NEWS
author krauss
Mon Mar 01 17:05:57 2010 +0100 (2010-03-01)
changeset 35419 d78659d1723e
parent 35401 bfcbab8592ba
child 35413 4c7cba1f7ce9
permissions -rw-r--r--
more recdef (and old primrec) hunting
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Authentic syntax for *all* term constants: provides simple and
    10 robust correspondence between formal entities and concrete syntax.
    11 Substantial INCOMPATIBILITY concerning low-level syntax translations
    12 (translation rules and translation functions in ML).  Some hints on
    13 upgrading:
    14 
    15   - Many existing uses of 'syntax' and 'translations' can be replaced
    16     by more modern 'notation' and 'abbreviation', which are
    17     independent of this issue.
    18 
    19   - 'translations' require markup within the AST; the term syntax
    20     provides the following special forms:
    21 
    22       CONST c   -- produces syntax version of constant c from context
    23       XCONST c  -- literally c, checked as constant from context
    24       c         -- literally c, if declared by 'syntax'
    25 
    26     Plain identifiers are treated as AST variables -- occasionally the
    27     system indicates accidental variables via the error "rhs contains
    28     extra variables".
    29 
    30   - 'parse_translation' etc. in ML may use the following
    31     antiquotations:
    32 
    33       @{const_syntax c}   -- ML version of "CONST c" above
    34       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
    35 
    36 Note that old non-authentic syntax was based on unqualified base
    37 names, so all of the above would coincide.  Recall that 'print_syntax'
    38 and ML_command "set Syntax.trace_ast" help to diagnose syntax
    39 problems.
    40 
    41 * Type constructors admit general mixfix syntax, not just infix.
    42 
    43 
    44 *** Pure ***
    45 
    46 * Code generator: details of internal data cache have no impact on
    47 the user space functionality any longer.
    48 
    49 * Discontinued unnamed infix syntax (legacy feature for many years) --
    50 need to specify constant name and syntax separately.  Internal ML
    51 datatype constructors have been renamed from InfixName to Infix etc.
    52 Minor INCOMPATIBILITY.
    53 
    54 
    55 *** HOL ***
    56 
    57 * Theory "Rational" renamed to "Rat", for consistency with "Nat", "Int" etc.
    58 INCOMPATIBILITY.
    59 
    60 * New set of rules "ac_simps" provides combined assoc / commute rewrites
    61 for all interpretations of the appropriate generic locales.
    62 
    63 * Renamed theory "OrderedGroup" to "Groups" and split theory "Ring_and_Field"
    64 into theories "Rings" and "Fields";  for more appropriate and more
    65 consistent names suitable for name prefixes within the HOL theories.
    66 INCOMPATIBILITY.
    67 
    68 * Some generic constants have been put to appropriate theories:
    69 
    70     less_eq, less: Orderings
    71     zero, one, plus, minus, uminus, times, abs, sgn: Groups
    72     inverse, divide: Rings
    73 
    74 INCOMPATIBILITY.
    75 
    76 * Class division ring also requires proof of fact divide_inverse.  However instantiation
    77 of parameter divide has also been required previously.  INCOMPATIBILITY.
    78 
    79 * More consistent naming of type classes involving orderings (and lattices):
    80 
    81     lower_semilattice                   ~> semilattice_inf
    82     upper_semilattice                   ~> semilattice_sup
    83 
    84     dense_linear_order                  ~> dense_linorder
    85 
    86     pordered_ab_group_add               ~> ordered_ab_group_add
    87     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
    88     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
    89     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
    90     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
    91     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
    92     pordered_cancel_semiring            ~> ordered_cancel_semiring
    93     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
    94     pordered_comm_ring                  ~> ordered_comm_ring
    95     pordered_comm_semiring              ~> ordered_comm_semiring
    96     pordered_ring                       ~> ordered_ring
    97     pordered_ring_abs                   ~> ordered_ring_abs
    98     pordered_semiring                   ~> ordered_semiring
    99 
   100     ordered_ab_group_add                ~> linordered_ab_group_add
   101     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   102     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   103     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   104     ordered_field                       ~> linordered_field
   105     ordered_field_no_lb                 ~> linordered_field_no_lb
   106     ordered_field_no_ub                 ~> linordered_field_no_ub
   107     ordered_field_dense_linear_order    ~> dense_linordered_field
   108     ordered_idom                        ~> linordered_idom
   109     ordered_ring                        ~> linordered_ring
   110     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   111     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   112     ordered_ring_strict                 ~> linordered_ring_strict
   113     ordered_semidom                     ~> linordered_semidom
   114     ordered_semiring                    ~> linordered_semiring
   115     ordered_semiring_1                  ~> linordered_semiring_1
   116     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   117     ordered_semiring_strict             ~> linordered_semiring_strict
   118 
   119   The following slightly odd type classes have been moved to
   120   a separate theory Library/Lattice_Algebras.thy:
   121 
   122     lordered_ab_group_add               ~> lattice_ab_group_add
   123     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   124     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   125     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   126     lordered_ring                       ~> lattice_ring
   127 
   128 INCOMPATIBILITY.
   129 
   130 * HOLogic.strip_psplit: types are returned in syntactic order, similar
   131 to other strip and tuple operations.  INCOMPATIBILITY.
   132 
   133 * Various old-style primrec specifications in the HOL theories have been
   134 replaced by new-style primrec, especially in theory List.  The corresponding
   135 constants now have authentic syntax.  INCOMPATIBILITY.
   136 
   137 * Reorganized theory Multiset: swapped notation of pointwise and multiset order:
   138   * pointwise ordering is instance of class order with standard syntax <= and <;
   139   * multiset ordering has syntax <=# and <#; partial order properties are provided
   140       by means of interpretation with prefix multiset_order.
   141 Less duplication, less historical organization of sections,
   142 conversion from associations lists to multisets, rudimentary code generation.
   143 Use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union, if needed.
   144 INCOMPATIBILITY.
   145 
   146 * Reorganized theory Sum_Type; Inl and Inr now have authentic syntax.
   147 INCOMPATIBILITY.
   148 
   149 * Code generation: ML and OCaml code is decorated with signatures.
   150 
   151 * Theory Complete_Lattice: lemmas top_def and bot_def have been
   152 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   153 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   154 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   155 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   156 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   157 
   158 * Theory Finite_Set and List: some lemmas have been generalized from
   159 sets to lattices:
   160 
   161   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   162   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   163   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   164   union_Union_fold_union        ~> sup_Sup_fold_sup
   165   Inter_fold_inter              ~> Inf_fold_inf
   166   Union_fold_union              ~> Sup_fold_sup
   167   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   168   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   169   INTER_fold_inter              ~> INFI_fold_inf
   170   UNION_fold_union              ~> SUPR_fold_sup
   171 
   172 * Theory List: added transpose.
   173 
   174 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   175 clash with new theory Quotient in Main HOL.
   176 
   177 
   178 *** ML ***
   179 
   180 * Antiquotations for basic formal entities:
   181 
   182     @{class NAME}         -- type class
   183     @{class_syntax NAME}  -- syntax representation of the above
   184 
   185     @{type_name NAME}     -- logical type
   186     @{type_abbrev NAME}   -- type abbreviation
   187     @{nonterminal NAME}   -- type of concrete syntactic category
   188     @{type_syntax NAME}   -- syntax representation of any of the above
   189 
   190     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
   191     @{const_abbrev NAME}  -- abbreviated constant
   192     @{const_syntax NAME}  -- syntax representation of any of the above
   193 
   194 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
   195 syntax constant (cf. 'syntax' command).
   196 
   197 * Renamed old-style Drule.standard to Drule.export_without_context, to
   198 emphasize that this is in no way a standard operation.
   199 INCOMPATIBILITY.
   200 
   201 * Curried take and drop in library.ML; negative length is interpreted
   202 as infinity (as in chop).  INCOMPATIBILITY.
   203 
   204 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
   205 usual for resolution.  Rare INCOMPATIBILITY.
   206 
   207 * Discontinued old TheoryDataFun with its copy/init operation -- data
   208 needs to be pure.  Functor Theory_Data_PP retains the traditional
   209 Pretty.pp argument to merge, which is absent in the standard
   210 Theory_Data version.
   211 
   212 
   213 *** System ***
   214 
   215 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
   216 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
   217 proof terms are enabled unconditionally in the new HOL-Proofs image.
   218 
   219 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
   220 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
   221 respectively.
   222 
   223 
   224 
   225 New in Isabelle2009-1 (December 2009)
   226 -------------------------------------
   227 
   228 *** General ***
   229 
   230 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
   231 one backslash should be used, even in ML sources.
   232 
   233 
   234 *** Pure ***
   235 
   236 * Locale interpretation propagates mixins along the locale hierarchy.
   237 The currently only available mixins are the equations used to map
   238 local definitions to terms of the target domain of an interpretation.
   239 
   240 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
   241 loc" to print all interpretations of locale "loc" in the theory.
   242 Interpretations in proofs are not shown.
   243 
   244 * Thoroughly revised locales tutorial.  New section on conditional
   245 interpretation.
   246 
   247 * On instantiation of classes, remaining undefined class parameters
   248 are formally declared.  INCOMPATIBILITY.
   249 
   250 
   251 *** Document preparation ***
   252 
   253 * New generalized style concept for printing terms: @{foo (style) ...}
   254 instead of @{foo_style style ...}  (old form is still retained for
   255 backward compatibility).  Styles can be also applied for
   256 antiquotations prop, term_type and typeof.
   257 
   258 
   259 *** HOL ***
   260 
   261 * New proof method "smt" for a combination of first-order logic with
   262 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   263 fixed-size bitvectors; there is also basic support for higher-order
   264 features (esp. lambda abstractions).  It is an incomplete decision
   265 procedure based on external SMT solvers using the oracle mechanism;
   266 for the SMT solver Z3, this method is proof-producing.  Certificates
   267 are provided to avoid calling the external solvers solely for
   268 re-checking proofs.  Due to a remote SMT service there is no need for
   269 installing SMT solvers locally.  See src/HOL/SMT.
   270 
   271 * New commands to load and prove verification conditions generated by
   272 the Boogie program verifier or derived systems (e.g. the Verifying C
   273 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   274 
   275 * New counterexample generator tool 'nitpick' based on the Kodkod
   276 relational model finder.  See src/HOL/Tools/Nitpick and
   277 src/HOL/Nitpick_Examples.
   278 
   279 * New commands 'code_pred' and 'values' to invoke the predicate
   280 compiler and to enumerate values of inductive predicates.
   281 
   282 * A tabled implementation of the reflexive transitive closure.
   283 
   284 * New implementation of quickcheck uses generic code generator;
   285 default generators are provided for all suitable HOL types, records
   286 and datatypes.  Old quickcheck can be re-activated importing theory
   287 Library/SML_Quickcheck.
   288 
   289 * New testing tool Mirabelle for automated proof tools.  Applies
   290 several tools and tactics like sledgehammer, metis, or quickcheck, to
   291 every proof step in a theory.  To be used in batch mode via the
   292 "mirabelle" utility.
   293 
   294 * New proof method "sos" (sum of squares) for nonlinear real
   295 arithmetic (originally due to John Harison). It requires theory
   296 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   297 works well in practice on quantifier-free real arithmetic with +, -,
   298 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   299 inequalities between polynomials.  It makes use of external
   300 semidefinite programming solvers.  Method "sos" generates a
   301 certificate that can be pasted into the proof thus avoiding the need
   302 to call an external tool every time the proof is checked.  See
   303 src/HOL/Library/Sum_Of_Squares.
   304 
   305 * New method "linarith" invokes existing linear arithmetic decision
   306 procedure only.
   307 
   308 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   309 
   310 * New Sledgehammer option "Full Types" in Proof General settings menu.
   311 Causes full type information to be output to the ATPs.  This slows
   312 ATPs down considerably but eliminates a source of unsound "proofs"
   313 that fail later.
   314 
   315 * New method "metisFT": A version of metis that uses full type
   316 information in order to avoid failures of proof reconstruction.
   317 
   318 * New evaluator "approximate" approximates an real valued term using
   319 the same method as the approximation method.
   320 
   321 * Method "approximate" now supports arithmetic expressions as
   322 boundaries of intervals and implements interval splitting and Taylor
   323 series expansion.
   324 
   325 * ML antiquotation @{code_datatype} inserts definition of a datatype
   326 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   327 
   328 * New theory SupInf of the supremum and infimum operators for sets of
   329 reals.
   330 
   331 * New theory Probability, which contains a development of measure
   332 theory, eventually leading to Lebesgue integration and probability.
   333 
   334 * Extended Multivariate Analysis to include derivation and Brouwer's
   335 fixpoint theorem.
   336 
   337 * Reorganization of number theory, INCOMPATIBILITY:
   338   - new number theory development for nat and int, in theories Divides
   339     and GCD as well as in new session Number_Theory
   340   - some constants and facts now suffixed with _nat and _int
   341     accordingly
   342   - former session NumberTheory now named Old_Number_Theory, including
   343     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   344   - moved theory Pocklington from src/HOL/Library to
   345     src/HOL/Old_Number_Theory
   346 
   347 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   348 lcm of finite and infinite sets. It is shown that they form a complete
   349 lattice.
   350 
   351 * Class semiring_div requires superclass no_zero_divisors and proof of
   352 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   353 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   354 generalized to class semiring_div, subsuming former theorems
   355 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   356 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   357 INCOMPATIBILITY.
   358 
   359 * Refinements to lattice classes and sets:
   360   - less default intro/elim rules in locale variant, more default
   361     intro/elim rules in class variant: more uniformity
   362   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   363     le_inf_iff
   364   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   365     sup_aci)
   366   - renamed ACI to inf_sup_aci
   367   - new class "boolean_algebra"
   368   - class "complete_lattice" moved to separate theory
   369     "Complete_Lattice"; corresponding constants (and abbreviations)
   370     renamed and with authentic syntax:
   371     Set.Inf ~>    Complete_Lattice.Inf
   372     Set.Sup ~>    Complete_Lattice.Sup
   373     Set.INFI ~>   Complete_Lattice.INFI
   374     Set.SUPR ~>   Complete_Lattice.SUPR
   375     Set.Inter ~>  Complete_Lattice.Inter
   376     Set.Union ~>  Complete_Lattice.Union
   377     Set.INTER ~>  Complete_Lattice.INTER
   378     Set.UNION ~>  Complete_Lattice.UNION
   379   - authentic syntax for
   380     Set.Pow
   381     Set.image
   382   - mere abbreviations:
   383     Set.empty               (for bot)
   384     Set.UNIV                (for top)
   385     Set.inter               (for inf, formerly Set.Int)
   386     Set.union               (for sup, formerly Set.Un)
   387     Complete_Lattice.Inter  (for Inf)
   388     Complete_Lattice.Union  (for Sup)
   389     Complete_Lattice.INTER  (for INFI)
   390     Complete_Lattice.UNION  (for SUPR)
   391   - object-logic definitions as far as appropriate
   392 
   393 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   394 Un_subset_iff are explicitly deleted as default simp rules; then also
   395 their lattice counterparts le_inf_iff and le_sup_iff have to be
   396 deleted to achieve the desired effect.
   397 
   398 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   399 rules by default any longer; the same applies to min_max.inf_absorb1
   400 etc.  INCOMPATIBILITY.
   401 
   402 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   403 pred_set_conv by default.  INCOMPATIBILITY.
   404 
   405 * Power operations on relations and functions are now one dedicated
   406 constant "compow" with infix syntax "^^".  Power operation on
   407 multiplicative monoids retains syntax "^" and is now defined generic
   408 in class power.  INCOMPATIBILITY.
   409 
   410 * Relation composition "R O S" now has a more standard argument order:
   411 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   412 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   413 break, since the O_assoc rule was not rewritten like this.  Fix using
   414 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   415 
   416 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   417 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   418 INCOMPATIBILITY.
   419 
   420 * Most rules produced by inductive and datatype package have mandatory
   421 prefixes.  INCOMPATIBILITY.
   422 
   423 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   424 the attribute of the same name.  Each of the theorems in the list
   425 DERIV_intros assumes composition with an additional function and
   426 matches a variable to the derivative, which has to be solved by the
   427 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   428 of most elementary terms.  Former Maclauren.DERIV_tac and
   429 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   430 INCOMPATIBILITY.
   431 
   432 * Code generator attributes follow the usual underscore convention:
   433     code_unfold     replaces    code unfold
   434     code_post       replaces    code post
   435     etc.
   436   INCOMPATIBILITY.
   437 
   438 * Renamed methods:
   439     sizechange -> size_change
   440     induct_scheme -> induction_schema
   441   INCOMPATIBILITY.
   442 
   443 * Discontinued abbreviation "arbitrary" of constant "undefined".
   444 INCOMPATIBILITY, use "undefined" directly.
   445 
   446 * Renamed theorems:
   447     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   448     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   449     Suc_plus1 -> Suc_eq_plus1
   450     *anti_sym -> *antisym*
   451     vector_less_eq_def -> vector_le_def
   452   INCOMPATIBILITY.
   453 
   454 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   455 INCOMPATIBILITY.
   456 
   457 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   458 INCOMPATIBILITY.
   459 
   460 
   461 *** HOLCF ***
   462 
   463 * Theory Representable defines a class "rep" of domains that are
   464 representable (via an ep-pair) in the universal domain type "udom".
   465 Instances are provided for all type constructors defined in HOLCF.
   466 
   467 * The 'new_domain' command is a purely definitional version of the
   468 domain package, for representable domains.  Syntax is identical to the
   469 old domain package.  The 'new_domain' package also supports indirect
   470 recursion using previously-defined type constructors.  See
   471 src/HOLCF/ex/New_Domain.thy for examples.
   472 
   473 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   474 on the left-hand side of an equation, and then performs
   475 simplification.  Rewriting is done using rules declared with the
   476 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   477 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   478 
   479 * The pattern-match compiler in 'fixrec' can now handle constructors
   480 with HOL function types.  Pattern-match combinators for the Pair
   481 constructor are pre-configured.
   482 
   483 * The 'fixrec' package now produces better fixed-point induction rules
   484 for mutually-recursive definitions:  Induction rules have conclusions
   485 of the form "P foo bar" instead of "P <foo, bar>".
   486 
   487 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   488 been renamed to "below".  The name "below" now replaces "less" in many
   489 theorem names.  (Legacy theorem names using "less" are still supported
   490 as well.)
   491 
   492 * The 'fixrec' package now supports "bottom patterns".  Bottom
   493 patterns can be used to generate strictness rules, or to make
   494 functions more strict (much like the bang-patterns supported by the
   495 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   496 examples.
   497 
   498 
   499 *** ML ***
   500 
   501 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   502 errors and run-time exceptions, including detailed source positions.
   503 
   504 * Structure Name_Space (formerly NameSpace) now manages uniquely
   505 identified entries, with some additional information such as source
   506 position, logical grouping etc.
   507 
   508 * Theory and context data is now introduced by the simplified and
   509 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   510 to be pure, but the old TheoryDataFun for mutable data (with explicit
   511 copy operation) is still available for some time.
   512 
   513 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   514 provides a high-level programming interface to synchronized state
   515 variables with atomic update.  This works via pure function
   516 application within a critical section -- its runtime should be as
   517 short as possible; beware of deadlocks if critical code is nested,
   518 either directly or indirectly via other synchronized variables!
   519 
   520 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   521 wraps raw ML references, explicitly indicating their non-thread-safe
   522 behaviour.  The Isar toplevel keeps this structure open, to
   523 accommodate Proof General as well as quick and dirty interactive
   524 experiments with references.
   525 
   526 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   527 parallel tactical reasoning.
   528 
   529 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   530 are similar to SUBPROOF, but are slightly more flexible: only the
   531 specified parts of the subgoal are imported into the context, and the
   532 body tactic may introduce new subgoals and schematic variables.
   533 
   534 * Old tactical METAHYPS, which does not observe the proof context, has
   535 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   536 or Subgoal.FOCUS etc.
   537 
   538 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   539 functors have their own ML name space there is no point to mark them
   540 separately.)  Minor INCOMPATIBILITY.
   541 
   542 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   543 
   544 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   545 INCOMPATIBILITY.
   546 
   547 * Operations of structure Skip_Proof no longer require quick_and_dirty
   548 mode, which avoids critical setmp.
   549 
   550 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   551 combinators for "args".  INCOMPATIBILITY, need to use simplified
   552 Attrib/Method.setup introduced in Isabelle2009.
   553 
   554 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   555 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   556 last resort.  INCOMPATIBILITY.
   557 
   558 * Display.pretty_thm now requires a proper context (cf. former
   559 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   560 or even Display.pretty_thm_without_context as last resort.
   561 INCOMPATIBILITY.
   562 
   563 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   564 Syntax.pretty_typ/term directly, preferably with proper context
   565 instead of global theory.
   566 
   567 
   568 *** System ***
   569 
   570 * Further fine tuning of parallel proof checking, scales up to 8 cores
   571 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   572 usedir option -q.
   573 
   574 * Support for additional "Isabelle components" via etc/components, see
   575 also the system manual.
   576 
   577 * The isabelle makeall tool now operates on all components with
   578 IsaMakefile, not just hardwired "logics".
   579 
   580 * Removed "compress" option from isabelle-process and isabelle usedir;
   581 this is always enabled.
   582 
   583 * Discontinued support for Poly/ML 4.x versions.
   584 
   585 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   586 on a given logic image.  This requires the lighttpd webserver and is
   587 currently supported on Linux only.
   588 
   589 
   590 
   591 New in Isabelle2009 (April 2009)
   592 --------------------------------
   593 
   594 *** General ***
   595 
   596 * Simplified main Isabelle executables, with less surprises on
   597 case-insensitive file-systems (such as Mac OS).
   598 
   599   - The main Isabelle tool wrapper is now called "isabelle" instead of
   600     "isatool."
   601 
   602   - The former "isabelle" alias for "isabelle-process" has been
   603     removed (should rarely occur to regular users).
   604 
   605   - The former "isabelle-interface" and its alias "Isabelle" have been
   606     removed (interfaces are now regular Isabelle tools).
   607 
   608 Within scripts and make files, the Isabelle environment variables
   609 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   610 respectively.  (The latter are still available as legacy feature.)
   611 
   612 The old isabelle-interface wrapper could react in confusing ways if
   613 the interface was uninstalled or changed otherwise.  Individual
   614 interface tool configuration is now more explicit, see also the
   615 Isabelle system manual.  In particular, Proof General is now available
   616 via "isabelle emacs".
   617 
   618 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   619 purge installed copies of Isabelle executables and re-run "isabelle
   620 install -p ...", or use symlinks.
   621 
   622 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   623 old ~/isabelle, which was slightly non-standard and apt to cause
   624 surprises on case-insensitive file-systems (such as Mac OS).
   625 
   626 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   627 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   628 care is required when using older releases of Isabelle.  Note that
   629 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   630 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   631 
   632 * Proofs of fully specified statements are run in parallel on
   633 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   634 a regular 4-core machine, if the initial heap space is made reasonably
   635 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   636 
   637 * The main reference manuals ("isar-ref", "implementation", and
   638 "system") have been updated and extended.  Formally checked references
   639 as hyperlinks are now available uniformly.
   640 
   641 
   642 *** Pure ***
   643 
   644 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   645 respects.  The most important changes are listed below.  See the
   646 Tutorial on Locales ("locales" manual) for details.
   647 
   648 - In locale expressions, instantiation replaces renaming.  Parameters
   649 must be declared in a for clause.  To aid compatibility with previous
   650 parameter inheritance, in locale declarations, parameters that are not
   651 'touched' (instantiation position "_" or omitted) are implicitly added
   652 with their syntax at the beginning of the for clause.
   653 
   654 - Syntax from abbreviations and definitions in locales is available in
   655 locale expressions and context elements.  The latter is particularly
   656 useful in locale declarations.
   657 
   658 - More flexible mechanisms to qualify names generated by locale
   659 expressions.  Qualifiers (prefixes) may be specified in locale
   660 expressions, and can be marked as mandatory (syntax: "name!:") or
   661 optional (syntax "name?:").  The default depends for plain "name:"
   662 depends on the situation where a locale expression is used: in
   663 commands 'locale' and 'sublocale' prefixes are optional, in
   664 'interpretation' and 'interpret' prefixes are mandatory.  The old
   665 implicit qualifiers derived from the parameter names of a locale are
   666 no longer generated.
   667 
   668 - Command "sublocale l < e" replaces "interpretation l < e".  The
   669 instantiation clause in "interpretation" and "interpret" (square
   670 brackets) is no longer available.  Use locale expressions.
   671 
   672 - When converting proof scripts, mandatory qualifiers in
   673 'interpretation' and 'interpret' should be retained by default, even
   674 if this is an INCOMPATIBILITY compared to former behavior.  In the
   675 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   676 in locale expressions range over a single locale instance only.
   677 
   678 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   679 In existing theorem specifications replace the includes element by the
   680 respective context elements of the included locale, omitting those
   681 that are already present in the theorem specification.  Multiple
   682 assume elements of a locale should be replaced by a single one
   683 involving the locale predicate.  In the proof body, declarations (most
   684 notably theorems) may be regained by interpreting the respective
   685 locales in the proof context as required (command "interpret").
   686 
   687 If using "includes" in replacement of a target solely because the
   688 parameter types in the theorem are not as general as in the target,
   689 consider declaring a new locale with additional type constraints on
   690 the parameters (context element "constrains").
   691 
   692 - Discontinued "locale (open)".  INCOMPATIBILITY.
   693 
   694 - Locale interpretation commands no longer attempt to simplify goal.
   695 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   696 methods intro_locales and unfold_locales to clarify.
   697 
   698 - Locale interpretation commands no longer accept interpretation
   699 attributes.  INCOMPATIBILITY.
   700 
   701 * Class declaration: so-called "base sort" must not be given in import
   702 list any longer, but is inferred from the specification.  Particularly
   703 in HOL, write
   704 
   705     class foo = ...
   706 
   707 instead of
   708 
   709     class foo = type + ...
   710 
   711 * Class target: global versions of theorems stemming do not carry a
   712 parameter prefix any longer.  INCOMPATIBILITY.
   713 
   714 * Class 'instance' command no longer accepts attached definitions.
   715 INCOMPATIBILITY, use proper 'instantiation' target instead.
   716 
   717 * Recovered hiding of consts, which was accidentally broken in
   718 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   719 makes c inaccessible; consider using ``hide (open) const c'' instead.
   720 
   721 * Slightly more coherent Pure syntax, with updated documentation in
   722 isar-ref manual.  Removed locales meta_term_syntax and
   723 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   724 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   725 directly in regular applications.
   726 
   727 * There is a new syntactic category "float_const" for signed decimal
   728 fractions (e.g. 123.45 or -123.45).
   729 
   730 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   731 interface with 'setup' command instead.
   732 
   733 * Command 'local_setup' is similar to 'setup', but operates on a local
   734 theory context.
   735 
   736 * The 'axiomatization' command now only works within a global theory
   737 context.  INCOMPATIBILITY.
   738 
   739 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   740 hypotheses.  Sorts required in the course of reasoning need to be
   741 covered by the constraints in the initial statement, completed by the
   742 type instance information of the background theory.  Non-trivial sort
   743 hypotheses, which rarely occur in practice, may be specified via
   744 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   745 
   746   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   747 
   748 The result contains an implicit sort hypotheses as before --
   749 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   750 normalization.
   751 
   752 * Generalized Isar history, with support for linear undo, direct state
   753 addressing etc.
   754 
   755 * Changed defaults for unify configuration options:
   756 
   757   unify_trace_bound = 50 (formerly 25)
   758   unify_search_bound = 60 (formerly 30)
   759 
   760 * Different bookkeeping for code equations (INCOMPATIBILITY):
   761 
   762   a) On theory merge, the last set of code equations for a particular
   763      constant is taken (in accordance with the policy applied by other
   764      parts of the code generator framework).
   765 
   766   b) Code equations stemming from explicit declarations (e.g. code
   767      attribute) gain priority over default code equations stemming
   768      from definition, primrec, fun etc.
   769 
   770 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   771 
   772 * Unified theorem tables for both code generators.  Thus [code
   773 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   774 
   775 * Command 'find_consts' searches for constants based on type and name
   776 patterns, e.g.
   777 
   778     find_consts "_ => bool"
   779 
   780 By default, matching is against subtypes, but it may be restricted to
   781 the whole type.  Searching by name is possible.  Multiple queries are
   782 conjunctive and queries may be negated by prefixing them with a
   783 hyphen:
   784 
   785     find_consts strict: "_ => bool" name: "Int" -"int => int"
   786 
   787 * New 'find_theorems' criterion "solves" matches theorems that
   788 directly solve the current goal (modulo higher-order unification).
   789 
   790 * Auto solve feature for main theorem statements: whenever a new goal
   791 is stated, "find_theorems solves" is called; any theorems that could
   792 solve the lemma directly are listed as part of the goal state.
   793 Cf. associated options in Proof General Isabelle settings menu,
   794 enabled by default, with reasonable timeout for pathological cases of
   795 higher-order unification.
   796 
   797 
   798 *** Document preparation ***
   799 
   800 * Antiquotation @{lemma} now imitates a regular terminal proof,
   801 demanding keyword 'by' and supporting the full method expression
   802 syntax just like the Isar command 'by'.
   803 
   804 
   805 *** HOL ***
   806 
   807 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   808 points Main and Complex_Main remain as before.
   809 
   810 * Logic image HOL-Plain provides a minimal HOL with the most important
   811 tools available (inductive, datatype, primrec, ...).  This facilitates
   812 experimentation and tool development.  Note that user applications
   813 (and library theories) should never refer to anything below theory
   814 Main, as before.
   815 
   816 * Logic image HOL-Main stops at theory Main, and thus facilitates
   817 experimentation due to shorter build times.
   818 
   819 * Logic image HOL-NSA contains theories of nonstandard analysis which
   820 were previously part of former HOL-Complex.  Entry point Hyperreal
   821 remains valid, but theories formerly using Complex_Main should now use
   822 new entry point Hypercomplex.
   823 
   824 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   825 Posix processes.  Avoids potentially expensive forking of the ML
   826 process.  New thread-based implementation also works on non-Unix
   827 platforms (Cygwin).  Provers are no longer hardwired, but defined
   828 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   829 commands are covered in the isar-ref manual.
   830 
   831 * Wrapper scripts for remote SystemOnTPTP service allows to use
   832 sledgehammer without local ATP installation (Vampire etc.). Other
   833 provers may be included via suitable ML wrappers, see also
   834 src/HOL/ATP_Linkup.thy.
   835 
   836 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   837 menu.
   838 
   839 * The metis method no longer fails because the theorem is too trivial
   840 (contains the empty clause).
   841 
   842 * The metis method now fails in the usual manner, rather than raising
   843 an exception, if it determines that it cannot prove the theorem.
   844 
   845 * Method "coherent" implements a prover for coherent logic (see also
   846 src/Tools/coherent.ML).
   847 
   848 * Constants "undefined" and "default" replace "arbitrary".  Usually
   849 "undefined" is the right choice to replace "arbitrary", though
   850 logically there is no difference.  INCOMPATIBILITY.
   851 
   852 * Command "value" now integrates different evaluation mechanisms.  The
   853 result of the first successful evaluation mechanism is printed.  In
   854 square brackets a particular named evaluation mechanisms may be
   855 specified (currently, [SML], [code] or [nbe]).  See further
   856 src/HOL/ex/Eval_Examples.thy.
   857 
   858 * Normalization by evaluation now allows non-leftlinear equations.
   859 Declare with attribute [code nbe].
   860 
   861 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   862 as the structured Isar versions "cases" and "induct", cf. the
   863 corresponding "cases" and "induct" attributes.  Mutual induction rules
   864 are now presented as a list of individual projections
   865 (e.g. foo_bar.inducts for types foo and bar); the old format with
   866 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   867 rare situations a different rule is selected --- notably nested tuple
   868 elimination instead of former prod.exhaust: use explicit (case_tac t
   869 rule: prod.exhaust) here.
   870 
   871 * Attributes "cases", "induct", "coinduct" support "del" option.
   872 
   873 * Removed fact "case_split_thm", which duplicates "case_split".
   874 
   875 * The option datatype has been moved to a new theory Option.  Renamed
   876 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   877 
   878 * New predicate "strict_mono" classifies strict functions on partial
   879 orders.  With strict functions on linear orders, reasoning about
   880 (in)equalities is facilitated by theorems "strict_mono_eq",
   881 "strict_mono_less_eq" and "strict_mono_less".
   882 
   883 * Some set operations are now proper qualified constants with
   884 authentic syntax.  INCOMPATIBILITY:
   885 
   886     op Int ~>   Set.Int
   887     op Un ~>    Set.Un
   888     INTER ~>    Set.INTER
   889     UNION ~>    Set.UNION
   890     Inter ~>    Set.Inter
   891     Union ~>    Set.Union
   892     {} ~>       Set.empty
   893     UNIV ~>     Set.UNIV
   894 
   895 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   896 theory Set.
   897 
   898 * Auxiliary class "itself" has disappeared -- classes without any
   899 parameter are treated as expected by the 'class' command.
   900 
   901 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   902 
   903 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   904 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   905 
   906 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   907 method "approximation".  It proves formulas on real values by using
   908 interval arithmetic.  In the formulas are also the transcendental
   909 functions sin, cos, tan, atan, ln, exp and the constant pi are
   910 allowed. For examples see
   911 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   912 
   913 * Theory "Reflection" now resides in HOL/Library.
   914 
   915 * Entry point to Word library now simply named "Word".
   916 INCOMPATIBILITY.
   917 
   918 * Made source layout more coherent with logical distribution
   919 structure:
   920 
   921     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   922     src/HOL/Library/Code_Message.thy ~> src/HOL/
   923     src/HOL/Library/GCD.thy ~> src/HOL/
   924     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   925     src/HOL/Library/Parity.thy ~> src/HOL/
   926     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   927     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   928     src/HOL/Real/Lubs.thy ~> src/HOL/
   929     src/HOL/Real/PReal.thy ~> src/HOL/
   930     src/HOL/Real/Rational.thy ~> src/HOL/
   931     src/HOL/Real/RComplete.thy ~> src/HOL/
   932     src/HOL/Real/RealDef.thy ~> src/HOL/
   933     src/HOL/Real/RealPow.thy ~> src/HOL/
   934     src/HOL/Real/Real.thy ~> src/HOL/
   935     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   936     src/HOL/Complex/Complex.thy ~> src/HOL/
   937     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   938     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   939     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   940     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   941     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   942     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   943     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   944     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   945     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   946     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   947     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   948     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   949     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   950     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   951     src/HOL/Real/Float ~> src/HOL/Library/
   952     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   953     src/HOL/Real/RealVector.thy ~> src/HOL/
   954 
   955     src/HOL/arith_data.ML ~> src/HOL/Tools
   956     src/HOL/hologic.ML ~> src/HOL/Tools
   957     src/HOL/simpdata.ML ~> src/HOL/Tools
   958     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   959     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   960     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   961     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   962     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   963     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   964     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   965 
   966     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   967     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   968     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   969     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   970     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   971     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   972 
   973 * If methods "eval" and "evaluation" encounter a structured proof
   974 state with !!/==>, only the conclusion is evaluated to True (if
   975 possible), avoiding strange error messages.
   976 
   977 * Method "sizechange" automates termination proofs using (a
   978 modification of) the size-change principle.  Requires SAT solver.  See
   979 src/HOL/ex/Termination.thy for examples.
   980 
   981 * Simplifier: simproc for let expressions now unfolds if bound
   982 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   983 
   984 * Method "arith": Linear arithmetic now ignores all inequalities when
   985 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   986 
   987 * New attribute "arith" for facts that should always be used
   988 automatically by arithmetic. It is intended to be used locally in
   989 proofs, e.g.
   990 
   991   assumes [arith]: "x > 0"
   992 
   993 Global usage is discouraged because of possible performance impact.
   994 
   995 * New classes "top" and "bot" with corresponding operations "top" and
   996 "bot" in theory Orderings; instantiation of class "complete_lattice"
   997 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   998 
   999 * Changed definition lemma "less_fun_def" in order to provide an
  1000 instance for preorders on functions; use lemma "less_le" instead.
  1001 INCOMPATIBILITY.
  1002 
  1003 * Theory Orderings: class "wellorder" moved here, with explicit
  1004 induction rule "less_induct" as assumption.  For instantiation of
  1005 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  1006 INCOMPATIBILITY.
  1007 
  1008 * Theory Orderings: added class "preorder" as superclass of "order".
  1009 INCOMPATIBILITY: Instantiation proofs for order, linorder
  1010 etc. slightly changed.  Some theorems named order_class.* now named
  1011 preorder_class.*.
  1012 
  1013 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  1014 "diag" to "Id_on".
  1015 
  1016 * Theory Finite_Set: added a new fold combinator of type
  1017 
  1018   ('a => 'b => 'b) => 'b => 'a set => 'b
  1019 
  1020 Occasionally this is more convenient than the old fold combinator
  1021 which is now defined in terms of the new one and renamed to
  1022 fold_image.
  1023 
  1024 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  1025 and "ring_simps" have been replaced by "algebra_simps" (which can be
  1026 extended with further lemmas!).  At the moment both still exist but
  1027 the former will disappear at some point.
  1028 
  1029 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  1030 class recpower.  Type-specific simp rules for various recpower types
  1031 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  1032 
  1033 rat_power_0    -> power_0
  1034 rat_power_Suc  -> power_Suc
  1035 realpow_0      -> power_0
  1036 realpow_Suc    -> power_Suc
  1037 complexpow_0   -> power_0
  1038 complexpow_Suc -> power_Suc
  1039 power_poly_0   -> power_0
  1040 power_poly_Suc -> power_Suc
  1041 
  1042 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  1043 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  1044 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  1045 of lemmas from Divides has been generalized from nat to class
  1046 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  1047 renames resulting from duplicate elimination:
  1048 
  1049     dvd_def_mod ~>          dvd_eq_mod_eq_0
  1050     zero_dvd_iff ~>         dvd_0_left_iff
  1051     dvd_0 ~>                dvd_0_right
  1052     DIVISION_BY_ZERO_DIV ~> div_by_0
  1053     DIVISION_BY_ZERO_MOD ~> mod_by_0
  1054     mult_div ~>             div_mult_self2_is_id
  1055     mult_mod ~>             mod_mult_self2_is_0
  1056 
  1057 * Theory IntDiv: removed many lemmas that are instances of class-based
  1058 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  1059 rename old lemmas as follows:
  1060 
  1061 dvd_diff               -> nat_dvd_diff
  1062 dvd_zminus_iff         -> dvd_minus_iff
  1063 mod_add1_eq            -> mod_add_eq
  1064 mod_mult1_eq           -> mod_mult_right_eq
  1065 mod_mult1_eq'          -> mod_mult_left_eq
  1066 mod_mult_distrib_mod   -> mod_mult_eq
  1067 nat_mod_add_left_eq    -> mod_add_left_eq
  1068 nat_mod_add_right_eq   -> mod_add_right_eq
  1069 nat_mod_div_trivial    -> mod_div_trivial
  1070 nat_mod_mod_trivial    -> mod_mod_trivial
  1071 zdiv_zadd_self1        -> div_add_self1
  1072 zdiv_zadd_self2        -> div_add_self2
  1073 zdiv_zmult_self1       -> div_mult_self2_is_id
  1074 zdiv_zmult_self2       -> div_mult_self1_is_id
  1075 zdvd_triv_left         -> dvd_triv_left
  1076 zdvd_triv_right        -> dvd_triv_right
  1077 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  1078 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  1079 zmod_zadd_left_eq      -> mod_add_left_eq
  1080 zmod_zadd_right_eq     -> mod_add_right_eq
  1081 zmod_zadd_self1        -> mod_add_self1
  1082 zmod_zadd_self2        -> mod_add_self2
  1083 zmod_zadd1_eq          -> mod_add_eq
  1084 zmod_zdiff1_eq         -> mod_diff_eq
  1085 zmod_zdvd_zmod         -> mod_mod_cancel
  1086 zmod_zmod_cancel       -> mod_mod_cancel
  1087 zmod_zmult_self1       -> mod_mult_self2_is_0
  1088 zmod_zmult_self2       -> mod_mult_self1_is_0
  1089 zmod_1                 -> mod_by_1
  1090 zdiv_1                 -> div_by_1
  1091 zdvd_abs1              -> abs_dvd_iff
  1092 zdvd_abs2              -> dvd_abs_iff
  1093 zdvd_refl              -> dvd_refl
  1094 zdvd_trans             -> dvd_trans
  1095 zdvd_zadd              -> dvd_add
  1096 zdvd_zdiff             -> dvd_diff
  1097 zdvd_zminus_iff        -> dvd_minus_iff
  1098 zdvd_zminus2_iff       -> minus_dvd_iff
  1099 zdvd_zmultD            -> dvd_mult_right
  1100 zdvd_zmultD2           -> dvd_mult_left
  1101 zdvd_zmult_mono        -> mult_dvd_mono
  1102 zdvd_0_right           -> dvd_0_right
  1103 zdvd_0_left            -> dvd_0_left_iff
  1104 zdvd_1_left            -> one_dvd
  1105 zminus_dvd_iff         -> minus_dvd_iff
  1106 
  1107 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  1108 
  1109 * The real numbers offer decimal input syntax: 12.34 is translated
  1110 into 1234/10^2. This translation is not reversed upon output.
  1111 
  1112 * Theory Library/Polynomial defines an abstract type 'a poly of
  1113 univariate polynomials with coefficients of type 'a.  In addition to
  1114 the standard ring operations, it also supports div and mod.  Code
  1115 generation is also supported, using list-style constructors.
  1116 
  1117 * Theory Library/Inner_Product defines a class of real_inner for real
  1118 inner product spaces, with an overloaded operation inner :: 'a => 'a
  1119 => real.  Class real_inner is a subclass of real_normed_vector from
  1120 theory RealVector.
  1121 
  1122 * Theory Library/Product_Vector provides instances for the product
  1123 type 'a * 'b of several classes from RealVector and Inner_Product.
  1124 Definitions of addition, subtraction, scalar multiplication, norms,
  1125 and inner products are included.
  1126 
  1127 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  1128 addition to the field operations, numerals and case syntax are also
  1129 supported.
  1130 
  1131 * Theory Library/Diagonalize provides constructive version of Cantor's
  1132 first diagonalization argument.
  1133 
  1134 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  1135 zlcm (for int); carried together from various gcd/lcm developements in
  1136 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  1137 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  1138 may recover tupled syntax as follows:
  1139 
  1140     hide (open) const gcd
  1141     abbreviation gcd where
  1142       "gcd == (%(a, b). GCD.gcd a b)"
  1143     notation (output)
  1144       GCD.gcd ("gcd '(_, _')")
  1145 
  1146 The same works for lcm, zgcd, zlcm.
  1147 
  1148 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  1149 instantiations for algebraic structures.  Removed some duplicate
  1150 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  1151 
  1152 * ML antiquotation @{code} takes a constant as argument and generates
  1153 corresponding code in background and inserts name of the corresponding
  1154 resulting ML value/function/datatype constructor binding in place.
  1155 All occurrences of @{code} with a single ML block are generated
  1156 simultaneously.  Provides a generic and safe interface for
  1157 instrumentalizing code generation.  See
  1158 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1159 In future you ought to refrain from ad-hoc compiling generated SML
  1160 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1161 cannot refer to constants for which user-defined serializations are
  1162 set.  Refer to the corresponding ML counterpart directly in that
  1163 cases.
  1164 
  1165 * Command 'rep_datatype': instead of theorem names the command now
  1166 takes a list of terms denoting the constructors of the type to be
  1167 represented as datatype.  The characteristic theorems have to be
  1168 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1169 have disappeared in favour of existing ones:
  1170 
  1171     unit_induct                 ~> unit.induct
  1172     prod_induct                 ~> prod.induct
  1173     sum_induct                  ~> sum.induct
  1174     Suc_Suc_eq                  ~> nat.inject
  1175     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1176 
  1177 
  1178 *** HOL-Algebra ***
  1179 
  1180 * New locales for orders and lattices where the equivalence relation
  1181 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1182 locales use a record structure with field eq for the equivalence.
  1183 
  1184 * New theory of factorial domains.
  1185 
  1186 * Units_l_inv and Units_r_inv are now simp rules by default.
  1187 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1188 and/or r_inv will now also require deletion of these lemmas.
  1189 
  1190 * Renamed the following theorems, INCOMPATIBILITY:
  1191 
  1192 UpperD ~> Upper_memD
  1193 LowerD ~> Lower_memD
  1194 least_carrier ~> least_closed
  1195 greatest_carrier ~> greatest_closed
  1196 greatest_Lower_above ~> greatest_Lower_below
  1197 one_zero ~> carrier_one_zero
  1198 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1199 
  1200 
  1201 *** HOL-Nominal ***
  1202 
  1203 * Nominal datatypes can now contain type-variables.
  1204 
  1205 * Commands 'nominal_inductive' and 'equivariance' work with local
  1206 theory targets.
  1207 
  1208 * Nominal primrec can now works with local theory targets and its
  1209 specification syntax now conforms to the general format as seen in
  1210 'inductive' etc.
  1211 
  1212 * Method "perm_simp" honours the standard simplifier attributes
  1213 (no_asm), (no_asm_use) etc.
  1214 
  1215 * The new predicate #* is defined like freshness, except that on the
  1216 left hand side can be a set or list of atoms.
  1217 
  1218 * Experimental command 'nominal_inductive2' derives strong induction
  1219 principles for inductive definitions.  In contrast to
  1220 'nominal_inductive', which can only deal with a fixed number of
  1221 binders, it can deal with arbitrary expressions standing for sets of
  1222 atoms to be avoided.  The only inductive definition we have at the
  1223 moment that needs this generalisation is the typing rule for Lets in
  1224 the algorithm W:
  1225 
  1226  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1227  -----------------------------------------------------------------
  1228          Gamma |- Let x be t1 in t2 : T2
  1229 
  1230 In this rule one wants to avoid all the binders that are introduced by
  1231 "close Gamma T1".  We are looking for other examples where this
  1232 feature might be useful.  Please let us know.
  1233 
  1234 
  1235 *** HOLCF ***
  1236 
  1237 * Reimplemented the simplification procedure for proving continuity
  1238 subgoals.  The new simproc is extensible; users can declare additional
  1239 continuity introduction rules with the attribute [cont2cont].
  1240 
  1241 * The continuity simproc now uses a different introduction rule for
  1242 solving continuity subgoals on terms with lambda abstractions.  In
  1243 some rare cases the new simproc may fail to solve subgoals that the
  1244 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1245 Potential INCOMPATIBILITY.
  1246 
  1247 * Command 'fixrec': specification syntax now conforms to the general
  1248 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1249 examples.  INCOMPATIBILITY.
  1250 
  1251 
  1252 *** ZF ***
  1253 
  1254 * Proof of Zorn's Lemma for partial orders.
  1255 
  1256 
  1257 *** ML ***
  1258 
  1259 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1260 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1261 depends on multithreading, so timouts will not work before Poly/ML
  1262 5.2.1!
  1263 
  1264 * High-level support for concurrent ML programming, see
  1265 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1266 particularly convenient to organize independent functional
  1267 computations.  The concept of "synchronized variables" provides a
  1268 higher-order interface for components with shared state, avoiding the
  1269 delicate details of mutexes and condition variables.  (Requires
  1270 Poly/ML 5.2.1 or later.)
  1271 
  1272 * ML bindings produced via Isar commands are stored within the Isar
  1273 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1274 become thread-safe and work with undo as expected (concerning
  1275 top-level bindings, not side-effects on global references).
  1276 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1277 compiler at runtime; really global bindings need to be given outside a
  1278 theory.  (Requires Poly/ML 5.2 or later.)
  1279 
  1280 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1281 context.  Top-level ML bindings are stored within the proof context in
  1282 a purely sequential fashion, disregarding the nested proof structure.
  1283 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1284 proof.  (Requires Poly/ML 5.2 or later.)
  1285 
  1286 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1287 and Method.setup, as well as Isar commands 'attribute_setup' and
  1288 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1289 existing code accordingly, or use plain 'setup' together with old
  1290 Method.add_method.
  1291 
  1292 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1293 to 'a -> thm, while results are always tagged with an authentic oracle
  1294 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1295 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1296 accordingly.  Note that extra performance may be gained by producing
  1297 the cterm carefully, avoiding slow Thm.cterm_of.
  1298 
  1299 * Simplified interface for defining document antiquotations via
  1300 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1301 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1302 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1303 examples.
  1304 
  1305 * More systematic treatment of long names, abstract name bindings, and
  1306 name space operations.  Basic operations on qualified names have been
  1307 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1308 Long_Name.append.  Old type bstring has been mostly replaced by
  1309 abstract type binding (see structure Binding), which supports precise
  1310 qualification by packages and local theory targets, as well as proper
  1311 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1312 bstring values into Binding.name, or better pass through abstract
  1313 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1314 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1315 
  1316 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1317 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1318 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1319 
  1320 * Disposed old type and term read functions (Sign.read_def_typ,
  1321 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1322 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1323 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1324 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1325 resort for legacy applications.
  1326 
  1327 * Disposed old declarations, tactics, tactic combinators that refer to
  1328 the simpset or claset of an implicit theory (such as Addsimps,
  1329 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1330 embedded ML text, or local_simpset_of with a proper context passed as
  1331 explicit runtime argument.
  1332 
  1333 * Rules and tactics that read instantiations (read_instantiate,
  1334 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1335 context, which is required for parsing and type-checking.  Moreover,
  1336 the variables are specified as plain indexnames, not string encodings
  1337 thereof.  INCOMPATIBILITY.
  1338 
  1339 * Generic Toplevel.add_hook interface allows to analyze the result of
  1340 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1341 for theorem dependency output of transactions resulting in a new
  1342 theory state.
  1343 
  1344 * ML antiquotations: block-structured compilation context indicated by
  1345 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1346 
  1347   @{binding name}                         - basic name binding
  1348   @{let ?pat = term}                      - term abbreviation (HO matching)
  1349   @{note name = fact}                     - fact abbreviation
  1350   @{thm fact}                             - singleton fact (with attributes)
  1351   @{thms fact}                            - general fact (with attributes)
  1352   @{lemma prop by method}                 - singleton goal
  1353   @{lemma prop by meth1 meth2}            - singleton goal
  1354   @{lemma prop1 ... propN by method}      - general goal
  1355   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1356   @{lemma (open) ...}                     - open derivation
  1357 
  1358 
  1359 *** System ***
  1360 
  1361 * The Isabelle "emacs" tool provides a specific interface to invoke
  1362 Proof General / Emacs, with more explicit failure if that is not
  1363 installed (the old isabelle-interface script silently falls back on
  1364 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1365 installation location of the Proof General distribution.
  1366 
  1367 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1368 the Isabelle process into a JVM/Scala application.  See
  1369 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1370 process wrapper has been discontinued.)
  1371 
  1372 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1373 
  1374 * Various status messages (with exact source position information) are
  1375 emitted, if proper markup print mode is enabled.  This allows
  1376 user-interface components to provide detailed feedback on internal
  1377 prover operations.
  1378 
  1379 
  1380 
  1381 New in Isabelle2008 (June 2008)
  1382 -------------------------------
  1383 
  1384 *** General ***
  1385 
  1386 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1387 and updated, with formally checked references as hyperlinks.
  1388 
  1389 * Theory loader: use_thy (and similar operations) no longer set the
  1390 implicit ML context, which was occasionally hard to predict and in
  1391 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1392 provides a proper context already.
  1393 
  1394 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1395 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1396 'use' within a theory file will do the job.
  1397 
  1398 * Name space merge now observes canonical order, i.e. the second space
  1399 is inserted into the first one, while existing entries in the first
  1400 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1401 swap theory imports.
  1402 
  1403 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1404 INCOMPATIBILITY in identifier syntax etc.
  1405 
  1406 * Outer syntax: string tokens no longer admit escaped white space,
  1407 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1408 white space without escapes.
  1409 
  1410 * Outer syntax: string tokens may contain arbitrary character codes
  1411 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1412 "foo_bar".
  1413 
  1414 
  1415 *** Pure ***
  1416 
  1417 * Context-dependent token translations.  Default setup reverts locally
  1418 fixed variables, and adds hilite markup for undeclared frees.
  1419 
  1420 * Unused theorems can be found using the new command 'unused_thms'.
  1421 There are three ways of invoking it:
  1422 
  1423 (1) unused_thms
  1424      Only finds unused theorems in the current theory.
  1425 
  1426 (2) unused_thms thy_1 ... thy_n -
  1427      Finds unused theorems in the current theory and all of its ancestors,
  1428      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1429 
  1430 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1431      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1432      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1433      their ancestors.
  1434 
  1435 In order to increase the readability of the list produced by
  1436 unused_thms, theorems that have been created by a particular instance
  1437 of a theory command such as 'inductive' or 'function' are considered
  1438 to belong to the same "group", meaning that if at least one theorem in
  1439 this group is used, the other theorems in the same group are no longer
  1440 reported as unused.  Moreover, if all theorems in the group are
  1441 unused, only one theorem in the group is displayed.
  1442 
  1443 Note that proof objects have to be switched on in order for
  1444 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1445 usually the case when using Proof General with the default settings).
  1446 
  1447 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1448 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1449 duplicate fact bindings, or even accidental fact duplications.  Note
  1450 that tools may maintain dynamically scoped facts systematically, using
  1451 PureThy.add_thms_dynamic.
  1452 
  1453 * Command 'hide' now allows to hide from "fact" name space as well.
  1454 
  1455 * Eliminated destructive theorem database, simpset, claset, and
  1456 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1457 update of theories within ML code.
  1458 
  1459 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1460 INCOMPATIBILITY, object-logics depending on former Pure require
  1461 additional setup PureThy.old_appl_syntax_setup; object-logics
  1462 depending on former CPure need to refer to Pure.
  1463 
  1464 * Commands 'use' and 'ML' are now purely functional, operating on
  1465 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1466 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1467 INCOMPATIBILITY.
  1468 
  1469 * Command 'setup': discontinued implicit version with ML reference.
  1470 
  1471 * Instantiation target allows for simultaneous specification of class
  1472 instance operations together with an instantiation proof.
  1473 Type-checking phase allows to refer to class operations uniformly.
  1474 See src/HOL/Complex/Complex.thy for an Isar example and
  1475 src/HOL/Library/Eval.thy for an ML example.
  1476 
  1477 * Indexing of literal facts: be more serious about including only
  1478 facts from the visible specification/proof context, but not the
  1479 background context (locale etc.).  Affects `prop` notation and method
  1480 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1481 situations.
  1482 
  1483 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1484 "(open)" option, which used to expose internal bound variables to the
  1485 proof text.
  1486 
  1487 * Isar statements: removed obsolete case "rule_context".
  1488 INCOMPATIBILITY, better use explicit fixes/assumes.
  1489 
  1490 * Locale proofs: default proof step now includes 'unfold_locales';
  1491 hence 'proof' without argument may be used to unfold locale
  1492 predicates.
  1493 
  1494 
  1495 *** Document preparation ***
  1496 
  1497 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1498 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1499 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1500 spot); renamed link color from "darkblue" to "linkcolor" (default
  1501 value unchanged, can be redefined via \definecolor); no longer sets
  1502 "a4paper" option (unnecessary or even intrusive).
  1503 
  1504 * Antiquotation @{lemma A method} proves proposition A by the given
  1505 method (either a method name or a method name plus (optional) method
  1506 arguments in parentheses) and prints A just like @{prop A}.
  1507 
  1508 
  1509 *** HOL ***
  1510 
  1511 * New primrec package.  Specification syntax conforms in style to
  1512 definition/function/....  No separate induction rule is provided.  The
  1513 "primrec" command distinguishes old-style and new-style specifications
  1514 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1515 When adjusting theories, beware: constants stemming from new-style
  1516 primrec specifications have authentic syntax.
  1517 
  1518 * Metis prover is now an order of magnitude faster, and also works
  1519 with multithreading.
  1520 
  1521 * Metis: the maximum number of clauses that can be produced from a
  1522 theorem is now given by the attribute max_clauses.  Theorems that
  1523 exceed this number are ignored, with a warning printed.
  1524 
  1525 * Sledgehammer no longer produces structured proofs by default. To
  1526 enable, declare [[sledgehammer_full = true]].  Attributes
  1527 reconstruction_modulus, reconstruction_sorts renamed
  1528 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1529 
  1530 * Method "induct_scheme" derives user-specified induction rules
  1531 from well-founded induction and completeness of patterns. This factors
  1532 out some operations that are done internally by the function package
  1533 and makes them available separately.  See
  1534 src/HOL/ex/Induction_Scheme.thy for examples.
  1535 
  1536 * More flexible generation of measure functions for termination
  1537 proofs: Measure functions can be declared by proving a rule of the
  1538 form "is_measure f" and giving it the [measure_function] attribute.
  1539 The "is_measure" predicate is logically meaningless (always true), and
  1540 just guides the heuristic.  To find suitable measure functions, the
  1541 termination prover sets up the goal "is_measure ?f" of the appropriate
  1542 type and generates all solutions by prolog-style backwards proof using
  1543 the declared rules.
  1544 
  1545 This setup also deals with rules like 
  1546 
  1547   "is_measure f ==> is_measure (list_size f)"
  1548 
  1549 which accommodates nested datatypes that recurse through lists.
  1550 Similar rules are predeclared for products and option types.
  1551 
  1552 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1553 
  1554   INCOMPATIBILITIES:
  1555 
  1556   - Definitions of overloaded constants on sets have to be replaced by
  1557     definitions on => and bool.
  1558 
  1559   - Some definitions of overloaded operators on sets can now be proved
  1560     using the definitions of the operators on => and bool.  Therefore,
  1561     the following theorems have been renamed:
  1562 
  1563       subset_def   -> subset_eq
  1564       psubset_def  -> psubset_eq
  1565       set_diff_def -> set_diff_eq
  1566       Compl_def    -> Compl_eq
  1567       Sup_set_def  -> Sup_set_eq
  1568       Inf_set_def  -> Inf_set_eq
  1569       sup_set_def  -> sup_set_eq
  1570       inf_set_def  -> inf_set_eq
  1571 
  1572   - Due to the incompleteness of the HO unification algorithm, some
  1573     rules such as subst may require manual instantiation, if some of
  1574     the unknowns in the rule is a set.
  1575 
  1576   - Higher order unification and forward proofs:
  1577     The proof pattern
  1578 
  1579       have "P (S::'a set)" <...>
  1580       then have "EX S. P S" ..
  1581 
  1582     no longer works (due to the incompleteness of the HO unification
  1583     algorithm) and must be replaced by the pattern
  1584 
  1585       have "EX S. P S"
  1586       proof
  1587         show "P S" <...>
  1588       qed
  1589 
  1590   - Calculational reasoning with subst (or similar rules):
  1591     The proof pattern
  1592 
  1593       have "P (S::'a set)" <...>
  1594       also have "S = T" <...>
  1595       finally have "P T" .
  1596 
  1597     no longer works (for similar reasons as the previous example) and
  1598     must be replaced by something like
  1599 
  1600       have "P (S::'a set)" <...>
  1601       moreover have "S = T" <...>
  1602       ultimately have "P T" by simp
  1603 
  1604   - Tactics or packages written in ML code:
  1605     Code performing pattern matching on types via
  1606 
  1607       Type ("set", [T]) => ...
  1608 
  1609     must be rewritten. Moreover, functions like strip_type or
  1610     binder_types no longer return the right value when applied to a
  1611     type of the form
  1612 
  1613       T1 => ... => Tn => U => bool
  1614 
  1615     rather than
  1616 
  1617       T1 => ... => Tn => U set
  1618 
  1619 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1620 Wellfounded_Relations to theory Wellfounded.
  1621 
  1622 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1623 
  1624 * Class finite no longer treats UNIV as class parameter.  Use class
  1625 enum from theory Library/Enum instead to achieve a similar effect.
  1626 INCOMPATIBILITY.
  1627 
  1628 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1629 and "Cons".  INCOMPATIBILITY.
  1630 
  1631 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1632 Potential INCOMPATIBILITY.
  1633 
  1634 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1635 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1636 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1637 
  1638 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1639 the same name in theory Orderings:
  1640 
  1641   less_trans
  1642   less_linear
  1643   le_imp_less_or_eq
  1644   le_less_trans
  1645   less_le_trans
  1646   less_not_sym
  1647   less_asym
  1648 
  1649 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1650 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1651 and different variable names.
  1652 
  1653 * Library/Option_ord.thy: Canonical order on option type.
  1654 
  1655 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1656 finite maps.
  1657 
  1658 * Library/Countable.thy: Type class for countable types.
  1659 
  1660 * Theory Int: The representation of numerals has changed.  The infix
  1661 operator BIT and the bit datatype with constructors B0 and B1 have
  1662 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1663 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1664 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1665 accordingly.
  1666 
  1667 * Theory Nat: definition of <= and < on natural numbers no longer
  1668 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1669 le_def and less_def have disappeared.  Consider lemmas not_less
  1670 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1671 
  1672 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1673 (whose purpose mainly is for various fold_set functionals) have been
  1674 abandoned in favor of the existing algebraic classes
  1675 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1676 lower_semilattice (resp. upper_semilattice) and linorder.
  1677 INCOMPATIBILITY.
  1678 
  1679 * Theory Transitive_Closure: induct and cases rules now declare proper
  1680 case_names ("base" and "step").  INCOMPATIBILITY.
  1681 
  1682 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1683 lattices.  The form set-specific version is available as
  1684 Inductive.lfp_ordinal_induct_set.
  1685 
  1686 * Renamed theorems "power.simps" to "power_int.simps".
  1687 INCOMPATIBILITY.
  1688 
  1689 * Class semiring_div provides basic abstract properties of semirings
  1690 with division and modulo operations.  Subsumes former class dvd_mod.
  1691 
  1692 * Merged theories IntDef, Numeral and IntArith into unified theory
  1693 Int.  INCOMPATIBILITY.
  1694 
  1695 * Theory Library/Code_Index: type "index" now represents natural
  1696 numbers rather than integers.  INCOMPATIBILITY.
  1697 
  1698 * New class "uminus" with operation "uminus" (split of from class
  1699 "minus" which now only has operation "minus", binary).
  1700 INCOMPATIBILITY.
  1701 
  1702 * Constants "card", "internal_split", "option_map" now with authentic
  1703 syntax.  INCOMPATIBILITY.
  1704 
  1705 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1706 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1707 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1708 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1709 Sup_set_def, le_def, less_def, option_map_def now with object
  1710 equality.  INCOMPATIBILITY.
  1711 
  1712 * Records. Removed K_record, and replaced it by pure lambda term
  1713 %x. c. The simplifier setup is now more robust against eta expansion.
  1714 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1715 
  1716 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1717 
  1718 * Library/ListVector: new theory of arithmetic vector operations.
  1719 
  1720 * Library/Order_Relation: new theory of various orderings as sets of
  1721 pairs.  Defines preorders, partial orders, linear orders and
  1722 well-orders on sets and on types.
  1723 
  1724 
  1725 *** ZF ***
  1726 
  1727 * Renamed some theories to allow to loading both ZF and HOL in the
  1728 same session:
  1729 
  1730   Datatype  -> Datatype_ZF
  1731   Inductive -> Inductive_ZF
  1732   Int       -> Int_ZF
  1733   IntDiv    -> IntDiv_ZF
  1734   Nat       -> Nat_ZF
  1735   List      -> List_ZF
  1736   Main      -> Main_ZF
  1737 
  1738 INCOMPATIBILITY: ZF theories that import individual theories below
  1739 Main might need to be adapted.  Regular theory Main is still
  1740 available, as trivial extension of Main_ZF.
  1741 
  1742 
  1743 *** ML ***
  1744 
  1745 * ML within Isar: antiquotation @{const name} or @{const
  1746 name(typargs)} produces statically-checked Const term.
  1747 
  1748 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1749 (of the same name).  Removed obsolete print command.
  1750 
  1751 * Removed obsolete "use_legacy_bindings" function.
  1752 
  1753 * The ``print mode'' is now a thread-local value derived from a global
  1754 template (the former print_mode reference), thus access becomes
  1755 non-critical.  The global print_mode reference is for session
  1756 management only; user-code should use print_mode_value,
  1757 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1758 
  1759 * Functions system/system_out provide a robust way to invoke external
  1760 shell commands, with propagation of interrupts (requires Poly/ML
  1761 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1762 
  1763 
  1764 *** System ***
  1765 
  1766 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1767 in accordance with Proof General 3.7, which prefers GNU emacs.
  1768 
  1769 * isatool tty runs Isabelle process with plain tty interaction;
  1770 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1771 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1772 
  1773 * isatool browser now works with Cygwin as well, using general
  1774 "javapath" function defined in Isabelle process environment.
  1775 
  1776 * YXML notation provides a simple and efficient alternative to
  1777 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1778 isatool yxml as described in the Isabelle system manual.
  1779 
  1780 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1781 provides general wrapper for managing an Isabelle process in a robust
  1782 fashion, with ``cooked'' output from stdin/stderr.
  1783 
  1784 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1785 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1786 
  1787 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1788 way of changing the user's settings is via
  1789 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1790 script.
  1791 
  1792 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1793 cores of the underlying machine, which is a good starting point for
  1794 optimal performance tuning.  The corresponding usedir option -M allows
  1795 "max" as an alias for "0".  WARNING: does not work on certain versions
  1796 of Mac OS (with Poly/ML 5.1).
  1797 
  1798 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1799 adverse effect of Isabelle flooding interactive front-ends (notably
  1800 ProofGeneral / XEmacs).
  1801 
  1802 
  1803 
  1804 New in Isabelle2007 (November 2007)
  1805 -----------------------------------
  1806 
  1807 *** General ***
  1808 
  1809 * More uniform information about legacy features, notably a
  1810 warning/error of "Legacy feature: ...", depending on the state of the
  1811 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1812 legacy features will disappear eventually.
  1813 
  1814 * Theory syntax: the header format ``theory A = B + C:'' has been
  1815 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1816 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1817 
  1818 * Theory syntax: the old non-Isar theory file format has been
  1819 discontinued altogether.  Note that ML proof scripts may still be used
  1820 with Isar theories; migration is usually quite simple with the ML
  1821 function use_legacy_bindings.  INCOMPATIBILITY.
  1822 
  1823 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1824 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1825 quotes.
  1826 
  1827 * Theory loader: be more serious about observing the static theory
  1828 header specifications (including optional directories), but not the
  1829 accidental file locations of previously successful loads.  The strict
  1830 update policy of former update_thy is now already performed by
  1831 use_thy, so the former has been removed; use_thys updates several
  1832 theories simultaneously, just as 'imports' within a theory header
  1833 specification, but without merging the results.  Potential
  1834 INCOMPATIBILITY: may need to refine theory headers and commands
  1835 ROOT.ML which depend on load order.
  1836 
  1837 * Theory loader: optional support for content-based file
  1838 identification, instead of the traditional scheme of full physical
  1839 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1840 (cf. the system manual).  The new scheme allows to work with
  1841 non-finished theories in persistent session images, such that source
  1842 files may be moved later on without requiring reloads.
  1843 
  1844 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1845 file (with the same base name as the theory) are considered a legacy
  1846 feature, which will disappear eventually. Even now, the theory loader
  1847 no longer maintains dependencies on such files.
  1848 
  1849 * Syntax: the scope for resolving ambiguities via type-inference is
  1850 now limited to individual terms, instead of whole simultaneous
  1851 specifications as before. This greatly reduces the complexity of the
  1852 syntax module and improves flexibility by separating parsing and
  1853 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1854 'fixes' etc.) are required in rare situations.
  1855 
  1856 * Syntax: constants introduced by new-style packages ('definition',
  1857 'abbreviation' etc.) are passed through the syntax module in
  1858 ``authentic mode''. This means that associated mixfix annotations
  1859 really stick to such constants, independently of potential name space
  1860 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1861 trees are represented slightly differently, may need to adapt syntax
  1862 translations accordingly. Use CONST marker in 'translations' and
  1863 @{const_syntax} antiquotation in 'parse_translation' etc.
  1864 
  1865 * Legacy goal package: reduced interface to the bare minimum required
  1866 to keep existing proof scripts running.  Most other user-level
  1867 functions are now part of the OldGoals structure, which is *not* open
  1868 by default (consider isatool expandshort before open OldGoals).
  1869 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1870 these tend to cause confusion about the actual goal (!) context being
  1871 used here, which is not necessarily the same as the_context().
  1872 
  1873 * Command 'find_theorems': supports "*" wild-card in "name:"
  1874 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1875 support a specific search form (see ProofGeneral/CHANGES).
  1876 
  1877 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1878 by default, which means that "prems" (and also "fixed variables") are
  1879 suppressed from proof state output.  Note that the ProofGeneral
  1880 settings mechanism allows to change and save options persistently, but
  1881 older versions of Isabelle will fail to start up if a negative prems
  1882 limit is imposed.
  1883 
  1884 * Local theory targets may be specified by non-nested blocks of
  1885 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1886 contain definitions, theorems etc., including any derived mechanism
  1887 that has been implemented on top of these primitives.  This concept
  1888 generalizes the existing ``theorem (in ...)'' towards more versatility
  1889 and scalability.
  1890 
  1891 * Proof General interface: proper undo of final 'end' command;
  1892 discontinued Isabelle/classic mode (ML proof scripts).
  1893 
  1894 
  1895 *** Document preparation ***
  1896 
  1897 * Added antiquotation @{theory name} which prints the given name,
  1898 after checking that it refers to a valid ancestor theory in the
  1899 current context.
  1900 
  1901 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1902 check the given source text as ML type/structure, printing verbatim.
  1903 
  1904 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1905 "c args == rhs" given in the current context.  (Any number of
  1906 arguments may be given on the LHS.)
  1907 
  1908 
  1909 *** Pure ***
  1910 
  1911 * The 'class' package offers a combination of axclass and locale to
  1912 achieve Haskell-like type classes in Isabelle.  Definitions and
  1913 theorems within a class context produce both relative results (with
  1914 implicit parameters according to the locale context), and polymorphic
  1915 constants with qualified polymorphism (according to the class
  1916 context).  Within the body context of a 'class' target, a separate
  1917 syntax layer ("user space type system") takes care of converting
  1918 between global polymorphic consts and internal locale representation.
  1919 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1920 "isatool doc classes" provides a tutorial.
  1921 
  1922 * Generic code generator framework allows to generate executable
  1923 code for ML and Haskell (including Isabelle classes).  A short usage
  1924 sketch:
  1925 
  1926     internal compilation:
  1927         export_code <list of constants (term syntax)> in SML
  1928     writing SML code to a file:
  1929         export_code <list of constants (term syntax)> in SML <filename>
  1930     writing OCaml code to a file:
  1931         export_code <list of constants (term syntax)> in OCaml <filename>
  1932     writing Haskell code to a bunch of files:
  1933         export_code <list of constants (term syntax)> in Haskell <filename>
  1934 
  1935     evaluating closed propositions to True/False using code generation:
  1936         method ``eval''
  1937 
  1938 Reasonable default setup of framework in HOL.
  1939 
  1940 Theorem attributs for selecting and transforming function equations theorems:
  1941 
  1942     [code fun]:        select a theorem as function equation for a specific constant
  1943     [code fun del]:    deselect a theorem as function equation for a specific constant
  1944     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1945     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1946 
  1947 User-defined serializations (target in {SML, OCaml, Haskell}):
  1948 
  1949     code_const <and-list of constants (term syntax)>
  1950       {(target) <and-list of const target syntax>}+
  1951 
  1952     code_type <and-list of type constructors>
  1953       {(target) <and-list of type target syntax>}+
  1954 
  1955     code_instance <and-list of instances>
  1956       {(target)}+
  1957         where instance ::= <type constructor> :: <class>
  1958 
  1959     code_class <and_list of classes>
  1960       {(target) <and-list of class target syntax>}+
  1961         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1962 
  1963 code_instance and code_class only are effective to target Haskell.
  1964 
  1965 For example usage see src/HOL/ex/Codegenerator.thy and
  1966 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1967 generation from Isabelle/HOL theories is available via "isatool doc
  1968 codegen".
  1969 
  1970 * Code generator: consts in 'consts_code' Isar commands are now
  1971 referred to by usual term syntax (including optional type
  1972 annotations).
  1973 
  1974 * Command 'no_translations' removes translation rules from theory
  1975 syntax.
  1976 
  1977 * Overloaded definitions are now actually checked for acyclic
  1978 dependencies.  The overloading scheme is slightly more general than
  1979 that of Haskell98, although Isabelle does not demand an exact
  1980 correspondence to type class and instance declarations.
  1981 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1982 exotic versions of overloading -- at the discretion of the user!
  1983 
  1984 Polymorphic constants are represented via type arguments, i.e. the
  1985 instantiation that matches an instance against the most general
  1986 declaration given in the signature.  For example, with the declaration
  1987 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1988 as c(nat).  Overloading is essentially simultaneous structural
  1989 recursion over such type arguments.  Incomplete specification patterns
  1990 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1991 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1992 Command 'print_theory' outputs the normalized system of recursive
  1993 equations, see section "definitions".
  1994 
  1995 * Configuration options are maintained within the theory or proof
  1996 context (with name and type bool/int/string), providing a very simple
  1997 interface to a poor-man's version of general context data.  Tools may
  1998 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1999 these values using Config.get etc.  Users may change options via an
  2000 associated attribute of the same name.  This form of context
  2001 declaration works particularly well with commands 'declare' or
  2002 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  2003 very easy to avoid global references, which would not observe Isar
  2004 toplevel undo/redo and fail to work with multithreading.
  2005 
  2006 Various global ML references of Pure and HOL have been turned into
  2007 configuration options:
  2008 
  2009   Unify.search_bound		unify_search_bound
  2010   Unify.trace_bound		unify_trace_bound
  2011   Unify.trace_simp		unify_trace_simp
  2012   Unify.trace_types		unify_trace_types
  2013   Simplifier.simp_depth_limit	simp_depth_limit
  2014   Blast.depth_limit		blast_depth_limit
  2015   DatatypeProp.dtK		datatype_distinctness_limit
  2016   fast_arith_neq_limit  	fast_arith_neq_limit
  2017   fast_arith_split_limit	fast_arith_split_limit
  2018 
  2019 * Named collections of theorems may be easily installed as context
  2020 data using the functor NamedThmsFun (see also
  2021 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  2022 attributes; there is also a toplevel print command.  This facility is
  2023 just a common case of general context data, which is the preferred way
  2024 for anything more complex than just a list of facts in canonical
  2025 order.
  2026 
  2027 * Isar: command 'declaration' augments a local theory by generic
  2028 declaration functions written in ML.  This enables arbitrary content
  2029 being added to the context, depending on a morphism that tells the
  2030 difference of the original declaration context wrt. the application
  2031 context encountered later on.
  2032 
  2033 * Isar: proper interfaces for simplification procedures.  Command
  2034 'simproc_setup' declares named simprocs (with match patterns, and body
  2035 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  2036 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  2037 
  2038 * Isar: an extra pair of brackets around attribute declarations
  2039 abbreviates a theorem reference involving an internal dummy fact,
  2040 which will be ignored later --- only the effect of the attribute on
  2041 the background context will persist.  This form of in-place
  2042 declarations is particularly useful with commands like 'declare' and
  2043 'using', for example ``have A using [[simproc a]] by simp''.
  2044 
  2045 * Isar: method "assumption" (and implicit closing of subproofs) now
  2046 takes simple non-atomic goal assumptions into account: after applying
  2047 an assumption as a rule the resulting subgoals are solved by atomic
  2048 assumption steps.  This is particularly useful to finish 'obtain'
  2049 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  2050 without referring to the original premise "!!x. P x ==> thesis" in the
  2051 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  2052 more permissive.
  2053 
  2054 * Isar: implicit use of prems from the Isar proof context is
  2055 considered a legacy feature.  Common applications like ``have A .''
  2056 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  2057 referencing facts explicitly here improves readability and
  2058 maintainability of proof texts.
  2059 
  2060 * Isar: improper proof element 'guess' is like 'obtain', but derives
  2061 the obtained context from the course of reasoning!  For example:
  2062 
  2063   assume "EX x y. A x & B y"   -- "any previous fact"
  2064   then guess x and y by clarify
  2065 
  2066 This technique is potentially adventurous, depending on the facts and
  2067 proof tools being involved here.
  2068 
  2069 * Isar: known facts from the proof context may be specified as literal
  2070 propositions, using ASCII back-quote syntax.  This works wherever
  2071 named facts used to be allowed so far, in proof commands, proof
  2072 methods, attributes etc.  Literal facts are retrieved from the context
  2073 according to unification of type and term parameters.  For example,
  2074 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  2075 theorems in the current context, then these are valid literal facts:
  2076 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  2077 
  2078 There is also a proof method "fact" which does the same composition
  2079 for explicit goal states, e.g. the following proof texts coincide with
  2080 certain special cases of literal facts:
  2081 
  2082   have "A" by fact                 ==  note `A`
  2083   have "A ==> B" by fact           ==  note `A ==> B`
  2084   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  2085   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  2086 
  2087 * Isar: ":" (colon) is no longer a symbolic identifier character in
  2088 outer syntax.  Thus symbolic identifiers may be used without
  2089 additional white space in declarations like this: ``assume *: A''.
  2090 
  2091 * Isar: 'print_facts' prints all local facts of the current context,
  2092 both named and unnamed ones.
  2093 
  2094 * Isar: 'def' now admits simultaneous definitions, e.g.:
  2095 
  2096   def x == "t" and y == "u"
  2097 
  2098 * Isar: added command 'unfolding', which is structurally similar to
  2099 'using', but affects both the goal state and facts by unfolding given
  2100 rewrite rules.  Thus many occurrences of the 'unfold' method or
  2101 'unfolded' attribute may be replaced by first-class proof text.
  2102 
  2103 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  2104 and command 'unfolding' now all support object-level equalities
  2105 (potentially conditional).  The underlying notion of rewrite rule is
  2106 analogous to the 'rule_format' attribute, but *not* that of the
  2107 Simplifier (which is usually more generous).
  2108 
  2109 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  2110 premises of a theorem by n. Useful in conjunction with drule.
  2111 
  2112 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  2113 method expression within a sandbox consisting of the first N
  2114 sub-goals, which need to exist.  For example, ``simp_all [3]''
  2115 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  2116 simplifies all new goals that emerge from applying rule foo to the
  2117 originally first one.
  2118 
  2119 * Isar: schematic goals are no longer restricted to higher-order
  2120 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  2121 expected.
  2122 
  2123 * Isar: the conclusion of a long theorem statement is now either
  2124 'shows' (a simultaneous conjunction, as before), or 'obtains'
  2125 (essentially a disjunction of cases with local parameters and
  2126 assumptions).  The latter allows to express general elimination rules
  2127 adequately; in this notation common elimination rules look like this:
  2128 
  2129   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  2130     assumes "EX x. P x"
  2131     obtains x where "P x"
  2132 
  2133   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  2134     assumes "A & B"
  2135     obtains A and B
  2136 
  2137   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  2138     assumes "A | B"
  2139     obtains
  2140       A
  2141     | B
  2142 
  2143 The subsequent classical rules even refer to the formal "thesis"
  2144 explicitly:
  2145 
  2146   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  2147     obtains "~ thesis"
  2148 
  2149   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  2150     obtains "thesis ==> something"
  2151 
  2152 The actual proof of an 'obtains' statement is analogous to that of the
  2153 Isar proof element 'obtain', only that there may be several cases.
  2154 Optional case names may be specified in parentheses; these will be
  2155 available both in the present proof and as annotations in the
  2156 resulting rule, for later use with the 'cases' method (cf. attribute
  2157 case_names).
  2158 
  2159 * Isar: the assumptions of a long theorem statement are available as
  2160 "assms" fact in the proof context.  This is more appropriate than the
  2161 (historical) "prems", which refers to all assumptions of the current
  2162 context, including those from the target locale, proof body etc.
  2163 
  2164 * Isar: 'print_statement' prints theorems from the current theory or
  2165 proof context in long statement form, according to the syntax of a
  2166 top-level lemma.
  2167 
  2168 * Isar: 'obtain' takes an optional case name for the local context
  2169 introduction rule (default "that").
  2170 
  2171 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2172 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2173 to occur.
  2174 
  2175 * Pure: syntax "CONST name" produces a fully internalized constant
  2176 according to the current context.  This is particularly useful for
  2177 syntax translations that should refer to internal constant
  2178 representations independently of name spaces.
  2179 
  2180 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2181 instead of "FOO ". This allows multiple binder declarations to coexist
  2182 in the same context.  INCOMPATIBILITY.
  2183 
  2184 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2185 primitive that also works in a locale context (both for constants and
  2186 fixed variables). Type declaration and internal syntactic representation
  2187 of given constants retrieved from the context. Likewise, the
  2188 'no_notation' command allows to remove given syntax annotations from the
  2189 current context.
  2190 
  2191 * Isar/locales: new derived specification elements 'axiomatization',
  2192 'definition', 'abbreviation', which support type-inference, admit
  2193 object-level specifications (equality, equivalence).  See also the
  2194 isar-ref manual.  Examples:
  2195 
  2196   axiomatization
  2197     eq  (infix "===" 50) where
  2198     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2199 
  2200   definition "f x y = x + y + 1"
  2201   definition g where "g x = f x x"
  2202 
  2203   abbreviation
  2204     neq  (infix "=!=" 50) where
  2205     "x =!= y == ~ (x === y)"
  2206 
  2207 These specifications may be also used in a locale context.  Then the
  2208 constants being introduced depend on certain fixed parameters, and the
  2209 constant name is qualified by the locale base name.  An internal
  2210 abbreviation takes care for convenient input and output, making the
  2211 parameters implicit and using the original short name.  See also
  2212 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2213 entities from a monomorphic theory.
  2214 
  2215 Presently, abbreviations are only available 'in' a target locale, but
  2216 not inherited by general import expressions.  Also note that
  2217 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2218 'translations' in common applications.  The "no_abbrevs" print mode
  2219 prevents folding of abbreviations in term output.
  2220 
  2221 Concrete syntax is attached to specified constants in internal form,
  2222 independently of name spaces.  The parse tree representation is
  2223 slightly different -- use 'notation' instead of raw 'syntax', and
  2224 'translations' with explicit "CONST" markup to accommodate this.
  2225 
  2226 * Pure/Isar: unified syntax for new-style specification mechanisms
  2227 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2228 full type inference and dummy patterns ("_").  For example:
  2229 
  2230   definition "K x _ = x"
  2231 
  2232   inductive conj for A B
  2233   where "A ==> B ==> conj A B"
  2234 
  2235 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2236 the current context.  Print mode "no_abbrevs" prevents inversion of
  2237 abbreviations on output.
  2238 
  2239 * Isar/locales: improved parameter handling: use of locales "var" and
  2240 "struct" no longer necessary; - parameter renamings are no longer
  2241 required to be injective.  For example, this allows to define
  2242 endomorphisms as locale endom = homom mult mult h.
  2243 
  2244 * Isar/locales: changed the way locales with predicates are defined.
  2245 Instead of accumulating the specification, the imported expression is
  2246 now an interpretation.  INCOMPATIBILITY: different normal form of
  2247 locale expressions.  In particular, in interpretations of locales with
  2248 predicates, goals repesenting already interpreted fragments are not
  2249 removed automatically.  Use methods `intro_locales' and
  2250 `unfold_locales'; see below.
  2251 
  2252 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2253 provide backward reasoning on locales predicates.  The methods are
  2254 aware of interpretations and discharge corresponding goals.
  2255 `intro_locales' is less aggressive then `unfold_locales' and does not
  2256 unfold predicates to assumptions.
  2257 
  2258 * Isar/locales: the order in which locale fragments are accumulated
  2259 has changed.  This enables to override declarations from fragments due
  2260 to interpretations -- for example, unwanted simp rules.
  2261 
  2262 * Isar/locales: interpretation in theories and proof contexts has been
  2263 extended.  One may now specify (and prove) equations, which are
  2264 unfolded in interpreted theorems.  This is useful for replacing
  2265 defined concepts (constants depending on locale parameters) by
  2266 concepts already existing in the target context.  Example:
  2267 
  2268   interpretation partial_order ["op <= :: [int, int] => bool"]
  2269     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2270 
  2271 Typically, the constant `partial_order.less' is created by a
  2272 definition specification element in the context of locale
  2273 partial_order.
  2274 
  2275 * Method "induct": improved internal context management to support
  2276 local fixes and defines on-the-fly. Thus explicit meta-level
  2277 connectives !!  and ==> are rarely required anymore in inductive goals
  2278 (using object-logic connectives for this purpose has been long
  2279 obsolete anyway). Common proof patterns are explained in
  2280 src/HOL/Induct/Common_Patterns.thy, see also
  2281 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2282 examples.
  2283 
  2284 * Method "induct": improved handling of simultaneous goals. Instead of
  2285 introducing object-level conjunction, the statement is now split into
  2286 several conclusions, while the corresponding symbolic cases are nested
  2287 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2288 see src/HOL/Induct/Common_Patterns.thy, for example.
  2289 
  2290 * Method "induct": mutual induction rules are now specified as a list
  2291 of rule sharing the same induction cases. HOL packages usually provide
  2292 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2293 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2294 mutual induction rules differently, i.e. like this:
  2295 
  2296   (induct rule: foo_bar.inducts)
  2297   (induct set: foo bar)
  2298   (induct pred: foo bar)
  2299   (induct type: foo bar)
  2300 
  2301 The ML function ProjectRule.projections turns old-style rules into the
  2302 new format.
  2303 
  2304 * Method "coinduct": dual of induction, see
  2305 src/HOL/Library/Coinductive_List.thy for various examples.
  2306 
  2307 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2308 considered a legacy feature.
  2309 
  2310 * Attribute "symmetric" produces result with standardized schematic
  2311 variables (index 0).  Potential INCOMPATIBILITY.
  2312 
  2313 * Simplifier: by default the simplifier trace only shows top level
  2314 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2315 default. Thus there is less danger of being flooded by the trace. The
  2316 trace indicates where parts have been suppressed.
  2317   
  2318 * Provers/classical: removed obsolete classical version of elim_format
  2319 attribute; classical elim/dest rules are now treated uniformly when
  2320 manipulating the claset.
  2321 
  2322 * Provers/classical: stricter checks to ensure that supplied intro,
  2323 dest and elim rules are well-formed; dest and elim rules must have at
  2324 least one premise.
  2325 
  2326 * Provers/classical: attributes dest/elim/intro take an optional
  2327 weight argument for the rule (just as the Pure versions).  Weights are
  2328 ignored by automated tools, but determine the search order of single
  2329 rule steps.
  2330 
  2331 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2332 where the body does not mention the bound variable.  Note that dummy
  2333 patterns implicitly depend on their context of bounds, which makes
  2334 "{_. _}" match any set comprehension as expected.  Potential
  2335 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2336 constant "_idtdummy" in the binding position.
  2337 
  2338 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2339 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2340 for example "A -> B" => "Pi A (%_. B)".
  2341 
  2342 * Pure: 'class_deps' command visualizes the subclass relation, using
  2343 the graph browser tool.
  2344 
  2345 * Pure: 'print_theory' now suppresses certain internal declarations by
  2346 default; use '!' option for full details.
  2347 
  2348 
  2349 *** HOL ***
  2350 
  2351 * Method "metis" proves goals by applying the Metis general-purpose
  2352 resolution prover (see also http://gilith.com/software/metis/).
  2353 Examples are in the directory MetisExamples.  WARNING: the
  2354 Isabelle/HOL-Metis integration does not yet work properly with
  2355 multi-threading.
  2356   
  2357 * Command 'sledgehammer' invokes external automatic theorem provers as
  2358 background processes.  It generates calls to the "metis" method if
  2359 successful. These can be pasted into the proof.  Users do not have to
  2360 wait for the automatic provers to return.  WARNING: does not really
  2361 work with multi-threading.
  2362 
  2363 * New "auto_quickcheck" feature tests outermost goal statements for
  2364 potential counter-examples.  Controlled by ML references
  2365 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2366 5000 milliseconds).  Fails silently if statements is outside of
  2367 executable fragment, or any other codgenerator problem occurs.
  2368 
  2369 * New constant "undefined" with axiom "undefined x = undefined".
  2370 
  2371 * Added class "HOL.eq", allowing for code generation with polymorphic
  2372 equality.
  2373 
  2374 * Some renaming of class constants due to canonical name prefixing in
  2375 the new 'class' package:
  2376 
  2377     HOL.abs ~> HOL.abs_class.abs
  2378     HOL.divide ~> HOL.divide_class.divide
  2379     0 ~> HOL.zero_class.zero
  2380     1 ~> HOL.one_class.one
  2381     op + ~> HOL.plus_class.plus
  2382     op - ~> HOL.minus_class.minus
  2383     uminus ~> HOL.minus_class.uminus
  2384     op * ~> HOL.times_class.times
  2385     op < ~> HOL.ord_class.less
  2386     op <= > HOL.ord_class.less_eq
  2387     Nat.power ~> Power.power_class.power
  2388     Nat.size ~> Nat.size_class.size
  2389     Numeral.number_of ~> Numeral.number_class.number_of
  2390     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2391     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2392     Orderings.min ~> Orderings.ord_class.min
  2393     Orderings.max ~> Orderings.ord_class.max
  2394     Divides.op div ~> Divides.div_class.div
  2395     Divides.op mod ~> Divides.div_class.mod
  2396     Divides.op dvd ~> Divides.div_class.dvd
  2397 
  2398 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2399 
  2400 a) User-defined constants using any of the names "plus", "minus",
  2401 "times", "less" or "less_eq". The standard syntax translations for
  2402 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2403 names.
  2404 
  2405 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2406 INCOMPATIBILITY: use more specific names.
  2407 
  2408 c) Permutative equations (e.g. "a + b = b + a")
  2409 Since the change of names also changes the order of terms, permutative
  2410 rewrite rules may get applied in a different order. Experience shows
  2411 that this is rarely the case (only two adaptions in the whole Isabelle
  2412 distribution).  INCOMPATIBILITY: rewrite proofs
  2413 
  2414 d) ML code directly refering to constant names
  2415 This in general only affects hand-written proof tactics, simprocs and
  2416 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2417 Consider using @{const_name} antiquotation.
  2418 
  2419 * New class "default" with associated constant "default".
  2420 
  2421 * Function "sgn" is now overloaded and available on int, real, complex
  2422 (and other numeric types), using class "sgn".  Two possible defs of
  2423 sgn are given as equational assumptions in the classes sgn_if and
  2424 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2425 INCOMPATIBILITY.
  2426 
  2427 * Locale "partial_order" now unified with class "order" (cf. theory
  2428 Orderings), added parameter "less".  INCOMPATIBILITY.
  2429 
  2430 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2431 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2432 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2433 
  2434 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2435 changed order of proof goals in instance proofs.
  2436 
  2437 * The transitivity reasoner for partial and linear orders is set up
  2438 for classes "order" and "linorder".  Instances of the reasoner are available
  2439 in all contexts importing or interpreting the corresponding locales.
  2440 Method "order" invokes the reasoner separately; the reasoner
  2441 is also integrated with the Simplifier as a solver.  Diagnostic
  2442 command 'print_orders' shows the available instances of the reasoner
  2443 in the current context.
  2444 
  2445 * Localized monotonicity predicate in theory "Orderings"; integrated
  2446 lemmas max_of_mono and min_of_mono with this predicate.
  2447 INCOMPATIBILITY.
  2448 
  2449 * Formulation of theorem "dense" changed slightly due to integration
  2450 with new class dense_linear_order.
  2451 
  2452 * Uniform lattice theory development in HOL.
  2453 
  2454     constants "meet" and "join" now named "inf" and "sup"
  2455     constant "Meet" now named "Inf"
  2456 
  2457     classes "meet_semilorder" and "join_semilorder" now named
  2458       "lower_semilattice" and "upper_semilattice"
  2459     class "lorder" now named "lattice"
  2460     class "comp_lat" now named "complete_lattice"
  2461 
  2462     Instantiation of lattice classes allows explicit definitions
  2463     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2464 
  2465   INCOMPATIBILITY.  Theorem renames:
  2466 
  2467     meet_left_le            ~> inf_le1
  2468     meet_right_le           ~> inf_le2
  2469     join_left_le            ~> sup_ge1
  2470     join_right_le           ~> sup_ge2
  2471     meet_join_le            ~> inf_sup_ord
  2472     le_meetI                ~> le_infI
  2473     join_leI                ~> le_supI
  2474     le_meet                 ~> le_inf_iff
  2475     le_join                 ~> ge_sup_conv
  2476     meet_idempotent         ~> inf_idem
  2477     join_idempotent         ~> sup_idem
  2478     meet_comm               ~> inf_commute
  2479     join_comm               ~> sup_commute
  2480     meet_leI1               ~> le_infI1
  2481     meet_leI2               ~> le_infI2
  2482     le_joinI1               ~> le_supI1
  2483     le_joinI2               ~> le_supI2
  2484     meet_assoc              ~> inf_assoc
  2485     join_assoc              ~> sup_assoc
  2486     meet_left_comm          ~> inf_left_commute
  2487     meet_left_idempotent    ~> inf_left_idem
  2488     join_left_comm          ~> sup_left_commute
  2489     join_left_idempotent    ~> sup_left_idem
  2490     meet_aci                ~> inf_aci
  2491     join_aci                ~> sup_aci
  2492     le_def_meet             ~> le_iff_inf
  2493     le_def_join             ~> le_iff_sup
  2494     join_absorp2            ~> sup_absorb2
  2495     join_absorp1            ~> sup_absorb1
  2496     meet_absorp1            ~> inf_absorb1
  2497     meet_absorp2            ~> inf_absorb2
  2498     meet_join_absorp        ~> inf_sup_absorb
  2499     join_meet_absorp        ~> sup_inf_absorb
  2500     distrib_join_le         ~> distrib_sup_le
  2501     distrib_meet_le         ~> distrib_inf_le
  2502 
  2503     add_meet_distrib_left   ~> add_inf_distrib_left
  2504     add_join_distrib_left   ~> add_sup_distrib_left
  2505     is_join_neg_meet        ~> is_join_neg_inf
  2506     is_meet_neg_join        ~> is_meet_neg_sup
  2507     add_meet_distrib_right  ~> add_inf_distrib_right
  2508     add_join_distrib_right  ~> add_sup_distrib_right
  2509     add_meet_join_distribs  ~> add_sup_inf_distribs
  2510     join_eq_neg_meet        ~> sup_eq_neg_inf
  2511     meet_eq_neg_join        ~> inf_eq_neg_sup
  2512     add_eq_meet_join        ~> add_eq_inf_sup
  2513     meet_0_imp_0            ~> inf_0_imp_0
  2514     join_0_imp_0            ~> sup_0_imp_0
  2515     meet_0_eq_0             ~> inf_0_eq_0
  2516     join_0_eq_0             ~> sup_0_eq_0
  2517     neg_meet_eq_join        ~> neg_inf_eq_sup
  2518     neg_join_eq_meet        ~> neg_sup_eq_inf
  2519     join_eq_if              ~> sup_eq_if
  2520 
  2521     mono_meet               ~> mono_inf
  2522     mono_join               ~> mono_sup
  2523     meet_bool_eq            ~> inf_bool_eq
  2524     join_bool_eq            ~> sup_bool_eq
  2525     meet_fun_eq             ~> inf_fun_eq
  2526     join_fun_eq             ~> sup_fun_eq
  2527     meet_set_eq             ~> inf_set_eq
  2528     join_set_eq             ~> sup_set_eq
  2529     meet1_iff               ~> inf1_iff
  2530     meet2_iff               ~> inf2_iff
  2531     meet1I                  ~> inf1I
  2532     meet2I                  ~> inf2I
  2533     meet1D1                 ~> inf1D1
  2534     meet2D1                 ~> inf2D1
  2535     meet1D2                 ~> inf1D2
  2536     meet2D2                 ~> inf2D2
  2537     meet1E                  ~> inf1E
  2538     meet2E                  ~> inf2E
  2539     join1_iff               ~> sup1_iff
  2540     join2_iff               ~> sup2_iff
  2541     join1I1                 ~> sup1I1
  2542     join2I1                 ~> sup2I1
  2543     join1I1                 ~> sup1I1
  2544     join2I2                 ~> sup1I2
  2545     join1CI                 ~> sup1CI
  2546     join2CI                 ~> sup2CI
  2547     join1E                  ~> sup1E
  2548     join2E                  ~> sup2E
  2549 
  2550     is_meet_Meet            ~> is_meet_Inf
  2551     Meet_bool_def           ~> Inf_bool_def
  2552     Meet_fun_def            ~> Inf_fun_def
  2553     Meet_greatest           ~> Inf_greatest
  2554     Meet_lower              ~> Inf_lower
  2555     Meet_set_def            ~> Inf_set_def
  2556 
  2557     Sup_def                 ~> Sup_Inf
  2558     Sup_bool_eq             ~> Sup_bool_def
  2559     Sup_fun_eq              ~> Sup_fun_def
  2560     Sup_set_eq              ~> Sup_set_def
  2561 
  2562     listsp_meetI            ~> listsp_infI
  2563     listsp_meet_eq          ~> listsp_inf_eq
  2564 
  2565     meet_min                ~> inf_min
  2566     join_max                ~> sup_max
  2567 
  2568 * Added syntactic class "size"; overloaded constant "size" now has
  2569 type "'a::size ==> bool"
  2570 
  2571 * Internal reorganisation of `size' of datatypes: size theorems
  2572 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2573 simplification rules by default!); theorems "prod.size" now named
  2574 "*.size".
  2575 
  2576 * Class "div" now inherits from class "times" rather than "type".
  2577 INCOMPATIBILITY.
  2578 
  2579 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2580 Linorder etc.  have disappeared; operations defined in terms of
  2581 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2582 
  2583 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2584 
  2585 * HOL-Word: New extensive library and type for generic, fixed size
  2586 machine words, with arithemtic, bit-wise, shifting and rotating
  2587 operations, reflection into int, nat, and bool lists, automation for
  2588 linear arithmetic (by automatic reflection into nat or int), including
  2589 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2590 arithmetic type classes, supporting automatic simplification of
  2591 numerals on all operations.
  2592 
  2593 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2594 
  2595 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2596 
  2597 * Code generator library theories:
  2598   - Code_Integer represents HOL integers by big integer literals in target
  2599     languages.
  2600   - Code_Char represents HOL characters by character literals in target
  2601     languages.
  2602   - Code_Char_chr like Code_Char, but also offers treatment of character
  2603     codes; includes Code_Integer.
  2604   - Executable_Set allows to generate code for finite sets using lists.
  2605   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2606     denominator).
  2607   - Executable_Real implements a subset of real numbers, namly those
  2608     representable by rational numbers.
  2609   - Efficient_Nat implements natural numbers by integers, which in general will
  2610     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2611     includes Code_Integer.
  2612   - Code_Index provides an additional datatype index which is mapped to
  2613     target-language built-in integers.
  2614   - Code_Message provides an additional datatype message_string which is isomorphic to
  2615     strings; messages are mapped to target-language strings.
  2616 
  2617 * New package for inductive predicates
  2618 
  2619   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2620 
  2621     inductive
  2622       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2623       for z_1 :: U_1 and ... and z_n :: U_m
  2624     where
  2625       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2626     | ...
  2627 
  2628   with full support for type-inference, rather than
  2629 
  2630     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2631 
  2632     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2633     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2634 
  2635     inductive "s z_1 ... z_m"
  2636     intros
  2637       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2638       ...
  2639 
  2640   For backward compatibility, there is a wrapper allowing inductive
  2641   sets to be defined with the new package via
  2642 
  2643     inductive_set
  2644       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2645       for z_1 :: U_1 and ... and z_n :: U_m
  2646     where
  2647       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2648     | ...
  2649 
  2650   or
  2651 
  2652     inductive_set
  2653       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2654       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2655       for z_1 :: U_1 and ... and z_n :: U_m
  2656     where
  2657       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2658     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2659     | ...
  2660 
  2661   if the additional syntax "p ..." is required.
  2662 
  2663   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2664   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2665 
  2666   INCOMPATIBILITIES:
  2667 
  2668   - Since declaration and definition of inductive sets or predicates
  2669     is no longer separated, abbreviations involving the newly
  2670     introduced sets or predicates must be specified together with the
  2671     introduction rules after the 'where' keyword (see above), rather
  2672     than before the actual inductive definition.
  2673 
  2674   - The variables in induction and elimination rules are now
  2675     quantified in the order of their occurrence in the introduction
  2676     rules, rather than in alphabetical order. Since this may break
  2677     some proofs, these proofs either have to be repaired, e.g. by
  2678     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2679     statements of the form
  2680 
  2681       case (rule_i a_i_1 ... a_i_{k_i})
  2682 
  2683     or the old order of quantification has to be restored by explicitly adding
  2684     meta-level quantifiers in the introduction rules, i.e.
  2685 
  2686       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2687 
  2688   - The format of the elimination rules is now
  2689 
  2690       p z_1 ... z_m x_1 ... x_n ==>
  2691         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2692         ==> ... ==> P
  2693 
  2694     for predicates and
  2695 
  2696       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2697         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2698         ==> ... ==> P
  2699 
  2700     for sets rather than
  2701 
  2702       x : s z_1 ... z_m ==>
  2703         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2704         ==> ... ==> P
  2705 
  2706     This may require terms in goals to be expanded to n-tuples
  2707     (e.g. using case_tac or simplification with the split_paired_all
  2708     rule) before the above elimination rule is applicable.
  2709 
  2710   - The elimination or case analysis rules for (mutually) inductive
  2711     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2712     list of rules "p_1_..._p_k.elims" is no longer available.
  2713 
  2714 * New package "function"/"fun" for general recursive functions,
  2715 supporting mutual and nested recursion, definitions in local contexts,
  2716 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2717 for small examples, and the separate tutorial on the function
  2718 package. The old recdef "package" is still available as before, but
  2719 users are encouraged to use the new package.
  2720 
  2721 * Method "lexicographic_order" automatically synthesizes termination
  2722 relations as lexicographic combinations of size measures. 
  2723 
  2724 * Case-expressions allow arbitrary constructor-patterns (including
  2725 "_") and take their order into account, like in functional
  2726 programming.  Internally, this is translated into nested
  2727 case-expressions; missing cases are added and mapped to the predefined
  2728 constant "undefined". In complicated cases printing may no longer show
  2729 the original input but the internal form. Lambda-abstractions allow
  2730 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2731 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2732 variable.
  2733 
  2734 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2735 is an abbreviation for "of_nat :: nat => int". The simplification
  2736 rules for "of_nat" have been changed to work like "int" did
  2737 previously.  Potential INCOMPATIBILITY:
  2738   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2739   - of_nat_diff and of_nat_mult are no longer default simp rules
  2740 
  2741 * Method "algebra" solves polynomial equations over (semi)rings using
  2742 Groebner bases. The (semi)ring structure is defined by locales and the
  2743 tool setup depends on that generic context. Installing the method for
  2744 a specific type involves instantiating the locale and possibly adding
  2745 declarations for computation on the coefficients.  The method is
  2746 already instantiated for natural numbers and for the axiomatic class
  2747 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2748 CALCULEMUS 2007 for the general principles underlying this
  2749 architecture of context-aware proof-tools.
  2750 
  2751 * Method "ferrack" implements quantifier elimination over
  2752 special-purpose dense linear orders using locales (analogous to
  2753 "algebra"). The method is already installed for class
  2754 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2755 rat, etc.
  2756 
  2757 * Former constant "List.op @" now named "List.append".  Use ML
  2758 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2759 circumvent possible incompatibilities when working on ML level.
  2760 
  2761 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2762 
  2763 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2764 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2765 
  2766 * New syntax for Haskell-like list comprehension (input only), eg.
  2767 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2768 
  2769 * The special syntax for function "filter" has changed from [x :
  2770 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2771 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2772 
  2773 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2774 defined on nat only, as an abbreviation for [a..<Suc b]
  2775 INCOMPATIBILITY.
  2776 
  2777 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2778 
  2779 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2780 
  2781 * New lemma collection field_simps (an extension of ring_simps) for
  2782 manipulating (in)equations involving division. Multiplies with all
  2783 denominators that can be proved to be non-zero (in equations) or
  2784 positive/negative (in inequations).
  2785 
  2786 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2787 have been improved and renamed to ring_simps, group_simps and
  2788 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2789 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2790 
  2791 * Theory Library/Commutative_Ring: switched from recdef to function
  2792 package; constants add, mul, pow now curried.  Infix syntax for
  2793 algebraic operations.
  2794 
  2795 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2796 INCOMPATIBILITY.
  2797 
  2798 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2799 INCOMPATIBILITY.
  2800 
  2801 * HOL/records: generalised field-update to take a function on the
  2802 field rather than the new value: r(|A := x|) is translated to A_update
  2803 (K x) r The K-combinator that is internally used is called K_record.
  2804 INCOMPATIBILITY: Usage of the plain update functions has to be
  2805 adapted.
  2806  
  2807 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2808 * x = 0, which are required for a semiring.  Richer structures do not
  2809 inherit from semiring_0 anymore, because this property is a theorem
  2810 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2811 there is more to prove, but this is mostly trivial.
  2812 
  2813 * Class "recpower" is generalized to arbitrary monoids, not just
  2814 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2815 commutativity or semiring properties additionally.
  2816 
  2817 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2818 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2819 better use 'abbreviation'.
  2820 
  2821 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2822 
  2823 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2824 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2825 significant changes for setting up numeral syntax for types:
  2826   - New constants Numeral.pred and Numeral.succ instead
  2827       of former Numeral.bin_pred and Numeral.bin_succ.
  2828   - Use integer operations instead of bin_add, bin_mult and so on.
  2829   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2830   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2831 
  2832 See src/HOL/Integ/IntArith.thy for an example setup.
  2833 
  2834 * Command 'normal_form' computes the normal form of a term that may
  2835 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2836 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2837 heavy-duty computations because the functions are compiled to ML
  2838 first.  Correspondingly, a method "normalization" is provided.  See
  2839 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2840 
  2841 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2842 25 like -->); output depends on the "iff" print_mode, the default is
  2843 "A = B" (with priority 50).
  2844 
  2845 * Relations less (<) and less_eq (<=) are also available on type bool.
  2846 Modified syntax to disallow nesting without explicit parentheses,
  2847 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2848 INCOMPATIBILITY.
  2849 
  2850 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2851 
  2852 * Relation composition operator "op O" now has precedence 75 and binds
  2853 stronger than union and intersection. INCOMPATIBILITY.
  2854 
  2855 * The old set interval syntax "{m..n(}" (and relatives) has been
  2856 removed.  Use "{m..<n}" (and relatives) instead.
  2857 
  2858 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2859 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2860 ``declare [[simproc del: neq]]''.
  2861 
  2862 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2863 True/False.
  2864 
  2865 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2866 
  2867 * Theorem setsum_mult renamed to setsum_right_distrib.
  2868 
  2869 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2870 ``rule'' method.
  2871 
  2872 * Reimplemented methods "sat" and "satx", with several improvements:
  2873 goals no longer need to be stated as "<prems> ==> False", equivalences
  2874 (i.e. "=" on type bool) are handled, variable names of the form
  2875 "lit_<n>" are no longer reserved, significant speedup.
  2876 
  2877 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2878 zChaff is still supported as well.
  2879 
  2880 * 'inductive' and 'datatype': provide projections of mutual rules,
  2881 bundled as foo_bar.inducts;
  2882 
  2883 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2884 Library.
  2885 
  2886 * Library: moved theory Accessible_Part to main HOL.
  2887 
  2888 * Library: added theory Coinductive_List of potentially infinite lists
  2889 as greatest fixed-point.
  2890 
  2891 * Library: added theory AssocList which implements (finite) maps as
  2892 association lists.
  2893 
  2894 * Method "evaluation" solves goals (i.e. a boolean expression)
  2895 efficiently by compiling it to ML.  The goal is "proved" (via an
  2896 oracle) if it evaluates to True.
  2897 
  2898 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2899 also when invoked by the simplifier.  This results in the Simplifier
  2900 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2901 Configuration option fast_arith_split_limit=0 recovers the old
  2902 behavior.
  2903 
  2904 * Support for hex (0x20) and binary (0b1001) numerals.
  2905 
  2906 * New method: reify eqs (t), where eqs are equations for an
  2907 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2908 parameter, computes a term s::'b and a list xs::'a list and proves the
  2909 theorem I xs s = t. This is also known as reification or quoting. The
  2910 resulting theorem is applied to the subgoal to substitute t with I xs
  2911 s.  If t is omitted, the subgoal itself is reified.
  2912 
  2913 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2914 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2915 where f is supposed to be a computable function (in the sense of code
  2916 generattion). The method uses reify to compute s and xs as above then
  2917 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2918 r and finally gets the theorem t = r, which is again applied to the
  2919 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2920 
  2921 * Reflection: Automatic reification now handels binding, an example is
  2922 available in src/HOL/ex/ReflectionEx.thy
  2923 
  2924 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2925 command 'statespace' that is similar to 'record', but introduces an
  2926 abstract specification based on the locale infrastructure instead of
  2927 HOL types.  This leads to extra flexibility in composing state spaces,
  2928 in particular multiple inheritance and renaming of components.
  2929 
  2930 
  2931 *** HOL-Complex ***
  2932 
  2933 * Hyperreal: Functions root and sqrt are now defined on negative real
  2934 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2935 Nonnegativity side conditions have been removed from many lemmas, so
  2936 that more subgoals may now be solved by simplification; potential
  2937 INCOMPATIBILITY.
  2938 
  2939 * Real: new type classes formalize real normed vector spaces and
  2940 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2941 and norm :: 'a => real.
  2942 
  2943 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2944 reals into other types. The overloaded constant Reals :: 'a set is now
  2945 defined as range of_real; potential INCOMPATIBILITY.
  2946 
  2947 * Real: proper support for ML code generation, including 'quickcheck'.
  2948 Reals are implemented as arbitrary precision rationals.
  2949 
  2950 * Hyperreal: Several constants that previously worked only for the
  2951 reals have been generalized, so they now work over arbitrary vector
  2952 spaces. Type annotations may need to be added in some cases; potential
  2953 INCOMPATIBILITY.
  2954 
  2955   Infinitesimal  :: ('a::real_normed_vector) star set
  2956   HFinite        :: ('a::real_normed_vector) star set
  2957   HInfinite      :: ('a::real_normed_vector) star set
  2958   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2959   monad          :: ('a::real_normed_vector) star => 'a star set
  2960   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2961   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2962   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2963   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2964   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2965   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2966   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2967   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2968   sgn            :: 'a::real_normed_vector => 'a
  2969   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2970 
  2971 * Complex: Some complex-specific constants are now abbreviations for
  2972 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2973 hnorm.  Other constants have been entirely removed in favor of the
  2974 polymorphic versions (INCOMPATIBILITY):
  2975 
  2976   approx        <-- capprox
  2977   HFinite       <-- CFinite
  2978   HInfinite     <-- CInfinite
  2979   Infinitesimal <-- CInfinitesimal
  2980   monad         <-- cmonad
  2981   galaxy        <-- cgalaxy
  2982   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2983   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2984   (ns)deriv     <-- (ns)cderiv
  2985 
  2986 
  2987 *** HOL-Algebra ***
  2988 
  2989 * Formalisation of ideals and the quotient construction over rings.
  2990 
  2991 * Order and lattice theory no longer based on records.
  2992 INCOMPATIBILITY.
  2993 
  2994 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2995 greatest_closed.  INCOMPATIBILITY.
  2996 
  2997 * Method algebra is now set up via an attribute.  For examples see
  2998 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2999 of algebraic structures.
  3000 
  3001 * Renamed theory CRing to Ring.
  3002 
  3003 
  3004 *** HOL-Nominal ***
  3005 
  3006 * Substantial, yet incomplete support for nominal datatypes (binding
  3007 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  3008 src/HOL/Nominal/Examples.  Prospective users should consult
  3009 http://isabelle.in.tum.de/nominal/
  3010 
  3011 
  3012 *** ML ***
  3013 
  3014 * ML basics: just one true type int, which coincides with IntInf.int
  3015 (even on SML/NJ).
  3016 
  3017 * ML within Isar: antiquotations allow to embed statically-checked
  3018 formal entities in the source, referring to the context available at
  3019 compile-time.  For example:
  3020 
  3021 ML {* @{sort "{zero,one}"} *}
  3022 ML {* @{typ "'a => 'b"} *}
  3023 ML {* @{term "%x. x"} *}
  3024 ML {* @{prop "x == y"} *}
  3025 ML {* @{ctyp "'a => 'b"} *}
  3026 ML {* @{cterm "%x. x"} *}
  3027 ML {* @{cprop "x == y"} *}
  3028 ML {* @{thm asm_rl} *}
  3029 ML {* @{thms asm_rl} *}
  3030 ML {* @{type_name c} *}
  3031 ML {* @{type_syntax c} *}
  3032 ML {* @{const_name c} *}
  3033 ML {* @{const_syntax c} *}
  3034 ML {* @{context} *}
  3035 ML {* @{theory} *}
  3036 ML {* @{theory Pure} *}
  3037 ML {* @{theory_ref} *}
  3038 ML {* @{theory_ref Pure} *}
  3039 ML {* @{simpset} *}
  3040 ML {* @{claset} *}
  3041 ML {* @{clasimpset} *}
  3042 
  3043 The same works for sources being ``used'' within an Isar context.
  3044 
  3045 * ML in Isar: improved error reporting; extra verbosity with
  3046 ML_Context.trace enabled.
  3047 
  3048 * Pure/General/table.ML: the join operations now works via exceptions
  3049 DUP/SAME instead of type option. This is simpler in simple cases, and
  3050 admits slightly more efficient complex applications.
  3051 
  3052 * Pure: 'advanced' translation functions (parse_translation etc.) now
  3053 use Context.generic instead of just theory.
  3054 
  3055 * Pure: datatype Context.generic joins theory/Proof.context and
  3056 provides some facilities for code that works in either kind of
  3057 context, notably GenericDataFun for uniform theory and proof data.
  3058 
  3059 * Pure: simplified internal attribute type, which is now always
  3060 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  3061 local (Proof.context) attributes have been discontinued, while
  3062 minimizing code duplication. Thm.rule_attribute and
  3063 Thm.declaration_attribute build canonical attributes; see also structure
  3064 Context for further operations on Context.generic, notably
  3065 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  3066 declarations and definitions.
  3067 
  3068 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  3069 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  3070 init only required for impure data. INCOMPATIBILITY: empty really need
  3071 to be empty (no dependencies on theory content!)
  3072 
  3073 * Pure/kernel: consts certification ignores sort constraints given in
  3074 signature declarations. (This information is not relevant to the
  3075 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  3076 potential INCOMPATIBILITY.
  3077 
  3078 * Pure: axiomatic type classes are now purely definitional, with
  3079 explicit proofs of class axioms and super class relations performed
  3080 internally. See Pure/axclass.ML for the main internal interfaces --
  3081 notably AxClass.define_class supercedes AxClass.add_axclass, and
  3082 AxClass.axiomatize_class/classrel/arity supersede
  3083 Sign.add_classes/classrel/arities.
  3084 
  3085 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  3086 global/local versions on theory vs. Proof.context have been
  3087 discontinued; Attrib.syntax and Method.syntax have been adapted
  3088 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  3089 attributes, methods, etc.
  3090 
  3091 * Pure: several functions of signature "... -> theory -> theory * ..."
  3092 have been reoriented to "... -> theory -> ... * theory" in order to
  3093 allow natural usage in combination with the ||>, ||>>, |-> and
  3094 fold_map combinators.
  3095 
  3096 * Pure: official theorem names (closed derivations) and additional
  3097 comments (tags) are now strictly separate.  Name hints -- which are
  3098 maintained as tags -- may be attached any time without affecting the
  3099 derivation.
  3100 
  3101 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  3102 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  3103 achieve the old behaviour.
  3104 
  3105 * Pure: the "Goal" constant is now called "prop", supporting a
  3106 slightly more general idea of ``protecting'' meta-level rule
  3107 statements.
  3108 
  3109 * Pure: Logic.(un)varify only works in a global context, which is now
  3110 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  3111 Logic.legacy_(un)varify as temporary workaround.
  3112 
  3113 * Pure: structure Name provides scalable operations for generating
  3114 internal variable names, notably Name.variants etc.  This replaces
  3115 some popular functions from term.ML:
  3116 
  3117   Term.variant		->  Name.variant
  3118   Term.variantlist	->  Name.variant_list
  3119   Term.invent_names	->  Name.invent_list
  3120 
  3121 Note that low-level renaming rarely occurs in new code -- operations
  3122 from structure Variable are used instead (see below).
  3123 
  3124 * Pure: structure Variable provides fundamental operations for proper
  3125 treatment of fixed/schematic variables in a context.  For example,
  3126 Variable.import introduces fixes for schematics of given facts and
  3127 Variable.export reverses the effect (up to renaming) -- this replaces
  3128 various freeze_thaw operations.
  3129 
  3130 * Pure: structure Goal provides simple interfaces for
  3131 init/conclude/finish and tactical prove operations (replacing former
  3132 Tactic.prove).  Goal.prove is the canonical way to prove results
  3133 within a given context; Goal.prove_global is a degraded version for
  3134 theory level goals, including a global Drule.standard.  Note that
  3135 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  3136 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  3137 in a locale context).
  3138 
  3139 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  3140 and type checking (Syntax.check_term etc.), with common combinations
  3141 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  3142 which are considered legacy and await removal.
  3143 
  3144 * Pure/Syntax: generic interfaces for type unchecking
  3145 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  3146 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  3147 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  3148 available for convenience, but refer to the very same operations using
  3149 a mere theory instead of a full context.
  3150 
  3151 * Isar: simplified treatment of user-level errors, using exception
  3152 ERROR of string uniformly.  Function error now merely raises ERROR,
  3153 without any side effect on output channels.  The Isar toplevel takes
  3154 care of proper display of ERROR exceptions.  ML code may use plain
  3155 handle/can/try; cat_error may be used to concatenate errors like this:
  3156 
  3157   ... handle ERROR msg => cat_error msg "..."
  3158 
  3159 Toplevel ML code (run directly or through the Isar toplevel) may be
  3160 embedded into the Isar toplevel with exception display/debug like
  3161 this:
  3162 
  3163   Isar.toplevel (fn () => ...)
  3164 
  3165 INCOMPATIBILITY, removed special transform_error facilities, removed
  3166 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3167 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3168 -- use plain ERROR instead.
  3169 
  3170 * Isar: theory setup now has type (theory -> theory), instead of a
  3171 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3172 
  3173 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3174 ProofContext.debug/verbose flags.
  3175 
  3176 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3177 theory before entering a proof state.  Transactions now always see a
  3178 quasi-functional intermediate checkpoint, both in interactive and
  3179 batch mode.
  3180 
  3181 * Isar: simplified interfaces for outer syntax.  Renamed
  3182 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3183 OuterSyntax.add_parsers -- this functionality is now included in
  3184 OuterSyntax.command etc.  INCOMPATIBILITY.
  3185 
  3186 * Simplifier: the simpset of a running simplification process now
  3187 contains a proof context (cf. Simplifier.the_context), which is the
  3188 very context that the initial simpset has been retrieved from (by
  3189 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3190 (solver, looper etc.) may depend on arbitrary proof data.
  3191 
  3192 * Simplifier.inherit_context inherits the proof context (plus the
  3193 local bounds) of the current simplification process; any simproc
  3194 etc. that calls the Simplifier recursively should do this!  Removed
  3195 former Simplifier.inherit_bounds, which is already included here --
  3196 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3197 specify an explicit context using Simplifier.context/theory_context.
  3198 
  3199 * Simplifier/Classical Reasoner: more abstract interfaces
  3200 change_simpset/claset for modifying the simpset/claset reference of a
  3201 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3202 INCOMPATIBILITY.
  3203 
  3204 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3205 "Trueprop" etc.
  3206 
  3207 
  3208 *** System ***
  3209 
  3210 * settings: the default heap location within ISABELLE_HOME_USER now
  3211 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3212 Isabelle installations.
  3213 
  3214 * isabelle-process: option -S (secure mode) disables some critical
  3215 operations, notably runtime compilation and evaluation of ML source
  3216 code.
  3217 
  3218 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3219 
  3220 * Support for parallel execution, using native multicore support of
  3221 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3222 independent theories, according to the given theory header
  3223 specifications. The maximum number of worker threads is specified via
  3224 usedir option -M or the "max-threads" setting in Proof General. A
  3225 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3226 to 6 on a 8-core machine.  User-code needs to observe certain
  3227 guidelines for thread-safe programming, see appendix A in the Isar
  3228 Implementation manual.
  3229 
  3230 
  3231 
  3232 New in Isabelle2005 (October 2005)
  3233 ----------------------------------
  3234 
  3235 *** General ***
  3236 
  3237 * Theory headers: the new header syntax for Isar theories is
  3238 
  3239   theory <name>
  3240   imports <theory1> ... <theoryN>
  3241   uses <file1> ... <fileM>
  3242   begin
  3243 
  3244 where the 'uses' part is optional.  The previous syntax
  3245 
  3246   theory <name> = <theory1> + ... + <theoryN>:
  3247 
  3248 will disappear in the next release.  Use isatool fixheaders to convert
  3249 existing theory files.  Note that there is no change in ancient
  3250 non-Isar theories now, but these will disappear soon.
  3251 
  3252 * Theory loader: parent theories can now also be referred to via
  3253 relative and absolute paths.
  3254 
  3255 * Command 'find_theorems' searches for a list of criteria instead of a
  3256 list of constants. Known criteria are: intro, elim, dest, name:string,
  3257 simp:term, and any term. Criteria can be preceded by '-' to select
  3258 theorems that do not match. Intro, elim, dest select theorems that
  3259 match the current goal, name:s selects theorems whose fully qualified
  3260 name contain s, and simp:term selects all simplification rules whose
  3261 lhs match term.  Any other term is interpreted as pattern and selects
  3262 all theorems matching the pattern. Available in ProofGeneral under
  3263 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3264 
  3265   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3266 
  3267 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3268 matching the current goal as introduction rule and not having "HOL."
  3269 in their name (i.e. not being defined in theory HOL).
  3270 
  3271 * Command 'thms_containing' has been discontinued in favour of
  3272 'find_theorems'; INCOMPATIBILITY.
  3273 
  3274 * Communication with Proof General is now 8bit clean, which means that
  3275 Unicode text in UTF-8 encoding may be used within theory texts (both
  3276 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3277 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3278 
  3279   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3280   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3281 
  3282 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3283 Classical Reasoner.  Typical big applications run around 2 times
  3284 faster.
  3285 
  3286 
  3287 *** Document preparation ***
  3288 
  3289 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3290 of raw sources.  Only those symbols that do not require additional
  3291 LaTeX packages (depending on comments in isabellesym.sty) are
  3292 displayed properly, everything else is left verbatim.  isatool display
  3293 and isatool print are used as front ends (these are subject to the
  3294 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3295 
  3296 * Command tags control specific markup of certain regions of text,
  3297 notably folding and hiding.  Predefined tags include "theory" (for
  3298 theory begin and end), "proof" for proof commands, and "ML" for
  3299 commands involving ML code; the additional tags "visible" and
  3300 "invisible" are unused by default.  Users may give explicit tag
  3301 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3302 interpretation of tags is determined by the LaTeX job during document
  3303 preparation: see option -V of isatool usedir, or options -n and -t of
  3304 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3305 \isadroptag.
  3306 
  3307 Several document versions may be produced at the same time via isatool
  3308 usedir (the generated index.html will link all of them).  Typical
  3309 specifications include ''-V document=theory,proof,ML'' to present
  3310 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3311 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3312 these parts without any formal replacement text.  The Isabelle site
  3313 default settings produce ''document'' and ''outline'' versions as
  3314 specified above.
  3315 
  3316 * Several new antiquotations:
  3317 
  3318   @{term_type term} prints a term with its type annotated;
  3319 
  3320   @{typeof term} prints the type of a term;
  3321 
  3322   @{const const} is the same as @{term const}, but checks that the
  3323   argument is a known logical constant;
  3324 
  3325   @{term_style style term} and @{thm_style style thm} print a term or
  3326   theorem applying a "style" to it
  3327 
  3328   @{ML text}
  3329 
  3330 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3331 definitions, equations, inequations etc., 'concl' printing only the
  3332 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3333 to print the specified premise.  TermStyle.add_style provides an ML
  3334 interface for introducing further styles.  See also the "LaTeX Sugar"
  3335 document practical applications.  The ML antiquotation prints
  3336 type-checked ML expressions verbatim.
  3337 
  3338 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3339 and 'text' support optional locale specification '(in loc)', which
  3340 specifies the default context for interpreting antiquotations.  For
  3341 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3342 
  3343 * Option 'locale=NAME' of antiquotations specifies an alternative
  3344 context interpreting the subsequent argument.  For example: @{thm
  3345 [locale=lattice] inf_assoc}.
  3346 
  3347 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3348 a proof context.
  3349 
  3350 * Proper output of antiquotations for theory commands involving a
  3351 proof context (such as 'locale' or 'theorem (in loc) ...').
  3352 
  3353 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3354 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3355 
  3356 * isatool usedir: new option -C (default true) controls whether option
  3357 -D should include a copy of the original document directory; -C false
  3358 prevents unwanted effects such as copying of administrative CVS data.
  3359 
  3360 
  3361 *** Pure ***
  3362 
  3363 * Considerably improved version of 'constdefs' command.  Now performs
  3364 automatic type-inference of declared constants; additional support for
  3365 local structure declarations (cf. locales and HOL records), see also
  3366 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3367 sequential dependencies of definitions within a single 'constdefs'
  3368 section; moreover, the declared name needs to be an identifier.  If
  3369 all fails, consider to fall back on 'consts' and 'defs' separately.
  3370 
  3371 * Improved indexed syntax and implicit structures.  First of all,
  3372 indexed syntax provides a notational device for subscripted
  3373 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3374 expressions.  Secondly, in a local context with structure
  3375 declarations, number indexes \<^sub>n or the empty index (default
  3376 number 1) refer to a certain fixed variable implicitly; option
  3377 show_structs controls printing of implicit structures.  Typical
  3378 applications of these concepts involve record types and locales.
  3379 
  3380 * New command 'no_syntax' removes grammar declarations (and
  3381 translations) resulting from the given syntax specification, which is
  3382 interpreted in the same manner as for the 'syntax' command.
  3383 
  3384 * 'Advanced' translation functions (parse_translation etc.) may depend
  3385 on the signature of the theory context being presently used for
  3386 parsing/printing, see also isar-ref manual.
  3387 
  3388 * Improved 'oracle' command provides a type-safe interface to turn an
  3389 ML expression of type theory -> T -> term into a primitive rule of
  3390 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3391 is already included here); see also FOL/ex/IffExample.thy;
  3392 INCOMPATIBILITY.
  3393 
  3394 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3395 before); "cI" is no longer bound, use "c.intro" instead.
  3396 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3397 axclasses vs. locales.
  3398 
  3399 * Improved internal renaming of symbolic identifiers -- attach primes
  3400 instead of base 26 numbers.
  3401 
  3402 * New flag show_question_marks controls printing of leading question
  3403 marks in schematic variable names.
  3404 
  3405 * In schematic variable names, *any* symbol following \<^isub> or
  3406 \<^isup> is now treated as part of the base name.  For example, the
  3407 following works without printing of awkward ".0" indexes:
  3408 
  3409   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3410     by simp
  3411 
  3412 * Inner syntax includes (*(*nested*) comments*).
  3413 
  3414 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3415 annotations as "(00...)".
  3416 
  3417 * Clear separation of logical types and nonterminals, where the latter
  3418 may only occur in 'syntax' specifications or type abbreviations.
  3419 Before that distinction was only partially implemented via type class
  3420 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3421 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3422 exotic syntax specifications may require further adaption
  3423 (e.g. Cube/Cube.thy).
  3424 
  3425 * Removed obsolete type class "logic", use the top sort {} instead.
  3426 Note that non-logical types should be declared as 'nonterminals'
  3427 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3428 specifications.
  3429 
  3430 * Attributes 'induct' and 'cases': type or set names may now be
  3431 locally fixed variables as well.
  3432 
  3433 * Simplifier: can now control the depth to which conditional rewriting
  3434 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3435 Limit.
  3436 
  3437 * Simplifier: simplification procedures may now take the current
  3438 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3439 interface), which is very useful for calling the Simplifier
  3440 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3441 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3442 low-level mk_simproc no longer applies Logic.varify internally, to
  3443 allow for use in a context of fixed variables.
  3444 
  3445 * thin_tac now works even if the assumption being deleted contains !!
  3446 or ==>.  More generally, erule now works even if the major premise of
  3447 the elimination rule contains !! or ==>.
  3448 
  3449 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3450 
  3451 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3452 from Pure, which contains all common declarations already.  Both
  3453 theories are defined via plain Isabelle/Isar .thy files.
  3454 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3455 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3456 use isatool fixcpure to adapt your theory and ML sources.
  3457 
  3458 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3459 selections of theorems in named facts via index ranges.
  3460 
  3461 * 'print_theorems': in theory mode, really print the difference
  3462 wrt. the last state (works for interactive theory development only),
  3463 in proof mode print all local facts (cf. 'print_facts');
  3464 
  3465 * 'hide': option '(open)' hides only base names.
  3466 
  3467 * More efficient treatment of intermediate checkpoints in interactive
  3468 theory development.
  3469 
  3470 * Code generator is now invoked via code_module (incremental code
  3471 generation) and code_library (modular code generation, ML structures
  3472 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3473 must be quoted when used as identifiers.
  3474 
  3475 * New 'value' command for reading, evaluating and printing terms using
  3476 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3477 quoted when used as identifier.
  3478 
  3479 
  3480 *** Locales ***
  3481 
  3482 * New commands for the interpretation of locale expressions in
  3483 theories (1), locales (2) and proof contexts (3).  These generate
  3484 proof obligations from the expression specification.  After the
  3485 obligations have been discharged, theorems of the expression are added
  3486 to the theory, target locale or proof context.  The synopsis of the
  3487 commands is a follows:
  3488 
  3489   (1) interpretation expr inst
  3490   (2) interpretation target < expr
  3491   (3) interpret expr inst
  3492 
  3493 Interpretation in theories and proof contexts require a parameter
  3494 instantiation of terms from the current context.  This is applied to
  3495 specifications and theorems of the interpreted expression.
  3496 Interpretation in locales only permits parameter renaming through the
  3497 locale expression.  Interpretation is smart in that interpretations
  3498 that are active already do not occur in proof obligations, neither are
  3499 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3500 inspect active interpretations of a particular locale.  For details,
  3501 see the Isar Reference manual.  Examples can be found in
  3502 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3503 
  3504 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3505 'interpret' instead.
  3506 
  3507 * New context element 'constrains' for adding type constraints to
  3508 parameters.
  3509 
  3510 * Context expressions: renaming of parameters with syntax
  3511 redeclaration.
  3512 
  3513 * Locale declaration: 'includes' disallowed.
  3514 
  3515 * Proper static binding of attribute syntax -- i.e. types / terms /
  3516 facts mentioned as arguments are always those of the locale definition
  3517 context, independently of the context of later invocations.  Moreover,
  3518 locale operations (renaming and type / term instantiation) are applied
  3519 to attribute arguments as expected.
  3520 
  3521 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3522 actual attributes; rare situations may require Attrib.attribute to
  3523 embed those attributes into Attrib.src that lack concrete syntax.
  3524 Attribute implementations need to cooperate properly with the static
  3525 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3526 Attrib.XXX_thm etc. already do the right thing without further
  3527 intervention.  Only unusual applications -- such as "where" or "of"
  3528 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3529 on the context and the facts involved -- may have to assign parsed
  3530 values to argument tokens explicitly.
  3531 
  3532 * Changed parameter management in theorem generation for long goal
  3533 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3534 theorem statement in rare situations.
  3535 
  3536 * Locale inspection command 'print_locale' omits notes elements.  Use
  3537 'print_locale!' to have them included in the output.
  3538 
  3539 
  3540 *** Provers ***
  3541 
  3542 * Provers/hypsubst.ML: improved version of the subst method, for
  3543 single-step rewriting: it now works in bound variable contexts. New is
  3544 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3545 rewrite a different subterm than the original subst method, which is
  3546 still available as 'simplesubst'.
  3547 
  3548 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3549 and quasi orders.
  3550 
  3551 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3552 reflexive-transitive closure of relations.
  3553 
  3554 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3555 limit (previously hard-coded with a value of 20) user-definable.
  3556 
  3557 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3558 is peformed already.  Object-logics merely need to finish their
  3559 initial simpset configuration as before.  INCOMPATIBILITY.
  3560 
  3561 
  3562 *** HOL ***
  3563 
  3564 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3565 
  3566   syntax (epsilon)
  3567     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3568 
  3569 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3570 and x-symbol; use option '-m epsilon' to get it actually printed.
  3571 Moreover, the mathematically important symbolic identifier \<epsilon>
  3572 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3573 
  3574 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3575 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3576 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3577 support corresponding Isar calculations.
  3578 
  3579 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3580 instead of ":".
  3581 
  3582 * theory SetInterval: changed the syntax for open intervals:
  3583 
  3584   Old       New
  3585   {..n(}    {..<n}
  3586   {)n..}    {n<..}
  3587   {m..n(}   {m..<n}
  3588   {)m..n}   {m<..n}
  3589   {)m..n(}  {m<..<n}
  3590 
  3591 The old syntax is still supported but will disappear in the next
  3592 release.  For conversion use the following Emacs search and replace
  3593 patterns (these are not perfect but work quite well):
  3594 
  3595   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3596   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3597 
  3598 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3599 equalities in commutative rings; method 'algebra' provides a generic
  3600 interface.
  3601 
  3602 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3603 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3604 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3605 be a tuple pattern.
  3606 
  3607 Some new syntax forms are available:
  3608 
  3609   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3610   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3611   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3612   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3613 
  3614 The latter form "\<Sum>x < k. e" used to be based on a separate
  3615 function "Summation", which has been discontinued.
  3616 
  3617 * theory Finite_Set: in structured induction proofs, the insert case
  3618 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3619 (insert F x)'.
  3620 
  3621 * The 'refute' command has been extended to support a much larger
  3622 fragment of HOL, including axiomatic type classes, constdefs and
  3623 typedefs, inductive datatypes and recursion.
  3624 
  3625 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3626 Requires zChaff with proof generation to be installed.  See
  3627 HOL/ex/SAT_Examples.thy for examples.
  3628 
  3629 * Datatype induction via method 'induct' now preserves the name of the
  3630 induction variable. For example, when proving P(xs::'a list) by
  3631 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3632 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3633 in unstructured proof scripts.
  3634 
  3635 * Reworked implementation of records.  Improved scalability for
  3636 records with many fields, avoiding performance problems for type
  3637 inference. Records are no longer composed of nested field types, but
  3638 of nested extension types. Therefore the record type only grows linear
  3639 in the number of extensions and not in the number of fields.  The
  3640 top-level (users) view on records is preserved.  Potential
  3641 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3642 old record representation. The type generated for a record is called
  3643 <record_name>_ext_type.
  3644 
  3645 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3646 proofs triggered by a record definition or a simproc (if
  3647 quick_and_dirty is enabled).  Definitions of large records can take
  3648 quite long.
  3649 
  3650 New simproc record_upd_simproc for simplification of multiple record
  3651 updates enabled by default.  Moreover, trivial updates are also
  3652 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3653 occasionally, since simplification is more powerful by default.
  3654 
  3655 * typedef: proper support for polymorphic sets, which contain extra
  3656 type-variables in the term.
  3657 
  3658 * Simplifier: automatically reasons about transitivity chains
  3659 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3660 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3661 old proofs break occasionally as simplification may now solve more
  3662 goals than previously.
  3663 
  3664 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3665 present.  Works for all partial orders (class "order"), in particular
  3666 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3667 just like y <= x.
  3668 
  3669 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3670 bound variable or a constant then the let is unfolded.  Otherwise
  3671 first a is simplified to b, and then f b is simplified to g. If
  3672 possible we abstract b from g arriving at "let x = b in h x",
  3673 otherwise we unfold the let and arrive at g.  The simproc can be
  3674 enabled/disabled by the reference use_let_simproc.  Potential
  3675 INCOMPATIBILITY since simplification is more powerful by default.
  3676 
  3677 * Classical reasoning: the meson method now accepts theorems as arguments.
  3678 
  3679 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3680 jobs to provide advice on the provability of subgoals.
  3681 
  3682 * Theory OrderedGroup and Ring_and_Field: various additions and
  3683 improvements to faciliate calculations involving equalities and
  3684 inequalities.
  3685 
  3686 The following theorems have been eliminated or modified
  3687 (INCOMPATIBILITY):
  3688 
  3689   abs_eq             now named abs_of_nonneg
  3690   abs_of_ge_0        now named abs_of_nonneg
  3691   abs_minus_eq       now named abs_of_nonpos
  3692   imp_abs_id         now named abs_of_nonneg
  3693   imp_abs_neg_id     now named abs_of_nonpos
  3694   mult_pos           now named mult_pos_pos
  3695   mult_pos_le        now named mult_nonneg_nonneg
  3696   mult_pos_neg_le    now named mult_nonneg_nonpos
  3697   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3698   mult_neg           now named mult_neg_neg
  3699   mult_neg_le        now named mult_nonpos_nonpos
  3700 
  3701 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3702      
  3703      zero_le_square
  3704      not_square_less_zero 
  3705 
  3706   The following lemmas have been deleted from Real/RealPow:
  3707   
  3708      realpow_zero_zero
  3709      realpow_two
  3710      realpow_less
  3711      zero_le_power
  3712      realpow_two_le
  3713      abs_realpow_two
  3714      realpow_two_abs     
  3715 
  3716 * Theory Parity: added rules for simplifying exponents.
  3717 
  3718 * Theory List:
  3719 
  3720 The following theorems have been eliminated or modified
  3721 (INCOMPATIBILITY):
  3722 
  3723   list_all_Nil       now named list_all.simps(1)
  3724   list_all_Cons      now named list_all.simps(2)
  3725   list_all_conv      now named list_all_iff
  3726   set_mem_eq         now named mem_iff
  3727 
  3728 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3729 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3730 
  3731 
  3732 *** HOL-Complex ***
  3733 
  3734 * Theory RealDef: better support for embedding natural numbers and
  3735 integers in the reals.
  3736 
  3737 The following theorems have been eliminated or modified
  3738 (INCOMPATIBILITY):
  3739 
  3740   exp_ge_add_one_self  now requires no hypotheses
  3741   real_of_int_add      reversed direction of equality (use [symmetric])
  3742   real_of_int_minus    reversed direction of equality (use [symmetric])
  3743   real_of_int_diff     reversed direction of equality (use [symmetric])
  3744   real_of_int_mult     reversed direction of equality (use [symmetric])
  3745 
  3746 * Theory RComplete: expanded support for floor and ceiling functions.
  3747 
  3748 * Theory Ln is new, with properties of the natural logarithm
  3749 
  3750 * Hyperreal: There is a new type constructor "star" for making
  3751 nonstandard types.  The old type names are now type synonyms:
  3752 
  3753   hypreal = real star
  3754   hypnat = nat star
  3755   hcomplex = complex star
  3756 
  3757 * Hyperreal: Many groups of similarly-defined constants have been
  3758 replaced by polymorphic versions (INCOMPATIBILITY):
  3759 
  3760   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3761 
  3762   starset      <-- starsetNat, starsetC
  3763   *s*          <-- *sNat*, *sc*
  3764   starset_n    <-- starsetNat_n, starsetC_n
  3765   *sn*         <-- *sNatn*, *scn*
  3766   InternalSets <-- InternalNatSets, InternalCSets
  3767 
  3768   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3769   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3770   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3771   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3772   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3773 
  3774 * Hyperreal: Many type-specific theorems have been removed in favor of
  3775 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3776 
  3777   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3778   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3779   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3780   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3781   right_minus <-- hypreal_add_minus
  3782   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3783   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3784   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3785   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3786   mult_1_right <-- hcomplex_mult_one_right
  3787   mult_zero_left <-- hcomplex_mult_zero_left
  3788   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3789   right_distrib <-- hypnat_add_mult_distrib2
  3790   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3791   right_inverse <-- hypreal_mult_inverse
  3792   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3793   order_refl <-- {hypreal,hypnat}_le_refl
  3794   order_trans <-- {hypreal,hypnat}_le_trans
  3795   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3796   order_less_le <-- {hypreal,hypnat}_less_le
  3797   linorder_linear <-- {hypreal,hypnat}_le_linear
  3798   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3799   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3800   add_nonneg_nonneg <-- hypreal_le_add_order
  3801 
  3802 * Hyperreal: Separate theorems having to do with type-specific
  3803 versions of constants have been merged into theorems that apply to the
  3804 new polymorphic constants (INCOMPATIBILITY):
  3805 
  3806   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3807   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3808   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3809   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3810   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3811   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3812   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3813   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3814   STAR_diff <-- {STAR,STARC}_diff
  3815   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3816     STARC_hcomplex_of_complex}_image_subset
  3817   starset_n_Un <-- starset{Nat,C}_n_Un
  3818   starset_n_Int <-- starset{Nat,C}_n_Int
  3819   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3820   starset_n_diff <-- starset{Nat,C}_n_diff
  3821   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3822   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3823   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3824   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3825   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3826   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3827   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3828   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3829   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3830   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3831   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3832   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3833   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3834   starfun_diff <-- starfun{C,RC,CR}_diff
  3835   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3836   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3837   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3838   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3839   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3840   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3841   starfun_Id <-- starfunC_Id
  3842   starfun_approx <-- starfun{Nat,CR}_approx
  3843   starfun_capprox <-- starfun{C,RC}_capprox
  3844   starfun_abs <-- starfunNat_rabs
  3845   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3846   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3847   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3848   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3849   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3850   starfun_add_approx <-- starfunCR_add_approx
  3851   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3852   starfun_divide <-- starfun{C,CR,RC}_divide
  3853   starfun_n <-- starfun{Nat,C}_n
  3854   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3855   starfun_n_add <-- starfun{Nat,C}_n_add
  3856   starfun_n_add_minus <-- starfunNat_n_add_minus
  3857   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3858   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3859   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3860 
  3861   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3862   star_n_minus <-- {hypreal,hcomplex}_minus
  3863   star_n_diff <-- {hypreal,hcomplex}_diff
  3864   star_n_mult <-- {hypreal,hcomplex}_mult
  3865   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3866   star_n_le <-- {hypreal,hypnat}_le
  3867   star_n_less <-- {hypreal,hypnat}_less
  3868   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3869   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3870   star_n_abs <-- hypreal_hrabs
  3871   star_n_divide <-- hcomplex_divide
  3872 
  3873   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3874   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3875   star_of_diff <-- hypreal_of_real_diff
  3876   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3877   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3878   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3879   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3880   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3881   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3882   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3883   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3884   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3885   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3886   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3887   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3888   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3889   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3890   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3891   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3892   star_of_power <-- hypreal_of_real_power
  3893   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3894 
  3895 * Hyperreal: new method "transfer" that implements the transfer
  3896 principle of nonstandard analysis. With a subgoal that mentions
  3897 nonstandard types like "'a star", the command "apply transfer"
  3898 replaces it with an equivalent one that mentions only standard types.
  3899 To be successful, all free variables must have standard types; non-
  3900 standard variables must have explicit universal quantifiers.
  3901 
  3902 * Hyperreal: A theory of Taylor series.
  3903 
  3904 
  3905 *** HOLCF ***
  3906 
  3907 * Discontinued special version of 'constdefs' (which used to support
  3908 continuous functions) in favor of the general Pure one with full
  3909 type-inference.
  3910 
  3911 * New simplification procedure for solving continuity conditions; it
  3912 is much faster on terms with many nested lambda abstractions (cubic
  3913 instead of exponential time).
  3914 
  3915 * New syntax for domain package: selector names are now optional.
  3916 Parentheses should be omitted unless argument is lazy, for example:
  3917 
  3918   domain 'a stream = cons "'a" (lazy "'a stream")
  3919 
  3920 * New command 'fixrec' for defining recursive functions with pattern
  3921 matching; defining multiple functions with mutual recursion is also
  3922 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3923 sinr, or any data constructor defined by the domain package. The given
  3924 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3925 syntax and examples.
  3926 
  3927 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3928 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3929 but the proof obligation additionally includes an admissibility
  3930 requirement. The packages generate instances of class cpo or pcpo,
  3931 with continuity and strictness theorems for Rep and Abs.
  3932 
  3933 * HOLCF: Many theorems have been renamed according to a more standard naming
  3934 scheme (INCOMPATIBILITY):
  3935 
  3936   foo_inject:  "foo$x = foo$y ==> x = y"
  3937   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3938   foo_less:    "(foo$x << foo$y) = (x << y)"
  3939   foo_strict:  "foo$UU = UU"
  3940   foo_defined: "... ==> foo$x ~= UU"
  3941   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3942 
  3943 
  3944 *** ZF ***
  3945 
  3946 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3947 including the First Isomorphism Theorem (on quotienting by the kernel
  3948 of a homomorphism).
  3949 
  3950 * ZF/Simplifier: install second copy of type solver that actually
  3951 makes use of TC rules declared to Isar proof contexts (or locales);
  3952 the old version is still required for ML proof scripts.
  3953 
  3954 
  3955 *** Cube ***
  3956 
  3957 * Converted to Isar theory format; use locales instead of axiomatic
  3958 theories.
  3959 
  3960 
  3961 *** ML ***
  3962 
  3963 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3964 for ||>, ||>>, |>>,
  3965 
  3966 * Pure/library.ML no longer defines its own option datatype, but uses
  3967 that of the SML basis, which has constructors NONE and SOME instead of
  3968 None and Some, as well as exception Option.Option instead of OPTION.
  3969 The functions the, if_none, is_some, is_none have been adapted
  3970 accordingly, while Option.map replaces apsome.
  3971 
  3972 * Pure/library.ML: the exception LIST has been given up in favour of
  3973 the standard exceptions Empty and Subscript, as well as
  3974 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3975 superceded by the standard hd and tl functions etc.
  3976 
  3977 A number of basic list functions are no longer exported to the ML
  3978 toplevel, as they are variants of predefined functions.  The following
  3979 suggests how one can translate existing code:
  3980 
  3981     rev_append xs ys = List.revAppend (xs, ys)
  3982     nth_elem (i, xs) = List.nth (xs, i)
  3983     last_elem xs = List.last xs
  3984     flat xss = List.concat xss
  3985     seq fs = List.app fs
  3986     partition P xs = List.partition P xs
  3987     mapfilter f xs = List.mapPartial f xs
  3988 
  3989 * Pure/library.ML: several combinators for linear functional
  3990 transformations, notably reverse application and composition:
  3991 
  3992   x |> f                f #> g
  3993   (x, y) |-> f          f #-> g
  3994 
  3995 * Pure/library.ML: introduced/changed precedence of infix operators:
  3996 
  3997   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3998   infix 2 ?;
  3999   infix 3 o oo ooo oooo;
  4000   infix 4 ~~ upto downto;
  4001 
  4002 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  4003 infix operators.
  4004 
  4005 * Pure/library.ML: natural list combinators fold, fold_rev, and
  4006 fold_map support linear functional transformations and nesting.  For
  4007 example:
  4008 
  4009   fold f [x1, ..., xN] y =
  4010     y |> f x1 |> ... |> f xN
  4011 
  4012   (fold o fold) f [xs1, ..., xsN] y =
  4013     y |> fold f xs1 |> ... |> fold f xsN
  4014 
  4015   fold f [x1, ..., xN] =
  4016     f x1 #> ... #> f xN
  4017 
  4018   (fold o fold) f [xs1, ..., xsN] =
  4019     fold f xs1 #> ... #> fold f xsN
  4020 
  4021 * Pure/library.ML: the following selectors on type 'a option are
  4022 available:
  4023 
  4024   the:               'a option -> 'a  (*partial*)
  4025   these:             'a option -> 'a  where 'a = 'b list
  4026   the_default: 'a -> 'a option -> 'a
  4027   the_list:          'a option -> 'a list
  4028 
  4029 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4030 basic operations for association lists, following natural argument
  4031 order; moreover the explicit equality predicate passed here avoids
  4032 potentially expensive polymorphic runtime equality checks.
  4033 The old functions may be expressed as follows:
  4034 
  4035   assoc = uncurry (AList.lookup (op =))
  4036   assocs = these oo AList.lookup (op =)
  4037   overwrite = uncurry (AList.update (op =)) o swap
  4038 
  4039 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  4040 
  4041   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  4042   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  4043 
  4044 replacing make_keylist and keyfilter (occassionally used)
  4045 Naive rewrites:
  4046 
  4047   make_keylist = AList.make
  4048   keyfilter = AList.find (op =)
  4049 
  4050 * eq_fst and eq_snd now take explicit equality parameter, thus
  4051   avoiding eqtypes. Naive rewrites:
  4052 
  4053     eq_fst = eq_fst (op =)
  4054     eq_snd = eq_snd (op =)
  4055 
  4056 * Removed deprecated apl and apr (rarely used).
  4057   Naive rewrites:
  4058 
  4059     apl (n, op) =>>= curry op n
  4060     apr (op, m) =>>= fn n => op (n, m)
  4061 
  4062 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  4063 provides a reasonably efficient light-weight implementation of sets as
  4064 lists.
  4065 
  4066 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  4067 few new operations; existing lookup and update are now curried to
  4068 follow natural argument order (for use with fold etc.);
  4069 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  4070 
  4071 * Pure/General: output via the Isabelle channels of
  4072 writeln/warning/error etc. is now passed through Output.output, with a
  4073 hook for arbitrary transformations depending on the print_mode
  4074 (cf. Output.add_mode -- the first active mode that provides a output
  4075 function wins).  Already formatted output may be embedded into further
  4076 text via Output.raw; the result of Pretty.string_of/str_of and derived
  4077 functions (string_of_term/cterm/thm etc.) is already marked raw to
  4078 accommodate easy composition of diagnostic messages etc.  Programmers
  4079 rarely need to care about Output.output or Output.raw at all, with
  4080 some notable exceptions: Output.output is required when bypassing the
  4081 standard channels (writeln etc.), or in token translations to produce
  4082 properly formatted results; Output.raw is required when capturing
  4083 already output material that will eventually be presented to the user
  4084 a second time.  For the default print mode, both Output.output and
  4085 Output.raw have no effect.
  4086 
  4087 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  4088 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  4089 cumulative results are displayed at the end of a batch session.
  4090 
  4091 * Pure/General: File.sysify_path and File.quote_sysify path have been
  4092 replaced by File.platform_path and File.shell_path (with appropriate
  4093 hooks).  This provides a clean interface for unusual systems where the
  4094 internal and external process view of file names are different.
  4095 
  4096 * Pure: more efficient orders for basic syntactic entities: added
  4097 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  4098 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  4099 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  4100 orders now -- potential INCOMPATIBILITY for code that depends on a
  4101 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  4102 Library.sort_strings on result).
  4103 
  4104 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  4105 fold_types traverse types/terms from left to right, observing natural
  4106 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  4107 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  4108 
  4109 * Pure: name spaces have been refined, with significant changes of the
  4110 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  4111 to extern(_table).  The plain name entry path is superceded by a
  4112 general 'naming' context, which also includes the 'policy' to produce
  4113 a fully qualified name and external accesses of a fully qualified
  4114 name; NameSpace.extend is superceded by context dependent
  4115 Sign.declare_name.  Several theory and proof context operations modify
  4116 the naming context.  Especially note Theory.restore_naming and
  4117 ProofContext.restore_naming to get back to a sane state; note that
  4118 Theory.add_path is no longer sufficient to recover from
  4119 Theory.absolute_path in particular.
  4120 
  4121 * Pure: new flags short_names (default false) and unique_names
  4122 (default true) for controlling output of qualified names.  If
  4123 short_names is set, names are printed unqualified.  If unique_names is
  4124 reset, the name prefix is reduced to the minimum required to achieve
  4125 the original result when interning again, even if there is an overlap
  4126 with earlier declarations.
  4127 
  4128 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  4129 now 'extend', and 'merge' gets an additional Pretty.pp argument
  4130 (useful for printing error messages).  INCOMPATIBILITY.
  4131 
  4132 * Pure: major reorganization of the theory context.  Type Sign.sg and
  4133 Theory.theory are now identified, referring to the universal
  4134 Context.theory (see Pure/context.ML).  Actual signature and theory
  4135 content is managed as theory data.  The old code and interfaces were
  4136 spread over many files and structures; the new arrangement introduces
  4137 considerable INCOMPATIBILITY to gain more clarity:
  4138 
  4139   Context -- theory management operations (name, identity, inclusion,
  4140     parents, ancestors, merge, etc.), plus generic theory data;
  4141 
  4142   Sign -- logical signature and syntax operations (declaring consts,
  4143     types, etc.), plus certify/read for common entities;
  4144 
  4145   Theory -- logical theory operations (stating axioms, definitions,
  4146     oracles), plus a copy of logical signature operations (consts,
  4147     types, etc.); also a few basic management operations (Theory.copy,
  4148     Theory.merge, etc.)
  4149 
  4150 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  4151 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  4152 for convenience -- they merely return the theory.
  4153 
  4154 * Pure: type Type.tsig is superceded by theory in most interfaces.
  4155 
  4156 * Pure: the Isar proof context type is already defined early in Pure
  4157 as Context.proof (note that ProofContext.context and Proof.context are
  4158 aliases, where the latter is the preferred name).  This enables other
  4159 Isabelle components to refer to that type even before Isar is present.
  4160 
  4161 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4162 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4163 any of these kinds.  For example, Sign.intern typeK is now
  4164 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4165 Theory.hide_types.  Also note that former
  4166 Theory.hide_classes/types/consts are now
  4167 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4168 internalize their arguments!  INCOMPATIBILITY.
  4169 
  4170 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4171 datatype thmref (with constructors Name and NameSelection) instead of
  4172 plain string -- INCOMPATIBILITY;
  4173 
  4174 * Pure: cases produced by proof methods specify options, where NONE
  4175 means to remove case bindings -- INCOMPATIBILITY in
  4176 (RAW_)METHOD_CASES.
  4177 
  4178 * Pure: the following operations retrieve axioms or theorems from a
  4179 theory node or theory hierarchy, respectively:
  4180 
  4181   Theory.axioms_of: theory -> (string * term) list
  4182   Theory.all_axioms_of: theory -> (string * term) list
  4183   PureThy.thms_of: theory -> (string * thm) list
  4184   PureThy.all_thms_of: theory -> (string * thm) list
  4185 
  4186 * Pure: print_tac now outputs the goal through the trace channel.
  4187 
  4188 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4189 Reference Toplevel.debug (default false) controls detailed printing
  4190 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4191 controls execution profiling -- set to 1 for time and 2 for space
  4192 (both increase the runtime).
  4193 
  4194 * Isar session: The initial use of ROOT.ML is now always timed,
  4195 i.e. the log will show the actual process times, in contrast to the
  4196 elapsed wall-clock time that the outer shell wrapper produces.
  4197 
  4198 * Simplifier: improved handling of bound variables (nameless
  4199 representation, avoid allocating new strings).  Simprocs that invoke
  4200 the Simplifier recursively should use Simplifier.inherit_bounds to
  4201 avoid local name clashes.  Failure to do so produces warnings
  4202 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4203 for further details.
  4204 
  4205 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4206 bindings for all theorems stored within a given theory; this may help
  4207 in porting non-Isar theories to Isar ones, while keeping ML proof
  4208 scripts for the time being.
  4209 
  4210 * ML operator HTML.with_charset specifies the charset begin used for
  4211 generated HTML files.  For example:
  4212 
  4213   HTML.with_charset "utf-8" use_thy "Hebrew";
  4214   HTML.with_charset "utf-8" use_thy "Chinese";
  4215 
  4216 
  4217 *** System ***
  4218 
  4219 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4220 isabelle, isatool etc.).
  4221 
  4222 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4223 isatool doc, isatool mkdir, display_drafts etc.).
  4224 
  4225 * isatool usedir: option -f allows specification of the ML file to be
  4226 used by Isabelle; default is ROOT.ML.
  4227 
  4228 * New isatool version outputs the version identifier of the Isabelle
  4229 distribution being used.
  4230 
  4231 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4232 (containing Boolean satisfiability problems) into Isabelle/HOL
  4233 theories.
  4234 
  4235 
  4236 
  4237 New in Isabelle2004 (April 2004)
  4238 --------------------------------
  4239 
  4240 *** General ***
  4241 
  4242 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4243   Replaces linorder.ML.
  4244 
  4245 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4246   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4247   (\<a>...\<z>), are now considered normal letters, and can therefore
  4248   be used anywhere where an ASCII letter (a...zA...Z) has until
  4249   now. COMPATIBILITY: This obviously changes the parsing of some
  4250   terms, especially where a symbol has been used as a binder, say
  4251   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4252   as an identifier.  Fix it by inserting a space around former
  4253   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4254   existing theory and ML files.
  4255 
  4256 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4257 
  4258 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4259   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4260   a normal (but invisible) letter. For multiple letter subscripts repeat
  4261   \<^isub> like this: x\<^isub>1\<^isub>2.
  4262 
  4263 * Pure: There are now sub-/superscripts that can span more than one
  4264   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4265   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4266   superscript. The new control characters are not identifier parts.
  4267 
  4268 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4269   content of "..." to the latex file instead of \isacntrl... . The "..."
  4270   may consist of any printable characters excluding the end bracket >.
  4271 
  4272 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4273   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4274   declare constants "final", which prevents their being given a definition
  4275   later.  It is useful for constants whose behaviour is fixed axiomatically
  4276   rather than definitionally, such as the meta-logic connectives.
  4277 
  4278 * Pure: 'instance' now handles general arities with general sorts
  4279   (i.e. intersections of classes),
  4280 
  4281 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4282   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4283   It can be changed to alter the colors/layout of generated pages.
  4284 
  4285 
  4286 *** Isar ***
  4287 
  4288 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4289   cut_tac, subgoal_tac and thin_tac:
  4290   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4291     locales are no longer forced to write Isar proof scripts.
  4292     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4293     emulations.
  4294   - INCOMPATIBILITY: names of variables to be instantiated may no
  4295     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4296     This is consistent with the instantiation attribute "where".
  4297 
  4298 * Attributes "where" and "of":
  4299   - Now take type variables of instantiated theorem into account when reading
  4300     the instantiation string.  This fixes a bug that caused instantiated
  4301     theorems to have too special types in some circumstances.
  4302   - "where" permits explicit instantiations of type variables.
  4303 
  4304 * Calculation commands "moreover" and "also" no longer interfere with
  4305   current facts ("this"), admitting arbitrary combinations with "then"
  4306   and derived forms.
  4307 
  4308 * Locales:
  4309   - Goal statements involving the context element "includes" no longer
  4310     generate theorems with internal delta predicates (those ending on
  4311     "_axioms") in the premise.
  4312     Resolve particular premise with <locale>.intro to obtain old form.
  4313   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4314     specification and "includes" elements in goal statement.
  4315   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4316     [intro?] and [elim?] (respectively) by default.
  4317   - Experimental command for instantiation of locales in proof contexts:
  4318         instantiate <label>[<attrs>]: <loc>
  4319     Instantiates locale <loc> and adds all its theorems to the current context
  4320     taking into account their attributes.  Label and attrs are optional
  4321     modifiers, like in theorem declarations.  If present, names of
  4322     instantiated theorems are qualified with <label>, and the attributes
  4323     <attrs> are applied after any attributes these theorems might have already.
  4324       If the locale has assumptions, a chained fact of the form
  4325     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4326     are derived.  The command does not support old-style locales declared
  4327     with "locale (open)".
  4328       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4329 
  4330 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4331   (Isar) contexts.
  4332 
  4333 
  4334 *** HOL ***
  4335 
  4336 * Proof import: new image HOL4 contains the imported library from
  4337   the HOL4 system with about 2500 theorems. It is imported by
  4338   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4339   can be used like any other Isabelle image.  See
  4340   HOL/Import/HOL/README for more information.
  4341 
  4342 * Simplifier:
  4343   - Much improved handling of linear and partial orders.
  4344     Reasoners for linear and partial orders are set up for type classes
  4345     "linorder" and "order" respectively, and are added to the default simpset
  4346     as solvers.  This means that the simplifier can build transitivity chains
  4347     to solve goals from the assumptions.
  4348   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4349     of blast or auto after simplification become unnecessary because the goal
  4350     is solved by simplification already.
  4351 
  4352 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4353     all proved in axiomatic type classes for semirings, rings and fields.
  4354 
  4355 * Numerics:
  4356   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4357     now formalized using the Ring_and_Field theory mentioned above.
  4358   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4359     than before, because now they are set up once in a generic manner.
  4360   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4361     Look for the general versions in Ring_and_Field (and Power if they concern
  4362     exponentiation).
  4363 
  4364 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4365 
  4366 * Records:
  4367   - Record types are now by default printed with their type abbreviation
  4368     instead of the list of all field types. This can be configured via
  4369     the reference "print_record_type_abbr".
  4370   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4371     (not enabled by default).
  4372   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4373     EX x. x = sel r to True (not enabled by default).
  4374   - Tactic "record_split_simp_tac" to split and simplify records added.
  4375 
  4376 * 'specification' command added, allowing for definition by
  4377   specification.  There is also an 'ax_specification' command that
  4378   introduces the new constants axiomatically.
  4379 
  4380 * arith(_tac) is now able to generate counterexamples for reals as well.
  4381 
  4382 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4383 
  4384 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4385   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4386 
  4387 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4388   matrix theory to linear programming.
  4389 
  4390 * Unions and Intersections:
  4391   The latex output syntax of UN and INT has been changed
  4392   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4393   i.e. the index formulae has become a subscript.
  4394   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4395 
  4396 * Unions and Intersections over Intervals:
  4397   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4398   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4399   like in normal math, and corresponding versions for < and for intersection.
  4400 
  4401 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4402   lexicographic dictonary ordering has been added as "lexord".
  4403 
  4404 * ML: the legacy theory structures Int and List have been removed. They had
  4405   conflicted with ML Basis Library structures having the same names.
  4406 
  4407 * 'refute' command added to search for (finite) countermodels.  Only works
  4408   for a fragment of HOL.  The installation of an external SAT solver is
  4409   highly recommended.  See "HOL/Refute.thy" for details.
  4410 
  4411 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4412   formulae under an assignment of free variables to random values.
  4413   In contrast to 'refute', it can deal with inductive datatypes,
  4414   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4415   for examples.
  4416 
  4417 
  4418 *** HOLCF ***
  4419 
  4420 * Streams now come with concatenation and are part of the HOLCF image
  4421 
  4422 
  4423 
  4424 New in Isabelle2003 (May 2003)
  4425 ------------------------------
  4426 
  4427 *** General ***
  4428 
  4429 * Provers/simplifier:
  4430 
  4431   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4432     Assumptions are now subject to complete mutual simplification,
  4433     not just from left to right. The simplifier now preserves
  4434     the order of assumptions.
  4435 
  4436     Potential INCOMPATIBILITY:
  4437 
  4438     -- simp sometimes diverges where the old version did
  4439        not, e.g. invoking simp on the goal
  4440 
  4441         [| P (f x); y = x; f x = f y |] ==> Q
  4442 
  4443        now gives rise to the infinite reduction sequence
  4444 
  4445         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4446 
  4447        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4448        kind of problem.
  4449 
  4450     -- Tactics combining classical reasoner and simplification (such as auto)
  4451        are also affected by this change, because many of them rely on
  4452        simp. They may sometimes diverge as well or yield a different numbers
  4453        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4454        in case of problems. Sometimes subsequent calls to the classical
  4455        reasoner will fail because a preceeding call to the simplifier too
  4456        eagerly simplified the goal, e.g. deleted redundant premises.
  4457 
  4458   - The simplifier trace now shows the names of the applied rewrite rules
  4459 
  4460   - You can limit the number of recursive invocations of the simplifier
  4461     during conditional rewriting (where the simplifie tries to solve the
  4462     conditions before applying the rewrite rule):
  4463     ML "simp_depth_limit := n"
  4464     where n is an integer. Thus you can force termination where previously
  4465     the simplifier would diverge.
  4466 
  4467   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4468 
  4469   - No longer aborts on failed congruence proof.  Instead, the
  4470     congruence is ignored.
  4471 
  4472 * Pure: New generic framework for extracting programs from constructive
  4473   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4474   as HOL/Extraction for some case studies.
  4475 
  4476 * Pure: The main goal of the proof state is no longer shown by default, only
  4477 the subgoals. This behaviour is controlled by a new flag.
  4478    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4479 (ML: Proof.show_main_goal).
  4480 
  4481 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4482 rules whose conclusion matches subgoal 1:
  4483       PG menu: Isabelle/Isar -> Show me -> matching rules
  4484 The rules are ordered by how closely they match the subgoal.
  4485 In particular, rules that solve a subgoal outright are displayed first
  4486 (or rather last, the way they are printed).
  4487 (ML: ProofGeneral.print_intros())
  4488 
  4489 * Pure: New flag trace_unify_fail causes unification to print
  4490 diagnostic information (PG: in trace buffer) when it fails. This is
  4491 useful for figuring out why single step proofs like rule, erule or
  4492 assumption failed.
  4493 
  4494 * Pure: Locale specifications now produce predicate definitions
  4495 according to the body of text (covering assumptions modulo local
  4496 definitions); predicate "loc_axioms" covers newly introduced text,
  4497 while "loc" is cumulative wrt. all included locale expressions; the
  4498 latter view is presented only on export into the global theory
  4499 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4500 on the old view without predicates;
  4501 
  4502 * Pure: predefined locales "var" and "struct" are useful for sharing
  4503 parameters (as in CASL, for example); just specify something like
  4504 ``var x + var y + struct M'' as import;
  4505 
  4506 * Pure: improved thms_containing: proper indexing of facts instead of
  4507 raw theorems; check validity of results wrt. current name space;
  4508 include local facts of proof configuration (also covers active
  4509 locales), cover fixed variables in index; may use "_" in term
  4510 specification; an optional limit for the number of printed facts may
  4511 be given (the default is 40);
  4512 
  4513 * Pure: disallow duplicate fact bindings within new-style theory files
  4514 (batch-mode only);
  4515 
  4516 * Provers: improved induct method: assumptions introduced by case
  4517 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4518 the goal statement); "foo" still refers to all facts collectively;
  4519 
  4520 * Provers: the function blast.overloaded has been removed: all constants
  4521 are regarded as potentially overloaded, which improves robustness in exchange
  4522 for slight decrease in efficiency;
  4523 
  4524 * Provers/linorder: New generic prover for transitivity reasoning over
  4525 linear orders.  Note: this prover is not efficient!
  4526 
  4527 * Isar: preview of problems to finish 'show' now produce an error
  4528 rather than just a warning (in interactive mode);
  4529 
  4530 
  4531 *** HOL ***
  4532 
  4533 * arith(_tac)
  4534 
  4535  - Produces a counter example if it cannot prove a goal.
  4536    Note that the counter example may be spurious if the goal is not a formula
  4537    of quantifier-free linear arithmetic.
  4538    In ProofGeneral the counter example appears in the trace buffer.
  4539 
  4540  - Knows about div k and mod k where k is a numeral of type nat or int.
  4541 
  4542  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4543    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4544    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4545 
  4546 * simp's arithmetic capabilities have been enhanced a bit: it now
  4547 takes ~= in premises into account (by performing a case split);
  4548 
  4549 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4550 are distributed over a sum of terms;
  4551 
  4552 * New tactic "trans_tac" and method "trans" instantiate
  4553 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4554 "<=", "<" and "=").
  4555 
  4556 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4557 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4558 
  4559 * 'typedef' command has new option "open" to suppress the set
  4560 definition;
  4561 
  4562 * functions Min and Max on finite sets have been introduced (theory
  4563 Finite_Set);
  4564 
  4565 * attribute [symmetric] now works for relations as well; it turns
  4566 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4567 
  4568 * induct over a !!-quantified statement (say !!x1..xn):
  4569   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4570 
  4571 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4572 %x. None. Warning: empty_def now refers to the previously hidden definition
  4573 of the empty set.
  4574 
  4575 * Algebra: formalization of classical algebra.  Intended as base for
  4576 any algebraic development in Isabelle.  Currently covers group theory
  4577 (up to Sylow's theorem) and ring theory (Universal Property of
  4578 Univariate Polynomials).  Contributions welcome;
  4579 
  4580 * GroupTheory: deleted, since its material has been moved to Algebra;
  4581 
  4582 * Complex: new directory of the complex numbers with numeric constants,
  4583 nonstandard complex numbers, and some complex analysis, standard and
  4584 nonstandard (Jacques Fleuriot);
  4585 
  4586 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4587 
  4588 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4589 Fleuriot);
  4590 
  4591 * Real/HahnBanach: updated and adapted to locales;
  4592 
  4593 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4594 Gray and Kramer);
  4595 
  4596 * UNITY: added the Meier-Sanders theory of progress sets;
  4597 
  4598 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4599 as abstract algorithms, instantiated to the JVM;
  4600 
  4601 * Bali: Java source language formalization. Type system, operational
  4602 semantics, axiomatic semantics. Supported language features:
  4603 classes, interfaces, objects,virtual methods, static methods,
  4604 static/instance fields, arrays, access modifiers, definite
  4605 assignment, exceptions.
  4606 
  4607 
  4608 *** ZF ***
  4609 
  4610 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4611 universe, etc.);
  4612 
  4613 * Main ZF: virtually all theories converted to new-style format;
  4614 
  4615 
  4616 *** ML ***
  4617 
  4618 * Pure: Tactic.prove provides sane interface for internal proofs;
  4619 omits the infamous "standard" operation, so this is more appropriate
  4620 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4621 
  4622 * Pure: improved error reporting of simprocs;
  4623 
  4624 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4625 up simprocs;
  4626 
  4627 
  4628 *** Document preparation ***
  4629 
  4630 * uses \par instead of \\ for line breaks in theory text. This may
  4631 shift some page breaks in large documents. To get the old behaviour
  4632 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4633 
  4634 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4635 other packages
  4636 
  4637 * \<euro> now needs package babel/greek instead of marvosym (which
  4638 broke \Rightarrow)
  4639 
  4640 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4641 textcomp package)
  4642 
  4643 
  4644 
  4645 New in Isabelle2002 (March 2002)
  4646 --------------------------------
  4647 
  4648 *** Document preparation ***
  4649 
  4650 * greatly simplified document preparation setup, including more
  4651 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4652 instructive isatool mkdir; users should basically be able to get
  4653 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4654 users may run a separate document processing stage manually like this:
  4655 "isatool usedir -D output HOL Test && isatool document Test/output";
  4656 
  4657 * theory dependency graph may now be incorporated into documents;
  4658 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4659 with \includegraphics of LaTeX;
  4660 
  4661 * proper spacing of consecutive markup elements, especially text
  4662 blocks after section headings;
  4663 
  4664 * support bold style (for single symbols only), input syntax is like
  4665 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4666 
  4667 * \<bullet> is now output as bold \cdot by default, which looks much
  4668 better in printed text;
  4669 
  4670 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4671 note that these symbols are currently unavailable in Proof General /
  4672 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4673 
  4674 * isatool latex no longer depends on changed TEXINPUTS, instead
  4675 isatool document copies the Isabelle style files to the target
  4676 location;
  4677 
  4678 
  4679 *** Isar ***
  4680 
  4681 * Pure/Provers: improved proof by cases and induction;
  4682   - 'case' command admits impromptu naming of parameters (such as
  4683     "case (Suc n)");
  4684   - 'induct' method divinates rule instantiation from the inductive
  4685     claim; no longer requires excessive ?P bindings for proper
  4686     instantiation of cases;
  4687   - 'induct' method properly enumerates all possibilities of set/type
  4688     rules; as a consequence facts may be also passed through *type*
  4689     rules without further ado;
  4690   - 'induct' method now derives symbolic cases from the *rulified*
  4691     rule (before it used to rulify cases stemming from the internal
  4692     atomized version); this means that the context of a non-atomic
  4693     statement becomes is included in the hypothesis, avoiding the
  4694     slightly cumbersome show "PROP ?case" form;
  4695   - 'induct' may now use elim-style induction rules without chaining
  4696     facts, using ``missing'' premises from the goal state; this allows
  4697     rules stemming from inductive sets to be applied in unstructured
  4698     scripts, while still benefitting from proper handling of non-atomic
  4699     statements; NB: major inductive premises need to be put first, all
  4700     the rest of the goal is passed through the induction;
  4701   - 'induct' proper support for mutual induction involving non-atomic
  4702     rule statements (uses the new concept of simultaneous goals, see
  4703     below);
  4704   - append all possible rule selections, but only use the first
  4705     success (no backtracking);
  4706   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4707   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4708   - added 'print_induct_rules' (covered by help item in recent Proof
  4709     General versions);
  4710   - moved induct/cases attributes to Pure, methods to Provers;
  4711   - generic method setup instantiated for FOL and HOL;
  4712 
  4713 * Pure: support multiple simultaneous goal statements, for example
  4714 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4715 meta-level mechanism, this acts as if several individual goals had
  4716 been stated separately; in particular common proof methods need to be
  4717 repeated in order to cover all claims; note that a single elimination
  4718 step is *not* sufficient to establish the two conjunctions, so this
  4719 fails:
  4720 
  4721   assume "A & B" then have A and B ..   (*".." fails*)
  4722 
  4723 better use "obtain" in situations as above; alternative refer to
  4724 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4725 
  4726 * Pure: proper integration with ``locales''; unlike the original
  4727 version by Florian Kammller, Isar locales package high-level proof
  4728 contexts rather than raw logical ones (e.g. we admit to include
  4729 attributes everywhere); operations on locales include merge and
  4730 rename; support for implicit arguments (``structures''); simultaneous
  4731 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4732 some examples;
  4733 
  4734 * Pure: the following commands have been ``localized'', supporting a
  4735 target locale specification "(in name)": 'lemma', 'theorem',
  4736 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4737 stored both within the locale and at the theory level (exported and
  4738 qualified by the locale name);
  4739 
  4740 * Pure: theory goals may now be specified in ``long'' form, with
  4741 ad-hoc contexts consisting of arbitrary locale elements. for example
  4742 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4743 definitions may be given, too); the result is a meta-level rule with
  4744 the context elements being discharged in the obvious way;
  4745 
  4746 * Pure: new proof command 'using' allows to augment currently used
  4747 facts after a goal statement ('using' is syntactically analogous to
  4748 'apply', but acts on the goal's facts only); this allows chained facts
  4749 to be separated into parts given before and after a claim, as in
  4750 ``from a and b have C using d and e <proof>'';
  4751 
  4752 * Pure: renamed "antecedent" case to "rule_context";
  4753 
  4754 * Pure: new 'judgment' command records explicit information about the
  4755 object-logic embedding (used by several tools internally); no longer
  4756 use hard-wired "Trueprop";
  4757 
  4758 * Pure: added 'corollary' command;
  4759 
  4760 * Pure: fixed 'token_translation' command;
  4761 
  4762 * Pure: removed obsolete 'exported' attribute;
  4763 
  4764 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4765 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4766 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4767 
  4768 * Pure: method 'atomize' presents local goal premises as object-level
  4769 statements (atomic meta-level propositions); setup controlled via
  4770 rewrite rules declarations of 'atomize' attribute; example
  4771 application: 'induct' method with proper rule statements in improper
  4772 proof *scripts*;
  4773 
  4774 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4775 now consider the syntactic context of assumptions, giving a better
  4776 chance to get type-inference of the arguments right (this is
  4777 especially important for locales);
  4778 
  4779 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4780 mode;
  4781 
  4782 * Pure/obtain: the formal conclusion "thesis", being marked as
  4783 ``internal'', may no longer be reference directly in the text;
  4784 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4785 situations;
  4786 
  4787 * Pure: generic 'sym' attribute which declares a rule both as pure
  4788 'elim?' and for the 'symmetric' operation;
  4789 
  4790 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4791 text; the fixed correlation with particular command syntax has been
  4792 discontinued;
  4793 
  4794 * Pure: new method 'rules' is particularly well-suited for proof
  4795 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4796 but often produces more compact proof terms with less detours;
  4797 
  4798 * Pure/Provers/classical: simplified integration with pure rule
  4799 attributes and methods; the classical "intro?/elim?/dest?"
  4800 declarations coincide with the pure ones; the "rule" method no longer
  4801 includes classically swapped intros; "intro" and "elim" methods no
  4802 longer pick rules from the context; also got rid of ML declarations
  4803 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4804 INCOMPATIBILITY;
  4805 
  4806 * Provers/classical: attribute 'swapped' produces classical inversions
  4807 of introduction rules;
  4808 
  4809 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4810 rules instead of full simplifier context; 'iff' attribute handles
  4811 conditional rules;
  4812 
  4813 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4814 
  4815 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4816 "(permissive)" option to recover old behavior;
  4817 
  4818 * HOL: 'inductive' no longer features separate (collective) attributes
  4819 for 'intros' (was found too confusing);
  4820 
  4821 * HOL: properly declared induction rules less_induct and
  4822 wf_induct_rule;
  4823 
  4824 
  4825 *** HOL ***
  4826 
  4827 * HOL: moved over to sane numeral syntax; the new policy is as
  4828 follows:
  4829 
  4830   - 0 and 1 are polymorphic constants, which are defined on any
  4831   numeric type (nat, int, real etc.);
  4832 
  4833   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4834   binary representation internally;
  4835 
  4836   - type nat has special constructor Suc, and generally prefers Suc 0
  4837   over 1::nat and Suc (Suc 0) over 2::nat;
  4838 
  4839 This change may cause significant problems of INCOMPATIBILITY; here
  4840 are some hints on converting existing sources:
  4841 
  4842   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4843   entities, so expressions involving "-" (unary or binary minus) need
  4844   to be spaced properly;
  4845 
  4846   - existing occurrences of "1" may need to be constraint "1::nat" or
  4847   even replaced by Suc 0; similar for old "2";
  4848 
  4849   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4850 
  4851   - remove all special provisions on numerals in proofs;
  4852 
  4853 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4854 representation (depends on bin_arith_simps in the default context);
  4855 
  4856 * HOL: symbolic syntax for x^2 (numeral 2);
  4857 
  4858 * HOL: the class of all HOL types is now called "type" rather than
  4859 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4860 in axclass/classes, instance/arities, and (usually rare) occurrences
  4861 in typings (of consts etc.); internally the class is called
  4862 "HOL.type", ML programs should refer to HOLogic.typeS;
  4863 
  4864 * HOL/record package improvements:
  4865   - new derived operations "fields" to build a partial record section,
  4866     "extend" to promote a fixed record to a record scheme, and
  4867     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4868     declared as simp by default;
  4869   - shared operations ("more", "fields", etc.) now need to be always
  4870     qualified) --- potential INCOMPATIBILITY;
  4871   - removed "make_scheme" operations (use "make" with "extend") --
  4872     INCOMPATIBILITY;
  4873   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4874   - provides cases/induct rules for use with corresponding Isar
  4875     methods (for concrete records, record schemes, concrete more
  4876     parts, and schematic more parts -- in that order);
  4877   - internal definitions directly based on a light-weight abstract
  4878     theory of product types over typedef rather than datatype;
  4879 
  4880 * HOL: generic code generator for generating executable ML code from
  4881 specifications; specific support for HOL constructs such as inductive
  4882 datatypes and sets, as well as recursive functions; can be invoked
  4883 via 'generate_code' theory section;
  4884 
  4885 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4886 
  4887 * HOL: consolidated and renamed several theories.  In particular:
  4888         Ord.thy has been absorbed into HOL.thy
  4889         String.thy has been absorbed into List.thy
  4890 
  4891 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4892 (beware of argument permutation!);
  4893 
  4894 * HOL: linorder_less_split superseded by linorder_cases;
  4895 
  4896 * HOL/List: "nodups" renamed to "distinct";
  4897 
  4898 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4899 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4900   - Ex_def has changed, now need to use some_eq_ex
  4901 
  4902 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4903 in this (rare) case use:
  4904 
  4905   delSWrapper "split_all_tac"
  4906   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4907 
  4908 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4909 MAY FAIL;
  4910 
  4911 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4912 Isabelle's type classes, ^ on functions and relations has too general
  4913 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4914 necessary to attach explicit type constraints;
  4915 
  4916 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4917 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4918 renamed accordingly (eg "compI" -> "rel_compI").
  4919 
  4920 * HOL: syntax translations now work properly with numerals and records
  4921 expressions;
  4922 
  4923 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4924 of "lam" -- INCOMPATIBILITY;
  4925 
  4926 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4927 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4928 renamed "Product_Type.unit";
  4929 
  4930 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4931 
  4932 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4933 the "cases" method);
  4934 
  4935 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4936 Florian Kammller);
  4937 
  4938 * HOL/IMP: updated and converted to new-style theory format; several
  4939 parts turned into readable document, with proper Isar proof texts and
  4940 some explanations (by Gerwin Klein);
  4941 
  4942 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4943 
  4944 * HOL-Hyperreal is now a logic image;
  4945 
  4946 
  4947 *** HOLCF ***
  4948 
  4949 * Isar: consts/constdefs supports mixfix syntax for continuous
  4950 operations;
  4951 
  4952 * Isar: domain package adapted to new-style theory format, e.g. see
  4953 HOLCF/ex/Dnat.thy;
  4954 
  4955 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4956 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4957 lift.induct_tac, always use UU instead of Undef;
  4958 
  4959 * HOLCF/IMP: updated and converted to new-style theory;
  4960 
  4961 
  4962 *** ZF ***
  4963 
  4964 * Isar: proper integration of logic-specific tools and packages,
  4965 including theory commands '(co)inductive', '(co)datatype',
  4966 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4967 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4968 
  4969 * theory Main no longer includes AC; for the Axiom of Choice, base
  4970 your theory on Main_ZFC;
  4971 
  4972 * the integer library now covers quotients and remainders, with many
  4973 laws relating division to addition, multiplication, etc.;
  4974 
  4975 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4976 typeless version of the formalism;
  4977 
  4978 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4979 format;
  4980 
  4981 * ZF/Induct: new directory for examples of inductive definitions,
  4982 including theory Multiset for multiset orderings; converted to
  4983 new-style theory format;
  4984 
  4985 * ZF: many new theorems about lists, ordinals, etc.;
  4986 
  4987 
  4988 *** General ***
  4989 
  4990 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4991 variable proof controls level of detail: 0 = no proofs (only oracle
  4992 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4993 also ref manual for further ML interfaces;
  4994 
  4995 * Pure/axclass: removed obsolete ML interface
  4996 goal_subclass/goal_arity;
  4997 
  4998 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4999 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  5000 separate tokens, so expressions involving minus need to be spaced
  5001 properly;
  5002 
  5003 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  5004 rather than "infixl" or "infixr";
  5005 
  5006 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  5007 sort constraint specifications in type inference; e.g. "x::_::foo"
  5008 ensures that the type of "x" is of sort "foo" (but not necessarily a
  5009 type variable);
  5010 
  5011 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  5012 control output of nested => (types); the default behavior is
  5013 "type_brackets";
  5014 
  5015 * Pure/syntax: builtin parse translation for "_constify" turns valued
  5016 tokens into AST constants;
  5017 
  5018 * Pure/syntax: prefer later declarations of translations and print
  5019 translation functions; potential INCOMPATIBILITY: need to reverse
  5020 multiple declarations for same syntax element constant;
  5021 
  5022 * Pure/show_hyps reset by default (in accordance to existing Isar
  5023 practice);
  5024 
  5025 * Provers/classical: renamed addaltern to addafter, addSaltern to
  5026 addSafter;
  5027 
  5028 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  5029 as well;
  5030 
  5031 * system: tested support for MacOS X; should be able to get Isabelle +
  5032 Proof General to work in a plain Terminal after installing Poly/ML
  5033 (e.g. from the Isabelle distribution area) and GNU bash alone
  5034 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  5035 support requires further installations, e.g. from
  5036 http://fink.sourceforge.net/);
  5037 
  5038 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  5039 
  5040 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  5041 of 40 MB), cf. ML_OPTIONS;
  5042 
  5043 * system: Proof General keywords specification is now part of the
  5044 Isabelle distribution (see etc/isar-keywords.el);
  5045 
  5046 * system: support for persistent Proof General sessions (refrain from
  5047 outdating all loaded theories on startup); user may create writable
  5048 logic images like this: ``isabelle -q HOL Test'';
  5049 
  5050 * system: smart selection of Isabelle process versus Isabelle
  5051 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  5052 run both "isabelle" and "Isabelle" even if file names are badly
  5053 damaged (executable inspects the case of the first letter of its own
  5054 name); added separate "isabelle-process" and "isabelle-interface";
  5055 
  5056 * system: refrain from any attempt at filtering input streams; no
  5057 longer support ``8bit'' encoding of old isabelle font, instead proper
  5058 iso-latin characters may now be used; the related isatools
  5059 "symbolinput" and "nonascii" have disappeared as well;
  5060 
  5061 * system: removed old "xterm" interface (the print modes "xterm" and
  5062 "xterm_color" are still available for direct use in a suitable
  5063 terminal);
  5064 
  5065 
  5066 
  5067 New in Isabelle99-2 (February 2001)
  5068 -----------------------------------
  5069 
  5070 *** Overview of INCOMPATIBILITIES ***
  5071 
  5072 * HOL: please note that theories in the Library and elsewhere often use the
  5073 new-style (Isar) format; to refer to their theorems in an ML script you must
  5074 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  5075 
  5076 * HOL: inductive package no longer splits induction rule aggressively,
  5077 but only as far as specified by the introductions given; the old
  5078 format may be recovered via ML function complete_split_rule or attribute
  5079 'split_rule (complete)';
  5080 
  5081 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  5082 gfp_Tarski to gfp_unfold;
  5083 
  5084 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  5085 
  5086 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  5087 relation); infix "^^" has been renamed "``"; infix "``" has been
  5088 renamed "`"; "univalent" has been renamed "single_valued";
  5089 
  5090 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  5091 operation;
  5092 
  5093 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  5094 
  5095 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  5096 
  5097 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  5098 consequence, it is no longer monotonic wrt. the local goal context
  5099 (which is now passed through the inductive cases);
  5100 
  5101 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  5102 \<gg> to \<ggreater>;
  5103 
  5104 
  5105 *** Document preparation ***
  5106 
  5107 * \isabellestyle{NAME} selects version of Isabelle output (currently
  5108 available: are "it" for near math-mode best-style output, "sl" for
  5109 slanted text style, and "tt" for plain type-writer; if no
  5110 \isabellestyle command is given, output is according to slanted
  5111 type-writer);
  5112 
  5113 * support sub/super scripts (for single symbols only), input syntax is
  5114 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  5115 
  5116 * some more standard symbols; see Appendix A of the system manual for
  5117 the complete list of symbols defined in isabellesym.sty;
  5118 
  5119 * improved isabelle style files; more abstract symbol implementation
  5120 (should now use \isamath{...} and \isatext{...} in custom symbol
  5121 definitions);
  5122 
  5123 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  5124 state; Note that presentation of goal states does not conform to
  5125 actual human-readable proof documents.  Please do not include goal
  5126 states into document output unless you really know what you are doing!
  5127 
  5128 * proper indentation of antiquoted output with proportional LaTeX
  5129 fonts;
  5130 
  5131 * no_document ML operator temporarily disables LaTeX document
  5132 generation;
  5133 
  5134 * isatool unsymbolize tunes sources for plain ASCII communication;
  5135 
  5136 
  5137 *** Isar ***
  5138 
  5139 * Pure: Isar now suffers initial goal statements to contain unbound
  5140 schematic variables (this does not conform to actual readable proof
  5141 documents, due to unpredictable outcome and non-compositional proof
  5142 checking); users who know what they are doing may use schematic goals
  5143 for Prolog-style synthesis of proven results;
  5144 
  5145 * Pure: assumption method (an implicit finishing) now handles actual
  5146 rules as well;
  5147 
  5148 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  5149 initial goal, declare "that" only as Pure intro (only for single
  5150 steps); the "that" rule assumption may now be involved in implicit
  5151 finishing, thus ".." becomes a feasible for trivial obtains;
  5152 
  5153 * Pure: default proof step now includes 'intro_classes'; thus trivial
  5154 instance proofs may be performed by "..";
  5155 
  5156 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5157 statements as well;
  5158 
  5159 * Pure: more robust selection of calculational rules;
  5160 
  5161 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5162 rule (as well as the assumption rule);
  5163 
  5164 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5165 lemmas, using the graph browser tool;
  5166 
  5167 * Pure: predict failure of "show" in interactive mode;
  5168 
  5169 * Pure: 'thms_containing' now takes actual terms as arguments;
  5170 
  5171 * HOL: improved method 'induct' --- now handles non-atomic goals
  5172 (potential INCOMPATIBILITY); tuned error handling;
  5173 
  5174 * HOL: cases and induct rules now provide explicit hints about the
  5175 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5176 any remaining facts are inserted into the goal verbatim;
  5177 
  5178 * HOL: local contexts (aka cases) may now contain term bindings as
  5179 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5180 the result to be shown in each case;
  5181 
  5182 * HOL: added 'recdef_tc' command;
  5183 
  5184 * isatool convert assists in eliminating legacy ML scripts;
  5185 
  5186 
  5187 *** HOL ***
  5188 
  5189 * HOL/Library: a collection of generic theories to be used together
  5190 with main HOL; the theory loader path already includes this directory
  5191 by default; the following existing theories have been moved here:
  5192 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5193 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5194 
  5195 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5196 modelling and verification task performed in Isabelle/HOL +
  5197 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5198 
  5199 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5200 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5201 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5202 'domain', this makes the theory consistent with mathematical
  5203 literature;
  5204 
  5205 * HOL basics: added overloaded operations "inverse" and "divide"
  5206 (infix "/"), syntax for generic "abs" operation, generic summation
  5207 operator \<Sum>;
  5208 
  5209 * HOL/typedef: simplified package, provide more useful rules (see also
  5210 HOL/subset.thy);
  5211 
  5212 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5213 now expressed as a proper nested rule (old-style tactic scripts may
  5214 require atomize_strip_tac to cope with non-atomic premises);
  5215 
  5216 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5217 to "split_conv" (old name still available for compatibility);
  5218 
  5219 * HOL: improved concrete syntax for strings (e.g. allows translation
  5220 rules with string literals);
  5221 
  5222 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5223  and Fleuriot's mechanization of analysis, including the transcendental
  5224  functions for the reals;
  5225 
  5226 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5227 
  5228 
  5229 *** CTT ***
  5230 
  5231 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5232 "lam" is displayed as TWO lambda-symbols
  5233 
  5234 * CTT: theory Main now available, containing everything (that is, Bool
  5235 and Arith);
  5236 
  5237 
  5238 *** General ***
  5239 
  5240 * Pure: the Simplifier has been implemented properly as a derived rule
  5241 outside of the actual kernel (at last!); the overall performance
  5242 penalty in practical applications is about 50%, while reliability of
  5243 the Isabelle inference kernel has been greatly improved;
  5244 
  5245 * print modes "brackets" and "no_brackets" control output of nested =>
  5246 (types) and ==> (props); the default behaviour is "brackets";
  5247 
  5248 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5249 as assumptions as well;
  5250 
  5251 * system: support Poly/ML 4.0;
  5252 
  5253 * system: isatool install handles KDE version 1 or 2;
  5254 
  5255 
  5256 
  5257 New in Isabelle99-1 (October 2000)
  5258 ----------------------------------
  5259 
  5260 *** Overview of INCOMPATIBILITIES ***
  5261 
  5262 * HOL: simplification of natural numbers is much changed; to partly
  5263 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5264 issue the following ML commands:
  5265 
  5266   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5267   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5268 
  5269 * HOL: simplification no longer dives into case-expressions; this is
  5270 controlled by "t.weak_case_cong" for each datatype t;
  5271 
  5272 * HOL: nat_less_induct renamed to less_induct;
  5273 
  5274 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5275 fixsome to patch .thy and .ML sources automatically;
  5276 
  5277   select_equality  -> some_equality
  5278   select_eq_Ex     -> some_eq_ex
  5279   selectI2EX       -> someI2_ex
  5280   selectI2         -> someI2
  5281   selectI          -> someI
  5282   select1_equality -> some1_equality
  5283   Eps_sym_eq       -> some_sym_eq_trivial
  5284   Eps_eq           -> some_eq_trivial
  5285 
  5286 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5287 
  5288 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5289 instead);
  5290 
  5291 * HOL: the recursion equations generated by 'recdef' are now called
  5292 f.simps instead of f.rules;
  5293 
  5294 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5295 
  5296 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5297 sometimes be needed;
  5298 
  5299 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5300 
  5301 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5302 
  5303 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5304 product is now "<*>" instead of "Times"; the lexicographic product is
  5305 now "<*lex*>" instead of "**";
  5306 
  5307 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5308 of main HOL, but was unused); better use HOL's datatype package;
  5309 
  5310 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5311 the old syntax may be recovered as follows:
  5312 
  5313   syntax (symbols)
  5314     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5315       (infixl "\\<oplus>" 100)
  5316 
  5317 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5318 
  5319 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5320 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5321 internally;
  5322 
  5323 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5324 changed from A/r to A//r;
  5325 
  5326 * ZF: new treatment of arithmetic (nat & int) may break some old
  5327 proofs;
  5328 
  5329 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5330 rulify -> rule_format, elimify -> elim_format, ...);
  5331 
  5332 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5333 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5334 should have to change intro!! to intro? only); replaced "delrule" by
  5335 "rule del";
  5336 
  5337 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5338 
  5339 * Provers: strengthened force_tac by using new first_best_tac;
  5340 
  5341 * LaTeX document preparation: several changes of isabelle.sty (see
  5342 lib/texinputs);
  5343 
  5344 
  5345 *** Document preparation ***
  5346 
  5347 * formal comments (text blocks etc.) in new-style theories may now
  5348 contain antiquotations of thm/prop/term/typ/text to be presented
  5349 according to latex print mode; concrete syntax is like this:
  5350 @{term[show_types] "f(x) = a + x"};
  5351 
  5352 * isatool mkdir provides easy setup of Isabelle session directories,
  5353 including proper document sources;
  5354 
  5355 * generated LaTeX sources are now deleted after successful run
  5356 (isatool document -c); may retain a copy somewhere else via -D option
  5357 of isatool usedir;
  5358 
  5359 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5360 style files, achieving self-contained LaTeX sources and simplifying
  5361 LaTeX debugging;
  5362 
  5363 * old-style theories now produce (crude) LaTeX output as well;
  5364 
  5365 * browser info session directories are now self-contained (may be put
  5366 on WWW server seperately); improved graphs of nested sessions; removed
  5367 graph for 'all sessions';
  5368 
  5369 * several improvements in isabelle style files; \isabellestyle{it}
  5370 produces fake math mode output; \isamarkupheader is now \section by
  5371 default; see lib/texinputs/isabelle.sty etc.;
  5372 
  5373 
  5374 *** Isar ***
  5375 
  5376 * Isar/Pure: local results and corresponding term bindings are now
  5377 subject to Hindley-Milner polymorphism (similar to ML); this
  5378 accommodates incremental type-inference very nicely;
  5379 
  5380 * Isar/Pure: new derived language element 'obtain' supports
  5381 generalized existence reasoning;
  5382 
  5383 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5384 support accumulation of results, without applying any rules yet;
  5385 useful to collect intermediate results without explicit name
  5386 references, and for use with transitivity rules with more than 2
  5387 premises;
  5388 
  5389 * Isar/Pure: scalable support for case-analysis type proofs: new
  5390 'case' language element refers to local contexts symbolically, as
  5391 produced by certain proof methods; internally, case names are attached
  5392 to theorems as "tags";
  5393 
  5394 * Isar/Pure: theory command 'hide' removes declarations from
  5395 class/type/const name spaces;
  5396 
  5397 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5398 indicate potential overloading;
  5399 
  5400 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5401 
  5402 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5403 "{a,b,c}" instead of {a,b,c};
  5404 
  5405 * Isar/Pure now provides its own version of intro/elim/dest
  5406 attributes; useful for building new logics, but beware of confusion
  5407 with the version in Provers/classical;
  5408 
  5409 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5410 case name 'antecedent';
  5411 
  5412 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5413 to the current context is now done automatically);
  5414 
  5415 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5416 for definining proof methods in ML;
  5417 
  5418 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5419 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5420 most cases, one should have to change intro!! to intro? only);
  5421 replaced "delrule" by "rule del";
  5422 
  5423 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5424 'symmetric' attribute (the latter supercedes [RS sym]);
  5425 
  5426 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5427 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5428 well (including splits);
  5429 
  5430 * Isar/Provers: Simplifier and Classical methods now support all kind
  5431 of modifiers used in the past, including 'cong', 'iff', etc.
  5432 
  5433 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5434 of Simplifier and Classical reasoner);
  5435 
  5436 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5437 now support named cases; major packages (inductive, datatype, primrec,
  5438 recdef) support case names and properly name parameters;
  5439 
  5440 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5441 monotonicity conditions are extracted to be proven at end of
  5442 calculations;
  5443 
  5444 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5445 method anyway;
  5446 
  5447 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5448 split_if split_if_asm; datatype package provides theorems foo.splits =
  5449 foo.split foo.split_asm for each datatype;
  5450 
  5451 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5452 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5453 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5454 use "(cases (simplified))" method in proper proof texts);
  5455 
  5456 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5457 
  5458 * Isar: names of theorems etc. may be natural numbers as well;
  5459 
  5460 * Isar: 'pr' command: optional arguments for goals_limit and
  5461 ProofContext.prems_limit; no longer prints theory contexts, but only
  5462 proof states;
  5463 
  5464 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5465 additional print modes to be specified; e.g. "pr(latex)" will print
  5466 proof state according to the Isabelle LaTeX style;
  5467 
  5468 * Isar: improved support for emulating tactic scripts, including proof
  5469 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5470 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5471 (for HOL datatypes);
  5472 
  5473 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5474 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5475 'proof method scripts' have to be in depth-first order;
  5476 
  5477 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5478 
  5479 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5480 should instead use individual commands for printing items
  5481 (print_commands, print_methods etc.);
  5482 
  5483 * Isar: added 'nothing' --- the empty list of theorems;
  5484 
  5485 
  5486 *** HOL ***
  5487 
  5488 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5489 corresponding virtual machine and a specification of its bytecode
  5490 verifier and a lightweight bytecode verifier, including proofs of
  5491 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5492 Cornelia Pusch (see also the homepage of project Bali at
  5493 http://isabelle.in.tum.de/Bali/);
  5494 
  5495 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5496 Clemens Ballarin;
  5497 
  5498 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5499 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5500 Rasmussen;
  5501 
  5502 * HOL/Lattice: fundamental concepts of lattice theory and order
  5503 structures, including duals, properties of bounds versus algebraic
  5504 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5505 Theorem for complete lattices etc.; may also serve as a demonstration
  5506 for abstract algebraic reasoning using axiomatic type classes, and
  5507 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5508 
  5509 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5510 von Oheimb;
  5511 
  5512 * HOL/IMPP: extension of IMP with local variables and mutually
  5513 recursive procedures, by David von Oheimb;
  5514 
  5515 * HOL/Lambda: converted into new-style theory and document;
  5516 
  5517 * HOL/ex/Multiquote: example of multiple nested quotations and
  5518 anti-quotations -- basically a generalized version of de-Bruijn
  5519 representation; very useful in avoiding lifting of operations;
  5520 
  5521 * HOL/record: added general record equality rule to simpset; fixed
  5522 select-update simplification procedure to handle extended records as
  5523 well; admit "r" as field name;
  5524 
  5525 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5526 other numeric types and also as the identity of groups, rings, etc.;
  5527 
  5528 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5529 Types nat and int belong to this axclass;
  5530 
  5531 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5532    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5533    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5534   two terms #m*u and #n*u are replaced by #(m+n)*u
  5535     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5536   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5537     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5538 
  5539 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5540 powerful prover for predicate logic but knows nothing of clasets; see
  5541 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5542 
  5543 * HOL: new version of "case_tac" subsumes both boolean case split and
  5544 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5545 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5546 
  5547 * HOL: simplification no longer dives into case-expressions: only the
  5548 selector expression is simplified, but not the remaining arms; to
  5549 enable full simplification of case-expressions for datatype t, you may
  5550 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5551 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5552 
  5553 * HOL/recdef: the recursion equations generated by 'recdef' for
  5554 function 'f' are now called f.simps instead of f.rules; if all
  5555 termination conditions are proved automatically, these simplification
  5556 rules are added to the simpset, as in primrec; rules may be named
  5557 individually as well, resulting in a separate list of theorems for
  5558 each equation;
  5559 
  5560 * HOL/While is a new theory that provides a while-combinator. It
  5561 permits the definition of tail-recursive functions without the
  5562 provision of a termination measure. The latter is necessary once the
  5563 invariant proof rule for while is applied.
  5564 
  5565 * HOL: new (overloaded) notation for the set of elements below/above
  5566 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5567 
  5568 * HOL: theorems impI, allI, ballI bound as "strip";
  5569 
  5570 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5571 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5572 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5573 
  5574 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5575 
  5576 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5577 main HOL, but was unused);
  5578 
  5579 * HOL: fewer consts declared as global (e.g. have to refer to
  5580 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5581 
  5582 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5583 in case of overlap with user translations (e.g. judgements over
  5584 tuples); (note that the underlying logical represenation is still
  5585 bogus);
  5586 
  5587 
  5588 *** ZF ***
  5589 
  5590 * ZF: simplification automatically cancels common terms in arithmetic
  5591 expressions over nat and int;
  5592 
  5593 * ZF: new treatment of nat to minimize type-checking: all operators
  5594 coerce their operands to a natural number using the function natify,
  5595 making the algebraic laws unconditional;
  5596 
  5597 * ZF: as above, for int: operators coerce their operands to an integer
  5598 using the function intify;
  5599 
  5600 * ZF: the integer library now contains many of the usual laws for the
  5601 orderings, including $<=, and monotonicity laws for $+ and $*;
  5602 
  5603 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5604 simplification;
  5605 
  5606 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5607 to the simplifier and classical reasoner simultaneously;
  5608 
  5609 
  5610 *** General ***
  5611 
  5612 * Provers: blast_tac now handles actual object-logic rules as
  5613 assumptions; note that auto_tac uses blast_tac internally as well;
  5614 
  5615 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5616 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5617 
  5618 * Provers: delrules now handles destruct rules as well (no longer need
  5619 explicit make_elim);
  5620 
  5621 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5622   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5623 use instead the strong form,
  5624   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5625 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5626 from destruct-rules;
  5627 
  5628 * Provers: Simplifier.easy_setup provides a fast path to basic
  5629 Simplifier setup for new object-logics;
  5630 
  5631 * Pure: AST translation rules no longer require constant head on LHS;
  5632 
  5633 * Pure: improved name spaces: ambiguous output is qualified; support
  5634 for hiding of names;
  5635 
  5636 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5637 XSYMBOL_HOME; no longer need to do manual configuration in most
  5638 situations;
  5639 
  5640 * system: compression of ML heaps images may now be controlled via -c
  5641 option of isabelle and isatool usedir (currently only observed by
  5642 Poly/ML);
  5643 
  5644 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5645 useful for remote X11);
  5646 
  5647 * system: provide TAGS file for Isabelle sources;
  5648 
  5649 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5650 order;
  5651 
  5652 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5653 timing flag supersedes proof_timing and Toplevel.trace;
  5654 
  5655 * ML: new combinators |>> and |>>> for incremental transformations
  5656 with secondary results (e.g. certain theory extensions):
  5657 
  5658 * ML: PureThy.add_defs gets additional argument to indicate potential
  5659 overloading (usually false);
  5660 
  5661 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5662 results;
  5663 
  5664 
  5665 
  5666 New in Isabelle99 (October 1999)
  5667 --------------------------------
  5668 
  5669 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5670 
  5671 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5672 are no longer simplified.  (This allows the simplifier to unfold recursive
  5673 functional programs.)  To restore the old behaviour, declare
  5674 
  5675     Delcongs [if_weak_cong];
  5676 
  5677 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5678 complement;
  5679 
  5680 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5681 
  5682 * HOL/datatype: mutual_induct_tac no longer exists --
  5683   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5684 
  5685 * HOL/typedef: fixed type inference for representing set; type
  5686 arguments now have to occur explicitly on the rhs as type constraints;
  5687 
  5688 * ZF: The con_defs part of an inductive definition may no longer refer
  5689 to constants declared in the same theory;
  5690 
  5691 * HOL, ZF: the function mk_cases, generated by the inductive
  5692 definition package, has lost an argument.  To simplify its result, it
  5693 uses the default simpset instead of a supplied list of theorems.
  5694 
  5695 * HOL/List: the constructors of type list are now Nil and Cons;
  5696 
  5697 * Simplifier: the type of the infix ML functions
  5698         setSSolver addSSolver setSolver addSolver
  5699 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5700 for packaging solvers. A solver is created via
  5701         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5702 where the string argument is only a comment.
  5703 
  5704 
  5705 *** Proof tools ***
  5706 
  5707 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5708 decision procedure for linear arithmetic. Currently it is used for
  5709 types `nat', `int', and `real' in HOL (see below); it can, should and
  5710 will be instantiated for other types and logics as well.
  5711 
  5712 * The simplifier now accepts rewrite rules with flexible heads, eg
  5713      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5714   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5715   matching.
  5716 
  5717 
  5718 *** General ***
  5719 
  5720 * New Isabelle/Isar subsystem provides an alternative to traditional
  5721 tactical theorem proving; together with the ProofGeneral/isar user
  5722 interface it offers an interactive environment for developing human
  5723 readable proof documents (Isar == Intelligible semi-automated
  5724 reasoning); for further information see isatool doc isar-ref,
  5725 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5726 
  5727 * improved and simplified presentation of theories: better HTML markup
  5728 (including colors), graph views in several sizes; isatool usedir now
  5729 provides a proper interface for user theories (via -P option); actual
  5730 document preparation based on (PDF)LaTeX is available as well (for
  5731 new-style theories only); see isatool doc system for more information;
  5732 
  5733 * native support for Proof General, both for classic Isabelle and
  5734 Isabelle/Isar;
  5735 
  5736 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5737 using the graph browser tool;
  5738 
  5739 * Isabelle manuals now also available as PDF;
  5740 
  5741 * theory loader rewritten from scratch (may not be fully
  5742 bug-compatible); old loadpath variable has been replaced by show_path,
  5743 add_path, del_path, reset_path functions; new operations such as
  5744 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5745 isatool doc ref);
  5746 
  5747 * improved isatool install: option -k creates KDE application icon,
  5748 option -p DIR installs standalone binaries;
  5749 
  5750 * added ML_PLATFORM setting (useful for cross-platform installations);
  5751 more robust handling of platform specific ML images for SML/NJ;
  5752 
  5753 * the settings environment is now statically scoped, i.e. it is never
  5754 created again in sub-processes invoked from isabelle, isatool, or
  5755 Isabelle;
  5756 
  5757 * path element specification '~~' refers to '$ISABELLE_HOME';
  5758 
  5759 * in locales, the "assumes" and "defines" parts may be omitted if
  5760 empty;
  5761 
  5762 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5763 long arrows);
  5764 
  5765 * new print_mode "HTML";
  5766 
  5767 * new flag show_tags controls display of tags of theorems (which are
  5768 basically just comments that may be attached by some tools);
  5769 
  5770 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5771 mode and goal output format:
  5772 
  5773 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5774 244c244
  5775 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5776 ---
  5777 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5778 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5779 181c181
  5780 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5781 ---
  5782 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5783 
  5784 * function bind_thms stores lists of theorems (cf. bind_thm);
  5785 
  5786 * new shorthand tactics ftac, eatac, datac, fatac;
  5787 
  5788 * qed (and friends) now accept "" as result name; in that case the
  5789 theorem is not stored, but proper checks and presentation of the
  5790 result still apply;
  5791 
  5792 * theorem database now also indexes constants "Trueprop", "all",
  5793 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5794 
  5795 
  5796 *** HOL ***
  5797 
  5798 ** HOL arithmetic **
  5799 
  5800 * There are now decision procedures for linear arithmetic over nat and
  5801 int:
  5802 
  5803 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5804 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5805 are treated as atomic; subformulae not involving type `nat' or `int'
  5806 are ignored; quantified subformulae are ignored unless they are
  5807 positive universal or negative existential. The tactic has to be
  5808 invoked by hand and can be a little bit slow. In particular, the
  5809 running time is exponential in the number of occurrences of `min' and
  5810 `max', and `-' on `nat'.
  5811 
  5812 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5813 (negated) (in)equalities among the premises and the conclusion into
  5814 account (i.e. no compound formulae) and does not know about `min' and
  5815 `max', and `-' on `nat'. It is fast and is used automatically by the
  5816 simplifier.
  5817 
  5818 NB: At the moment, these decision procedures do not cope with mixed
  5819 nat/int formulae where the two parts interact, such as `m < n ==>
  5820 int(m) < int(n)'.
  5821 
  5822 * HOL/Numeral provides a generic theory of numerals (encoded
  5823 efficiently as bit strings); setup for types nat/int/real is in place;
  5824 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5825 int, existing theories and proof scripts may require a few additional
  5826 type constraints;
  5827 
  5828 * integer division and remainder can now be performed on constant
  5829 arguments;
  5830 
  5831 * many properties of integer multiplication, division and remainder
  5832 are now available;
  5833 
  5834 * An interface to the Stanford Validity Checker (SVC) is available through the
  5835 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5836 are proved automatically.  SVC must be installed separately, and its results
  5837 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5838 invocation of the underlying oracle).  For SVC see
  5839   http://verify.stanford.edu/SVC
  5840 
  5841 * IsaMakefile: the HOL-Real target now builds an actual image;
  5842 
  5843 
  5844 ** HOL misc **
  5845 
  5846 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5847 (in Isabelle/Isar) -- by Gertrud Bauer;
  5848 
  5849 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5850 analysis for assembly languages with subtypes;
  5851 
  5852 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5853 -- avoids syntactic ambiguities and treats state, transition, and
  5854 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5855 changed syntax and (many) tactics;
  5856 
  5857 * HOL/inductive: Now also handles more general introduction rules such
  5858   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5859   theorems are now maintained within the theory (maintained via the
  5860   "mono" attribute);
  5861 
  5862 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5863   (using function types) such as
  5864 
  5865   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5866 
  5867 * HOL/record: record_simproc (part of the default simpset) takes care
  5868 of selectors applied to updated records; record_split_tac is no longer
  5869 part of the default claset; update_defs may now be removed from the
  5870 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5871 
  5872   claset_ref () := claset() addSWrapper record_split_wrapper;
  5873   Delsimprocs [record_simproc]
  5874 
  5875 * HOL/typedef: fixed type inference for representing set; type
  5876 arguments now have to occur explicitly on the rhs as type constraints;
  5877 
  5878 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5879 names rather than an ML expression;
  5880 
  5881 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5882 supplied later.  Program schemes can be defined, such as
  5883     "While B C s = (if B s then While B C (C s) else s)"
  5884 where the well-founded relation can be chosen after B and C have been given.
  5885 
  5886 * HOL/List: the constructors of type list are now Nil and Cons;
  5887 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5888 course, ML tools referring to List.list.op # etc. have to be adapted;
  5889 
  5890 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5891 disabled by default; run isabelle with option -m HOL to get back to
  5892 the original Gordon/HOL-style output;
  5893 
  5894 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5895 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5896 
  5897 * HOL basic syntax simplified (more orthogonal): all variants of
  5898 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5899 Eps operator is provided as well: "SOME x. P[x]";
  5900 
  5901 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5902 
  5903 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5904 thus available for user theories;
  5905 
  5906 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5907 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5908 time;
  5909 
  5910 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5911 several times and then mp;
  5912 
  5913 
  5914 *** LK ***
  5915 
  5916 * the notation <<...>> is now available as a notation for sequences of
  5917 formulas;
  5918 
  5919 * the simplifier is now installed
  5920 
  5921 * the axiom system has been generalized (thanks to Soren Heilmann)
  5922 
  5923 * the classical reasoner now has a default rule database
  5924 
  5925 
  5926 *** ZF ***
  5927 
  5928 * new primrec section allows primitive recursive functions to be given
  5929 directly (as in HOL) over datatypes and the natural numbers;
  5930 
  5931 * new tactics induct_tac and exhaust_tac for induction (or case
  5932 analysis) over datatypes and the natural numbers;
  5933 
  5934 * the datatype declaration of type T now defines the recursor T_rec;
  5935 
  5936 * simplification automatically does freeness reasoning for datatype
  5937 constructors;
  5938 
  5939 * automatic type-inference, with AddTCs command to insert new
  5940 type-checking rules;
  5941 
  5942 * datatype introduction rules are now added as Safe Introduction rules
  5943 to the claset;
  5944 
  5945 * the syntax "if P then x else y" is now available in addition to
  5946 if(P,x,y);
  5947 
  5948 
  5949 *** Internal programming interfaces ***
  5950 
  5951 * tuned simplifier trace output; new flag debug_simp;
  5952 
  5953 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5954 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5955 
  5956 * AxClass.axclass_tac lost the theory argument;
  5957 
  5958 * tuned current_goals_markers semantics: begin / end goal avoids
  5959 printing empty lines;
  5960 
  5961 * removed prs and prs_fn hook, which was broken because it did not
  5962 include \n in its semantics, forcing writeln to add one
  5963 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5964 string -> unit if you really want to output text without newline;
  5965 
  5966 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5967 plain output, interface builders may have to enable 'isabelle_font'
  5968 mode to get Isabelle font glyphs as before;
  5969 
  5970 * refined token_translation interface; INCOMPATIBILITY: output length
  5971 now of type real instead of int;
  5972 
  5973 * theory loader actions may be traced via new ThyInfo.add_hook
  5974 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5975 your own database of information attached to *whole* theories -- as
  5976 opposed to intra-theory data slots offered via TheoryDataFun;
  5977 
  5978 * proper handling of dangling sort hypotheses (at last!);
  5979 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5980 extra sort hypotheses that can be witnessed from the type signature;
  5981 the force_strip_shyps flag is gone, any remaining shyps are simply
  5982 left in the theorem (with a warning issued by strip_shyps_warning);
  5983 
  5984 
  5985 
  5986 New in Isabelle98-1 (October 1998)
  5987 ----------------------------------
  5988 
  5989 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5990 
  5991 * several changes of automated proof tools;
  5992 
  5993 * HOL: major changes to the inductive and datatype packages, including
  5994 some minor incompatibilities of theory syntax;
  5995 
  5996 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5997 called `inj_on';
  5998 
  5999 * HOL: removed duplicate thms in Arith:
  6000   less_imp_add_less  should be replaced by  trans_less_add1
  6001   le_imp_add_le      should be replaced by  trans_le_add1
  6002 
  6003 * HOL: unary minus is now overloaded (new type constraints may be
  6004 required);
  6005 
  6006 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  6007 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  6008 now taken as an integer constant.
  6009 
  6010 * Pure: ML function 'theory_of' renamed to 'theory';
  6011 
  6012 
  6013 *** Proof tools ***
  6014 
  6015 * Simplifier:
  6016   1. Asm_full_simp_tac is now more aggressive.
  6017      1. It will sometimes reorient premises if that increases their power to
  6018         simplify.
  6019      2. It does no longer proceed strictly from left to right but may also
  6020         rotate premises to achieve further simplification.
  6021      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  6022      old Asm_full_simp_tac in that it does not rotate premises.
  6023   2. The simplifier now knows a little bit about nat-arithmetic.
  6024 
  6025 * Classical reasoner: wrapper mechanism for the classical reasoner now
  6026 allows for selected deletion of wrappers, by introduction of names for
  6027 wrapper functionals.  This implies that addbefore, addSbefore,
  6028 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  6029 and that adding two tactics with the same name overwrites the first
  6030 one (emitting a warning).
  6031   type wrapper = (int -> tactic) -> (int -> tactic)
  6032   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  6033   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  6034   delWrapper, delSWrapper: claset *  string            -> claset
  6035   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  6036 
  6037 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  6038 semantics; addbefore now affects only the unsafe part of step_tac
  6039 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  6040 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  6041 by Force_tac;
  6042 
  6043 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  6044 compWrapper; added safe wrapper (and access functions for it);
  6045 
  6046 * HOL/split_all_tac is now much faster and fails if there is nothing
  6047 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  6048 and the names of the automatically generated variables have changed.
  6049 split_all_tac has moved within claset() from unsafe wrappers to safe
  6050 wrappers, which means that !!-bound variables are split much more
  6051 aggressively, and safe_tac and clarify_tac now split such variables.
  6052 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  6053 Note: the same holds for record_split_tac, which does the job of
  6054 split_all_tac for record fields.
  6055 
  6056 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  6057 permanently to the default simpset using Addsplits just like
  6058 Addsimps. They can be removed via Delsplits just like
  6059 Delsimps. Lower-case versions are also available.
  6060 
  6061 * HOL/Simplifier: The rule split_if is now part of the default
  6062 simpset. This means that the simplifier will eliminate all occurrences
  6063 of if-then-else in the conclusion of a goal. To prevent this, you can
  6064 either remove split_if completely from the default simpset by
  6065 `Delsplits [split_if]' or remove it in a specific call of the
  6066 simplifier using `... delsplits [split_if]'.  You can also add/delete
  6067 other case splitting rules to/from the default simpset: every datatype
  6068 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  6069 t is the name of the datatype).
  6070 
  6071 * Classical reasoner / Simplifier combination: new force_tac (and
  6072 derivatives Force_tac, force) combines rewriting and classical
  6073 reasoning (and whatever other tools) similarly to auto_tac, but is
  6074 aimed to solve the given subgoal completely.
  6075 
  6076 
  6077 *** General ***
  6078 
  6079 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  6080 and `goalw': the theory is no longer needed as an explicit argument -
  6081 the current theory context is used; assumptions are no longer returned
  6082 at the ML-level unless one of them starts with ==> or !!; it is
  6083 recommended to convert to these new commands using isatool fixgoal
  6084 (backup your sources first!);
  6085 
  6086 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  6087 the current theory context, and 'theory' to lookup stored theories;
  6088 
  6089 * new theory section 'locale' for declaring constants, assumptions and
  6090 definitions that have local scope;
  6091 
  6092 * new theory section 'nonterminals' for purely syntactic types;
  6093 
  6094 * new theory section 'setup' for generic ML setup functions
  6095 (e.g. package initialization);
  6096 
  6097 * the distribution now includes Isabelle icons: see
  6098 lib/logo/isabelle-{small,tiny}.xpm;
  6099 
  6100 * isatool install - install binaries with absolute references to
  6101 ISABELLE_HOME/bin;
  6102 
  6103 * isatool logo -- create instances of the Isabelle logo (as EPS);
  6104 
  6105 * print mode 'emacs' reserved for Isamode;
  6106 
  6107 * support multiple print (ast) translations per constant name;
  6108 
  6109 * theorems involving oracles are now printed with a suffixed [!];
  6110 
  6111 
  6112 *** HOL ***
  6113 
  6114 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  6115 
  6116 * HOL/inductive package reorganized and improved: now supports mutual
  6117 definitions such as
  6118 
  6119   inductive EVEN ODD
  6120     intrs
  6121       null "0 : EVEN"
  6122       oddI "n : EVEN ==> Suc n : ODD"
  6123       evenI "n : ODD ==> Suc n : EVEN"
  6124 
  6125 new theorem list "elims" contains an elimination rule for each of the
  6126 recursive sets; inductive definitions now handle disjunctive premises
  6127 correctly (also ZF);
  6128 
  6129 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  6130 "mutual_induct" no longer exists - the induction rule is always
  6131 contained in "induct";
  6132 
  6133 
  6134 * HOL/datatype package re-implemented and greatly improved: now
  6135 supports mutually recursive datatypes such as
  6136 
  6137   datatype
  6138     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  6139             | SUM ('a aexp) ('a aexp)
  6140             | DIFF ('a aexp) ('a aexp)
  6141             | NUM 'a
  6142   and
  6143     'a bexp = LESS ('a aexp) ('a aexp)
  6144             | AND ('a bexp) ('a bexp)
  6145             | OR ('a bexp) ('a bexp)
  6146 
  6147 as well as indirectly recursive datatypes such as
  6148 
  6149   datatype
  6150     ('a, 'b) term = Var 'a
  6151                   | App 'b ((('a, 'b) term) list)
  6152 
  6153 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  6154 induction on mutually / indirectly recursive datatypes.
  6155 
  6156 Primrec equations are now stored in theory and can be accessed via
  6157 <function_name>.simps.
  6158 
  6159 INCOMPATIBILITIES:
  6160 
  6161   - Theories using datatypes must now have theory Datatype as an
  6162     ancestor.
  6163   - The specific <typename>.induct_tac no longer exists - use the
  6164     generic induct_tac instead.
  6165   - natE has been renamed to nat.exhaust - use exhaust_tac
  6166     instead of res_inst_tac ... natE. Note that the variable
  6167     names in nat.exhaust differ from the names in natE, this
  6168     may cause some "fragile" proofs to fail.
  6169   - The theorems split_<typename>_case and split_<typename>_case_asm
  6170     have been renamed to <typename>.split and <typename>.split_asm.
  6171   - Since default sorts of type variables are now handled correctly,
  6172     some datatype definitions may have to be annotated with explicit
  6173     sort constraints.
  6174   - Primrec definitions no longer require function name and type
  6175     of recursive argument.
  6176 
  6177 Consider using isatool fixdatatype to adapt your theories and proof
  6178 scripts to the new package (backup your sources first!).
  6179 
  6180 
  6181 * HOL/record package: considerably improved implementation; now
  6182 includes concrete syntax for record types, terms, updates; theorems
  6183 for surjective pairing and splitting !!-bound record variables; proof
  6184 support is as follows:
  6185 
  6186   1) standard conversions (selectors or updates applied to record
  6187 constructor terms) are part of the standard simpset;
  6188 
  6189   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  6190 made part of standard simpset and claset via addIffs;
  6191 
  6192   3) a tactic for record field splitting (record_split_tac) is part of
  6193 the standard claset (addSWrapper);
  6194 
  6195 To get a better idea about these rules you may retrieve them via
  6196 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  6197 the name of your record type.
  6198 
  6199 The split tactic 3) conceptually simplifies by the following rule:
  6200 
  6201   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  6202 
  6203 Thus any record variable that is bound by meta-all will automatically
  6204 blow up into some record constructor term, consequently the
  6205 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  6206 solve record problems automatically.
  6207 
  6208 
  6209 * reorganized the main HOL image: HOL/Integ and String loaded by
  6210 default; theory Main includes everything;
  6211 
  6212 * automatic simplification of integer sums and comparisons, using cancellation;
  6213 
  6214 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  6215 
  6216 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  6217 
  6218 * many new identities for unions, intersections, set difference, etc.;
  6219 
  6220 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  6221 called split_if, split_split, split_sum_case and split_nat_case (to go
  6222 with add/delsplits);
  6223 
  6224 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  6225 (?x::unit) = (); this is made part of the default simpset, which COULD
  6226 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  6227 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  6228 unit_abs_eta_conv is added in order to counter the effect of
  6229 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  6230 %u.f();
  6231 
  6232 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  6233 makes more sense);
  6234 
  6235 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6236   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6237   disjointness reasoning but breaking a few old proofs.
  6238