NEWS
author haftmann
Thu, 23 Dec 2010 12:04:29 +0100
changeset 41645 f5e14d6f5eba
parent 41628 b31d7a1cd08f
child 41646 f2bb6541f532
permissions -rw-r--r--
NEWS
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Significantly improved Isabelle/Isar implementation manual.
    10 
    11 * Source files are always encoded as UTF-8, instead of old-fashioned
    12 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
    13 the following package declarations:
    14 
    15   \usepackage[utf8]{inputenc}
    16   \usepackage{textcomp}
    17 
    18 * Explicit treatment of UTF8 sequences as Isabelle symbols, such that
    19 a Unicode character is treated as a single symbol, not a sequence of
    20 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    21 contain symbols without further backslash escapes, Unicode can now be
    22 used here as well.  Recall that Symbol.explode in ML provides a
    23 consistent view on symbols, while raw explode (or String.explode)
    24 merely give a byte-oriented representation.
    25 
    26 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
    27 (and thus refers to something like $HOME/.isabelle/IsabelleXXXX),
    28 while the default heap location within that directory lacks that extra
    29 suffix.  This isolates multiple Isabelle installations from each
    30 other, avoiding problems with old settings in new versions.
    31 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
    32 
    33 * Theory loading: only the master source file is looked-up in the
    34 implicit load path, all other files are addressed relatively to its
    35 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    36 
    37 * Special treatment of ML file names has been discontinued.
    38 Historically, optional extensions .ML or .sml were added on demand --
    39 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    40 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    41 
    42 * Various options that affect pretty printing etc. are now properly
    43 handled within the context via configuration options, instead of
    44 unsynchronized references or print modes.  There are both ML Config.T
    45 entities and Isar declaration attributes to access these.
    46 
    47   ML (Config.T)                 Isar (attribute)
    48 
    49   eta_contract                  eta_contract
    50   show_brackets                 show_brackets
    51   show_sorts                    show_sorts
    52   show_types                    show_types
    53   show_question_marks           show_question_marks
    54   show_consts                   show_consts
    55   show_abbrevs                  show_abbrevs
    56 
    57   Syntax.ast_trace              syntax_ast_trace
    58   Syntax.ast_stat               syntax_ast_stat
    59   Syntax.ambiguity_level        syntax_ambiguity_level
    60 
    61   Goal_Display.goals_limit      goals_limit
    62   Goal_Display.show_main_goal   show_main_goal
    63 
    64   Method.rule_trace             rule_trace
    65 
    66   Thy_Output.display            thy_output_display
    67   Thy_Output.quotes             thy_output_quotes
    68   Thy_Output.indent             thy_output_indent
    69   Thy_Output.source             thy_output_source
    70   Thy_Output.break              thy_output_break
    71 
    72 Note that corresponding "..._default" references in ML may be only
    73 changed globally at the ROOT session setup, but *not* within a theory.
    74 The option "show_abbrevs" supersedes the former print mode
    75 "no_abbrevs" with inverted meaning.
    76 
    77 * More systematic naming of some configuration options.
    78 INCOMPATIBILITY.
    79 
    80   trace_simp  ~>  simp_trace
    81   debug_simp  ~>  simp_debug
    82 
    83 * Support for real valued configuration options, using simplistic
    84 floating-point notation that coincides with the inner syntax for
    85 float_token.
    86 
    87 
    88 *** Pure ***
    89 
    90 * Command 'type_synonym' (with single argument) replaces somewhat
    91 outdated 'types', which is still available as legacy feature for some
    92 time.
    93 
    94 * Command 'nonterminal' (with 'and' separated list of arguments)
    95 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
    96 
    97 * Command 'notepad' replaces former 'example_proof' for
    98 experimentation in Isar without any result.  INCOMPATIBILITY.
    99 
   100 * Support for real valued preferences (with approximative PGIP type).
   101 
   102 * Interpretation command 'interpret' accepts a list of equations like
   103 'interpretation' does.
   104 
   105 * Diagnostic command 'print_interps' prints interpretations in proofs
   106 in addition to interpretations in theories.
   107 
   108 * Discontinued obsolete 'global' and 'local' commands to manipulate
   109 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   110 Sign.root_path and Sign.local_path may be applied directly where this
   111 feature is still required for historical reasons.
   112 
   113 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   114 'definition' instead.
   115 
   116 * Document antiquotations @{class} and @{type} print classes and type
   117 constructors.
   118 
   119 * Document antiquotation @{file} checks file/directory entries within
   120 the local file system.
   121 
   122 
   123 *** HOL ***
   124 
   125 * More canonical naming convention for some fundamental definitions:
   126 
   127     bot_bool_eq ~> bot_bool_def
   128     top_bool_eq ~> top_bool_def
   129     inf_bool_eq ~> inf_bool_def
   130     sup_bool_eq ~> sup_bool_def
   131     bot_fun_eq ~> bot_fun_def
   132     top_fun_eq ~> top_fun_def
   133     inf_fun_eq ~> inf_fun_def
   134     sup_fun_eq ~> sup_fun_def
   135 
   136 * Quickcheck now by default uses exhaustive testing instead of random
   137 testing.  Random testing can be invoked by quickcheck[random],
   138 exhaustive testing by quickcheck[exhaustive].
   139 
   140 * Quickcheck instantiates polymorphic types with small finite
   141 datatypes by default. This enables a simple execution mechanism to
   142 handle quantifiers and function equality over the finite datatypes.
   143 
   144 * Functions can be declared as coercions and type inference will add
   145 them as necessary upon input of a term. In theory Complex_Main,
   146 real :: nat => real and real :: int => real are declared as
   147 coercions. A new coercion function f is declared like this:
   148 
   149   declare [[coercion f]]
   150 
   151 To lift coercions through type constructors (eg from nat => real to
   152 nat list => real list), map functions can be declared, e.g.
   153 
   154   declare [[coercion_map map]]
   155 
   156 Currently coercion inference is activated only in theories including
   157 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   158 the configuration option "coercion_enabled", e.g. it can be enabled in
   159 other theories like this:
   160 
   161   declare [[coercion_enabled]]
   162 
   163 * Abandoned locales equiv, congruent and congruent2 for equivalence
   164 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   165 for congruent(2)).
   166 
   167 * Code generator: globbing constant expressions "*" and "Theory.*"
   168 have been replaced by the more idiomatic "_" and "Theory._".
   169 INCOMPATIBILITY.
   170 
   171 * Theory Enum (for explicit enumerations of finite types) is now part
   172 of the HOL-Main image. INCOMPATIBILITY: all constants of the Enum
   173 theory now have to be referred to by its qualified name.
   174 
   175   enum    ~>  Enum.enum
   176   nlists  ~>  Enum.nlists
   177   product ~>  Enum.product
   178 
   179 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   180 avoid confusion with finite sets.  INCOMPATIBILITY.
   181 
   182 * Quickcheck's generator for random generation is renamed from "code"
   183 to "random".  INCOMPATIBILITY.
   184 
   185 * Quickcheck now has a configurable time limit which is set to 30
   186 seconds by default. This can be changed by adding [timeout = n] to the
   187 quickcheck command. The time limit for Auto Quickcheck is still set
   188 independently.
   189 
   190 * Theory Multiset provides stable quicksort implementation of
   191 sort_key.
   192 
   193 * New command 'partial_function' provides basic support for recursive
   194 function definitions over complete partial orders. Concrete instances
   195 are provided for i) the option type, ii) tail recursion on arbitrary
   196 types, and iii) the heap monad of Imperative_HOL. See
   197 HOL/ex/Fundefs.thy and HOL/Imperative_HOL/ex/Linked_Lists.thy for
   198 examples.
   199 
   200 * New command 'type_lifting' allows to register properties on
   201 the functorial structure of types.
   202 
   203 * Predicate "sorted" now defined inductively, with
   204 nice induction rules.  INCOMPATIBILITY: former sorted.simps now
   205 named sorted_simps.
   206 
   207 * Constant "contents" renamed to "the_elem", to free the generic name
   208 contents for other uses.  INCOMPATIBILITY.
   209 
   210 * Dropped syntax for old primrec package.  INCOMPATIBILITY.
   211 
   212 * Improved infrastructure for term evaluation using code generator
   213 techniques, in particular static evaluation conversions.
   214 
   215 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   216 
   217 * Renamed facts:
   218   expand_fun_eq  ~>  fun_eq_iff
   219   expand_set_eq  ~>  set_eq_iff
   220   set_ext        ~>  set_eqI
   221   nat_number     ~>  eval_nat_numeral
   222 
   223 * Renamed class eq and constant eq (for code generation) to class
   224 equal and constant equal, plus renaming of related facts and various
   225 tuning.  INCOMPATIBILITY.
   226 
   227 * Scala (2.8 or higher) has been added to the target languages of the
   228 code generator.
   229 
   230 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   231 
   232 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".  INCOMPATIBILITY.
   233 
   234 * Theory SetsAndFunctions has been split into Function_Algebras and
   235 Set_Algebras; canonical names for instance definitions for functions;
   236 various improvements.  INCOMPATIBILITY.
   237 
   238 * Records: logical foundation type for records do not carry a '_type'
   239 suffix any longer.  INCOMPATIBILITY.
   240 
   241 * Code generation for records: more idiomatic representation of record
   242 types.  Warning: records are not covered by ancient SML code
   243 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   244 rep_datatype declaration helps to succeed then:
   245 
   246   record 'a foo = ...
   247   ...
   248   rep_datatype foo_ext ...
   249 
   250 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   251 INCOMPATIBILITY.
   252 
   253 * Quickcheck in locales considers interpretations of that locale for
   254 counter example search.
   255 
   256 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   257 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   258 INCOMPATIBILITY.
   259 
   260 * Code generator: export_code without explicit file declaration prints
   261 to standard output.  INCOMPATIBILITY.
   262 
   263 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   264 "*" and "+" respectively.  INCOMPATIBILITY.
   265 
   266 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   267 Sum_Type.Plus.
   268 
   269 * Constant "split" has been merged with constant "prod_case"; names of
   270 ML functions, facts etc. involving split have been retained so far,
   271 though.  INCOMPATIBILITY.
   272 
   273 * Dropped old infix syntax "mem" for List.member; use "in set"
   274 instead.  INCOMPATIBILITY.
   275 
   276 * Refactoring of code-generation specific operations in List.thy
   277 
   278   constants
   279     null ~> List.null
   280 
   281   facts
   282     mem_iff ~> member_def
   283     null_empty ~> null_def
   284 
   285 INCOMPATIBILITY.  Note that these were not supposed to be used
   286 regularly unless for striking reasons; their main purpose was code
   287 generation.
   288 
   289 * Some previously unqualified names have been qualified:
   290 
   291   types
   292     bool ~> HOL.bool
   293     nat ~> Nat.nat
   294 
   295   constants
   296     Trueprop ~> HOL.Trueprop
   297     True ~> HOL.True
   298     False ~> HOL.False
   299     op & ~> HOL.conj
   300     op | ~> HOL.disj
   301     op --> ~> HOL.implies
   302     op = ~> HOL.eq
   303     Not ~> HOL.Not
   304     The ~> HOL.The
   305     All ~> HOL.All
   306     Ex ~> HOL.Ex
   307     Ex1 ~> HOL.Ex1
   308     Let ~> HOL.Let
   309     If ~> HOL.If
   310     Ball ~> Set.Ball
   311     Bex ~> Set.Bex
   312     Suc ~> Nat.Suc
   313     Pair ~> Product_Type.Pair
   314     fst ~> Product_Type.fst
   315     snd ~> Product_Type.snd
   316     curry ~> Product_Type.curry
   317     op : ~> Set.member
   318     Collect ~> Set.Collect
   319 
   320 INCOMPATIBILITY.
   321 
   322 * Removed simplifier congruence rule of "prod_case", as has for long
   323 been the case with "split".  INCOMPATIBILITY.
   324 
   325 * Datatype package: theorems generated for executable equality (class
   326 eq) carry proper names and are treated as default code equations.
   327 
   328 * Removed lemma Option.is_none_none (Duplicate of is_none_def).
   329 INCOMPATIBILITY.
   330 
   331 * List.thy: use various operations from the Haskell prelude when
   332 generating Haskell code.
   333 
   334 * Multiset.thy: renamed empty_idemp -> empty_neutral
   335 
   336 * code_simp.ML and method code_simp: simplification with rules
   337 determined by code generator.
   338 
   339 * code generator: do not print function definitions for case
   340 combinators any longer.
   341 
   342 * Multivariate Analysis: Introduced a type class for euclidean
   343 space. Most theorems are now stated in terms of euclidean spaces
   344 instead of finite cartesian products.
   345 
   346   types
   347     real ^ 'n ~>  'a::real_vector
   348               ~>  'a::euclidean_space
   349               ~>  'a::ordered_euclidean_space
   350         (depends on your needs)
   351 
   352   constants
   353      _ $ _        ~> _ $$ _
   354      \<chi> x. _  ~> \<chi>\<chi> x. _
   355      CARD('n)     ~> DIM('a)
   356 
   357 Also note that the indices are now natural numbers and not from some
   358 finite type. Finite cartesian products of euclidean spaces, products
   359 of euclidean spaces the real and complex numbers are instantiated to
   360 be euclidean_spaces.  INCOMPATIBILITY.
   361 
   362 * Probability: Introduced pextreal as positive extended real numbers.
   363 Use pextreal as value for measures. Introduce the Radon-Nikodym
   364 derivative, product spaces and Fubini's theorem for arbitrary sigma
   365 finite measures. Introduces Lebesgue measure based on the integral in
   366 Multivariate Analysis.  INCOMPATIBILITY.
   367 
   368 * Inductive package: offers new command 'inductive_simps' to
   369 automatically derive instantiated and simplified equations for
   370 inductive predicates, similar to 'inductive_cases'.
   371 
   372 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". "surj f"
   373 is now an abbreviation of "range f = UNIV". The theorems bij_def and
   374 surj_def are unchanged.  INCOMPATIBILITY.
   375 
   376 * Function package: .psimps rules are no longer implicitly declared
   377 [simp].  INCOMPATIBILITY.
   378 
   379 * Weaker versions of the "meson" and "metis" proof methods are now
   380 available in "HOL-Plain", without dependency on "Hilbert_Choice". The
   381 proof methods become more powerful after "Hilbert_Choice" is loaded in
   382 "HOL-Main".
   383 
   384 * MESON: Renamed lemmas:
   385   meson_not_conjD ~> Meson.not_conjD
   386   meson_not_disjD ~> Meson.not_disjD
   387   meson_not_notD ~> Meson.not_notD
   388   meson_not_allD ~> Meson.not_allD
   389   meson_not_exD ~> Meson.not_exD
   390   meson_imp_to_disjD ~> Meson.imp_to_disjD
   391   meson_not_impD ~> Meson.not_impD
   392   meson_iff_to_disjD ~> Meson.iff_to_disjD
   393   meson_not_iffD ~> Meson.not_iffD
   394   meson_not_refl_disj_D ~> Meson.not_refl_disj_D
   395   meson_conj_exD1 ~> Meson.conj_exD1
   396   meson_conj_exD2 ~> Meson.conj_exD2
   397   meson_disj_exD ~> Meson.disj_exD
   398   meson_disj_exD1 ~> Meson.disj_exD1
   399   meson_disj_exD2 ~> Meson.disj_exD2
   400   meson_disj_assoc ~> Meson.disj_assoc
   401   meson_disj_comm ~> Meson.disj_comm
   402   meson_disj_FalseD1 ~> Meson.disj_FalseD1
   403   meson_disj_FalseD2 ~> Meson.disj_FalseD2
   404 INCOMPATIBILITY.
   405 
   406 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   407 manually as command 'solve_direct'.
   408 
   409 * Sledgehammer:
   410   - Added "smt" and "remote_smt" provers based on the "smt" proof method. See
   411     the Sledgehammer manual for details ("isabelle doc sledgehammer").
   412   - Renamed lemmas:
   413     COMBI_def ~> Meson.COMBI_def
   414     COMBK_def ~> Meson.COMBK_def
   415     COMBB_def ~> Meson.COMBB_def
   416     COMBC_def ~> Meson.COMBC_def
   417     COMBS_def ~> Meson.COMBS_def
   418     abs_I ~> Meson.abs_I
   419     abs_K ~> Meson.abs_K
   420     abs_B ~> Meson.abs_B
   421     abs_C ~> Meson.abs_C
   422     abs_S ~> Meson.abs_S
   423     INCOMPATIBILITY.
   424   - Renamed commands:
   425     sledgehammer atp_info ~> sledgehammer running_provers
   426     sledgehammer atp_kill ~> sledgehammer kill_provers
   427     sledgehammer available_atps ~> sledgehammer available_provers
   428     INCOMPATIBILITY.
   429   - Renamed options:
   430     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   431     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   432     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   433     (and "ms" and "min" are no longer supported)
   434     INCOMPATIBILITY.
   435 
   436 * Metis and Meson now have configuration options "meson_trace",
   437 "metis_trace", and "metis_verbose" that can be enabled to diagnose
   438 these tools. E.g.
   439 
   440     using [[metis_trace = true]]
   441 
   442 * Nitpick:
   443   - Renamed options:
   444     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   445     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   446     INCOMPATIBILITY.
   447   - Now requires Kodkodi 1.2.9. INCOMPATIBILITY.
   448   - Added support for partial quotient types.
   449   - Added local versions of the "Nitpick.register_xxx" functions.
   450   - Added "whack" option.
   451   - Allow registration of quotient types as codatatypes.
   452   - Improved "merge_type_vars" option to merge more types.
   453   - Removed unsound "fast_descrs" option.
   454   - Added custom symmetry breaking for datatypes, making it possible to reach
   455     higher cardinalities.
   456   - Prevent the expansion of too large definitions.
   457 
   458 * Changed SMT configuration options:
   459   - Renamed:
   460     z3_proofs ~> smt_oracle (with swapped semantics)
   461     z3_trace_assms ~> smt_trace_used_facts
   462     INCOMPATIBILITY.
   463   - Added:
   464     smt_verbose
   465     smt_datatypes
   466     cvc3_options
   467     yices_options
   468 
   469 * Boogie output files (.b2i files) need to be declared in the theory
   470 header.
   471 
   472 * Removed [split_format ... and ... and ...] version of
   473 [split_format].  Potential INCOMPATIBILITY.
   474 
   475 
   476 *** HOLCF ***
   477 
   478 * The domain package now runs in definitional mode by default: The
   479 former command 'new_domain' is now called 'domain'. To use the domain
   480 package in its original axiomatic mode, use 'domain (unsafe)'.
   481 INCOMPATIBILITY.
   482 
   483 * The new class 'domain' is now the default sort; the definitional
   484 domain package and the powerdomain theories both require this class.
   485 The new class 'predomain' is an unpointed version of 'domain'.
   486 Theories can be updated by replacing sort annotations as shown below.
   487 INCOMPATIBILITY.
   488 
   489   'a::type ~> 'a::countable
   490   'a::cpo  ~> 'a::predomain
   491   'a::pcpo ~> 'a::domain
   492 
   493 * The old type class 'rep' has been superseded by class 'domain'.
   494 Accordingly, users of the definitional package must remove any
   495 'default_sort rep' declarations. INCOMPATIBILITY.
   496 
   497 * The 'bifinite' class no longer fixes a constant 'approx'; the class
   498 now just asserts that such a function exists. INCOMPATIBILITY.
   499 
   500 * The type 'alg_defl' has been renamed to 'defl'. HOLCF no longer
   501 defines an embedding of type 'a defl into udom by default; instances
   502 of 'bifinite' and 'domain' classes are available in
   503 HOLCF/Library/Defl_Bifinite.thy.
   504 
   505 * The syntax 'REP('a)' has been replaced with 'DEFL('a)'.
   506 
   507 * The predicate 'directed' has been removed. INCOMPATIBILITY.
   508 
   509 * The type class 'finite_po' has been removed. INCOMPATIBILITY.
   510 
   511 * The function 'cprod_map' has been renamed to 'prod_map'.
   512 
   513 * Renamed some theorems (the original names are also still available).
   514   expand_fun_below   ~> fun_below_iff
   515   below_fun_ext      ~> fun_belowI
   516   expand_cfun_eq     ~> cfun_eq_iff
   517   ext_cfun           ~> cfun_eqI
   518   expand_cfun_below  ~> cfun_below_iff
   519   below_cfun_ext     ~> cfun_belowI
   520   cont2cont_Rep_CFun ~> cont2cont_APP
   521 
   522 * The Abs and Rep functions for various types have changed names.
   523 Related theorem names have also changed to match. INCOMPATIBILITY.
   524   Rep_CFun  ~> Rep_cfun
   525   Abs_CFun  ~> Abs_cfun
   526   Rep_Sprod ~> Rep_sprod
   527   Abs_Sprod ~> Abs_sprod
   528   Rep_Ssum  ~> Rep_ssum
   529   Abs_Ssum  ~> Abs_ssum
   530 
   531 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   532 been renamed to *_bottom_iff. INCOMPATIBILITY.
   533 
   534 * Various changes to bisimulation/coinduction with domain package:
   535   - Definitions of 'bisim' constants no longer mention definedness.
   536   - With mutual recursion, 'bisim' predicate is now curried.
   537   - With mutual recursion, each type gets a separate coind theorem.
   538   - Variable names in bisim_def and coinduct rules have changed.
   539 INCOMPATIBILITY.
   540 
   541 * Case combinators generated by the domain package for type 'foo' are
   542 now named 'foo_case' instead of 'foo_when'. INCOMPATIBILITY.
   543 
   544 * Several theorems have been renamed to more accurately reflect the
   545 names of constants and types involved. INCOMPATIBILITY.
   546   thelub_const    ~> lub_const
   547   lub_const       ~> is_lub_const
   548   thelubI         ~> lub_eqI
   549   is_lub_lub      ~> is_lubD2
   550   lubI            ~> is_lub_lub
   551   unique_lub      ~> is_lub_unique
   552   is_ub_lub       ~> is_lub_rangeD1
   553   lub_bin_chain   ~> is_lub_bin_chain
   554   lub_fun         ~> is_lub_fun
   555   thelub_fun      ~> lub_fun
   556   thelub_cfun     ~> lub_cfun
   557   thelub_Pair     ~> lub_Pair
   558   lub_cprod       ~> is_lub_prod
   559   thelub_cprod    ~> lub_prod
   560   minimal_cprod   ~> minimal_prod
   561   inst_cprod_pcpo ~> inst_prod_pcpo
   562 
   563 * Many legacy theorem names have been discontinued. INCOMPATIBILITY.
   564   sq_ord_less_eq_trans ~> below_eq_trans
   565   sq_ord_eq_less_trans ~> eq_below_trans
   566   refl_less            ~> below_refl
   567   trans_less           ~> below_trans
   568   antisym_less         ~> below_antisym
   569   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   570   box_less             ~> box_below
   571   rev_trans_less       ~> rev_below_trans
   572   not_less2not_eq      ~> not_below2not_eq
   573   less_UU_iff          ~> below_UU_iff
   574   flat_less_iff        ~> flat_below_iff
   575   adm_less             ~> adm_below
   576   adm_not_less         ~> adm_not_below
   577   adm_compact_not_less ~> adm_compact_not_below
   578   less_fun_def         ~> below_fun_def
   579   expand_fun_less      ~> fun_below_iff
   580   less_fun_ext         ~> fun_belowI
   581   less_discr_def       ~> below_discr_def
   582   discr_less_eq        ~> discr_below_eq
   583   less_unit_def        ~> below_unit_def
   584   less_cprod_def       ~> below_prod_def
   585   prod_lessI           ~> prod_belowI
   586   Pair_less_iff        ~> Pair_below_iff
   587   fst_less_iff         ~> fst_below_iff
   588   snd_less_iff         ~> snd_below_iff
   589   expand_cfun_less     ~> cfun_below_iff
   590   less_cfun_ext        ~> cfun_belowI
   591   injection_less       ~> injection_below
   592   less_up_def          ~> below_up_def
   593   not_Iup_less         ~> not_Iup_below
   594   Iup_less             ~> Iup_below
   595   up_less              ~> up_below
   596   Def_inject_less_eq   ~> Def_below_Def
   597   Def_less_is_eq       ~> Def_below_iff
   598   spair_less_iff       ~> spair_below_iff
   599   less_sprod           ~> below_sprod
   600   spair_less           ~> spair_below
   601   sfst_less_iff        ~> sfst_below_iff
   602   ssnd_less_iff        ~> ssnd_below_iff
   603   fix_least_less       ~> fix_least_below
   604   dist_less_one        ~> dist_below_one
   605   less_ONE             ~> below_ONE
   606   ONE_less_iff         ~> ONE_below_iff
   607   less_sinlD           ~> below_sinlD
   608   less_sinrD           ~> below_sinrD
   609 
   610 
   611 *** FOL and ZF ***
   612 
   613 * All constant names are now qualified internally and use proper
   614 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   615 
   616 
   617 
   618 *** ML ***
   619 
   620 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   621 main functionality is provided by structure Simplifier.
   622 
   623 * Syntax.pretty_priority (default 0) configures the required priority
   624 of pretty-printed output and thus affects insertion of parentheses.
   625 
   626 * Syntax.default_root (default "any") configures the inner syntax
   627 category (nonterminal symbol) for parsing of terms.
   628 
   629 * Former exception Library.UnequalLengths now coincides with
   630 ListPair.UnequalLengths.
   631 
   632 * Renamed raw "explode" function to "raw_explode" to emphasize its
   633 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   634 almost all situations.
   635 
   636 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   637 See implementation manual for further details on exceptions in
   638 Isabelle/ML.
   639 
   640 * Antiquotation @{assert} inlines a function bool -> unit that raises
   641 Fail if the argument is false.  Due to inlining the source position of
   642 failed assertions is included in the error output.
   643 
   644 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   645 text is in practice always evaluated with a stable theory checkpoint.
   646 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   647 
   648 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   649 meaning.
   650 
   651 * Renamed structure PureThy to Pure_Thy and moved most of its
   652 operations to structure Global_Theory, to emphasize that this is
   653 rarely-used global-only stuff.
   654 
   655 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   656 instead (or tracing for high-volume output).
   657 
   658 * Configuration option show_question_marks only affects regular pretty
   659 printing of types and terms, not raw Term.string_of_vname.
   660 
   661 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   662 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   663 @{thms} for most purposes.
   664 
   665 * ML structure Unsynchronized never opened, not even in Isar
   666 interaction mode as before.  Old Unsynchronized.set etc. have been
   667 discontinued -- use plain := instead.  This should be *rare* anyway,
   668 since modern tools always work via official context data, notably
   669 configuration options.
   670 
   671 * ML antiquotations @{theory} and @{theory_ref} refer to named
   672 theories from the ancestry of the current context, not any accidental
   673 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   674 change in semantics.
   675 
   676 * Parallel and asynchronous execution requires special care concerning
   677 interrupts.  Structure Exn provides some convenience functions that
   678 avoid working directly with raw Interrupt.  User code must not absorb
   679 interrupts -- intermediate handling (for cleanup etc.) needs to be
   680 followed by re-raising of the original exception.  Another common
   681 source of mistakes are "handle _" patterns, which make the meaning of
   682 the program subject to physical effects of the environment.
   683 
   684 
   685 *** System ***
   686 
   687 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   688 DajaVu Sans.
   689 
   690 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   691 
   692 
   693 
   694 New in Isabelle2009-2 (June 2010)
   695 ---------------------------------
   696 
   697 *** General ***
   698 
   699 * Authentic syntax for *all* logical entities (type classes, type
   700 constructors, term constants): provides simple and robust
   701 correspondence between formal entities and concrete syntax.  Within
   702 the parse tree / AST representations, "constants" are decorated by
   703 their category (class, type, const) and spelled out explicitly with
   704 their full internal name.
   705 
   706 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   707 and translations (translation rules and translation functions in ML).
   708 Some hints on upgrading:
   709 
   710   - Many existing uses of 'syntax' and 'translations' can be replaced
   711     by more modern 'type_notation', 'notation' and 'abbreviation',
   712     which are independent of this issue.
   713 
   714   - 'translations' require markup within the AST; the term syntax
   715     provides the following special forms:
   716 
   717       CONST c   -- produces syntax version of constant c from context
   718       XCONST c  -- literally c, checked as constant from context
   719       c         -- literally c, if declared by 'syntax'
   720 
   721     Plain identifiers are treated as AST variables -- occasionally the
   722     system indicates accidental variables via the error "rhs contains
   723     extra variables".
   724 
   725     Type classes and type constructors are marked according to their
   726     concrete syntax.  Some old translations rules need to be written
   727     for the "type" category, using type constructor application
   728     instead of pseudo-term application of the default category
   729     "logic".
   730 
   731   - 'parse_translation' etc. in ML may use the following
   732     antiquotations:
   733 
   734       @{class_syntax c}   -- type class c within parse tree / AST
   735       @{term_syntax c}    -- type constructor c within parse tree / AST
   736       @{const_syntax c}   -- ML version of "CONST c" above
   737       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   738 
   739   - Literal types within 'typed_print_translations', i.e. those *not*
   740     represented as pseudo-terms are represented verbatim.  Use @{class
   741     c} or @{type_name c} here instead of the above syntax
   742     antiquotations.
   743 
   744 Note that old non-authentic syntax was based on unqualified base
   745 names, so all of the above "constant" names would coincide.  Recall
   746 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   747 diagnose syntax problems.
   748 
   749 * Type constructors admit general mixfix syntax, not just infix.
   750 
   751 * Concrete syntax may be attached to local entities without a proof
   752 body, too.  This works via regular mixfix annotations for 'fix',
   753 'def', 'obtain' etc. or via the explicit 'write' command, which is
   754 similar to the 'notation' command in theory specifications.
   755 
   756 * Discontinued unnamed infix syntax (legacy feature for many years) --
   757 need to specify constant name and syntax separately.  Internal ML
   758 datatype constructors have been renamed from InfixName to Infix etc.
   759 Minor INCOMPATIBILITY.
   760 
   761 * Schematic theorem statements need to be explicitly markup as such,
   762 via commands 'schematic_lemma', 'schematic_theorem',
   763 'schematic_corollary'.  Thus the relevance of the proof is made
   764 syntactically clear, which impacts performance in a parallel or
   765 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   766 
   767 * Use of cumulative prems via "!" in some proof methods has been
   768 discontinued (old legacy feature).
   769 
   770 * References 'trace_simp' and 'debug_simp' have been replaced by
   771 configuration options stored in the context. Enabling tracing (the
   772 case of debugging is similar) in proofs works via
   773 
   774   using [[trace_simp = true]]
   775 
   776 Tracing is then active for all invocations of the simplifier in
   777 subsequent goal refinement steps. Tracing may also still be enabled or
   778 disabled via the ProofGeneral settings menu.
   779 
   780 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   781 'hide_fact' replace the former 'hide' KIND command.  Minor
   782 INCOMPATIBILITY.
   783 
   784 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   785 more efficient than combinations with -q1 or -q2.
   786 
   787 
   788 *** Pure ***
   789 
   790 * Proofterms record type-class reasoning explicitly, using the
   791 "unconstrain" operation internally.  This eliminates all sort
   792 constraints from a theorem and proof, introducing explicit
   793 OFCLASS-premises.  On the proof term level, this operation is
   794 automatically applied at theorem boundaries, such that closed proofs
   795 are always free of sort constraints.  INCOMPATIBILITY for tools that
   796 inspect proof terms.
   797 
   798 * Local theory specifications may depend on extra type variables that
   799 are not present in the result type -- arguments TYPE('a) :: 'a itself
   800 are added internally.  For example:
   801 
   802   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   803 
   804 * Predicates of locales introduced by classes carry a mandatory
   805 "class" prefix.  INCOMPATIBILITY.
   806 
   807 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   808 
   809 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   810 'class' instead.
   811 
   812 * Command 'code_reflect' allows to incorporate generated ML code into
   813 runtime environment; replaces immature code_datatype antiquotation.
   814 INCOMPATIBILITY.
   815 
   816 * Code generator: simple concept for abstract datatypes obeying
   817 invariants.
   818 
   819 * Code generator: details of internal data cache have no impact on the
   820 user space functionality any longer.
   821 
   822 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   823 subgoals.  This is more appropriate for interpretations with 'where'.
   824 INCOMPATIBILITY.
   825 
   826 * Command 'example_proof' opens an empty proof body.  This allows to
   827 experiment with Isar, without producing any persistent result.
   828 
   829 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   830 within a local theory context, with explicit checking of the
   831 constructors involved (in contrast to the raw 'syntax' versions).
   832 
   833 * Commands 'types' and 'typedecl' now work within a local theory
   834 context -- without introducing dependencies on parameters or
   835 assumptions, which is not possible in Isabelle/Pure.
   836 
   837 * Command 'defaultsort' has been renamed to 'default_sort', it works
   838 within a local theory context.  Minor INCOMPATIBILITY.
   839 
   840 
   841 *** HOL ***
   842 
   843 * Command 'typedef' now works within a local theory context -- without
   844 introducing dependencies on parameters or assumptions, which is not
   845 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   846 contain multiple interpretations of local typedefs (with different
   847 non-emptiness proofs), even in a global theory context.
   848 
   849 * New package for quotient types.  Commands 'quotient_type' and
   850 'quotient_definition' may be used for defining types and constants by
   851 quotient constructions.  An example is the type of integers created by
   852 quotienting pairs of natural numbers:
   853 
   854   fun
   855     intrel :: "(nat * nat) => (nat * nat) => bool"
   856   where
   857     "intrel (x, y) (u, v) = (x + v = u + y)"
   858 
   859   quotient_type int = "nat * nat" / intrel
   860     by (auto simp add: equivp_def expand_fun_eq)
   861 
   862   quotient_definition
   863     "0::int" is "(0::nat, 0::nat)"
   864 
   865 The method "lifting" can be used to lift of theorems from the
   866 underlying "raw" type to the quotient type.  The example
   867 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   868 construction and provides a reasoning infrastructure for finite sets.
   869 
   870 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   871 clash with new theory Quotient in Main HOL.
   872 
   873 * Moved the SMT binding into the main HOL session, eliminating
   874 separate HOL-SMT session.
   875 
   876 * List membership infix mem operation is only an input abbreviation.
   877 INCOMPATIBILITY.
   878 
   879 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   880 for future developements; former Library/Word.thy is still present in
   881 the AFP entry RSAPPS.
   882 
   883 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   884 longer shadowed.  INCOMPATIBILITY.
   885 
   886 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   887 INCOMPATIBILITY.
   888 
   889 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   890 INCOMPATIBILITY.
   891 
   892 * Dropped normalizing_semiring etc; use the facts in semiring classes
   893 instead.  INCOMPATIBILITY.
   894 
   895 * Dropped several real-specific versions of lemmas about floor and
   896 ceiling; use the generic lemmas from theory "Archimedean_Field"
   897 instead.  INCOMPATIBILITY.
   898 
   899   floor_number_of_eq         ~> floor_number_of
   900   le_floor_eq_number_of      ~> number_of_le_floor
   901   le_floor_eq_zero           ~> zero_le_floor
   902   le_floor_eq_one            ~> one_le_floor
   903   floor_less_eq_number_of    ~> floor_less_number_of
   904   floor_less_eq_zero         ~> floor_less_zero
   905   floor_less_eq_one          ~> floor_less_one
   906   less_floor_eq_number_of    ~> number_of_less_floor
   907   less_floor_eq_zero         ~> zero_less_floor
   908   less_floor_eq_one          ~> one_less_floor
   909   floor_le_eq_number_of      ~> floor_le_number_of
   910   floor_le_eq_zero           ~> floor_le_zero
   911   floor_le_eq_one            ~> floor_le_one
   912   floor_subtract_number_of   ~> floor_diff_number_of
   913   floor_subtract_one         ~> floor_diff_one
   914   ceiling_number_of_eq       ~> ceiling_number_of
   915   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   916   ceiling_le_zero_eq         ~> ceiling_le_zero
   917   ceiling_le_eq_one          ~> ceiling_le_one
   918   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   919   less_ceiling_eq_zero       ~> zero_less_ceiling
   920   less_ceiling_eq_one        ~> one_less_ceiling
   921   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   922   ceiling_less_eq_zero       ~> ceiling_less_zero
   923   ceiling_less_eq_one        ~> ceiling_less_one
   924   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   925   le_ceiling_eq_zero         ~> zero_le_ceiling
   926   le_ceiling_eq_one          ~> one_le_ceiling
   927   ceiling_subtract_number_of ~> ceiling_diff_number_of
   928   ceiling_subtract_one       ~> ceiling_diff_one
   929 
   930 * Theory "Finite_Set": various folding_XXX locales facilitate the
   931 application of the various fold combinators on finite sets.
   932 
   933 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   934 provides abstract red-black tree type which is backed by "RBT_Impl" as
   935 implementation.  INCOMPATIBILTY.
   936 
   937 * Theory Library/Coinductive_List has been removed -- superseded by
   938 AFP/thys/Coinductive.
   939 
   940 * Theory PReal, including the type "preal" and related operations, has
   941 been removed.  INCOMPATIBILITY.
   942 
   943 * Real: new development using Cauchy Sequences.
   944 
   945 * Split off theory "Big_Operators" containing setsum, setprod,
   946 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   947 
   948 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   949 "Int" etc.  INCOMPATIBILITY.
   950 
   951 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   952 
   953 * New set of rules "ac_simps" provides combined assoc / commute
   954 rewrites for all interpretations of the appropriate generic locales.
   955 
   956 * Renamed theory "OrderedGroup" to "Groups" and split theory
   957 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   958 appropriate and more consistent names suitable for name prefixes
   959 within the HOL theories.  INCOMPATIBILITY.
   960 
   961 * Some generic constants have been put to appropriate theories:
   962   - less_eq, less: Orderings
   963   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   964   - inverse, divide: Rings
   965 INCOMPATIBILITY.
   966 
   967 * More consistent naming of type classes involving orderings (and
   968 lattices):
   969 
   970     lower_semilattice                   ~> semilattice_inf
   971     upper_semilattice                   ~> semilattice_sup
   972 
   973     dense_linear_order                  ~> dense_linorder
   974 
   975     pordered_ab_group_add               ~> ordered_ab_group_add
   976     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   977     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   978     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   979     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   980     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   981     pordered_cancel_semiring            ~> ordered_cancel_semiring
   982     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   983     pordered_comm_ring                  ~> ordered_comm_ring
   984     pordered_comm_semiring              ~> ordered_comm_semiring
   985     pordered_ring                       ~> ordered_ring
   986     pordered_ring_abs                   ~> ordered_ring_abs
   987     pordered_semiring                   ~> ordered_semiring
   988 
   989     ordered_ab_group_add                ~> linordered_ab_group_add
   990     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   991     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   992     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   993     ordered_field                       ~> linordered_field
   994     ordered_field_no_lb                 ~> linordered_field_no_lb
   995     ordered_field_no_ub                 ~> linordered_field_no_ub
   996     ordered_field_dense_linear_order    ~> dense_linordered_field
   997     ordered_idom                        ~> linordered_idom
   998     ordered_ring                        ~> linordered_ring
   999     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1000     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1001     ordered_ring_strict                 ~> linordered_ring_strict
  1002     ordered_semidom                     ~> linordered_semidom
  1003     ordered_semiring                    ~> linordered_semiring
  1004     ordered_semiring_1                  ~> linordered_semiring_1
  1005     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1006     ordered_semiring_strict             ~> linordered_semiring_strict
  1007 
  1008   The following slightly odd type classes have been moved to a
  1009   separate theory Library/Lattice_Algebras:
  1010 
  1011     lordered_ab_group_add               ~> lattice_ab_group_add
  1012     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1013     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1014     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1015     lordered_ring                       ~> lattice_ring
  1016 
  1017 INCOMPATIBILITY.
  1018 
  1019 * Refined field classes:
  1020   - classes division_ring_inverse_zero, field_inverse_zero,
  1021     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1022     subsumes former division_by_zero class;
  1023   - numerous lemmas have been ported from field to division_ring.
  1024 INCOMPATIBILITY.
  1025 
  1026 * Refined algebra theorem collections:
  1027   - dropped theorem group group_simps, use algebra_simps instead;
  1028   - dropped theorem group ring_simps, use field_simps instead;
  1029   - proper theorem collection field_simps subsumes former theorem
  1030     groups field_eq_simps and field_simps;
  1031   - dropped lemma eq_minus_self_iff which is a duplicate for
  1032     equal_neg_zero.
  1033 INCOMPATIBILITY.
  1034 
  1035 * Theory Finite_Set and List: some lemmas have been generalized from
  1036 sets to lattices:
  1037 
  1038   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1039   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1040   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1041   union_Union_fold_union        ~> sup_Sup_fold_sup
  1042   Inter_fold_inter              ~> Inf_fold_inf
  1043   Union_fold_union              ~> Sup_fold_sup
  1044   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1045   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1046   INTER_fold_inter              ~> INFI_fold_inf
  1047   UNION_fold_union              ~> SUPR_fold_sup
  1048 
  1049 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1050 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1051 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1052 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1053 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1054 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1055 
  1056 * Reorganized theory Multiset: swapped notation of pointwise and
  1057 multiset order:
  1058 
  1059   - pointwise ordering is instance of class order with standard syntax
  1060     <= and <;
  1061   - multiset ordering has syntax <=# and <#; partial order properties
  1062     are provided by means of interpretation with prefix
  1063     multiset_order;
  1064   - less duplication, less historical organization of sections,
  1065     conversion from associations lists to multisets, rudimentary code
  1066     generation;
  1067   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1068     if needed.
  1069 
  1070 Renamed:
  1071 
  1072   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1073   multi_count_ext  ~>  multiset_ext
  1074   diff_union_inverse2  ~>  diff_union_cancelR
  1075 
  1076 INCOMPATIBILITY.
  1077 
  1078 * Theory Permutation: replaced local "remove" by List.remove1.
  1079 
  1080 * Code generation: ML and OCaml code is decorated with signatures.
  1081 
  1082 * Theory List: added transpose.
  1083 
  1084 * Library/Nat_Bijection.thy is a collection of bijective functions
  1085 between nat and other types, which supersedes the older libraries
  1086 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1087 
  1088   Constants:
  1089   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1090   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1091   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1092   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1093   Countable.pair_encode           ~> prod_encode
  1094   NatIso.prod2nat                 ~> prod_encode
  1095   NatIso.nat2prod                 ~> prod_decode
  1096   NatIso.sum2nat                  ~> sum_encode
  1097   NatIso.nat2sum                  ~> sum_decode
  1098   NatIso.list2nat                 ~> list_encode
  1099   NatIso.nat2list                 ~> list_decode
  1100   NatIso.set2nat                  ~> set_encode
  1101   NatIso.nat2set                  ~> set_decode
  1102 
  1103   Lemmas:
  1104   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1105   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1106   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1107   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1108   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1109   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1110   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1111   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1112   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1113   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1114   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1115   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1116   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1117 
  1118 * Sledgehammer:
  1119   - Renamed ATP commands:
  1120     atp_info     ~> sledgehammer running_atps
  1121     atp_kill     ~> sledgehammer kill_atps
  1122     atp_messages ~> sledgehammer messages
  1123     atp_minimize ~> sledgehammer minimize
  1124     print_atps   ~> sledgehammer available_atps
  1125     INCOMPATIBILITY.
  1126   - Added user's manual ("isabelle doc sledgehammer").
  1127   - Added option syntax and "sledgehammer_params" to customize
  1128     Sledgehammer's behavior.  See the manual for details.
  1129   - Modified the Isar proof reconstruction code so that it produces
  1130     direct proofs rather than proofs by contradiction.  (This feature
  1131     is still experimental.)
  1132   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1133     full-typed mode.
  1134   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1135 
  1136 * Nitpick:
  1137   - Added and implemented "binary_ints" and "bits" options.
  1138   - Added "std" option and implemented support for nonstandard models.
  1139   - Added and implemented "finitize" option to improve the precision
  1140     of infinite datatypes based on a monotonicity analysis.
  1141   - Added support for quotient types.
  1142   - Added support for "specification" and "ax_specification"
  1143     constructs.
  1144   - Added support for local definitions (for "function" and
  1145     "termination" proofs).
  1146   - Added support for term postprocessors.
  1147   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1148   - Improved efficiency of "destroy_constrs" optimization.
  1149   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1150     record getters.
  1151   - Fixed soundness bug related to higher-order constructors.
  1152   - Fixed soundness bug when "full_descrs" is enabled.
  1153   - Improved precision of set constructs.
  1154   - Added "atoms" option.
  1155   - Added cache to speed up repeated Kodkod invocations on the same
  1156     problems.
  1157   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1158     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1159     "SAT4J_Light".  INCOMPATIBILITY.
  1160   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1161     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1162   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1163 
  1164 * Method "induct" now takes instantiations of the form t, where t is not
  1165   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1166   If this is not intended, t has to be enclosed in parentheses.
  1167   By default, the equalities generated by definitional instantiations
  1168   are pre-simplified, which may cause parameters of inductive cases
  1169   to disappear, or may even delete some of the inductive cases.
  1170   Use "induct (no_simp)" instead of "induct" to restore the old
  1171   behaviour. The (no_simp) option is also understood by the "cases"
  1172   and "nominal_induct" methods, which now perform pre-simplification, too.
  1173   INCOMPATIBILITY.
  1174 
  1175 
  1176 *** HOLCF ***
  1177 
  1178 * Variable names in lemmas generated by the domain package have
  1179 changed; the naming scheme is now consistent with the HOL datatype
  1180 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1181 
  1182 * The domain package no longer defines the function "foo_copy" for
  1183 recursive domain "foo".  The reach lemma is now stated directly in
  1184 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1185 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1186 
  1187 * Most definedness lemmas generated by the domain package (previously
  1188 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1189 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1190 Proofs that used definedness lemmas as intro rules may break,
  1191 potential INCOMPATIBILITY.
  1192 
  1193 * Induction and casedist rules generated by the domain package now
  1194 declare proper case_names (one called "bottom", and one named for each
  1195 constructor).  INCOMPATIBILITY.
  1196 
  1197 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1198 rules are generated for each domain, INCOMPATIBILITY.
  1199 
  1200   foo_bar.reach       ~> foo.reach  bar.reach
  1201   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1202 
  1203 * Some lemmas generated by the domain package have been renamed for
  1204 consistency with the datatype package, INCOMPATIBILITY.
  1205 
  1206   foo.ind        ~> foo.induct
  1207   foo.finite_ind ~> foo.finite_induct
  1208   foo.coind      ~> foo.coinduct
  1209   foo.casedist   ~> foo.exhaust
  1210   foo.exhaust    ~> foo.nchotomy
  1211 
  1212 * For consistency with other definition packages, the fixrec package
  1213 now generates qualified theorem names, INCOMPATIBILITY.
  1214 
  1215   foo_simps  ~> foo.simps
  1216   foo_unfold ~> foo.unfold
  1217   foo_induct ~> foo.induct
  1218 
  1219 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1220 method and internal fixrec proofs now use the default simpset instead.
  1221 INCOMPATIBILITY.
  1222 
  1223 * The "contlub" predicate has been removed.  Proof scripts should use
  1224 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1225 
  1226 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1227 
  1228 * The constants cpair, cfst, and csnd have been removed in favor of
  1229 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1230 
  1231 
  1232 *** ML ***
  1233 
  1234 * Antiquotations for basic formal entities:
  1235 
  1236     @{class NAME}         -- type class
  1237     @{class_syntax NAME}  -- syntax representation of the above
  1238 
  1239     @{type_name NAME}     -- logical type
  1240     @{type_abbrev NAME}   -- type abbreviation
  1241     @{nonterminal NAME}   -- type of concrete syntactic category
  1242     @{type_syntax NAME}   -- syntax representation of any of the above
  1243 
  1244     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1245     @{const_abbrev NAME}  -- abbreviated constant
  1246     @{const_syntax NAME}  -- syntax representation of any of the above
  1247 
  1248 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1249 syntax constant (cf. 'syntax' command).
  1250 
  1251 * Antiquotation @{make_string} inlines a function to print arbitrary
  1252 values similar to the ML toplevel.  The result is compiler dependent
  1253 and may fall back on "?" in certain situations.
  1254 
  1255 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1256 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1257 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1258 not work with the asynchronous Isar document model.
  1259 
  1260 * Configuration options now admit dynamic default values, depending on
  1261 the context or even global references.
  1262 
  1263 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1264 uses an efficient external library if available (for Poly/ML).
  1265 
  1266 * Renamed some important ML structures, while keeping the old names
  1267 for some time as aliases within the structure Legacy:
  1268 
  1269   OuterKeyword  ~>  Keyword
  1270   OuterLex      ~>  Token
  1271   OuterParse    ~>  Parse
  1272   OuterSyntax   ~>  Outer_Syntax
  1273   PrintMode     ~>  Print_Mode
  1274   SpecParse     ~>  Parse_Spec
  1275   ThyInfo       ~>  Thy_Info
  1276   ThyLoad       ~>  Thy_Load
  1277   ThyOutput     ~>  Thy_Output
  1278   TypeInfer     ~>  Type_Infer
  1279 
  1280 Note that "open Legacy" simplifies porting of sources, but forgetting
  1281 to remove it again will complicate porting again in the future.
  1282 
  1283 * Most operations that refer to a global context are named
  1284 accordingly, e.g. Simplifier.global_context or
  1285 ProofContext.init_global.  There are some situations where a global
  1286 context actually works, but under normal circumstances one needs to
  1287 pass the proper local context through the code!
  1288 
  1289 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1290 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1291 Pretty.pp argument to merge, which is absent in the standard
  1292 Theory_Data version.
  1293 
  1294 * Sorts.certify_sort and derived "cert" operations for types and terms
  1295 no longer minimize sorts.  Thus certification at the boundary of the
  1296 inference kernel becomes invariant under addition of class relations,
  1297 which is an important monotonicity principle.  Sorts are now minimized
  1298 in the syntax layer only, at the boundary between the end-user and the
  1299 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1300 explicitly in rare situations.
  1301 
  1302 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1303 emphasize that this is in no way a standard operation.
  1304 INCOMPATIBILITY.
  1305 
  1306 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1307 usual for resolution.  Rare INCOMPATIBILITY.
  1308 
  1309 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1310 to emphasize that these only work in a global situation (which is
  1311 quite rare).
  1312 
  1313 * Curried take and drop in library.ML; negative length is interpreted
  1314 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1315 
  1316 * Proof terms: type substitutions on proof constants now use canonical
  1317 order of type variables.  INCOMPATIBILITY for tools working with proof
  1318 terms.
  1319 
  1320 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1321 may no longer carry premises.  User-level specifications are
  1322 transformed accordingly by Thm.add_axiom/add_def.
  1323 
  1324 
  1325 *** System ***
  1326 
  1327 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1328 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1329 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1330 
  1331 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1332 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1333 respectively.
  1334 
  1335 * Old lib/scripts/polyml-platform is superseded by the
  1336 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1337 variant, even on a 64 bit machine.  The following example setting
  1338 prefers 64 bit if available:
  1339 
  1340   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1341 
  1342 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1343 Isabelle/Scala layer for advanced prover interaction and integration.
  1344 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1345 component.
  1346 
  1347 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1348 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1349 similar to the default assignment of the document preparation system
  1350 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1351 provides some operations for direct access to the font without asking
  1352 the user for manual installation.
  1353 
  1354 
  1355 
  1356 New in Isabelle2009-1 (December 2009)
  1357 -------------------------------------
  1358 
  1359 *** General ***
  1360 
  1361 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1362 one backslash should be used, even in ML sources.
  1363 
  1364 
  1365 *** Pure ***
  1366 
  1367 * Locale interpretation propagates mixins along the locale hierarchy.
  1368 The currently only available mixins are the equations used to map
  1369 local definitions to terms of the target domain of an interpretation.
  1370 
  1371 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1372 loc" to print all interpretations of locale "loc" in the theory.
  1373 Interpretations in proofs are not shown.
  1374 
  1375 * Thoroughly revised locales tutorial.  New section on conditional
  1376 interpretation.
  1377 
  1378 * On instantiation of classes, remaining undefined class parameters
  1379 are formally declared.  INCOMPATIBILITY.
  1380 
  1381 
  1382 *** Document preparation ***
  1383 
  1384 * New generalized style concept for printing terms: @{foo (style) ...}
  1385 instead of @{foo_style style ...}  (old form is still retained for
  1386 backward compatibility).  Styles can be also applied for
  1387 antiquotations prop, term_type and typeof.
  1388 
  1389 
  1390 *** HOL ***
  1391 
  1392 * New proof method "smt" for a combination of first-order logic with
  1393 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1394 fixed-size bitvectors; there is also basic support for higher-order
  1395 features (esp. lambda abstractions).  It is an incomplete decision
  1396 procedure based on external SMT solvers using the oracle mechanism;
  1397 for the SMT solver Z3, this method is proof-producing.  Certificates
  1398 are provided to avoid calling the external solvers solely for
  1399 re-checking proofs.  Due to a remote SMT service there is no need for
  1400 installing SMT solvers locally.  See src/HOL/SMT.
  1401 
  1402 * New commands to load and prove verification conditions generated by
  1403 the Boogie program verifier or derived systems (e.g. the Verifying C
  1404 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1405 
  1406 * New counterexample generator tool 'nitpick' based on the Kodkod
  1407 relational model finder.  See src/HOL/Tools/Nitpick and
  1408 src/HOL/Nitpick_Examples.
  1409 
  1410 * New commands 'code_pred' and 'values' to invoke the predicate
  1411 compiler and to enumerate values of inductive predicates.
  1412 
  1413 * A tabled implementation of the reflexive transitive closure.
  1414 
  1415 * New implementation of quickcheck uses generic code generator;
  1416 default generators are provided for all suitable HOL types, records
  1417 and datatypes.  Old quickcheck can be re-activated importing theory
  1418 Library/SML_Quickcheck.
  1419 
  1420 * New testing tool Mirabelle for automated proof tools.  Applies
  1421 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1422 every proof step in a theory.  To be used in batch mode via the
  1423 "mirabelle" utility.
  1424 
  1425 * New proof method "sos" (sum of squares) for nonlinear real
  1426 arithmetic (originally due to John Harison). It requires theory
  1427 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1428 works well in practice on quantifier-free real arithmetic with +, -,
  1429 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1430 inequalities between polynomials.  It makes use of external
  1431 semidefinite programming solvers.  Method "sos" generates a
  1432 certificate that can be pasted into the proof thus avoiding the need
  1433 to call an external tool every time the proof is checked.  See
  1434 src/HOL/Library/Sum_Of_Squares.
  1435 
  1436 * New method "linarith" invokes existing linear arithmetic decision
  1437 procedure only.
  1438 
  1439 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1440 
  1441 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1442 Causes full type information to be output to the ATPs.  This slows
  1443 ATPs down considerably but eliminates a source of unsound "proofs"
  1444 that fail later.
  1445 
  1446 * New method "metisFT": A version of metis that uses full type
  1447 information in order to avoid failures of proof reconstruction.
  1448 
  1449 * New evaluator "approximate" approximates an real valued term using
  1450 the same method as the approximation method.
  1451 
  1452 * Method "approximate" now supports arithmetic expressions as
  1453 boundaries of intervals and implements interval splitting and Taylor
  1454 series expansion.
  1455 
  1456 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1457 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1458 
  1459 * New theory SupInf of the supremum and infimum operators for sets of
  1460 reals.
  1461 
  1462 * New theory Probability, which contains a development of measure
  1463 theory, eventually leading to Lebesgue integration and probability.
  1464 
  1465 * Extended Multivariate Analysis to include derivation and Brouwer's
  1466 fixpoint theorem.
  1467 
  1468 * Reorganization of number theory, INCOMPATIBILITY:
  1469   - new number theory development for nat and int, in theories Divides
  1470     and GCD as well as in new session Number_Theory
  1471   - some constants and facts now suffixed with _nat and _int
  1472     accordingly
  1473   - former session NumberTheory now named Old_Number_Theory, including
  1474     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1475   - moved theory Pocklington from src/HOL/Library to
  1476     src/HOL/Old_Number_Theory
  1477 
  1478 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1479 lcm of finite and infinite sets. It is shown that they form a complete
  1480 lattice.
  1481 
  1482 * Class semiring_div requires superclass no_zero_divisors and proof of
  1483 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1484 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1485 generalized to class semiring_div, subsuming former theorems
  1486 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1487 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1488 INCOMPATIBILITY.
  1489 
  1490 * Refinements to lattice classes and sets:
  1491   - less default intro/elim rules in locale variant, more default
  1492     intro/elim rules in class variant: more uniformity
  1493   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1494     le_inf_iff
  1495   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1496     sup_aci)
  1497   - renamed ACI to inf_sup_aci
  1498   - new class "boolean_algebra"
  1499   - class "complete_lattice" moved to separate theory
  1500     "Complete_Lattice"; corresponding constants (and abbreviations)
  1501     renamed and with authentic syntax:
  1502     Set.Inf ~>    Complete_Lattice.Inf
  1503     Set.Sup ~>    Complete_Lattice.Sup
  1504     Set.INFI ~>   Complete_Lattice.INFI
  1505     Set.SUPR ~>   Complete_Lattice.SUPR
  1506     Set.Inter ~>  Complete_Lattice.Inter
  1507     Set.Union ~>  Complete_Lattice.Union
  1508     Set.INTER ~>  Complete_Lattice.INTER
  1509     Set.UNION ~>  Complete_Lattice.UNION
  1510   - authentic syntax for
  1511     Set.Pow
  1512     Set.image
  1513   - mere abbreviations:
  1514     Set.empty               (for bot)
  1515     Set.UNIV                (for top)
  1516     Set.inter               (for inf, formerly Set.Int)
  1517     Set.union               (for sup, formerly Set.Un)
  1518     Complete_Lattice.Inter  (for Inf)
  1519     Complete_Lattice.Union  (for Sup)
  1520     Complete_Lattice.INTER  (for INFI)
  1521     Complete_Lattice.UNION  (for SUPR)
  1522   - object-logic definitions as far as appropriate
  1523 
  1524 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1525 Un_subset_iff are explicitly deleted as default simp rules; then also
  1526 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1527 deleted to achieve the desired effect.
  1528 
  1529 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1530 rules by default any longer; the same applies to min_max.inf_absorb1
  1531 etc.  INCOMPATIBILITY.
  1532 
  1533 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1534 pred_set_conv by default.  INCOMPATIBILITY.
  1535 
  1536 * Power operations on relations and functions are now one dedicated
  1537 constant "compow" with infix syntax "^^".  Power operation on
  1538 multiplicative monoids retains syntax "^" and is now defined generic
  1539 in class power.  INCOMPATIBILITY.
  1540 
  1541 * Relation composition "R O S" now has a more standard argument order:
  1542 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1543 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1544 break, since the O_assoc rule was not rewritten like this.  Fix using
  1545 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1546 
  1547 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1548 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1549 INCOMPATIBILITY.
  1550 
  1551 * Most rules produced by inductive and datatype package have mandatory
  1552 prefixes.  INCOMPATIBILITY.
  1553 
  1554 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1555 the attribute of the same name.  Each of the theorems in the list
  1556 DERIV_intros assumes composition with an additional function and
  1557 matches a variable to the derivative, which has to be solved by the
  1558 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1559 of most elementary terms.  Former Maclauren.DERIV_tac and
  1560 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1561 INCOMPATIBILITY.
  1562 
  1563 * Code generator attributes follow the usual underscore convention:
  1564     code_unfold     replaces    code unfold
  1565     code_post       replaces    code post
  1566     etc.
  1567   INCOMPATIBILITY.
  1568 
  1569 * Renamed methods:
  1570     sizechange -> size_change
  1571     induct_scheme -> induction_schema
  1572   INCOMPATIBILITY.
  1573 
  1574 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1575 INCOMPATIBILITY, use "undefined" directly.
  1576 
  1577 * Renamed theorems:
  1578     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1579     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1580     Suc_plus1 -> Suc_eq_plus1
  1581     *anti_sym -> *antisym*
  1582     vector_less_eq_def -> vector_le_def
  1583   INCOMPATIBILITY.
  1584 
  1585 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1586 INCOMPATIBILITY.
  1587 
  1588 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1589 INCOMPATIBILITY.
  1590 
  1591 
  1592 *** HOLCF ***
  1593 
  1594 * Theory Representable defines a class "rep" of domains that are
  1595 representable (via an ep-pair) in the universal domain type "udom".
  1596 Instances are provided for all type constructors defined in HOLCF.
  1597 
  1598 * The 'new_domain' command is a purely definitional version of the
  1599 domain package, for representable domains.  Syntax is identical to the
  1600 old domain package.  The 'new_domain' package also supports indirect
  1601 recursion using previously-defined type constructors.  See
  1602 src/HOLCF/ex/New_Domain.thy for examples.
  1603 
  1604 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1605 on the left-hand side of an equation, and then performs
  1606 simplification.  Rewriting is done using rules declared with the
  1607 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1608 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1609 
  1610 * The pattern-match compiler in 'fixrec' can now handle constructors
  1611 with HOL function types.  Pattern-match combinators for the Pair
  1612 constructor are pre-configured.
  1613 
  1614 * The 'fixrec' package now produces better fixed-point induction rules
  1615 for mutually-recursive definitions:  Induction rules have conclusions
  1616 of the form "P foo bar" instead of "P <foo, bar>".
  1617 
  1618 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1619 been renamed to "below".  The name "below" now replaces "less" in many
  1620 theorem names.  (Legacy theorem names using "less" are still supported
  1621 as well.)
  1622 
  1623 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1624 patterns can be used to generate strictness rules, or to make
  1625 functions more strict (much like the bang-patterns supported by the
  1626 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1627 examples.
  1628 
  1629 
  1630 *** ML ***
  1631 
  1632 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1633 errors and run-time exceptions, including detailed source positions.
  1634 
  1635 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1636 identified entries, with some additional information such as source
  1637 position, logical grouping etc.
  1638 
  1639 * Theory and context data is now introduced by the simplified and
  1640 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1641 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1642 copy operation) is still available for some time.
  1643 
  1644 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1645 provides a high-level programming interface to synchronized state
  1646 variables with atomic update.  This works via pure function
  1647 application within a critical section -- its runtime should be as
  1648 short as possible; beware of deadlocks if critical code is nested,
  1649 either directly or indirectly via other synchronized variables!
  1650 
  1651 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1652 wraps raw ML references, explicitly indicating their non-thread-safe
  1653 behaviour.  The Isar toplevel keeps this structure open, to
  1654 accommodate Proof General as well as quick and dirty interactive
  1655 experiments with references.
  1656 
  1657 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1658 parallel tactical reasoning.
  1659 
  1660 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1661 are similar to SUBPROOF, but are slightly more flexible: only the
  1662 specified parts of the subgoal are imported into the context, and the
  1663 body tactic may introduce new subgoals and schematic variables.
  1664 
  1665 * Old tactical METAHYPS, which does not observe the proof context, has
  1666 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1667 or Subgoal.FOCUS etc.
  1668 
  1669 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1670 functors have their own ML name space there is no point to mark them
  1671 separately.)  Minor INCOMPATIBILITY.
  1672 
  1673 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1674 
  1675 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1676 INCOMPATIBILITY.
  1677 
  1678 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1679 mode, which avoids critical setmp.
  1680 
  1681 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1682 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1683 Attrib/Method.setup introduced in Isabelle2009.
  1684 
  1685 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1686 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1687 last resort.  INCOMPATIBILITY.
  1688 
  1689 * Display.pretty_thm now requires a proper context (cf. former
  1690 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1691 or even Display.pretty_thm_without_context as last resort.
  1692 INCOMPATIBILITY.
  1693 
  1694 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1695 Syntax.pretty_typ/term directly, preferably with proper context
  1696 instead of global theory.
  1697 
  1698 
  1699 *** System ***
  1700 
  1701 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1702 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1703 usedir option -q.
  1704 
  1705 * Support for additional "Isabelle components" via etc/components, see
  1706 also the system manual.
  1707 
  1708 * The isabelle makeall tool now operates on all components with
  1709 IsaMakefile, not just hardwired "logics".
  1710 
  1711 * Removed "compress" option from isabelle-process and isabelle usedir;
  1712 this is always enabled.
  1713 
  1714 * Discontinued support for Poly/ML 4.x versions.
  1715 
  1716 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1717 on a given logic image.  This requires the lighttpd webserver and is
  1718 currently supported on Linux only.
  1719 
  1720 
  1721 
  1722 New in Isabelle2009 (April 2009)
  1723 --------------------------------
  1724 
  1725 *** General ***
  1726 
  1727 * Simplified main Isabelle executables, with less surprises on
  1728 case-insensitive file-systems (such as Mac OS).
  1729 
  1730   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1731     "isatool."
  1732 
  1733   - The former "isabelle" alias for "isabelle-process" has been
  1734     removed (should rarely occur to regular users).
  1735 
  1736   - The former "isabelle-interface" and its alias "Isabelle" have been
  1737     removed (interfaces are now regular Isabelle tools).
  1738 
  1739 Within scripts and make files, the Isabelle environment variables
  1740 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1741 respectively.  (The latter are still available as legacy feature.)
  1742 
  1743 The old isabelle-interface wrapper could react in confusing ways if
  1744 the interface was uninstalled or changed otherwise.  Individual
  1745 interface tool configuration is now more explicit, see also the
  1746 Isabelle system manual.  In particular, Proof General is now available
  1747 via "isabelle emacs".
  1748 
  1749 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1750 purge installed copies of Isabelle executables and re-run "isabelle
  1751 install -p ...", or use symlinks.
  1752 
  1753 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1754 old ~/isabelle, which was slightly non-standard and apt to cause
  1755 surprises on case-insensitive file-systems (such as Mac OS).
  1756 
  1757 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1758 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1759 care is required when using older releases of Isabelle.  Note that
  1760 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1761 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1762 
  1763 * Proofs of fully specified statements are run in parallel on
  1764 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1765 a regular 4-core machine, if the initial heap space is made reasonably
  1766 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1767 
  1768 * The main reference manuals ("isar-ref", "implementation", and
  1769 "system") have been updated and extended.  Formally checked references
  1770 as hyperlinks are now available uniformly.
  1771 
  1772 
  1773 *** Pure ***
  1774 
  1775 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1776 respects.  The most important changes are listed below.  See the
  1777 Tutorial on Locales ("locales" manual) for details.
  1778 
  1779 - In locale expressions, instantiation replaces renaming.  Parameters
  1780 must be declared in a for clause.  To aid compatibility with previous
  1781 parameter inheritance, in locale declarations, parameters that are not
  1782 'touched' (instantiation position "_" or omitted) are implicitly added
  1783 with their syntax at the beginning of the for clause.
  1784 
  1785 - Syntax from abbreviations and definitions in locales is available in
  1786 locale expressions and context elements.  The latter is particularly
  1787 useful in locale declarations.
  1788 
  1789 - More flexible mechanisms to qualify names generated by locale
  1790 expressions.  Qualifiers (prefixes) may be specified in locale
  1791 expressions, and can be marked as mandatory (syntax: "name!:") or
  1792 optional (syntax "name?:").  The default depends for plain "name:"
  1793 depends on the situation where a locale expression is used: in
  1794 commands 'locale' and 'sublocale' prefixes are optional, in
  1795 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1796 implicit qualifiers derived from the parameter names of a locale are
  1797 no longer generated.
  1798 
  1799 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1800 instantiation clause in "interpretation" and "interpret" (square
  1801 brackets) is no longer available.  Use locale expressions.
  1802 
  1803 - When converting proof scripts, mandatory qualifiers in
  1804 'interpretation' and 'interpret' should be retained by default, even
  1805 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1806 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1807 in locale expressions range over a single locale instance only.
  1808 
  1809 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1810 In existing theorem specifications replace the includes element by the
  1811 respective context elements of the included locale, omitting those
  1812 that are already present in the theorem specification.  Multiple
  1813 assume elements of a locale should be replaced by a single one
  1814 involving the locale predicate.  In the proof body, declarations (most
  1815 notably theorems) may be regained by interpreting the respective
  1816 locales in the proof context as required (command "interpret").
  1817 
  1818 If using "includes" in replacement of a target solely because the
  1819 parameter types in the theorem are not as general as in the target,
  1820 consider declaring a new locale with additional type constraints on
  1821 the parameters (context element "constrains").
  1822 
  1823 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1824 
  1825 - Locale interpretation commands no longer attempt to simplify goal.
  1826 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1827 methods intro_locales and unfold_locales to clarify.
  1828 
  1829 - Locale interpretation commands no longer accept interpretation
  1830 attributes.  INCOMPATIBILITY.
  1831 
  1832 * Class declaration: so-called "base sort" must not be given in import
  1833 list any longer, but is inferred from the specification.  Particularly
  1834 in HOL, write
  1835 
  1836     class foo = ...
  1837 
  1838 instead of
  1839 
  1840     class foo = type + ...
  1841 
  1842 * Class target: global versions of theorems stemming do not carry a
  1843 parameter prefix any longer.  INCOMPATIBILITY.
  1844 
  1845 * Class 'instance' command no longer accepts attached definitions.
  1846 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1847 
  1848 * Recovered hiding of consts, which was accidentally broken in
  1849 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1850 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1851 
  1852 * Slightly more coherent Pure syntax, with updated documentation in
  1853 isar-ref manual.  Removed locales meta_term_syntax and
  1854 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1855 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1856 directly in regular applications.
  1857 
  1858 * There is a new syntactic category "float_const" for signed decimal
  1859 fractions (e.g. 123.45 or -123.45).
  1860 
  1861 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1862 interface with 'setup' command instead.
  1863 
  1864 * Command 'local_setup' is similar to 'setup', but operates on a local
  1865 theory context.
  1866 
  1867 * The 'axiomatization' command now only works within a global theory
  1868 context.  INCOMPATIBILITY.
  1869 
  1870 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1871 hypotheses.  Sorts required in the course of reasoning need to be
  1872 covered by the constraints in the initial statement, completed by the
  1873 type instance information of the background theory.  Non-trivial sort
  1874 hypotheses, which rarely occur in practice, may be specified via
  1875 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1876 
  1877   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1878 
  1879 The result contains an implicit sort hypotheses as before --
  1880 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1881 normalization.
  1882 
  1883 * Generalized Isar history, with support for linear undo, direct state
  1884 addressing etc.
  1885 
  1886 * Changed defaults for unify configuration options:
  1887 
  1888   unify_trace_bound = 50 (formerly 25)
  1889   unify_search_bound = 60 (formerly 30)
  1890 
  1891 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1892 
  1893   a) On theory merge, the last set of code equations for a particular
  1894      constant is taken (in accordance with the policy applied by other
  1895      parts of the code generator framework).
  1896 
  1897   b) Code equations stemming from explicit declarations (e.g. code
  1898      attribute) gain priority over default code equations stemming
  1899      from definition, primrec, fun etc.
  1900 
  1901 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1902 
  1903 * Unified theorem tables for both code generators.  Thus [code
  1904 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1905 
  1906 * Command 'find_consts' searches for constants based on type and name
  1907 patterns, e.g.
  1908 
  1909     find_consts "_ => bool"
  1910 
  1911 By default, matching is against subtypes, but it may be restricted to
  1912 the whole type.  Searching by name is possible.  Multiple queries are
  1913 conjunctive and queries may be negated by prefixing them with a
  1914 hyphen:
  1915 
  1916     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1917 
  1918 * New 'find_theorems' criterion "solves" matches theorems that
  1919 directly solve the current goal (modulo higher-order unification).
  1920 
  1921 * Auto solve feature for main theorem statements: whenever a new goal
  1922 is stated, "find_theorems solves" is called; any theorems that could
  1923 solve the lemma directly are listed as part of the goal state.
  1924 Cf. associated options in Proof General Isabelle settings menu,
  1925 enabled by default, with reasonable timeout for pathological cases of
  1926 higher-order unification.
  1927 
  1928 
  1929 *** Document preparation ***
  1930 
  1931 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1932 demanding keyword 'by' and supporting the full method expression
  1933 syntax just like the Isar command 'by'.
  1934 
  1935 
  1936 *** HOL ***
  1937 
  1938 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1939 points Main and Complex_Main remain as before.
  1940 
  1941 * Logic image HOL-Plain provides a minimal HOL with the most important
  1942 tools available (inductive, datatype, primrec, ...).  This facilitates
  1943 experimentation and tool development.  Note that user applications
  1944 (and library theories) should never refer to anything below theory
  1945 Main, as before.
  1946 
  1947 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1948 experimentation due to shorter build times.
  1949 
  1950 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1951 were previously part of former HOL-Complex.  Entry point Hyperreal
  1952 remains valid, but theories formerly using Complex_Main should now use
  1953 new entry point Hypercomplex.
  1954 
  1955 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1956 Posix processes.  Avoids potentially expensive forking of the ML
  1957 process.  New thread-based implementation also works on non-Unix
  1958 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1959 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1960 commands are covered in the isar-ref manual.
  1961 
  1962 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1963 sledgehammer without local ATP installation (Vampire etc.). Other
  1964 provers may be included via suitable ML wrappers, see also
  1965 src/HOL/ATP_Linkup.thy.
  1966 
  1967 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1968 menu.
  1969 
  1970 * The metis method no longer fails because the theorem is too trivial
  1971 (contains the empty clause).
  1972 
  1973 * The metis method now fails in the usual manner, rather than raising
  1974 an exception, if it determines that it cannot prove the theorem.
  1975 
  1976 * Method "coherent" implements a prover for coherent logic (see also
  1977 src/Tools/coherent.ML).
  1978 
  1979 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1980 "undefined" is the right choice to replace "arbitrary", though
  1981 logically there is no difference.  INCOMPATIBILITY.
  1982 
  1983 * Command "value" now integrates different evaluation mechanisms.  The
  1984 result of the first successful evaluation mechanism is printed.  In
  1985 square brackets a particular named evaluation mechanisms may be
  1986 specified (currently, [SML], [code] or [nbe]).  See further
  1987 src/HOL/ex/Eval_Examples.thy.
  1988 
  1989 * Normalization by evaluation now allows non-leftlinear equations.
  1990 Declare with attribute [code nbe].
  1991 
  1992 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1993 as the structured Isar versions "cases" and "induct", cf. the
  1994 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1995 are now presented as a list of individual projections
  1996 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1997 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1998 rare situations a different rule is selected --- notably nested tuple
  1999 elimination instead of former prod.exhaust: use explicit (case_tac t
  2000 rule: prod.exhaust) here.
  2001 
  2002 * Attributes "cases", "induct", "coinduct" support "del" option.
  2003 
  2004 * Removed fact "case_split_thm", which duplicates "case_split".
  2005 
  2006 * The option datatype has been moved to a new theory Option.  Renamed
  2007 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2008 
  2009 * New predicate "strict_mono" classifies strict functions on partial
  2010 orders.  With strict functions on linear orders, reasoning about
  2011 (in)equalities is facilitated by theorems "strict_mono_eq",
  2012 "strict_mono_less_eq" and "strict_mono_less".
  2013 
  2014 * Some set operations are now proper qualified constants with
  2015 authentic syntax.  INCOMPATIBILITY:
  2016 
  2017     op Int ~>   Set.Int
  2018     op Un ~>    Set.Un
  2019     INTER ~>    Set.INTER
  2020     UNION ~>    Set.UNION
  2021     Inter ~>    Set.Inter
  2022     Union ~>    Set.Union
  2023     {} ~>       Set.empty
  2024     UNIV ~>     Set.UNIV
  2025 
  2026 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2027 theory Set.
  2028 
  2029 * Auxiliary class "itself" has disappeared -- classes without any
  2030 parameter are treated as expected by the 'class' command.
  2031 
  2032 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2033 
  2034 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2035 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2036 
  2037 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2038 method "approximation".  It proves formulas on real values by using
  2039 interval arithmetic.  In the formulas are also the transcendental
  2040 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2041 allowed. For examples see
  2042 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2043 
  2044 * Theory "Reflection" now resides in HOL/Library.
  2045 
  2046 * Entry point to Word library now simply named "Word".
  2047 INCOMPATIBILITY.
  2048 
  2049 * Made source layout more coherent with logical distribution
  2050 structure:
  2051 
  2052     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2053     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2054     src/HOL/Library/GCD.thy ~> src/HOL/
  2055     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2056     src/HOL/Library/Parity.thy ~> src/HOL/
  2057     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2058     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2059     src/HOL/Real/Lubs.thy ~> src/HOL/
  2060     src/HOL/Real/PReal.thy ~> src/HOL/
  2061     src/HOL/Real/Rational.thy ~> src/HOL/
  2062     src/HOL/Real/RComplete.thy ~> src/HOL/
  2063     src/HOL/Real/RealDef.thy ~> src/HOL/
  2064     src/HOL/Real/RealPow.thy ~> src/HOL/
  2065     src/HOL/Real/Real.thy ~> src/HOL/
  2066     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2067     src/HOL/Complex/Complex.thy ~> src/HOL/
  2068     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2069     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2070     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2071     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2072     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2073     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2074     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2075     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2076     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2077     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2078     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2079     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2080     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2081     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2082     src/HOL/Real/Float ~> src/HOL/Library/
  2083     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2084     src/HOL/Real/RealVector.thy ~> src/HOL/
  2085 
  2086     src/HOL/arith_data.ML ~> src/HOL/Tools
  2087     src/HOL/hologic.ML ~> src/HOL/Tools
  2088     src/HOL/simpdata.ML ~> src/HOL/Tools
  2089     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2090     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2091     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2092     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2093     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2094     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2095     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2096 
  2097     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2098     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2099     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2100     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2101     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2102     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2103 
  2104 * If methods "eval" and "evaluation" encounter a structured proof
  2105 state with !!/==>, only the conclusion is evaluated to True (if
  2106 possible), avoiding strange error messages.
  2107 
  2108 * Method "sizechange" automates termination proofs using (a
  2109 modification of) the size-change principle.  Requires SAT solver.  See
  2110 src/HOL/ex/Termination.thy for examples.
  2111 
  2112 * Simplifier: simproc for let expressions now unfolds if bound
  2113 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2114 
  2115 * Method "arith": Linear arithmetic now ignores all inequalities when
  2116 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2117 
  2118 * New attribute "arith" for facts that should always be used
  2119 automatically by arithmetic. It is intended to be used locally in
  2120 proofs, e.g.
  2121 
  2122   assumes [arith]: "x > 0"
  2123 
  2124 Global usage is discouraged because of possible performance impact.
  2125 
  2126 * New classes "top" and "bot" with corresponding operations "top" and
  2127 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2128 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2129 
  2130 * Changed definition lemma "less_fun_def" in order to provide an
  2131 instance for preorders on functions; use lemma "less_le" instead.
  2132 INCOMPATIBILITY.
  2133 
  2134 * Theory Orderings: class "wellorder" moved here, with explicit
  2135 induction rule "less_induct" as assumption.  For instantiation of
  2136 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2137 INCOMPATIBILITY.
  2138 
  2139 * Theory Orderings: added class "preorder" as superclass of "order".
  2140 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2141 etc. slightly changed.  Some theorems named order_class.* now named
  2142 preorder_class.*.
  2143 
  2144 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2145 "diag" to "Id_on".
  2146 
  2147 * Theory Finite_Set: added a new fold combinator of type
  2148 
  2149   ('a => 'b => 'b) => 'b => 'a set => 'b
  2150 
  2151 Occasionally this is more convenient than the old fold combinator
  2152 which is now defined in terms of the new one and renamed to
  2153 fold_image.
  2154 
  2155 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2156 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2157 extended with further lemmas!).  At the moment both still exist but
  2158 the former will disappear at some point.
  2159 
  2160 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2161 class recpower.  Type-specific simp rules for various recpower types
  2162 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2163 
  2164 rat_power_0    -> power_0
  2165 rat_power_Suc  -> power_Suc
  2166 realpow_0      -> power_0
  2167 realpow_Suc    -> power_Suc
  2168 complexpow_0   -> power_0
  2169 complexpow_Suc -> power_Suc
  2170 power_poly_0   -> power_0
  2171 power_poly_Suc -> power_Suc
  2172 
  2173 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2174 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2175 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2176 of lemmas from Divides has been generalized from nat to class
  2177 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2178 renames resulting from duplicate elimination:
  2179 
  2180     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2181     zero_dvd_iff ~>         dvd_0_left_iff
  2182     dvd_0 ~>                dvd_0_right
  2183     DIVISION_BY_ZERO_DIV ~> div_by_0
  2184     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2185     mult_div ~>             div_mult_self2_is_id
  2186     mult_mod ~>             mod_mult_self2_is_0
  2187 
  2188 * Theory IntDiv: removed many lemmas that are instances of class-based
  2189 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2190 rename old lemmas as follows:
  2191 
  2192 dvd_diff               -> nat_dvd_diff
  2193 dvd_zminus_iff         -> dvd_minus_iff
  2194 mod_add1_eq            -> mod_add_eq
  2195 mod_mult1_eq           -> mod_mult_right_eq
  2196 mod_mult1_eq'          -> mod_mult_left_eq
  2197 mod_mult_distrib_mod   -> mod_mult_eq
  2198 nat_mod_add_left_eq    -> mod_add_left_eq
  2199 nat_mod_add_right_eq   -> mod_add_right_eq
  2200 nat_mod_div_trivial    -> mod_div_trivial
  2201 nat_mod_mod_trivial    -> mod_mod_trivial
  2202 zdiv_zadd_self1        -> div_add_self1
  2203 zdiv_zadd_self2        -> div_add_self2
  2204 zdiv_zmult_self1       -> div_mult_self2_is_id
  2205 zdiv_zmult_self2       -> div_mult_self1_is_id
  2206 zdvd_triv_left         -> dvd_triv_left
  2207 zdvd_triv_right        -> dvd_triv_right
  2208 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2209 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2210 zmod_zadd_left_eq      -> mod_add_left_eq
  2211 zmod_zadd_right_eq     -> mod_add_right_eq
  2212 zmod_zadd_self1        -> mod_add_self1
  2213 zmod_zadd_self2        -> mod_add_self2
  2214 zmod_zadd1_eq          -> mod_add_eq
  2215 zmod_zdiff1_eq         -> mod_diff_eq
  2216 zmod_zdvd_zmod         -> mod_mod_cancel
  2217 zmod_zmod_cancel       -> mod_mod_cancel
  2218 zmod_zmult_self1       -> mod_mult_self2_is_0
  2219 zmod_zmult_self2       -> mod_mult_self1_is_0
  2220 zmod_1                 -> mod_by_1
  2221 zdiv_1                 -> div_by_1
  2222 zdvd_abs1              -> abs_dvd_iff
  2223 zdvd_abs2              -> dvd_abs_iff
  2224 zdvd_refl              -> dvd_refl
  2225 zdvd_trans             -> dvd_trans
  2226 zdvd_zadd              -> dvd_add
  2227 zdvd_zdiff             -> dvd_diff
  2228 zdvd_zminus_iff        -> dvd_minus_iff
  2229 zdvd_zminus2_iff       -> minus_dvd_iff
  2230 zdvd_zmultD            -> dvd_mult_right
  2231 zdvd_zmultD2           -> dvd_mult_left
  2232 zdvd_zmult_mono        -> mult_dvd_mono
  2233 zdvd_0_right           -> dvd_0_right
  2234 zdvd_0_left            -> dvd_0_left_iff
  2235 zdvd_1_left            -> one_dvd
  2236 zminus_dvd_iff         -> minus_dvd_iff
  2237 
  2238 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2239 
  2240 * The real numbers offer decimal input syntax: 12.34 is translated
  2241 into 1234/10^2. This translation is not reversed upon output.
  2242 
  2243 * Theory Library/Polynomial defines an abstract type 'a poly of
  2244 univariate polynomials with coefficients of type 'a.  In addition to
  2245 the standard ring operations, it also supports div and mod.  Code
  2246 generation is also supported, using list-style constructors.
  2247 
  2248 * Theory Library/Inner_Product defines a class of real_inner for real
  2249 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2250 => real.  Class real_inner is a subclass of real_normed_vector from
  2251 theory RealVector.
  2252 
  2253 * Theory Library/Product_Vector provides instances for the product
  2254 type 'a * 'b of several classes from RealVector and Inner_Product.
  2255 Definitions of addition, subtraction, scalar multiplication, norms,
  2256 and inner products are included.
  2257 
  2258 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2259 addition to the field operations, numerals and case syntax are also
  2260 supported.
  2261 
  2262 * Theory Library/Diagonalize provides constructive version of Cantor's
  2263 first diagonalization argument.
  2264 
  2265 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2266 zlcm (for int); carried together from various gcd/lcm developements in
  2267 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2268 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2269 may recover tupled syntax as follows:
  2270 
  2271     hide (open) const gcd
  2272     abbreviation gcd where
  2273       "gcd == (%(a, b). GCD.gcd a b)"
  2274     notation (output)
  2275       GCD.gcd ("gcd '(_, _')")
  2276 
  2277 The same works for lcm, zgcd, zlcm.
  2278 
  2279 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2280 instantiations for algebraic structures.  Removed some duplicate
  2281 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2282 
  2283 * ML antiquotation @{code} takes a constant as argument and generates
  2284 corresponding code in background and inserts name of the corresponding
  2285 resulting ML value/function/datatype constructor binding in place.
  2286 All occurrences of @{code} with a single ML block are generated
  2287 simultaneously.  Provides a generic and safe interface for
  2288 instrumentalizing code generation.  See
  2289 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2290 In future you ought to refrain from ad-hoc compiling generated SML
  2291 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2292 cannot refer to constants for which user-defined serializations are
  2293 set.  Refer to the corresponding ML counterpart directly in that
  2294 cases.
  2295 
  2296 * Command 'rep_datatype': instead of theorem names the command now
  2297 takes a list of terms denoting the constructors of the type to be
  2298 represented as datatype.  The characteristic theorems have to be
  2299 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2300 have disappeared in favour of existing ones:
  2301 
  2302     unit_induct                 ~> unit.induct
  2303     prod_induct                 ~> prod.induct
  2304     sum_induct                  ~> sum.induct
  2305     Suc_Suc_eq                  ~> nat.inject
  2306     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2307 
  2308 
  2309 *** HOL-Algebra ***
  2310 
  2311 * New locales for orders and lattices where the equivalence relation
  2312 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2313 locales use a record structure with field eq for the equivalence.
  2314 
  2315 * New theory of factorial domains.
  2316 
  2317 * Units_l_inv and Units_r_inv are now simp rules by default.
  2318 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2319 and/or r_inv will now also require deletion of these lemmas.
  2320 
  2321 * Renamed the following theorems, INCOMPATIBILITY:
  2322 
  2323 UpperD ~> Upper_memD
  2324 LowerD ~> Lower_memD
  2325 least_carrier ~> least_closed
  2326 greatest_carrier ~> greatest_closed
  2327 greatest_Lower_above ~> greatest_Lower_below
  2328 one_zero ~> carrier_one_zero
  2329 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2330 
  2331 
  2332 *** HOL-Nominal ***
  2333 
  2334 * Nominal datatypes can now contain type-variables.
  2335 
  2336 * Commands 'nominal_inductive' and 'equivariance' work with local
  2337 theory targets.
  2338 
  2339 * Nominal primrec can now works with local theory targets and its
  2340 specification syntax now conforms to the general format as seen in
  2341 'inductive' etc.
  2342 
  2343 * Method "perm_simp" honours the standard simplifier attributes
  2344 (no_asm), (no_asm_use) etc.
  2345 
  2346 * The new predicate #* is defined like freshness, except that on the
  2347 left hand side can be a set or list of atoms.
  2348 
  2349 * Experimental command 'nominal_inductive2' derives strong induction
  2350 principles for inductive definitions.  In contrast to
  2351 'nominal_inductive', which can only deal with a fixed number of
  2352 binders, it can deal with arbitrary expressions standing for sets of
  2353 atoms to be avoided.  The only inductive definition we have at the
  2354 moment that needs this generalisation is the typing rule for Lets in
  2355 the algorithm W:
  2356 
  2357  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2358  -----------------------------------------------------------------
  2359          Gamma |- Let x be t1 in t2 : T2
  2360 
  2361 In this rule one wants to avoid all the binders that are introduced by
  2362 "close Gamma T1".  We are looking for other examples where this
  2363 feature might be useful.  Please let us know.
  2364 
  2365 
  2366 *** HOLCF ***
  2367 
  2368 * Reimplemented the simplification procedure for proving continuity
  2369 subgoals.  The new simproc is extensible; users can declare additional
  2370 continuity introduction rules with the attribute [cont2cont].
  2371 
  2372 * The continuity simproc now uses a different introduction rule for
  2373 solving continuity subgoals on terms with lambda abstractions.  In
  2374 some rare cases the new simproc may fail to solve subgoals that the
  2375 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2376 Potential INCOMPATIBILITY.
  2377 
  2378 * Command 'fixrec': specification syntax now conforms to the general
  2379 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2380 examples.  INCOMPATIBILITY.
  2381 
  2382 
  2383 *** ZF ***
  2384 
  2385 * Proof of Zorn's Lemma for partial orders.
  2386 
  2387 
  2388 *** ML ***
  2389 
  2390 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2391 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2392 depends on multithreading, so timouts will not work before Poly/ML
  2393 5.2.1!
  2394 
  2395 * High-level support for concurrent ML programming, see
  2396 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2397 particularly convenient to organize independent functional
  2398 computations.  The concept of "synchronized variables" provides a
  2399 higher-order interface for components with shared state, avoiding the
  2400 delicate details of mutexes and condition variables.  (Requires
  2401 Poly/ML 5.2.1 or later.)
  2402 
  2403 * ML bindings produced via Isar commands are stored within the Isar
  2404 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2405 become thread-safe and work with undo as expected (concerning
  2406 top-level bindings, not side-effects on global references).
  2407 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2408 compiler at runtime; really global bindings need to be given outside a
  2409 theory.  (Requires Poly/ML 5.2 or later.)
  2410 
  2411 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2412 context.  Top-level ML bindings are stored within the proof context in
  2413 a purely sequential fashion, disregarding the nested proof structure.
  2414 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2415 proof.  (Requires Poly/ML 5.2 or later.)
  2416 
  2417 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2418 and Method.setup, as well as Isar commands 'attribute_setup' and
  2419 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2420 existing code accordingly, or use plain 'setup' together with old
  2421 Method.add_method.
  2422 
  2423 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2424 to 'a -> thm, while results are always tagged with an authentic oracle
  2425 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2426 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2427 accordingly.  Note that extra performance may be gained by producing
  2428 the cterm carefully, avoiding slow Thm.cterm_of.
  2429 
  2430 * Simplified interface for defining document antiquotations via
  2431 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2432 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2433 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2434 examples.
  2435 
  2436 * More systematic treatment of long names, abstract name bindings, and
  2437 name space operations.  Basic operations on qualified names have been
  2438 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2439 Long_Name.append.  Old type bstring has been mostly replaced by
  2440 abstract type binding (see structure Binding), which supports precise
  2441 qualification by packages and local theory targets, as well as proper
  2442 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2443 bstring values into Binding.name, or better pass through abstract
  2444 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2445 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2446 
  2447 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2448 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2449 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2450 
  2451 * Disposed old type and term read functions (Sign.read_def_typ,
  2452 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2453 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2454 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2455 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2456 resort for legacy applications.
  2457 
  2458 * Disposed old declarations, tactics, tactic combinators that refer to
  2459 the simpset or claset of an implicit theory (such as Addsimps,
  2460 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2461 embedded ML text, or local_simpset_of with a proper context passed as
  2462 explicit runtime argument.
  2463 
  2464 * Rules and tactics that read instantiations (read_instantiate,
  2465 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2466 context, which is required for parsing and type-checking.  Moreover,
  2467 the variables are specified as plain indexnames, not string encodings
  2468 thereof.  INCOMPATIBILITY.
  2469 
  2470 * Generic Toplevel.add_hook interface allows to analyze the result of
  2471 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2472 for theorem dependency output of transactions resulting in a new
  2473 theory state.
  2474 
  2475 * ML antiquotations: block-structured compilation context indicated by
  2476 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2477 
  2478   @{binding name}                         - basic name binding
  2479   @{let ?pat = term}                      - term abbreviation (HO matching)
  2480   @{note name = fact}                     - fact abbreviation
  2481   @{thm fact}                             - singleton fact (with attributes)
  2482   @{thms fact}                            - general fact (with attributes)
  2483   @{lemma prop by method}                 - singleton goal
  2484   @{lemma prop by meth1 meth2}            - singleton goal
  2485   @{lemma prop1 ... propN by method}      - general goal
  2486   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2487   @{lemma (open) ...}                     - open derivation
  2488 
  2489 
  2490 *** System ***
  2491 
  2492 * The Isabelle "emacs" tool provides a specific interface to invoke
  2493 Proof General / Emacs, with more explicit failure if that is not
  2494 installed (the old isabelle-interface script silently falls back on
  2495 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2496 installation location of the Proof General distribution.
  2497 
  2498 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2499 the Isabelle process into a JVM/Scala application.  See
  2500 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2501 process wrapper has been discontinued.)
  2502 
  2503 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2504 
  2505 * Various status messages (with exact source position information) are
  2506 emitted, if proper markup print mode is enabled.  This allows
  2507 user-interface components to provide detailed feedback on internal
  2508 prover operations.
  2509 
  2510 
  2511 
  2512 New in Isabelle2008 (June 2008)
  2513 -------------------------------
  2514 
  2515 *** General ***
  2516 
  2517 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2518 and updated, with formally checked references as hyperlinks.
  2519 
  2520 * Theory loader: use_thy (and similar operations) no longer set the
  2521 implicit ML context, which was occasionally hard to predict and in
  2522 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2523 provides a proper context already.
  2524 
  2525 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2526 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2527 'use' within a theory file will do the job.
  2528 
  2529 * Name space merge now observes canonical order, i.e. the second space
  2530 is inserted into the first one, while existing entries in the first
  2531 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2532 swap theory imports.
  2533 
  2534 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2535 INCOMPATIBILITY in identifier syntax etc.
  2536 
  2537 * Outer syntax: string tokens no longer admit escaped white space,
  2538 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2539 white space without escapes.
  2540 
  2541 * Outer syntax: string tokens may contain arbitrary character codes
  2542 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2543 "foo_bar".
  2544 
  2545 
  2546 *** Pure ***
  2547 
  2548 * Context-dependent token translations.  Default setup reverts locally
  2549 fixed variables, and adds hilite markup for undeclared frees.
  2550 
  2551 * Unused theorems can be found using the new command 'unused_thms'.
  2552 There are three ways of invoking it:
  2553 
  2554 (1) unused_thms
  2555      Only finds unused theorems in the current theory.
  2556 
  2557 (2) unused_thms thy_1 ... thy_n -
  2558      Finds unused theorems in the current theory and all of its ancestors,
  2559      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2560 
  2561 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2562      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2563      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2564      their ancestors.
  2565 
  2566 In order to increase the readability of the list produced by
  2567 unused_thms, theorems that have been created by a particular instance
  2568 of a theory command such as 'inductive' or 'function' are considered
  2569 to belong to the same "group", meaning that if at least one theorem in
  2570 this group is used, the other theorems in the same group are no longer
  2571 reported as unused.  Moreover, if all theorems in the group are
  2572 unused, only one theorem in the group is displayed.
  2573 
  2574 Note that proof objects have to be switched on in order for
  2575 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2576 usually the case when using Proof General with the default settings).
  2577 
  2578 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2579 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2580 duplicate fact bindings, or even accidental fact duplications.  Note
  2581 that tools may maintain dynamically scoped facts systematically, using
  2582 PureThy.add_thms_dynamic.
  2583 
  2584 * Command 'hide' now allows to hide from "fact" name space as well.
  2585 
  2586 * Eliminated destructive theorem database, simpset, claset, and
  2587 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2588 update of theories within ML code.
  2589 
  2590 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2591 INCOMPATIBILITY, object-logics depending on former Pure require
  2592 additional setup PureThy.old_appl_syntax_setup; object-logics
  2593 depending on former CPure need to refer to Pure.
  2594 
  2595 * Commands 'use' and 'ML' are now purely functional, operating on
  2596 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2597 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2598 INCOMPATIBILITY.
  2599 
  2600 * Command 'setup': discontinued implicit version with ML reference.
  2601 
  2602 * Instantiation target allows for simultaneous specification of class
  2603 instance operations together with an instantiation proof.
  2604 Type-checking phase allows to refer to class operations uniformly.
  2605 See src/HOL/Complex/Complex.thy for an Isar example and
  2606 src/HOL/Library/Eval.thy for an ML example.
  2607 
  2608 * Indexing of literal facts: be more serious about including only
  2609 facts from the visible specification/proof context, but not the
  2610 background context (locale etc.).  Affects `prop` notation and method
  2611 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2612 situations.
  2613 
  2614 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2615 "(open)" option, which used to expose internal bound variables to the
  2616 proof text.
  2617 
  2618 * Isar statements: removed obsolete case "rule_context".
  2619 INCOMPATIBILITY, better use explicit fixes/assumes.
  2620 
  2621 * Locale proofs: default proof step now includes 'unfold_locales';
  2622 hence 'proof' without argument may be used to unfold locale
  2623 predicates.
  2624 
  2625 
  2626 *** Document preparation ***
  2627 
  2628 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2629 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2630 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2631 spot); renamed link color from "darkblue" to "linkcolor" (default
  2632 value unchanged, can be redefined via \definecolor); no longer sets
  2633 "a4paper" option (unnecessary or even intrusive).
  2634 
  2635 * Antiquotation @{lemma A method} proves proposition A by the given
  2636 method (either a method name or a method name plus (optional) method
  2637 arguments in parentheses) and prints A just like @{prop A}.
  2638 
  2639 
  2640 *** HOL ***
  2641 
  2642 * New primrec package.  Specification syntax conforms in style to
  2643 definition/function/....  No separate induction rule is provided.  The
  2644 "primrec" command distinguishes old-style and new-style specifications
  2645 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2646 When adjusting theories, beware: constants stemming from new-style
  2647 primrec specifications have authentic syntax.
  2648 
  2649 * Metis prover is now an order of magnitude faster, and also works
  2650 with multithreading.
  2651 
  2652 * Metis: the maximum number of clauses that can be produced from a
  2653 theorem is now given by the attribute max_clauses.  Theorems that
  2654 exceed this number are ignored, with a warning printed.
  2655 
  2656 * Sledgehammer no longer produces structured proofs by default. To
  2657 enable, declare [[sledgehammer_full = true]].  Attributes
  2658 reconstruction_modulus, reconstruction_sorts renamed
  2659 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2660 
  2661 * Method "induct_scheme" derives user-specified induction rules
  2662 from well-founded induction and completeness of patterns. This factors
  2663 out some operations that are done internally by the function package
  2664 and makes them available separately.  See
  2665 src/HOL/ex/Induction_Scheme.thy for examples.
  2666 
  2667 * More flexible generation of measure functions for termination
  2668 proofs: Measure functions can be declared by proving a rule of the
  2669 form "is_measure f" and giving it the [measure_function] attribute.
  2670 The "is_measure" predicate is logically meaningless (always true), and
  2671 just guides the heuristic.  To find suitable measure functions, the
  2672 termination prover sets up the goal "is_measure ?f" of the appropriate
  2673 type and generates all solutions by prolog-style backwards proof using
  2674 the declared rules.
  2675 
  2676 This setup also deals with rules like 
  2677 
  2678   "is_measure f ==> is_measure (list_size f)"
  2679 
  2680 which accommodates nested datatypes that recurse through lists.
  2681 Similar rules are predeclared for products and option types.
  2682 
  2683 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2684 
  2685   INCOMPATIBILITIES:
  2686 
  2687   - Definitions of overloaded constants on sets have to be replaced by
  2688     definitions on => and bool.
  2689 
  2690   - Some definitions of overloaded operators on sets can now be proved
  2691     using the definitions of the operators on => and bool.  Therefore,
  2692     the following theorems have been renamed:
  2693 
  2694       subset_def   -> subset_eq
  2695       psubset_def  -> psubset_eq
  2696       set_diff_def -> set_diff_eq
  2697       Compl_def    -> Compl_eq
  2698       Sup_set_def  -> Sup_set_eq
  2699       Inf_set_def  -> Inf_set_eq
  2700       sup_set_def  -> sup_set_eq
  2701       inf_set_def  -> inf_set_eq
  2702 
  2703   - Due to the incompleteness of the HO unification algorithm, some
  2704     rules such as subst may require manual instantiation, if some of
  2705     the unknowns in the rule is a set.
  2706 
  2707   - Higher order unification and forward proofs:
  2708     The proof pattern
  2709 
  2710       have "P (S::'a set)" <...>
  2711       then have "EX S. P S" ..
  2712 
  2713     no longer works (due to the incompleteness of the HO unification
  2714     algorithm) and must be replaced by the pattern
  2715 
  2716       have "EX S. P S"
  2717       proof
  2718         show "P S" <...>
  2719       qed
  2720 
  2721   - Calculational reasoning with subst (or similar rules):
  2722     The proof pattern
  2723 
  2724       have "P (S::'a set)" <...>
  2725       also have "S = T" <...>
  2726       finally have "P T" .
  2727 
  2728     no longer works (for similar reasons as the previous example) and
  2729     must be replaced by something like
  2730 
  2731       have "P (S::'a set)" <...>
  2732       moreover have "S = T" <...>
  2733       ultimately have "P T" by simp
  2734 
  2735   - Tactics or packages written in ML code:
  2736     Code performing pattern matching on types via
  2737 
  2738       Type ("set", [T]) => ...
  2739 
  2740     must be rewritten. Moreover, functions like strip_type or
  2741     binder_types no longer return the right value when applied to a
  2742     type of the form
  2743 
  2744       T1 => ... => Tn => U => bool
  2745 
  2746     rather than
  2747 
  2748       T1 => ... => Tn => U set
  2749 
  2750 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2751 Wellfounded_Relations to theory Wellfounded.
  2752 
  2753 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2754 
  2755 * Class finite no longer treats UNIV as class parameter.  Use class
  2756 enum from theory Library/Enum instead to achieve a similar effect.
  2757 INCOMPATIBILITY.
  2758 
  2759 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2760 and "Cons".  INCOMPATIBILITY.
  2761 
  2762 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2763 Potential INCOMPATIBILITY.
  2764 
  2765 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2766 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2767 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2768 
  2769 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2770 the same name in theory Orderings:
  2771 
  2772   less_trans
  2773   less_linear
  2774   le_imp_less_or_eq
  2775   le_less_trans
  2776   less_le_trans
  2777   less_not_sym
  2778   less_asym
  2779 
  2780 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2781 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2782 and different variable names.
  2783 
  2784 * Library/Option_ord.thy: Canonical order on option type.
  2785 
  2786 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2787 finite maps.
  2788 
  2789 * Library/Countable.thy: Type class for countable types.
  2790 
  2791 * Theory Int: The representation of numerals has changed.  The infix
  2792 operator BIT and the bit datatype with constructors B0 and B1 have
  2793 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2794 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2795 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2796 accordingly.
  2797 
  2798 * Theory Nat: definition of <= and < on natural numbers no longer
  2799 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2800 le_def and less_def have disappeared.  Consider lemmas not_less
  2801 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2802 
  2803 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2804 (whose purpose mainly is for various fold_set functionals) have been
  2805 abandoned in favor of the existing algebraic classes
  2806 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2807 lower_semilattice (resp. upper_semilattice) and linorder.
  2808 INCOMPATIBILITY.
  2809 
  2810 * Theory Transitive_Closure: induct and cases rules now declare proper
  2811 case_names ("base" and "step").  INCOMPATIBILITY.
  2812 
  2813 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2814 lattices.  The form set-specific version is available as
  2815 Inductive.lfp_ordinal_induct_set.
  2816 
  2817 * Renamed theorems "power.simps" to "power_int.simps".
  2818 INCOMPATIBILITY.
  2819 
  2820 * Class semiring_div provides basic abstract properties of semirings
  2821 with division and modulo operations.  Subsumes former class dvd_mod.
  2822 
  2823 * Merged theories IntDef, Numeral and IntArith into unified theory
  2824 Int.  INCOMPATIBILITY.
  2825 
  2826 * Theory Library/Code_Index: type "index" now represents natural
  2827 numbers rather than integers.  INCOMPATIBILITY.
  2828 
  2829 * New class "uminus" with operation "uminus" (split of from class
  2830 "minus" which now only has operation "minus", binary).
  2831 INCOMPATIBILITY.
  2832 
  2833 * Constants "card", "internal_split", "option_map" now with authentic
  2834 syntax.  INCOMPATIBILITY.
  2835 
  2836 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2837 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2838 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2839 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2840 Sup_set_def, le_def, less_def, option_map_def now with object
  2841 equality.  INCOMPATIBILITY.
  2842 
  2843 * Records. Removed K_record, and replaced it by pure lambda term
  2844 %x. c. The simplifier setup is now more robust against eta expansion.
  2845 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2846 
  2847 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2848 
  2849 * Library/ListVector: new theory of arithmetic vector operations.
  2850 
  2851 * Library/Order_Relation: new theory of various orderings as sets of
  2852 pairs.  Defines preorders, partial orders, linear orders and
  2853 well-orders on sets and on types.
  2854 
  2855 
  2856 *** ZF ***
  2857 
  2858 * Renamed some theories to allow to loading both ZF and HOL in the
  2859 same session:
  2860 
  2861   Datatype  -> Datatype_ZF
  2862   Inductive -> Inductive_ZF
  2863   Int       -> Int_ZF
  2864   IntDiv    -> IntDiv_ZF
  2865   Nat       -> Nat_ZF
  2866   List      -> List_ZF
  2867   Main      -> Main_ZF
  2868 
  2869 INCOMPATIBILITY: ZF theories that import individual theories below
  2870 Main might need to be adapted.  Regular theory Main is still
  2871 available, as trivial extension of Main_ZF.
  2872 
  2873 
  2874 *** ML ***
  2875 
  2876 * ML within Isar: antiquotation @{const name} or @{const
  2877 name(typargs)} produces statically-checked Const term.
  2878 
  2879 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2880 (of the same name).  Removed obsolete print command.
  2881 
  2882 * Removed obsolete "use_legacy_bindings" function.
  2883 
  2884 * The ``print mode'' is now a thread-local value derived from a global
  2885 template (the former print_mode reference), thus access becomes
  2886 non-critical.  The global print_mode reference is for session
  2887 management only; user-code should use print_mode_value,
  2888 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2889 
  2890 * Functions system/system_out provide a robust way to invoke external
  2891 shell commands, with propagation of interrupts (requires Poly/ML
  2892 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2893 
  2894 
  2895 *** System ***
  2896 
  2897 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2898 in accordance with Proof General 3.7, which prefers GNU emacs.
  2899 
  2900 * isatool tty runs Isabelle process with plain tty interaction;
  2901 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2902 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2903 
  2904 * isatool browser now works with Cygwin as well, using general
  2905 "javapath" function defined in Isabelle process environment.
  2906 
  2907 * YXML notation provides a simple and efficient alternative to
  2908 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2909 isatool yxml as described in the Isabelle system manual.
  2910 
  2911 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2912 provides general wrapper for managing an Isabelle process in a robust
  2913 fashion, with ``cooked'' output from stdin/stderr.
  2914 
  2915 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2916 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2917 
  2918 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2919 way of changing the user's settings is via
  2920 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2921 script.
  2922 
  2923 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2924 cores of the underlying machine, which is a good starting point for
  2925 optimal performance tuning.  The corresponding usedir option -M allows
  2926 "max" as an alias for "0".  WARNING: does not work on certain versions
  2927 of Mac OS (with Poly/ML 5.1).
  2928 
  2929 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2930 adverse effect of Isabelle flooding interactive front-ends (notably
  2931 ProofGeneral / XEmacs).
  2932 
  2933 
  2934 
  2935 New in Isabelle2007 (November 2007)
  2936 -----------------------------------
  2937 
  2938 *** General ***
  2939 
  2940 * More uniform information about legacy features, notably a
  2941 warning/error of "Legacy feature: ...", depending on the state of the
  2942 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2943 legacy features will disappear eventually.
  2944 
  2945 * Theory syntax: the header format ``theory A = B + C:'' has been
  2946 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2947 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2948 
  2949 * Theory syntax: the old non-Isar theory file format has been
  2950 discontinued altogether.  Note that ML proof scripts may still be used
  2951 with Isar theories; migration is usually quite simple with the ML
  2952 function use_legacy_bindings.  INCOMPATIBILITY.
  2953 
  2954 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2955 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2956 quotes.
  2957 
  2958 * Theory loader: be more serious about observing the static theory
  2959 header specifications (including optional directories), but not the
  2960 accidental file locations of previously successful loads.  The strict
  2961 update policy of former update_thy is now already performed by
  2962 use_thy, so the former has been removed; use_thys updates several
  2963 theories simultaneously, just as 'imports' within a theory header
  2964 specification, but without merging the results.  Potential
  2965 INCOMPATIBILITY: may need to refine theory headers and commands
  2966 ROOT.ML which depend on load order.
  2967 
  2968 * Theory loader: optional support for content-based file
  2969 identification, instead of the traditional scheme of full physical
  2970 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2971 (cf. the system manual).  The new scheme allows to work with
  2972 non-finished theories in persistent session images, such that source
  2973 files may be moved later on without requiring reloads.
  2974 
  2975 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2976 file (with the same base name as the theory) are considered a legacy
  2977 feature, which will disappear eventually. Even now, the theory loader
  2978 no longer maintains dependencies on such files.
  2979 
  2980 * Syntax: the scope for resolving ambiguities via type-inference is
  2981 now limited to individual terms, instead of whole simultaneous
  2982 specifications as before. This greatly reduces the complexity of the
  2983 syntax module and improves flexibility by separating parsing and
  2984 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2985 'fixes' etc.) are required in rare situations.
  2986 
  2987 * Syntax: constants introduced by new-style packages ('definition',
  2988 'abbreviation' etc.) are passed through the syntax module in
  2989 ``authentic mode''. This means that associated mixfix annotations
  2990 really stick to such constants, independently of potential name space
  2991 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2992 trees are represented slightly differently, may need to adapt syntax
  2993 translations accordingly. Use CONST marker in 'translations' and
  2994 @{const_syntax} antiquotation in 'parse_translation' etc.
  2995 
  2996 * Legacy goal package: reduced interface to the bare minimum required
  2997 to keep existing proof scripts running.  Most other user-level
  2998 functions are now part of the OldGoals structure, which is *not* open
  2999 by default (consider isatool expandshort before open OldGoals).
  3000 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3001 these tend to cause confusion about the actual goal (!) context being
  3002 used here, which is not necessarily the same as the_context().
  3003 
  3004 * Command 'find_theorems': supports "*" wild-card in "name:"
  3005 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3006 support a specific search form (see ProofGeneral/CHANGES).
  3007 
  3008 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3009 by default, which means that "prems" (and also "fixed variables") are
  3010 suppressed from proof state output.  Note that the ProofGeneral
  3011 settings mechanism allows to change and save options persistently, but
  3012 older versions of Isabelle will fail to start up if a negative prems
  3013 limit is imposed.
  3014 
  3015 * Local theory targets may be specified by non-nested blocks of
  3016 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3017 contain definitions, theorems etc., including any derived mechanism
  3018 that has been implemented on top of these primitives.  This concept
  3019 generalizes the existing ``theorem (in ...)'' towards more versatility
  3020 and scalability.
  3021 
  3022 * Proof General interface: proper undo of final 'end' command;
  3023 discontinued Isabelle/classic mode (ML proof scripts).
  3024 
  3025 
  3026 *** Document preparation ***
  3027 
  3028 * Added antiquotation @{theory name} which prints the given name,
  3029 after checking that it refers to a valid ancestor theory in the
  3030 current context.
  3031 
  3032 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3033 check the given source text as ML type/structure, printing verbatim.
  3034 
  3035 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3036 "c args == rhs" given in the current context.  (Any number of
  3037 arguments may be given on the LHS.)
  3038 
  3039 
  3040 *** Pure ***
  3041 
  3042 * The 'class' package offers a combination of axclass and locale to
  3043 achieve Haskell-like type classes in Isabelle.  Definitions and
  3044 theorems within a class context produce both relative results (with
  3045 implicit parameters according to the locale context), and polymorphic
  3046 constants with qualified polymorphism (according to the class
  3047 context).  Within the body context of a 'class' target, a separate
  3048 syntax layer ("user space type system") takes care of converting
  3049 between global polymorphic consts and internal locale representation.
  3050 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3051 "isatool doc classes" provides a tutorial.
  3052 
  3053 * Generic code generator framework allows to generate executable
  3054 code for ML and Haskell (including Isabelle classes).  A short usage
  3055 sketch:
  3056 
  3057     internal compilation:
  3058         export_code <list of constants (term syntax)> in SML
  3059     writing SML code to a file:
  3060         export_code <list of constants (term syntax)> in SML <filename>
  3061     writing OCaml code to a file:
  3062         export_code <list of constants (term syntax)> in OCaml <filename>
  3063     writing Haskell code to a bunch of files:
  3064         export_code <list of constants (term syntax)> in Haskell <filename>
  3065 
  3066     evaluating closed propositions to True/False using code generation:
  3067         method ``eval''
  3068 
  3069 Reasonable default setup of framework in HOL.
  3070 
  3071 Theorem attributs for selecting and transforming function equations theorems:
  3072 
  3073     [code fun]:        select a theorem as function equation for a specific constant
  3074     [code fun del]:    deselect a theorem as function equation for a specific constant
  3075     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3076     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3077 
  3078 User-defined serializations (target in {SML, OCaml, Haskell}):
  3079 
  3080     code_const <and-list of constants (term syntax)>
  3081       {(target) <and-list of const target syntax>}+
  3082 
  3083     code_type <and-list of type constructors>
  3084       {(target) <and-list of type target syntax>}+
  3085 
  3086     code_instance <and-list of instances>
  3087       {(target)}+
  3088         where instance ::= <type constructor> :: <class>
  3089 
  3090     code_class <and_list of classes>
  3091       {(target) <and-list of class target syntax>}+
  3092         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3093 
  3094 code_instance and code_class only are effective to target Haskell.
  3095 
  3096 For example usage see src/HOL/ex/Codegenerator.thy and
  3097 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3098 generation from Isabelle/HOL theories is available via "isatool doc
  3099 codegen".
  3100 
  3101 * Code generator: consts in 'consts_code' Isar commands are now
  3102 referred to by usual term syntax (including optional type
  3103 annotations).
  3104 
  3105 * Command 'no_translations' removes translation rules from theory
  3106 syntax.
  3107 
  3108 * Overloaded definitions are now actually checked for acyclic
  3109 dependencies.  The overloading scheme is slightly more general than
  3110 that of Haskell98, although Isabelle does not demand an exact
  3111 correspondence to type class and instance declarations.
  3112 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3113 exotic versions of overloading -- at the discretion of the user!
  3114 
  3115 Polymorphic constants are represented via type arguments, i.e. the
  3116 instantiation that matches an instance against the most general
  3117 declaration given in the signature.  For example, with the declaration
  3118 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3119 as c(nat).  Overloading is essentially simultaneous structural
  3120 recursion over such type arguments.  Incomplete specification patterns
  3121 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3122 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3123 Command 'print_theory' outputs the normalized system of recursive
  3124 equations, see section "definitions".
  3125 
  3126 * Configuration options are maintained within the theory or proof
  3127 context (with name and type bool/int/string), providing a very simple
  3128 interface to a poor-man's version of general context data.  Tools may
  3129 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3130 these values using Config.get etc.  Users may change options via an
  3131 associated attribute of the same name.  This form of context
  3132 declaration works particularly well with commands 'declare' or
  3133 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3134 very easy to avoid global references, which would not observe Isar
  3135 toplevel undo/redo and fail to work with multithreading.
  3136 
  3137 Various global ML references of Pure and HOL have been turned into
  3138 configuration options:
  3139 
  3140   Unify.search_bound		unify_search_bound
  3141   Unify.trace_bound		unify_trace_bound
  3142   Unify.trace_simp		unify_trace_simp
  3143   Unify.trace_types		unify_trace_types
  3144   Simplifier.simp_depth_limit	simp_depth_limit
  3145   Blast.depth_limit		blast_depth_limit
  3146   DatatypeProp.dtK		datatype_distinctness_limit
  3147   fast_arith_neq_limit  	fast_arith_neq_limit
  3148   fast_arith_split_limit	fast_arith_split_limit
  3149 
  3150 * Named collections of theorems may be easily installed as context
  3151 data using the functor NamedThmsFun (see also
  3152 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3153 attributes; there is also a toplevel print command.  This facility is
  3154 just a common case of general context data, which is the preferred way
  3155 for anything more complex than just a list of facts in canonical
  3156 order.
  3157 
  3158 * Isar: command 'declaration' augments a local theory by generic
  3159 declaration functions written in ML.  This enables arbitrary content
  3160 being added to the context, depending on a morphism that tells the
  3161 difference of the original declaration context wrt. the application
  3162 context encountered later on.
  3163 
  3164 * Isar: proper interfaces for simplification procedures.  Command
  3165 'simproc_setup' declares named simprocs (with match patterns, and body
  3166 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3167 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3168 
  3169 * Isar: an extra pair of brackets around attribute declarations
  3170 abbreviates a theorem reference involving an internal dummy fact,
  3171 which will be ignored later --- only the effect of the attribute on
  3172 the background context will persist.  This form of in-place
  3173 declarations is particularly useful with commands like 'declare' and
  3174 'using', for example ``have A using [[simproc a]] by simp''.
  3175 
  3176 * Isar: method "assumption" (and implicit closing of subproofs) now
  3177 takes simple non-atomic goal assumptions into account: after applying
  3178 an assumption as a rule the resulting subgoals are solved by atomic
  3179 assumption steps.  This is particularly useful to finish 'obtain'
  3180 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3181 without referring to the original premise "!!x. P x ==> thesis" in the
  3182 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3183 more permissive.
  3184 
  3185 * Isar: implicit use of prems from the Isar proof context is
  3186 considered a legacy feature.  Common applications like ``have A .''
  3187 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3188 referencing facts explicitly here improves readability and
  3189 maintainability of proof texts.
  3190 
  3191 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3192 the obtained context from the course of reasoning!  For example:
  3193 
  3194   assume "EX x y. A x & B y"   -- "any previous fact"
  3195   then guess x and y by clarify
  3196 
  3197 This technique is potentially adventurous, depending on the facts and
  3198 proof tools being involved here.
  3199 
  3200 * Isar: known facts from the proof context may be specified as literal
  3201 propositions, using ASCII back-quote syntax.  This works wherever
  3202 named facts used to be allowed so far, in proof commands, proof
  3203 methods, attributes etc.  Literal facts are retrieved from the context
  3204 according to unification of type and term parameters.  For example,
  3205 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3206 theorems in the current context, then these are valid literal facts:
  3207 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3208 
  3209 There is also a proof method "fact" which does the same composition
  3210 for explicit goal states, e.g. the following proof texts coincide with
  3211 certain special cases of literal facts:
  3212 
  3213   have "A" by fact                 ==  note `A`
  3214   have "A ==> B" by fact           ==  note `A ==> B`
  3215   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3216   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3217 
  3218 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3219 outer syntax.  Thus symbolic identifiers may be used without
  3220 additional white space in declarations like this: ``assume *: A''.
  3221 
  3222 * Isar: 'print_facts' prints all local facts of the current context,
  3223 both named and unnamed ones.
  3224 
  3225 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3226 
  3227   def x == "t" and y == "u"
  3228 
  3229 * Isar: added command 'unfolding', which is structurally similar to
  3230 'using', but affects both the goal state and facts by unfolding given
  3231 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3232 'unfolded' attribute may be replaced by first-class proof text.
  3233 
  3234 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3235 and command 'unfolding' now all support object-level equalities
  3236 (potentially conditional).  The underlying notion of rewrite rule is
  3237 analogous to the 'rule_format' attribute, but *not* that of the
  3238 Simplifier (which is usually more generous).
  3239 
  3240 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3241 premises of a theorem by n. Useful in conjunction with drule.
  3242 
  3243 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3244 method expression within a sandbox consisting of the first N
  3245 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3246 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3247 simplifies all new goals that emerge from applying rule foo to the
  3248 originally first one.
  3249 
  3250 * Isar: schematic goals are no longer restricted to higher-order
  3251 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3252 expected.
  3253 
  3254 * Isar: the conclusion of a long theorem statement is now either
  3255 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3256 (essentially a disjunction of cases with local parameters and
  3257 assumptions).  The latter allows to express general elimination rules
  3258 adequately; in this notation common elimination rules look like this:
  3259 
  3260   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3261     assumes "EX x. P x"
  3262     obtains x where "P x"
  3263 
  3264   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3265     assumes "A & B"
  3266     obtains A and B
  3267 
  3268   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3269     assumes "A | B"
  3270     obtains
  3271       A
  3272     | B
  3273 
  3274 The subsequent classical rules even refer to the formal "thesis"
  3275 explicitly:
  3276 
  3277   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3278     obtains "~ thesis"
  3279 
  3280   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3281     obtains "thesis ==> something"
  3282 
  3283 The actual proof of an 'obtains' statement is analogous to that of the
  3284 Isar proof element 'obtain', only that there may be several cases.
  3285 Optional case names may be specified in parentheses; these will be
  3286 available both in the present proof and as annotations in the
  3287 resulting rule, for later use with the 'cases' method (cf. attribute
  3288 case_names).
  3289 
  3290 * Isar: the assumptions of a long theorem statement are available as
  3291 "assms" fact in the proof context.  This is more appropriate than the
  3292 (historical) "prems", which refers to all assumptions of the current
  3293 context, including those from the target locale, proof body etc.
  3294 
  3295 * Isar: 'print_statement' prints theorems from the current theory or
  3296 proof context in long statement form, according to the syntax of a
  3297 top-level lemma.
  3298 
  3299 * Isar: 'obtain' takes an optional case name for the local context
  3300 introduction rule (default "that").
  3301 
  3302 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3303 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3304 to occur.
  3305 
  3306 * Pure: syntax "CONST name" produces a fully internalized constant
  3307 according to the current context.  This is particularly useful for
  3308 syntax translations that should refer to internal constant
  3309 representations independently of name spaces.
  3310 
  3311 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3312 instead of "FOO ". This allows multiple binder declarations to coexist
  3313 in the same context.  INCOMPATIBILITY.
  3314 
  3315 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3316 primitive that also works in a locale context (both for constants and
  3317 fixed variables). Type declaration and internal syntactic representation
  3318 of given constants retrieved from the context. Likewise, the
  3319 'no_notation' command allows to remove given syntax annotations from the
  3320 current context.
  3321 
  3322 * Isar/locales: new derived specification elements 'axiomatization',
  3323 'definition', 'abbreviation', which support type-inference, admit
  3324 object-level specifications (equality, equivalence).  See also the
  3325 isar-ref manual.  Examples:
  3326 
  3327   axiomatization
  3328     eq  (infix "===" 50) where
  3329     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3330 
  3331   definition "f x y = x + y + 1"
  3332   definition g where "g x = f x x"
  3333 
  3334   abbreviation
  3335     neq  (infix "=!=" 50) where
  3336     "x =!= y == ~ (x === y)"
  3337 
  3338 These specifications may be also used in a locale context.  Then the
  3339 constants being introduced depend on certain fixed parameters, and the
  3340 constant name is qualified by the locale base name.  An internal
  3341 abbreviation takes care for convenient input and output, making the
  3342 parameters implicit and using the original short name.  See also
  3343 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3344 entities from a monomorphic theory.
  3345 
  3346 Presently, abbreviations are only available 'in' a target locale, but
  3347 not inherited by general import expressions.  Also note that
  3348 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3349 'translations' in common applications.  The "no_abbrevs" print mode
  3350 prevents folding of abbreviations in term output.
  3351 
  3352 Concrete syntax is attached to specified constants in internal form,
  3353 independently of name spaces.  The parse tree representation is
  3354 slightly different -- use 'notation' instead of raw 'syntax', and
  3355 'translations' with explicit "CONST" markup to accommodate this.
  3356 
  3357 * Pure/Isar: unified syntax for new-style specification mechanisms
  3358 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3359 full type inference and dummy patterns ("_").  For example:
  3360 
  3361   definition "K x _ = x"
  3362 
  3363   inductive conj for A B
  3364   where "A ==> B ==> conj A B"
  3365 
  3366 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3367 the current context.  Print mode "no_abbrevs" prevents inversion of
  3368 abbreviations on output.
  3369 
  3370 * Isar/locales: improved parameter handling: use of locales "var" and
  3371 "struct" no longer necessary; - parameter renamings are no longer
  3372 required to be injective.  For example, this allows to define
  3373 endomorphisms as locale endom = homom mult mult h.
  3374 
  3375 * Isar/locales: changed the way locales with predicates are defined.
  3376 Instead of accumulating the specification, the imported expression is
  3377 now an interpretation.  INCOMPATIBILITY: different normal form of
  3378 locale expressions.  In particular, in interpretations of locales with
  3379 predicates, goals repesenting already interpreted fragments are not
  3380 removed automatically.  Use methods `intro_locales' and
  3381 `unfold_locales'; see below.
  3382 
  3383 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3384 provide backward reasoning on locales predicates.  The methods are
  3385 aware of interpretations and discharge corresponding goals.
  3386 `intro_locales' is less aggressive then `unfold_locales' and does not
  3387 unfold predicates to assumptions.
  3388 
  3389 * Isar/locales: the order in which locale fragments are accumulated
  3390 has changed.  This enables to override declarations from fragments due
  3391 to interpretations -- for example, unwanted simp rules.
  3392 
  3393 * Isar/locales: interpretation in theories and proof contexts has been
  3394 extended.  One may now specify (and prove) equations, which are
  3395 unfolded in interpreted theorems.  This is useful for replacing
  3396 defined concepts (constants depending on locale parameters) by
  3397 concepts already existing in the target context.  Example:
  3398 
  3399   interpretation partial_order ["op <= :: [int, int] => bool"]
  3400     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3401 
  3402 Typically, the constant `partial_order.less' is created by a
  3403 definition specification element in the context of locale
  3404 partial_order.
  3405 
  3406 * Method "induct": improved internal context management to support
  3407 local fixes and defines on-the-fly. Thus explicit meta-level
  3408 connectives !!  and ==> are rarely required anymore in inductive goals
  3409 (using object-logic connectives for this purpose has been long
  3410 obsolete anyway). Common proof patterns are explained in
  3411 src/HOL/Induct/Common_Patterns.thy, see also
  3412 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3413 examples.
  3414 
  3415 * Method "induct": improved handling of simultaneous goals. Instead of
  3416 introducing object-level conjunction, the statement is now split into
  3417 several conclusions, while the corresponding symbolic cases are nested
  3418 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3419 see src/HOL/Induct/Common_Patterns.thy, for example.
  3420 
  3421 * Method "induct": mutual induction rules are now specified as a list
  3422 of rule sharing the same induction cases. HOL packages usually provide
  3423 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3424 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3425 mutual induction rules differently, i.e. like this:
  3426 
  3427   (induct rule: foo_bar.inducts)
  3428   (induct set: foo bar)
  3429   (induct pred: foo bar)
  3430   (induct type: foo bar)
  3431 
  3432 The ML function ProjectRule.projections turns old-style rules into the
  3433 new format.
  3434 
  3435 * Method "coinduct": dual of induction, see
  3436 src/HOL/Library/Coinductive_List.thy for various examples.
  3437 
  3438 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3439 considered a legacy feature.
  3440 
  3441 * Attribute "symmetric" produces result with standardized schematic
  3442 variables (index 0).  Potential INCOMPATIBILITY.
  3443 
  3444 * Simplifier: by default the simplifier trace only shows top level
  3445 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3446 default. Thus there is less danger of being flooded by the trace. The
  3447 trace indicates where parts have been suppressed.
  3448   
  3449 * Provers/classical: removed obsolete classical version of elim_format
  3450 attribute; classical elim/dest rules are now treated uniformly when
  3451 manipulating the claset.
  3452 
  3453 * Provers/classical: stricter checks to ensure that supplied intro,
  3454 dest and elim rules are well-formed; dest and elim rules must have at
  3455 least one premise.
  3456 
  3457 * Provers/classical: attributes dest/elim/intro take an optional
  3458 weight argument for the rule (just as the Pure versions).  Weights are
  3459 ignored by automated tools, but determine the search order of single
  3460 rule steps.
  3461 
  3462 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3463 where the body does not mention the bound variable.  Note that dummy
  3464 patterns implicitly depend on their context of bounds, which makes
  3465 "{_. _}" match any set comprehension as expected.  Potential
  3466 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3467 constant "_idtdummy" in the binding position.
  3468 
  3469 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3470 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3471 for example "A -> B" => "Pi A (%_. B)".
  3472 
  3473 * Pure: 'class_deps' command visualizes the subclass relation, using
  3474 the graph browser tool.
  3475 
  3476 * Pure: 'print_theory' now suppresses certain internal declarations by
  3477 default; use '!' option for full details.
  3478 
  3479 
  3480 *** HOL ***
  3481 
  3482 * Method "metis" proves goals by applying the Metis general-purpose
  3483 resolution prover (see also http://gilith.com/software/metis/).
  3484 Examples are in the directory MetisExamples.  WARNING: the
  3485 Isabelle/HOL-Metis integration does not yet work properly with
  3486 multi-threading.
  3487   
  3488 * Command 'sledgehammer' invokes external automatic theorem provers as
  3489 background processes.  It generates calls to the "metis" method if
  3490 successful. These can be pasted into the proof.  Users do not have to
  3491 wait for the automatic provers to return.  WARNING: does not really
  3492 work with multi-threading.
  3493 
  3494 * New "auto_quickcheck" feature tests outermost goal statements for
  3495 potential counter-examples.  Controlled by ML references
  3496 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3497 5000 milliseconds).  Fails silently if statements is outside of
  3498 executable fragment, or any other codgenerator problem occurs.
  3499 
  3500 * New constant "undefined" with axiom "undefined x = undefined".
  3501 
  3502 * Added class "HOL.eq", allowing for code generation with polymorphic
  3503 equality.
  3504 
  3505 * Some renaming of class constants due to canonical name prefixing in
  3506 the new 'class' package:
  3507 
  3508     HOL.abs ~> HOL.abs_class.abs
  3509     HOL.divide ~> HOL.divide_class.divide
  3510     0 ~> HOL.zero_class.zero
  3511     1 ~> HOL.one_class.one
  3512     op + ~> HOL.plus_class.plus
  3513     op - ~> HOL.minus_class.minus
  3514     uminus ~> HOL.minus_class.uminus
  3515     op * ~> HOL.times_class.times
  3516     op < ~> HOL.ord_class.less
  3517     op <= > HOL.ord_class.less_eq
  3518     Nat.power ~> Power.power_class.power
  3519     Nat.size ~> Nat.size_class.size
  3520     Numeral.number_of ~> Numeral.number_class.number_of
  3521     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3522     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3523     Orderings.min ~> Orderings.ord_class.min
  3524     Orderings.max ~> Orderings.ord_class.max
  3525     Divides.op div ~> Divides.div_class.div
  3526     Divides.op mod ~> Divides.div_class.mod
  3527     Divides.op dvd ~> Divides.div_class.dvd
  3528 
  3529 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3530 
  3531 a) User-defined constants using any of the names "plus", "minus",
  3532 "times", "less" or "less_eq". The standard syntax translations for
  3533 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3534 names.
  3535 
  3536 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3537 INCOMPATIBILITY: use more specific names.
  3538 
  3539 c) Permutative equations (e.g. "a + b = b + a")
  3540 Since the change of names also changes the order of terms, permutative
  3541 rewrite rules may get applied in a different order. Experience shows
  3542 that this is rarely the case (only two adaptions in the whole Isabelle
  3543 distribution).  INCOMPATIBILITY: rewrite proofs
  3544 
  3545 d) ML code directly refering to constant names
  3546 This in general only affects hand-written proof tactics, simprocs and
  3547 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3548 Consider using @{const_name} antiquotation.
  3549 
  3550 * New class "default" with associated constant "default".
  3551 
  3552 * Function "sgn" is now overloaded and available on int, real, complex
  3553 (and other numeric types), using class "sgn".  Two possible defs of
  3554 sgn are given as equational assumptions in the classes sgn_if and
  3555 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3556 INCOMPATIBILITY.
  3557 
  3558 * Locale "partial_order" now unified with class "order" (cf. theory
  3559 Orderings), added parameter "less".  INCOMPATIBILITY.
  3560 
  3561 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3562 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3563 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3564 
  3565 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3566 changed order of proof goals in instance proofs.
  3567 
  3568 * The transitivity reasoner for partial and linear orders is set up
  3569 for classes "order" and "linorder".  Instances of the reasoner are available
  3570 in all contexts importing or interpreting the corresponding locales.
  3571 Method "order" invokes the reasoner separately; the reasoner
  3572 is also integrated with the Simplifier as a solver.  Diagnostic
  3573 command 'print_orders' shows the available instances of the reasoner
  3574 in the current context.
  3575 
  3576 * Localized monotonicity predicate in theory "Orderings"; integrated
  3577 lemmas max_of_mono and min_of_mono with this predicate.
  3578 INCOMPATIBILITY.
  3579 
  3580 * Formulation of theorem "dense" changed slightly due to integration
  3581 with new class dense_linear_order.
  3582 
  3583 * Uniform lattice theory development in HOL.
  3584 
  3585     constants "meet" and "join" now named "inf" and "sup"
  3586     constant "Meet" now named "Inf"
  3587 
  3588     classes "meet_semilorder" and "join_semilorder" now named
  3589       "lower_semilattice" and "upper_semilattice"
  3590     class "lorder" now named "lattice"
  3591     class "comp_lat" now named "complete_lattice"
  3592 
  3593     Instantiation of lattice classes allows explicit definitions
  3594     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3595 
  3596   INCOMPATIBILITY.  Theorem renames:
  3597 
  3598     meet_left_le            ~> inf_le1
  3599     meet_right_le           ~> inf_le2
  3600     join_left_le            ~> sup_ge1
  3601     join_right_le           ~> sup_ge2
  3602     meet_join_le            ~> inf_sup_ord
  3603     le_meetI                ~> le_infI
  3604     join_leI                ~> le_supI
  3605     le_meet                 ~> le_inf_iff
  3606     le_join                 ~> ge_sup_conv
  3607     meet_idempotent         ~> inf_idem
  3608     join_idempotent         ~> sup_idem
  3609     meet_comm               ~> inf_commute
  3610     join_comm               ~> sup_commute
  3611     meet_leI1               ~> le_infI1
  3612     meet_leI2               ~> le_infI2
  3613     le_joinI1               ~> le_supI1
  3614     le_joinI2               ~> le_supI2
  3615     meet_assoc              ~> inf_assoc
  3616     join_assoc              ~> sup_assoc
  3617     meet_left_comm          ~> inf_left_commute
  3618     meet_left_idempotent    ~> inf_left_idem
  3619     join_left_comm          ~> sup_left_commute
  3620     join_left_idempotent    ~> sup_left_idem
  3621     meet_aci                ~> inf_aci
  3622     join_aci                ~> sup_aci
  3623     le_def_meet             ~> le_iff_inf
  3624     le_def_join             ~> le_iff_sup
  3625     join_absorp2            ~> sup_absorb2
  3626     join_absorp1            ~> sup_absorb1
  3627     meet_absorp1            ~> inf_absorb1
  3628     meet_absorp2            ~> inf_absorb2
  3629     meet_join_absorp        ~> inf_sup_absorb
  3630     join_meet_absorp        ~> sup_inf_absorb
  3631     distrib_join_le         ~> distrib_sup_le
  3632     distrib_meet_le         ~> distrib_inf_le
  3633 
  3634     add_meet_distrib_left   ~> add_inf_distrib_left
  3635     add_join_distrib_left   ~> add_sup_distrib_left
  3636     is_join_neg_meet        ~> is_join_neg_inf
  3637     is_meet_neg_join        ~> is_meet_neg_sup
  3638     add_meet_distrib_right  ~> add_inf_distrib_right
  3639     add_join_distrib_right  ~> add_sup_distrib_right
  3640     add_meet_join_distribs  ~> add_sup_inf_distribs
  3641     join_eq_neg_meet        ~> sup_eq_neg_inf
  3642     meet_eq_neg_join        ~> inf_eq_neg_sup
  3643     add_eq_meet_join        ~> add_eq_inf_sup
  3644     meet_0_imp_0            ~> inf_0_imp_0
  3645     join_0_imp_0            ~> sup_0_imp_0
  3646     meet_0_eq_0             ~> inf_0_eq_0
  3647     join_0_eq_0             ~> sup_0_eq_0
  3648     neg_meet_eq_join        ~> neg_inf_eq_sup
  3649     neg_join_eq_meet        ~> neg_sup_eq_inf
  3650     join_eq_if              ~> sup_eq_if
  3651 
  3652     mono_meet               ~> mono_inf
  3653     mono_join               ~> mono_sup
  3654     meet_bool_eq            ~> inf_bool_eq
  3655     join_bool_eq            ~> sup_bool_eq
  3656     meet_fun_eq             ~> inf_fun_eq
  3657     join_fun_eq             ~> sup_fun_eq
  3658     meet_set_eq             ~> inf_set_eq
  3659     join_set_eq             ~> sup_set_eq
  3660     meet1_iff               ~> inf1_iff
  3661     meet2_iff               ~> inf2_iff
  3662     meet1I                  ~> inf1I
  3663     meet2I                  ~> inf2I
  3664     meet1D1                 ~> inf1D1
  3665     meet2D1                 ~> inf2D1
  3666     meet1D2                 ~> inf1D2
  3667     meet2D2                 ~> inf2D2
  3668     meet1E                  ~> inf1E
  3669     meet2E                  ~> inf2E
  3670     join1_iff               ~> sup1_iff
  3671     join2_iff               ~> sup2_iff
  3672     join1I1                 ~> sup1I1
  3673     join2I1                 ~> sup2I1
  3674     join1I1                 ~> sup1I1
  3675     join2I2                 ~> sup1I2
  3676     join1CI                 ~> sup1CI
  3677     join2CI                 ~> sup2CI
  3678     join1E                  ~> sup1E
  3679     join2E                  ~> sup2E
  3680 
  3681     is_meet_Meet            ~> is_meet_Inf
  3682     Meet_bool_def           ~> Inf_bool_def
  3683     Meet_fun_def            ~> Inf_fun_def
  3684     Meet_greatest           ~> Inf_greatest
  3685     Meet_lower              ~> Inf_lower
  3686     Meet_set_def            ~> Inf_set_def
  3687 
  3688     Sup_def                 ~> Sup_Inf
  3689     Sup_bool_eq             ~> Sup_bool_def
  3690     Sup_fun_eq              ~> Sup_fun_def
  3691     Sup_set_eq              ~> Sup_set_def
  3692 
  3693     listsp_meetI            ~> listsp_infI
  3694     listsp_meet_eq          ~> listsp_inf_eq
  3695 
  3696     meet_min                ~> inf_min
  3697     join_max                ~> sup_max
  3698 
  3699 * Added syntactic class "size"; overloaded constant "size" now has
  3700 type "'a::size ==> bool"
  3701 
  3702 * Internal reorganisation of `size' of datatypes: size theorems
  3703 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3704 simplification rules by default!); theorems "prod.size" now named
  3705 "*.size".
  3706 
  3707 * Class "div" now inherits from class "times" rather than "type".
  3708 INCOMPATIBILITY.
  3709 
  3710 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3711 Linorder etc.  have disappeared; operations defined in terms of
  3712 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3713 
  3714 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3715 
  3716 * HOL-Word: New extensive library and type for generic, fixed size
  3717 machine words, with arithemtic, bit-wise, shifting and rotating
  3718 operations, reflection into int, nat, and bool lists, automation for
  3719 linear arithmetic (by automatic reflection into nat or int), including
  3720 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3721 arithmetic type classes, supporting automatic simplification of
  3722 numerals on all operations.
  3723 
  3724 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3725 
  3726 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3727 
  3728 * Code generator library theories:
  3729   - Code_Integer represents HOL integers by big integer literals in target
  3730     languages.
  3731   - Code_Char represents HOL characters by character literals in target
  3732     languages.
  3733   - Code_Char_chr like Code_Char, but also offers treatment of character
  3734     codes; includes Code_Integer.
  3735   - Executable_Set allows to generate code for finite sets using lists.
  3736   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3737     denominator).
  3738   - Executable_Real implements a subset of real numbers, namly those
  3739     representable by rational numbers.
  3740   - Efficient_Nat implements natural numbers by integers, which in general will
  3741     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3742     includes Code_Integer.
  3743   - Code_Index provides an additional datatype index which is mapped to
  3744     target-language built-in integers.
  3745   - Code_Message provides an additional datatype message_string which is isomorphic to
  3746     strings; messages are mapped to target-language strings.
  3747 
  3748 * New package for inductive predicates
  3749 
  3750   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3751 
  3752     inductive
  3753       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3754       for z_1 :: U_1 and ... and z_n :: U_m
  3755     where
  3756       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3757     | ...
  3758 
  3759   with full support for type-inference, rather than
  3760 
  3761     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3762 
  3763     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3764     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3765 
  3766     inductive "s z_1 ... z_m"
  3767     intros
  3768       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3769       ...
  3770 
  3771   For backward compatibility, there is a wrapper allowing inductive
  3772   sets to be defined with the new package via
  3773 
  3774     inductive_set
  3775       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3776       for z_1 :: U_1 and ... and z_n :: U_m
  3777     where
  3778       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3779     | ...
  3780 
  3781   or
  3782 
  3783     inductive_set
  3784       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3785       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3786       for z_1 :: U_1 and ... and z_n :: U_m
  3787     where
  3788       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3789     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3790     | ...
  3791 
  3792   if the additional syntax "p ..." is required.
  3793 
  3794   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3795   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3796 
  3797   INCOMPATIBILITIES:
  3798 
  3799   - Since declaration and definition of inductive sets or predicates
  3800     is no longer separated, abbreviations involving the newly
  3801     introduced sets or predicates must be specified together with the
  3802     introduction rules after the 'where' keyword (see above), rather
  3803     than before the actual inductive definition.
  3804 
  3805   - The variables in induction and elimination rules are now
  3806     quantified in the order of their occurrence in the introduction
  3807     rules, rather than in alphabetical order. Since this may break
  3808     some proofs, these proofs either have to be repaired, e.g. by
  3809     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3810     statements of the form
  3811 
  3812       case (rule_i a_i_1 ... a_i_{k_i})
  3813 
  3814     or the old order of quantification has to be restored by explicitly adding
  3815     meta-level quantifiers in the introduction rules, i.e.
  3816 
  3817       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3818 
  3819   - The format of the elimination rules is now
  3820 
  3821       p z_1 ... z_m x_1 ... x_n ==>
  3822         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3823         ==> ... ==> P
  3824 
  3825     for predicates and
  3826 
  3827       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3828         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3829         ==> ... ==> P
  3830 
  3831     for sets rather than
  3832 
  3833       x : s z_1 ... z_m ==>
  3834         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3835         ==> ... ==> P
  3836 
  3837     This may require terms in goals to be expanded to n-tuples
  3838     (e.g. using case_tac or simplification with the split_paired_all
  3839     rule) before the above elimination rule is applicable.
  3840 
  3841   - The elimination or case analysis rules for (mutually) inductive
  3842     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3843     list of rules "p_1_..._p_k.elims" is no longer available.
  3844 
  3845 * New package "function"/"fun" for general recursive functions,
  3846 supporting mutual and nested recursion, definitions in local contexts,
  3847 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3848 for small examples, and the separate tutorial on the function
  3849 package. The old recdef "package" is still available as before, but
  3850 users are encouraged to use the new package.
  3851 
  3852 * Method "lexicographic_order" automatically synthesizes termination
  3853 relations as lexicographic combinations of size measures. 
  3854 
  3855 * Case-expressions allow arbitrary constructor-patterns (including
  3856 "_") and take their order into account, like in functional
  3857 programming.  Internally, this is translated into nested
  3858 case-expressions; missing cases are added and mapped to the predefined
  3859 constant "undefined". In complicated cases printing may no longer show
  3860 the original input but the internal form. Lambda-abstractions allow
  3861 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3862 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3863 variable.
  3864 
  3865 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3866 is an abbreviation for "of_nat :: nat => int". The simplification
  3867 rules for "of_nat" have been changed to work like "int" did
  3868 previously.  Potential INCOMPATIBILITY:
  3869   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3870   - of_nat_diff and of_nat_mult are no longer default simp rules
  3871 
  3872 * Method "algebra" solves polynomial equations over (semi)rings using
  3873 Groebner bases. The (semi)ring structure is defined by locales and the
  3874 tool setup depends on that generic context. Installing the method for
  3875 a specific type involves instantiating the locale and possibly adding
  3876 declarations for computation on the coefficients.  The method is
  3877 already instantiated for natural numbers and for the axiomatic class
  3878 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3879 CALCULEMUS 2007 for the general principles underlying this
  3880 architecture of context-aware proof-tools.
  3881 
  3882 * Method "ferrack" implements quantifier elimination over
  3883 special-purpose dense linear orders using locales (analogous to
  3884 "algebra"). The method is already installed for class
  3885 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3886 rat, etc.
  3887 
  3888 * Former constant "List.op @" now named "List.append".  Use ML
  3889 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3890 circumvent possible incompatibilities when working on ML level.
  3891 
  3892 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3893 
  3894 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3895 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3896 
  3897 * New syntax for Haskell-like list comprehension (input only), eg.
  3898 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3899 
  3900 * The special syntax for function "filter" has changed from [x :
  3901 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3902 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3903 
  3904 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3905 defined on nat only, as an abbreviation for [a..<Suc b]
  3906 INCOMPATIBILITY.
  3907 
  3908 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3909 
  3910 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3911 
  3912 * New lemma collection field_simps (an extension of ring_simps) for
  3913 manipulating (in)equations involving division. Multiplies with all
  3914 denominators that can be proved to be non-zero (in equations) or
  3915 positive/negative (in inequations).
  3916 
  3917 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3918 have been improved and renamed to ring_simps, group_simps and
  3919 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3920 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3921 
  3922 * Theory Library/Commutative_Ring: switched from recdef to function
  3923 package; constants add, mul, pow now curried.  Infix syntax for
  3924 algebraic operations.
  3925 
  3926 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3927 INCOMPATIBILITY.
  3928 
  3929 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3930 INCOMPATIBILITY.
  3931 
  3932 * HOL/records: generalised field-update to take a function on the
  3933 field rather than the new value: r(|A := x|) is translated to A_update
  3934 (K x) r The K-combinator that is internally used is called K_record.
  3935 INCOMPATIBILITY: Usage of the plain update functions has to be
  3936 adapted.
  3937  
  3938 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3939 * x = 0, which are required for a semiring.  Richer structures do not
  3940 inherit from semiring_0 anymore, because this property is a theorem
  3941 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3942 there is more to prove, but this is mostly trivial.
  3943 
  3944 * Class "recpower" is generalized to arbitrary monoids, not just
  3945 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3946 commutativity or semiring properties additionally.
  3947 
  3948 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3949 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3950 better use 'abbreviation'.
  3951 
  3952 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3953 
  3954 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3955 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3956 significant changes for setting up numeral syntax for types:
  3957   - New constants Numeral.pred and Numeral.succ instead
  3958       of former Numeral.bin_pred and Numeral.bin_succ.
  3959   - Use integer operations instead of bin_add, bin_mult and so on.
  3960   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3961   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3962 
  3963 See src/HOL/Integ/IntArith.thy for an example setup.
  3964 
  3965 * Command 'normal_form' computes the normal form of a term that may
  3966 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3967 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3968 heavy-duty computations because the functions are compiled to ML
  3969 first.  Correspondingly, a method "normalization" is provided.  See
  3970 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3971 
  3972 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3973 25 like -->); output depends on the "iff" print_mode, the default is
  3974 "A = B" (with priority 50).
  3975 
  3976 * Relations less (<) and less_eq (<=) are also available on type bool.
  3977 Modified syntax to disallow nesting without explicit parentheses,
  3978 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3979 INCOMPATIBILITY.
  3980 
  3981 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3982 
  3983 * Relation composition operator "op O" now has precedence 75 and binds
  3984 stronger than union and intersection. INCOMPATIBILITY.
  3985 
  3986 * The old set interval syntax "{m..n(}" (and relatives) has been
  3987 removed.  Use "{m..<n}" (and relatives) instead.
  3988 
  3989 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3990 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3991 ``declare [[simproc del: neq]]''.
  3992 
  3993 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3994 True/False.
  3995 
  3996 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3997 
  3998 * Theorem setsum_mult renamed to setsum_right_distrib.
  3999 
  4000 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4001 ``rule'' method.
  4002 
  4003 * Reimplemented methods "sat" and "satx", with several improvements:
  4004 goals no longer need to be stated as "<prems> ==> False", equivalences
  4005 (i.e. "=" on type bool) are handled, variable names of the form
  4006 "lit_<n>" are no longer reserved, significant speedup.
  4007 
  4008 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4009 zChaff is still supported as well.
  4010 
  4011 * 'inductive' and 'datatype': provide projections of mutual rules,
  4012 bundled as foo_bar.inducts;
  4013 
  4014 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4015 Library.
  4016 
  4017 * Library: moved theory Accessible_Part to main HOL.
  4018 
  4019 * Library: added theory Coinductive_List of potentially infinite lists
  4020 as greatest fixed-point.
  4021 
  4022 * Library: added theory AssocList which implements (finite) maps as
  4023 association lists.
  4024 
  4025 * Method "evaluation" solves goals (i.e. a boolean expression)
  4026 efficiently by compiling it to ML.  The goal is "proved" (via an
  4027 oracle) if it evaluates to True.
  4028 
  4029 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4030 also when invoked by the simplifier.  This results in the Simplifier
  4031 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4032 Configuration option fast_arith_split_limit=0 recovers the old
  4033 behavior.
  4034 
  4035 * Support for hex (0x20) and binary (0b1001) numerals.
  4036 
  4037 * New method: reify eqs (t), where eqs are equations for an
  4038 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4039 parameter, computes a term s::'b and a list xs::'a list and proves the
  4040 theorem I xs s = t. This is also known as reification or quoting. The
  4041 resulting theorem is applied to the subgoal to substitute t with I xs
  4042 s.  If t is omitted, the subgoal itself is reified.
  4043 
  4044 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4045 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4046 where f is supposed to be a computable function (in the sense of code
  4047 generattion). The method uses reify to compute s and xs as above then
  4048 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4049 r and finally gets the theorem t = r, which is again applied to the
  4050 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4051 
  4052 * Reflection: Automatic reification now handels binding, an example is
  4053 available in src/HOL/ex/ReflectionEx.thy
  4054 
  4055 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4056 command 'statespace' that is similar to 'record', but introduces an
  4057 abstract specification based on the locale infrastructure instead of
  4058 HOL types.  This leads to extra flexibility in composing state spaces,
  4059 in particular multiple inheritance and renaming of components.
  4060 
  4061 
  4062 *** HOL-Complex ***
  4063 
  4064 * Hyperreal: Functions root and sqrt are now defined on negative real
  4065 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4066 Nonnegativity side conditions have been removed from many lemmas, so
  4067 that more subgoals may now be solved by simplification; potential
  4068 INCOMPATIBILITY.
  4069 
  4070 * Real: new type classes formalize real normed vector spaces and
  4071 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4072 and norm :: 'a => real.
  4073 
  4074 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4075 reals into other types. The overloaded constant Reals :: 'a set is now
  4076 defined as range of_real; potential INCOMPATIBILITY.
  4077 
  4078 * Real: proper support for ML code generation, including 'quickcheck'.
  4079 Reals are implemented as arbitrary precision rationals.
  4080 
  4081 * Hyperreal: Several constants that previously worked only for the
  4082 reals have been generalized, so they now work over arbitrary vector
  4083 spaces. Type annotations may need to be added in some cases; potential
  4084 INCOMPATIBILITY.
  4085 
  4086   Infinitesimal  :: ('a::real_normed_vector) star set
  4087   HFinite        :: ('a::real_normed_vector) star set
  4088   HInfinite      :: ('a::real_normed_vector) star set
  4089   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4090   monad          :: ('a::real_normed_vector) star => 'a star set
  4091   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4092   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4093   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4094   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4095   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4096   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4097   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4098   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4099   sgn            :: 'a::real_normed_vector => 'a
  4100   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4101 
  4102 * Complex: Some complex-specific constants are now abbreviations for
  4103 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4104 hnorm.  Other constants have been entirely removed in favor of the
  4105 polymorphic versions (INCOMPATIBILITY):
  4106 
  4107   approx        <-- capprox
  4108   HFinite       <-- CFinite
  4109   HInfinite     <-- CInfinite
  4110   Infinitesimal <-- CInfinitesimal
  4111   monad         <-- cmonad
  4112   galaxy        <-- cgalaxy
  4113   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4114   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4115   (ns)deriv     <-- (ns)cderiv
  4116 
  4117 
  4118 *** HOL-Algebra ***
  4119 
  4120 * Formalisation of ideals and the quotient construction over rings.
  4121 
  4122 * Order and lattice theory no longer based on records.
  4123 INCOMPATIBILITY.
  4124 
  4125 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4126 greatest_closed.  INCOMPATIBILITY.
  4127 
  4128 * Method algebra is now set up via an attribute.  For examples see
  4129 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4130 of algebraic structures.
  4131 
  4132 * Renamed theory CRing to Ring.
  4133 
  4134 
  4135 *** HOL-Nominal ***
  4136 
  4137 * Substantial, yet incomplete support for nominal datatypes (binding
  4138 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4139 src/HOL/Nominal/Examples.  Prospective users should consult
  4140 http://isabelle.in.tum.de/nominal/
  4141 
  4142 
  4143 *** ML ***
  4144 
  4145 * ML basics: just one true type int, which coincides with IntInf.int
  4146 (even on SML/NJ).
  4147 
  4148 * ML within Isar: antiquotations allow to embed statically-checked
  4149 formal entities in the source, referring to the context available at
  4150 compile-time.  For example:
  4151 
  4152 ML {* @{sort "{zero,one}"} *}
  4153 ML {* @{typ "'a => 'b"} *}
  4154 ML {* @{term "%x. x"} *}
  4155 ML {* @{prop "x == y"} *}
  4156 ML {* @{ctyp "'a => 'b"} *}
  4157 ML {* @{cterm "%x. x"} *}
  4158 ML {* @{cprop "x == y"} *}
  4159 ML {* @{thm asm_rl} *}
  4160 ML {* @{thms asm_rl} *}
  4161 ML {* @{type_name c} *}
  4162 ML {* @{type_syntax c} *}
  4163 ML {* @{const_name c} *}
  4164 ML {* @{const_syntax c} *}
  4165 ML {* @{context} *}
  4166 ML {* @{theory} *}
  4167 ML {* @{theory Pure} *}
  4168 ML {* @{theory_ref} *}
  4169 ML {* @{theory_ref Pure} *}
  4170 ML {* @{simpset} *}
  4171 ML {* @{claset} *}
  4172 ML {* @{clasimpset} *}
  4173 
  4174 The same works for sources being ``used'' within an Isar context.
  4175 
  4176 * ML in Isar: improved error reporting; extra verbosity with
  4177 ML_Context.trace enabled.
  4178 
  4179 * Pure/General/table.ML: the join operations now works via exceptions
  4180 DUP/SAME instead of type option. This is simpler in simple cases, and
  4181 admits slightly more efficient complex applications.
  4182 
  4183 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4184 use Context.generic instead of just theory.
  4185 
  4186 * Pure: datatype Context.generic joins theory/Proof.context and
  4187 provides some facilities for code that works in either kind of
  4188 context, notably GenericDataFun for uniform theory and proof data.
  4189 
  4190 * Pure: simplified internal attribute type, which is now always
  4191 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4192 local (Proof.context) attributes have been discontinued, while
  4193 minimizing code duplication. Thm.rule_attribute and
  4194 Thm.declaration_attribute build canonical attributes; see also structure
  4195 Context for further operations on Context.generic, notably
  4196 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4197 declarations and definitions.
  4198 
  4199 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4200 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4201 init only required for impure data. INCOMPATIBILITY: empty really need
  4202 to be empty (no dependencies on theory content!)
  4203 
  4204 * Pure/kernel: consts certification ignores sort constraints given in
  4205 signature declarations. (This information is not relevant to the
  4206 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4207 potential INCOMPATIBILITY.
  4208 
  4209 * Pure: axiomatic type classes are now purely definitional, with
  4210 explicit proofs of class axioms and super class relations performed
  4211 internally. See Pure/axclass.ML for the main internal interfaces --
  4212 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4213 AxClass.axiomatize_class/classrel/arity supersede
  4214 Sign.add_classes/classrel/arities.
  4215 
  4216 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4217 global/local versions on theory vs. Proof.context have been
  4218 discontinued; Attrib.syntax and Method.syntax have been adapted
  4219 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4220 attributes, methods, etc.
  4221 
  4222 * Pure: several functions of signature "... -> theory -> theory * ..."
  4223 have been reoriented to "... -> theory -> ... * theory" in order to
  4224 allow natural usage in combination with the ||>, ||>>, |-> and
  4225 fold_map combinators.
  4226 
  4227 * Pure: official theorem names (closed derivations) and additional
  4228 comments (tags) are now strictly separate.  Name hints -- which are
  4229 maintained as tags -- may be attached any time without affecting the
  4230 derivation.
  4231 
  4232 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4233 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4234 achieve the old behaviour.
  4235 
  4236 * Pure: the "Goal" constant is now called "prop", supporting a
  4237 slightly more general idea of ``protecting'' meta-level rule
  4238 statements.
  4239 
  4240 * Pure: Logic.(un)varify only works in a global context, which is now
  4241 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4242 Logic.legacy_(un)varify as temporary workaround.
  4243 
  4244 * Pure: structure Name provides scalable operations for generating
  4245 internal variable names, notably Name.variants etc.  This replaces
  4246 some popular functions from term.ML:
  4247 
  4248   Term.variant		->  Name.variant
  4249   Term.variantlist	->  Name.variant_list
  4250   Term.invent_names	->  Name.invent_list
  4251 
  4252 Note that low-level renaming rarely occurs in new code -- operations
  4253 from structure Variable are used instead (see below).
  4254 
  4255 * Pure: structure Variable provides fundamental operations for proper
  4256 treatment of fixed/schematic variables in a context.  For example,
  4257 Variable.import introduces fixes for schematics of given facts and
  4258 Variable.export reverses the effect (up to renaming) -- this replaces
  4259 various freeze_thaw operations.
  4260 
  4261 * Pure: structure Goal provides simple interfaces for
  4262 init/conclude/finish and tactical prove operations (replacing former
  4263 Tactic.prove).  Goal.prove is the canonical way to prove results
  4264 within a given context; Goal.prove_global is a degraded version for
  4265 theory level goals, including a global Drule.standard.  Note that
  4266 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4267 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4268 in a locale context).
  4269 
  4270 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4271 and type checking (Syntax.check_term etc.), with common combinations
  4272 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4273 which are considered legacy and await removal.
  4274 
  4275 * Pure/Syntax: generic interfaces for type unchecking
  4276 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4277 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4278 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4279 available for convenience, but refer to the very same operations using
  4280 a mere theory instead of a full context.
  4281 
  4282 * Isar: simplified treatment of user-level errors, using exception
  4283 ERROR of string uniformly.  Function error now merely raises ERROR,
  4284 without any side effect on output channels.  The Isar toplevel takes
  4285 care of proper display of ERROR exceptions.  ML code may use plain
  4286 handle/can/try; cat_error may be used to concatenate errors like this:
  4287 
  4288   ... handle ERROR msg => cat_error msg "..."
  4289 
  4290 Toplevel ML code (run directly or through the Isar toplevel) may be
  4291 embedded into the Isar toplevel with exception display/debug like
  4292 this:
  4293 
  4294   Isar.toplevel (fn () => ...)
  4295 
  4296 INCOMPATIBILITY, removed special transform_error facilities, removed
  4297 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4298 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4299 -- use plain ERROR instead.
  4300 
  4301 * Isar: theory setup now has type (theory -> theory), instead of a
  4302 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4303 
  4304 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4305 ProofContext.debug/verbose flags.
  4306 
  4307 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4308 theory before entering a proof state.  Transactions now always see a
  4309 quasi-functional intermediate checkpoint, both in interactive and
  4310 batch mode.
  4311 
  4312 * Isar: simplified interfaces for outer syntax.  Renamed
  4313 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4314 OuterSyntax.add_parsers -- this functionality is now included in
  4315 OuterSyntax.command etc.  INCOMPATIBILITY.
  4316 
  4317 * Simplifier: the simpset of a running simplification process now
  4318 contains a proof context (cf. Simplifier.the_context), which is the
  4319 very context that the initial simpset has been retrieved from (by
  4320 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4321 (solver, looper etc.) may depend on arbitrary proof data.
  4322 
  4323 * Simplifier.inherit_context inherits the proof context (plus the
  4324 local bounds) of the current simplification process; any simproc
  4325 etc. that calls the Simplifier recursively should do this!  Removed
  4326 former Simplifier.inherit_bounds, which is already included here --
  4327 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4328 specify an explicit context using Simplifier.context/theory_context.
  4329 
  4330 * Simplifier/Classical Reasoner: more abstract interfaces
  4331 change_simpset/claset for modifying the simpset/claset reference of a
  4332 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4333 INCOMPATIBILITY.
  4334 
  4335 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4336 "Trueprop" etc.
  4337 
  4338 
  4339 *** System ***
  4340 
  4341 * settings: the default heap location within ISABELLE_HOME_USER now
  4342 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4343 Isabelle installations.
  4344 
  4345 * isabelle-process: option -S (secure mode) disables some critical
  4346 operations, notably runtime compilation and evaluation of ML source
  4347 code.
  4348 
  4349 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4350 
  4351 * Support for parallel execution, using native multicore support of
  4352 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4353 independent theories, according to the given theory header
  4354 specifications. The maximum number of worker threads is specified via
  4355 usedir option -M or the "max-threads" setting in Proof General. A
  4356 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4357 to 6 on a 8-core machine.  User-code needs to observe certain
  4358 guidelines for thread-safe programming, see appendix A in the Isar
  4359 Implementation manual.
  4360 
  4361 
  4362 
  4363 New in Isabelle2005 (October 2005)
  4364 ----------------------------------
  4365 
  4366 *** General ***
  4367 
  4368 * Theory headers: the new header syntax for Isar theories is
  4369 
  4370   theory <name>
  4371   imports <theory1> ... <theoryN>
  4372   uses <file1> ... <fileM>
  4373   begin
  4374 
  4375 where the 'uses' part is optional.  The previous syntax
  4376 
  4377   theory <name> = <theory1> + ... + <theoryN>:
  4378 
  4379 will disappear in the next release.  Use isatool fixheaders to convert
  4380 existing theory files.  Note that there is no change in ancient
  4381 non-Isar theories now, but these will disappear soon.
  4382 
  4383 * Theory loader: parent theories can now also be referred to via
  4384 relative and absolute paths.
  4385 
  4386 * Command 'find_theorems' searches for a list of criteria instead of a
  4387 list of constants. Known criteria are: intro, elim, dest, name:string,
  4388 simp:term, and any term. Criteria can be preceded by '-' to select
  4389 theorems that do not match. Intro, elim, dest select theorems that
  4390 match the current goal, name:s selects theorems whose fully qualified
  4391 name contain s, and simp:term selects all simplification rules whose
  4392 lhs match term.  Any other term is interpreted as pattern and selects
  4393 all theorems matching the pattern. Available in ProofGeneral under
  4394 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4395 
  4396   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4397 
  4398 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4399 matching the current goal as introduction rule and not having "HOL."
  4400 in their name (i.e. not being defined in theory HOL).
  4401 
  4402 * Command 'thms_containing' has been discontinued in favour of
  4403 'find_theorems'; INCOMPATIBILITY.
  4404 
  4405 * Communication with Proof General is now 8bit clean, which means that
  4406 Unicode text in UTF-8 encoding may be used within theory texts (both
  4407 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4408 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4409 
  4410   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4411   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4412 
  4413 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4414 Classical Reasoner.  Typical big applications run around 2 times
  4415 faster.
  4416 
  4417 
  4418 *** Document preparation ***
  4419 
  4420 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4421 of raw sources.  Only those symbols that do not require additional
  4422 LaTeX packages (depending on comments in isabellesym.sty) are
  4423 displayed properly, everything else is left verbatim.  isatool display
  4424 and isatool print are used as front ends (these are subject to the
  4425 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4426 
  4427 * Command tags control specific markup of certain regions of text,
  4428 notably folding and hiding.  Predefined tags include "theory" (for
  4429 theory begin and end), "proof" for proof commands, and "ML" for
  4430 commands involving ML code; the additional tags "visible" and
  4431 "invisible" are unused by default.  Users may give explicit tag
  4432 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4433 interpretation of tags is determined by the LaTeX job during document
  4434 preparation: see option -V of isatool usedir, or options -n and -t of
  4435 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4436 \isadroptag.
  4437 
  4438 Several document versions may be produced at the same time via isatool
  4439 usedir (the generated index.html will link all of them).  Typical
  4440 specifications include ''-V document=theory,proof,ML'' to present
  4441 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4442 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4443 these parts without any formal replacement text.  The Isabelle site
  4444 default settings produce ''document'' and ''outline'' versions as
  4445 specified above.
  4446 
  4447 * Several new antiquotations:
  4448 
  4449   @{term_type term} prints a term with its type annotated;
  4450 
  4451   @{typeof term} prints the type of a term;
  4452 
  4453   @{const const} is the same as @{term const}, but checks that the
  4454   argument is a known logical constant;
  4455 
  4456   @{term_style style term} and @{thm_style style thm} print a term or
  4457   theorem applying a "style" to it
  4458 
  4459   @{ML text}
  4460 
  4461 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4462 definitions, equations, inequations etc., 'concl' printing only the
  4463 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4464 to print the specified premise.  TermStyle.add_style provides an ML
  4465 interface for introducing further styles.  See also the "LaTeX Sugar"
  4466 document practical applications.  The ML antiquotation prints
  4467 type-checked ML expressions verbatim.
  4468 
  4469 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4470 and 'text' support optional locale specification '(in loc)', which
  4471 specifies the default context for interpreting antiquotations.  For
  4472 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4473 
  4474 * Option 'locale=NAME' of antiquotations specifies an alternative
  4475 context interpreting the subsequent argument.  For example: @{thm
  4476 [locale=lattice] inf_assoc}.
  4477 
  4478 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4479 a proof context.
  4480 
  4481 * Proper output of antiquotations for theory commands involving a
  4482 proof context (such as 'locale' or 'theorem (in loc) ...').
  4483 
  4484 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4485 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4486 
  4487 * isatool usedir: new option -C (default true) controls whether option
  4488 -D should include a copy of the original document directory; -C false
  4489 prevents unwanted effects such as copying of administrative CVS data.
  4490 
  4491 
  4492 *** Pure ***
  4493 
  4494 * Considerably improved version of 'constdefs' command.  Now performs
  4495 automatic type-inference of declared constants; additional support for
  4496 local structure declarations (cf. locales and HOL records), see also
  4497 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4498 sequential dependencies of definitions within a single 'constdefs'
  4499 section; moreover, the declared name needs to be an identifier.  If
  4500 all fails, consider to fall back on 'consts' and 'defs' separately.
  4501 
  4502 * Improved indexed syntax and implicit structures.  First of all,
  4503 indexed syntax provides a notational device for subscripted
  4504 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4505 expressions.  Secondly, in a local context with structure
  4506 declarations, number indexes \<^sub>n or the empty index (default
  4507 number 1) refer to a certain fixed variable implicitly; option
  4508 show_structs controls printing of implicit structures.  Typical
  4509 applications of these concepts involve record types and locales.
  4510 
  4511 * New command 'no_syntax' removes grammar declarations (and
  4512 translations) resulting from the given syntax specification, which is
  4513 interpreted in the same manner as for the 'syntax' command.
  4514 
  4515 * 'Advanced' translation functions (parse_translation etc.) may depend
  4516 on the signature of the theory context being presently used for
  4517 parsing/printing, see also isar-ref manual.
  4518 
  4519 * Improved 'oracle' command provides a type-safe interface to turn an
  4520 ML expression of type theory -> T -> term into a primitive rule of
  4521 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4522 is already included here); see also FOL/ex/IffExample.thy;
  4523 INCOMPATIBILITY.
  4524 
  4525 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4526 before); "cI" is no longer bound, use "c.intro" instead.
  4527 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4528 axclasses vs. locales.
  4529 
  4530 * Improved internal renaming of symbolic identifiers -- attach primes
  4531 instead of base 26 numbers.
  4532 
  4533 * New flag show_question_marks controls printing of leading question
  4534 marks in schematic variable names.
  4535 
  4536 * In schematic variable names, *any* symbol following \<^isub> or
  4537 \<^isup> is now treated as part of the base name.  For example, the
  4538 following works without printing of awkward ".0" indexes:
  4539 
  4540   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4541     by simp
  4542 
  4543 * Inner syntax includes (*(*nested*) comments*).
  4544 
  4545 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4546 annotations as "(00...)".
  4547 
  4548 * Clear separation of logical types and nonterminals, where the latter
  4549 may only occur in 'syntax' specifications or type abbreviations.
  4550 Before that distinction was only partially implemented via type class
  4551 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4552 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4553 exotic syntax specifications may require further adaption
  4554 (e.g. Cube/Cube.thy).
  4555 
  4556 * Removed obsolete type class "logic", use the top sort {} instead.
  4557 Note that non-logical types should be declared as 'nonterminals'
  4558 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4559 specifications.
  4560 
  4561 * Attributes 'induct' and 'cases': type or set names may now be
  4562 locally fixed variables as well.
  4563 
  4564 * Simplifier: can now control the depth to which conditional rewriting
  4565 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4566 Limit.
  4567 
  4568 * Simplifier: simplification procedures may now take the current
  4569 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4570 interface), which is very useful for calling the Simplifier
  4571 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4572 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4573 low-level mk_simproc no longer applies Logic.varify internally, to
  4574 allow for use in a context of fixed variables.
  4575 
  4576 * thin_tac now works even if the assumption being deleted contains !!
  4577 or ==>.  More generally, erule now works even if the major premise of
  4578 the elimination rule contains !! or ==>.
  4579 
  4580 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4581 
  4582 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4583 from Pure, which contains all common declarations already.  Both
  4584 theories are defined via plain Isabelle/Isar .thy files.
  4585 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4586 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4587 use isatool fixcpure to adapt your theory and ML sources.
  4588 
  4589 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4590 selections of theorems in named facts via index ranges.
  4591 
  4592 * 'print_theorems': in theory mode, really print the difference
  4593 wrt. the last state (works for interactive theory development only),
  4594 in proof mode print all local facts (cf. 'print_facts');
  4595 
  4596 * 'hide': option '(open)' hides only base names.
  4597 
  4598 * More efficient treatment of intermediate checkpoints in interactive
  4599 theory development.
  4600 
  4601 * Code generator is now invoked via code_module (incremental code
  4602 generation) and code_library (modular code generation, ML structures
  4603 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4604 must be quoted when used as identifiers.
  4605 
  4606 * New 'value' command for reading, evaluating and printing terms using
  4607 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4608 quoted when used as identifier.
  4609 
  4610 
  4611 *** Locales ***
  4612 
  4613 * New commands for the interpretation of locale expressions in
  4614 theories (1), locales (2) and proof contexts (3).  These generate
  4615 proof obligations from the expression specification.  After the
  4616 obligations have been discharged, theorems of the expression are added
  4617 to the theory, target locale or proof context.  The synopsis of the
  4618 commands is a follows:
  4619 
  4620   (1) interpretation expr inst
  4621   (2) interpretation target < expr
  4622   (3) interpret expr inst
  4623 
  4624 Interpretation in theories and proof contexts require a parameter
  4625 instantiation of terms from the current context.  This is applied to
  4626 specifications and theorems of the interpreted expression.
  4627 Interpretation in locales only permits parameter renaming through the
  4628 locale expression.  Interpretation is smart in that interpretations
  4629 that are active already do not occur in proof obligations, neither are
  4630 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4631 inspect active interpretations of a particular locale.  For details,
  4632 see the Isar Reference manual.  Examples can be found in
  4633 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4634 
  4635 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4636 'interpret' instead.
  4637 
  4638 * New context element 'constrains' for adding type constraints to
  4639 parameters.
  4640 
  4641 * Context expressions: renaming of parameters with syntax
  4642 redeclaration.
  4643 
  4644 * Locale declaration: 'includes' disallowed.
  4645 
  4646 * Proper static binding of attribute syntax -- i.e. types / terms /
  4647 facts mentioned as arguments are always those of the locale definition
  4648 context, independently of the context of later invocations.  Moreover,
  4649 locale operations (renaming and type / term instantiation) are applied
  4650 to attribute arguments as expected.
  4651 
  4652 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4653 actual attributes; rare situations may require Attrib.attribute to
  4654 embed those attributes into Attrib.src that lack concrete syntax.
  4655 Attribute implementations need to cooperate properly with the static
  4656 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4657 Attrib.XXX_thm etc. already do the right thing without further
  4658 intervention.  Only unusual applications -- such as "where" or "of"
  4659 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4660 on the context and the facts involved -- may have to assign parsed
  4661 values to argument tokens explicitly.
  4662 
  4663 * Changed parameter management in theorem generation for long goal
  4664 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4665 theorem statement in rare situations.
  4666 
  4667 * Locale inspection command 'print_locale' omits notes elements.  Use
  4668 'print_locale!' to have them included in the output.
  4669 
  4670 
  4671 *** Provers ***
  4672 
  4673 * Provers/hypsubst.ML: improved version of the subst method, for
  4674 single-step rewriting: it now works in bound variable contexts. New is
  4675 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4676 rewrite a different subterm than the original subst method, which is
  4677 still available as 'simplesubst'.
  4678 
  4679 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4680 and quasi orders.
  4681 
  4682 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4683 reflexive-transitive closure of relations.
  4684 
  4685 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4686 limit (previously hard-coded with a value of 20) user-definable.
  4687 
  4688 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4689 is peformed already.  Object-logics merely need to finish their
  4690 initial simpset configuration as before.  INCOMPATIBILITY.
  4691 
  4692 
  4693 *** HOL ***
  4694 
  4695 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4696 
  4697   syntax (epsilon)
  4698     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4699 
  4700 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4701 and x-symbol; use option '-m epsilon' to get it actually printed.
  4702 Moreover, the mathematically important symbolic identifier \<epsilon>
  4703 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4704 
  4705 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4706 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4707 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4708 support corresponding Isar calculations.
  4709 
  4710 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4711 instead of ":".
  4712 
  4713 * theory SetInterval: changed the syntax for open intervals:
  4714 
  4715   Old       New
  4716   {..n(}    {..<n}
  4717   {)n..}    {n<..}
  4718   {m..n(}   {m..<n}
  4719   {)m..n}   {m<..n}
  4720   {)m..n(}  {m<..<n}
  4721 
  4722 The old syntax is still supported but will disappear in the next
  4723 release.  For conversion use the following Emacs search and replace
  4724 patterns (these are not perfect but work quite well):
  4725 
  4726   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4727   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4728 
  4729 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4730 equalities in commutative rings; method 'algebra' provides a generic
  4731 interface.
  4732 
  4733 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4734 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4735 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4736 be a tuple pattern.
  4737 
  4738 Some new syntax forms are available:
  4739 
  4740   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4741   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4742   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4743   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4744 
  4745 The latter form "\<Sum>x < k. e" used to be based on a separate
  4746 function "Summation", which has been discontinued.
  4747 
  4748 * theory Finite_Set: in structured induction proofs, the insert case
  4749 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4750 (insert F x)'.
  4751 
  4752 * The 'refute' command has been extended to support a much larger
  4753 fragment of HOL, including axiomatic type classes, constdefs and
  4754 typedefs, inductive datatypes and recursion.
  4755 
  4756 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4757 Requires zChaff with proof generation to be installed.  See
  4758 HOL/ex/SAT_Examples.thy for examples.
  4759 
  4760 * Datatype induction via method 'induct' now preserves the name of the
  4761 induction variable. For example, when proving P(xs::'a list) by
  4762 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4763 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4764 in unstructured proof scripts.
  4765 
  4766 * Reworked implementation of records.  Improved scalability for
  4767 records with many fields, avoiding performance problems for type
  4768 inference. Records are no longer composed of nested field types, but
  4769 of nested extension types. Therefore the record type only grows linear
  4770 in the number of extensions and not in the number of fields.  The
  4771 top-level (users) view on records is preserved.  Potential
  4772 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4773 old record representation. The type generated for a record is called
  4774 <record_name>_ext_type.
  4775 
  4776 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4777 proofs triggered by a record definition or a simproc (if
  4778 quick_and_dirty is enabled).  Definitions of large records can take
  4779 quite long.
  4780 
  4781 New simproc record_upd_simproc for simplification of multiple record
  4782 updates enabled by default.  Moreover, trivial updates are also
  4783 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4784 occasionally, since simplification is more powerful by default.
  4785 
  4786 * typedef: proper support for polymorphic sets, which contain extra
  4787 type-variables in the term.
  4788 
  4789 * Simplifier: automatically reasons about transitivity chains
  4790 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4791 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4792 old proofs break occasionally as simplification may now solve more
  4793 goals than previously.
  4794 
  4795 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4796 present.  Works for all partial orders (class "order"), in particular
  4797 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4798 just like y <= x.
  4799 
  4800 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4801 bound variable or a constant then the let is unfolded.  Otherwise
  4802 first a is simplified to b, and then f b is simplified to g. If
  4803 possible we abstract b from g arriving at "let x = b in h x",
  4804 otherwise we unfold the let and arrive at g.  The simproc can be
  4805 enabled/disabled by the reference use_let_simproc.  Potential
  4806 INCOMPATIBILITY since simplification is more powerful by default.
  4807 
  4808 * Classical reasoning: the meson method now accepts theorems as arguments.
  4809 
  4810 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4811 jobs to provide advice on the provability of subgoals.
  4812 
  4813 * Theory OrderedGroup and Ring_and_Field: various additions and
  4814 improvements to faciliate calculations involving equalities and
  4815 inequalities.
  4816 
  4817 The following theorems have been eliminated or modified
  4818 (INCOMPATIBILITY):
  4819 
  4820   abs_eq             now named abs_of_nonneg
  4821   abs_of_ge_0        now named abs_of_nonneg
  4822   abs_minus_eq       now named abs_of_nonpos
  4823   imp_abs_id         now named abs_of_nonneg
  4824   imp_abs_neg_id     now named abs_of_nonpos
  4825   mult_pos           now named mult_pos_pos
  4826   mult_pos_le        now named mult_nonneg_nonneg
  4827   mult_pos_neg_le    now named mult_nonneg_nonpos
  4828   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4829   mult_neg           now named mult_neg_neg
  4830   mult_neg_le        now named mult_nonpos_nonpos
  4831 
  4832 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4833      
  4834      zero_le_square
  4835      not_square_less_zero 
  4836 
  4837   The following lemmas have been deleted from Real/RealPow:
  4838   
  4839      realpow_zero_zero
  4840      realpow_two
  4841      realpow_less
  4842      zero_le_power
  4843      realpow_two_le
  4844      abs_realpow_two
  4845      realpow_two_abs     
  4846 
  4847 * Theory Parity: added rules for simplifying exponents.
  4848 
  4849 * Theory List:
  4850 
  4851 The following theorems have been eliminated or modified
  4852 (INCOMPATIBILITY):
  4853 
  4854   list_all_Nil       now named list_all.simps(1)
  4855   list_all_Cons      now named list_all.simps(2)
  4856   list_all_conv      now named list_all_iff
  4857   set_mem_eq         now named mem_iff
  4858 
  4859 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4860 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4861 
  4862 
  4863 *** HOL-Complex ***
  4864 
  4865 * Theory RealDef: better support for embedding natural numbers and
  4866 integers in the reals.
  4867 
  4868 The following theorems have been eliminated or modified
  4869 (INCOMPATIBILITY):
  4870 
  4871   exp_ge_add_one_self  now requires no hypotheses
  4872   real_of_int_add      reversed direction of equality (use [symmetric])
  4873   real_of_int_minus    reversed direction of equality (use [symmetric])
  4874   real_of_int_diff     reversed direction of equality (use [symmetric])
  4875   real_of_int_mult     reversed direction of equality (use [symmetric])
  4876 
  4877 * Theory RComplete: expanded support for floor and ceiling functions.
  4878 
  4879 * Theory Ln is new, with properties of the natural logarithm
  4880 
  4881 * Hyperreal: There is a new type constructor "star" for making
  4882 nonstandard types.  The old type names are now type synonyms:
  4883 
  4884   hypreal = real star
  4885   hypnat = nat star
  4886   hcomplex = complex star
  4887 
  4888 * Hyperreal: Many groups of similarly-defined constants have been
  4889 replaced by polymorphic versions (INCOMPATIBILITY):
  4890 
  4891   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4892 
  4893   starset      <-- starsetNat, starsetC
  4894   *s*          <-- *sNat*, *sc*
  4895   starset_n    <-- starsetNat_n, starsetC_n
  4896   *sn*         <-- *sNatn*, *scn*
  4897   InternalSets <-- InternalNatSets, InternalCSets
  4898 
  4899   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4900   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4901   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4902   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4903   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4904 
  4905 * Hyperreal: Many type-specific theorems have been removed in favor of
  4906 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4907 
  4908   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4909   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4910   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4911   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4912   right_minus <-- hypreal_add_minus
  4913   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4914   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4915   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4916   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4917   mult_1_right <-- hcomplex_mult_one_right
  4918   mult_zero_left <-- hcomplex_mult_zero_left
  4919   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4920   right_distrib <-- hypnat_add_mult_distrib2
  4921   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4922   right_inverse <-- hypreal_mult_inverse
  4923   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4924   order_refl <-- {hypreal,hypnat}_le_refl
  4925   order_trans <-- {hypreal,hypnat}_le_trans
  4926   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4927   order_less_le <-- {hypreal,hypnat}_less_le
  4928   linorder_linear <-- {hypreal,hypnat}_le_linear
  4929   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4930   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4931   add_nonneg_nonneg <-- hypreal_le_add_order
  4932 
  4933 * Hyperreal: Separate theorems having to do with type-specific
  4934 versions of constants have been merged into theorems that apply to the
  4935 new polymorphic constants (INCOMPATIBILITY):
  4936 
  4937   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4938   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4939   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4940   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4941   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4942   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4943   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4944   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4945   STAR_diff <-- {STAR,STARC}_diff
  4946   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4947     STARC_hcomplex_of_complex}_image_subset
  4948   starset_n_Un <-- starset{Nat,C}_n_Un
  4949   starset_n_Int <-- starset{Nat,C}_n_Int
  4950   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4951   starset_n_diff <-- starset{Nat,C}_n_diff
  4952   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4953   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4954   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4955   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4956   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4957   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4958   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4959   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4960   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4961   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4962   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4963   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4964   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4965   starfun_diff <-- starfun{C,RC,CR}_diff
  4966   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4967   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4968   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4969   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4970   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4971   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4972   starfun_Id <-- starfunC_Id
  4973   starfun_approx <-- starfun{Nat,CR}_approx
  4974   starfun_capprox <-- starfun{C,RC}_capprox
  4975   starfun_abs <-- starfunNat_rabs
  4976   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4977   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4978   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4979   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4980   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4981   starfun_add_approx <-- starfunCR_add_approx
  4982   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4983   starfun_divide <-- starfun{C,CR,RC}_divide
  4984   starfun_n <-- starfun{Nat,C}_n
  4985   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4986   starfun_n_add <-- starfun{Nat,C}_n_add
  4987   starfun_n_add_minus <-- starfunNat_n_add_minus
  4988   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4989   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4990   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4991 
  4992   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4993   star_n_minus <-- {hypreal,hcomplex}_minus
  4994   star_n_diff <-- {hypreal,hcomplex}_diff
  4995   star_n_mult <-- {hypreal,hcomplex}_mult
  4996   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4997   star_n_le <-- {hypreal,hypnat}_le
  4998   star_n_less <-- {hypreal,hypnat}_less
  4999   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5000   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5001   star_n_abs <-- hypreal_hrabs
  5002   star_n_divide <-- hcomplex_divide
  5003 
  5004   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5005   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5006   star_of_diff <-- hypreal_of_real_diff
  5007   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5008   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5009   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5010   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5011   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5012   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5013   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5014   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5015   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5016   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5017   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5018   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5019   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5020   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5021   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5022   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5023   star_of_power <-- hypreal_of_real_power
  5024   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5025 
  5026 * Hyperreal: new method "transfer" that implements the transfer
  5027 principle of nonstandard analysis. With a subgoal that mentions
  5028 nonstandard types like "'a star", the command "apply transfer"
  5029 replaces it with an equivalent one that mentions only standard types.
  5030 To be successful, all free variables must have standard types; non-
  5031 standard variables must have explicit universal quantifiers.
  5032 
  5033 * Hyperreal: A theory of Taylor series.
  5034 
  5035 
  5036 *** HOLCF ***
  5037 
  5038 * Discontinued special version of 'constdefs' (which used to support
  5039 continuous functions) in favor of the general Pure one with full
  5040 type-inference.
  5041 
  5042 * New simplification procedure for solving continuity conditions; it
  5043 is much faster on terms with many nested lambda abstractions (cubic
  5044 instead of exponential time).
  5045 
  5046 * New syntax for domain package: selector names are now optional.
  5047 Parentheses should be omitted unless argument is lazy, for example:
  5048 
  5049   domain 'a stream = cons "'a" (lazy "'a stream")
  5050 
  5051 * New command 'fixrec' for defining recursive functions with pattern
  5052 matching; defining multiple functions with mutual recursion is also
  5053 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5054 sinr, or any data constructor defined by the domain package. The given
  5055 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5056 syntax and examples.
  5057 
  5058 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5059 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5060 but the proof obligation additionally includes an admissibility
  5061 requirement. The packages generate instances of class cpo or pcpo,
  5062 with continuity and strictness theorems for Rep and Abs.
  5063 
  5064 * HOLCF: Many theorems have been renamed according to a more standard naming
  5065 scheme (INCOMPATIBILITY):
  5066 
  5067   foo_inject:  "foo$x = foo$y ==> x = y"
  5068   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5069   foo_less:    "(foo$x << foo$y) = (x << y)"
  5070   foo_strict:  "foo$UU = UU"
  5071   foo_defined: "... ==> foo$x ~= UU"
  5072   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5073 
  5074 
  5075 *** ZF ***
  5076 
  5077 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5078 including the First Isomorphism Theorem (on quotienting by the kernel
  5079 of a homomorphism).
  5080 
  5081 * ZF/Simplifier: install second copy of type solver that actually
  5082 makes use of TC rules declared to Isar proof contexts (or locales);
  5083 the old version is still required for ML proof scripts.
  5084 
  5085 
  5086 *** Cube ***
  5087 
  5088 * Converted to Isar theory format; use locales instead of axiomatic
  5089 theories.
  5090 
  5091 
  5092 *** ML ***
  5093 
  5094 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5095 for ||>, ||>>, |>>,
  5096 
  5097 * Pure/library.ML no longer defines its own option datatype, but uses
  5098 that of the SML basis, which has constructors NONE and SOME instead of
  5099 None and Some, as well as exception Option.Option instead of OPTION.
  5100 The functions the, if_none, is_some, is_none have been adapted
  5101 accordingly, while Option.map replaces apsome.
  5102 
  5103 * Pure/library.ML: the exception LIST has been given up in favour of
  5104 the standard exceptions Empty and Subscript, as well as
  5105 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5106 superceded by the standard hd and tl functions etc.
  5107 
  5108 A number of basic list functions are no longer exported to the ML
  5109 toplevel, as they are variants of predefined functions.  The following
  5110 suggests how one can translate existing code:
  5111 
  5112     rev_append xs ys = List.revAppend (xs, ys)
  5113     nth_elem (i, xs) = List.nth (xs, i)
  5114     last_elem xs = List.last xs
  5115     flat xss = List.concat xss
  5116     seq fs = List.app fs
  5117     partition P xs = List.partition P xs
  5118     mapfilter f xs = List.mapPartial f xs
  5119 
  5120 * Pure/library.ML: several combinators for linear functional
  5121 transformations, notably reverse application and composition:
  5122 
  5123   x |> f                f #> g
  5124   (x, y) |-> f          f #-> g
  5125 
  5126 * Pure/library.ML: introduced/changed precedence of infix operators:
  5127 
  5128   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5129   infix 2 ?;
  5130   infix 3 o oo ooo oooo;
  5131   infix 4 ~~ upto downto;
  5132 
  5133 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5134 infix operators.
  5135 
  5136 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5137 fold_map support linear functional transformations and nesting.  For
  5138 example:
  5139 
  5140   fold f [x1, ..., xN] y =
  5141     y |> f x1 |> ... |> f xN
  5142 
  5143   (fold o fold) f [xs1, ..., xsN] y =
  5144     y |> fold f xs1 |> ... |> fold f xsN
  5145 
  5146   fold f [x1, ..., xN] =
  5147     f x1 #> ... #> f xN
  5148 
  5149   (fold o fold) f [xs1, ..., xsN] =
  5150     fold f xs1 #> ... #> fold f xsN
  5151 
  5152 * Pure/library.ML: the following selectors on type 'a option are
  5153 available:
  5154 
  5155   the:               'a option -> 'a  (*partial*)
  5156   these:             'a option -> 'a  where 'a = 'b list
  5157   the_default: 'a -> 'a option -> 'a
  5158   the_list:          'a option -> 'a list
  5159 
  5160 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5161 basic operations for association lists, following natural argument
  5162 order; moreover the explicit equality predicate passed here avoids
  5163 potentially expensive polymorphic runtime equality checks.
  5164 The old functions may be expressed as follows:
  5165 
  5166   assoc = uncurry (AList.lookup (op =))
  5167   assocs = these oo AList.lookup (op =)
  5168   overwrite = uncurry (AList.update (op =)) o swap
  5169 
  5170 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5171 
  5172   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5173   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5174 
  5175 replacing make_keylist and keyfilter (occassionally used)
  5176 Naive rewrites:
  5177 
  5178   make_keylist = AList.make
  5179   keyfilter = AList.find (op =)
  5180 
  5181 * eq_fst and eq_snd now take explicit equality parameter, thus
  5182   avoiding eqtypes. Naive rewrites:
  5183 
  5184     eq_fst = eq_fst (op =)
  5185     eq_snd = eq_snd (op =)
  5186 
  5187 * Removed deprecated apl and apr (rarely used).
  5188   Naive rewrites:
  5189 
  5190     apl (n, op) =>>= curry op n
  5191     apr (op, m) =>>= fn n => op (n, m)
  5192 
  5193 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5194 provides a reasonably efficient light-weight implementation of sets as
  5195 lists.
  5196 
  5197 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5198 few new operations; existing lookup and update are now curried to
  5199 follow natural argument order (for use with fold etc.);
  5200 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5201 
  5202 * Pure/General: output via the Isabelle channels of
  5203 writeln/warning/error etc. is now passed through Output.output, with a
  5204 hook for arbitrary transformations depending on the print_mode
  5205 (cf. Output.add_mode -- the first active mode that provides a output
  5206 function wins).  Already formatted output may be embedded into further
  5207 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5208 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5209 accommodate easy composition of diagnostic messages etc.  Programmers
  5210 rarely need to care about Output.output or Output.raw at all, with
  5211 some notable exceptions: Output.output is required when bypassing the
  5212 standard channels (writeln etc.), or in token translations to produce
  5213 properly formatted results; Output.raw is required when capturing
  5214 already output material that will eventually be presented to the user
  5215 a second time.  For the default print mode, both Output.output and
  5216 Output.raw have no effect.
  5217 
  5218 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5219 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5220 cumulative results are displayed at the end of a batch session.
  5221 
  5222 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5223 replaced by File.platform_path and File.shell_path (with appropriate
  5224 hooks).  This provides a clean interface for unusual systems where the
  5225 internal and external process view of file names are different.
  5226 
  5227 * Pure: more efficient orders for basic syntactic entities: added
  5228 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5229 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5230 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5231 orders now -- potential INCOMPATIBILITY for code that depends on a
  5232 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5233 Library.sort_strings on result).
  5234 
  5235 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5236 fold_types traverse types/terms from left to right, observing natural
  5237 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5238 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5239 
  5240 * Pure: name spaces have been refined, with significant changes of the
  5241 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5242 to extern(_table).  The plain name entry path is superceded by a
  5243 general 'naming' context, which also includes the 'policy' to produce
  5244 a fully qualified name and external accesses of a fully qualified
  5245 name; NameSpace.extend is superceded by context dependent
  5246 Sign.declare_name.  Several theory and proof context operations modify
  5247 the naming context.  Especially note Theory.restore_naming and
  5248 ProofContext.restore_naming to get back to a sane state; note that
  5249 Theory.add_path is no longer sufficient to recover from
  5250 Theory.absolute_path in particular.
  5251 
  5252 * Pure: new flags short_names (default false) and unique_names
  5253 (default true) for controlling output of qualified names.  If
  5254 short_names is set, names are printed unqualified.  If unique_names is
  5255 reset, the name prefix is reduced to the minimum required to achieve
  5256 the original result when interning again, even if there is an overlap
  5257 with earlier declarations.
  5258 
  5259 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5260 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5261 (useful for printing error messages).  INCOMPATIBILITY.
  5262 
  5263 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5264 Theory.theory are now identified, referring to the universal
  5265 Context.theory (see Pure/context.ML).  Actual signature and theory
  5266 content is managed as theory data.  The old code and interfaces were
  5267 spread over many files and structures; the new arrangement introduces
  5268 considerable INCOMPATIBILITY to gain more clarity:
  5269 
  5270   Context -- theory management operations (name, identity, inclusion,
  5271     parents, ancestors, merge, etc.), plus generic theory data;
  5272 
  5273   Sign -- logical signature and syntax operations (declaring consts,
  5274     types, etc.), plus certify/read for common entities;
  5275 
  5276   Theory -- logical theory operations (stating axioms, definitions,
  5277     oracles), plus a copy of logical signature operations (consts,
  5278     types, etc.); also a few basic management operations (Theory.copy,
  5279     Theory.merge, etc.)
  5280 
  5281 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5282 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5283 for convenience -- they merely return the theory.
  5284 
  5285 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5286 
  5287 * Pure: the Isar proof context type is already defined early in Pure
  5288 as Context.proof (note that ProofContext.context and Proof.context are
  5289 aliases, where the latter is the preferred name).  This enables other
  5290 Isabelle components to refer to that type even before Isar is present.
  5291 
  5292 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5293 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5294 any of these kinds.  For example, Sign.intern typeK is now
  5295 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5296 Theory.hide_types.  Also note that former
  5297 Theory.hide_classes/types/consts are now
  5298 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5299 internalize their arguments!  INCOMPATIBILITY.
  5300 
  5301 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5302 datatype thmref (with constructors Name and NameSelection) instead of
  5303 plain string -- INCOMPATIBILITY;
  5304 
  5305 * Pure: cases produced by proof methods specify options, where NONE
  5306 means to remove case bindings -- INCOMPATIBILITY in
  5307 (RAW_)METHOD_CASES.
  5308 
  5309 * Pure: the following operations retrieve axioms or theorems from a
  5310 theory node or theory hierarchy, respectively:
  5311 
  5312   Theory.axioms_of: theory -> (string * term) list
  5313   Theory.all_axioms_of: theory -> (string * term) list
  5314   PureThy.thms_of: theory -> (string * thm) list
  5315   PureThy.all_thms_of: theory -> (string * thm) list
  5316 
  5317 * Pure: print_tac now outputs the goal through the trace channel.
  5318 
  5319 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5320 Reference Toplevel.debug (default false) controls detailed printing
  5321 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5322 controls execution profiling -- set to 1 for time and 2 for space
  5323 (both increase the runtime).
  5324 
  5325 * Isar session: The initial use of ROOT.ML is now always timed,
  5326 i.e. the log will show the actual process times, in contrast to the
  5327 elapsed wall-clock time that the outer shell wrapper produces.
  5328 
  5329 * Simplifier: improved handling of bound variables (nameless
  5330 representation, avoid allocating new strings).  Simprocs that invoke
  5331 the Simplifier recursively should use Simplifier.inherit_bounds to
  5332 avoid local name clashes.  Failure to do so produces warnings
  5333 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5334 for further details.
  5335 
  5336 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5337 bindings for all theorems stored within a given theory; this may help
  5338 in porting non-Isar theories to Isar ones, while keeping ML proof
  5339 scripts for the time being.
  5340 
  5341 * ML operator HTML.with_charset specifies the charset begin used for
  5342 generated HTML files.  For example:
  5343 
  5344   HTML.with_charset "utf-8" use_thy "Hebrew";
  5345   HTML.with_charset "utf-8" use_thy "Chinese";
  5346 
  5347 
  5348 *** System ***
  5349 
  5350 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5351 isabelle, isatool etc.).
  5352 
  5353 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5354 isatool doc, isatool mkdir, display_drafts etc.).
  5355 
  5356 * isatool usedir: option -f allows specification of the ML file to be
  5357 used by Isabelle; default is ROOT.ML.
  5358 
  5359 * New isatool version outputs the version identifier of the Isabelle
  5360 distribution being used.
  5361 
  5362 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5363 (containing Boolean satisfiability problems) into Isabelle/HOL
  5364 theories.
  5365 
  5366 
  5367 
  5368 New in Isabelle2004 (April 2004)
  5369 --------------------------------
  5370 
  5371 *** General ***
  5372 
  5373 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5374   Replaces linorder.ML.
  5375 
  5376 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5377   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5378   (\<a>...\<z>), are now considered normal letters, and can therefore
  5379   be used anywhere where an ASCII letter (a...zA...Z) has until
  5380   now. COMPATIBILITY: This obviously changes the parsing of some
  5381   terms, especially where a symbol has been used as a binder, say
  5382   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5383   as an identifier.  Fix it by inserting a space around former
  5384   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5385   existing theory and ML files.
  5386 
  5387 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5388 
  5389 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5390   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5391   a normal (but invisible) letter. For multiple letter subscripts repeat
  5392   \<^isub> like this: x\<^isub>1\<^isub>2.
  5393 
  5394 * Pure: There are now sub-/superscripts that can span more than one
  5395   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5396   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5397   superscript. The new control characters are not identifier parts.
  5398 
  5399 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5400   content of "..." to the latex file instead of \isacntrl... . The "..."
  5401   may consist of any printable characters excluding the end bracket >.
  5402 
  5403 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5404   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5405   declare constants "final", which prevents their being given a definition
  5406   later.  It is useful for constants whose behaviour is fixed axiomatically
  5407   rather than definitionally, such as the meta-logic connectives.
  5408 
  5409 * Pure: 'instance' now handles general arities with general sorts
  5410   (i.e. intersections of classes),
  5411 
  5412 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5413   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5414   It can be changed to alter the colors/layout of generated pages.
  5415 
  5416 
  5417 *** Isar ***
  5418 
  5419 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5420   cut_tac, subgoal_tac and thin_tac:
  5421   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5422     locales are no longer forced to write Isar proof scripts.
  5423     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5424     emulations.
  5425   - INCOMPATIBILITY: names of variables to be instantiated may no
  5426     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5427     This is consistent with the instantiation attribute "where".
  5428 
  5429 * Attributes "where" and "of":
  5430   - Now take type variables of instantiated theorem into account when reading
  5431     the instantiation string.  This fixes a bug that caused instantiated
  5432     theorems to have too special types in some circumstances.
  5433   - "where" permits explicit instantiations of type variables.
  5434 
  5435 * Calculation commands "moreover" and "also" no longer interfere with
  5436   current facts ("this"), admitting arbitrary combinations with "then"
  5437   and derived forms.
  5438 
  5439 * Locales:
  5440   - Goal statements involving the context element "includes" no longer
  5441     generate theorems with internal delta predicates (those ending on
  5442     "_axioms") in the premise.
  5443     Resolve particular premise with <locale>.intro to obtain old form.
  5444   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5445     specification and "includes" elements in goal statement.
  5446   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5447     [intro?] and [elim?] (respectively) by default.
  5448   - Experimental command for instantiation of locales in proof contexts:
  5449         instantiate <label>[<attrs>]: <loc>
  5450     Instantiates locale <loc> and adds all its theorems to the current context
  5451     taking into account their attributes.  Label and attrs are optional
  5452     modifiers, like in theorem declarations.  If present, names of
  5453     instantiated theorems are qualified with <label>, and the attributes
  5454     <attrs> are applied after any attributes these theorems might have already.
  5455       If the locale has assumptions, a chained fact of the form
  5456     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5457     are derived.  The command does not support old-style locales declared
  5458     with "locale (open)".
  5459       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5460 
  5461 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5462   (Isar) contexts.
  5463 
  5464 
  5465 *** HOL ***
  5466 
  5467 * Proof import: new image HOL4 contains the imported library from
  5468   the HOL4 system with about 2500 theorems. It is imported by
  5469   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5470   can be used like any other Isabelle image.  See
  5471   HOL/Import/HOL/README for more information.
  5472 
  5473 * Simplifier:
  5474   - Much improved handling of linear and partial orders.
  5475     Reasoners for linear and partial orders are set up for type classes
  5476     "linorder" and "order" respectively, and are added to the default simpset
  5477     as solvers.  This means that the simplifier can build transitivity chains
  5478     to solve goals from the assumptions.
  5479   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5480     of blast or auto after simplification become unnecessary because the goal
  5481     is solved by simplification already.
  5482 
  5483 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5484     all proved in axiomatic type classes for semirings, rings and fields.
  5485 
  5486 * Numerics:
  5487   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5488     now formalized using the Ring_and_Field theory mentioned above.
  5489   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5490     than before, because now they are set up once in a generic manner.
  5491   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5492     Look for the general versions in Ring_and_Field (and Power if they concern
  5493     exponentiation).
  5494 
  5495 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5496 
  5497 * Records:
  5498   - Record types are now by default printed with their type abbreviation
  5499     instead of the list of all field types. This can be configured via
  5500     the reference "print_record_type_abbr".
  5501   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5502     (not enabled by default).
  5503   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5504     EX x. x = sel r to True (not enabled by default).
  5505   - Tactic "record_split_simp_tac" to split and simplify records added.
  5506 
  5507 * 'specification' command added, allowing for definition by
  5508   specification.  There is also an 'ax_specification' command that
  5509   introduces the new constants axiomatically.
  5510 
  5511 * arith(_tac) is now able to generate counterexamples for reals as well.
  5512 
  5513 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5514 
  5515 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5516   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5517 
  5518 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5519   matrix theory to linear programming.
  5520 
  5521 * Unions and Intersections:
  5522   The latex output syntax of UN and INT has been changed
  5523   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5524   i.e. the index formulae has become a subscript.
  5525   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5526 
  5527 * Unions and Intersections over Intervals:
  5528   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5529   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5530   like in normal math, and corresponding versions for < and for intersection.
  5531 
  5532 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5533   lexicographic dictonary ordering has been added as "lexord".
  5534 
  5535 * ML: the legacy theory structures Int and List have been removed. They had
  5536   conflicted with ML Basis Library structures having the same names.
  5537 
  5538 * 'refute' command added to search for (finite) countermodels.  Only works
  5539   for a fragment of HOL.  The installation of an external SAT solver is
  5540   highly recommended.  See "HOL/Refute.thy" for details.
  5541 
  5542 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5543   formulae under an assignment of free variables to random values.
  5544   In contrast to 'refute', it can deal with inductive datatypes,
  5545   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5546   for examples.
  5547 
  5548 
  5549 *** HOLCF ***
  5550 
  5551 * Streams now come with concatenation and are part of the HOLCF image
  5552 
  5553 
  5554 
  5555 New in Isabelle2003 (May 2003)
  5556 ------------------------------
  5557 
  5558 *** General ***
  5559 
  5560 * Provers/simplifier:
  5561 
  5562   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5563     Assumptions are now subject to complete mutual simplification,
  5564     not just from left to right. The simplifier now preserves
  5565     the order of assumptions.
  5566 
  5567     Potential INCOMPATIBILITY:
  5568 
  5569     -- simp sometimes diverges where the old version did
  5570        not, e.g. invoking simp on the goal
  5571 
  5572         [| P (f x); y = x; f x = f y |] ==> Q
  5573 
  5574        now gives rise to the infinite reduction sequence
  5575 
  5576         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5577 
  5578        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5579        kind of problem.
  5580 
  5581     -- Tactics combining classical reasoner and simplification (such as auto)
  5582        are also affected by this change, because many of them rely on
  5583        simp. They may sometimes diverge as well or yield a different numbers
  5584        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5585        in case of problems. Sometimes subsequent calls to the classical
  5586        reasoner will fail because a preceeding call to the simplifier too
  5587        eagerly simplified the goal, e.g. deleted redundant premises.
  5588 
  5589   - The simplifier trace now shows the names of the applied rewrite rules
  5590 
  5591   - You can limit the number of recursive invocations of the simplifier
  5592     during conditional rewriting (where the simplifie tries to solve the
  5593     conditions before applying the rewrite rule):
  5594     ML "simp_depth_limit := n"
  5595     where n is an integer. Thus you can force termination where previously
  5596     the simplifier would diverge.
  5597 
  5598   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5599 
  5600   - No longer aborts on failed congruence proof.  Instead, the
  5601     congruence is ignored.
  5602 
  5603 * Pure: New generic framework for extracting programs from constructive
  5604   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5605   as HOL/Extraction for some case studies.
  5606 
  5607 * Pure: The main goal of the proof state is no longer shown by default, only
  5608 the subgoals. This behaviour is controlled by a new flag.
  5609    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5610 (ML: Proof.show_main_goal).
  5611 
  5612 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5613 rules whose conclusion matches subgoal 1:
  5614       PG menu: Isabelle/Isar -> Show me -> matching rules
  5615 The rules are ordered by how closely they match the subgoal.
  5616 In particular, rules that solve a subgoal outright are displayed first
  5617 (or rather last, the way they are printed).
  5618 (ML: ProofGeneral.print_intros())
  5619 
  5620 * Pure: New flag trace_unify_fail causes unification to print
  5621 diagnostic information (PG: in trace buffer) when it fails. This is
  5622 useful for figuring out why single step proofs like rule, erule or
  5623 assumption failed.
  5624 
  5625 * Pure: Locale specifications now produce predicate definitions
  5626 according to the body of text (covering assumptions modulo local
  5627 definitions); predicate "loc_axioms" covers newly introduced text,
  5628 while "loc" is cumulative wrt. all included locale expressions; the
  5629 latter view is presented only on export into the global theory
  5630 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5631 on the old view without predicates;
  5632 
  5633 * Pure: predefined locales "var" and "struct" are useful for sharing
  5634 parameters (as in CASL, for example); just specify something like
  5635 ``var x + var y + struct M'' as import;
  5636 
  5637 * Pure: improved thms_containing: proper indexing of facts instead of
  5638 raw theorems; check validity of results wrt. current name space;
  5639 include local facts of proof configuration (also covers active
  5640 locales), cover fixed variables in index; may use "_" in term
  5641 specification; an optional limit for the number of printed facts may
  5642 be given (the default is 40);
  5643 
  5644 * Pure: disallow duplicate fact bindings within new-style theory files
  5645 (batch-mode only);
  5646 
  5647 * Provers: improved induct method: assumptions introduced by case
  5648 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5649 the goal statement); "foo" still refers to all facts collectively;
  5650 
  5651 * Provers: the function blast.overloaded has been removed: all constants
  5652 are regarded as potentially overloaded, which improves robustness in exchange
  5653 for slight decrease in efficiency;
  5654 
  5655 * Provers/linorder: New generic prover for transitivity reasoning over
  5656 linear orders.  Note: this prover is not efficient!
  5657 
  5658 * Isar: preview of problems to finish 'show' now produce an error
  5659 rather than just a warning (in interactive mode);
  5660 
  5661 
  5662 *** HOL ***
  5663 
  5664 * arith(_tac)
  5665 
  5666  - Produces a counter example if it cannot prove a goal.
  5667    Note that the counter example may be spurious if the goal is not a formula
  5668    of quantifier-free linear arithmetic.
  5669    In ProofGeneral the counter example appears in the trace buffer.
  5670 
  5671  - Knows about div k and mod k where k is a numeral of type nat or int.
  5672 
  5673  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5674    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5675    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5676 
  5677 * simp's arithmetic capabilities have been enhanced a bit: it now
  5678 takes ~= in premises into account (by performing a case split);
  5679 
  5680 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5681 are distributed over a sum of terms;
  5682 
  5683 * New tactic "trans_tac" and method "trans" instantiate
  5684 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5685 "<=", "<" and "=").
  5686 
  5687 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5688 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5689 
  5690 * 'typedef' command has new option "open" to suppress the set
  5691 definition;
  5692 
  5693 * functions Min and Max on finite sets have been introduced (theory
  5694 Finite_Set);
  5695 
  5696 * attribute [symmetric] now works for relations as well; it turns
  5697 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5698 
  5699 * induct over a !!-quantified statement (say !!x1..xn):
  5700   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5701 
  5702 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5703 %x. None. Warning: empty_def now refers to the previously hidden definition
  5704 of the empty set.
  5705 
  5706 * Algebra: formalization of classical algebra.  Intended as base for
  5707 any algebraic development in Isabelle.  Currently covers group theory
  5708 (up to Sylow's theorem) and ring theory (Universal Property of
  5709 Univariate Polynomials).  Contributions welcome;
  5710 
  5711 * GroupTheory: deleted, since its material has been moved to Algebra;
  5712 
  5713 * Complex: new directory of the complex numbers with numeric constants,
  5714 nonstandard complex numbers, and some complex analysis, standard and
  5715 nonstandard (Jacques Fleuriot);
  5716 
  5717 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5718 
  5719 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5720 Fleuriot);
  5721 
  5722 * Real/HahnBanach: updated and adapted to locales;
  5723 
  5724 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5725 Gray and Kramer);
  5726 
  5727 * UNITY: added the Meier-Sanders theory of progress sets;
  5728 
  5729 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5730 as abstract algorithms, instantiated to the JVM;
  5731 
  5732 * Bali: Java source language formalization. Type system, operational
  5733 semantics, axiomatic semantics. Supported language features:
  5734 classes, interfaces, objects,virtual methods, static methods,
  5735 static/instance fields, arrays, access modifiers, definite
  5736 assignment, exceptions.
  5737 
  5738 
  5739 *** ZF ***
  5740 
  5741 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5742 universe, etc.);
  5743 
  5744 * Main ZF: virtually all theories converted to new-style format;
  5745 
  5746 
  5747 *** ML ***
  5748 
  5749 * Pure: Tactic.prove provides sane interface for internal proofs;
  5750 omits the infamous "standard" operation, so this is more appropriate
  5751 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5752 
  5753 * Pure: improved error reporting of simprocs;
  5754 
  5755 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5756 up simprocs;
  5757 
  5758 
  5759 *** Document preparation ***
  5760 
  5761 * uses \par instead of \\ for line breaks in theory text. This may
  5762 shift some page breaks in large documents. To get the old behaviour
  5763 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5764 
  5765 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5766 other packages
  5767 
  5768 * \<euro> now needs package babel/greek instead of marvosym (which
  5769 broke \Rightarrow)
  5770 
  5771 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5772 textcomp package)
  5773 
  5774 
  5775 
  5776 New in Isabelle2002 (March 2002)
  5777 --------------------------------
  5778 
  5779 *** Document preparation ***
  5780 
  5781 * greatly simplified document preparation setup, including more
  5782 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5783 instructive isatool mkdir; users should basically be able to get
  5784 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5785 users may run a separate document processing stage manually like this:
  5786 "isatool usedir -D output HOL Test && isatool document Test/output";
  5787 
  5788 * theory dependency graph may now be incorporated into documents;
  5789 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5790 with \includegraphics of LaTeX;
  5791 
  5792 * proper spacing of consecutive markup elements, especially text
  5793 blocks after section headings;
  5794 
  5795 * support bold style (for single symbols only), input syntax is like
  5796 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5797 
  5798 * \<bullet> is now output as bold \cdot by default, which looks much
  5799 better in printed text;
  5800 
  5801 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5802 note that these symbols are currently unavailable in Proof General /
  5803 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5804 
  5805 * isatool latex no longer depends on changed TEXINPUTS, instead
  5806 isatool document copies the Isabelle style files to the target
  5807 location;
  5808 
  5809 
  5810 *** Isar ***
  5811 
  5812 * Pure/Provers: improved proof by cases and induction;
  5813   - 'case' command admits impromptu naming of parameters (such as
  5814     "case (Suc n)");
  5815   - 'induct' method divinates rule instantiation from the inductive
  5816     claim; no longer requires excessive ?P bindings for proper
  5817     instantiation of cases;
  5818   - 'induct' method properly enumerates all possibilities of set/type
  5819     rules; as a consequence facts may be also passed through *type*
  5820     rules without further ado;
  5821   - 'induct' method now derives symbolic cases from the *rulified*
  5822     rule (before it used to rulify cases stemming from the internal
  5823     atomized version); this means that the context of a non-atomic
  5824     statement becomes is included in the hypothesis, avoiding the
  5825     slightly cumbersome show "PROP ?case" form;
  5826   - 'induct' may now use elim-style induction rules without chaining
  5827     facts, using ``missing'' premises from the goal state; this allows
  5828     rules stemming from inductive sets to be applied in unstructured
  5829     scripts, while still benefitting from proper handling of non-atomic
  5830     statements; NB: major inductive premises need to be put first, all
  5831     the rest of the goal is passed through the induction;
  5832   - 'induct' proper support for mutual induction involving non-atomic
  5833     rule statements (uses the new concept of simultaneous goals, see
  5834     below);
  5835   - append all possible rule selections, but only use the first
  5836     success (no backtracking);
  5837   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5838   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5839   - added 'print_induct_rules' (covered by help item in recent Proof
  5840     General versions);
  5841   - moved induct/cases attributes to Pure, methods to Provers;
  5842   - generic method setup instantiated for FOL and HOL;
  5843 
  5844 * Pure: support multiple simultaneous goal statements, for example
  5845 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5846 meta-level mechanism, this acts as if several individual goals had
  5847 been stated separately; in particular common proof methods need to be
  5848 repeated in order to cover all claims; note that a single elimination
  5849 step is *not* sufficient to establish the two conjunctions, so this
  5850 fails:
  5851 
  5852   assume "A & B" then have A and B ..   (*".." fails*)
  5853 
  5854 better use "obtain" in situations as above; alternative refer to
  5855 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5856 
  5857 * Pure: proper integration with ``locales''; unlike the original
  5858 version by Florian Kammller, Isar locales package high-level proof
  5859 contexts rather than raw logical ones (e.g. we admit to include
  5860 attributes everywhere); operations on locales include merge and
  5861 rename; support for implicit arguments (``structures''); simultaneous
  5862 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5863 some examples;
  5864 
  5865 * Pure: the following commands have been ``localized'', supporting a
  5866 target locale specification "(in name)": 'lemma', 'theorem',
  5867 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5868 stored both within the locale and at the theory level (exported and
  5869 qualified by the locale name);
  5870 
  5871 * Pure: theory goals may now be specified in ``long'' form, with
  5872 ad-hoc contexts consisting of arbitrary locale elements. for example
  5873 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5874 definitions may be given, too); the result is a meta-level rule with
  5875 the context elements being discharged in the obvious way;
  5876 
  5877 * Pure: new proof command 'using' allows to augment currently used
  5878 facts after a goal statement ('using' is syntactically analogous to
  5879 'apply', but acts on the goal's facts only); this allows chained facts
  5880 to be separated into parts given before and after a claim, as in
  5881 ``from a and b have C using d and e <proof>'';
  5882 
  5883 * Pure: renamed "antecedent" case to "rule_context";
  5884 
  5885 * Pure: new 'judgment' command records explicit information about the
  5886 object-logic embedding (used by several tools internally); no longer
  5887 use hard-wired "Trueprop";
  5888 
  5889 * Pure: added 'corollary' command;
  5890 
  5891 * Pure: fixed 'token_translation' command;
  5892 
  5893 * Pure: removed obsolete 'exported' attribute;
  5894 
  5895 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5896 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5897 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5898 
  5899 * Pure: method 'atomize' presents local goal premises as object-level
  5900 statements (atomic meta-level propositions); setup controlled via
  5901 rewrite rules declarations of 'atomize' attribute; example
  5902 application: 'induct' method with proper rule statements in improper
  5903 proof *scripts*;
  5904 
  5905 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5906 now consider the syntactic context of assumptions, giving a better
  5907 chance to get type-inference of the arguments right (this is
  5908 especially important for locales);
  5909 
  5910 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5911 mode;
  5912 
  5913 * Pure/obtain: the formal conclusion "thesis", being marked as
  5914 ``internal'', may no longer be reference directly in the text;
  5915 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5916 situations;
  5917 
  5918 * Pure: generic 'sym' attribute which declares a rule both as pure
  5919 'elim?' and for the 'symmetric' operation;
  5920 
  5921 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5922 text; the fixed correlation with particular command syntax has been
  5923 discontinued;
  5924 
  5925 * Pure: new method 'rules' is particularly well-suited for proof
  5926 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5927 but often produces more compact proof terms with less detours;
  5928 
  5929 * Pure/Provers/classical: simplified integration with pure rule
  5930 attributes and methods; the classical "intro?/elim?/dest?"
  5931 declarations coincide with the pure ones; the "rule" method no longer
  5932 includes classically swapped intros; "intro" and "elim" methods no
  5933 longer pick rules from the context; also got rid of ML declarations
  5934 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5935 INCOMPATIBILITY;
  5936 
  5937 * Provers/classical: attribute 'swapped' produces classical inversions
  5938 of introduction rules;
  5939 
  5940 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5941 rules instead of full simplifier context; 'iff' attribute handles
  5942 conditional rules;
  5943 
  5944 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5945 
  5946 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5947 "(permissive)" option to recover old behavior;
  5948 
  5949 * HOL: 'inductive' no longer features separate (collective) attributes
  5950 for 'intros' (was found too confusing);
  5951 
  5952 * HOL: properly declared induction rules less_induct and
  5953 wf_induct_rule;
  5954 
  5955 
  5956 *** HOL ***
  5957 
  5958 * HOL: moved over to sane numeral syntax; the new policy is as
  5959 follows:
  5960 
  5961   - 0 and 1 are polymorphic constants, which are defined on any
  5962   numeric type (nat, int, real etc.);
  5963 
  5964   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5965   binary representation internally;
  5966 
  5967   - type nat has special constructor Suc, and generally prefers Suc 0
  5968   over 1::nat and Suc (Suc 0) over 2::nat;
  5969 
  5970 This change may cause significant problems of INCOMPATIBILITY; here
  5971 are some hints on converting existing sources:
  5972 
  5973   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5974   entities, so expressions involving "-" (unary or binary minus) need
  5975   to be spaced properly;
  5976 
  5977   - existing occurrences of "1" may need to be constraint "1::nat" or
  5978   even replaced by Suc 0; similar for old "2";
  5979 
  5980   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5981 
  5982   - remove all special provisions on numerals in proofs;
  5983 
  5984 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5985 representation (depends on bin_arith_simps in the default context);
  5986 
  5987 * HOL: symbolic syntax for x^2 (numeral 2);
  5988 
  5989 * HOL: the class of all HOL types is now called "type" rather than
  5990 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5991 in axclass/classes, instance/arities, and (usually rare) occurrences
  5992 in typings (of consts etc.); internally the class is called
  5993 "HOL.type", ML programs should refer to HOLogic.typeS;
  5994 
  5995 * HOL/record package improvements:
  5996   - new derived operations "fields" to build a partial record section,
  5997     "extend" to promote a fixed record to a record scheme, and
  5998     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5999     declared as simp by default;
  6000   - shared operations ("more", "fields", etc.) now need to be always
  6001     qualified) --- potential INCOMPATIBILITY;
  6002   - removed "make_scheme" operations (use "make" with "extend") --
  6003     INCOMPATIBILITY;
  6004   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6005   - provides cases/induct rules for use with corresponding Isar
  6006     methods (for concrete records, record schemes, concrete more
  6007     parts, and schematic more parts -- in that order);
  6008   - internal definitions directly based on a light-weight abstract
  6009     theory of product types over typedef rather than datatype;
  6010 
  6011 * HOL: generic code generator for generating executable ML code from
  6012 specifications; specific support for HOL constructs such as inductive
  6013 datatypes and sets, as well as recursive functions; can be invoked
  6014 via 'generate_code' theory section;
  6015 
  6016 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6017 
  6018 * HOL: consolidated and renamed several theories.  In particular:
  6019         Ord.thy has been absorbed into HOL.thy
  6020         String.thy has been absorbed into List.thy
  6021 
  6022 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6023 (beware of argument permutation!);
  6024 
  6025 * HOL: linorder_less_split superseded by linorder_cases;
  6026 
  6027 * HOL/List: "nodups" renamed to "distinct";
  6028 
  6029 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6030 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6031   - Ex_def has changed, now need to use some_eq_ex
  6032 
  6033 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6034 in this (rare) case use:
  6035 
  6036   delSWrapper "split_all_tac"
  6037   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6038 
  6039 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6040 MAY FAIL;
  6041 
  6042 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6043 Isabelle's type classes, ^ on functions and relations has too general
  6044 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6045 necessary to attach explicit type constraints;
  6046 
  6047 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6048 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6049 renamed accordingly (eg "compI" -> "rel_compI").
  6050 
  6051 * HOL: syntax translations now work properly with numerals and records
  6052 expressions;
  6053 
  6054 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6055 of "lam" -- INCOMPATIBILITY;
  6056 
  6057 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6058 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6059 renamed "Product_Type.unit";
  6060 
  6061 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6062 
  6063 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6064 the "cases" method);
  6065 
  6066 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6067 Florian Kammller);
  6068 
  6069 * HOL/IMP: updated and converted to new-style theory format; several
  6070 parts turned into readable document, with proper Isar proof texts and
  6071 some explanations (by Gerwin Klein);
  6072 
  6073 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6074 
  6075 * HOL-Hyperreal is now a logic image;
  6076 
  6077 
  6078 *** HOLCF ***
  6079 
  6080 * Isar: consts/constdefs supports mixfix syntax for continuous
  6081 operations;
  6082 
  6083 * Isar: domain package adapted to new-style theory format, e.g. see
  6084 HOLCF/ex/Dnat.thy;
  6085 
  6086 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6087 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6088 lift.induct_tac, always use UU instead of Undef;
  6089 
  6090 * HOLCF/IMP: updated and converted to new-style theory;
  6091 
  6092 
  6093 *** ZF ***
  6094 
  6095 * Isar: proper integration of logic-specific tools and packages,
  6096 including theory commands '(co)inductive', '(co)datatype',
  6097 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6098 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6099 
  6100 * theory Main no longer includes AC; for the Axiom of Choice, base
  6101 your theory on Main_ZFC;
  6102 
  6103 * the integer library now covers quotients and remainders, with many
  6104 laws relating division to addition, multiplication, etc.;
  6105 
  6106 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6107 typeless version of the formalism;
  6108 
  6109 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6110 format;
  6111 
  6112 * ZF/Induct: new directory for examples of inductive definitions,
  6113 including theory Multiset for multiset orderings; converted to
  6114 new-style theory format;
  6115 
  6116 * ZF: many new theorems about lists, ordinals, etc.;
  6117 
  6118 
  6119 *** General ***
  6120 
  6121 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6122 variable proof controls level of detail: 0 = no proofs (only oracle
  6123 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6124 also ref manual for further ML interfaces;
  6125 
  6126 * Pure/axclass: removed obsolete ML interface
  6127 goal_subclass/goal_arity;
  6128 
  6129 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6130 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6131 separate tokens, so expressions involving minus need to be spaced
  6132 properly;
  6133 
  6134 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6135 rather than "infixl" or "infixr";
  6136 
  6137 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6138 sort constraint specifications in type inference; e.g. "x::_::foo"
  6139 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6140 type variable);
  6141 
  6142 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6143 control output of nested => (types); the default behavior is
  6144 "type_brackets";
  6145 
  6146 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6147 tokens into AST constants;
  6148 
  6149 * Pure/syntax: prefer later declarations of translations and print
  6150 translation functions; potential INCOMPATIBILITY: need to reverse
  6151 multiple declarations for same syntax element constant;
  6152 
  6153 * Pure/show_hyps reset by default (in accordance to existing Isar
  6154 practice);
  6155 
  6156 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6157 addSafter;
  6158 
  6159 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6160 as well;
  6161 
  6162 * system: tested support for MacOS X; should be able to get Isabelle +
  6163 Proof General to work in a plain Terminal after installing Poly/ML
  6164 (e.g. from the Isabelle distribution area) and GNU bash alone
  6165 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6166 support requires further installations, e.g. from
  6167 http://fink.sourceforge.net/);
  6168 
  6169 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6170 
  6171 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6172 of 40 MB), cf. ML_OPTIONS;
  6173 
  6174 * system: Proof General keywords specification is now part of the
  6175 Isabelle distribution (see etc/isar-keywords.el);
  6176 
  6177 * system: support for persistent Proof General sessions (refrain from
  6178 outdating all loaded theories on startup); user may create writable
  6179 logic images like this: ``isabelle -q HOL Test'';
  6180 
  6181 * system: smart selection of Isabelle process versus Isabelle
  6182 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6183 run both "isabelle" and "Isabelle" even if file names are badly
  6184 damaged (executable inspects the case of the first letter of its own
  6185 name); added separate "isabelle-process" and "isabelle-interface";
  6186 
  6187 * system: refrain from any attempt at filtering input streams; no
  6188 longer support ``8bit'' encoding of old isabelle font, instead proper
  6189 iso-latin characters may now be used; the related isatools
  6190 "symbolinput" and "nonascii" have disappeared as well;
  6191 
  6192 * system: removed old "xterm" interface (the print modes "xterm" and
  6193 "xterm_color" are still available for direct use in a suitable
  6194 terminal);
  6195 
  6196 
  6197 
  6198 New in Isabelle99-2 (February 2001)
  6199 -----------------------------------
  6200 
  6201 *** Overview of INCOMPATIBILITIES ***
  6202 
  6203 * HOL: please note that theories in the Library and elsewhere often use the
  6204 new-style (Isar) format; to refer to their theorems in an ML script you must
  6205 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6206 
  6207 * HOL: inductive package no longer splits induction rule aggressively,
  6208 but only as far as specified by the introductions given; the old
  6209 format may be recovered via ML function complete_split_rule or attribute
  6210 'split_rule (complete)';
  6211 
  6212 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6213 gfp_Tarski to gfp_unfold;
  6214 
  6215 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6216 
  6217 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6218 relation); infix "^^" has been renamed "``"; infix "``" has been
  6219 renamed "`"; "univalent" has been renamed "single_valued";
  6220 
  6221 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6222 operation;
  6223 
  6224 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6225 
  6226 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6227 
  6228 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6229 consequence, it is no longer monotonic wrt. the local goal context
  6230 (which is now passed through the inductive cases);
  6231 
  6232 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6233 \<gg> to \<ggreater>;
  6234 
  6235 
  6236 *** Document preparation ***
  6237 
  6238 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6239 available: are "it" for near math-mode best-style output, "sl" for
  6240 slanted text style, and "tt" for plain type-writer; if no
  6241 \isabellestyle command is given, output is according to slanted
  6242 type-writer);
  6243 
  6244 * support sub/super scripts (for single symbols only), input syntax is
  6245 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6246 
  6247 * some more standard symbols; see Appendix A of the system manual for
  6248 the complete list of symbols defined in isabellesym.sty;
  6249 
  6250 * improved isabelle style files; more abstract symbol implementation
  6251 (should now use \isamath{...} and \isatext{...} in custom symbol
  6252 definitions);
  6253 
  6254 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6255 state; Note that presentation of goal states does not conform to
  6256 actual human-readable proof documents.  Please do not include goal
  6257 states into document output unless you really know what you are doing!
  6258 
  6259 * proper indentation of antiquoted output with proportional LaTeX
  6260 fonts;
  6261 
  6262 * no_document ML operator temporarily disables LaTeX document
  6263 generation;
  6264 
  6265 * isatool unsymbolize tunes sources for plain ASCII communication;
  6266 
  6267 
  6268 *** Isar ***
  6269 
  6270 * Pure: Isar now suffers initial goal statements to contain unbound
  6271 schematic variables (this does not conform to actual readable proof
  6272 documents, due to unpredictable outcome and non-compositional proof
  6273 checking); users who know what they are doing may use schematic goals
  6274 for Prolog-style synthesis of proven results;
  6275 
  6276 * Pure: assumption method (an implicit finishing) now handles actual
  6277 rules as well;
  6278 
  6279 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6280 initial goal, declare "that" only as Pure intro (only for single
  6281 steps); the "that" rule assumption may now be involved in implicit
  6282 finishing, thus ".." becomes a feasible for trivial obtains;
  6283 
  6284 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6285 instance proofs may be performed by "..";
  6286 
  6287 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6288 statements as well;
  6289 
  6290 * Pure: more robust selection of calculational rules;
  6291 
  6292 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6293 rule (as well as the assumption rule);
  6294 
  6295 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6296 lemmas, using the graph browser tool;
  6297 
  6298 * Pure: predict failure of "show" in interactive mode;
  6299 
  6300 * Pure: 'thms_containing' now takes actual terms as arguments;
  6301 
  6302 * HOL: improved method 'induct' --- now handles non-atomic goals
  6303 (potential INCOMPATIBILITY); tuned error handling;
  6304 
  6305 * HOL: cases and induct rules now provide explicit hints about the
  6306 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6307 any remaining facts are inserted into the goal verbatim;
  6308 
  6309 * HOL: local contexts (aka cases) may now contain term bindings as
  6310 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6311 the result to be shown in each case;
  6312 
  6313 * HOL: added 'recdef_tc' command;
  6314 
  6315 * isatool convert assists in eliminating legacy ML scripts;
  6316 
  6317 
  6318 *** HOL ***
  6319 
  6320 * HOL/Library: a collection of generic theories to be used together
  6321 with main HOL; the theory loader path already includes this directory
  6322 by default; the following existing theories have been moved here:
  6323 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6324 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6325 
  6326 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6327 modelling and verification task performed in Isabelle/HOL +
  6328 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6329 
  6330 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6331 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6332 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6333 'domain', this makes the theory consistent with mathematical
  6334 literature;
  6335 
  6336 * HOL basics: added overloaded operations "inverse" and "divide"
  6337 (infix "/"), syntax for generic "abs" operation, generic summation
  6338 operator \<Sum>;
  6339 
  6340 * HOL/typedef: simplified package, provide more useful rules (see also
  6341 HOL/subset.thy);
  6342 
  6343 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6344 now expressed as a proper nested rule (old-style tactic scripts may
  6345 require atomize_strip_tac to cope with non-atomic premises);
  6346 
  6347 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6348 to "split_conv" (old name still available for compatibility);
  6349 
  6350 * HOL: improved concrete syntax for strings (e.g. allows translation
  6351 rules with string literals);
  6352 
  6353 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6354  and Fleuriot's mechanization of analysis, including the transcendental
  6355  functions for the reals;
  6356 
  6357 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6358 
  6359 
  6360 *** CTT ***
  6361 
  6362 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6363 "lam" is displayed as TWO lambda-symbols
  6364 
  6365 * CTT: theory Main now available, containing everything (that is, Bool
  6366 and Arith);
  6367 
  6368 
  6369 *** General ***
  6370 
  6371 * Pure: the Simplifier has been implemented properly as a derived rule
  6372 outside of the actual kernel (at last!); the overall performance
  6373 penalty in practical applications is about 50%, while reliability of
  6374 the Isabelle inference kernel has been greatly improved;
  6375 
  6376 * print modes "brackets" and "no_brackets" control output of nested =>
  6377 (types) and ==> (props); the default behaviour is "brackets";
  6378 
  6379 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6380 as assumptions as well;
  6381 
  6382 * system: support Poly/ML 4.0;
  6383 
  6384 * system: isatool install handles KDE version 1 or 2;
  6385 
  6386 
  6387 
  6388 New in Isabelle99-1 (October 2000)
  6389 ----------------------------------
  6390 
  6391 *** Overview of INCOMPATIBILITIES ***
  6392 
  6393 * HOL: simplification of natural numbers is much changed; to partly
  6394 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6395 issue the following ML commands:
  6396 
  6397   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6398   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6399 
  6400 * HOL: simplification no longer dives into case-expressions; this is
  6401 controlled by "t.weak_case_cong" for each datatype t;
  6402 
  6403 * HOL: nat_less_induct renamed to less_induct;
  6404 
  6405 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6406 fixsome to patch .thy and .ML sources automatically;
  6407 
  6408   select_equality  -> some_equality
  6409   select_eq_Ex     -> some_eq_ex
  6410   selectI2EX       -> someI2_ex
  6411   selectI2         -> someI2
  6412   selectI          -> someI
  6413   select1_equality -> some1_equality
  6414   Eps_sym_eq       -> some_sym_eq_trivial
  6415   Eps_eq           -> some_eq_trivial
  6416 
  6417 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6418 
  6419 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6420 instead);
  6421 
  6422 * HOL: the recursion equations generated by 'recdef' are now called
  6423 f.simps instead of f.rules;
  6424 
  6425 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6426 
  6427 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6428 sometimes be needed;
  6429 
  6430 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6431 
  6432 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6433 
  6434 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6435 product is now "<*>" instead of "Times"; the lexicographic product is
  6436 now "<*lex*>" instead of "**";
  6437 
  6438 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6439 of main HOL, but was unused); better use HOL's datatype package;
  6440 
  6441 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6442 the old syntax may be recovered as follows:
  6443 
  6444   syntax (symbols)
  6445     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6446       (infixl "\\<oplus>" 100)
  6447 
  6448 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6449 
  6450 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6451 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6452 internally;
  6453 
  6454 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6455 changed from A/r to A//r;
  6456 
  6457 * ZF: new treatment of arithmetic (nat & int) may break some old
  6458 proofs;
  6459 
  6460 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6461 rulify -> rule_format, elimify -> elim_format, ...);
  6462 
  6463 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6464 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6465 should have to change intro!! to intro? only); replaced "delrule" by
  6466 "rule del";
  6467 
  6468 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6469 
  6470 * Provers: strengthened force_tac by using new first_best_tac;
  6471 
  6472 * LaTeX document preparation: several changes of isabelle.sty (see
  6473 lib/texinputs);
  6474 
  6475 
  6476 *** Document preparation ***
  6477 
  6478 * formal comments (text blocks etc.) in new-style theories may now
  6479 contain antiquotations of thm/prop/term/typ/text to be presented
  6480 according to latex print mode; concrete syntax is like this:
  6481 @{term[show_types] "f(x) = a + x"};
  6482 
  6483 * isatool mkdir provides easy setup of Isabelle session directories,
  6484 including proper document sources;
  6485 
  6486 * generated LaTeX sources are now deleted after successful run
  6487 (isatool document -c); may retain a copy somewhere else via -D option
  6488 of isatool usedir;
  6489 
  6490 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6491 style files, achieving self-contained LaTeX sources and simplifying
  6492 LaTeX debugging;
  6493 
  6494 * old-style theories now produce (crude) LaTeX output as well;
  6495 
  6496 * browser info session directories are now self-contained (may be put
  6497 on WWW server seperately); improved graphs of nested sessions; removed
  6498 graph for 'all sessions';
  6499 
  6500 * several improvements in isabelle style files; \isabellestyle{it}
  6501 produces fake math mode output; \isamarkupheader is now \section by
  6502 default; see lib/texinputs/isabelle.sty etc.;
  6503 
  6504 
  6505 *** Isar ***
  6506 
  6507 * Isar/Pure: local results and corresponding term bindings are now
  6508 subject to Hindley-Milner polymorphism (similar to ML); this
  6509 accommodates incremental type-inference very nicely;
  6510 
  6511 * Isar/Pure: new derived language element 'obtain' supports
  6512 generalized existence reasoning;
  6513 
  6514 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6515 support accumulation of results, without applying any rules yet;
  6516 useful to collect intermediate results without explicit name
  6517 references, and for use with transitivity rules with more than 2
  6518 premises;
  6519 
  6520 * Isar/Pure: scalable support for case-analysis type proofs: new
  6521 'case' language element refers to local contexts symbolically, as
  6522 produced by certain proof methods; internally, case names are attached
  6523 to theorems as "tags";
  6524 
  6525 * Isar/Pure: theory command 'hide' removes declarations from
  6526 class/type/const name spaces;
  6527 
  6528 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6529 indicate potential overloading;
  6530 
  6531 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6532 
  6533 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6534 "{a,b,c}" instead of {a,b,c};
  6535 
  6536 * Isar/Pure now provides its own version of intro/elim/dest
  6537 attributes; useful for building new logics, but beware of confusion
  6538 with the version in Provers/classical;
  6539 
  6540 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6541 case name 'antecedent';
  6542 
  6543 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6544 to the current context is now done automatically);
  6545 
  6546 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6547 for definining proof methods in ML;
  6548 
  6549 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6550 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6551 most cases, one should have to change intro!! to intro? only);
  6552 replaced "delrule" by "rule del";
  6553 
  6554 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6555 'symmetric' attribute (the latter supercedes [RS sym]);
  6556 
  6557 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6558 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6559 well (including splits);
  6560 
  6561 * Isar/Provers: Simplifier and Classical methods now support all kind
  6562 of modifiers used in the past, including 'cong', 'iff', etc.
  6563 
  6564 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6565 of Simplifier and Classical reasoner);
  6566 
  6567 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6568 now support named cases; major packages (inductive, datatype, primrec,
  6569 recdef) support case names and properly name parameters;
  6570 
  6571 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6572 monotonicity conditions are extracted to be proven at end of
  6573 calculations;
  6574 
  6575 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6576 method anyway;
  6577 
  6578 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6579 split_if split_if_asm; datatype package provides theorems foo.splits =
  6580 foo.split foo.split_asm for each datatype;
  6581 
  6582 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6583 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6584 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6585 use "(cases (simplified))" method in proper proof texts);
  6586 
  6587 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6588 
  6589 * Isar: names of theorems etc. may be natural numbers as well;
  6590 
  6591 * Isar: 'pr' command: optional arguments for goals_limit and
  6592 ProofContext.prems_limit; no longer prints theory contexts, but only
  6593 proof states;
  6594 
  6595 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6596 additional print modes to be specified; e.g. "pr(latex)" will print
  6597 proof state according to the Isabelle LaTeX style;
  6598 
  6599 * Isar: improved support for emulating tactic scripts, including proof
  6600 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6601 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6602 (for HOL datatypes);
  6603 
  6604 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6605 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6606 'proof method scripts' have to be in depth-first order;
  6607 
  6608 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6609 
  6610 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6611 should instead use individual commands for printing items
  6612 (print_commands, print_methods etc.);
  6613 
  6614 * Isar: added 'nothing' --- the empty list of theorems;
  6615 
  6616 
  6617 *** HOL ***
  6618 
  6619 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6620 corresponding virtual machine and a specification of its bytecode
  6621 verifier and a lightweight bytecode verifier, including proofs of
  6622 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6623 Cornelia Pusch (see also the homepage of project Bali at
  6624 http://isabelle.in.tum.de/Bali/);
  6625 
  6626 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6627 Clemens Ballarin;
  6628 
  6629 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6630 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6631 Rasmussen;
  6632 
  6633 * HOL/Lattice: fundamental concepts of lattice theory and order
  6634 structures, including duals, properties of bounds versus algebraic
  6635 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6636 Theorem for complete lattices etc.; may also serve as a demonstration
  6637 for abstract algebraic reasoning using axiomatic type classes, and
  6638 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6639 
  6640 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6641 von Oheimb;
  6642 
  6643 * HOL/IMPP: extension of IMP with local variables and mutually
  6644 recursive procedures, by David von Oheimb;
  6645 
  6646 * HOL/Lambda: converted into new-style theory and document;
  6647 
  6648 * HOL/ex/Multiquote: example of multiple nested quotations and
  6649 anti-quotations -- basically a generalized version of de-Bruijn
  6650 representation; very useful in avoiding lifting of operations;
  6651 
  6652 * HOL/record: added general record equality rule to simpset; fixed
  6653 select-update simplification procedure to handle extended records as
  6654 well; admit "r" as field name;
  6655 
  6656 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6657 other numeric types and also as the identity of groups, rings, etc.;
  6658 
  6659 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6660 Types nat and int belong to this axclass;
  6661 
  6662 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6663    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6664    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6665   two terms #m*u and #n*u are replaced by #(m+n)*u
  6666     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6667   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6668     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6669 
  6670 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6671 powerful prover for predicate logic but knows nothing of clasets; see
  6672 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6673 
  6674 * HOL: new version of "case_tac" subsumes both boolean case split and
  6675 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6676 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6677 
  6678 * HOL: simplification no longer dives into case-expressions: only the
  6679 selector expression is simplified, but not the remaining arms; to
  6680 enable full simplification of case-expressions for datatype t, you may
  6681 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6682 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6683 
  6684 * HOL/recdef: the recursion equations generated by 'recdef' for
  6685 function 'f' are now called f.simps instead of f.rules; if all
  6686 termination conditions are proved automatically, these simplification
  6687 rules are added to the simpset, as in primrec; rules may be named
  6688 individually as well, resulting in a separate list of theorems for
  6689 each equation;
  6690 
  6691 * HOL/While is a new theory that provides a while-combinator. It
  6692 permits the definition of tail-recursive functions without the
  6693 provision of a termination measure. The latter is necessary once the
  6694 invariant proof rule for while is applied.
  6695 
  6696 * HOL: new (overloaded) notation for the set of elements below/above
  6697 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6698 
  6699 * HOL: theorems impI, allI, ballI bound as "strip";
  6700 
  6701 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6702 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6703 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6704 
  6705 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6706 
  6707 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6708 main HOL, but was unused);
  6709 
  6710 * HOL: fewer consts declared as global (e.g. have to refer to
  6711 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6712 
  6713 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6714 in case of overlap with user translations (e.g. judgements over
  6715 tuples); (note that the underlying logical represenation is still
  6716 bogus);
  6717 
  6718 
  6719 *** ZF ***
  6720 
  6721 * ZF: simplification automatically cancels common terms in arithmetic
  6722 expressions over nat and int;
  6723 
  6724 * ZF: new treatment of nat to minimize type-checking: all operators
  6725 coerce their operands to a natural number using the function natify,
  6726 making the algebraic laws unconditional;
  6727 
  6728 * ZF: as above, for int: operators coerce their operands to an integer
  6729 using the function intify;
  6730 
  6731 * ZF: the integer library now contains many of the usual laws for the
  6732 orderings, including $<=, and monotonicity laws for $+ and $*;
  6733 
  6734 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6735 simplification;
  6736 
  6737 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6738 to the simplifier and classical reasoner simultaneously;
  6739 
  6740 
  6741 *** General ***
  6742 
  6743 * Provers: blast_tac now handles actual object-logic rules as
  6744 assumptions; note that auto_tac uses blast_tac internally as well;
  6745 
  6746 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6747 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6748 
  6749 * Provers: delrules now handles destruct rules as well (no longer need
  6750 explicit make_elim);
  6751 
  6752 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6753   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6754 use instead the strong form,
  6755   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6756 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6757 from destruct-rules;
  6758 
  6759 * Provers: Simplifier.easy_setup provides a fast path to basic
  6760 Simplifier setup for new object-logics;
  6761 
  6762 * Pure: AST translation rules no longer require constant head on LHS;
  6763 
  6764 * Pure: improved name spaces: ambiguous output is qualified; support
  6765 for hiding of names;
  6766 
  6767 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6768 XSYMBOL_HOME; no longer need to do manual configuration in most
  6769 situations;
  6770 
  6771 * system: compression of ML heaps images may now be controlled via -c
  6772 option of isabelle and isatool usedir (currently only observed by
  6773 Poly/ML);
  6774 
  6775 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6776 useful for remote X11);
  6777 
  6778 * system: provide TAGS file for Isabelle sources;
  6779 
  6780 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6781 order;
  6782 
  6783 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6784 timing flag supersedes proof_timing and Toplevel.trace;
  6785 
  6786 * ML: new combinators |>> and |>>> for incremental transformations
  6787 with secondary results (e.g. certain theory extensions):
  6788 
  6789 * ML: PureThy.add_defs gets additional argument to indicate potential
  6790 overloading (usually false);
  6791 
  6792 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6793 results;
  6794 
  6795 
  6796 
  6797 New in Isabelle99 (October 1999)
  6798 --------------------------------
  6799 
  6800 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6801 
  6802 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6803 are no longer simplified.  (This allows the simplifier to unfold recursive
  6804 functional programs.)  To restore the old behaviour, declare
  6805 
  6806     Delcongs [if_weak_cong];
  6807 
  6808 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6809 complement;
  6810 
  6811 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6812 
  6813 * HOL/datatype: mutual_induct_tac no longer exists --
  6814   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6815 
  6816 * HOL/typedef: fixed type inference for representing set; type
  6817 arguments now have to occur explicitly on the rhs as type constraints;
  6818 
  6819 * ZF: The con_defs part of an inductive definition may no longer refer
  6820 to constants declared in the same theory;
  6821 
  6822 * HOL, ZF: the function mk_cases, generated by the inductive
  6823 definition package, has lost an argument.  To simplify its result, it
  6824 uses the default simpset instead of a supplied list of theorems.
  6825 
  6826 * HOL/List: the constructors of type list are now Nil and Cons;
  6827 
  6828 * Simplifier: the type of the infix ML functions
  6829         setSSolver addSSolver setSolver addSolver
  6830 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6831 for packaging solvers. A solver is created via
  6832         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6833 where the string argument is only a comment.
  6834 
  6835 
  6836 *** Proof tools ***
  6837 
  6838 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6839 decision procedure for linear arithmetic. Currently it is used for
  6840 types `nat', `int', and `real' in HOL (see below); it can, should and
  6841 will be instantiated for other types and logics as well.
  6842 
  6843 * The simplifier now accepts rewrite rules with flexible heads, eg
  6844      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6845   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6846   matching.
  6847 
  6848 
  6849 *** General ***
  6850 
  6851 * New Isabelle/Isar subsystem provides an alternative to traditional
  6852 tactical theorem proving; together with the ProofGeneral/isar user
  6853 interface it offers an interactive environment for developing human
  6854 readable proof documents (Isar == Intelligible semi-automated
  6855 reasoning); for further information see isatool doc isar-ref,
  6856 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  6857 
  6858 * improved and simplified presentation of theories: better HTML markup
  6859 (including colors), graph views in several sizes; isatool usedir now
  6860 provides a proper interface for user theories (via -P option); actual
  6861 document preparation based on (PDF)LaTeX is available as well (for
  6862 new-style theories only); see isatool doc system for more information;
  6863 
  6864 * native support for Proof General, both for classic Isabelle and
  6865 Isabelle/Isar;
  6866 
  6867 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  6868 using the graph browser tool;
  6869 
  6870 * Isabelle manuals now also available as PDF;
  6871 
  6872 * theory loader rewritten from scratch (may not be fully
  6873 bug-compatible); old loadpath variable has been replaced by show_path,
  6874 add_path, del_path, reset_path functions; new operations such as
  6875 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  6876 isatool doc ref);
  6877 
  6878 * improved isatool install: option -k creates KDE application icon,
  6879 option -p DIR installs standalone binaries;
  6880 
  6881 * added ML_PLATFORM setting (useful for cross-platform installations);
  6882 more robust handling of platform specific ML images for SML/NJ;
  6883 
  6884 * the settings environment is now statically scoped, i.e. it is never
  6885 created again in sub-processes invoked from isabelle, isatool, or
  6886 Isabelle;
  6887 
  6888 * path element specification '~~' refers to '$ISABELLE_HOME';
  6889 
  6890 * in locales, the "assumes" and "defines" parts may be omitted if
  6891 empty;
  6892 
  6893 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  6894 long arrows);
  6895 
  6896 * new print_mode "HTML";
  6897 
  6898 * new flag show_tags controls display of tags of theorems (which are
  6899 basically just comments that may be attached by some tools);
  6900 
  6901 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  6902 mode and goal output format:
  6903 
  6904 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  6905 244c244
  6906 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  6907 ---
  6908 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  6909 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  6910 181c181
  6911 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  6912 ---
  6913 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  6914 
  6915 * function bind_thms stores lists of theorems (cf. bind_thm);
  6916 
  6917 * new shorthand tactics ftac, eatac, datac, fatac;
  6918 
  6919 * qed (and friends) now accept "" as result name; in that case the
  6920 theorem is not stored, but proper checks and presentation of the
  6921 result still apply;
  6922 
  6923 * theorem database now also indexes constants "Trueprop", "all",
  6924 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  6925 
  6926 
  6927 *** HOL ***
  6928 
  6929 ** HOL arithmetic **
  6930 
  6931 * There are now decision procedures for linear arithmetic over nat and
  6932 int:
  6933 
  6934 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  6935 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  6936 are treated as atomic; subformulae not involving type `nat' or `int'
  6937 are ignored; quantified subformulae are ignored unless they are
  6938 positive universal or negative existential. The tactic has to be
  6939 invoked by hand and can be a little bit slow. In particular, the
  6940 running time is exponential in the number of occurrences of `min' and
  6941 `max', and `-' on `nat'.
  6942 
  6943 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  6944 (negated) (in)equalities among the premises and the conclusion into
  6945 account (i.e. no compound formulae) and does not know about `min' and
  6946 `max', and `-' on `nat'. It is fast and is used automatically by the
  6947 simplifier.
  6948 
  6949 NB: At the moment, these decision procedures do not cope with mixed
  6950 nat/int formulae where the two parts interact, such as `m < n ==>
  6951 int(m) < int(n)'.
  6952 
  6953 * HOL/Numeral provides a generic theory of numerals (encoded
  6954 efficiently as bit strings); setup for types nat/int/real is in place;
  6955 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  6956 int, existing theories and proof scripts may require a few additional
  6957 type constraints;
  6958 
  6959 * integer division and remainder can now be performed on constant
  6960 arguments;
  6961 
  6962 * many properties of integer multiplication, division and remainder
  6963 are now available;
  6964 
  6965 * An interface to the Stanford Validity Checker (SVC) is available through the
  6966 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  6967 are proved automatically.  SVC must be installed separately, and its results
  6968 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  6969 invocation of the underlying oracle).  For SVC see
  6970   http://verify.stanford.edu/SVC
  6971 
  6972 * IsaMakefile: the HOL-Real target now builds an actual image;
  6973 
  6974 
  6975 ** HOL misc **
  6976 
  6977 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  6978 (in Isabelle/Isar) -- by Gertrud Bauer;
  6979 
  6980 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  6981 analysis for assembly languages with subtypes;
  6982 
  6983 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  6984 -- avoids syntactic ambiguities and treats state, transition, and
  6985 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  6986 changed syntax and (many) tactics;
  6987 
  6988 * HOL/inductive: Now also handles more general introduction rules such
  6989   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  6990   theorems are now maintained within the theory (maintained via the
  6991   "mono" attribute);
  6992 
  6993 * HOL/datatype: Now also handles arbitrarily branching datatypes
  6994   (using function types) such as
  6995 
  6996   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  6997 
  6998 * HOL/record: record_simproc (part of the default simpset) takes care
  6999 of selectors applied to updated records; record_split_tac is no longer
  7000 part of the default claset; update_defs may now be removed from the
  7001 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7002 
  7003   claset_ref () := claset() addSWrapper record_split_wrapper;
  7004   Delsimprocs [record_simproc]
  7005 
  7006 * HOL/typedef: fixed type inference for representing set; type
  7007 arguments now have to occur explicitly on the rhs as type constraints;
  7008 
  7009 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7010 names rather than an ML expression;
  7011 
  7012 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7013 supplied later.  Program schemes can be defined, such as
  7014     "While B C s = (if B s then While B C (C s) else s)"
  7015 where the well-founded relation can be chosen after B and C have been given.
  7016 
  7017 * HOL/List: the constructors of type list are now Nil and Cons;
  7018 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7019 course, ML tools referring to List.list.op # etc. have to be adapted;
  7020 
  7021 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7022 disabled by default; run isabelle with option -m HOL to get back to
  7023 the original Gordon/HOL-style output;
  7024 
  7025 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7026 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7027 
  7028 * HOL basic syntax simplified (more orthogonal): all variants of
  7029 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7030 Eps operator is provided as well: "SOME x. P[x]";
  7031 
  7032 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7033 
  7034 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7035 thus available for user theories;
  7036 
  7037 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7038 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7039 time;
  7040 
  7041 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7042 several times and then mp;
  7043 
  7044 
  7045 *** LK ***
  7046 
  7047 * the notation <<...>> is now available as a notation for sequences of
  7048 formulas;
  7049 
  7050 * the simplifier is now installed
  7051 
  7052 * the axiom system has been generalized (thanks to Soren Heilmann)
  7053 
  7054 * the classical reasoner now has a default rule database
  7055 
  7056 
  7057 *** ZF ***
  7058 
  7059 * new primrec section allows primitive recursive functions to be given
  7060 directly (as in HOL) over datatypes and the natural numbers;
  7061 
  7062 * new tactics induct_tac and exhaust_tac for induction (or case
  7063 analysis) over datatypes and the natural numbers;
  7064 
  7065 * the datatype declaration of type T now defines the recursor T_rec;
  7066 
  7067 * simplification automatically does freeness reasoning for datatype
  7068 constructors;
  7069 
  7070 * automatic type-inference, with AddTCs command to insert new
  7071 type-checking rules;
  7072 
  7073 * datatype introduction rules are now added as Safe Introduction rules
  7074 to the claset;
  7075 
  7076 * the syntax "if P then x else y" is now available in addition to
  7077 if(P,x,y);
  7078 
  7079 
  7080 *** Internal programming interfaces ***
  7081 
  7082 * tuned simplifier trace output; new flag debug_simp;
  7083 
  7084 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7085 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7086 
  7087 * AxClass.axclass_tac lost the theory argument;
  7088 
  7089 * tuned current_goals_markers semantics: begin / end goal avoids
  7090 printing empty lines;
  7091 
  7092 * removed prs and prs_fn hook, which was broken because it did not
  7093 include \n in its semantics, forcing writeln to add one
  7094 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7095 string -> unit if you really want to output text without newline;
  7096 
  7097 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7098 plain output, interface builders may have to enable 'isabelle_font'
  7099 mode to get Isabelle font glyphs as before;
  7100 
  7101 * refined token_translation interface; INCOMPATIBILITY: output length
  7102 now of type real instead of int;
  7103 
  7104 * theory loader actions may be traced via new ThyInfo.add_hook
  7105 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7106 your own database of information attached to *whole* theories -- as
  7107 opposed to intra-theory data slots offered via TheoryDataFun;
  7108 
  7109 * proper handling of dangling sort hypotheses (at last!);
  7110 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7111 extra sort hypotheses that can be witnessed from the type signature;
  7112 the force_strip_shyps flag is gone, any remaining shyps are simply
  7113 left in the theorem (with a warning issued by strip_shyps_warning);
  7114 
  7115 
  7116 
  7117 New in Isabelle98-1 (October 1998)
  7118 ----------------------------------
  7119 
  7120 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7121 
  7122 * several changes of automated proof tools;
  7123 
  7124 * HOL: major changes to the inductive and datatype packages, including
  7125 some minor incompatibilities of theory syntax;
  7126 
  7127 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7128 called `inj_on';
  7129 
  7130 * HOL: removed duplicate thms in Arith:
  7131   less_imp_add_less  should be replaced by  trans_less_add1
  7132   le_imp_add_le      should be replaced by  trans_le_add1
  7133 
  7134 * HOL: unary minus is now overloaded (new type constraints may be
  7135 required);
  7136 
  7137 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7138 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7139 now taken as an integer constant.
  7140 
  7141 * Pure: ML function 'theory_of' renamed to 'theory';
  7142 
  7143 
  7144 *** Proof tools ***
  7145 
  7146 * Simplifier:
  7147   1. Asm_full_simp_tac is now more aggressive.
  7148      1. It will sometimes reorient premises if that increases their power to
  7149         simplify.
  7150      2. It does no longer proceed strictly from left to right but may also
  7151         rotate premises to achieve further simplification.
  7152      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7153      old Asm_full_simp_tac in that it does not rotate premises.
  7154   2. The simplifier now knows a little bit about nat-arithmetic.
  7155 
  7156 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7157 allows for selected deletion of wrappers, by introduction of names for
  7158 wrapper functionals.  This implies that addbefore, addSbefore,
  7159 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7160 and that adding two tactics with the same name overwrites the first
  7161 one (emitting a warning).
  7162   type wrapper = (int -> tactic) -> (int -> tactic)
  7163   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7164   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7165   delWrapper, delSWrapper: claset *  string            -> claset
  7166   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7167 
  7168 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7169 semantics; addbefore now affects only the unsafe part of step_tac
  7170 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7171 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7172 by Force_tac;
  7173 
  7174 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7175 compWrapper; added safe wrapper (and access functions for it);
  7176 
  7177 * HOL/split_all_tac is now much faster and fails if there is nothing
  7178 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7179 and the names of the automatically generated variables have changed.
  7180 split_all_tac has moved within claset() from unsafe wrappers to safe
  7181 wrappers, which means that !!-bound variables are split much more
  7182 aggressively, and safe_tac and clarify_tac now split such variables.
  7183 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7184 Note: the same holds for record_split_tac, which does the job of
  7185 split_all_tac for record fields.
  7186 
  7187 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7188 permanently to the default simpset using Addsplits just like
  7189 Addsimps. They can be removed via Delsplits just like
  7190 Delsimps. Lower-case versions are also available.
  7191 
  7192 * HOL/Simplifier: The rule split_if is now part of the default
  7193 simpset. This means that the simplifier will eliminate all occurrences
  7194 of if-then-else in the conclusion of a goal. To prevent this, you can
  7195 either remove split_if completely from the default simpset by
  7196 `Delsplits [split_if]' or remove it in a specific call of the
  7197 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7198 other case splitting rules to/from the default simpset: every datatype
  7199 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7200 t is the name of the datatype).
  7201 
  7202 * Classical reasoner / Simplifier combination: new force_tac (and
  7203 derivatives Force_tac, force) combines rewriting and classical
  7204 reasoning (and whatever other tools) similarly to auto_tac, but is
  7205 aimed to solve the given subgoal completely.
  7206 
  7207 
  7208 *** General ***
  7209 
  7210 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7211 and `goalw': the theory is no longer needed as an explicit argument -
  7212 the current theory context is used; assumptions are no longer returned
  7213 at the ML-level unless one of them starts with ==> or !!; it is
  7214 recommended to convert to these new commands using isatool fixgoal
  7215 (backup your sources first!);
  7216 
  7217 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7218 the current theory context, and 'theory' to lookup stored theories;
  7219 
  7220 * new theory section 'locale' for declaring constants, assumptions and
  7221 definitions that have local scope;
  7222 
  7223 * new theory section 'nonterminals' for purely syntactic types;
  7224 
  7225 * new theory section 'setup' for generic ML setup functions
  7226 (e.g. package initialization);
  7227 
  7228 * the distribution now includes Isabelle icons: see
  7229 lib/logo/isabelle-{small,tiny}.xpm;
  7230 
  7231 * isatool install - install binaries with absolute references to
  7232 ISABELLE_HOME/bin;
  7233 
  7234 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7235 
  7236 * print mode 'emacs' reserved for Isamode;
  7237 
  7238 * support multiple print (ast) translations per constant name;
  7239 
  7240 * theorems involving oracles are now printed with a suffixed [!];
  7241 
  7242 
  7243 *** HOL ***
  7244 
  7245 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7246 
  7247 * HOL/inductive package reorganized and improved: now supports mutual
  7248 definitions such as
  7249 
  7250   inductive EVEN ODD
  7251     intrs
  7252       null "0 : EVEN"
  7253       oddI "n : EVEN ==> Suc n : ODD"
  7254       evenI "n : ODD ==> Suc n : EVEN"
  7255 
  7256 new theorem list "elims" contains an elimination rule for each of the
  7257 recursive sets; inductive definitions now handle disjunctive premises
  7258 correctly (also ZF);
  7259 
  7260 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7261 "mutual_induct" no longer exists - the induction rule is always
  7262 contained in "induct";
  7263 
  7264 
  7265 * HOL/datatype package re-implemented and greatly improved: now
  7266 supports mutually recursive datatypes such as
  7267 
  7268   datatype
  7269     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7270             | SUM ('a aexp) ('a aexp)
  7271             | DIFF ('a aexp) ('a aexp)
  7272             | NUM 'a
  7273   and
  7274     'a bexp = LESS ('a aexp) ('a aexp)
  7275             | AND ('a bexp) ('a bexp)
  7276             | OR ('a bexp) ('a bexp)
  7277 
  7278 as well as indirectly recursive datatypes such as
  7279 
  7280   datatype
  7281     ('a, 'b) term = Var 'a
  7282                   | App 'b ((('a, 'b) term) list)
  7283 
  7284 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7285 induction on mutually / indirectly recursive datatypes.
  7286 
  7287 Primrec equations are now stored in theory and can be accessed via
  7288 <function_name>.simps.
  7289 
  7290 INCOMPATIBILITIES:
  7291 
  7292   - Theories using datatypes must now have theory Datatype as an
  7293     ancestor.
  7294   - The specific <typename>.induct_tac no longer exists - use the
  7295     generic induct_tac instead.
  7296   - natE has been renamed to nat.exhaust - use exhaust_tac
  7297     instead of res_inst_tac ... natE. Note that the variable
  7298     names in nat.exhaust differ from the names in natE, this
  7299     may cause some "fragile" proofs to fail.
  7300   - The theorems split_<typename>_case and split_<typename>_case_asm
  7301     have been renamed to <typename>.split and <typename>.split_asm.
  7302   - Since default sorts of type variables are now handled correctly,
  7303     some datatype definitions may have to be annotated with explicit
  7304     sort constraints.
  7305   - Primrec definitions no longer require function name and type
  7306     of recursive argument.
  7307 
  7308 Consider using isatool fixdatatype to adapt your theories and proof
  7309 scripts to the new package (backup your sources first!).
  7310 
  7311 
  7312 * HOL/record package: considerably improved implementation; now
  7313 includes concrete syntax for record types, terms, updates; theorems
  7314 for surjective pairing and splitting !!-bound record variables; proof
  7315 support is as follows:
  7316 
  7317   1) standard conversions (selectors or updates applied to record
  7318 constructor terms) are part of the standard simpset;
  7319 
  7320   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7321 made part of standard simpset and claset via addIffs;
  7322 
  7323   3) a tactic for record field splitting (record_split_tac) is part of
  7324 the standard claset (addSWrapper);
  7325 
  7326 To get a better idea about these rules you may retrieve them via
  7327 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7328 the name of your record type.
  7329 
  7330 The split tactic 3) conceptually simplifies by the following rule:
  7331 
  7332   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7333 
  7334 Thus any record variable that is bound by meta-all will automatically
  7335 blow up into some record constructor term, consequently the
  7336 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7337 solve record problems automatically.
  7338 
  7339 
  7340 * reorganized the main HOL image: HOL/Integ and String loaded by
  7341 default; theory Main includes everything;
  7342 
  7343 * automatic simplification of integer sums and comparisons, using cancellation;
  7344 
  7345 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7346 
  7347 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7348 
  7349 * many new identities for unions, intersections, set difference, etc.;
  7350 
  7351 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7352 called split_if, split_split, split_sum_case and split_nat_case (to go
  7353 with add/delsplits);
  7354 
  7355 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7356 (?x::unit) = (); this is made part of the default simpset, which COULD
  7357 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7358 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7359 unit_abs_eta_conv is added in order to counter the effect of
  7360 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7361 %u.f();
  7362 
  7363 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7364 makes more sense);
  7365 
  7366 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7367   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7368   disjointness reasoning but breaking a few old proofs.
  7369 
  7370 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7371 to 'converse' from 'inverse' (for compatibility with ZF and some
  7372 literature);
  7373 
  7374 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7375 the well-founded relation;
  7376 
  7377 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7378     Compl A.  The "Compl" syntax remains available as input syntax for this
  7379     release ONLY.
  7380 
  7381 * HOL/Update: new theory of function updates:
  7382     f(a:=b) == %x. if x=a then b else f x
  7383 may also be iterated as in f(a:=b,c:=d,...);
  7384 
  7385 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7386 
  7387 * HOL/List:
  7388   - new function list_update written xs[i:=v] that updates the i-th
  7389     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7390   - new function `upt' written [i..j(] which generates the list
  7391     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7392     bound write [i..j], which is a shorthand for [i..j+1(].
  7393   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7394 
  7395 * HOL/Arith:
  7396   - removed 'pred' (predecessor) function;
  7397   - generalized some theorems about n-1;
  7398   - many new laws about "div" and "mod";
  7399   - new laws about greatest common divisors (see theory ex/Primes);
  7400 
  7401 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7402 instead of "inverse";
  7403 
  7404 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7405   of the multiset ordering;
  7406 
  7407 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7408   (not included by default);
  7409 
  7410 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7411 
  7412 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7413   programs, i.e. different program variables may have different types.
  7414 
  7415 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7416   [previously, this check worked only if the rewrite rule was unconditional]
  7417   Now rew can involve either definitions or equalities (either == or =).
  7418 
  7419 
  7420 *** ZF ***
  7421 
  7422 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7423   only the theorems proved on ZF.ML;
  7424 
  7425 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7426   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7427   disjointness reasoning but breaking a few old proofs.
  7428 
  7429 * ZF/Update: new theory of function updates
  7430     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7431   may also be iterated as in f(a:=b,c:=d,...);
  7432 
  7433 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7434 
  7435 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7436   [previously, this check worked only if the rewrite rule was unconditional]
  7437   Now rew can involve either definitions or equalities (either == or =).
  7438 
  7439 * case_tac provided for compatibility with HOL
  7440     (like the old excluded_middle_tac, but with subgoals swapped)
  7441 
  7442 
  7443 *** Internal programming interfaces ***
  7444 
  7445 * Pure: several new basic modules made available for general use, see
  7446 also src/Pure/README;
  7447 
  7448 * improved the theory data mechanism to support encapsulation (data
  7449 kind name replaced by private Object.kind, acting as authorization
  7450 key); new type-safe user interface via functor TheoryDataFun; generic
  7451 print_data function becomes basically useless;
  7452 
  7453 * removed global_names compatibility flag -- all theory declarations
  7454 are qualified by default;
  7455 
  7456 * module Pure/Syntax now offers quote / antiquote translation
  7457 functions (useful for Hoare logic etc. with implicit dependencies);
  7458 see HOL/ex/Antiquote for an example use;
  7459 
  7460 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7461 cterm -> thm;
  7462 
  7463 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7464 subgoal;
  7465 
  7466 * Display.print_goals function moved to Locale.print_goals;
  7467 
  7468 * standard print function for goals supports current_goals_markers
  7469 variable for marking begin of proof, end of proof, start of goal; the
  7470 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7471 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7472 for example;
  7473 
  7474 
  7475 
  7476 New in Isabelle98 (January 1998)
  7477 --------------------------------
  7478 
  7479 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7480 
  7481 * changed lexical syntax of terms / types: dots made part of long
  7482 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7483 
  7484 * simpset (and claset) reference variable replaced by functions
  7485 simpset / simpset_ref;
  7486 
  7487 * no longer supports theory aliases (via merge) and non-trivial
  7488 implicit merge of thms' signatures;
  7489 
  7490 * most internal names of constants changed due to qualified names;
  7491 
  7492 * changed Pure/Sequence interface (see Pure/seq.ML);
  7493 
  7494 
  7495 *** General Changes ***
  7496 
  7497 * hierachically structured name spaces (for consts, types, axms, thms
  7498 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7499 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7500 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7501 long_names for fully qualified output names; NOTE: ML programs
  7502 (special tactics, packages etc.) referring to internal names may have
  7503 to be adapted to cope with fully qualified names; in case of severe
  7504 backward campatibility problems try setting 'global_names' at compile
  7505 time to have enrything declared within a flat name space; one may also
  7506 fine tune name declarations in theories via the 'global' and 'local'
  7507 section;
  7508 
  7509 * reimplemented the implicit simpset and claset using the new anytype
  7510 data filed in signatures; references simpset:simpset ref etc. are
  7511 replaced by functions simpset:unit->simpset and
  7512 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7513 to patch your ML files accordingly;
  7514 
  7515 * HTML output now includes theory graph data for display with Java
  7516 applet or isatool browser; data generated automatically via isatool
  7517 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7518 
  7519 * defs may now be conditional; improved rewrite_goals_tac to handle
  7520 conditional equations;
  7521 
  7522 * defs now admits additional type arguments, using TYPE('a) syntax;
  7523 
  7524 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7525 creates a new theory node; implicit merge of thms' signatures is
  7526 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7527 transfer:theory->thm->thm in (rare) cases;
  7528 
  7529 * improved handling of draft signatures / theories; draft thms (and
  7530 ctyps, cterms) are automatically promoted to real ones;
  7531 
  7532 * slightly changed interfaces for oracles: admit many per theory, named
  7533 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7534 
  7535 * print_goals: optional output of const types (set show_consts and
  7536 show_types);
  7537 
  7538 * improved output of warnings (###) and errors (***);
  7539 
  7540 * subgoal_tac displays a warning if the new subgoal has type variables;
  7541 
  7542 * removed old README and Makefiles;
  7543 
  7544 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7545 
  7546 * removed obsolete init_pps and init_database;
  7547 
  7548 * deleted the obsolete tactical STATE, which was declared by
  7549     fun STATE tacfun st = tacfun st st;
  7550 
  7551 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7552 (which abbreviates $HOME);
  7553 
  7554 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7555 use isatool fixseq to adapt your ML programs (this works for fully
  7556 qualified references to the Sequence structure only!);
  7557 
  7558 * use_thy no longer requires writable current directory; it always
  7559 reloads .ML *and* .thy file, if either one is out of date;
  7560 
  7561 
  7562 *** Classical Reasoner ***
  7563 
  7564 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7565 tactics that use classical reasoning to simplify a subgoal without
  7566 splitting it into several subgoals;
  7567 
  7568 * Safe_tac: like safe_tac but uses the default claset;
  7569 
  7570 
  7571 *** Simplifier ***
  7572 
  7573 * added simplification meta rules:
  7574     (asm_)(full_)simplify: simpset -> thm -> thm;
  7575 
  7576 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7577 logics (again);
  7578 
  7579 * added prems argument to simplification procedures;
  7580 
  7581 * HOL, FOL, ZF: added infix function `addsplits':
  7582   instead of `<simpset> setloop (split_tac <thms>)'
  7583   you can simply write `<simpset> addsplits <thms>'
  7584 
  7585 
  7586 *** Syntax ***
  7587 
  7588 * TYPE('a) syntax for type reflection terms;
  7589 
  7590 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7591 
  7592 * pretty printer: changed order of mixfix annotation preference (again!);
  7593 
  7594 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7595 
  7596 
  7597 *** HOL ***
  7598 
  7599 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7600   with `addloop' of the simplifier to faciliate case splitting in premises.
  7601 
  7602 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7603 
  7604 * HOL/Auth: new protocol proofs including some for the Internet
  7605   protocol TLS;
  7606 
  7607 * HOL/Map: new theory of `maps' a la VDM;
  7608 
  7609 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7610 cancelling out common nat summands from =, <, <= (in)equalities, or
  7611 differences; simplification procedures nat_cancel_factor for
  7612 cancelling common factor from =, <, <= (in)equalities over natural
  7613 sums; nat_cancel contains both kinds of procedures, it is installed by
  7614 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7615 
  7616 * HOL/simplifier: terms of the form
  7617   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7618   are rewritten to
  7619   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7620   and those of the form
  7621   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7622   are rewritten to
  7623   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7624 
  7625 * HOL/datatype
  7626   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7627 
  7628   P(t_case f1 ... fn x) =
  7629      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7630         ...
  7631        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7632      )
  7633 
  7634   and a theorem `split_t_case_asm' of the form
  7635 
  7636   P(t_case f1 ... fn x) =
  7637     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7638         ...
  7639        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7640      )
  7641   which can be added to a simpset via `addsplits'. The existing theorems
  7642   expand_list_case and expand_option_case have been renamed to
  7643   split_list_case and split_option_case.
  7644 
  7645 * HOL/Arithmetic:
  7646   - `pred n' is automatically converted to `n-1'.
  7647     Users are strongly encouraged not to use `pred' any longer,
  7648     because it will disappear altogether at some point.
  7649   - Users are strongly encouraged to write "0 < n" rather than
  7650     "n ~= 0". Theorems and proof tools have been modified towards this
  7651     `standard'.
  7652 
  7653 * HOL/Lists:
  7654   the function "set_of_list" has been renamed "set" (and its theorems too);
  7655   the function "nth" now takes its arguments in the reverse order and
  7656   has acquired the infix notation "!" as in "xs!n".
  7657 
  7658 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7659 
  7660 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7661   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7662 
  7663 * HOL/record: extensible records with schematic structural subtyping
  7664 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7665 still lacks various theorems and concrete record syntax;
  7666 
  7667 
  7668 *** HOLCF ***
  7669 
  7670 * removed "axioms" and "generated by" sections;
  7671 
  7672 * replaced "ops" section by extended "consts" section, which is capable of
  7673   handling the continuous function space "->" directly;
  7674 
  7675 * domain package:
  7676   . proves theorems immediately and stores them in the theory,
  7677   . creates hierachical name space,
  7678   . now uses normal mixfix annotations (instead of cinfix...),
  7679   . minor changes to some names and values (for consistency),
  7680   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7681   . separator between mutual domain defs: changed "," to "and",
  7682   . improved handling of sort constraints;  now they have to
  7683     appear on the left-hand side of the equations only;
  7684 
  7685 * fixed LAM <x,y,zs>.b syntax;
  7686 
  7687 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7688 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7689 
  7690 
  7691 *** FOL and ZF ***
  7692 
  7693 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7694   with `addloop' of the simplifier to faciliate case splitting in premises.
  7695 
  7696 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7697 in HOL, they strip ALL and --> from proved theorems;
  7698 
  7699 
  7700 
  7701 New in Isabelle94-8 (May 1997)
  7702 ------------------------------
  7703 
  7704 *** General Changes ***
  7705 
  7706 * new utilities to build / run / maintain Isabelle etc. (in parts
  7707 still somewhat experimental); old Makefiles etc. still functional;
  7708 
  7709 * new 'Isabelle System Manual';
  7710 
  7711 * INSTALL text, together with ./configure and ./build scripts;
  7712 
  7713 * reimplemented type inference for greater efficiency, better error
  7714 messages and clean internal interface;
  7715 
  7716 * prlim command for dealing with lots of subgoals (an easier way of
  7717 setting goals_limit);
  7718 
  7719 
  7720 *** Syntax ***
  7721 
  7722 * supports alternative (named) syntax tables (parser and pretty
  7723 printer); internal interface is provided by add_modesyntax(_i);
  7724 
  7725 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7726 be used in conjunction with the Isabelle symbol font; uses the
  7727 "symbols" syntax table;
  7728 
  7729 * added token_translation interface (may translate name tokens in
  7730 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7731 the current print_mode); IMPORTANT: user print translation functions
  7732 are responsible for marking newly introduced bounds
  7733 (Syntax.mark_boundT);
  7734 
  7735 * token translations for modes "xterm" and "xterm_color" that display
  7736 names in bold, underline etc. or colors (which requires a color
  7737 version of xterm);
  7738 
  7739 * infixes may now be declared with names independent of their syntax;
  7740 
  7741 * added typed_print_translation (like print_translation, but may
  7742 access type of constant);
  7743 
  7744 
  7745 *** Classical Reasoner ***
  7746 
  7747 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7748 some limitations.  Blast_tac...
  7749   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7750   + ignores elimination rules that don't have the correct format
  7751         (the conclusion MUST be a formula variable)
  7752   + ignores types, which can make HOL proofs fail
  7753   + rules must not require higher-order unification, e.g. apply_type in ZF
  7754     [message "Function Var's argument not a bound variable" relates to this]
  7755   + its proof strategy is more general but can actually be slower
  7756 
  7757 * substitution with equality assumptions no longer permutes other
  7758 assumptions;
  7759 
  7760 * minor changes in semantics of addafter (now called addaltern); renamed
  7761 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7762 (and access functions for it);
  7763 
  7764 * improved combination of classical reasoner and simplifier:
  7765   + functions for handling clasimpsets
  7766   + improvement of addss: now the simplifier is called _after_ the
  7767     safe steps.
  7768   + safe variant of addss called addSss: uses safe simplifications
  7769     _during_ the safe steps. It is more complete as it allows multiple
  7770     instantiations of unknowns (e.g. with slow_tac).
  7771 
  7772 *** Simplifier ***
  7773 
  7774 * added interface for simplification procedures (functions that
  7775 produce *proven* rewrite rules on the fly, depending on current
  7776 redex);
  7777 
  7778 * ordering on terms as parameter (used for ordered rewriting);
  7779 
  7780 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7781 
  7782 * the solver is now split into a safe and an unsafe part.
  7783 This should be invisible for the normal user, except that the
  7784 functions setsolver and addsolver have been renamed to setSolver and
  7785 addSolver; added safe_asm_full_simp_tac;
  7786 
  7787 
  7788 *** HOL ***
  7789 
  7790 * a generic induction tactic `induct_tac' which works for all datatypes and
  7791 also for type `nat';
  7792 
  7793 * a generic case distinction tactic `exhaust_tac' which works for all
  7794 datatypes and also for type `nat';
  7795 
  7796 * each datatype comes with a function `size';
  7797 
  7798 * patterns in case expressions allow tuple patterns as arguments to
  7799 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7800 
  7801 * primrec now also works with type nat;
  7802 
  7803 * recdef: a new declaration form, allows general recursive functions to be
  7804 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7805 
  7806 * the constant for negation has been renamed from "not" to "Not" to
  7807 harmonize with FOL, ZF, LK, etc.;
  7808 
  7809 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7810 infinite lists;
  7811 
  7812 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7813 
  7814 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7815 problems in commutative rings, using axiomatic type classes for + and *;
  7816 
  7817 * more examples in HOL/MiniML and HOL/Auth;
  7818 
  7819 * more default rewrite rules for quantifiers, union/intersection;
  7820 
  7821 * a new constant `arbitrary == @x.False';
  7822 
  7823 * HOLCF/IOA replaces old HOL/IOA;
  7824 
  7825 * HOLCF changes: derived all rules and arities
  7826   + axiomatic type classes instead of classes
  7827   + typedef instead of faking type definitions
  7828   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7829   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7830   + eliminated the types void, one, tr
  7831   + use unit lift and bool lift (with translations) instead of one and tr
  7832   + eliminated blift from Lift3.thy (use Def instead of blift)
  7833   all eliminated rules are derived as theorems --> no visible changes ;
  7834 
  7835 
  7836 *** ZF ***
  7837 
  7838 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  7839 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  7840 as ZF_cs addSIs [equalityI];
  7841 
  7842 
  7843 
  7844 New in Isabelle94-7 (November 96)
  7845 ---------------------------------
  7846 
  7847 * allowing negative levels (as offsets) in prlev and choplev;
  7848 
  7849 * super-linear speedup for large simplifications;
  7850 
  7851 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  7852 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  7853 FAIL); can suppress it using the command Delsimps (ex_simps @
  7854 all_simps); De Morgan laws are also now included, by default;
  7855 
  7856 * improved printing of ==>  :  ~:
  7857 
  7858 * new object-logic "Sequents" adds linear logic, while replacing LK
  7859 and Modal (thanks to Sara Kalvala);
  7860 
  7861 * HOL/Auth: correctness proofs for authentication protocols;
  7862 
  7863 * HOL: new auto_tac combines rewriting and classical reasoning (many
  7864 examples on HOL/Auth);
  7865 
  7866 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  7867 the rewriter and classical reasoner simultaneously;
  7868 
  7869 * function uresult no longer returns theorems in "standard" format;
  7870 regain previous version by: val uresult = standard o uresult;
  7871 
  7872 
  7873 
  7874 New in Isabelle94-6
  7875 -------------------
  7876 
  7877 * oracles -- these establish an interface between Isabelle and trusted
  7878 external reasoners, which may deliver results as theorems;
  7879 
  7880 * proof objects (in particular record all uses of oracles);
  7881 
  7882 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  7883 
  7884 * "constdefs" section in theory files;
  7885 
  7886 * "primrec" section (HOL) no longer requires names;
  7887 
  7888 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  7889 
  7890 
  7891 
  7892 New in Isabelle94-5
  7893 -------------------
  7894 
  7895 * reduced space requirements;
  7896 
  7897 * automatic HTML generation from theories;
  7898 
  7899 * theory files no longer require "..." (quotes) around most types;
  7900 
  7901 * new examples, including two proofs of the Church-Rosser theorem;
  7902 
  7903 * non-curried (1994) version of HOL is no longer distributed;
  7904 
  7905 
  7906 
  7907 New in Isabelle94-4
  7908 -------------------
  7909 
  7910 * greatly reduced space requirements;
  7911 
  7912 * theory files (.thy) no longer require \...\ escapes at line breaks;
  7913 
  7914 * searchable theorem database (see the section "Retrieving theorems" on
  7915 page 8 of the Reference Manual);
  7916 
  7917 * new examples, including Grabczewski's monumental case study of the
  7918 Axiom of Choice;
  7919 
  7920 * The previous version of HOL renamed to Old_HOL;
  7921 
  7922 * The new version of HOL (previously called CHOL) uses a curried syntax
  7923 for functions.  Application looks like f a b instead of f(a,b);
  7924 
  7925 * Mutually recursive inductive definitions finally work in HOL;
  7926 
  7927 * In ZF, pattern-matching on tuples is now available in all abstractions and
  7928 translates to the operator "split";
  7929 
  7930 
  7931 
  7932 New in Isabelle94-3
  7933 -------------------
  7934 
  7935 * new infix operator, addss, allowing the classical reasoner to
  7936 perform simplification at each step of its search.  Example:
  7937         fast_tac (cs addss ss)
  7938 
  7939 * a new logic, CHOL, the same as HOL, but with a curried syntax
  7940 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  7941 look like (a,b) instead of <a,b>;
  7942 
  7943 * PLEASE NOTE: CHOL will eventually replace HOL!
  7944 
  7945 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  7946 It translates to the operator "split".  A new theory of integers is available;
  7947 
  7948 * In ZF, integer numerals now denote two's-complement binary integers.
  7949 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  7950 
  7951 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  7952 of the Axiom of Choice;
  7953 
  7954 
  7955 
  7956 New in Isabelle94-2
  7957 -------------------
  7958 
  7959 * Significantly faster resolution;
  7960 
  7961 * the different sections in a .thy file can now be mixed and repeated
  7962 freely;
  7963 
  7964 * Database of theorems for FOL, HOL and ZF.  New
  7965 commands including qed, qed_goal and bind_thm store theorems in the database.
  7966 
  7967 * Simple database queries: return a named theorem (get_thm) or all theorems of
  7968 a given theory (thms_of), or find out what theory a theorem was proved in
  7969 (theory_of_thm);
  7970 
  7971 * Bugs fixed in the inductive definition and datatype packages;
  7972 
  7973 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  7974 and HOL_dup_cs obsolete;
  7975 
  7976 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  7977 have been removed;
  7978 
  7979 * Simpler definition of function space in ZF;
  7980 
  7981 * new results about cardinal and ordinal arithmetic in ZF;
  7982 
  7983 * 'subtype' facility in HOL for introducing new types as subsets of existing
  7984 types;
  7985 
  7986 :mode=text:wrap=hard:maxLineLen=72: