of full simplifier context; 'iff' attribute handles
  4746 conditional rules;
  4747 
  4748 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4749 
  4750 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4751 "(permissive)" option to recover old behavior;
  4752 
  4753 * HOL: 'inductive' no longer features separate (collective) attributes
  4754 for 'intros' (was found too confusing);
  4755 
  4756 * HOL: properly declared induction rules less_induct and
  4757 wf_induct_rule;
  4758 
  4759 
  4760 *** HOL ***
  4761 
  4762 * HOL: moved over to sane numeral syntax; the new policy is as
  4763 follows:
  4764 
  4765   - 0 and 1 are polymorphic constants, which are defined on any
  4766   numeric type (nat, int, real etc.);
  4767 
  4768   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4769   binary representation internally;
  4770 
  4771   - type nat has special constructor Suc, and generally prefers Suc 0
  4772   over 1::nat and Suc (Suc 0) over 2::nat;
  4773 
  4774 This change may cause significant problems of INCOMPATIBILITY; here
  4775 are some hints on converting existing sources:
  4776 
  4777   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4778   entities, so expressions involving "-" (unary or binary minus) need
  4779   to be spaced properly;
  4780 
  4781   - existing occurrences of "1" may need to be constraint "1::nat" or
  4782   even replaced by Suc 0; similar for old "2";
  4783 
  4784   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4785 
  4786   - remove all special provisions on numerals in proofs;
  4787 
  4788 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4789 representation (depends on bin_arith_simps in the default context);
  4790 
  4791 * HOL: symbolic syntax for x^2 (numeral 2);
  4792 
  4793 * HOL: the class of all HOL types is now called "type" rather than
  4794 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4795 in axclass/classes, instance/arities, and (usually rare) occurrences
  4796 in typings (of consts etc.); internally the class is called
  4797 "HOL.type", ML programs should refer to HOLogic.typeS;
  4798 
  4799 * HOL/record package improvements:
  4800   - new derived operations "fields" to build a partial record section,
  4801     "extend" to promote a fixed record to a record scheme, and
  4802     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4803     declared as simp by default;
  4804   - shared operations ("more", "fields", etc.) now need to be always
  4805     qualified) --- potential INCOMPATIBILITY;
  4806   - removed "make_scheme" operations (use "make" with "extend") --
  4807     INCOMPATIBILITY;
  4808   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4809   - provides cases/induct rules for use with corresponding Isar
  4810     methods (for concrete records, record schemes, concrete more
  4811     parts, and schematic more parts -- in that order);
  4812   - internal definitions directly based on a light-weight abstract
  4813     theory of product types over typedef rather than datatype;
  4814 
  4815 * HOL: generic code generator for generating executable ML code from
  4816 specifications; specific support for HOL constructs such as inductive
  4817 datatypes and sets, as well as recursive functions; can be invoked
  4818 via 'generate_code' theory section;
  4819 
  4820 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4821 
  4822 * HOL: consolidated and renamed several theories.  In particular:
  4823         Ord.thy has been absorbed into HOL.thy
  4824         String.thy has been absorbed into List.thy
  4825 
  4826 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4827 (beware of argument permutation!);
  4828 
  4829 * HOL: linorder_less_split superseded by linorder_cases;
  4830 
  4831 * HOL/List: "nodups" renamed to "distinct";
  4832 
  4833 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4834 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4835   - Ex_def has changed, now need to use some_eq_ex
  4836 
  4837 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4838 in this (rare) case use:
  4839 
  4840   delSWrapper "split_all_tac"
  4841   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4842 
  4843 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4844 MAY FAIL;
  4845 
  4846 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4847 Isabelle's type classes, ^ on functions and relations has too general
  4848 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4849 necessary to attach explicit type constraints;
  4850 
  4851 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4852 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4853 renamed accordingly (eg "compI" -> "rel_compI").
  4854 
  4855 * HOL: syntax translations now work properly with numerals and records
  4856 expressions;
  4857 
  4858 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4859 of "lam" -- INCOMPATIBILITY;
  4860 
  4861 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4862 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4863 renamed "Product_Type.unit";
  4864 
  4865 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4866 
  4867 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4868 the "cases" method);
  4869 
  4870 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4871 Florian Kammller);
  4872 
  4873 * HOL/IMP: updated and converted to new-style theory format; several
  4874 parts turned into readable document, with proper Isar proof texts and
  4875 some explanations (by Gerwin Klein);
  4876 
  4877 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4878 
  4879 * HOL-Hyperreal is now a logic image;
  4880 
  4881 
  4882 *** HOLCF ***
  4883 
  4884 * Isar: consts/constdefs supports mixfix syntax for continuous
  4885 operations;
  4886 
  4887 * Isar: domain package adapted to new-style theory format, e.g. see
  4888 HOLCF/ex/Dnat.thy;
  4889 
  4890 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4891 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4892 lift.induct_tac, always use UU instead of Undef;
  4893 
  4894 * HOLCF/IMP: updated and converted to new-style theory;
  4895 
  4896 
  4897 *** ZF ***
  4898 
  4899 * Isar: proper integration of logic-specific tools and packages,
  4900 including theory commands '(co)inductive', '(co)datatype',
  4901 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4902 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4903 
  4904 * theory Main no longer includes AC; for the Axiom of Choice, base
  4905 your theory on Main_ZFC;
  4906 
  4907 * the integer library now covers quotients and remainders, with many
  4908 laws relating division to addition, multiplication, etc.;
  4909 
  4910 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4911 typeless version of the formalism;
  4912 
  4913 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4914 format;
  4915 
  4916 * ZF/Induct: new directory for examples of inductive definitions,
  4917 including theory Multiset for multiset orderings; converted to
  4918 new-style theory format;
  4919 
  4920 * ZF: many new theorems about lists, ordinals, etc.;
  4921 
  4922 
  4923 *** General ***
  4924 
  4925 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4926 variable proof controls level of detail: 0 = no proofs (only oracle
  4927 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4928 also ref manual for further ML interfaces;
  4929 
  4930 * Pure/axclass: removed obsolete ML interface
  4931 goal_subclass/goal_arity;
  4932 
  4933 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4934 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4935 separate tokens, so expressions involving minus need to be spaced
  4936 properly;
  4937 
  4938 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4939 rather than "infixl" or "infixr";
  4940 
  4941 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4942 sort constraint specifications in type inference; e.g. "x::_::foo"
  4943 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4944 type variable);
  4945 
  4946 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4947 control output of nested => (types); the default behavior is
  4948 "type_brackets";
  4949 
  4950 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4951 tokens into AST constants;
  4952 
  4953 * Pure/syntax: prefer later declarations of translations and print
  4954 translation functions; potential INCOMPATIBILITY: need to reverse
  4955 multiple declarations for same syntax element constant;
  4956 
  4957 * Pure/show_hyps reset by default (in accordance to existing Isar
  4958 practice);
  4959 
  4960 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4961 addSafter;
  4962 
  4963 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4964 as well;
  4965 
  4966 * system: tested support for MacOS X; should be able to get Isabelle +
  4967 Proof General to work in a plain Terminal after installing Poly/ML
  4968 (e.g. from the Isabelle distribution area) and GNU bash alone
  4969 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4970 support requires further installations, e.g. from
  4971 http://fink.sourceforge.net/);
  4972 
  4973 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4974 
  4975 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4976 of 40 MB), cf. ML_OPTIONS;
  4977 
  4978 * system: Proof General keywords specification is now part of the
  4979 Isabelle distribution (see etc/isar-keywords.el);
  4980 
  4981 * system: support for persistent Proof General sessions (refrain from
  4982 outdating all loaded theories on startup); user may create writable
  4983 logic images like this: ``isabelle -q HOL Test'';
  4984 
  4985 * system: smart selection of Isabelle process versus Isabelle
  4986 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4987 run both "isabelle" and "Isabelle" even if file names are badly
  4988 damaged (executable inspects the case of the first letter of its own
  4989 name); added separate "isabelle-process" and "isabelle-interface";
  4990 
  4991 * system: refrain from any attempt at filtering input streams; no
  4992 longer support ``8bit'' encoding of old isabelle font, instead proper
  4993 iso-latin characters may now be used; the related isatools
  4994 "symbolinput" and "nonascii" have disappeared as well;
  4995 
  4996 * system: removed old "xterm" interface (the print modes "xterm" and
  4997 "xterm_color" are still available for direct use in a suitable
  4998 terminal);
  4999 
  5000 
  5001 
  5002 New in Isabelle99-2 (February 2001)
  5003 -----------------------------------
  5004 
  5005 *** Overview of INCOMPATIBILITIES ***
  5006 
  5007 * HOL: please note that theories in the Library and elsewhere often use the
  5008 new-style (Isar) format; to refer to their theorems in an ML script you must
  5009 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5010 
  5011 * HOL: inductive package no longer splits induction rule aggressively,
  5012 but only as far as specified by the introductions given; the old
  5013 format may be recovered via ML function complete_split_rule or attribute
  5014 'split_rule (complete)';
  5015 
  5016 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5017 gfp_Tarski to gfp_unfold;
  5018 
  5019 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5020 
  5021 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5022 relation); infix "^^" has been renamed "``"; infix "``" has been
  5023 renamed "`"; "univalent" has been renamed "single_valued";
  5024 
  5025 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5026 operation;
  5027 
  5028 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5029 
  5030 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5031 
  5032 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5033 consequence, it is no longer monotonic wrt. the local goal context
  5034 (which is now passed through the inductive cases);
  5035 
  5036 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5037 \<gg> to \<ggreater>;
  5038 
  5039 
  5040 *** Document preparation ***
  5041 
  5042 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5043 available: are "it" for near math-mode best-style output, "sl" for
  5044 slanted text style, and "tt" for plain type-writer; if no
  5045 \isabellestyle command is given, output is according to slanted
  5046 type-writer);
  5047 
  5048 * support sub/super scripts (for single symbols only), input syntax is
  5049 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5050 
  5051 * some more standard symbols; see Appendix A of the system manual for
  5052 the complete list of symbols defined in isabellesym.sty;
  5053 
  5054 * improved isabelle style files; more abstract symbol implementation
  5055 (should now use \isamath{...} and \isatext{...} in custom symbol
  5056 definitions);
  5057 
  5058 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5059 state; Note that presentation of goal states does not conform to
  5060 actual human-readable proof documents.  Please do not include goal
  5061 states into document output unless you really know what you are doing!
  5062 
  5063 * proper indentation of antiquoted output with proportional LaTeX
  5064 fonts;
  5065 
  5066 * no_document ML operator temporarily disables LaTeX document
  5067 generation;
  5068 
  5069 * isatool unsymbolize tunes sources for plain ASCII communication;
  5070 
  5071 
  5072 *** Isar ***
  5073 
  5074 * Pure: Isar now suffers initial goal statements to contain unbound
  5075 schematic variables (this does not conform to actual readable proof
  5076 documents, due to unpredictable outcome and non-compositional proof
  5077 checking); users who know what they are doing may use schematic goals
  5078 for Prolog-style synthesis of proven results;
  5079 
  5080 * Pure: assumption method (an implicit finishing) now handles actual
  5081 rules as well;
  5082 
  5083 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5084 initial goal, declare "that" only as Pure intro (only for single
  5085 steps); the "that" rule assumption may now be involved in implicit
  5086 finishing, thus ".." becomes a feasible for trivial obtains;
  5087 
  5088 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5089 instance proofs may be performed by "..";
  5090 
  5091 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5092 statements as well;
  5093 
  5094 * Pure: more robust selection of calculational rules;
  5095 
  5096 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5097 rule (as well as the assumption rule);
  5098 
  5099 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5100 lemmas, using the graph browser tool;
  5101 
  5102 * Pure: predict failure of "show" in interactive mode;
  5103 
  5104 * Pure: 'thms_containing' now takes actual terms as arguments;
  5105 
  5106 * HOL: improved method 'induct' --- now handles non-atomic goals
  5107 (potential INCOMPATIBILITY); tuned error handling;
  5108 
  5109 * HOL: cases and induct rules now provide explicit hints about the
  5110 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5111 any remaining facts are inserted into the goal verbatim;
  5112 
  5113 * HOL: local contexts (aka cases) may now contain term bindings as
  5114 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5115 the result to be shown in each case;
  5116 
  5117 * HOL: added 'recdef_tc' command;
  5118 
  5119 * isatool convert assists in eliminating legacy ML scripts;
  5120 
  5121 
  5122 *** HOL ***
  5123 
  5124 * HOL/Library: a collection of generic theories to be used together
  5125 with main HOL; the theory loader path already includes this directory
  5126 by default; the following existing theories have been moved here:
  5127 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5128 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5129 
  5130 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5131 modelling and verification task performed in Isabelle/HOL +
  5132 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5133 
  5134 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5135 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5136 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5137 'domain', this makes the theory consistent with mathematical
  5138 literature;
  5139 
  5140 * HOL basics: added overloaded operations "inverse" and "divide"
  5141 (infix "/"), syntax for generic "abs" operation, generic summation
  5142 operator \<Sum>;
  5143 
  5144 * HOL/typedef: simplified package, provide more useful rules (see also
  5145 HOL/subset.thy);
  5146 
  5147 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5148 now expressed as a proper nested rule (old-style tactic scripts may
  5149 require atomize_strip_tac to cope with non-atomic premises);
  5150 
  5151 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5152 to "split_conv" (old name still available for compatibility);
  5153 
  5154 * HOL: improved concrete syntax for strings (e.g. allows translation
  5155 rules with string literals);
  5156 
  5157 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5158  and Fleuriot's mechanization of analysis, including the transcendental
  5159  functions for the reals;
  5160 
  5161 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5162 
  5163 
  5164 *** CTT ***
  5165 
  5166 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5167 "lam" is displayed as TWO lambda-symbols
  5168 
  5169 * CTT: theory Main now available, containing everything (that is, Bool
  5170 and Arith);
  5171 
  5172 
  5173 *** General ***
  5174 
  5175 * Pure: the Simplifier has been implemented properly as a derived rule
  5176 outside of the actual kernel (at last!); the overall performance
  5177 penalty in practical applications is about 50%, while reliability of
  5178 the Isabelle inference kernel has been greatly improved;
  5179 
  5180 * print modes "brackets" and "no_brackets" control output of nested =>
  5181 (types) and ==> (props); the default behaviour is "brackets";
  5182 
  5183 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5184 as assumptions as well;
  5185 
  5186 * system: support Poly/ML 4.0;
  5187 
  5188 * system: isatool install handles KDE version 1 or 2;
  5189 
  5190 
  5191 
  5192 New in Isabelle99-1 (October 2000)
  5193 ----------------------------------
  5194 
  5195 *** Overview of INCOMPATIBILITIES ***
  5196 
  5197 * HOL: simplification of natural numbers is much changed; to partly
  5198 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5199 issue the following ML commands:
  5200 
  5201   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5202   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5203 
  5204 * HOL: simplification no longer dives into case-expressions; this is
  5205 controlled by "t.weak_case_cong" for each datatype t;
  5206 
  5207 * HOL: nat_less_induct renamed to less_induct;
  5208 
  5209 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5210 fixsome to patch .thy and .ML sources automatically;
  5211 
  5212   select_equality  -> some_equality
  5213   select_eq_Ex     -> some_eq_ex
  5214   selectI2EX       -> someI2_ex
  5215   selectI2         -> someI2
  5216   selectI          -> someI
  5217   select1_equality -> some1_equality
  5218   Eps_sym_eq       -> some_sym_eq_trivial
  5219   Eps_eq           -> some_eq_trivial
  5220 
  5221 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5222 
  5223 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5224 instead);
  5225 
  5226 * HOL: the recursion equations generated by 'recdef' are now called
  5227 f.simps instead of f.rules;
  5228 
  5229 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5230 
  5231 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5232 sometimes be needed;
  5233 
  5234 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5235 
  5236 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5237 
  5238 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5239 product is now "<*>" instead of "Times"; the lexicographic product is
  5240 now "<*lex*>" instead of "**";
  5241 
  5242 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5243 of main HOL, but was unused); better use HOL's datatype package;
  5244 
  5245 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5246 the old syntax may be recovered as follows:
  5247 
  5248   syntax (symbols)
  5249     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5250       (infixl "\\<oplus>" 100)
  5251 
  5252 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5253 
  5254 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5255 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5256 internally;
  5257 
  5258 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5259 changed from A/r to A//r;
  5260 
  5261 * ZF: new treatment of arithmetic (nat & int) may break some old
  5262 proofs;
  5263 
  5264 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5265 rulify -> rule_format, elimify -> elim_format, ...);
  5266 
  5267 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5268 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5269 should have to change intro!! to intro? only); replaced "delrule" by
  5270 "rule del";
  5271 
  5272 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5273 
  5274 * Provers: strengthened force_tac by using new first_best_tac;
  5275 
  5276 * LaTeX document preparation: several changes of isabelle.sty (see
  5277 lib/texinputs);
  5278 
  5279 
  5280 *** Document preparation ***
  5281 
  5282 * formal comments (text blocks etc.) in new-style theories may now
  5283 contain antiquotations of thm/prop/term/typ/text to be presented
  5284 according to latex print mode; concrete syntax is like this:
  5285 @{term[show_types] "f(x) = a + x"};
  5286 
  5287 * isatool mkdir provides easy setup of Isabelle session directories,
  5288 including proper document sources;
  5289 
  5290 * generated LaTeX sources are now deleted after successful run
  5291 (isatool document -c); may retain a copy somewhere else via -D option
  5292 of isatool usedir;
  5293 
  5294 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5295 style files, achieving self-contained LaTeX sources and simplifying
  5296 LaTeX debugging;
  5297 
  5298 * old-style theories now produce (crude) LaTeX output as well;
  5299 
  5300 * browser info session directories are now self-contained (may be put
  5301 on WWW server seperately); improved graphs of nested sessions; removed
  5302 graph for 'all sessions';
  5303 
  5304 * several improvements in isabelle style files; \isabellestyle{it}
  5305 produces fake math mode output; \isamarkupheader is now \section by
  5306 default; see lib/texinputs/isabelle.sty etc.;
  5307 
  5308 
  5309 *** Isar ***
  5310 
  5311 * Isar/Pure: local results and corresponding term bindings are now
  5312 subject to Hindley-Milner polymorphism (similar to ML); this
  5313 accommodates incremental type-inference very nicely;
  5314 
  5315 * Isar/Pure: new derived language element 'obtain' supports
  5316 generalized existence reasoning;
  5317 
  5318 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5319 support accumulation of results, without applying any rules yet;
  5320 useful to collect intermediate results without explicit name
  5321 references, and for use with transitivity rules with more than 2
  5322 premises;
  5323 
  5324 * Isar/Pure: scalable support for case-analysis type proofs: new
  5325 'case' language element refers to local contexts symbolically, as
  5326 produced by certain proof methods; internally, case names are attached
  5327 to theorems as "tags";
  5328 
  5329 * Isar/Pure: theory command 'hide' removes declarations from
  5330 class/type/const name spaces;
  5331 
  5332 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5333 indicate potential overloading;
  5334 
  5335 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5336 
  5337 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5338 "{a,b,c}" instead of {a,b,c};
  5339 
  5340 * Isar/Pure now provides its own version of intro/elim/dest
  5341 attributes; useful for building new logics, but beware of confusion
  5342 with the version in Provers/classical;
  5343 
  5344 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5345 case name 'antecedent';
  5346 
  5347 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5348 to the current context is now done automatically);
  5349 
  5350 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5351 for definining proof methods in ML;
  5352 
  5353 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5354 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5355 most cases, one should have to change intro!! to intro? only);
  5356 replaced "delrule" by "rule del";
  5357 
  5358 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5359 'symmetric' attribute (the latter supercedes [RS sym]);
  5360 
  5361 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5362 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5363 well (including splits);
  5364 
  5365 * Isar/Provers: Simplifier and Classical methods now support all kind
  5366 of modifiers used in the past, including 'cong', 'iff', etc.
  5367 
  5368 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5369 of Simplifier and Classical reasoner);
  5370 
  5371 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5372 now support named cases; major packages (inductive, datatype, primrec,
  5373 recdef) support case names and properly name parameters;
  5374 
  5375 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5376 monotonicity conditions are extracted to be proven at end of
  5377 calculations;
  5378 
  5379 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5380 method anyway;
  5381 
  5382 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5383 split_if split_if_asm; datatype package provides theorems foo.splits =
  5384 foo.split foo.split_asm for each datatype;
  5385 
  5386 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5387 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5388 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5389 use "(cases (simplified))" method in proper proof texts);
  5390 
  5391 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5392 
  5393 * Isar: names of theorems etc. may be natural numbers as well;
  5394 
  5395 * Isar: 'pr' command: optional arguments for goals_limit and
  5396 ProofContext.prems_limit; no longer prints theory contexts, but only
  5397 proof states;
  5398 
  5399 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5400 additional print modes to be specified; e.g. "pr(latex)" will print
  5401 proof state according to the Isabelle LaTeX style;
  5402 
  5403 * Isar: improved support for emulating tactic scripts, including proof
  5404 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5405 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5406 (for HOL datatypes);
  5407 
  5408 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5409 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5410 'proof method scripts' have to be in depth-first order;
  5411 
  5412 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5413 
  5414 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5415 should instead use individual commands for printing items
  5416 (print_commands, print_methods etc.);
  5417 
  5418 * Isar: added 'nothing' --- the empty list of theorems;
  5419 
  5420 
  5421 *** HOL ***
  5422 
  5423 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5424 corresponding virtual machine and a specification of its bytecode
  5425 verifier and a lightweight bytecode verifier, including proofs of
  5426 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5427 Cornelia Pusch (see also the homepage of project Bali at
  5428 http://isabelle.in.tum.de/Bali/);
  5429 
  5430 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5431 Clemens Ballarin;
  5432 
  5433 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5434 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5435 Rasmussen;
  5436 
  5437 * HOL/Lattice: fundamental concepts of lattice theory and order
  5438 structures, including duals, properties of bounds versus algebraic
  5439 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5440 Theorem for complete lattices etc.; may also serve as a demonstration
  5441 for abstract algebraic reasoning using axiomatic type classes, and
  5442 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5443 
  5444 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5445 von Oheimb;
  5446 
  5447 * HOL/IMPP: extension of IMP with local variables and mutually
  5448 recursive procedures, by David von Oheimb;
  5449 
  5450 * HOL/Lambda: converted into new-style theory and document;
  5451 
  5452 * HOL/ex/Multiquote: example of multiple nested quotations and
  5453 anti-quotations -- basically a generalized version of de-Bruijn
  5454 representation; very useful in avoiding lifting of operations;
  5455 
  5456 * HOL/record: added general record equality rule to simpset; fixed
  5457 select-update simplification procedure to handle extended records as
  5458 well; admit "r" as field name;
  5459 
  5460 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5461 other numeric types and also as the identity of groups, rings, etc.;
  5462 
  5463 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5464 Types nat and int belong to this axclass;
  5465 
  5466 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5467    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5468    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5469   two terms #m*u and #n*u are replaced by #(m+n)*u
  5470     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5471   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5472     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5473 
  5474 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5475 powerful prover for predicate logic but knows nothing of clasets; see
  5476 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5477 
  5478 * HOL: new version of "case_tac" subsumes both boolean case split and
  5479 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5480 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5481 
  5482 * HOL: simplification no longer dives into case-expressions: only the
  5483 selector expression is simplified, but not the remaining arms; to
  5484 enable full simplification of case-expressions for datatype t, you may
  5485 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5486 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5487 
  5488 * HOL/recdef: the recursion equations generated by 'recdef' for
  5489 function 'f' are now called f.simps instead of f.rules; if all
  5490 termination conditions are proved automatically, these simplification
  5491 rules are added to the simpset, as in primrec; rules may be named
  5492 individually as well, resulting in a separate list of theorems for
  5493 each equation;
  5494 
  5495 * HOL/While is a new theory that provides a while-combinator. It
  5496 permits the definition of tail-recursive functions without the
  5497 provision of a termination measure. The latter is necessary once the
  5498 invariant proof rule for while is applied.
  5499 
  5500 * HOL: new (overloaded) notation for the set of elements below/above
  5501 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5502 
  5503 * HOL: theorems impI, allI, ballI bound as "strip";
  5504 
  5505 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5506 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5507 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5508 
  5509 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5510 
  5511 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5512 main HOL, but was unused);
  5513 
  5514 * HOL: fewer consts declared as global (e.g. have to refer to
  5515 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5516 
  5517 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5518 in case of overlap with user translations (e.g. judgements over
  5519 tuples); (note that the underlying logical represenation is still
  5520 bogus);
  5521 
  5522 
  5523 *** ZF ***
  5524 
  5525 * ZF: simplification automatically cancels common terms in arithmetic
  5526 expressions over nat and int;
  5527 
  5528 * ZF: new treatment of nat to minimize type-checking: all operators
  5529 coerce their operands to a natural number using the function natify,
  5530 making the algebraic laws unconditional;
  5531 
  5532 * ZF: as above, for int: operators coerce their operands to an integer
  5533 using the function intify;
  5534 
  5535 * ZF: the integer library now contains many of the usual laws for the
  5536 orderings, including $<=, and monotonicity laws for $+ and $*;
  5537 
  5538 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5539 simplification;
  5540 
  5541 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5542 to the simplifier and classical reasoner simultaneously;
  5543 
  5544 
  5545 *** General ***
  5546 
  5547 * Provers: blast_tac now handles actual object-logic rules as
  5548 assumptions; note that auto_tac uses blast_tac internally as well;
  5549 
  5550 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5551 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5552 
  5553 * Provers: delrules now handles destruct rules as well (no longer need
  5554 explicit make_elim);
  5555 
  5556 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5557   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5558 use instead the strong form,
  5559   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5560 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5561 from destruct-rules;
  5562 
  5563 * Provers: Simplifier.easy_setup provides a fast path to basic
  5564 Simplifier setup for new object-logics;
  5565 
  5566 * Pure: AST translation rules no longer require constant head on LHS;
  5567 
  5568 * Pure: improved name spaces: ambiguous output is qualified; support
  5569 for hiding of names;
  5570 
  5571 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5572 XSYMBOL_HOME; no longer need to do manual configuration in most
  5573 situations;
  5574 
  5575 * system: compression of ML heaps images may now be controlled via -c
  5576 option of isabelle and isatool usedir (currently only observed by
  5577 Poly/ML);
  5578 
  5579 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5580 useful for remote X11);
  5581 
  5582 * system: provide TAGS file for Isabelle sources;
  5583 
  5584 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5585 order;
  5586 
  5587 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5588 timing flag supersedes proof_timing and Toplevel.trace;
  5589 
  5590 * ML: new combinators |>> and |>>> for incremental transformations
  5591 with secondary results (e.g. certain theory extensions):
  5592 
  5593 * ML: PureThy.add_defs gets additional argument to indicate potential
  5594 overloading (usually false);
  5595 
  5596 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5597 results;
  5598 
  5599 
  5600 
  5601 New in Isabelle99 (October 1999)
  5602 --------------------------------
  5603 
  5604 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5605 
  5606 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5607 are no longer simplified.  (This allows the simplifier to unfold recursive
  5608 functional programs.)  To restore the old behaviour, declare
  5609 
  5610     Delcongs [if_weak_cong];
  5611 
  5612 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5613 complement;
  5614 
  5615 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5616 
  5617 * HOL/datatype: mutual_induct_tac no longer exists --
  5618   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5619 
  5620 * HOL/typedef: fixed type inference for representing set; type
  5621 arguments now have to occur explicitly on the rhs as type constraints;
  5622 
  5623 * ZF: The con_defs part of an inductive definition may no longer refer
  5624 to constants declared in the same theory;
  5625 
  5626 * HOL, ZF: the function mk_cases, generated by the inductive
  5627 definition package, has lost an argument.  To simplify its result, it
  5628 uses the default simpset instead of a supplied list of theorems.
  5629 
  5630 * HOL/List: the constructors of type list are now Nil and Cons;
  5631 
  5632 * Simplifier: the type of the infix ML functions
  5633         setSSolver addSSolver setSolver addSolver
  5634 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5635 for packaging solvers. A solver is created via
  5636         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5637 where the string argument is only a comment.
  5638 
  5639 
  5640 *** Proof tools ***
  5641 
  5642 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5643 decision procedure for linear arithmetic. Currently it is used for
  5644 types `nat', `int', and `real' in HOL (see below); it can, should and
  5645 will be instantiated for other types and logics as well.
  5646 
  5647 * The simplifier now accepts rewrite rules with flexible heads, eg
  5648      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5649   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5650   matching.
  5651 
  5652 
  5653 *** General ***
  5654 
  5655 * New Isabelle/Isar subsystem provides an alternative to traditional
  5656 tactical theorem proving; together with the ProofGeneral/isar user
  5657 interface it offers an interactive environment for developing human
  5658 readable proof documents (Isar == Intelligible semi-automated
  5659 reasoning); for further information see isatool doc isar-ref,
  5660 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5661 
  5662 * improved and simplified presentation of theories: better HTML markup
  5663 (including colors), graph views in several sizes; isatool usedir now
  5664 provides a proper interface for user theories (via -P option); actual
  5665 document preparation based on (PDF)LaTeX is available as well (for
  5666 new-style theories only); see isatool doc system for more information;
  5667 
  5668 * native support for Proof General, both for classic Isabelle and
  5669 Isabelle/Isar;
  5670 
  5671 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5672 using the graph browser tool;
  5673 
  5674 * Isabelle manuals now also available as PDF;
  5675 
  5676 * theory loader rewritten from scratch (may not be fully
  5677 bug-compatible); old loadpath variable has been replaced by show_path,
  5678 add_path, del_path, reset_path functions; new operations such as
  5679 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5680 isatool doc ref);
  5681 
  5682 * improved isatool install: option -k creates KDE application icon,
  5683 option -p DIR installs standalone binaries;
  5684 
  5685 * added ML_PLATFORM setting (useful for cross-platform installations);
  5686 more robust handling of platform specific ML images for SML/NJ;
  5687 
  5688 * the settings environment is now statically scoped, i.e. it is never
  5689 created again in sub-processes invoked from isabelle, isatool, or
  5690 Isabelle;
  5691 
  5692 * path element specification '~~' refers to '$ISABELLE_HOME';
  5693 
  5694 * in locales, the "assumes" and "defines" parts may be omitted if
  5695 empty;
  5696 
  5697 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5698 long arrows);
  5699 
  5700 * new print_mode "HTML";
  5701 
  5702 * new flag show_tags controls display of tags of theorems (which are
  5703 basically just comments that may be attached by some tools);
  5704 
  5705 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5706 mode and goal output format:
  5707 
  5708 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5709 244c244
  5710 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5711 ---
  5712 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5713 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5714 181c181
  5715 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5716 ---
  5717 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5718 
  5719 * function bind_thms stores lists of theorems (cf. bind_thm);
  5720 
  5721 * new shorthand tactics ftac, eatac, datac, fatac;
  5722 
  5723 * qed (and friends) now accept "" as result name; in that case the
  5724 theorem is not stored, but proper checks and presentation of the
  5725 result still apply;
  5726 
  5727 * theorem database now also indexes constants "Trueprop", "all",
  5728 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5729 
  5730 
  5731 *** HOL ***
  5732 
  5733 ** HOL arithmetic **
  5734 
  5735 * There are now decision procedures for linear arithmetic over nat and
  5736 int:
  5737 
  5738 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5739 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5740 are treated as atomic; subformulae not involving type `nat' or `int'
  5741 are ignored; quantified subformulae are ignored unless they are
  5742 positive universal or negative existential. The tactic has to be
  5743 invoked by hand and can be a little bit slow. In particular, the
  5744 running time is exponential in the number of occurrences of `min' and
  5745 `max', and `-' on `nat'.
  5746 
  5747 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5748 (negated) (in)equalities among the premises and the conclusion into
  5749 account (i.e. no compound formulae) and does not know about `min' and
  5750 `max', and `-' on `nat'. It is fast and is used automatically by the
  5751 simplifier.
  5752 
  5753 NB: At the moment, these decision procedures do not cope with mixed
  5754 nat/int formulae where the two parts interact, such as `m < n ==>
  5755 int(m) < int(n)'.
  5756 
  5757 * HOL/Numeral provides a generic theory of numerals (encoded
  5758 efficiently as bit strings); setup for types nat/int/real is in place;
  5759 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5760 int, existing theories and proof scripts may require a few additional
  5761 type constraints;
  5762 
  5763 * integer division and remainder can now be performed on constant
  5764 arguments;
  5765 
  5766 * many properties of integer multiplication, division and remainder
  5767 are now available;
  5768 
  5769 * An interface to the Stanford Validity Checker (SVC) is available through the
  5770 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5771 are proved automatically.  SVC must be installed separately, and its results
  5772 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5773 invocation of the underlying oracle).  For SVC see
  5774   http://verify.stanford.edu/SVC
  5775 
  5776 * IsaMakefile: the HOL-Real target now builds an actual image;
  5777 
  5778 
  5779 ** HOL misc **
  5780 
  5781 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5782 (in Isabelle/Isar) -- by Gertrud Bauer;
  5783 
  5784 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5785 analysis for assembly languages with subtypes;
  5786 
  5787 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5788 -- avoids syntactic ambiguities and treats state, transition, and
  5789 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5790 changed syntax and (many) tactics;
  5791 
  5792 * HOL/inductive: Now also handles more general introduction rules such
  5793   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5794   theorems are now maintained within the theory (maintained via the
  5795   "mono" attribute);
  5796 
  5797 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5798   (using function types) such as
  5799 
  5800   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5801 
  5802 * HOL/record: record_simproc (part of the default simpset) takes care
  5803 of selectors applied to updated records; record_split_tac is no longer
  5804 part of the default claset; update_defs may now be removed from the
  5805 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5806 
  5807   claset_ref () := claset() addSWrapper record_split_wrapper;
  5808   Delsimprocs [record_simproc]
  5809 
  5810 * HOL/typedef: fixed type inference for representing set; type
  5811 arguments now have to occur explicitly on the rhs as type constraints;
  5812 
  5813 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5814 names rather than an ML expression;
  5815 
  5816 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5817 supplied later.  Program schemes can be defined, such as
  5818     "While B C s = (if B s then While B C (C s) else s)"
  5819 where the well-founded relation can be chosen after B and C have been given.
  5820 
  5821 * HOL/List: the constructors of type list are now Nil and Cons;
  5822 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5823 course, ML tools referring to List.list.op # etc. have to be adapted;
  5824 
  5825 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5826 disabled by default; run isabelle with option -m HOL to get back to
  5827 the original Gordon/HOL-style output;
  5828 
  5829 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5830 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5831 
  5832 * HOL basic syntax simplified (more orthogonal): all variants of
  5833 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5834 Eps operator is provided as well: "SOME x. P[x]";
  5835 
  5836 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5837 
  5838 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5839 thus available for user theories;
  5840 
  5841 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5842 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5843 time;
  5844 
  5845 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5846 several times and then mp;
  5847 
  5848 
  5849 *** LK ***
  5850 
  5851 * the notation <<...>> is now available as a notation for sequences of
  5852 formulas;
  5853 
  5854 * the simplifier is now installed
  5855 
  5856 * the axiom system has been generalized (thanks to Soren Heilmann)
  5857 
  5858 * the classical reasoner now has a default rule database
  5859 
  5860 
  5861 *** ZF ***
  5862 
  5863 * new primrec section allows primitive recursive functions to be given
  5864 directly (as in HOL) over datatypes and the natural numbers;
  5865 
  5866 * new tactics induct_tac and exhaust_tac for induction (or case
  5867 analysis) over datatypes and the natural numbers;
  5868 
  5869 * the datatype declaration of type T now defines the recursor T_rec;
  5870 
  5871 * simplification automatically does freeness reasoning for datatype
  5872 constructors;
  5873 
  5874 * automatic type-inference, with AddTCs command to insert new
  5875 type-checking rules;
  5876 
  5877 * datatype introduction rules are now added as Safe Introduction rules
  5878 to the claset;
  5879 
  5880 * the syntax "if P then x else y" is now available in addition to
  5881 if(P,x,y);
  5882 
  5883 
  5884 *** Internal programming interfaces ***
  5885 
  5886 * tuned simplifier trace output; new flag debug_simp;
  5887 
  5888 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5889 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5890 
  5891 * AxClass.axclass_tac lost the theory argument;
  5892 
  5893 * tuned current_goals_markers semantics: begin / end goal avoids
  5894 printing empty lines;
  5895 
  5896 * removed prs and prs_fn hook, which was broken because it did not
  5897 include \n in its semantics, forcing writeln to add one
  5898 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5899 string -> unit if you really want to output text without newline;
  5900 
  5901 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5902 plain output, interface builders may have to enable 'isabelle_font'
  5903 mode to get Isabelle font glyphs as before;
  5904 
  5905 * refined token_translation interface; INCOMPATIBILITY: output length
  5906 now of type real instead of int;
  5907 
  5908 * theory loader actions may be traced via new ThyInfo.add_hook
  5909 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5910 your own database of information attached to *whole* theories -- as
  5911 opposed to intra-theory data slots offered via TheoryDataFun;
  5912 
  5913 * proper handling of dangling sort hypotheses (at last!);
  5914 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5915 extra sort hypotheses that can be witnessed from the type signature;
  5916 the force_strip_shyps flag is gone, any remaining shyps are simply
  5917 left in the theorem (with a warning issued by strip_shyps_warning);
  5918 
  5919 
  5920 
  5921 New in Isabelle98-1 (October 1998)
  5922 ----------------------------------
  5923 
  5924 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5925 
  5926 * several changes of automated proof tools;
  5927 
  5928 * HOL: major changes to the inductive and datatype packages, including
  5929 some minor incompatibilities of theory syntax;
  5930 
  5931 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5932 called `inj_on';
  5933 
  5934 * HOL: removed duplicate thms in Arith:
  5935   less_imp_add_less  should be replaced by  trans_less_add1
  5936   le_imp_add_le      should be replaced by  trans_le_add1
  5937 
  5938 * HOL: unary minus is now overloaded (new type constraints may be
  5939 required);
  5940 
  5941 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5942 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5943 now taken as an integer constant.
  5944 
  5945 * Pure: ML function 'theory_of' renamed to 'theory';
  5946 
  5947 
  5948 *** Proof tools ***
  5949 
  5950 * Simplifier:
  5951   1. Asm_full_simp_tac is now more aggressive.
  5952      1. It will sometimes reorient premises if that increases their power to
  5953         simplify.
  5954      2. It does no longer proceed strictly from left to right but may also
  5955         rotate premises to achieve further simplification.
  5956      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5957      old Asm_full_simp_tac in that it does not rotate premises.
  5958   2. The simplifier now knows a little bit about nat-arithmetic.
  5959 
  5960 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5961 allows for selected deletion of wrappers, by introduction of names for
  5962 wrapper functionals.  This implies that addbefore, addSbefore,
  5963 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5964 and that adding two tactics with the same name overwrites the first
  5965 one (emitting a warning).
  5966   type wrapper = (int -> tactic) -> (int -> tactic)
  5967   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5968   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5969   delWrapper, delSWrapper: claset *  string            -> claset
  5970   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5971 
  5972 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5973 semantics; addbefore now affects only the unsafe part of step_tac
  5974 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5975 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5976 by Force_tac;
  5977 
  5978 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5979 compWrapper; added safe wrapper (and access functions for it);
  5980 
  5981 * HOL/split_all_tac is now much faster and fails if there is nothing
  5982 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5983 and the names of the automatically generated variables have changed.
  5984 split_all_tac has moved within claset() from unsafe wrappers to safe
  5985 wrappers, which means that !!-bound variables are split much more
  5986 aggressively, and safe_tac and clarify_tac now split such variables.
  5987 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5988 Note: the same holds for record_split_tac, which does the job of
  5989 split_all_tac for record fields.
  5990 
  5991 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5992 permanently to the default simpset using Addsplits just like
  5993 Addsimps. They can be removed via Delsplits just like
  5994 Delsimps. Lower-case versions are also available.
  5995 
  5996 * HOL/Simplifier: The rule split_if is now part of the default
  5997 simpset. This means that the simplifier will eliminate all occurrences
  5998 of if-then-else in the conclusion of a goal. To prevent this, you can
  5999 either remove split_if completely from the default simpset by
  6000 `Delsplits [split_if]' or remove it in a specific call of the
  6001 simplifier using `... delsplits [split_if]'.  You can also add/delete
  6002 other case splitting rules to/from the default simpset: every datatype
  6003 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  6004 t is the name of the datatype).
  6005 
  6006 * Classical reasoner / Simplifier combination: new force_tac (and
  6007 derivatives Force_tac, force) combines rewriting and classical
  6008 reasoning (and whatever other tools) similarly to auto_tac, but is
  6009 aimed to solve the given subgoal completely.
  6010 
  6011 
  6012 *** General ***
  6013 
  6014 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  6015 and `goalw': the theory is no longer needed as an explicit argument -
  6016 the current theory context is used; assumptions are no longer returned
  6017 at the ML-level unless one of them starts with ==> or !!; it is
  6018 recommended to convert to these new commands using isatool fixgoal
  6019 (backup your sources first!);
  6020 
  6021 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  6022 the current theory context, and 'theory' to lookup stored theories;
  6023 
  6024 * new theory section 'locale' for declaring constants, assumptions and
  6025 definitions that have local scope;
  6026 
  6027 * new theory section 'nonterminals' for purely syntactic types;
  6028 
  6029 * new theory section 'setup' for generic ML setup functions
  6030 (e.g. package initialization);
  6031 
  6032 * the distribution now includes Isabelle icons: see
  6033 lib/logo/isabelle-{small,tiny}.xpm;
  6034 
  6035 * isatool install - install binaries with absolute references to
  6036 ISABELLE_HOME/bin;
  6037 
  6038 * isatool logo -- create instances of the Isabelle logo (as EPS);
  6039 
  6040 * print mode 'emacs' reserved for Isamode;
  6041 
  6042 * support multiple print (ast) translations per constant name;
  6043 
  6044 * theorems involving oracles are now printed with a suffixed [!];
  6045 
  6046 
  6047 *** HOL ***
  6048 
  6049 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  6050 
  6051 * HOL/inductive package reorganized and improved: now supports mutual
  6052 definitions such as
  6053 
  6054   inductive EVEN ODD
  6055     intrs
  6056       null "0 : EVEN"
  6057       oddI "n : EVEN ==> Suc n : ODD"
  6058       evenI "n : ODD ==> Suc n : EVEN"
  6059 
  6060 new theorem list "elims" contains an elimination rule for each of the
  6061 recursive sets; inductive definitions now handle disjunctive premises
  6062 correctly (also ZF);
  6063 
  6064 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  6065 "mutual_induct" no longer exists - the induction rule is always
  6066 contained in "induct";
  6067 
  6068 
  6069 * HOL/datatype package re-implemented and greatly improved: now
  6070 supports mutually recursive datatypes such as
  6071 
  6072   datatype
  6073     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  6074             | SUM ('a aexp) ('a aexp)
  6075             | DIFF ('a aexp) ('a aexp)
  6076             | NUM 'a
  6077   and
  6078     'a bexp = LESS ('a aexp) ('a aexp)
  6079             | AND ('a bexp) ('a bexp)
  6080             | OR ('a bexp) ('a bexp)
  6081 
  6082 as well as indirectly recursive datatypes such as
  6083 
  6084   datatype
  6085     ('a, 'b) term = Var 'a
  6086                   | App 'b ((('a, 'b) term) list)
  6087 
  6088 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  6089 induction on mutually / indirectly recursive datatypes.
  6090 
  6091 Primrec equations are now stored in theory and can be accessed via
  6092 <function_name>.simps.
  6093 
  6094 INCOMPATIBILITIES:
  6095 
  6096   - Theories using datatypes must now have theory Datatype as an
  6097     ancestor.
  6098   - The specific <typename>.induct_tac no longer exists - use the
  6099     generic induct_tac instead.
  6100   - natE has been renamed to nat.exhaust - use exhaust_tac
  6101     instead of res_inst_tac ... natE. Note that the variable
  6102     names in nat.exhaust differ from the names in natE, this
  6103     may cause some "fragile" proofs to fail.
  6104   - The theorems split_<typename>_case and split_<typename>_case_asm
  6105     have been renamed to <typename>.split and <typename>.split_asm.
  6106   - Since default sorts of type variables are now handled correctly,
  6107     some datatype definitions may have to be annotated with explicit
  6108     sort constraints.
  6109   - Primrec definitions no longer require function name and type
  6110     of recursive argument.
  6111 
  6112 Consider using isatool fixdatatype to adapt your theories and proof
  6113 scripts to the new package (backup your sources first!).
  6114 
  6115 
  6116 * HOL/record package: considerably improved implementation; now
  6117 includes concrete syntax for record types, terms, updates; theorems
  6118 for surjective pairing and splitting !!-bound record variables; proof
  6119 support is as follows:
  6120 
  6121   1) standard conversions (selectors or updates applied to record
  6122 constructor terms) are part of the standard simpset;
  6123 
  6124   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  6125 made part of standard simpset and claset via addIffs;
  6126 
  6127   3) a tactic for record field splitting (record_split_tac) is part of
  6128 the standard claset (addSWrapper);
  6129 
  6130 To get a better idea about these rules you may retrieve them via
  6131 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  6132 the name of your record type.
  6133 
  6134 The split tactic 3) conceptually simplifies by the following rule:
  6135 
  6136   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  6137 
  6138 Thus any record variable that is bound by meta-all will automatically
  6139 blow up into some record constructor term, consequently the
  6140 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  6141 solve record problems automatically.
  6142 
  6143 
  6144 * reorganized the main HOL image: HOL/Integ and String loaded by
  6145 default; theory Main includes everything;
  6146 
  6147 * automatic simplification of integer sums and comparisons, using cancellation;
  6148 
  6149 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  6150 
  6151 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  6152 
  6153 * many new identities for unions, intersections, set difference, etc.;
  6154 
  6155 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  6156 called split_if, split_split, split_sum_case and split_nat_case (to go
  6157 with add/delsplits);
  6158 
  6159 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  6160 (?x::unit) = (); this is made part of the default simpset, which COULD
  6161 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  6162 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  6163 unit_abs_eta_conv is added in order to counter the effect of
  6164 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  6165 %u.f();
  6166 
  6167 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  6168 makes more sense);
  6169 
  6170 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6171   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6172   disjointness reasoning but breaking a few old proofs.
  6173 
  6174 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  6175 to 'converse' from 'inverse' (for compatibility with ZF and some
  6176 literature);
  6177 
  6178 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  6179 the well-founded relation;
  6180 
  6181 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  6182     Compl A.  The "Compl" syntax remains available as input syntax for this
  6183     release ONLY.
  6184 
  6185 * HOL/Update: new theory of function updates:
  6186     f(a:=b) == %x. if x=a then b else f x
  6187 may also be iterated as in f(a:=b,c:=d,...);
  6188 
  6189 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  6190 
  6191 * HOL/List:
  6192   - new function list_update written xs[i:=v] that updates the i-th
  6193     list position. May also be iterated as in xs[i:=a,j:=b,...].
  6194   - new function `upt' written [i..j(] which generates the list
  6195     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  6196     bound write [i..j], which is a shorthand for [i..j+1(].
  6197   - new lexicographic orderings and corresponding wellfoundedness theorems.
  6198 
  6199 * HOL/Arith:
  6200   - removed 'pred' (predecessor) function;
  6201   - generalized some theorems about n-1;
  6202   - many new laws about "div" and "mod";
  6203   - new laws about greatest common divisors (see theory ex/Primes);
  6204 
  6205 * HOL/Relation: renamed the relational operator r^-1 "converse"
  6206 instead of "inverse";
  6207 
  6208 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  6209   of the multiset ordering;
  6210 
  6211 * directory HOL/Real: a construction of the reals using Dedekind cuts
  6212   (not included by default);
  6213 
  6214 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  6215 
  6216 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  6217   programs, i.e. different program variables may have different types.
  6218 
  6219 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6220   [previously, this check worked only if the rewrite rule was unconditional]
  6221   Now rew can involve either definitions or equalities (either == or =).
  6222 
  6223 
  6224 *** ZF ***
  6225 
  6226 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  6227   only the theorems proved on ZF.ML;
  6228 
  6229 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6230   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6231   disjointness reasoning but breaking a few old proofs.
  6232 
  6233 * ZF/Update: new theory of function updates
  6234     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  6235   may also be iterated as in f(a:=b,c:=d,...);
  6236 
  6237 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6238 
  6239 * calling (stac rew i) now fails if "rew" has no effect on the goal