NEWS
author haftmann
Mon Nov 29 13:44:54 2010 +0100 (2010-11-29)
changeset 40815 6e2d17cc0d1d
parent 40780 1cabd6f4a718
child 40821 9f32d7b8b24f
permissions -rw-r--r--
equivI has replaced equiv.intro
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
    10 (and thus refers to something like $HOME/.isabelle/IsabelleXXXX),
    11 while the default heap location within that directory lacks that extra
    12 suffix.  This isolates multiple Isabelle installations from each
    13 other, avoiding problems with old settings in new versions.
    14 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
    15 
    16 * Significantly improved Isabelle/Isar implementation manual.
    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 * Theory loading: only the master source file is looked-up in the
    27 implicit load path, all other files are addressed relatively to its
    28 directory.  Minor INCOMPATIBILITY, subtle change in semantics.
    29 
    30 * Special treatment of ML file names has been discontinued.
    31 Historically, optional extensions .ML or .sml were added on demand --
    32 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    33 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    34 
    35 * Various options that affect pretty printing etc. are now properly
    36 handled within the context via configuration options, instead of
    37 unsynchronized references.  There are both ML Config.T entities and
    38 Isar declaration attributes to access these.
    39 
    40   ML (Config.T)                 Isar (attribute)
    41 
    42   eta_contract                  eta_contract
    43   show_brackets                 show_brackets
    44   show_sorts                    show_sorts
    45   show_types                    show_types
    46   show_question_marks           show_question_marks
    47   show_consts                   show_consts
    48 
    49   Syntax.ambiguity_level        syntax_ambiguity_level
    50 
    51   Goal_Display.goals_limit      goals_limit
    52   Goal_Display.show_main_goal   show_main_goal
    53 
    54   Thy_Output.display            thy_output_display
    55   Thy_Output.quotes             thy_output_quotes
    56   Thy_Output.indent             thy_output_indent
    57   Thy_Output.source             thy_output_source
    58   Thy_Output.break              thy_output_break
    59 
    60 Note that corresponding "..._default" references in ML may be only
    61 changed globally at the ROOT session setup, but *not* within a theory.
    62 
    63 
    64 *** Pure ***
    65 
    66 * Support for real valued configuration options, using simplistic
    67 floating-point notation that coincides with the inner syntax for
    68 float_token.
    69 
    70 * Support for real valued preferences (with approximative PGIP type).
    71 
    72 * Interpretation command 'interpret' accepts a list of equations like
    73 'interpretation' does.
    74 
    75 * Diagnostic command 'print_interps' prints interpretations in proofs
    76 in addition to interpretations in theories.
    77 
    78 * Discontinued obsolete 'global' and 'local' commands to manipulate
    79 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
    80 Sign.root_path and Sign.local_path may be applied directly where this
    81 feature is still required for historical reasons.
    82 
    83 * Discontinued ancient 'constdefs' command.  INCOMPATIBILITY, use
    84 'definition' instead.
    85 
    86 * Document antiquotations @{class} and @{type} for printing classes
    87 and type constructors.
    88 
    89 
    90 *** HOL ***
    91 
    92 * Abandoned locale equiv for equivalence relations.  INCOMPATIBILITY: use
    93 equivI rather than equiv_intro.
    94 
    95 * Code generator: globbing constant expressions "*" and "Theory.*" have been
    96 replaced by the more idiomatic "_" and "Theory._".  INCOMPATIBILITY.
    97 
    98 * Theory Enum (for explicit enumerations of finite types) is now part of
    99 the HOL-Main image. INCOMPATIBILITY: All constants of the Enum theory now 
   100 have to be referred to by its qualified name.
   101   constants
   102     enum -> Enum.enum
   103     nlists -> Enum.nlists
   104     product -> Enum.product
   105 
   106 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   107 avoid confusion with finite sets.  INCOMPATIBILITY.
   108 
   109 * Quickcheck's generator for random generation is renamed from "code" to
   110 "random".  INCOMPATIBILITY.
   111 
   112 * Theory Multiset provides stable quicksort implementation of sort_key.
   113 
   114 * Quickcheck now has a configurable time limit which is set to 30 seconds
   115 by default. This can be changed by adding [timeout = n] to the quickcheck
   116 command. The time limit for Auto Quickcheck is still set independently.
   117 
   118 * New command 'partial_function' provides basic support for recursive
   119 function definitions over complete partial orders. Concrete instances
   120 are provided for i) the option type, ii) tail recursion on arbitrary
   121 types, and iii) the heap monad of Imperative_HOL. See
   122 HOL/ex/Fundefs.thy and HOL/Imperative_HOL/ex/Linked_Lists.thy for
   123 examples.
   124 
   125 * Predicates `distinct` and `sorted` now defined inductively, with nice
   126 induction rules.  INCOMPATIBILITY: former distinct.simps and sorted.simps
   127 now named distinct_simps and sorted_simps.
   128 
   129 * Constant `contents` renamed to `the_elem`, to free the generic name
   130 contents for other uses.  INCOMPATIBILITY.
   131 
   132 * Dropped syntax for old primrec package.  INCOMPATIBILITY.
   133 
   134 * Improved infrastructure for term evaluation using code generator
   135 techniques, in particular static evaluation conversions.
   136 
   137 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   138  
   139 * Renamed lemmas:
   140   expand_fun_eq -> fun_eq_iff
   141   expand_set_eq -> set_eq_iff
   142   set_ext -> set_eqI
   143  INCOMPATIBILITY.
   144 
   145 * Renamed lemma list: nat_number -> eval_nat_numeral
   146 
   147 * Renamed class eq and constant eq (for code generation) to class equal
   148 and constant equal, plus renaming of related facts and various tuning.
   149 INCOMPATIBILITY.
   150 
   151 * Scala (2.8 or higher) has been added to the target languages of
   152 the code generator.
   153 
   154 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   155 
   156 * Removed output syntax "'a ~=> 'b" for "'a => 'b option". INCOMPATIBILITY.
   157 
   158 * Theory SetsAndFunctions has been split into Function_Algebras and Set_Algebras;
   159 canonical names for instance definitions for functions; various improvements.
   160 INCOMPATIBILITY.
   161 
   162 * Records: logical foundation type for records do not carry a '_type' suffix
   163 any longer.  INCOMPATIBILITY.
   164 
   165 * Code generation for records: more idiomatic representation of record types.
   166 Warning: records are not covered by ancient SML code generation any longer.
   167 INCOMPATIBILITY.  In cases of need, a suitable rep_datatype declaration
   168 helps to succeed then:
   169 
   170   record 'a foo = ...
   171   ...
   172   rep_datatype foo_ext ...
   173 
   174 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   175 INCOMPATIBILITY.
   176 
   177 * Quickcheck in locales considers interpretations of that locale for
   178 counter example search.
   179 
   180 * Theory Library/Monad_Syntax provides do-syntax for monad types.  Syntax
   181 in Library/State_Monad has been changed to avoid ambiguities.
   182 INCOMPATIBILITY.
   183 
   184 * Code generator: export_code without explicit file declaration prints
   185 to standard output.  INCOMPATIBILITY.
   186 
   187 * Abolished symbol type names:  "prod" and "sum" replace "*" and "+"
   188 respectively.  INCOMPATIBILITY.
   189 
   190 * Name "Plus" of disjoint sum operator "<+>" is now hidden.
   191   Write Sum_Type.Plus.
   192 
   193 * Constant "split" has been merged with constant "prod_case";  names
   194 of ML functions, facts etc. involving split have been retained so far,
   195 though.  INCOMPATIBILITY.
   196 
   197 * Dropped old infix syntax "mem" for List.member;  use "in set"
   198 instead.  INCOMPATIBILITY.
   199 
   200 * Refactoring of code-generation specific operations in List.thy
   201 
   202   constants
   203     null ~> List.null
   204 
   205   facts
   206     mem_iff ~> member_def
   207     null_empty ~> null_def
   208 
   209 INCOMPATIBILITY.  Note that these were not suppossed to be used
   210 regularly unless for striking reasons;  their main purpose was code
   211 generation.
   212 
   213 * Some previously unqualified names have been qualified:
   214 
   215   types
   216     bool ~> HOL.bool
   217     nat ~> Nat.nat
   218 
   219   constants
   220     Trueprop ~> HOL.Trueprop
   221     True ~> HOL.True
   222     False ~> HOL.False
   223     op & ~> HOL.conj
   224     op | ~> HOL.disj
   225     op --> ~> HOL.implies
   226     op = ~> HOL.eq
   227     Not ~> HOL.Not
   228     The ~> HOL.The
   229     All ~> HOL.All
   230     Ex ~> HOL.Ex
   231     Ex1 ~> HOL.Ex1
   232     Let ~> HOL.Let
   233     If ~> HOL.If
   234     Ball ~> Set.Ball
   235     Bex ~> Set.Bex
   236     Suc ~> Nat.Suc
   237     Pair ~> Product_Type.Pair
   238     fst ~> Product_Type.fst
   239     snd ~> Product_Type.snd
   240     curry ~> Product_Type.curry
   241     op : ~> Set.member
   242     Collect ~> Set.Collect
   243 
   244 INCOMPATIBILITY.
   245 
   246 * Removed simplifier congruence rule of "prod_case", as has for long
   247 been the case with "split".  INCOMPATIBILITY.
   248 
   249 * Datatype package: theorems generated for executable equality
   250 (class eq) carry proper names and are treated as default code
   251 equations.
   252 
   253 * Removed lemma Option.is_none_none (Duplicate of is_none_def).
   254 INCOMPATIBILITY.
   255 
   256 * List.thy: use various operations from the Haskell prelude when
   257 generating Haskell code.
   258 
   259 * Multiset.thy: renamed empty_idemp -> empty_neutral
   260 
   261 * code_simp.ML and method code_simp: simplification with rules determined
   262 by code generator.
   263 
   264 * code generator: do not print function definitions for case
   265 combinators any longer.
   266 
   267 * Multivariate Analysis: Introduced a type class for euclidean space. Most
   268 theorems are now stated in terms of euclidean spaces instead of finite
   269 cartesian products.
   270 
   271   types
   272     real ^ 'n ~>  'a::real_vector
   273               ~>  'a::euclidean_space
   274               ~>  'a::ordered_euclidean_space
   275         (depends on your needs)
   276 
   277   constants
   278      _ $ _        ~> _ $$ _
   279      \<chi> x. _  ~> \<chi>\<chi> x. _
   280      CARD('n)     ~> DIM('a)
   281 
   282 Also note that the indices are now natural numbers and not from some finite
   283 type. Finite cartesian products of euclidean spaces, products of euclidean
   284 spaces the real and complex numbers are instantiated to be euclidean_spaces.
   285 
   286 INCOMPATIBILITY.
   287 
   288 * Probability: Introduced pinfreal as real numbers with infinity. Use pinfreal
   289 as value for measures. Introduces Lebesgue Measure based on the integral in
   290 Multivariate Analysis. Proved Radon Nikodym for arbitrary sigma finite measure
   291 spaces.
   292 
   293  INCOMPATIBILITY.
   294 
   295 * Inductive package: offers new command "inductive_simps" to automatically
   296 derive instantiated and simplified equations for inductive predicates,
   297 similar to inductive_cases.
   298 
   299 * "bij f" is now an abbreviation of "bij_betw f UNIV UNIV". "surj f"
   300 is now an abbreviation of "range f = UNIV". The theorems bij_def and
   301 surj_def are unchanged.  INCOMPATIBILITY.
   302 
   303 * Function package: .psimps rules are no longer implicitly declared [simp].
   304 INCOMPATIBILITY.
   305 
   306 * Weaker versions of the "meson" and "metis" proof methods are now available in
   307   "HOL-Plain", without dependency on "Hilbert_Choice". The proof methods become
   308   more powerful after "Hilbert_Choice" is loaded in "HOL-Main".
   309 
   310 * MESON: Renamed lemmas:
   311   meson_not_conjD ~> Meson.not_conjD
   312   meson_not_disjD ~> Meson.not_disjD
   313   meson_not_notD ~> Meson.not_notD
   314   meson_not_allD ~> Meson.not_allD
   315   meson_not_exD ~> Meson.not_exD
   316   meson_imp_to_disjD ~> Meson.imp_to_disjD
   317   meson_not_impD ~> Meson.not_impD
   318   meson_iff_to_disjD ~> Meson.iff_to_disjD
   319   meson_not_iffD ~> Meson.not_iffD
   320   meson_not_refl_disj_D ~> Meson.not_refl_disj_D
   321   meson_conj_exD1 ~> Meson.conj_exD1
   322   meson_conj_exD2 ~> Meson.conj_exD2
   323   meson_disj_exD ~> Meson.disj_exD
   324   meson_disj_exD1 ~> Meson.disj_exD1
   325   meson_disj_exD2 ~> Meson.disj_exD2
   326   meson_disj_assoc ~> Meson.disj_assoc
   327   meson_disj_comm ~> Meson.disj_comm
   328   meson_disj_FalseD1 ~> Meson.disj_FalseD1
   329   meson_disj_FalseD2 ~> Meson.disj_FalseD2
   330 INCOMPATIBILITY.
   331 
   332 * Auto Solve: Renamed "Auto Solve Direct". The tool is now available manually as
   333   "solve_direct".
   334 
   335 * Sledgehammer:
   336   - Added "smt" and "remote_smt" provers based on the "smt" proof method. See
   337     the Sledgehammer manual for details ("isabelle doc sledgehammer").
   338   - Renamed lemmas:
   339     COMBI_def ~> Meson.COMBI_def
   340     COMBK_def ~> Meson.COMBK_def
   341     COMBB_def ~> Meson.COMBB_def
   342     COMBC_def ~> Meson.COMBC_def
   343     COMBS_def ~> Meson.COMBS_def
   344     abs_I ~> Meson.abs_I
   345     abs_K ~> Meson.abs_K
   346     abs_B ~> Meson.abs_B
   347     abs_C ~> Meson.abs_C
   348     abs_S ~> Meson.abs_S
   349     INCOMPATIBILITY.
   350   - Renamed commands:
   351     sledgehammer atp_info ~> sledgehammer running_provers
   352     sledgehammer atp_kill ~> sledgehammer kill_provers
   353     sledgehammer available_atps ~> sledgehammer available_provers
   354     INCOMPATIBILITY.
   355   - Renamed options:
   356     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   357     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   358     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   359     (and "ms" and "min" are no longer supported)
   360     INCOMPATIBILITY.
   361 
   362 * Metis and Meson now have configuration options "meson_trace", "metis_trace",
   363   and "metis_verbose" that can be enabled to diagnose these tools. E.g.
   364 
   365     using [[metis_trace = true]]
   366 
   367 * Nitpick:
   368   - Renamed options:
   369     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   370     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   371     INCOMPATIBILITY.
   372   - Now requires Kodkodi 1.2.9. INCOMPATIBILITY.
   373   - Added support for partial quotient types.
   374   - Added local versions of the "Nitpick.register_xxx" functions.
   375   - Added "whack" option.
   376   - Allow registration of quotient types as codatatypes.
   377   - Improved "merge_type_vars" option to merge more types.
   378   - Removed unsound "fast_descrs" option.
   379   - Added custom symmetry breaking for datatypes, making it possible to reach
   380     higher cardinalities.
   381   - Prevent the expansion of too large definitions.
   382 
   383 * Changed SMT configuration options:
   384   - Renamed:
   385     z3_proofs ~> smt_oracle (with swapped semantics)
   386     z3_trace_assms ~> smt_trace_used_facts
   387     INCOMPATIBILITY.
   388   - Added:
   389     smt_verbose
   390     smt_datatypes
   391     cvc3_options
   392     yices_options
   393 
   394 * Boogie output files (.b2i files) need to be declared in the
   395 theory header.
   396 
   397 * Removed [split_format ... and ... and ...] version of
   398 [split_format].  Potential INCOMPATIBILITY.
   399 
   400 
   401 *** HOLCF ***
   402 
   403 * The domain package now runs in definitional mode by default: The
   404 former command 'new_domain' is now called 'domain'. To use the domain
   405 package in its original axiomatic mode, use 'domain (unsafe)'.
   406 INCOMPATIBILITY.
   407 
   408 * The new class 'domain' is now the default sort; the definitional
   409 domain package and the powerdomain theories both require this class.
   410 The new class 'predomain' is an unpointed version of 'domain'.
   411 Theories can be updated by replacing sort annotations as shown below.
   412 INCOMPATIBILITY.
   413 
   414   'a::type ~> 'a::countable
   415   'a::cpo  ~> 'a::predomain
   416   'a::pcpo ~> 'a::domain
   417 
   418 * The old type class 'rep' has been superseded by class 'domain'.
   419 Accordingly, users of the definitional package must remove any
   420 'default_sort rep' declarations. INCOMPATIBILITY.
   421 
   422 * The old type classes 'profinite' and 'bifinite', along with the
   423 overloaded constant 'approx' have been removed. INCOMPATIBILITY.
   424 
   425 * The type 'udom alg_defl' has been replaced by the non-parameterized
   426 type 'defl'. HOLCF no longer defines an embedding of type defl into
   427 udom by default; the instance proof defl :: domain is now available in
   428 HOLCF/Library/Defl_Bifinite.thy.
   429 
   430 * The syntax 'REP('a)' has been replaced with 'DEFL('a)'.
   431 
   432 * The predicate 'directed' has been removed. INCOMPATIBILITY.
   433 
   434 * The type class 'finite_po' has been removed. INCOMPATIBILITY.
   435 
   436 * Renamed some theorems (the original names are also still available).
   437   expand_fun_below   ~> fun_below_iff
   438   below_fun_ext      ~> fun_belowI
   439   expand_cfun_eq     ~> cfun_eq_iff
   440   ext_cfun           ~> cfun_eqI
   441   expand_cfun_below  ~> cfun_below_iff
   442   below_cfun_ext     ~> cfun_belowI
   443   cont2cont_Rep_CFun ~> cont2cont_APP
   444 
   445 * The Abs and Rep functions for various types have changed names.
   446 Related theorem names have also changed to match. INCOMPATIBILITY. 
   447   Rep_CFun  ~> Rep_cfun
   448   Abs_CFun  ~> Abs_cfun
   449   Rep_Sprod ~> Rep_sprod
   450   Abs_Sprod ~> Abs_sprod
   451   Rep_Ssum  ~> Rep_ssum
   452   Abs_Ssum  ~> Abs_ssum
   453 
   454 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   455 been renamed to *_bottom_iff. INCOMPATIBILITY.
   456 
   457 * Various changes to bisimulation/coinduction with domain package:
   458   - Definitions of 'bisim' constants no longer mention definedness.
   459   - With mutual recursion, 'bisim' predicate is now curried.
   460   - With mutual recursion, each type gets a separate coind theorem.
   461   - Variable names in bisim_def and coinduct rules have changed.
   462 INCOMPATIBILITY.
   463 
   464 * Case combinators generated by the domain package for type 'foo'
   465 are now named 'foo_case' instead of 'foo_when'. INCOMPATIBILITY.
   466 
   467 * Several theorems have been renamed to more accurately reflect the
   468 names of constants and types involved. INCOMPATIBILITY.
   469   thelub_const    ~> lub_const
   470   lub_const       ~> is_lub_const
   471   thelubI         ~> lub_eqI
   472   is_lub_lub      ~> is_lubD2
   473   lubI            ~> is_lub_lub
   474   unique_lub      ~> is_lub_unique
   475   is_ub_lub       ~> is_lub_rangeD1
   476   lub_bin_chain   ~> is_lub_bin_chain
   477   thelub_Pair     ~> lub_Pair
   478   lub_cprod       ~> is_lub_prod
   479   thelub_cprod    ~> lub_prod
   480   minimal_cprod   ~> minimal_prod
   481   inst_cprod_pcpo ~> inst_prod_pcpo
   482 
   483 * Many legacy theorem names have been discontinued. INCOMPATIBILITY.
   484   sq_ord_less_eq_trans ~> below_eq_trans
   485   sq_ord_eq_less_trans ~> eq_below_trans
   486   refl_less            ~> below_refl
   487   trans_less           ~> below_trans
   488   antisym_less         ~> below_antisym
   489   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   490   box_less             ~> box_below
   491   rev_trans_less       ~> rev_below_trans
   492   not_less2not_eq      ~> not_below2not_eq
   493   less_UU_iff          ~> below_UU_iff
   494   flat_less_iff        ~> flat_below_iff
   495   adm_less             ~> adm_below
   496   adm_not_less         ~> adm_not_below
   497   adm_compact_not_less ~> adm_compact_not_below
   498   less_fun_def         ~> below_fun_def
   499   expand_fun_less      ~> fun_below_iff
   500   less_fun_ext         ~> fun_belowI
   501   less_discr_def       ~> below_discr_def
   502   discr_less_eq        ~> discr_below_eq
   503   less_unit_def        ~> below_unit_def
   504   less_cprod_def       ~> below_prod_def
   505   prod_lessI           ~> prod_belowI
   506   Pair_less_iff        ~> Pair_below_iff
   507   fst_less_iff         ~> fst_below_iff
   508   snd_less_iff         ~> snd_below_iff
   509   expand_cfun_less     ~> cfun_below_iff
   510   less_cfun_ext        ~> cfun_belowI
   511   injection_less       ~> injection_below
   512   less_up_def          ~> below_up_def
   513   not_Iup_less         ~> not_Iup_below
   514   Iup_less             ~> Iup_below
   515   up_less              ~> up_below
   516   Def_inject_less_eq   ~> Def_below_Def
   517   Def_less_is_eq       ~> Def_below_iff
   518   spair_less_iff       ~> spair_below_iff
   519   less_sprod           ~> below_sprod
   520   spair_less           ~> spair_below
   521   sfst_less_iff        ~> sfst_below_iff
   522   ssnd_less_iff        ~> ssnd_below_iff
   523   fix_least_less       ~> fix_least_below
   524   dist_less_one        ~> dist_below_one
   525   less_ONE             ~> below_ONE
   526   ONE_less_iff         ~> ONE_below_iff
   527   less_sinlD           ~> below_sinlD
   528   less_sinrD           ~> below_sinrD
   529 
   530 
   531 *** FOL ***
   532 
   533 * All constant names are now qualified.  INCOMPATIBILITY.
   534 
   535 
   536 *** ZF ***
   537 
   538 * All constant names are now qualified.  INCOMPATIBILITY.
   539 
   540 
   541 *** ML ***
   542 
   543 * Former exception Library.UnequalLengths now coincides with
   544 ListPair.UnequalLengths.
   545 
   546 * Renamed raw "explode" function to "raw_explode" to emphasize its
   547 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   548 almost all situations.
   549 
   550 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   551 See implementation manual for further details on exceptions in
   552 Isabelle/ML.
   553 
   554 * Antiquotation @{assert} inlines a function bool -> unit that raises
   555 Fail if the argument is false.  Due to inlining the source position of
   556 failed assertions is included in the error output.
   557 
   558 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   559 text is in practice always evaluated with a stable theory checkpoint.
   560 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   561 
   562 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   563 meaning.
   564 
   565 * Renamed structure PureThy to Pure_Thy and moved most of its
   566 operations to structure Global_Theory, to emphasize that this is
   567 rarely-used global-only stuff.
   568 
   569 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   570 instead (or tracing for high-volume output).
   571 
   572 * Configuration option show_question_marks only affects regular pretty
   573 printing of types and terms, not raw Term.string_of_vname.
   574 
   575 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   576 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   577 @{thms} for most purposes.
   578 
   579 * ML structure Unsynchronized never opened, not even in Isar
   580 interaction mode as before.  Old Unsynchronized.set etc. have been
   581 discontinued -- use plain := instead.  This should be *rare* anyway,
   582 since modern tools always work via official context data, notably
   583 configuration options.
   584 
   585 * ML antiquotations @{theory} and @{theory_ref} refer to named
   586 theories from the ancestry of the current context, not any accidental
   587 theory loader state as before.  Potential INCOMPATIBILITY, subtle
   588 change in semantics.
   589 
   590 * Parallel and asynchronous execution requires special care concerning
   591 interrupts.  Structure Exn provides some convenience functions that
   592 avoid working directly with raw Interrupt.  User code must not absorb
   593 interrupts -- intermediate handling (for cleanup etc.) needs to be
   594 followed by re-raising of the original exception.  Another common
   595 source of mistakes are "handle _" patterns, which make the meaning of
   596 the program subject to physical effects of the environment.
   597 
   598 
   599 *** System ***
   600 
   601 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   602 
   603 
   604 
   605 New in Isabelle2009-2 (June 2010)
   606 ---------------------------------
   607 
   608 *** General ***
   609 
   610 * Authentic syntax for *all* logical entities (type classes, type
   611 constructors, term constants): provides simple and robust
   612 correspondence between formal entities and concrete syntax.  Within
   613 the parse tree / AST representations, "constants" are decorated by
   614 their category (class, type, const) and spelled out explicitly with
   615 their full internal name.
   616 
   617 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   618 and translations (translation rules and translation functions in ML).
   619 Some hints on upgrading:
   620 
   621   - Many existing uses of 'syntax' and 'translations' can be replaced
   622     by more modern 'type_notation', 'notation' and 'abbreviation',
   623     which are independent of this issue.
   624 
   625   - 'translations' require markup within the AST; the term syntax
   626     provides the following special forms:
   627 
   628       CONST c   -- produces syntax version of constant c from context
   629       XCONST c  -- literally c, checked as constant from context
   630       c         -- literally c, if declared by 'syntax'
   631 
   632     Plain identifiers are treated as AST variables -- occasionally the
   633     system indicates accidental variables via the error "rhs contains
   634     extra variables".
   635 
   636     Type classes and type constructors are marked according to their
   637     concrete syntax.  Some old translations rules need to be written
   638     for the "type" category, using type constructor application
   639     instead of pseudo-term application of the default category
   640     "logic".
   641 
   642   - 'parse_translation' etc. in ML may use the following
   643     antiquotations:
   644 
   645       @{class_syntax c}   -- type class c within parse tree / AST
   646       @{term_syntax c}    -- type constructor c within parse tree / AST
   647       @{const_syntax c}   -- ML version of "CONST c" above
   648       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   649 
   650   - Literal types within 'typed_print_translations', i.e. those *not*
   651     represented as pseudo-terms are represented verbatim.  Use @{class
   652     c} or @{type_name c} here instead of the above syntax
   653     antiquotations.
   654 
   655 Note that old non-authentic syntax was based on unqualified base
   656 names, so all of the above "constant" names would coincide.  Recall
   657 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   658 diagnose syntax problems.
   659 
   660 * Type constructors admit general mixfix syntax, not just infix.
   661 
   662 * Concrete syntax may be attached to local entities without a proof
   663 body, too.  This works via regular mixfix annotations for 'fix',
   664 'def', 'obtain' etc. or via the explicit 'write' command, which is
   665 similar to the 'notation' command in theory specifications.
   666 
   667 * Discontinued unnamed infix syntax (legacy feature for many years) --
   668 need to specify constant name and syntax separately.  Internal ML
   669 datatype constructors have been renamed from InfixName to Infix etc.
   670 Minor INCOMPATIBILITY.
   671 
   672 * Schematic theorem statements need to be explicitly markup as such,
   673 via commands 'schematic_lemma', 'schematic_theorem',
   674 'schematic_corollary'.  Thus the relevance of the proof is made
   675 syntactically clear, which impacts performance in a parallel or
   676 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   677 
   678 * Use of cumulative prems via "!" in some proof methods has been
   679 discontinued (old legacy feature).
   680 
   681 * References 'trace_simp' and 'debug_simp' have been replaced by
   682 configuration options stored in the context. Enabling tracing (the
   683 case of debugging is similar) in proofs works via
   684 
   685   using [[trace_simp = true]]
   686 
   687 Tracing is then active for all invocations of the simplifier in
   688 subsequent goal refinement steps. Tracing may also still be enabled or
   689 disabled via the ProofGeneral settings menu.
   690 
   691 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   692 'hide_fact' replace the former 'hide' KIND command.  Minor
   693 INCOMPATIBILITY.
   694 
   695 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   696 more efficient than combinations with -q1 or -q2.
   697 
   698 
   699 *** Pure ***
   700 
   701 * Proofterms record type-class reasoning explicitly, using the
   702 "unconstrain" operation internally.  This eliminates all sort
   703 constraints from a theorem and proof, introducing explicit
   704 OFCLASS-premises.  On the proof term level, this operation is
   705 automatically applied at theorem boundaries, such that closed proofs
   706 are always free of sort constraints.  INCOMPATIBILITY for tools that
   707 inspect proof terms.
   708 
   709 * Local theory specifications may depend on extra type variables that
   710 are not present in the result type -- arguments TYPE('a) :: 'a itself
   711 are added internally.  For example:
   712 
   713   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   714 
   715 * Predicates of locales introduced by classes carry a mandatory
   716 "class" prefix.  INCOMPATIBILITY.
   717 
   718 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   719 
   720 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   721 'class' instead.
   722 
   723 * Command 'code_reflect' allows to incorporate generated ML code into
   724 runtime environment; replaces immature code_datatype antiquotation.
   725 INCOMPATIBILITY.
   726 
   727 * Code generator: simple concept for abstract datatypes obeying
   728 invariants.
   729 
   730 * Code generator: details of internal data cache have no impact on the
   731 user space functionality any longer.
   732 
   733 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   734 subgoals.  This is more appropriate for interpretations with 'where'.
   735 INCOMPATIBILITY.
   736 
   737 * Command 'example_proof' opens an empty proof body.  This allows to
   738 experiment with Isar, without producing any persistent result.
   739 
   740 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   741 within a local theory context, with explicit checking of the
   742 constructors involved (in contrast to the raw 'syntax' versions).
   743 
   744 * Commands 'types' and 'typedecl' now work within a local theory
   745 context -- without introducing dependencies on parameters or
   746 assumptions, which is not possible in Isabelle/Pure.
   747 
   748 * Command 'defaultsort' has been renamed to 'default_sort', it works
   749 within a local theory context.  Minor INCOMPATIBILITY.
   750 
   751 
   752 *** HOL ***
   753 
   754 * Command 'typedef' now works within a local theory context -- without
   755 introducing dependencies on parameters or assumptions, which is not
   756 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   757 contain multiple interpretations of local typedefs (with different
   758 non-emptiness proofs), even in a global theory context.
   759 
   760 * New package for quotient types.  Commands 'quotient_type' and
   761 'quotient_definition' may be used for defining types and constants by
   762 quotient constructions.  An example is the type of integers created by
   763 quotienting pairs of natural numbers:
   764 
   765   fun
   766     intrel :: "(nat * nat) => (nat * nat) => bool"
   767   where
   768     "intrel (x, y) (u, v) = (x + v = u + y)"
   769 
   770   quotient_type int = "nat * nat" / intrel
   771     by (auto simp add: equivp_def expand_fun_eq)
   772 
   773   quotient_definition
   774     "0::int" is "(0::nat, 0::nat)"
   775 
   776 The method "lifting" can be used to lift of theorems from the
   777 underlying "raw" type to the quotient type.  The example
   778 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   779 construction and provides a reasoning infrastructure for finite sets.
   780 
   781 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   782 clash with new theory Quotient in Main HOL.
   783 
   784 * Moved the SMT binding into the main HOL session, eliminating
   785 separate HOL-SMT session.
   786 
   787 * List membership infix mem operation is only an input abbreviation.
   788 INCOMPATIBILITY.
   789 
   790 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   791 for future developements; former Library/Word.thy is still present in
   792 the AFP entry RSAPPS.
   793 
   794 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   795 longer shadowed.  INCOMPATIBILITY.
   796 
   797 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   798 INCOMPATIBILITY.
   799 
   800 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   801 INCOMPATIBILITY.
   802 
   803 * Dropped normalizing_semiring etc; use the facts in semiring classes
   804 instead.  INCOMPATIBILITY.
   805 
   806 * Dropped several real-specific versions of lemmas about floor and
   807 ceiling; use the generic lemmas from theory "Archimedean_Field"
   808 instead.  INCOMPATIBILITY.
   809 
   810   floor_number_of_eq         ~> floor_number_of
   811   le_floor_eq_number_of      ~> number_of_le_floor
   812   le_floor_eq_zero           ~> zero_le_floor
   813   le_floor_eq_one            ~> one_le_floor
   814   floor_less_eq_number_of    ~> floor_less_number_of
   815   floor_less_eq_zero         ~> floor_less_zero
   816   floor_less_eq_one          ~> floor_less_one
   817   less_floor_eq_number_of    ~> number_of_less_floor
   818   less_floor_eq_zero         ~> zero_less_floor
   819   less_floor_eq_one          ~> one_less_floor
   820   floor_le_eq_number_of      ~> floor_le_number_of
   821   floor_le_eq_zero           ~> floor_le_zero
   822   floor_le_eq_one            ~> floor_le_one
   823   floor_subtract_number_of   ~> floor_diff_number_of
   824   floor_subtract_one         ~> floor_diff_one
   825   ceiling_number_of_eq       ~> ceiling_number_of
   826   ceiling_le_eq_number_of    ~> ceiling_le_number_of
   827   ceiling_le_zero_eq         ~> ceiling_le_zero
   828   ceiling_le_eq_one          ~> ceiling_le_one
   829   less_ceiling_eq_number_of  ~> number_of_less_ceiling
   830   less_ceiling_eq_zero       ~> zero_less_ceiling
   831   less_ceiling_eq_one        ~> one_less_ceiling
   832   ceiling_less_eq_number_of  ~> ceiling_less_number_of
   833   ceiling_less_eq_zero       ~> ceiling_less_zero
   834   ceiling_less_eq_one        ~> ceiling_less_one
   835   le_ceiling_eq_number_of    ~> number_of_le_ceiling
   836   le_ceiling_eq_zero         ~> zero_le_ceiling
   837   le_ceiling_eq_one          ~> one_le_ceiling
   838   ceiling_subtract_number_of ~> ceiling_diff_number_of
   839   ceiling_subtract_one       ~> ceiling_diff_one
   840 
   841 * Theory "Finite_Set": various folding_XXX locales facilitate the
   842 application of the various fold combinators on finite sets.
   843 
   844 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
   845 provides abstract red-black tree type which is backed by "RBT_Impl" as
   846 implementation.  INCOMPATIBILTY.
   847 
   848 * Theory Library/Coinductive_List has been removed -- superseded by
   849 AFP/thys/Coinductive.
   850 
   851 * Theory PReal, including the type "preal" and related operations, has
   852 been removed.  INCOMPATIBILITY.
   853 
   854 * Real: new development using Cauchy Sequences.
   855 
   856 * Split off theory "Big_Operators" containing setsum, setprod,
   857 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
   858 
   859 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
   860 "Int" etc.  INCOMPATIBILITY.
   861 
   862 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
   863 
   864 * New set of rules "ac_simps" provides combined assoc / commute
   865 rewrites for all interpretations of the appropriate generic locales.
   866 
   867 * Renamed theory "OrderedGroup" to "Groups" and split theory
   868 "Ring_and_Field" into theories "Rings" and "Fields"; for more
   869 appropriate and more consistent names suitable for name prefixes
   870 within the HOL theories.  INCOMPATIBILITY.
   871 
   872 * Some generic constants have been put to appropriate theories:
   873   - less_eq, less: Orderings
   874   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
   875   - inverse, divide: Rings
   876 INCOMPATIBILITY.
   877 
   878 * More consistent naming of type classes involving orderings (and
   879 lattices):
   880 
   881     lower_semilattice                   ~> semilattice_inf
   882     upper_semilattice                   ~> semilattice_sup
   883 
   884     dense_linear_order                  ~> dense_linorder
   885 
   886     pordered_ab_group_add               ~> ordered_ab_group_add
   887     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
   888     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
   889     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
   890     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
   891     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
   892     pordered_cancel_semiring            ~> ordered_cancel_semiring
   893     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
   894     pordered_comm_ring                  ~> ordered_comm_ring
   895     pordered_comm_semiring              ~> ordered_comm_semiring
   896     pordered_ring                       ~> ordered_ring
   897     pordered_ring_abs                   ~> ordered_ring_abs
   898     pordered_semiring                   ~> ordered_semiring
   899 
   900     ordered_ab_group_add                ~> linordered_ab_group_add
   901     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
   902     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
   903     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
   904     ordered_field                       ~> linordered_field
   905     ordered_field_no_lb                 ~> linordered_field_no_lb
   906     ordered_field_no_ub                 ~> linordered_field_no_ub
   907     ordered_field_dense_linear_order    ~> dense_linordered_field
   908     ordered_idom                        ~> linordered_idom
   909     ordered_ring                        ~> linordered_ring
   910     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
   911     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
   912     ordered_ring_strict                 ~> linordered_ring_strict
   913     ordered_semidom                     ~> linordered_semidom
   914     ordered_semiring                    ~> linordered_semiring
   915     ordered_semiring_1                  ~> linordered_semiring_1
   916     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
   917     ordered_semiring_strict             ~> linordered_semiring_strict
   918 
   919   The following slightly odd type classes have been moved to a
   920   separate theory Library/Lattice_Algebras:
   921 
   922     lordered_ab_group_add               ~> lattice_ab_group_add
   923     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
   924     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
   925     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
   926     lordered_ring                       ~> lattice_ring
   927 
   928 INCOMPATIBILITY.
   929 
   930 * Refined field classes:
   931   - classes division_ring_inverse_zero, field_inverse_zero,
   932     linordered_field_inverse_zero include rule inverse 0 = 0 --
   933     subsumes former division_by_zero class;
   934   - numerous lemmas have been ported from field to division_ring.
   935 INCOMPATIBILITY.
   936 
   937 * Refined algebra theorem collections:
   938   - dropped theorem group group_simps, use algebra_simps instead;
   939   - dropped theorem group ring_simps, use field_simps instead;
   940   - proper theorem collection field_simps subsumes former theorem
   941     groups field_eq_simps and field_simps;
   942   - dropped lemma eq_minus_self_iff which is a duplicate for
   943     equal_neg_zero.
   944 INCOMPATIBILITY.
   945 
   946 * Theory Finite_Set and List: some lemmas have been generalized from
   947 sets to lattices:
   948 
   949   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
   950   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
   951   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
   952   union_Union_fold_union        ~> sup_Sup_fold_sup
   953   Inter_fold_inter              ~> Inf_fold_inf
   954   Union_fold_union              ~> Sup_fold_sup
   955   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
   956   union_UNION_fold_union        ~> sup_SUPR_fold_sup
   957   INTER_fold_inter              ~> INFI_fold_inf
   958   UNION_fold_union              ~> SUPR_fold_sup
   959 
   960 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
   961 replaced by the more convenient lemmas Inf_empty and Sup_empty.
   962 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
   963 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
   964 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
   965 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
   966 
   967 * Reorganized theory Multiset: swapped notation of pointwise and
   968 multiset order:
   969 
   970   - pointwise ordering is instance of class order with standard syntax
   971     <= and <;
   972   - multiset ordering has syntax <=# and <#; partial order properties
   973     are provided by means of interpretation with prefix
   974     multiset_order;
   975   - less duplication, less historical organization of sections,
   976     conversion from associations lists to multisets, rudimentary code
   977     generation;
   978   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
   979     if needed.
   980 
   981 Renamed:
   982 
   983   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
   984   multi_count_ext  ~>  multiset_ext
   985   diff_union_inverse2  ~>  diff_union_cancelR
   986 
   987 INCOMPATIBILITY.
   988 
   989 * Theory Permutation: replaced local "remove" by List.remove1.
   990 
   991 * Code generation: ML and OCaml code is decorated with signatures.
   992 
   993 * Theory List: added transpose.
   994 
   995 * Library/Nat_Bijection.thy is a collection of bijective functions
   996 between nat and other types, which supersedes the older libraries
   997 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
   998 
   999   Constants:
  1000   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1001   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1002   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1003   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1004   Countable.pair_encode           ~> prod_encode
  1005   NatIso.prod2nat                 ~> prod_encode
  1006   NatIso.nat2prod                 ~> prod_decode
  1007   NatIso.sum2nat                  ~> sum_encode
  1008   NatIso.nat2sum                  ~> sum_decode
  1009   NatIso.list2nat                 ~> list_encode
  1010   NatIso.nat2list                 ~> list_decode
  1011   NatIso.set2nat                  ~> set_encode
  1012   NatIso.nat2set                  ~> set_decode
  1013 
  1014   Lemmas:
  1015   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1016   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1017   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1018   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1019   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1020   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1021   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1022   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1023   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1024   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1025   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1026   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1027   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1028 
  1029 * Sledgehammer:
  1030   - Renamed ATP commands:
  1031     atp_info     ~> sledgehammer running_atps
  1032     atp_kill     ~> sledgehammer kill_atps
  1033     atp_messages ~> sledgehammer messages
  1034     atp_minimize ~> sledgehammer minimize
  1035     print_atps   ~> sledgehammer available_atps
  1036     INCOMPATIBILITY.
  1037   - Added user's manual ("isabelle doc sledgehammer").
  1038   - Added option syntax and "sledgehammer_params" to customize
  1039     Sledgehammer's behavior.  See the manual for details.
  1040   - Modified the Isar proof reconstruction code so that it produces
  1041     direct proofs rather than proofs by contradiction.  (This feature
  1042     is still experimental.)
  1043   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1044     full-typed mode.
  1045   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1046 
  1047 * Nitpick:
  1048   - Added and implemented "binary_ints" and "bits" options.
  1049   - Added "std" option and implemented support for nonstandard models.
  1050   - Added and implemented "finitize" option to improve the precision
  1051     of infinite datatypes based on a monotonicity analysis.
  1052   - Added support for quotient types.
  1053   - Added support for "specification" and "ax_specification"
  1054     constructs.
  1055   - Added support for local definitions (for "function" and
  1056     "termination" proofs).
  1057   - Added support for term postprocessors.
  1058   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1059   - Improved efficiency of "destroy_constrs" optimization.
  1060   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1061     record getters.
  1062   - Fixed soundness bug related to higher-order constructors.
  1063   - Fixed soundness bug when "full_descrs" is enabled.
  1064   - Improved precision of set constructs.
  1065   - Added "atoms" option.
  1066   - Added cache to speed up repeated Kodkod invocations on the same
  1067     problems.
  1068   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1069     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1070     "SAT4J_Light".  INCOMPATIBILITY.
  1071   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1072     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1073   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1074 
  1075 * Method "induct" now takes instantiations of the form t, where t is not
  1076   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1077   If this is not intended, t has to be enclosed in parentheses.
  1078   By default, the equalities generated by definitional instantiations
  1079   are pre-simplified, which may cause parameters of inductive cases
  1080   to disappear, or may even delete some of the inductive cases.
  1081   Use "induct (no_simp)" instead of "induct" to restore the old
  1082   behaviour. The (no_simp) option is also understood by the "cases"
  1083   and "nominal_induct" methods, which now perform pre-simplification, too.
  1084   INCOMPATIBILITY.
  1085 
  1086 
  1087 *** HOLCF ***
  1088 
  1089 * Variable names in lemmas generated by the domain package have
  1090 changed; the naming scheme is now consistent with the HOL datatype
  1091 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1092 
  1093 * The domain package no longer defines the function "foo_copy" for
  1094 recursive domain "foo".  The reach lemma is now stated directly in
  1095 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1096 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1097 
  1098 * Most definedness lemmas generated by the domain package (previously
  1099 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1100 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1101 Proofs that used definedness lemmas as intro rules may break,
  1102 potential INCOMPATIBILITY.
  1103 
  1104 * Induction and casedist rules generated by the domain package now
  1105 declare proper case_names (one called "bottom", and one named for each
  1106 constructor).  INCOMPATIBILITY.
  1107 
  1108 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1109 rules are generated for each domain, INCOMPATIBILITY.
  1110 
  1111   foo_bar.reach       ~> foo.reach  bar.reach
  1112   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1113 
  1114 * Some lemmas generated by the domain package have been renamed for
  1115 consistency with the datatype package, INCOMPATIBILITY.
  1116 
  1117   foo.ind        ~> foo.induct
  1118   foo.finite_ind ~> foo.finite_induct
  1119   foo.coind      ~> foo.coinduct
  1120   foo.casedist   ~> foo.exhaust
  1121   foo.exhaust    ~> foo.nchotomy
  1122 
  1123 * For consistency with other definition packages, the fixrec package
  1124 now generates qualified theorem names, INCOMPATIBILITY.
  1125 
  1126   foo_simps  ~> foo.simps
  1127   foo_unfold ~> foo.unfold
  1128   foo_induct ~> foo.induct
  1129 
  1130 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1131 method and internal fixrec proofs now use the default simpset instead.
  1132 INCOMPATIBILITY.
  1133 
  1134 * The "contlub" predicate has been removed.  Proof scripts should use
  1135 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1136 
  1137 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1138 
  1139 * The constants cpair, cfst, and csnd have been removed in favor of
  1140 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1141 
  1142 
  1143 *** ML ***
  1144 
  1145 * Antiquotations for basic formal entities:
  1146 
  1147     @{class NAME}         -- type class
  1148     @{class_syntax NAME}  -- syntax representation of the above
  1149 
  1150     @{type_name NAME}     -- logical type
  1151     @{type_abbrev NAME}   -- type abbreviation
  1152     @{nonterminal NAME}   -- type of concrete syntactic category
  1153     @{type_syntax NAME}   -- syntax representation of any of the above
  1154 
  1155     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1156     @{const_abbrev NAME}  -- abbreviated constant
  1157     @{const_syntax NAME}  -- syntax representation of any of the above
  1158 
  1159 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1160 syntax constant (cf. 'syntax' command).
  1161 
  1162 * Antiquotation @{make_string} inlines a function to print arbitrary
  1163 values similar to the ML toplevel.  The result is compiler dependent
  1164 and may fall back on "?" in certain situations.
  1165 
  1166 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1167 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1168 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1169 not work with the asynchronous Isar document model.
  1170 
  1171 * Configuration options now admit dynamic default values, depending on
  1172 the context or even global references.
  1173 
  1174 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1175 uses an efficient external library if available (for Poly/ML).
  1176 
  1177 * Renamed some important ML structures, while keeping the old names
  1178 for some time as aliases within the structure Legacy:
  1179 
  1180   OuterKeyword  ~>  Keyword
  1181   OuterLex      ~>  Token
  1182   OuterParse    ~>  Parse
  1183   OuterSyntax   ~>  Outer_Syntax
  1184   PrintMode     ~>  Print_Mode
  1185   SpecParse     ~>  Parse_Spec
  1186   ThyInfo       ~>  Thy_Info
  1187   ThyLoad       ~>  Thy_Load
  1188   ThyOutput     ~>  Thy_Output
  1189   TypeInfer     ~>  Type_Infer
  1190 
  1191 Note that "open Legacy" simplifies porting of sources, but forgetting
  1192 to remove it again will complicate porting again in the future.
  1193 
  1194 * Most operations that refer to a global context are named
  1195 accordingly, e.g. Simplifier.global_context or
  1196 ProofContext.init_global.  There are some situations where a global
  1197 context actually works, but under normal circumstances one needs to
  1198 pass the proper local context through the code!
  1199 
  1200 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1201 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1202 Pretty.pp argument to merge, which is absent in the standard
  1203 Theory_Data version.
  1204 
  1205 * Sorts.certify_sort and derived "cert" operations for types and terms
  1206 no longer minimize sorts.  Thus certification at the boundary of the
  1207 inference kernel becomes invariant under addition of class relations,
  1208 which is an important monotonicity principle.  Sorts are now minimized
  1209 in the syntax layer only, at the boundary between the end-user and the
  1210 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1211 explicitly in rare situations.
  1212 
  1213 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1214 emphasize that this is in no way a standard operation.
  1215 INCOMPATIBILITY.
  1216 
  1217 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1218 usual for resolution.  Rare INCOMPATIBILITY.
  1219 
  1220 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1221 to emphasize that these only work in a global situation (which is
  1222 quite rare).
  1223 
  1224 * Curried take and drop in library.ML; negative length is interpreted
  1225 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1226 
  1227 * Proof terms: type substitutions on proof constants now use canonical
  1228 order of type variables.  INCOMPATIBILITY for tools working with proof
  1229 terms.
  1230 
  1231 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1232 may no longer carry premises.  User-level specifications are
  1233 transformed accordingly by Thm.add_axiom/add_def.
  1234 
  1235 
  1236 *** System ***
  1237 
  1238 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1239 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1240 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1241 
  1242 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1243 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1244 respectively.
  1245 
  1246 * Old lib/scripts/polyml-platform is superseded by the
  1247 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1248 variant, even on a 64 bit machine.  The following example setting
  1249 prefers 64 bit if available:
  1250 
  1251   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1252 
  1253 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1254 Isabelle/Scala layer for advanced prover interaction and integration.
  1255 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1256 component.
  1257 
  1258 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1259 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1260 similar to the default assignment of the document preparation system
  1261 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1262 provides some operations for direct access to the font without asking
  1263 the user for manual installation.
  1264 
  1265 
  1266 
  1267 New in Isabelle2009-1 (December 2009)
  1268 -------------------------------------
  1269 
  1270 *** General ***
  1271 
  1272 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1273 one backslash should be used, even in ML sources.
  1274 
  1275 
  1276 *** Pure ***
  1277 
  1278 * Locale interpretation propagates mixins along the locale hierarchy.
  1279 The currently only available mixins are the equations used to map
  1280 local definitions to terms of the target domain of an interpretation.
  1281 
  1282 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1283 loc" to print all interpretations of locale "loc" in the theory.
  1284 Interpretations in proofs are not shown.
  1285 
  1286 * Thoroughly revised locales tutorial.  New section on conditional
  1287 interpretation.
  1288 
  1289 * On instantiation of classes, remaining undefined class parameters
  1290 are formally declared.  INCOMPATIBILITY.
  1291 
  1292 
  1293 *** Document preparation ***
  1294 
  1295 * New generalized style concept for printing terms: @{foo (style) ...}
  1296 instead of @{foo_style style ...}  (old form is still retained for
  1297 backward compatibility).  Styles can be also applied for
  1298 antiquotations prop, term_type and typeof.
  1299 
  1300 
  1301 *** HOL ***
  1302 
  1303 * New proof method "smt" for a combination of first-order logic with
  1304 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1305 fixed-size bitvectors; there is also basic support for higher-order
  1306 features (esp. lambda abstractions).  It is an incomplete decision
  1307 procedure based on external SMT solvers using the oracle mechanism;
  1308 for the SMT solver Z3, this method is proof-producing.  Certificates
  1309 are provided to avoid calling the external solvers solely for
  1310 re-checking proofs.  Due to a remote SMT service there is no need for
  1311 installing SMT solvers locally.  See src/HOL/SMT.
  1312 
  1313 * New commands to load and prove verification conditions generated by
  1314 the Boogie program verifier or derived systems (e.g. the Verifying C
  1315 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1316 
  1317 * New counterexample generator tool 'nitpick' based on the Kodkod
  1318 relational model finder.  See src/HOL/Tools/Nitpick and
  1319 src/HOL/Nitpick_Examples.
  1320 
  1321 * New commands 'code_pred' and 'values' to invoke the predicate
  1322 compiler and to enumerate values of inductive predicates.
  1323 
  1324 * A tabled implementation of the reflexive transitive closure.
  1325 
  1326 * New implementation of quickcheck uses generic code generator;
  1327 default generators are provided for all suitable HOL types, records
  1328 and datatypes.  Old quickcheck can be re-activated importing theory
  1329 Library/SML_Quickcheck.
  1330 
  1331 * New testing tool Mirabelle for automated proof tools.  Applies
  1332 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1333 every proof step in a theory.  To be used in batch mode via the
  1334 "mirabelle" utility.
  1335 
  1336 * New proof method "sos" (sum of squares) for nonlinear real
  1337 arithmetic (originally due to John Harison). It requires theory
  1338 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1339 works well in practice on quantifier-free real arithmetic with +, -,
  1340 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1341 inequalities between polynomials.  It makes use of external
  1342 semidefinite programming solvers.  Method "sos" generates a
  1343 certificate that can be pasted into the proof thus avoiding the need
  1344 to call an external tool every time the proof is checked.  See
  1345 src/HOL/Library/Sum_Of_Squares.
  1346 
  1347 * New method "linarith" invokes existing linear arithmetic decision
  1348 procedure only.
  1349 
  1350 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1351 
  1352 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1353 Causes full type information to be output to the ATPs.  This slows
  1354 ATPs down considerably but eliminates a source of unsound "proofs"
  1355 that fail later.
  1356 
  1357 * New method "metisFT": A version of metis that uses full type
  1358 information in order to avoid failures of proof reconstruction.
  1359 
  1360 * New evaluator "approximate" approximates an real valued term using
  1361 the same method as the approximation method.
  1362 
  1363 * Method "approximate" now supports arithmetic expressions as
  1364 boundaries of intervals and implements interval splitting and Taylor
  1365 series expansion.
  1366 
  1367 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1368 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1369 
  1370 * New theory SupInf of the supremum and infimum operators for sets of
  1371 reals.
  1372 
  1373 * New theory Probability, which contains a development of measure
  1374 theory, eventually leading to Lebesgue integration and probability.
  1375 
  1376 * Extended Multivariate Analysis to include derivation and Brouwer's
  1377 fixpoint theorem.
  1378 
  1379 * Reorganization of number theory, INCOMPATIBILITY:
  1380   - new number theory development for nat and int, in theories Divides
  1381     and GCD as well as in new session Number_Theory
  1382   - some constants and facts now suffixed with _nat and _int
  1383     accordingly
  1384   - former session NumberTheory now named Old_Number_Theory, including
  1385     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1386   - moved theory Pocklington from src/HOL/Library to
  1387     src/HOL/Old_Number_Theory
  1388 
  1389 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1390 lcm of finite and infinite sets. It is shown that they form a complete
  1391 lattice.
  1392 
  1393 * Class semiring_div requires superclass no_zero_divisors and proof of
  1394 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1395 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1396 generalized to class semiring_div, subsuming former theorems
  1397 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1398 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1399 INCOMPATIBILITY.
  1400 
  1401 * Refinements to lattice classes and sets:
  1402   - less default intro/elim rules in locale variant, more default
  1403     intro/elim rules in class variant: more uniformity
  1404   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1405     le_inf_iff
  1406   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1407     sup_aci)
  1408   - renamed ACI to inf_sup_aci
  1409   - new class "boolean_algebra"
  1410   - class "complete_lattice" moved to separate theory
  1411     "Complete_Lattice"; corresponding constants (and abbreviations)
  1412     renamed and with authentic syntax:
  1413     Set.Inf ~>    Complete_Lattice.Inf
  1414     Set.Sup ~>    Complete_Lattice.Sup
  1415     Set.INFI ~>   Complete_Lattice.INFI
  1416     Set.SUPR ~>   Complete_Lattice.SUPR
  1417     Set.Inter ~>  Complete_Lattice.Inter
  1418     Set.Union ~>  Complete_Lattice.Union
  1419     Set.INTER ~>  Complete_Lattice.INTER
  1420     Set.UNION ~>  Complete_Lattice.UNION
  1421   - authentic syntax for
  1422     Set.Pow
  1423     Set.image
  1424   - mere abbreviations:
  1425     Set.empty               (for bot)
  1426     Set.UNIV                (for top)
  1427     Set.inter               (for inf, formerly Set.Int)
  1428     Set.union               (for sup, formerly Set.Un)
  1429     Complete_Lattice.Inter  (for Inf)
  1430     Complete_Lattice.Union  (for Sup)
  1431     Complete_Lattice.INTER  (for INFI)
  1432     Complete_Lattice.UNION  (for SUPR)
  1433   - object-logic definitions as far as appropriate
  1434 
  1435 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1436 Un_subset_iff are explicitly deleted as default simp rules; then also
  1437 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1438 deleted to achieve the desired effect.
  1439 
  1440 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1441 rules by default any longer; the same applies to min_max.inf_absorb1
  1442 etc.  INCOMPATIBILITY.
  1443 
  1444 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1445 pred_set_conv by default.  INCOMPATIBILITY.
  1446 
  1447 * Power operations on relations and functions are now one dedicated
  1448 constant "compow" with infix syntax "^^".  Power operation on
  1449 multiplicative monoids retains syntax "^" and is now defined generic
  1450 in class power.  INCOMPATIBILITY.
  1451 
  1452 * Relation composition "R O S" now has a more standard argument order:
  1453 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1454 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1455 break, since the O_assoc rule was not rewritten like this.  Fix using
  1456 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1457 
  1458 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1459 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1460 INCOMPATIBILITY.
  1461 
  1462 * Most rules produced by inductive and datatype package have mandatory
  1463 prefixes.  INCOMPATIBILITY.
  1464 
  1465 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1466 the attribute of the same name.  Each of the theorems in the list
  1467 DERIV_intros assumes composition with an additional function and
  1468 matches a variable to the derivative, which has to be solved by the
  1469 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1470 of most elementary terms.  Former Maclauren.DERIV_tac and
  1471 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1472 INCOMPATIBILITY.
  1473 
  1474 * Code generator attributes follow the usual underscore convention:
  1475     code_unfold     replaces    code unfold
  1476     code_post       replaces    code post
  1477     etc.
  1478   INCOMPATIBILITY.
  1479 
  1480 * Renamed methods:
  1481     sizechange -> size_change
  1482     induct_scheme -> induction_schema
  1483   INCOMPATIBILITY.
  1484 
  1485 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1486 INCOMPATIBILITY, use "undefined" directly.
  1487 
  1488 * Renamed theorems:
  1489     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1490     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1491     Suc_plus1 -> Suc_eq_plus1
  1492     *anti_sym -> *antisym*
  1493     vector_less_eq_def -> vector_le_def
  1494   INCOMPATIBILITY.
  1495 
  1496 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1497 INCOMPATIBILITY.
  1498 
  1499 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1500 INCOMPATIBILITY.
  1501 
  1502 
  1503 *** HOLCF ***
  1504 
  1505 * Theory Representable defines a class "rep" of domains that are
  1506 representable (via an ep-pair) in the universal domain type "udom".
  1507 Instances are provided for all type constructors defined in HOLCF.
  1508 
  1509 * The 'new_domain' command is a purely definitional version of the
  1510 domain package, for representable domains.  Syntax is identical to the
  1511 old domain package.  The 'new_domain' package also supports indirect
  1512 recursion using previously-defined type constructors.  See
  1513 src/HOLCF/ex/New_Domain.thy for examples.
  1514 
  1515 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1516 on the left-hand side of an equation, and then performs
  1517 simplification.  Rewriting is done using rules declared with the
  1518 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1519 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1520 
  1521 * The pattern-match compiler in 'fixrec' can now handle constructors
  1522 with HOL function types.  Pattern-match combinators for the Pair
  1523 constructor are pre-configured.
  1524 
  1525 * The 'fixrec' package now produces better fixed-point induction rules
  1526 for mutually-recursive definitions:  Induction rules have conclusions
  1527 of the form "P foo bar" instead of "P <foo, bar>".
  1528 
  1529 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1530 been renamed to "below".  The name "below" now replaces "less" in many
  1531 theorem names.  (Legacy theorem names using "less" are still supported
  1532 as well.)
  1533 
  1534 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1535 patterns can be used to generate strictness rules, or to make
  1536 functions more strict (much like the bang-patterns supported by the
  1537 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1538 examples.
  1539 
  1540 
  1541 *** ML ***
  1542 
  1543 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1544 errors and run-time exceptions, including detailed source positions.
  1545 
  1546 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1547 identified entries, with some additional information such as source
  1548 position, logical grouping etc.
  1549 
  1550 * Theory and context data is now introduced by the simplified and
  1551 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1552 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1553 copy operation) is still available for some time.
  1554 
  1555 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1556 provides a high-level programming interface to synchronized state
  1557 variables with atomic update.  This works via pure function
  1558 application within a critical section -- its runtime should be as
  1559 short as possible; beware of deadlocks if critical code is nested,
  1560 either directly or indirectly via other synchronized variables!
  1561 
  1562 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1563 wraps raw ML references, explicitly indicating their non-thread-safe
  1564 behaviour.  The Isar toplevel keeps this structure open, to
  1565 accommodate Proof General as well as quick and dirty interactive
  1566 experiments with references.
  1567 
  1568 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1569 parallel tactical reasoning.
  1570 
  1571 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1572 are similar to SUBPROOF, but are slightly more flexible: only the
  1573 specified parts of the subgoal are imported into the context, and the
  1574 body tactic may introduce new subgoals and schematic variables.
  1575 
  1576 * Old tactical METAHYPS, which does not observe the proof context, has
  1577 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1578 or Subgoal.FOCUS etc.
  1579 
  1580 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1581 functors have their own ML name space there is no point to mark them
  1582 separately.)  Minor INCOMPATIBILITY.
  1583 
  1584 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1585 
  1586 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1587 INCOMPATIBILITY.
  1588 
  1589 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1590 mode, which avoids critical setmp.
  1591 
  1592 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1593 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1594 Attrib/Method.setup introduced in Isabelle2009.
  1595 
  1596 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1597 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1598 last resort.  INCOMPATIBILITY.
  1599 
  1600 * Display.pretty_thm now requires a proper context (cf. former
  1601 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1602 or even Display.pretty_thm_without_context as last resort.
  1603 INCOMPATIBILITY.
  1604 
  1605 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1606 Syntax.pretty_typ/term directly, preferably with proper context
  1607 instead of global theory.
  1608 
  1609 
  1610 *** System ***
  1611 
  1612 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1613 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1614 usedir option -q.
  1615 
  1616 * Support for additional "Isabelle components" via etc/components, see
  1617 also the system manual.
  1618 
  1619 * The isabelle makeall tool now operates on all components with
  1620 IsaMakefile, not just hardwired "logics".
  1621 
  1622 * Removed "compress" option from isabelle-process and isabelle usedir;
  1623 this is always enabled.
  1624 
  1625 * Discontinued support for Poly/ML 4.x versions.
  1626 
  1627 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1628 on a given logic image.  This requires the lighttpd webserver and is
  1629 currently supported on Linux only.
  1630 
  1631 
  1632 
  1633 New in Isabelle2009 (April 2009)
  1634 --------------------------------
  1635 
  1636 *** General ***
  1637 
  1638 * Simplified main Isabelle executables, with less surprises on
  1639 case-insensitive file-systems (such as Mac OS).
  1640 
  1641   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1642     "isatool."
  1643 
  1644   - The former "isabelle" alias for "isabelle-process" has been
  1645     removed (should rarely occur to regular users).
  1646 
  1647   - The former "isabelle-interface" and its alias "Isabelle" have been
  1648     removed (interfaces are now regular Isabelle tools).
  1649 
  1650 Within scripts and make files, the Isabelle environment variables
  1651 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1652 respectively.  (The latter are still available as legacy feature.)
  1653 
  1654 The old isabelle-interface wrapper could react in confusing ways if
  1655 the interface was uninstalled or changed otherwise.  Individual
  1656 interface tool configuration is now more explicit, see also the
  1657 Isabelle system manual.  In particular, Proof General is now available
  1658 via "isabelle emacs".
  1659 
  1660 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1661 purge installed copies of Isabelle executables and re-run "isabelle
  1662 install -p ...", or use symlinks.
  1663 
  1664 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1665 old ~/isabelle, which was slightly non-standard and apt to cause
  1666 surprises on case-insensitive file-systems (such as Mac OS).
  1667 
  1668 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1669 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1670 care is required when using older releases of Isabelle.  Note that
  1671 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1672 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1673 
  1674 * Proofs of fully specified statements are run in parallel on
  1675 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1676 a regular 4-core machine, if the initial heap space is made reasonably
  1677 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1678 
  1679 * The main reference manuals ("isar-ref", "implementation", and
  1680 "system") have been updated and extended.  Formally checked references
  1681 as hyperlinks are now available uniformly.
  1682 
  1683 
  1684 *** Pure ***
  1685 
  1686 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1687 respects.  The most important changes are listed below.  See the
  1688 Tutorial on Locales ("locales" manual) for details.
  1689 
  1690 - In locale expressions, instantiation replaces renaming.  Parameters
  1691 must be declared in a for clause.  To aid compatibility with previous
  1692 parameter inheritance, in locale declarations, parameters that are not
  1693 'touched' (instantiation position "_" or omitted) are implicitly added
  1694 with their syntax at the beginning of the for clause.
  1695 
  1696 - Syntax from abbreviations and definitions in locales is available in
  1697 locale expressions and context elements.  The latter is particularly
  1698 useful in locale declarations.
  1699 
  1700 - More flexible mechanisms to qualify names generated by locale
  1701 expressions.  Qualifiers (prefixes) may be specified in locale
  1702 expressions, and can be marked as mandatory (syntax: "name!:") or
  1703 optional (syntax "name?:").  The default depends for plain "name:"
  1704 depends on the situation where a locale expression is used: in
  1705 commands 'locale' and 'sublocale' prefixes are optional, in
  1706 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1707 implicit qualifiers derived from the parameter names of a locale are
  1708 no longer generated.
  1709 
  1710 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1711 instantiation clause in "interpretation" and "interpret" (square
  1712 brackets) is no longer available.  Use locale expressions.
  1713 
  1714 - When converting proof scripts, mandatory qualifiers in
  1715 'interpretation' and 'interpret' should be retained by default, even
  1716 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1717 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1718 in locale expressions range over a single locale instance only.
  1719 
  1720 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1721 In existing theorem specifications replace the includes element by the
  1722 respective context elements of the included locale, omitting those
  1723 that are already present in the theorem specification.  Multiple
  1724 assume elements of a locale should be replaced by a single one
  1725 involving the locale predicate.  In the proof body, declarations (most
  1726 notably theorems) may be regained by interpreting the respective
  1727 locales in the proof context as required (command "interpret").
  1728 
  1729 If using "includes" in replacement of a target solely because the
  1730 parameter types in the theorem are not as general as in the target,
  1731 consider declaring a new locale with additional type constraints on
  1732 the parameters (context element "constrains").
  1733 
  1734 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1735 
  1736 - Locale interpretation commands no longer attempt to simplify goal.
  1737 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1738 methods intro_locales and unfold_locales to clarify.
  1739 
  1740 - Locale interpretation commands no longer accept interpretation
  1741 attributes.  INCOMPATIBILITY.
  1742 
  1743 * Class declaration: so-called "base sort" must not be given in import
  1744 list any longer, but is inferred from the specification.  Particularly
  1745 in HOL, write
  1746 
  1747     class foo = ...
  1748 
  1749 instead of
  1750 
  1751     class foo = type + ...
  1752 
  1753 * Class target: global versions of theorems stemming do not carry a
  1754 parameter prefix any longer.  INCOMPATIBILITY.
  1755 
  1756 * Class 'instance' command no longer accepts attached definitions.
  1757 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1758 
  1759 * Recovered hiding of consts, which was accidentally broken in
  1760 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1761 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1762 
  1763 * Slightly more coherent Pure syntax, with updated documentation in
  1764 isar-ref manual.  Removed locales meta_term_syntax and
  1765 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1766 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1767 directly in regular applications.
  1768 
  1769 * There is a new syntactic category "float_const" for signed decimal
  1770 fractions (e.g. 123.45 or -123.45).
  1771 
  1772 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1773 interface with 'setup' command instead.
  1774 
  1775 * Command 'local_setup' is similar to 'setup', but operates on a local
  1776 theory context.
  1777 
  1778 * The 'axiomatization' command now only works within a global theory
  1779 context.  INCOMPATIBILITY.
  1780 
  1781 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1782 hypotheses.  Sorts required in the course of reasoning need to be
  1783 covered by the constraints in the initial statement, completed by the
  1784 type instance information of the background theory.  Non-trivial sort
  1785 hypotheses, which rarely occur in practice, may be specified via
  1786 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1787 
  1788   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1789 
  1790 The result contains an implicit sort hypotheses as before --
  1791 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1792 normalization.
  1793 
  1794 * Generalized Isar history, with support for linear undo, direct state
  1795 addressing etc.
  1796 
  1797 * Changed defaults for unify configuration options:
  1798 
  1799   unify_trace_bound = 50 (formerly 25)
  1800   unify_search_bound = 60 (formerly 30)
  1801 
  1802 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1803 
  1804   a) On theory merge, the last set of code equations for a particular
  1805      constant is taken (in accordance with the policy applied by other
  1806      parts of the code generator framework).
  1807 
  1808   b) Code equations stemming from explicit declarations (e.g. code
  1809      attribute) gain priority over default code equations stemming
  1810      from definition, primrec, fun etc.
  1811 
  1812 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  1813 
  1814 * Unified theorem tables for both code generators.  Thus [code
  1815 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  1816 
  1817 * Command 'find_consts' searches for constants based on type and name
  1818 patterns, e.g.
  1819 
  1820     find_consts "_ => bool"
  1821 
  1822 By default, matching is against subtypes, but it may be restricted to
  1823 the whole type.  Searching by name is possible.  Multiple queries are
  1824 conjunctive and queries may be negated by prefixing them with a
  1825 hyphen:
  1826 
  1827     find_consts strict: "_ => bool" name: "Int" -"int => int"
  1828 
  1829 * New 'find_theorems' criterion "solves" matches theorems that
  1830 directly solve the current goal (modulo higher-order unification).
  1831 
  1832 * Auto solve feature for main theorem statements: whenever a new goal
  1833 is stated, "find_theorems solves" is called; any theorems that could
  1834 solve the lemma directly are listed as part of the goal state.
  1835 Cf. associated options in Proof General Isabelle settings menu,
  1836 enabled by default, with reasonable timeout for pathological cases of
  1837 higher-order unification.
  1838 
  1839 
  1840 *** Document preparation ***
  1841 
  1842 * Antiquotation @{lemma} now imitates a regular terminal proof,
  1843 demanding keyword 'by' and supporting the full method expression
  1844 syntax just like the Isar command 'by'.
  1845 
  1846 
  1847 *** HOL ***
  1848 
  1849 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  1850 points Main and Complex_Main remain as before.
  1851 
  1852 * Logic image HOL-Plain provides a minimal HOL with the most important
  1853 tools available (inductive, datatype, primrec, ...).  This facilitates
  1854 experimentation and tool development.  Note that user applications
  1855 (and library theories) should never refer to anything below theory
  1856 Main, as before.
  1857 
  1858 * Logic image HOL-Main stops at theory Main, and thus facilitates
  1859 experimentation due to shorter build times.
  1860 
  1861 * Logic image HOL-NSA contains theories of nonstandard analysis which
  1862 were previously part of former HOL-Complex.  Entry point Hyperreal
  1863 remains valid, but theories formerly using Complex_Main should now use
  1864 new entry point Hypercomplex.
  1865 
  1866 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  1867 Posix processes.  Avoids potentially expensive forking of the ML
  1868 process.  New thread-based implementation also works on non-Unix
  1869 platforms (Cygwin).  Provers are no longer hardwired, but defined
  1870 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  1871 commands are covered in the isar-ref manual.
  1872 
  1873 * Wrapper scripts for remote SystemOnTPTP service allows to use
  1874 sledgehammer without local ATP installation (Vampire etc.). Other
  1875 provers may be included via suitable ML wrappers, see also
  1876 src/HOL/ATP_Linkup.thy.
  1877 
  1878 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  1879 menu.
  1880 
  1881 * The metis method no longer fails because the theorem is too trivial
  1882 (contains the empty clause).
  1883 
  1884 * The metis method now fails in the usual manner, rather than raising
  1885 an exception, if it determines that it cannot prove the theorem.
  1886 
  1887 * Method "coherent" implements a prover for coherent logic (see also
  1888 src/Tools/coherent.ML).
  1889 
  1890 * Constants "undefined" and "default" replace "arbitrary".  Usually
  1891 "undefined" is the right choice to replace "arbitrary", though
  1892 logically there is no difference.  INCOMPATIBILITY.
  1893 
  1894 * Command "value" now integrates different evaluation mechanisms.  The
  1895 result of the first successful evaluation mechanism is printed.  In
  1896 square brackets a particular named evaluation mechanisms may be
  1897 specified (currently, [SML], [code] or [nbe]).  See further
  1898 src/HOL/ex/Eval_Examples.thy.
  1899 
  1900 * Normalization by evaluation now allows non-leftlinear equations.
  1901 Declare with attribute [code nbe].
  1902 
  1903 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  1904 as the structured Isar versions "cases" and "induct", cf. the
  1905 corresponding "cases" and "induct" attributes.  Mutual induction rules
  1906 are now presented as a list of individual projections
  1907 (e.g. foo_bar.inducts for types foo and bar); the old format with
  1908 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  1909 rare situations a different rule is selected --- notably nested tuple
  1910 elimination instead of former prod.exhaust: use explicit (case_tac t
  1911 rule: prod.exhaust) here.
  1912 
  1913 * Attributes "cases", "induct", "coinduct" support "del" option.
  1914 
  1915 * Removed fact "case_split_thm", which duplicates "case_split".
  1916 
  1917 * The option datatype has been moved to a new theory Option.  Renamed
  1918 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  1919 
  1920 * New predicate "strict_mono" classifies strict functions on partial
  1921 orders.  With strict functions on linear orders, reasoning about
  1922 (in)equalities is facilitated by theorems "strict_mono_eq",
  1923 "strict_mono_less_eq" and "strict_mono_less".
  1924 
  1925 * Some set operations are now proper qualified constants with
  1926 authentic syntax.  INCOMPATIBILITY:
  1927 
  1928     op Int ~>   Set.Int
  1929     op Un ~>    Set.Un
  1930     INTER ~>    Set.INTER
  1931     UNION ~>    Set.UNION
  1932     Inter ~>    Set.Inter
  1933     Union ~>    Set.Union
  1934     {} ~>       Set.empty
  1935     UNIV ~>     Set.UNIV
  1936 
  1937 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  1938 theory Set.
  1939 
  1940 * Auxiliary class "itself" has disappeared -- classes without any
  1941 parameter are treated as expected by the 'class' command.
  1942 
  1943 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  1944 
  1945 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  1946 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  1947 
  1948 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  1949 method "approximation".  It proves formulas on real values by using
  1950 interval arithmetic.  In the formulas are also the transcendental
  1951 functions sin, cos, tan, atan, ln, exp and the constant pi are
  1952 allowed. For examples see
  1953 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  1954 
  1955 * Theory "Reflection" now resides in HOL/Library.
  1956 
  1957 * Entry point to Word library now simply named "Word".
  1958 INCOMPATIBILITY.
  1959 
  1960 * Made source layout more coherent with logical distribution
  1961 structure:
  1962 
  1963     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  1964     src/HOL/Library/Code_Message.thy ~> src/HOL/
  1965     src/HOL/Library/GCD.thy ~> src/HOL/
  1966     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  1967     src/HOL/Library/Parity.thy ~> src/HOL/
  1968     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  1969     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  1970     src/HOL/Real/Lubs.thy ~> src/HOL/
  1971     src/HOL/Real/PReal.thy ~> src/HOL/
  1972     src/HOL/Real/Rational.thy ~> src/HOL/
  1973     src/HOL/Real/RComplete.thy ~> src/HOL/
  1974     src/HOL/Real/RealDef.thy ~> src/HOL/
  1975     src/HOL/Real/RealPow.thy ~> src/HOL/
  1976     src/HOL/Real/Real.thy ~> src/HOL/
  1977     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  1978     src/HOL/Complex/Complex.thy ~> src/HOL/
  1979     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  1980     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  1981     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  1982     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  1983     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  1984     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  1985     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  1986     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  1987     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  1988     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  1989     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  1990     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  1991     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  1992     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  1993     src/HOL/Real/Float ~> src/HOL/Library/
  1994     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  1995     src/HOL/Real/RealVector.thy ~> src/HOL/
  1996 
  1997     src/HOL/arith_data.ML ~> src/HOL/Tools
  1998     src/HOL/hologic.ML ~> src/HOL/Tools
  1999     src/HOL/simpdata.ML ~> src/HOL/Tools
  2000     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2001     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2002     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2003     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2004     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2005     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2006     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2007 
  2008     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2009     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2010     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2011     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2012     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2013     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2014 
  2015 * If methods "eval" and "evaluation" encounter a structured proof
  2016 state with !!/==>, only the conclusion is evaluated to True (if
  2017 possible), avoiding strange error messages.
  2018 
  2019 * Method "sizechange" automates termination proofs using (a
  2020 modification of) the size-change principle.  Requires SAT solver.  See
  2021 src/HOL/ex/Termination.thy for examples.
  2022 
  2023 * Simplifier: simproc for let expressions now unfolds if bound
  2024 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2025 
  2026 * Method "arith": Linear arithmetic now ignores all inequalities when
  2027 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2028 
  2029 * New attribute "arith" for facts that should always be used
  2030 automatically by arithmetic. It is intended to be used locally in
  2031 proofs, e.g.
  2032 
  2033   assumes [arith]: "x > 0"
  2034 
  2035 Global usage is discouraged because of possible performance impact.
  2036 
  2037 * New classes "top" and "bot" with corresponding operations "top" and
  2038 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2039 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2040 
  2041 * Changed definition lemma "less_fun_def" in order to provide an
  2042 instance for preorders on functions; use lemma "less_le" instead.
  2043 INCOMPATIBILITY.
  2044 
  2045 * Theory Orderings: class "wellorder" moved here, with explicit
  2046 induction rule "less_induct" as assumption.  For instantiation of
  2047 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2048 INCOMPATIBILITY.
  2049 
  2050 * Theory Orderings: added class "preorder" as superclass of "order".
  2051 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2052 etc. slightly changed.  Some theorems named order_class.* now named
  2053 preorder_class.*.
  2054 
  2055 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2056 "diag" to "Id_on".
  2057 
  2058 * Theory Finite_Set: added a new fold combinator of type
  2059 
  2060   ('a => 'b => 'b) => 'b => 'a set => 'b
  2061 
  2062 Occasionally this is more convenient than the old fold combinator
  2063 which is now defined in terms of the new one and renamed to
  2064 fold_image.
  2065 
  2066 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2067 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2068 extended with further lemmas!).  At the moment both still exist but
  2069 the former will disappear at some point.
  2070 
  2071 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2072 class recpower.  Type-specific simp rules for various recpower types
  2073 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2074 
  2075 rat_power_0    -> power_0
  2076 rat_power_Suc  -> power_Suc
  2077 realpow_0      -> power_0
  2078 realpow_Suc    -> power_Suc
  2079 complexpow_0   -> power_0
  2080 complexpow_Suc -> power_Suc
  2081 power_poly_0   -> power_0
  2082 power_poly_Suc -> power_Suc
  2083 
  2084 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2085 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2086 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2087 of lemmas from Divides has been generalized from nat to class
  2088 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2089 renames resulting from duplicate elimination:
  2090 
  2091     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2092     zero_dvd_iff ~>         dvd_0_left_iff
  2093     dvd_0 ~>                dvd_0_right
  2094     DIVISION_BY_ZERO_DIV ~> div_by_0
  2095     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2096     mult_div ~>             div_mult_self2_is_id
  2097     mult_mod ~>             mod_mult_self2_is_0
  2098 
  2099 * Theory IntDiv: removed many lemmas that are instances of class-based
  2100 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2101 rename old lemmas as follows:
  2102 
  2103 dvd_diff               -> nat_dvd_diff
  2104 dvd_zminus_iff         -> dvd_minus_iff
  2105 mod_add1_eq            -> mod_add_eq
  2106 mod_mult1_eq           -> mod_mult_right_eq
  2107 mod_mult1_eq'          -> mod_mult_left_eq
  2108 mod_mult_distrib_mod   -> mod_mult_eq
  2109 nat_mod_add_left_eq    -> mod_add_left_eq
  2110 nat_mod_add_right_eq   -> mod_add_right_eq
  2111 nat_mod_div_trivial    -> mod_div_trivial
  2112 nat_mod_mod_trivial    -> mod_mod_trivial
  2113 zdiv_zadd_self1        -> div_add_self1
  2114 zdiv_zadd_self2        -> div_add_self2
  2115 zdiv_zmult_self1       -> div_mult_self2_is_id
  2116 zdiv_zmult_self2       -> div_mult_self1_is_id
  2117 zdvd_triv_left         -> dvd_triv_left
  2118 zdvd_triv_right        -> dvd_triv_right
  2119 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2120 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2121 zmod_zadd_left_eq      -> mod_add_left_eq
  2122 zmod_zadd_right_eq     -> mod_add_right_eq
  2123 zmod_zadd_self1        -> mod_add_self1
  2124 zmod_zadd_self2        -> mod_add_self2
  2125 zmod_zadd1_eq          -> mod_add_eq
  2126 zmod_zdiff1_eq         -> mod_diff_eq
  2127 zmod_zdvd_zmod         -> mod_mod_cancel
  2128 zmod_zmod_cancel       -> mod_mod_cancel
  2129 zmod_zmult_self1       -> mod_mult_self2_is_0
  2130 zmod_zmult_self2       -> mod_mult_self1_is_0
  2131 zmod_1                 -> mod_by_1
  2132 zdiv_1                 -> div_by_1
  2133 zdvd_abs1              -> abs_dvd_iff
  2134 zdvd_abs2              -> dvd_abs_iff
  2135 zdvd_refl              -> dvd_refl
  2136 zdvd_trans             -> dvd_trans
  2137 zdvd_zadd              -> dvd_add
  2138 zdvd_zdiff             -> dvd_diff
  2139 zdvd_zminus_iff        -> dvd_minus_iff
  2140 zdvd_zminus2_iff       -> minus_dvd_iff
  2141 zdvd_zmultD            -> dvd_mult_right
  2142 zdvd_zmultD2           -> dvd_mult_left
  2143 zdvd_zmult_mono        -> mult_dvd_mono
  2144 zdvd_0_right           -> dvd_0_right
  2145 zdvd_0_left            -> dvd_0_left_iff
  2146 zdvd_1_left            -> one_dvd
  2147 zminus_dvd_iff         -> minus_dvd_iff
  2148 
  2149 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2150 
  2151 * The real numbers offer decimal input syntax: 12.34 is translated
  2152 into 1234/10^2. This translation is not reversed upon output.
  2153 
  2154 * Theory Library/Polynomial defines an abstract type 'a poly of
  2155 univariate polynomials with coefficients of type 'a.  In addition to
  2156 the standard ring operations, it also supports div and mod.  Code
  2157 generation is also supported, using list-style constructors.
  2158 
  2159 * Theory Library/Inner_Product defines a class of real_inner for real
  2160 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2161 => real.  Class real_inner is a subclass of real_normed_vector from
  2162 theory RealVector.
  2163 
  2164 * Theory Library/Product_Vector provides instances for the product
  2165 type 'a * 'b of several classes from RealVector and Inner_Product.
  2166 Definitions of addition, subtraction, scalar multiplication, norms,
  2167 and inner products are included.
  2168 
  2169 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2170 addition to the field operations, numerals and case syntax are also
  2171 supported.
  2172 
  2173 * Theory Library/Diagonalize provides constructive version of Cantor's
  2174 first diagonalization argument.
  2175 
  2176 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2177 zlcm (for int); carried together from various gcd/lcm developements in
  2178 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2179 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2180 may recover tupled syntax as follows:
  2181 
  2182     hide (open) const gcd
  2183     abbreviation gcd where
  2184       "gcd == (%(a, b). GCD.gcd a b)"
  2185     notation (output)
  2186       GCD.gcd ("gcd '(_, _')")
  2187 
  2188 The same works for lcm, zgcd, zlcm.
  2189 
  2190 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2191 instantiations for algebraic structures.  Removed some duplicate
  2192 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2193 
  2194 * ML antiquotation @{code} takes a constant as argument and generates
  2195 corresponding code in background and inserts name of the corresponding
  2196 resulting ML value/function/datatype constructor binding in place.
  2197 All occurrences of @{code} with a single ML block are generated
  2198 simultaneously.  Provides a generic and safe interface for
  2199 instrumentalizing code generation.  See
  2200 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2201 In future you ought to refrain from ad-hoc compiling generated SML
  2202 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2203 cannot refer to constants for which user-defined serializations are
  2204 set.  Refer to the corresponding ML counterpart directly in that
  2205 cases.
  2206 
  2207 * Command 'rep_datatype': instead of theorem names the command now
  2208 takes a list of terms denoting the constructors of the type to be
  2209 represented as datatype.  The characteristic theorems have to be
  2210 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2211 have disappeared in favour of existing ones:
  2212 
  2213     unit_induct                 ~> unit.induct
  2214     prod_induct                 ~> prod.induct
  2215     sum_induct                  ~> sum.induct
  2216     Suc_Suc_eq                  ~> nat.inject
  2217     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2218 
  2219 
  2220 *** HOL-Algebra ***
  2221 
  2222 * New locales for orders and lattices where the equivalence relation
  2223 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2224 locales use a record structure with field eq for the equivalence.
  2225 
  2226 * New theory of factorial domains.
  2227 
  2228 * Units_l_inv and Units_r_inv are now simp rules by default.
  2229 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2230 and/or r_inv will now also require deletion of these lemmas.
  2231 
  2232 * Renamed the following theorems, INCOMPATIBILITY:
  2233 
  2234 UpperD ~> Upper_memD
  2235 LowerD ~> Lower_memD
  2236 least_carrier ~> least_closed
  2237 greatest_carrier ~> greatest_closed
  2238 greatest_Lower_above ~> greatest_Lower_below
  2239 one_zero ~> carrier_one_zero
  2240 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2241 
  2242 
  2243 *** HOL-Nominal ***
  2244 
  2245 * Nominal datatypes can now contain type-variables.
  2246 
  2247 * Commands 'nominal_inductive' and 'equivariance' work with local
  2248 theory targets.
  2249 
  2250 * Nominal primrec can now works with local theory targets and its
  2251 specification syntax now conforms to the general format as seen in
  2252 'inductive' etc.
  2253 
  2254 * Method "perm_simp" honours the standard simplifier attributes
  2255 (no_asm), (no_asm_use) etc.
  2256 
  2257 * The new predicate #* is defined like freshness, except that on the
  2258 left hand side can be a set or list of atoms.
  2259 
  2260 * Experimental command 'nominal_inductive2' derives strong induction
  2261 principles for inductive definitions.  In contrast to
  2262 'nominal_inductive', which can only deal with a fixed number of
  2263 binders, it can deal with arbitrary expressions standing for sets of
  2264 atoms to be avoided.  The only inductive definition we have at the
  2265 moment that needs this generalisation is the typing rule for Lets in
  2266 the algorithm W:
  2267 
  2268  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2269  -----------------------------------------------------------------
  2270          Gamma |- Let x be t1 in t2 : T2
  2271 
  2272 In this rule one wants to avoid all the binders that are introduced by
  2273 "close Gamma T1".  We are looking for other examples where this
  2274 feature might be useful.  Please let us know.
  2275 
  2276 
  2277 *** HOLCF ***
  2278 
  2279 * Reimplemented the simplification procedure for proving continuity
  2280 subgoals.  The new simproc is extensible; users can declare additional
  2281 continuity introduction rules with the attribute [cont2cont].
  2282 
  2283 * The continuity simproc now uses a different introduction rule for
  2284 solving continuity subgoals on terms with lambda abstractions.  In
  2285 some rare cases the new simproc may fail to solve subgoals that the
  2286 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2287 Potential INCOMPATIBILITY.
  2288 
  2289 * Command 'fixrec': specification syntax now conforms to the general
  2290 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2291 examples.  INCOMPATIBILITY.
  2292 
  2293 
  2294 *** ZF ***
  2295 
  2296 * Proof of Zorn's Lemma for partial orders.
  2297 
  2298 
  2299 *** ML ***
  2300 
  2301 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2302 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2303 depends on multithreading, so timouts will not work before Poly/ML
  2304 5.2.1!
  2305 
  2306 * High-level support for concurrent ML programming, see
  2307 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2308 particularly convenient to organize independent functional
  2309 computations.  The concept of "synchronized variables" provides a
  2310 higher-order interface for components with shared state, avoiding the
  2311 delicate details of mutexes and condition variables.  (Requires
  2312 Poly/ML 5.2.1 or later.)
  2313 
  2314 * ML bindings produced via Isar commands are stored within the Isar
  2315 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2316 become thread-safe and work with undo as expected (concerning
  2317 top-level bindings, not side-effects on global references).
  2318 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2319 compiler at runtime; really global bindings need to be given outside a
  2320 theory.  (Requires Poly/ML 5.2 or later.)
  2321 
  2322 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2323 context.  Top-level ML bindings are stored within the proof context in
  2324 a purely sequential fashion, disregarding the nested proof structure.
  2325 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2326 proof.  (Requires Poly/ML 5.2 or later.)
  2327 
  2328 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2329 and Method.setup, as well as Isar commands 'attribute_setup' and
  2330 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2331 existing code accordingly, or use plain 'setup' together with old
  2332 Method.add_method.
  2333 
  2334 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2335 to 'a -> thm, while results are always tagged with an authentic oracle
  2336 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2337 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2338 accordingly.  Note that extra performance may be gained by producing
  2339 the cterm carefully, avoiding slow Thm.cterm_of.
  2340 
  2341 * Simplified interface for defining document antiquotations via
  2342 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2343 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2344 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2345 examples.
  2346 
  2347 * More systematic treatment of long names, abstract name bindings, and
  2348 name space operations.  Basic operations on qualified names have been
  2349 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2350 Long_Name.append.  Old type bstring has been mostly replaced by
  2351 abstract type binding (see structure Binding), which supports precise
  2352 qualification by packages and local theory targets, as well as proper
  2353 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2354 bstring values into Binding.name, or better pass through abstract
  2355 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2356 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2357 
  2358 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2359 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2360 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2361 
  2362 * Disposed old type and term read functions (Sign.read_def_typ,
  2363 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2364 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2365 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2366 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2367 resort for legacy applications.
  2368 
  2369 * Disposed old declarations, tactics, tactic combinators that refer to
  2370 the simpset or claset of an implicit theory (such as Addsimps,
  2371 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2372 embedded ML text, or local_simpset_of with a proper context passed as
  2373 explicit runtime argument.
  2374 
  2375 * Rules and tactics that read instantiations (read_instantiate,
  2376 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2377 context, which is required for parsing and type-checking.  Moreover,
  2378 the variables are specified as plain indexnames, not string encodings
  2379 thereof.  INCOMPATIBILITY.
  2380 
  2381 * Generic Toplevel.add_hook interface allows to analyze the result of
  2382 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2383 for theorem dependency output of transactions resulting in a new
  2384 theory state.
  2385 
  2386 * ML antiquotations: block-structured compilation context indicated by
  2387 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2388 
  2389   @{binding name}                         - basic name binding
  2390   @{let ?pat = term}                      - term abbreviation (HO matching)
  2391   @{note name = fact}                     - fact abbreviation
  2392   @{thm fact}                             - singleton fact (with attributes)
  2393   @{thms fact}                            - general fact (with attributes)
  2394   @{lemma prop by method}                 - singleton goal
  2395   @{lemma prop by meth1 meth2}            - singleton goal
  2396   @{lemma prop1 ... propN by method}      - general goal
  2397   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2398   @{lemma (open) ...}                     - open derivation
  2399 
  2400 
  2401 *** System ***
  2402 
  2403 * The Isabelle "emacs" tool provides a specific interface to invoke
  2404 Proof General / Emacs, with more explicit failure if that is not
  2405 installed (the old isabelle-interface script silently falls back on
  2406 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2407 installation location of the Proof General distribution.
  2408 
  2409 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2410 the Isabelle process into a JVM/Scala application.  See
  2411 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2412 process wrapper has been discontinued.)
  2413 
  2414 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2415 
  2416 * Various status messages (with exact source position information) are
  2417 emitted, if proper markup print mode is enabled.  This allows
  2418 user-interface components to provide detailed feedback on internal
  2419 prover operations.
  2420 
  2421 
  2422 
  2423 New in Isabelle2008 (June 2008)
  2424 -------------------------------
  2425 
  2426 *** General ***
  2427 
  2428 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2429 and updated, with formally checked references as hyperlinks.
  2430 
  2431 * Theory loader: use_thy (and similar operations) no longer set the
  2432 implicit ML context, which was occasionally hard to predict and in
  2433 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2434 provides a proper context already.
  2435 
  2436 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2437 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2438 'use' within a theory file will do the job.
  2439 
  2440 * Name space merge now observes canonical order, i.e. the second space
  2441 is inserted into the first one, while existing entries in the first
  2442 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2443 swap theory imports.
  2444 
  2445 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2446 INCOMPATIBILITY in identifier syntax etc.
  2447 
  2448 * Outer syntax: string tokens no longer admit escaped white space,
  2449 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2450 white space without escapes.
  2451 
  2452 * Outer syntax: string tokens may contain arbitrary character codes
  2453 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2454 "foo_bar".
  2455 
  2456 
  2457 *** Pure ***
  2458 
  2459 * Context-dependent token translations.  Default setup reverts locally
  2460 fixed variables, and adds hilite markup for undeclared frees.
  2461 
  2462 * Unused theorems can be found using the new command 'unused_thms'.
  2463 There are three ways of invoking it:
  2464 
  2465 (1) unused_thms
  2466      Only finds unused theorems in the current theory.
  2467 
  2468 (2) unused_thms thy_1 ... thy_n -
  2469      Finds unused theorems in the current theory and all of its ancestors,
  2470      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2471 
  2472 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2473      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2474      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2475      their ancestors.
  2476 
  2477 In order to increase the readability of the list produced by
  2478 unused_thms, theorems that have been created by a particular instance
  2479 of a theory command such as 'inductive' or 'function' are considered
  2480 to belong to the same "group", meaning that if at least one theorem in
  2481 this group is used, the other theorems in the same group are no longer
  2482 reported as unused.  Moreover, if all theorems in the group are
  2483 unused, only one theorem in the group is displayed.
  2484 
  2485 Note that proof objects have to be switched on in order for
  2486 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2487 usually the case when using Proof General with the default settings).
  2488 
  2489 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2490 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2491 duplicate fact bindings, or even accidental fact duplications.  Note
  2492 that tools may maintain dynamically scoped facts systematically, using
  2493 PureThy.add_thms_dynamic.
  2494 
  2495 * Command 'hide' now allows to hide from "fact" name space as well.
  2496 
  2497 * Eliminated destructive theorem database, simpset, claset, and
  2498 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2499 update of theories within ML code.
  2500 
  2501 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2502 INCOMPATIBILITY, object-logics depending on former Pure require
  2503 additional setup PureThy.old_appl_syntax_setup; object-logics
  2504 depending on former CPure need to refer to Pure.
  2505 
  2506 * Commands 'use' and 'ML' are now purely functional, operating on
  2507 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2508 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2509 INCOMPATIBILITY.
  2510 
  2511 * Command 'setup': discontinued implicit version with ML reference.
  2512 
  2513 * Instantiation target allows for simultaneous specification of class
  2514 instance operations together with an instantiation proof.
  2515 Type-checking phase allows to refer to class operations uniformly.
  2516 See src/HOL/Complex/Complex.thy for an Isar example and
  2517 src/HOL/Library/Eval.thy for an ML example.
  2518 
  2519 * Indexing of literal facts: be more serious about including only
  2520 facts from the visible specification/proof context, but not the
  2521 background context (locale etc.).  Affects `prop` notation and method
  2522 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2523 situations.
  2524 
  2525 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2526 "(open)" option, which used to expose internal bound variables to the
  2527 proof text.
  2528 
  2529 * Isar statements: removed obsolete case "rule_context".
  2530 INCOMPATIBILITY, better use explicit fixes/assumes.
  2531 
  2532 * Locale proofs: default proof step now includes 'unfold_locales';
  2533 hence 'proof' without argument may be used to unfold locale
  2534 predicates.
  2535 
  2536 
  2537 *** Document preparation ***
  2538 
  2539 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2540 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2541 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2542 spot); renamed link color from "darkblue" to "linkcolor" (default
  2543 value unchanged, can be redefined via \definecolor); no longer sets
  2544 "a4paper" option (unnecessary or even intrusive).
  2545 
  2546 * Antiquotation @{lemma A method} proves proposition A by the given
  2547 method (either a method name or a method name plus (optional) method
  2548 arguments in parentheses) and prints A just like @{prop A}.
  2549 
  2550 
  2551 *** HOL ***
  2552 
  2553 * New primrec package.  Specification syntax conforms in style to
  2554 definition/function/....  No separate induction rule is provided.  The
  2555 "primrec" command distinguishes old-style and new-style specifications
  2556 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2557 When adjusting theories, beware: constants stemming from new-style
  2558 primrec specifications have authentic syntax.
  2559 
  2560 * Metis prover is now an order of magnitude faster, and also works
  2561 with multithreading.
  2562 
  2563 * Metis: the maximum number of clauses that can be produced from a
  2564 theorem is now given by the attribute max_clauses.  Theorems that
  2565 exceed this number are ignored, with a warning printed.
  2566 
  2567 * Sledgehammer no longer produces structured proofs by default. To
  2568 enable, declare [[sledgehammer_full = true]].  Attributes
  2569 reconstruction_modulus, reconstruction_sorts renamed
  2570 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2571 
  2572 * Method "induct_scheme" derives user-specified induction rules
  2573 from well-founded induction and completeness of patterns. This factors
  2574 out some operations that are done internally by the function package
  2575 and makes them available separately.  See
  2576 src/HOL/ex/Induction_Scheme.thy for examples.
  2577 
  2578 * More flexible generation of measure functions for termination
  2579 proofs: Measure functions can be declared by proving a rule of the
  2580 form "is_measure f" and giving it the [measure_function] attribute.
  2581 The "is_measure" predicate is logically meaningless (always true), and
  2582 just guides the heuristic.  To find suitable measure functions, the
  2583 termination prover sets up the goal "is_measure ?f" of the appropriate
  2584 type and generates all solutions by prolog-style backwards proof using
  2585 the declared rules.
  2586 
  2587 This setup also deals with rules like 
  2588 
  2589   "is_measure f ==> is_measure (list_size f)"
  2590 
  2591 which accommodates nested datatypes that recurse through lists.
  2592 Similar rules are predeclared for products and option types.
  2593 
  2594 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2595 
  2596   INCOMPATIBILITIES:
  2597 
  2598   - Definitions of overloaded constants on sets have to be replaced by
  2599     definitions on => and bool.
  2600 
  2601   - Some definitions of overloaded operators on sets can now be proved
  2602     using the definitions of the operators on => and bool.  Therefore,
  2603     the following theorems have been renamed:
  2604 
  2605       subset_def   -> subset_eq
  2606       psubset_def  -> psubset_eq
  2607       set_diff_def -> set_diff_eq
  2608       Compl_def    -> Compl_eq
  2609       Sup_set_def  -> Sup_set_eq
  2610       Inf_set_def  -> Inf_set_eq
  2611       sup_set_def  -> sup_set_eq
  2612       inf_set_def  -> inf_set_eq
  2613 
  2614   - Due to the incompleteness of the HO unification algorithm, some
  2615     rules such as subst may require manual instantiation, if some of
  2616     the unknowns in the rule is a set.
  2617 
  2618   - Higher order unification and forward proofs:
  2619     The proof pattern
  2620 
  2621       have "P (S::'a set)" <...>
  2622       then have "EX S. P S" ..
  2623 
  2624     no longer works (due to the incompleteness of the HO unification
  2625     algorithm) and must be replaced by the pattern
  2626 
  2627       have "EX S. P S"
  2628       proof
  2629         show "P S" <...>
  2630       qed
  2631 
  2632   - Calculational reasoning with subst (or similar rules):
  2633     The proof pattern
  2634 
  2635       have "P (S::'a set)" <...>
  2636       also have "S = T" <...>
  2637       finally have "P T" .
  2638 
  2639     no longer works (for similar reasons as the previous example) and
  2640     must be replaced by something like
  2641 
  2642       have "P (S::'a set)" <...>
  2643       moreover have "S = T" <...>
  2644       ultimately have "P T" by simp
  2645 
  2646   - Tactics or packages written in ML code:
  2647     Code performing pattern matching on types via
  2648 
  2649       Type ("set", [T]) => ...
  2650 
  2651     must be rewritten. Moreover, functions like strip_type or
  2652     binder_types no longer return the right value when applied to a
  2653     type of the form
  2654 
  2655       T1 => ... => Tn => U => bool
  2656 
  2657     rather than
  2658 
  2659       T1 => ... => Tn => U set
  2660 
  2661 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2662 Wellfounded_Relations to theory Wellfounded.
  2663 
  2664 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2665 
  2666 * Class finite no longer treats UNIV as class parameter.  Use class
  2667 enum from theory Library/Enum instead to achieve a similar effect.
  2668 INCOMPATIBILITY.
  2669 
  2670 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2671 and "Cons".  INCOMPATIBILITY.
  2672 
  2673 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2674 Potential INCOMPATIBILITY.
  2675 
  2676 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2677 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2678 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2679 
  2680 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2681 the same name in theory Orderings:
  2682 
  2683   less_trans
  2684   less_linear
  2685   le_imp_less_or_eq
  2686   le_less_trans
  2687   less_le_trans
  2688   less_not_sym
  2689   less_asym
  2690 
  2691 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2692 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2693 and different variable names.
  2694 
  2695 * Library/Option_ord.thy: Canonical order on option type.
  2696 
  2697 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2698 finite maps.
  2699 
  2700 * Library/Countable.thy: Type class for countable types.
  2701 
  2702 * Theory Int: The representation of numerals has changed.  The infix
  2703 operator BIT and the bit datatype with constructors B0 and B1 have
  2704 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2705 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2706 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2707 accordingly.
  2708 
  2709 * Theory Nat: definition of <= and < on natural numbers no longer
  2710 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2711 le_def and less_def have disappeared.  Consider lemmas not_less
  2712 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2713 
  2714 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2715 (whose purpose mainly is for various fold_set functionals) have been
  2716 abandoned in favor of the existing algebraic classes
  2717 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2718 lower_semilattice (resp. upper_semilattice) and linorder.
  2719 INCOMPATIBILITY.
  2720 
  2721 * Theory Transitive_Closure: induct and cases rules now declare proper
  2722 case_names ("base" and "step").  INCOMPATIBILITY.
  2723 
  2724 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2725 lattices.  The form set-specific version is available as
  2726 Inductive.lfp_ordinal_induct_set.
  2727 
  2728 * Renamed theorems "power.simps" to "power_int.simps".
  2729 INCOMPATIBILITY.
  2730 
  2731 * Class semiring_div provides basic abstract properties of semirings
  2732 with division and modulo operations.  Subsumes former class dvd_mod.
  2733 
  2734 * Merged theories IntDef, Numeral and IntArith into unified theory
  2735 Int.  INCOMPATIBILITY.
  2736 
  2737 * Theory Library/Code_Index: type "index" now represents natural
  2738 numbers rather than integers.  INCOMPATIBILITY.
  2739 
  2740 * New class "uminus" with operation "uminus" (split of from class
  2741 "minus" which now only has operation "minus", binary).
  2742 INCOMPATIBILITY.
  2743 
  2744 * Constants "card", "internal_split", "option_map" now with authentic
  2745 syntax.  INCOMPATIBILITY.
  2746 
  2747 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2748 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2749 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2750 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2751 Sup_set_def, le_def, less_def, option_map_def now with object
  2752 equality.  INCOMPATIBILITY.
  2753 
  2754 * Records. Removed K_record, and replaced it by pure lambda term
  2755 %x. c. The simplifier setup is now more robust against eta expansion.
  2756 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2757 
  2758 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2759 
  2760 * Library/ListVector: new theory of arithmetic vector operations.
  2761 
  2762 * Library/Order_Relation: new theory of various orderings as sets of
  2763 pairs.  Defines preorders, partial orders, linear orders and
  2764 well-orders on sets and on types.
  2765 
  2766 
  2767 *** ZF ***
  2768 
  2769 * Renamed some theories to allow to loading both ZF and HOL in the
  2770 same session:
  2771 
  2772   Datatype  -> Datatype_ZF
  2773   Inductive -> Inductive_ZF
  2774   Int       -> Int_ZF
  2775   IntDiv    -> IntDiv_ZF
  2776   Nat       -> Nat_ZF
  2777   List      -> List_ZF
  2778   Main      -> Main_ZF
  2779 
  2780 INCOMPATIBILITY: ZF theories that import individual theories below
  2781 Main might need to be adapted.  Regular theory Main is still
  2782 available, as trivial extension of Main_ZF.
  2783 
  2784 
  2785 *** ML ***
  2786 
  2787 * ML within Isar: antiquotation @{const name} or @{const
  2788 name(typargs)} produces statically-checked Const term.
  2789 
  2790 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2791 (of the same name).  Removed obsolete print command.
  2792 
  2793 * Removed obsolete "use_legacy_bindings" function.
  2794 
  2795 * The ``print mode'' is now a thread-local value derived from a global
  2796 template (the former print_mode reference), thus access becomes
  2797 non-critical.  The global print_mode reference is for session
  2798 management only; user-code should use print_mode_value,
  2799 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2800 
  2801 * Functions system/system_out provide a robust way to invoke external
  2802 shell commands, with propagation of interrupts (requires Poly/ML
  2803 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2804 
  2805 
  2806 *** System ***
  2807 
  2808 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  2809 in accordance with Proof General 3.7, which prefers GNU emacs.
  2810 
  2811 * isatool tty runs Isabelle process with plain tty interaction;
  2812 optional line editor may be specified via ISABELLE_LINE_EDITOR
  2813 setting, the default settings attempt to locate "ledit" and "rlwrap".
  2814 
  2815 * isatool browser now works with Cygwin as well, using general
  2816 "javapath" function defined in Isabelle process environment.
  2817 
  2818 * YXML notation provides a simple and efficient alternative to
  2819 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  2820 isatool yxml as described in the Isabelle system manual.
  2821 
  2822 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  2823 provides general wrapper for managing an Isabelle process in a robust
  2824 fashion, with ``cooked'' output from stdin/stderr.
  2825 
  2826 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  2827 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  2828 
  2829 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  2830 way of changing the user's settings is via
  2831 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  2832 script.
  2833 
  2834 * Multithreading.max_threads := 0 refers to the number of actual CPU
  2835 cores of the underlying machine, which is a good starting point for
  2836 optimal performance tuning.  The corresponding usedir option -M allows
  2837 "max" as an alias for "0".  WARNING: does not work on certain versions
  2838 of Mac OS (with Poly/ML 5.1).
  2839 
  2840 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  2841 adverse effect of Isabelle flooding interactive front-ends (notably
  2842 ProofGeneral / XEmacs).
  2843 
  2844 
  2845 
  2846 New in Isabelle2007 (November 2007)
  2847 -----------------------------------
  2848 
  2849 *** General ***
  2850 
  2851 * More uniform information about legacy features, notably a
  2852 warning/error of "Legacy feature: ...", depending on the state of the
  2853 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  2854 legacy features will disappear eventually.
  2855 
  2856 * Theory syntax: the header format ``theory A = B + C:'' has been
  2857 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  2858 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  2859 
  2860 * Theory syntax: the old non-Isar theory file format has been
  2861 discontinued altogether.  Note that ML proof scripts may still be used
  2862 with Isar theories; migration is usually quite simple with the ML
  2863 function use_legacy_bindings.  INCOMPATIBILITY.
  2864 
  2865 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  2866 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  2867 quotes.
  2868 
  2869 * Theory loader: be more serious about observing the static theory
  2870 header specifications (including optional directories), but not the
  2871 accidental file locations of previously successful loads.  The strict
  2872 update policy of former update_thy is now already performed by
  2873 use_thy, so the former has been removed; use_thys updates several
  2874 theories simultaneously, just as 'imports' within a theory header
  2875 specification, but without merging the results.  Potential
  2876 INCOMPATIBILITY: may need to refine theory headers and commands
  2877 ROOT.ML which depend on load order.
  2878 
  2879 * Theory loader: optional support for content-based file
  2880 identification, instead of the traditional scheme of full physical
  2881 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  2882 (cf. the system manual).  The new scheme allows to work with
  2883 non-finished theories in persistent session images, such that source
  2884 files may be moved later on without requiring reloads.
  2885 
  2886 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2887 file (with the same base name as the theory) are considered a legacy
  2888 feature, which will disappear eventually. Even now, the theory loader
  2889 no longer maintains dependencies on such files.
  2890 
  2891 * Syntax: the scope for resolving ambiguities via type-inference is
  2892 now limited to individual terms, instead of whole simultaneous
  2893 specifications as before. This greatly reduces the complexity of the
  2894 syntax module and improves flexibility by separating parsing and
  2895 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  2896 'fixes' etc.) are required in rare situations.
  2897 
  2898 * Syntax: constants introduced by new-style packages ('definition',
  2899 'abbreviation' etc.) are passed through the syntax module in
  2900 ``authentic mode''. This means that associated mixfix annotations
  2901 really stick to such constants, independently of potential name space
  2902 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  2903 trees are represented slightly differently, may need to adapt syntax
  2904 translations accordingly. Use CONST marker in 'translations' and
  2905 @{const_syntax} antiquotation in 'parse_translation' etc.
  2906 
  2907 * Legacy goal package: reduced interface to the bare minimum required
  2908 to keep existing proof scripts running.  Most other user-level
  2909 functions are now part of the OldGoals structure, which is *not* open
  2910 by default (consider isatool expandshort before open OldGoals).
  2911 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  2912 these tend to cause confusion about the actual goal (!) context being
  2913 used here, which is not necessarily the same as the_context().
  2914 
  2915 * Command 'find_theorems': supports "*" wild-card in "name:"
  2916 criterion; "with_dups" option.  Certain ProofGeneral versions might
  2917 support a specific search form (see ProofGeneral/CHANGES).
  2918 
  2919 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  2920 by default, which means that "prems" (and also "fixed variables") are
  2921 suppressed from proof state output.  Note that the ProofGeneral
  2922 settings mechanism allows to change and save options persistently, but
  2923 older versions of Isabelle will fail to start up if a negative prems
  2924 limit is imposed.
  2925 
  2926 * Local theory targets may be specified by non-nested blocks of
  2927 ``context/locale/class ... begin'' followed by ``end''.  The body may
  2928 contain definitions, theorems etc., including any derived mechanism
  2929 that has been implemented on top of these primitives.  This concept
  2930 generalizes the existing ``theorem (in ...)'' towards more versatility
  2931 and scalability.
  2932 
  2933 * Proof General interface: proper undo of final 'end' command;
  2934 discontinued Isabelle/classic mode (ML proof scripts).
  2935 
  2936 
  2937 *** Document preparation ***
  2938 
  2939 * Added antiquotation @{theory name} which prints the given name,
  2940 after checking that it refers to a valid ancestor theory in the
  2941 current context.
  2942 
  2943 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  2944 check the given source text as ML type/structure, printing verbatim.
  2945 
  2946 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  2947 "c args == rhs" given in the current context.  (Any number of
  2948 arguments may be given on the LHS.)
  2949 
  2950 
  2951 *** Pure ***
  2952 
  2953 * The 'class' package offers a combination of axclass and locale to
  2954 achieve Haskell-like type classes in Isabelle.  Definitions and
  2955 theorems within a class context produce both relative results (with
  2956 implicit parameters according to the locale context), and polymorphic
  2957 constants with qualified polymorphism (according to the class
  2958 context).  Within the body context of a 'class' target, a separate
  2959 syntax layer ("user space type system") takes care of converting
  2960 between global polymorphic consts and internal locale representation.
  2961 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  2962 "isatool doc classes" provides a tutorial.
  2963 
  2964 * Generic code generator framework allows to generate executable
  2965 code for ML and Haskell (including Isabelle classes).  A short usage
  2966 sketch:
  2967 
  2968     internal compilation:
  2969         export_code <list of constants (term syntax)> in SML
  2970     writing SML code to a file:
  2971         export_code <list of constants (term syntax)> in SML <filename>
  2972     writing OCaml code to a file:
  2973         export_code <list of constants (term syntax)> in OCaml <filename>
  2974     writing Haskell code to a bunch of files:
  2975         export_code <list of constants (term syntax)> in Haskell <filename>
  2976 
  2977     evaluating closed propositions to True/False using code generation:
  2978         method ``eval''
  2979 
  2980 Reasonable default setup of framework in HOL.
  2981 
  2982 Theorem attributs for selecting and transforming function equations theorems:
  2983 
  2984     [code fun]:        select a theorem as function equation for a specific constant
  2985     [code fun del]:    deselect a theorem as function equation for a specific constant
  2986     [code inline]:     select an equation theorem for unfolding (inlining) in place
  2987     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  2988 
  2989 User-defined serializations (target in {SML, OCaml, Haskell}):
  2990 
  2991     code_const <and-list of constants (term syntax)>
  2992       {(target) <and-list of const target syntax>}+
  2993 
  2994     code_type <and-list of type constructors>
  2995       {(target) <and-list of type target syntax>}+
  2996 
  2997     code_instance <and-list of instances>
  2998       {(target)}+
  2999         where instance ::= <type constructor> :: <class>
  3000 
  3001     code_class <and_list of classes>
  3002       {(target) <and-list of class target syntax>}+
  3003         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3004 
  3005 code_instance and code_class only are effective to target Haskell.
  3006 
  3007 For example usage see src/HOL/ex/Codegenerator.thy and
  3008 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3009 generation from Isabelle/HOL theories is available via "isatool doc
  3010 codegen".
  3011 
  3012 * Code generator: consts in 'consts_code' Isar commands are now
  3013 referred to by usual term syntax (including optional type
  3014 annotations).
  3015 
  3016 * Command 'no_translations' removes translation rules from theory
  3017 syntax.
  3018 
  3019 * Overloaded definitions are now actually checked for acyclic
  3020 dependencies.  The overloading scheme is slightly more general than
  3021 that of Haskell98, although Isabelle does not demand an exact
  3022 correspondence to type class and instance declarations.
  3023 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3024 exotic versions of overloading -- at the discretion of the user!
  3025 
  3026 Polymorphic constants are represented via type arguments, i.e. the
  3027 instantiation that matches an instance against the most general
  3028 declaration given in the signature.  For example, with the declaration
  3029 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3030 as c(nat).  Overloading is essentially simultaneous structural
  3031 recursion over such type arguments.  Incomplete specification patterns
  3032 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3033 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3034 Command 'print_theory' outputs the normalized system of recursive
  3035 equations, see section "definitions".
  3036 
  3037 * Configuration options are maintained within the theory or proof
  3038 context (with name and type bool/int/string), providing a very simple
  3039 interface to a poor-man's version of general context data.  Tools may
  3040 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3041 these values using Config.get etc.  Users may change options via an
  3042 associated attribute of the same name.  This form of context
  3043 declaration works particularly well with commands 'declare' or
  3044 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3045 very easy to avoid global references, which would not observe Isar
  3046 toplevel undo/redo and fail to work with multithreading.
  3047 
  3048 Various global ML references of Pure and HOL have been turned into
  3049 configuration options:
  3050 
  3051   Unify.search_bound		unify_search_bound
  3052   Unify.trace_bound		unify_trace_bound
  3053   Unify.trace_simp		unify_trace_simp
  3054   Unify.trace_types		unify_trace_types
  3055   Simplifier.simp_depth_limit	simp_depth_limit
  3056   Blast.depth_limit		blast_depth_limit
  3057   DatatypeProp.dtK		datatype_distinctness_limit
  3058   fast_arith_neq_limit  	fast_arith_neq_limit
  3059   fast_arith_split_limit	fast_arith_split_limit
  3060 
  3061 * Named collections of theorems may be easily installed as context
  3062 data using the functor NamedThmsFun (see also
  3063 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3064 attributes; there is also a toplevel print command.  This facility is
  3065 just a common case of general context data, which is the preferred way
  3066 for anything more complex than just a list of facts in canonical
  3067 order.
  3068 
  3069 * Isar: command 'declaration' augments a local theory by generic
  3070 declaration functions written in ML.  This enables arbitrary content
  3071 being added to the context, depending on a morphism that tells the
  3072 difference of the original declaration context wrt. the application
  3073 context encountered later on.
  3074 
  3075 * Isar: proper interfaces for simplification procedures.  Command
  3076 'simproc_setup' declares named simprocs (with match patterns, and body
  3077 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3078 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3079 
  3080 * Isar: an extra pair of brackets around attribute declarations
  3081 abbreviates a theorem reference involving an internal dummy fact,
  3082 which will be ignored later --- only the effect of the attribute on
  3083 the background context will persist.  This form of in-place
  3084 declarations is particularly useful with commands like 'declare' and
  3085 'using', for example ``have A using [[simproc a]] by simp''.
  3086 
  3087 * Isar: method "assumption" (and implicit closing of subproofs) now
  3088 takes simple non-atomic goal assumptions into account: after applying
  3089 an assumption as a rule the resulting subgoals are solved by atomic
  3090 assumption steps.  This is particularly useful to finish 'obtain'
  3091 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3092 without referring to the original premise "!!x. P x ==> thesis" in the
  3093 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3094 more permissive.
  3095 
  3096 * Isar: implicit use of prems from the Isar proof context is
  3097 considered a legacy feature.  Common applications like ``have A .''
  3098 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3099 referencing facts explicitly here improves readability and
  3100 maintainability of proof texts.
  3101 
  3102 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3103 the obtained context from the course of reasoning!  For example:
  3104 
  3105   assume "EX x y. A x & B y"   -- "any previous fact"
  3106   then guess x and y by clarify
  3107 
  3108 This technique is potentially adventurous, depending on the facts and
  3109 proof tools being involved here.
  3110 
  3111 * Isar: known facts from the proof context may be specified as literal
  3112 propositions, using ASCII back-quote syntax.  This works wherever
  3113 named facts used to be allowed so far, in proof commands, proof
  3114 methods, attributes etc.  Literal facts are retrieved from the context
  3115 according to unification of type and term parameters.  For example,
  3116 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3117 theorems in the current context, then these are valid literal facts:
  3118 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3119 
  3120 There is also a proof method "fact" which does the same composition
  3121 for explicit goal states, e.g. the following proof texts coincide with
  3122 certain special cases of literal facts:
  3123 
  3124   have "A" by fact                 ==  note `A`
  3125   have "A ==> B" by fact           ==  note `A ==> B`
  3126   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3127   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3128 
  3129 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3130 outer syntax.  Thus symbolic identifiers may be used without
  3131 additional white space in declarations like this: ``assume *: A''.
  3132 
  3133 * Isar: 'print_facts' prints all local facts of the current context,
  3134 both named and unnamed ones.
  3135 
  3136 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3137 
  3138   def x == "t" and y == "u"
  3139 
  3140 * Isar: added command 'unfolding', which is structurally similar to
  3141 'using', but affects both the goal state and facts by unfolding given
  3142 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3143 'unfolded' attribute may be replaced by first-class proof text.
  3144 
  3145 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3146 and command 'unfolding' now all support object-level equalities
  3147 (potentially conditional).  The underlying notion of rewrite rule is
  3148 analogous to the 'rule_format' attribute, but *not* that of the
  3149 Simplifier (which is usually more generous).
  3150 
  3151 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3152 premises of a theorem by n. Useful in conjunction with drule.
  3153 
  3154 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3155 method expression within a sandbox consisting of the first N
  3156 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3157 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3158 simplifies all new goals that emerge from applying rule foo to the
  3159 originally first one.
  3160 
  3161 * Isar: schematic goals are no longer restricted to higher-order
  3162 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3163 expected.
  3164 
  3165 * Isar: the conclusion of a long theorem statement is now either
  3166 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3167 (essentially a disjunction of cases with local parameters and
  3168 assumptions).  The latter allows to express general elimination rules
  3169 adequately; in this notation common elimination rules look like this:
  3170 
  3171   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3172     assumes "EX x. P x"
  3173     obtains x where "P x"
  3174 
  3175   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3176     assumes "A & B"
  3177     obtains A and B
  3178 
  3179   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3180     assumes "A | B"
  3181     obtains
  3182       A
  3183     | B
  3184 
  3185 The subsequent classical rules even refer to the formal "thesis"
  3186 explicitly:
  3187 
  3188   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3189     obtains "~ thesis"
  3190 
  3191   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3192     obtains "thesis ==> something"
  3193 
  3194 The actual proof of an 'obtains' statement is analogous to that of the
  3195 Isar proof element 'obtain', only that there may be several cases.
  3196 Optional case names may be specified in parentheses; these will be
  3197 available both in the present proof and as annotations in the
  3198 resulting rule, for later use with the 'cases' method (cf. attribute
  3199 case_names).
  3200 
  3201 * Isar: the assumptions of a long theorem statement are available as
  3202 "assms" fact in the proof context.  This is more appropriate than the
  3203 (historical) "prems", which refers to all assumptions of the current
  3204 context, including those from the target locale, proof body etc.
  3205 
  3206 * Isar: 'print_statement' prints theorems from the current theory or
  3207 proof context in long statement form, according to the syntax of a
  3208 top-level lemma.
  3209 
  3210 * Isar: 'obtain' takes an optional case name for the local context
  3211 introduction rule (default "that").
  3212 
  3213 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3214 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3215 to occur.
  3216 
  3217 * Pure: syntax "CONST name" produces a fully internalized constant
  3218 according to the current context.  This is particularly useful for
  3219 syntax translations that should refer to internal constant
  3220 representations independently of name spaces.
  3221 
  3222 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3223 instead of "FOO ". This allows multiple binder declarations to coexist
  3224 in the same context.  INCOMPATIBILITY.
  3225 
  3226 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3227 primitive that also works in a locale context (both for constants and
  3228 fixed variables). Type declaration and internal syntactic representation
  3229 of given constants retrieved from the context. Likewise, the
  3230 'no_notation' command allows to remove given syntax annotations from the
  3231 current context.
  3232 
  3233 * Isar/locales: new derived specification elements 'axiomatization',
  3234 'definition', 'abbreviation', which support type-inference, admit
  3235 object-level specifications (equality, equivalence).  See also the
  3236 isar-ref manual.  Examples:
  3237 
  3238   axiomatization
  3239     eq  (infix "===" 50) where
  3240     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3241 
  3242   definition "f x y = x + y + 1"
  3243   definition g where "g x = f x x"
  3244 
  3245   abbreviation
  3246     neq  (infix "=!=" 50) where
  3247     "x =!= y == ~ (x === y)"
  3248 
  3249 These specifications may be also used in a locale context.  Then the
  3250 constants being introduced depend on certain fixed parameters, and the
  3251 constant name is qualified by the locale base name.  An internal
  3252 abbreviation takes care for convenient input and output, making the
  3253 parameters implicit and using the original short name.  See also
  3254 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3255 entities from a monomorphic theory.
  3256 
  3257 Presently, abbreviations are only available 'in' a target locale, but
  3258 not inherited by general import expressions.  Also note that
  3259 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3260 'translations' in common applications.  The "no_abbrevs" print mode
  3261 prevents folding of abbreviations in term output.
  3262 
  3263 Concrete syntax is attached to specified constants in internal form,
  3264 independently of name spaces.  The parse tree representation is
  3265 slightly different -- use 'notation' instead of raw 'syntax', and
  3266 'translations' with explicit "CONST" markup to accommodate this.
  3267 
  3268 * Pure/Isar: unified syntax for new-style specification mechanisms
  3269 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3270 full type inference and dummy patterns ("_").  For example:
  3271 
  3272   definition "K x _ = x"
  3273 
  3274   inductive conj for A B
  3275   where "A ==> B ==> conj A B"
  3276 
  3277 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3278 the current context.  Print mode "no_abbrevs" prevents inversion of
  3279 abbreviations on output.
  3280 
  3281 * Isar/locales: improved parameter handling: use of locales "var" and
  3282 "struct" no longer necessary; - parameter renamings are no longer
  3283 required to be injective.  For example, this allows to define
  3284 endomorphisms as locale endom = homom mult mult h.
  3285 
  3286 * Isar/locales: changed the way locales with predicates are defined.
  3287 Instead of accumulating the specification, the imported expression is
  3288 now an interpretation.  INCOMPATIBILITY: different normal form of
  3289 locale expressions.  In particular, in interpretations of locales with
  3290 predicates, goals repesenting already interpreted fragments are not
  3291 removed automatically.  Use methods `intro_locales' and
  3292 `unfold_locales'; see below.
  3293 
  3294 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3295 provide backward reasoning on locales predicates.  The methods are
  3296 aware of interpretations and discharge corresponding goals.
  3297 `intro_locales' is less aggressive then `unfold_locales' and does not
  3298 unfold predicates to assumptions.
  3299 
  3300 * Isar/locales: the order in which locale fragments are accumulated
  3301 has changed.  This enables to override declarations from fragments due
  3302 to interpretations -- for example, unwanted simp rules.
  3303 
  3304 * Isar/locales: interpretation in theories and proof contexts has been
  3305 extended.  One may now specify (and prove) equations, which are
  3306 unfolded in interpreted theorems.  This is useful for replacing
  3307 defined concepts (constants depending on locale parameters) by
  3308 concepts already existing in the target context.  Example:
  3309 
  3310   interpretation partial_order ["op <= :: [int, int] => bool"]
  3311     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3312 
  3313 Typically, the constant `partial_order.less' is created by a
  3314 definition specification element in the context of locale
  3315 partial_order.
  3316 
  3317 * Method "induct": improved internal context management to support
  3318 local fixes and defines on-the-fly. Thus explicit meta-level
  3319 connectives !!  and ==> are rarely required anymore in inductive goals
  3320 (using object-logic connectives for this purpose has been long
  3321 obsolete anyway). Common proof patterns are explained in
  3322 src/HOL/Induct/Common_Patterns.thy, see also
  3323 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3324 examples.
  3325 
  3326 * Method "induct": improved handling of simultaneous goals. Instead of
  3327 introducing object-level conjunction, the statement is now split into
  3328 several conclusions, while the corresponding symbolic cases are nested
  3329 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3330 see src/HOL/Induct/Common_Patterns.thy, for example.
  3331 
  3332 * Method "induct": mutual induction rules are now specified as a list
  3333 of rule sharing the same induction cases. HOL packages usually provide
  3334 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3335 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3336 mutual induction rules differently, i.e. like this:
  3337 
  3338   (induct rule: foo_bar.inducts)
  3339   (induct set: foo bar)
  3340   (induct pred: foo bar)
  3341   (induct type: foo bar)
  3342 
  3343 The ML function ProjectRule.projections turns old-style rules into the
  3344 new format.
  3345 
  3346 * Method "coinduct": dual of induction, see
  3347 src/HOL/Library/Coinductive_List.thy for various examples.
  3348 
  3349 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3350 considered a legacy feature.
  3351 
  3352 * Attribute "symmetric" produces result with standardized schematic
  3353 variables (index 0).  Potential INCOMPATIBILITY.
  3354 
  3355 * Simplifier: by default the simplifier trace only shows top level
  3356 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3357 default. Thus there is less danger of being flooded by the trace. The
  3358 trace indicates where parts have been suppressed.
  3359   
  3360 * Provers/classical: removed obsolete classical version of elim_format
  3361 attribute; classical elim/dest rules are now treated uniformly when
  3362 manipulating the claset.
  3363 
  3364 * Provers/classical: stricter checks to ensure that supplied intro,
  3365 dest and elim rules are well-formed; dest and elim rules must have at
  3366 least one premise.
  3367 
  3368 * Provers/classical: attributes dest/elim/intro take an optional
  3369 weight argument for the rule (just as the Pure versions).  Weights are
  3370 ignored by automated tools, but determine the search order of single
  3371 rule steps.
  3372 
  3373 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3374 where the body does not mention the bound variable.  Note that dummy
  3375 patterns implicitly depend on their context of bounds, which makes
  3376 "{_. _}" match any set comprehension as expected.  Potential
  3377 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3378 constant "_idtdummy" in the binding position.
  3379 
  3380 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3381 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3382 for example "A -> B" => "Pi A (%_. B)".
  3383 
  3384 * Pure: 'class_deps' command visualizes the subclass relation, using
  3385 the graph browser tool.
  3386 
  3387 * Pure: 'print_theory' now suppresses certain internal declarations by
  3388 default; use '!' option for full details.
  3389 
  3390 
  3391 *** HOL ***
  3392 
  3393 * Method "metis" proves goals by applying the Metis general-purpose
  3394 resolution prover (see also http://gilith.com/software/metis/).
  3395 Examples are in the directory MetisExamples.  WARNING: the
  3396 Isabelle/HOL-Metis integration does not yet work properly with
  3397 multi-threading.
  3398   
  3399 * Command 'sledgehammer' invokes external automatic theorem provers as
  3400 background processes.  It generates calls to the "metis" method if
  3401 successful. These can be pasted into the proof.  Users do not have to
  3402 wait for the automatic provers to return.  WARNING: does not really
  3403 work with multi-threading.
  3404 
  3405 * New "auto_quickcheck" feature tests outermost goal statements for
  3406 potential counter-examples.  Controlled by ML references
  3407 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3408 5000 milliseconds).  Fails silently if statements is outside of
  3409 executable fragment, or any other codgenerator problem occurs.
  3410 
  3411 * New constant "undefined" with axiom "undefined x = undefined".
  3412 
  3413 * Added class "HOL.eq", allowing for code generation with polymorphic
  3414 equality.
  3415 
  3416 * Some renaming of class constants due to canonical name prefixing in
  3417 the new 'class' package:
  3418 
  3419     HOL.abs ~> HOL.abs_class.abs
  3420     HOL.divide ~> HOL.divide_class.divide
  3421     0 ~> HOL.zero_class.zero
  3422     1 ~> HOL.one_class.one
  3423     op + ~> HOL.plus_class.plus
  3424     op - ~> HOL.minus_class.minus
  3425     uminus ~> HOL.minus_class.uminus
  3426     op * ~> HOL.times_class.times
  3427     op < ~> HOL.ord_class.less
  3428     op <= > HOL.ord_class.less_eq
  3429     Nat.power ~> Power.power_class.power
  3430     Nat.size ~> Nat.size_class.size
  3431     Numeral.number_of ~> Numeral.number_class.number_of
  3432     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3433     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3434     Orderings.min ~> Orderings.ord_class.min
  3435     Orderings.max ~> Orderings.ord_class.max
  3436     Divides.op div ~> Divides.div_class.div
  3437     Divides.op mod ~> Divides.div_class.mod
  3438     Divides.op dvd ~> Divides.div_class.dvd
  3439 
  3440 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3441 
  3442 a) User-defined constants using any of the names "plus", "minus",
  3443 "times", "less" or "less_eq". The standard syntax translations for
  3444 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3445 names.
  3446 
  3447 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3448 INCOMPATIBILITY: use more specific names.
  3449 
  3450 c) Permutative equations (e.g. "a + b = b + a")
  3451 Since the change of names also changes the order of terms, permutative
  3452 rewrite rules may get applied in a different order. Experience shows
  3453 that this is rarely the case (only two adaptions in the whole Isabelle
  3454 distribution).  INCOMPATIBILITY: rewrite proofs
  3455 
  3456 d) ML code directly refering to constant names
  3457 This in general only affects hand-written proof tactics, simprocs and
  3458 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3459 Consider using @{const_name} antiquotation.
  3460 
  3461 * New class "default" with associated constant "default".
  3462 
  3463 * Function "sgn" is now overloaded and available on int, real, complex
  3464 (and other numeric types), using class "sgn".  Two possible defs of
  3465 sgn are given as equational assumptions in the classes sgn_if and
  3466 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3467 INCOMPATIBILITY.
  3468 
  3469 * Locale "partial_order" now unified with class "order" (cf. theory
  3470 Orderings), added parameter "less".  INCOMPATIBILITY.
  3471 
  3472 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3473 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3474 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3475 
  3476 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3477 changed order of proof goals in instance proofs.
  3478 
  3479 * The transitivity reasoner for partial and linear orders is set up
  3480 for classes "order" and "linorder".  Instances of the reasoner are available
  3481 in all contexts importing or interpreting the corresponding locales.
  3482 Method "order" invokes the reasoner separately; the reasoner
  3483 is also integrated with the Simplifier as a solver.  Diagnostic
  3484 command 'print_orders' shows the available instances of the reasoner
  3485 in the current context.
  3486 
  3487 * Localized monotonicity predicate in theory "Orderings"; integrated
  3488 lemmas max_of_mono and min_of_mono with this predicate.
  3489 INCOMPATIBILITY.
  3490 
  3491 * Formulation of theorem "dense" changed slightly due to integration
  3492 with new class dense_linear_order.
  3493 
  3494 * Uniform lattice theory development in HOL.
  3495 
  3496     constants "meet" and "join" now named "inf" and "sup"
  3497     constant "Meet" now named "Inf"
  3498 
  3499     classes "meet_semilorder" and "join_semilorder" now named
  3500       "lower_semilattice" and "upper_semilattice"
  3501     class "lorder" now named "lattice"
  3502     class "comp_lat" now named "complete_lattice"
  3503 
  3504     Instantiation of lattice classes allows explicit definitions
  3505     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3506 
  3507   INCOMPATIBILITY.  Theorem renames:
  3508 
  3509     meet_left_le            ~> inf_le1
  3510     meet_right_le           ~> inf_le2
  3511     join_left_le            ~> sup_ge1
  3512     join_right_le           ~> sup_ge2
  3513     meet_join_le            ~> inf_sup_ord
  3514     le_meetI                ~> le_infI
  3515     join_leI                ~> le_supI
  3516     le_meet                 ~> le_inf_iff
  3517     le_join                 ~> ge_sup_conv
  3518     meet_idempotent         ~> inf_idem
  3519     join_idempotent         ~> sup_idem
  3520     meet_comm               ~> inf_commute
  3521     join_comm               ~> sup_commute
  3522     meet_leI1               ~> le_infI1
  3523     meet_leI2               ~> le_infI2
  3524     le_joinI1               ~> le_supI1
  3525     le_joinI2               ~> le_supI2
  3526     meet_assoc              ~> inf_assoc
  3527     join_assoc              ~> sup_assoc
  3528     meet_left_comm          ~> inf_left_commute
  3529     meet_left_idempotent    ~> inf_left_idem
  3530     join_left_comm          ~> sup_left_commute
  3531     join_left_idempotent    ~> sup_left_idem
  3532     meet_aci                ~> inf_aci
  3533     join_aci                ~> sup_aci
  3534     le_def_meet             ~> le_iff_inf
  3535     le_def_join             ~> le_iff_sup
  3536     join_absorp2            ~> sup_absorb2
  3537     join_absorp1            ~> sup_absorb1
  3538     meet_absorp1            ~> inf_absorb1
  3539     meet_absorp2            ~> inf_absorb2
  3540     meet_join_absorp        ~> inf_sup_absorb
  3541     join_meet_absorp        ~> sup_inf_absorb
  3542     distrib_join_le         ~> distrib_sup_le
  3543     distrib_meet_le         ~> distrib_inf_le
  3544 
  3545     add_meet_distrib_left   ~> add_inf_distrib_left
  3546     add_join_distrib_left   ~> add_sup_distrib_left
  3547     is_join_neg_meet        ~> is_join_neg_inf
  3548     is_meet_neg_join        ~> is_meet_neg_sup
  3549     add_meet_distrib_right  ~> add_inf_distrib_right
  3550     add_join_distrib_right  ~> add_sup_distrib_right
  3551     add_meet_join_distribs  ~> add_sup_inf_distribs
  3552     join_eq_neg_meet        ~> sup_eq_neg_inf
  3553     meet_eq_neg_join        ~> inf_eq_neg_sup
  3554     add_eq_meet_join        ~> add_eq_inf_sup
  3555     meet_0_imp_0            ~> inf_0_imp_0
  3556     join_0_imp_0            ~> sup_0_imp_0
  3557     meet_0_eq_0             ~> inf_0_eq_0
  3558     join_0_eq_0             ~> sup_0_eq_0
  3559     neg_meet_eq_join        ~> neg_inf_eq_sup
  3560     neg_join_eq_meet        ~> neg_sup_eq_inf
  3561     join_eq_if              ~> sup_eq_if
  3562 
  3563     mono_meet               ~> mono_inf
  3564     mono_join               ~> mono_sup
  3565     meet_bool_eq            ~> inf_bool_eq
  3566     join_bool_eq            ~> sup_bool_eq
  3567     meet_fun_eq             ~> inf_fun_eq
  3568     join_fun_eq             ~> sup_fun_eq
  3569     meet_set_eq             ~> inf_set_eq
  3570     join_set_eq             ~> sup_set_eq
  3571     meet1_iff               ~> inf1_iff
  3572     meet2_iff               ~> inf2_iff
  3573     meet1I                  ~> inf1I
  3574     meet2I                  ~> inf2I
  3575     meet1D1                 ~> inf1D1
  3576     meet2D1                 ~> inf2D1
  3577     meet1D2                 ~> inf1D2
  3578     meet2D2                 ~> inf2D2
  3579     meet1E                  ~> inf1E
  3580     meet2E                  ~> inf2E
  3581     join1_iff               ~> sup1_iff
  3582     join2_iff               ~> sup2_iff
  3583     join1I1                 ~> sup1I1
  3584     join2I1                 ~> sup2I1
  3585     join1I1                 ~> sup1I1
  3586     join2I2                 ~> sup1I2
  3587     join1CI                 ~> sup1CI
  3588     join2CI                 ~> sup2CI
  3589     join1E                  ~> sup1E
  3590     join2E                  ~> sup2E
  3591 
  3592     is_meet_Meet            ~> is_meet_Inf
  3593     Meet_bool_def           ~> Inf_bool_def
  3594     Meet_fun_def            ~> Inf_fun_def
  3595     Meet_greatest           ~> Inf_greatest
  3596     Meet_lower              ~> Inf_lower
  3597     Meet_set_def            ~> Inf_set_def
  3598 
  3599     Sup_def                 ~> Sup_Inf
  3600     Sup_bool_eq             ~> Sup_bool_def
  3601     Sup_fun_eq              ~> Sup_fun_def
  3602     Sup_set_eq              ~> Sup_set_def
  3603 
  3604     listsp_meetI            ~> listsp_infI
  3605     listsp_meet_eq          ~> listsp_inf_eq
  3606 
  3607     meet_min                ~> inf_min
  3608     join_max                ~> sup_max
  3609 
  3610 * Added syntactic class "size"; overloaded constant "size" now has
  3611 type "'a::size ==> bool"
  3612 
  3613 * Internal reorganisation of `size' of datatypes: size theorems
  3614 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3615 simplification rules by default!); theorems "prod.size" now named
  3616 "*.size".
  3617 
  3618 * Class "div" now inherits from class "times" rather than "type".
  3619 INCOMPATIBILITY.
  3620 
  3621 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3622 Linorder etc.  have disappeared; operations defined in terms of
  3623 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3624 
  3625 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3626 
  3627 * HOL-Word: New extensive library and type for generic, fixed size
  3628 machine words, with arithemtic, bit-wise, shifting and rotating
  3629 operations, reflection into int, nat, and bool lists, automation for
  3630 linear arithmetic (by automatic reflection into nat or int), including
  3631 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3632 arithmetic type classes, supporting automatic simplification of
  3633 numerals on all operations.
  3634 
  3635 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3636 
  3637 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3638 
  3639 * Code generator library theories:
  3640   - Code_Integer represents HOL integers by big integer literals in target
  3641     languages.
  3642   - Code_Char represents HOL characters by character literals in target
  3643     languages.
  3644   - Code_Char_chr like Code_Char, but also offers treatment of character
  3645     codes; includes Code_Integer.
  3646   - Executable_Set allows to generate code for finite sets using lists.
  3647   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3648     denominator).
  3649   - Executable_Real implements a subset of real numbers, namly those
  3650     representable by rational numbers.
  3651   - Efficient_Nat implements natural numbers by integers, which in general will
  3652     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3653     includes Code_Integer.
  3654   - Code_Index provides an additional datatype index which is mapped to
  3655     target-language built-in integers.
  3656   - Code_Message provides an additional datatype message_string which is isomorphic to
  3657     strings; messages are mapped to target-language strings.
  3658 
  3659 * New package for inductive predicates
  3660 
  3661   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3662 
  3663     inductive
  3664       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3665       for z_1 :: U_1 and ... and z_n :: U_m
  3666     where
  3667       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3668     | ...
  3669 
  3670   with full support for type-inference, rather than
  3671 
  3672     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3673 
  3674     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3675     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3676 
  3677     inductive "s z_1 ... z_m"
  3678     intros
  3679       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3680       ...
  3681 
  3682   For backward compatibility, there is a wrapper allowing inductive
  3683   sets to be defined with the new package via
  3684 
  3685     inductive_set
  3686       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3687       for z_1 :: U_1 and ... and z_n :: U_m
  3688     where
  3689       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3690     | ...
  3691 
  3692   or
  3693 
  3694     inductive_set
  3695       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3696       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3697       for z_1 :: U_1 and ... and z_n :: U_m
  3698     where
  3699       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3700     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3701     | ...
  3702 
  3703   if the additional syntax "p ..." is required.
  3704 
  3705   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3706   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3707 
  3708   INCOMPATIBILITIES:
  3709 
  3710   - Since declaration and definition of inductive sets or predicates
  3711     is no longer separated, abbreviations involving the newly
  3712     introduced sets or predicates must be specified together with the
  3713     introduction rules after the 'where' keyword (see above), rather
  3714     than before the actual inductive definition.
  3715 
  3716   - The variables in induction and elimination rules are now
  3717     quantified in the order of their occurrence in the introduction
  3718     rules, rather than in alphabetical order. Since this may break
  3719     some proofs, these proofs either have to be repaired, e.g. by
  3720     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3721     statements of the form
  3722 
  3723       case (rule_i a_i_1 ... a_i_{k_i})
  3724 
  3725     or the old order of quantification has to be restored by explicitly adding
  3726     meta-level quantifiers in the introduction rules, i.e.
  3727 
  3728       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3729 
  3730   - The format of the elimination rules is now
  3731 
  3732       p z_1 ... z_m x_1 ... x_n ==>
  3733         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3734         ==> ... ==> P
  3735 
  3736     for predicates and
  3737 
  3738       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3739         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3740         ==> ... ==> P
  3741 
  3742     for sets rather than
  3743 
  3744       x : s z_1 ... z_m ==>
  3745         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3746         ==> ... ==> P
  3747 
  3748     This may require terms in goals to be expanded to n-tuples
  3749     (e.g. using case_tac or simplification with the split_paired_all
  3750     rule) before the above elimination rule is applicable.
  3751 
  3752   - The elimination or case analysis rules for (mutually) inductive
  3753     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3754     list of rules "p_1_..._p_k.elims" is no longer available.
  3755 
  3756 * New package "function"/"fun" for general recursive functions,
  3757 supporting mutual and nested recursion, definitions in local contexts,
  3758 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3759 for small examples, and the separate tutorial on the function
  3760 package. The old recdef "package" is still available as before, but
  3761 users are encouraged to use the new package.
  3762 
  3763 * Method "lexicographic_order" automatically synthesizes termination
  3764 relations as lexicographic combinations of size measures. 
  3765 
  3766 * Case-expressions allow arbitrary constructor-patterns (including
  3767 "_") and take their order into account, like in functional
  3768 programming.  Internally, this is translated into nested
  3769 case-expressions; missing cases are added and mapped to the predefined
  3770 constant "undefined". In complicated cases printing may no longer show
  3771 the original input but the internal form. Lambda-abstractions allow
  3772 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3773 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3774 variable.
  3775 
  3776 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3777 is an abbreviation for "of_nat :: nat => int". The simplification
  3778 rules for "of_nat" have been changed to work like "int" did
  3779 previously.  Potential INCOMPATIBILITY:
  3780   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3781   - of_nat_diff and of_nat_mult are no longer default simp rules
  3782 
  3783 * Method "algebra" solves polynomial equations over (semi)rings using
  3784 Groebner bases. The (semi)ring structure is defined by locales and the
  3785 tool setup depends on that generic context. Installing the method for
  3786 a specific type involves instantiating the locale and possibly adding
  3787 declarations for computation on the coefficients.  The method is
  3788 already instantiated for natural numbers and for the axiomatic class
  3789 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3790 CALCULEMUS 2007 for the general principles underlying this
  3791 architecture of context-aware proof-tools.
  3792 
  3793 * Method "ferrack" implements quantifier elimination over
  3794 special-purpose dense linear orders using locales (analogous to
  3795 "algebra"). The method is already installed for class
  3796 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3797 rat, etc.
  3798 
  3799 * Former constant "List.op @" now named "List.append".  Use ML
  3800 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3801 circumvent possible incompatibilities when working on ML level.
  3802 
  3803 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3804 
  3805 * New function listsum :: 'a list => 'a for arbitrary monoids.
  3806 Special syntax: "SUM x <- xs. f x" (and latex variants)
  3807 
  3808 * New syntax for Haskell-like list comprehension (input only), eg.
  3809 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  3810 
  3811 * The special syntax for function "filter" has changed from [x :
  3812 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  3813 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  3814 
  3815 * [a..b] is now defined for arbitrary linear orders.  It used to be
  3816 defined on nat only, as an abbreviation for [a..<Suc b]
  3817 INCOMPATIBILITY.
  3818 
  3819 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  3820 
  3821 * New functions "sorted" and "sort" in src/HOL/List.thy.
  3822 
  3823 * New lemma collection field_simps (an extension of ring_simps) for
  3824 manipulating (in)equations involving division. Multiplies with all
  3825 denominators that can be proved to be non-zero (in equations) or
  3826 positive/negative (in inequations).
  3827 
  3828 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  3829 have been improved and renamed to ring_simps, group_simps and
  3830 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  3831 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  3832 
  3833 * Theory Library/Commutative_Ring: switched from recdef to function
  3834 package; constants add, mul, pow now curried.  Infix syntax for
  3835 algebraic operations.
  3836 
  3837 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  3838 INCOMPATIBILITY.
  3839 
  3840 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  3841 INCOMPATIBILITY.
  3842 
  3843 * HOL/records: generalised field-update to take a function on the
  3844 field rather than the new value: r(|A := x|) is translated to A_update
  3845 (K x) r The K-combinator that is internally used is called K_record.
  3846 INCOMPATIBILITY: Usage of the plain update functions has to be
  3847 adapted.
  3848  
  3849 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  3850 * x = 0, which are required for a semiring.  Richer structures do not
  3851 inherit from semiring_0 anymore, because this property is a theorem
  3852 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  3853 there is more to prove, but this is mostly trivial.
  3854 
  3855 * Class "recpower" is generalized to arbitrary monoids, not just
  3856 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  3857 commutativity or semiring properties additionally.
  3858 
  3859 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  3860 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  3861 better use 'abbreviation'.
  3862 
  3863 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  3864 
  3865 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  3866 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  3867 significant changes for setting up numeral syntax for types:
  3868   - New constants Numeral.pred and Numeral.succ instead
  3869       of former Numeral.bin_pred and Numeral.bin_succ.
  3870   - Use integer operations instead of bin_add, bin_mult and so on.
  3871   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  3872   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  3873 
  3874 See src/HOL/Integ/IntArith.thy for an example setup.
  3875 
  3876 * Command 'normal_form' computes the normal form of a term that may
  3877 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  3878 produces ``[b, c, a]'' (without proof).  This command is suitable for
  3879 heavy-duty computations because the functions are compiled to ML
  3880 first.  Correspondingly, a method "normalization" is provided.  See
  3881 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  3882 
  3883 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  3884 25 like -->); output depends on the "iff" print_mode, the default is
  3885 "A = B" (with priority 50).
  3886 
  3887 * Relations less (<) and less_eq (<=) are also available on type bool.
  3888 Modified syntax to disallow nesting without explicit parentheses,
  3889 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  3890 INCOMPATIBILITY.
  3891 
  3892 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  3893 
  3894 * Relation composition operator "op O" now has precedence 75 and binds
  3895 stronger than union and intersection. INCOMPATIBILITY.
  3896 
  3897 * The old set interval syntax "{m..n(}" (and relatives) has been
  3898 removed.  Use "{m..<n}" (and relatives) instead.
  3899 
  3900 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  3901 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  3902 ``declare [[simproc del: neq]]''.
  3903 
  3904 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  3905 True/False.
  3906 
  3907 * Theorem Cons_eq_map_conv no longer declared as "simp".
  3908 
  3909 * Theorem setsum_mult renamed to setsum_right_distrib.
  3910 
  3911 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  3912 ``rule'' method.
  3913 
  3914 * Reimplemented methods "sat" and "satx", with several improvements:
  3915 goals no longer need to be stated as "<prems> ==> False", equivalences
  3916 (i.e. "=" on type bool) are handled, variable names of the form
  3917 "lit_<n>" are no longer reserved, significant speedup.
  3918 
  3919 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  3920 zChaff is still supported as well.
  3921 
  3922 * 'inductive' and 'datatype': provide projections of mutual rules,
  3923 bundled as foo_bar.inducts;
  3924 
  3925 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  3926 Library.
  3927 
  3928 * Library: moved theory Accessible_Part to main HOL.
  3929 
  3930 * Library: added theory Coinductive_List of potentially infinite lists
  3931 as greatest fixed-point.
  3932 
  3933 * Library: added theory AssocList which implements (finite) maps as
  3934 association lists.
  3935 
  3936 * Method "evaluation" solves goals (i.e. a boolean expression)
  3937 efficiently by compiling it to ML.  The goal is "proved" (via an
  3938 oracle) if it evaluates to True.
  3939 
  3940 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  3941 also when invoked by the simplifier.  This results in the Simplifier
  3942 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  3943 Configuration option fast_arith_split_limit=0 recovers the old
  3944 behavior.
  3945 
  3946 * Support for hex (0x20) and binary (0b1001) numerals.
  3947 
  3948 * New method: reify eqs (t), where eqs are equations for an
  3949 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  3950 parameter, computes a term s::'b and a list xs::'a list and proves the
  3951 theorem I xs s = t. This is also known as reification or quoting. The
  3952 resulting theorem is applied to the subgoal to substitute t with I xs
  3953 s.  If t is omitted, the subgoal itself is reified.
  3954 
  3955 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  3956 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  3957 where f is supposed to be a computable function (in the sense of code
  3958 generattion). The method uses reify to compute s and xs as above then
  3959 applies corr_thm and uses normalization by evaluation to "prove" f s =
  3960 r and finally gets the theorem t = r, which is again applied to the
  3961 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  3962 
  3963 * Reflection: Automatic reification now handels binding, an example is
  3964 available in src/HOL/ex/ReflectionEx.thy
  3965 
  3966 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  3967 command 'statespace' that is similar to 'record', but introduces an
  3968 abstract specification based on the locale infrastructure instead of
  3969 HOL types.  This leads to extra flexibility in composing state spaces,
  3970 in particular multiple inheritance and renaming of components.
  3971 
  3972 
  3973 *** HOL-Complex ***
  3974 
  3975 * Hyperreal: Functions root and sqrt are now defined on negative real
  3976 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  3977 Nonnegativity side conditions have been removed from many lemmas, so
  3978 that more subgoals may now be solved by simplification; potential
  3979 INCOMPATIBILITY.
  3980 
  3981 * Real: new type classes formalize real normed vector spaces and
  3982 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  3983 and norm :: 'a => real.
  3984 
  3985 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  3986 reals into other types. The overloaded constant Reals :: 'a set is now
  3987 defined as range of_real; potential INCOMPATIBILITY.
  3988 
  3989 * Real: proper support for ML code generation, including 'quickcheck'.
  3990 Reals are implemented as arbitrary precision rationals.
  3991 
  3992 * Hyperreal: Several constants that previously worked only for the
  3993 reals have been generalized, so they now work over arbitrary vector
  3994 spaces. Type annotations may need to be added in some cases; potential
  3995 INCOMPATIBILITY.
  3996 
  3997   Infinitesimal  :: ('a::real_normed_vector) star set
  3998   HFinite        :: ('a::real_normed_vector) star set
  3999   HInfinite      :: ('a::real_normed_vector) star set
  4000   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4001   monad          :: ('a::real_normed_vector) star => 'a star set
  4002   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4003   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4004   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4005   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4006   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4007   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4008   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4009   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4010   sgn            :: 'a::real_normed_vector => 'a
  4011   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4012 
  4013 * Complex: Some complex-specific constants are now abbreviations for
  4014 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4015 hnorm.  Other constants have been entirely removed in favor of the
  4016 polymorphic versions (INCOMPATIBILITY):
  4017 
  4018   approx        <-- capprox
  4019   HFinite       <-- CFinite
  4020   HInfinite     <-- CInfinite
  4021   Infinitesimal <-- CInfinitesimal
  4022   monad         <-- cmonad
  4023   galaxy        <-- cgalaxy
  4024   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4025   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4026   (ns)deriv     <-- (ns)cderiv
  4027 
  4028 
  4029 *** HOL-Algebra ***
  4030 
  4031 * Formalisation of ideals and the quotient construction over rings.
  4032 
  4033 * Order and lattice theory no longer based on records.
  4034 INCOMPATIBILITY.
  4035 
  4036 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4037 greatest_closed.  INCOMPATIBILITY.
  4038 
  4039 * Method algebra is now set up via an attribute.  For examples see
  4040 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4041 of algebraic structures.
  4042 
  4043 * Renamed theory CRing to Ring.
  4044 
  4045 
  4046 *** HOL-Nominal ***
  4047 
  4048 * Substantial, yet incomplete support for nominal datatypes (binding
  4049 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4050 src/HOL/Nominal/Examples.  Prospective users should consult
  4051 http://isabelle.in.tum.de/nominal/
  4052 
  4053 
  4054 *** ML ***
  4055 
  4056 * ML basics: just one true type int, which coincides with IntInf.int
  4057 (even on SML/NJ).
  4058 
  4059 * ML within Isar: antiquotations allow to embed statically-checked
  4060 formal entities in the source, referring to the context available at
  4061 compile-time.  For example:
  4062 
  4063 ML {* @{sort "{zero,one}"} *}
  4064 ML {* @{typ "'a => 'b"} *}
  4065 ML {* @{term "%x. x"} *}
  4066 ML {* @{prop "x == y"} *}
  4067 ML {* @{ctyp "'a => 'b"} *}
  4068 ML {* @{cterm "%x. x"} *}
  4069 ML {* @{cprop "x == y"} *}
  4070 ML {* @{thm asm_rl} *}
  4071 ML {* @{thms asm_rl} *}
  4072 ML {* @{type_name c} *}
  4073 ML {* @{type_syntax c} *}
  4074 ML {* @{const_name c} *}
  4075 ML {* @{const_syntax c} *}
  4076 ML {* @{context} *}
  4077 ML {* @{theory} *}
  4078 ML {* @{theory Pure} *}
  4079 ML {* @{theory_ref} *}
  4080 ML {* @{theory_ref Pure} *}
  4081 ML {* @{simpset} *}
  4082 ML {* @{claset} *}
  4083 ML {* @{clasimpset} *}
  4084 
  4085 The same works for sources being ``used'' within an Isar context.
  4086 
  4087 * ML in Isar: improved error reporting; extra verbosity with
  4088 ML_Context.trace enabled.
  4089 
  4090 * Pure/General/table.ML: the join operations now works via exceptions
  4091 DUP/SAME instead of type option. This is simpler in simple cases, and
  4092 admits slightly more efficient complex applications.
  4093 
  4094 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4095 use Context.generic instead of just theory.
  4096 
  4097 * Pure: datatype Context.generic joins theory/Proof.context and
  4098 provides some facilities for code that works in either kind of
  4099 context, notably GenericDataFun for uniform theory and proof data.
  4100 
  4101 * Pure: simplified internal attribute type, which is now always
  4102 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4103 local (Proof.context) attributes have been discontinued, while
  4104 minimizing code duplication. Thm.rule_attribute and
  4105 Thm.declaration_attribute build canonical attributes; see also structure
  4106 Context for further operations on Context.generic, notably
  4107 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4108 declarations and definitions.
  4109 
  4110 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4111 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4112 init only required for impure data. INCOMPATIBILITY: empty really need
  4113 to be empty (no dependencies on theory content!)
  4114 
  4115 * Pure/kernel: consts certification ignores sort constraints given in
  4116 signature declarations. (This information is not relevant to the
  4117 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4118 potential INCOMPATIBILITY.
  4119 
  4120 * Pure: axiomatic type classes are now purely definitional, with
  4121 explicit proofs of class axioms and super class relations performed
  4122 internally. See Pure/axclass.ML for the main internal interfaces --
  4123 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4124 AxClass.axiomatize_class/classrel/arity supersede
  4125 Sign.add_classes/classrel/arities.
  4126 
  4127 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4128 global/local versions on theory vs. Proof.context have been
  4129 discontinued; Attrib.syntax and Method.syntax have been adapted
  4130 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4131 attributes, methods, etc.
  4132 
  4133 * Pure: several functions of signature "... -> theory -> theory * ..."
  4134 have been reoriented to "... -> theory -> ... * theory" in order to
  4135 allow natural usage in combination with the ||>, ||>>, |-> and
  4136 fold_map combinators.
  4137 
  4138 * Pure: official theorem names (closed derivations) and additional
  4139 comments (tags) are now strictly separate.  Name hints -- which are
  4140 maintained as tags -- may be attached any time without affecting the
  4141 derivation.
  4142 
  4143 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4144 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4145 achieve the old behaviour.
  4146 
  4147 * Pure: the "Goal" constant is now called "prop", supporting a
  4148 slightly more general idea of ``protecting'' meta-level rule
  4149 statements.
  4150 
  4151 * Pure: Logic.(un)varify only works in a global context, which is now
  4152 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4153 Logic.legacy_(un)varify as temporary workaround.
  4154 
  4155 * Pure: structure Name provides scalable operations for generating
  4156 internal variable names, notably Name.variants etc.  This replaces
  4157 some popular functions from term.ML:
  4158 
  4159   Term.variant		->  Name.variant
  4160   Term.variantlist	->  Name.variant_list
  4161   Term.invent_names	->  Name.invent_list
  4162 
  4163 Note that low-level renaming rarely occurs in new code -- operations
  4164 from structure Variable are used instead (see below).
  4165 
  4166 * Pure: structure Variable provides fundamental operations for proper
  4167 treatment of fixed/schematic variables in a context.  For example,
  4168 Variable.import introduces fixes for schematics of given facts and
  4169 Variable.export reverses the effect (up to renaming) -- this replaces
  4170 various freeze_thaw operations.
  4171 
  4172 * Pure: structure Goal provides simple interfaces for
  4173 init/conclude/finish and tactical prove operations (replacing former
  4174 Tactic.prove).  Goal.prove is the canonical way to prove results
  4175 within a given context; Goal.prove_global is a degraded version for
  4176 theory level goals, including a global Drule.standard.  Note that
  4177 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4178 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4179 in a locale context).
  4180 
  4181 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4182 and type checking (Syntax.check_term etc.), with common combinations
  4183 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4184 which are considered legacy and await removal.
  4185 
  4186 * Pure/Syntax: generic interfaces for type unchecking
  4187 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4188 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4189 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4190 available for convenience, but refer to the very same operations using
  4191 a mere theory instead of a full context.
  4192 
  4193 * Isar: simplified treatment of user-level errors, using exception
  4194 ERROR of string uniformly.  Function error now merely raises ERROR,
  4195 without any side effect on output channels.  The Isar toplevel takes
  4196 care of proper display of ERROR exceptions.  ML code may use plain
  4197 handle/can/try; cat_error may be used to concatenate errors like this:
  4198 
  4199   ... handle ERROR msg => cat_error msg "..."
  4200 
  4201 Toplevel ML code (run directly or through the Isar toplevel) may be
  4202 embedded into the Isar toplevel with exception display/debug like
  4203 this:
  4204 
  4205   Isar.toplevel (fn () => ...)
  4206 
  4207 INCOMPATIBILITY, removed special transform_error facilities, removed
  4208 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4209 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4210 -- use plain ERROR instead.
  4211 
  4212 * Isar: theory setup now has type (theory -> theory), instead of a
  4213 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4214 
  4215 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4216 ProofContext.debug/verbose flags.
  4217 
  4218 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4219 theory before entering a proof state.  Transactions now always see a
  4220 quasi-functional intermediate checkpoint, both in interactive and
  4221 batch mode.
  4222 
  4223 * Isar: simplified interfaces for outer syntax.  Renamed
  4224 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4225 OuterSyntax.add_parsers -- this functionality is now included in
  4226 OuterSyntax.command etc.  INCOMPATIBILITY.
  4227 
  4228 * Simplifier: the simpset of a running simplification process now
  4229 contains a proof context (cf. Simplifier.the_context), which is the
  4230 very context that the initial simpset has been retrieved from (by
  4231 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4232 (solver, looper etc.) may depend on arbitrary proof data.
  4233 
  4234 * Simplifier.inherit_context inherits the proof context (plus the
  4235 local bounds) of the current simplification process; any simproc
  4236 etc. that calls the Simplifier recursively should do this!  Removed
  4237 former Simplifier.inherit_bounds, which is already included here --
  4238 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4239 specify an explicit context using Simplifier.context/theory_context.
  4240 
  4241 * Simplifier/Classical Reasoner: more abstract interfaces
  4242 change_simpset/claset for modifying the simpset/claset reference of a
  4243 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4244 INCOMPATIBILITY.
  4245 
  4246 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4247 "Trueprop" etc.
  4248 
  4249 
  4250 *** System ***
  4251 
  4252 * settings: the default heap location within ISABELLE_HOME_USER now
  4253 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4254 Isabelle installations.
  4255 
  4256 * isabelle-process: option -S (secure mode) disables some critical
  4257 operations, notably runtime compilation and evaluation of ML source
  4258 code.
  4259 
  4260 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4261 
  4262 * Support for parallel execution, using native multicore support of
  4263 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4264 independent theories, according to the given theory header
  4265 specifications. The maximum number of worker threads is specified via
  4266 usedir option -M or the "max-threads" setting in Proof General. A
  4267 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4268 to 6 on a 8-core machine.  User-code needs to observe certain
  4269 guidelines for thread-safe programming, see appendix A in the Isar
  4270 Implementation manual.
  4271 
  4272 
  4273 
  4274 New in Isabelle2005 (October 2005)
  4275 ----------------------------------
  4276 
  4277 *** General ***
  4278 
  4279 * Theory headers: the new header syntax for Isar theories is
  4280 
  4281   theory <name>
  4282   imports <theory1> ... <theoryN>
  4283   uses <file1> ... <fileM>
  4284   begin
  4285 
  4286 where the 'uses' part is optional.  The previous syntax
  4287 
  4288   theory <name> = <theory1> + ... + <theoryN>:
  4289 
  4290 will disappear in the next release.  Use isatool fixheaders to convert
  4291 existing theory files.  Note that there is no change in ancient
  4292 non-Isar theories now, but these will disappear soon.
  4293 
  4294 * Theory loader: parent theories can now also be referred to via
  4295 relative and absolute paths.
  4296 
  4297 * Command 'find_theorems' searches for a list of criteria instead of a
  4298 list of constants. Known criteria are: intro, elim, dest, name:string,
  4299 simp:term, and any term. Criteria can be preceded by '-' to select
  4300 theorems that do not match. Intro, elim, dest select theorems that
  4301 match the current goal, name:s selects theorems whose fully qualified
  4302 name contain s, and simp:term selects all simplification rules whose
  4303 lhs match term.  Any other term is interpreted as pattern and selects
  4304 all theorems matching the pattern. Available in ProofGeneral under
  4305 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4306 
  4307   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4308 
  4309 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4310 matching the current goal as introduction rule and not having "HOL."
  4311 in their name (i.e. not being defined in theory HOL).
  4312 
  4313 * Command 'thms_containing' has been discontinued in favour of
  4314 'find_theorems'; INCOMPATIBILITY.
  4315 
  4316 * Communication with Proof General is now 8bit clean, which means that
  4317 Unicode text in UTF-8 encoding may be used within theory texts (both
  4318 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4319 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4320 
  4321   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4322   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4323 
  4324 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4325 Classical Reasoner.  Typical big applications run around 2 times
  4326 faster.
  4327 
  4328 
  4329 *** Document preparation ***
  4330 
  4331 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4332 of raw sources.  Only those symbols that do not require additional
  4333 LaTeX packages (depending on comments in isabellesym.sty) are
  4334 displayed properly, everything else is left verbatim.  isatool display
  4335 and isatool print are used as front ends (these are subject to the
  4336 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4337 
  4338 * Command tags control specific markup of certain regions of text,
  4339 notably folding and hiding.  Predefined tags include "theory" (for
  4340 theory begin and end), "proof" for proof commands, and "ML" for
  4341 commands involving ML code; the additional tags "visible" and
  4342 "invisible" are unused by default.  Users may give explicit tag
  4343 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4344 interpretation of tags is determined by the LaTeX job during document
  4345 preparation: see option -V of isatool usedir, or options -n and -t of
  4346 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4347 \isadroptag.
  4348 
  4349 Several document versions may be produced at the same time via isatool
  4350 usedir (the generated index.html will link all of them).  Typical
  4351 specifications include ''-V document=theory,proof,ML'' to present
  4352 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4353 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4354 these parts without any formal replacement text.  The Isabelle site
  4355 default settings produce ''document'' and ''outline'' versions as
  4356 specified above.
  4357 
  4358 * Several new antiquotations:
  4359 
  4360   @{term_type term} prints a term with its type annotated;
  4361 
  4362   @{typeof term} prints the type of a term;
  4363 
  4364   @{const const} is the same as @{term const}, but checks that the
  4365   argument is a known logical constant;
  4366 
  4367   @{term_style style term} and @{thm_style style thm} print a term or
  4368   theorem applying a "style" to it
  4369 
  4370   @{ML text}
  4371 
  4372 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4373 definitions, equations, inequations etc., 'concl' printing only the
  4374 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4375 to print the specified premise.  TermStyle.add_style provides an ML
  4376 interface for introducing further styles.  See also the "LaTeX Sugar"
  4377 document practical applications.  The ML antiquotation prints
  4378 type-checked ML expressions verbatim.
  4379 
  4380 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4381 and 'text' support optional locale specification '(in loc)', which
  4382 specifies the default context for interpreting antiquotations.  For
  4383 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4384 
  4385 * Option 'locale=NAME' of antiquotations specifies an alternative
  4386 context interpreting the subsequent argument.  For example: @{thm
  4387 [locale=lattice] inf_assoc}.
  4388 
  4389 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4390 a proof context.
  4391 
  4392 * Proper output of antiquotations for theory commands involving a
  4393 proof context (such as 'locale' or 'theorem (in loc) ...').
  4394 
  4395 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4396 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4397 
  4398 * isatool usedir: new option -C (default true) controls whether option
  4399 -D should include a copy of the original document directory; -C false
  4400 prevents unwanted effects such as copying of administrative CVS data.
  4401 
  4402 
  4403 *** Pure ***
  4404 
  4405 * Considerably improved version of 'constdefs' command.  Now performs
  4406 automatic type-inference of declared constants; additional support for
  4407 local structure declarations (cf. locales and HOL records), see also
  4408 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4409 sequential dependencies of definitions within a single 'constdefs'
  4410 section; moreover, the declared name needs to be an identifier.  If
  4411 all fails, consider to fall back on 'consts' and 'defs' separately.
  4412 
  4413 * Improved indexed syntax and implicit structures.  First of all,
  4414 indexed syntax provides a notational device for subscripted
  4415 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4416 expressions.  Secondly, in a local context with structure
  4417 declarations, number indexes \<^sub>n or the empty index (default
  4418 number 1) refer to a certain fixed variable implicitly; option
  4419 show_structs controls printing of implicit structures.  Typical
  4420 applications of these concepts involve record types and locales.
  4421 
  4422 * New command 'no_syntax' removes grammar declarations (and
  4423 translations) resulting from the given syntax specification, which is
  4424 interpreted in the same manner as for the 'syntax' command.
  4425 
  4426 * 'Advanced' translation functions (parse_translation etc.) may depend
  4427 on the signature of the theory context being presently used for
  4428 parsing/printing, see also isar-ref manual.
  4429 
  4430 * Improved 'oracle' command provides a type-safe interface to turn an
  4431 ML expression of type theory -> T -> term into a primitive rule of
  4432 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4433 is already included here); see also FOL/ex/IffExample.thy;
  4434 INCOMPATIBILITY.
  4435 
  4436 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4437 before); "cI" is no longer bound, use "c.intro" instead.
  4438 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4439 axclasses vs. locales.
  4440 
  4441 * Improved internal renaming of symbolic identifiers -- attach primes
  4442 instead of base 26 numbers.
  4443 
  4444 * New flag show_question_marks controls printing of leading question
  4445 marks in schematic variable names.
  4446 
  4447 * In schematic variable names, *any* symbol following \<^isub> or
  4448 \<^isup> is now treated as part of the base name.  For example, the
  4449 following works without printing of awkward ".0" indexes:
  4450 
  4451   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4452     by simp
  4453 
  4454 * Inner syntax includes (*(*nested*) comments*).
  4455 
  4456 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4457 annotations as "(00...)".
  4458 
  4459 * Clear separation of logical types and nonterminals, where the latter
  4460 may only occur in 'syntax' specifications or type abbreviations.
  4461 Before that distinction was only partially implemented via type class
  4462 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4463 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4464 exotic syntax specifications may require further adaption
  4465 (e.g. Cube/Cube.thy).
  4466 
  4467 * Removed obsolete type class "logic", use the top sort {} instead.
  4468 Note that non-logical types should be declared as 'nonterminals'
  4469 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4470 specifications.
  4471 
  4472 * Attributes 'induct' and 'cases': type or set names may now be
  4473 locally fixed variables as well.
  4474 
  4475 * Simplifier: can now control the depth to which conditional rewriting
  4476 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4477 Limit.
  4478 
  4479 * Simplifier: simplification procedures may now take the current
  4480 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4481 interface), which is very useful for calling the Simplifier
  4482 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4483 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4484 low-level mk_simproc no longer applies Logic.varify internally, to
  4485 allow for use in a context of fixed variables.
  4486 
  4487 * thin_tac now works even if the assumption being deleted contains !!
  4488 or ==>.  More generally, erule now works even if the major premise of
  4489 the elimination rule contains !! or ==>.
  4490 
  4491 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4492 
  4493 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4494 from Pure, which contains all common declarations already.  Both
  4495 theories are defined via plain Isabelle/Isar .thy files.
  4496 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4497 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4498 use isatool fixcpure to adapt your theory and ML sources.
  4499 
  4500 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4501 selections of theorems in named facts via index ranges.
  4502 
  4503 * 'print_theorems': in theory mode, really print the difference
  4504 wrt. the last state (works for interactive theory development only),
  4505 in proof mode print all local facts (cf. 'print_facts');
  4506 
  4507 * 'hide': option '(open)' hides only base names.
  4508 
  4509 * More efficient treatment of intermediate checkpoints in interactive
  4510 theory development.
  4511 
  4512 * Code generator is now invoked via code_module (incremental code
  4513 generation) and code_library (modular code generation, ML structures
  4514 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4515 must be quoted when used as identifiers.
  4516 
  4517 * New 'value' command for reading, evaluating and printing terms using
  4518 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4519 quoted when used as identifier.
  4520 
  4521 
  4522 *** Locales ***
  4523 
  4524 * New commands for the interpretation of locale expressions in
  4525 theories (1), locales (2) and proof contexts (3).  These generate
  4526 proof obligations from the expression specification.  After the
  4527 obligations have been discharged, theorems of the expression are added
  4528 to the theory, target locale or proof context.  The synopsis of the
  4529 commands is a follows:
  4530 
  4531   (1) interpretation expr inst
  4532   (2) interpretation target < expr
  4533   (3) interpret expr inst
  4534 
  4535 Interpretation in theories and proof contexts require a parameter
  4536 instantiation of terms from the current context.  This is applied to
  4537 specifications and theorems of the interpreted expression.
  4538 Interpretation in locales only permits parameter renaming through the
  4539 locale expression.  Interpretation is smart in that interpretations
  4540 that are active already do not occur in proof obligations, neither are
  4541 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4542 inspect active interpretations of a particular locale.  For details,
  4543 see the Isar Reference manual.  Examples can be found in
  4544 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4545 
  4546 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4547 'interpret' instead.
  4548 
  4549 * New context element 'constrains' for adding type constraints to
  4550 parameters.
  4551 
  4552 * Context expressions: renaming of parameters with syntax
  4553 redeclaration.
  4554 
  4555 * Locale declaration: 'includes' disallowed.
  4556 
  4557 * Proper static binding of attribute syntax -- i.e. types / terms /
  4558 facts mentioned as arguments are always those of the locale definition
  4559 context, independently of the context of later invocations.  Moreover,
  4560 locale operations (renaming and type / term instantiation) are applied
  4561 to attribute arguments as expected.
  4562 
  4563 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4564 actual attributes; rare situations may require Attrib.attribute to
  4565 embed those attributes into Attrib.src that lack concrete syntax.
  4566 Attribute implementations need to cooperate properly with the static
  4567 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4568 Attrib.XXX_thm etc. already do the right thing without further
  4569 intervention.  Only unusual applications -- such as "where" or "of"
  4570 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4571 on the context and the facts involved -- may have to assign parsed
  4572 values to argument tokens explicitly.
  4573 
  4574 * Changed parameter management in theorem generation for long goal
  4575 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4576 theorem statement in rare situations.
  4577 
  4578 * Locale inspection command 'print_locale' omits notes elements.  Use
  4579 'print_locale!' to have them included in the output.
  4580 
  4581 
  4582 *** Provers ***
  4583 
  4584 * Provers/hypsubst.ML: improved version of the subst method, for
  4585 single-step rewriting: it now works in bound variable contexts. New is
  4586 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4587 rewrite a different subterm than the original subst method, which is
  4588 still available as 'simplesubst'.
  4589 
  4590 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4591 and quasi orders.
  4592 
  4593 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4594 reflexive-transitive closure of relations.
  4595 
  4596 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4597 limit (previously hard-coded with a value of 20) user-definable.
  4598 
  4599 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4600 is peformed already.  Object-logics merely need to finish their
  4601 initial simpset configuration as before.  INCOMPATIBILITY.
  4602 
  4603 
  4604 *** HOL ***
  4605 
  4606 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4607 
  4608   syntax (epsilon)
  4609     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4610 
  4611 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4612 and x-symbol; use option '-m epsilon' to get it actually printed.
  4613 Moreover, the mathematically important symbolic identifier \<epsilon>
  4614 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4615 
  4616 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4617 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4618 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4619 support corresponding Isar calculations.
  4620 
  4621 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4622 instead of ":".
  4623 
  4624 * theory SetInterval: changed the syntax for open intervals:
  4625 
  4626   Old       New
  4627   {..n(}    {..<n}
  4628   {)n..}    {n<..}
  4629   {m..n(}   {m..<n}
  4630   {)m..n}   {m<..n}
  4631   {)m..n(}  {m<..<n}
  4632 
  4633 The old syntax is still supported but will disappear in the next
  4634 release.  For conversion use the following Emacs search and replace
  4635 patterns (these are not perfect but work quite well):
  4636 
  4637   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4638   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4639 
  4640 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4641 equalities in commutative rings; method 'algebra' provides a generic
  4642 interface.
  4643 
  4644 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4645 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4646 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4647 be a tuple pattern.
  4648 
  4649 Some new syntax forms are available:
  4650 
  4651   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4652   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4653   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4654   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4655 
  4656 The latter form "\<Sum>x < k. e" used to be based on a separate
  4657 function "Summation", which has been discontinued.
  4658 
  4659 * theory Finite_Set: in structured induction proofs, the insert case
  4660 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4661 (insert F x)'.
  4662 
  4663 * The 'refute' command has been extended to support a much larger
  4664 fragment of HOL, including axiomatic type classes, constdefs and
  4665 typedefs, inductive datatypes and recursion.
  4666 
  4667 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4668 Requires zChaff with proof generation to be installed.  See
  4669 HOL/ex/SAT_Examples.thy for examples.
  4670 
  4671 * Datatype induction via method 'induct' now preserves the name of the
  4672 induction variable. For example, when proving P(xs::'a list) by
  4673 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4674 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4675 in unstructured proof scripts.
  4676 
  4677 * Reworked implementation of records.  Improved scalability for
  4678 records with many fields, avoiding performance problems for type
  4679 inference. Records are no longer composed of nested field types, but
  4680 of nested extension types. Therefore the record type only grows linear
  4681 in the number of extensions and not in the number of fields.  The
  4682 top-level (users) view on records is preserved.  Potential
  4683 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4684 old record representation. The type generated for a record is called
  4685 <record_name>_ext_type.
  4686 
  4687 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4688 proofs triggered by a record definition or a simproc (if
  4689 quick_and_dirty is enabled).  Definitions of large records can take
  4690 quite long.
  4691 
  4692 New simproc record_upd_simproc for simplification of multiple record
  4693 updates enabled by default.  Moreover, trivial updates are also
  4694 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4695 occasionally, since simplification is more powerful by default.
  4696 
  4697 * typedef: proper support for polymorphic sets, which contain extra
  4698 type-variables in the term.
  4699 
  4700 * Simplifier: automatically reasons about transitivity chains
  4701 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4702 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4703 old proofs break occasionally as simplification may now solve more
  4704 goals than previously.
  4705 
  4706 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4707 present.  Works for all partial orders (class "order"), in particular
  4708 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4709 just like y <= x.
  4710 
  4711 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4712 bound variable or a constant then the let is unfolded.  Otherwise
  4713 first a is simplified to b, and then f b is simplified to g. If
  4714 possible we abstract b from g arriving at "let x = b in h x",
  4715 otherwise we unfold the let and arrive at g.  The simproc can be
  4716 enabled/disabled by the reference use_let_simproc.  Potential
  4717 INCOMPATIBILITY since simplification is more powerful by default.
  4718 
  4719 * Classical reasoning: the meson method now accepts theorems as arguments.
  4720 
  4721 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4722 jobs to provide advice on the provability of subgoals.
  4723 
  4724 * Theory OrderedGroup and Ring_and_Field: various additions and
  4725 improvements to faciliate calculations involving equalities and
  4726 inequalities.
  4727 
  4728 The following theorems have been eliminated or modified
  4729 (INCOMPATIBILITY):
  4730 
  4731   abs_eq             now named abs_of_nonneg
  4732   abs_of_ge_0        now named abs_of_nonneg
  4733   abs_minus_eq       now named abs_of_nonpos
  4734   imp_abs_id         now named abs_of_nonneg
  4735   imp_abs_neg_id     now named abs_of_nonpos
  4736   mult_pos           now named mult_pos_pos
  4737   mult_pos_le        now named mult_nonneg_nonneg
  4738   mult_pos_neg_le    now named mult_nonneg_nonpos
  4739   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4740   mult_neg           now named mult_neg_neg
  4741   mult_neg_le        now named mult_nonpos_nonpos
  4742 
  4743 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4744      
  4745      zero_le_square
  4746      not_square_less_zero 
  4747 
  4748   The following lemmas have been deleted from Real/RealPow:
  4749   
  4750      realpow_zero_zero
  4751      realpow_two
  4752      realpow_less
  4753      zero_le_power
  4754      realpow_two_le
  4755      abs_realpow_two
  4756      realpow_two_abs     
  4757 
  4758 * Theory Parity: added rules for simplifying exponents.
  4759 
  4760 * Theory List:
  4761 
  4762 The following theorems have been eliminated or modified
  4763 (INCOMPATIBILITY):
  4764 
  4765   list_all_Nil       now named list_all.simps(1)
  4766   list_all_Cons      now named list_all.simps(2)
  4767   list_all_conv      now named list_all_iff
  4768   set_mem_eq         now named mem_iff
  4769 
  4770 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4771 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4772 
  4773 
  4774 *** HOL-Complex ***
  4775 
  4776 * Theory RealDef: better support for embedding natural numbers and
  4777 integers in the reals.
  4778 
  4779 The following theorems have been eliminated or modified
  4780 (INCOMPATIBILITY):
  4781 
  4782   exp_ge_add_one_self  now requires no hypotheses
  4783   real_of_int_add      reversed direction of equality (use [symmetric])
  4784   real_of_int_minus    reversed direction of equality (use [symmetric])
  4785   real_of_int_diff     reversed direction of equality (use [symmetric])
  4786   real_of_int_mult     reversed direction of equality (use [symmetric])
  4787 
  4788 * Theory RComplete: expanded support for floor and ceiling functions.
  4789 
  4790 * Theory Ln is new, with properties of the natural logarithm
  4791 
  4792 * Hyperreal: There is a new type constructor "star" for making
  4793 nonstandard types.  The old type names are now type synonyms:
  4794 
  4795   hypreal = real star
  4796   hypnat = nat star
  4797   hcomplex = complex star
  4798 
  4799 * Hyperreal: Many groups of similarly-defined constants have been
  4800 replaced by polymorphic versions (INCOMPATIBILITY):
  4801 
  4802   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4803 
  4804   starset      <-- starsetNat, starsetC
  4805   *s*          <-- *sNat*, *sc*
  4806   starset_n    <-- starsetNat_n, starsetC_n
  4807   *sn*         <-- *sNatn*, *scn*
  4808   InternalSets <-- InternalNatSets, InternalCSets
  4809 
  4810   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  4811   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  4812   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  4813   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  4814   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  4815 
  4816 * Hyperreal: Many type-specific theorems have been removed in favor of
  4817 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  4818 
  4819   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  4820   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  4821   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  4822   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  4823   right_minus <-- hypreal_add_minus
  4824   left_minus <-- {hypreal,hcomplex}_add_minus_left
  4825   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  4826   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  4827   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  4828   mult_1_right <-- hcomplex_mult_one_right
  4829   mult_zero_left <-- hcomplex_mult_zero_left
  4830   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  4831   right_distrib <-- hypnat_add_mult_distrib2
  4832   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  4833   right_inverse <-- hypreal_mult_inverse
  4834   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  4835   order_refl <-- {hypreal,hypnat}_le_refl
  4836   order_trans <-- {hypreal,hypnat}_le_trans
  4837   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  4838   order_less_le <-- {hypreal,hypnat}_less_le
  4839   linorder_linear <-- {hypreal,hypnat}_le_linear
  4840   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  4841   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  4842   add_nonneg_nonneg <-- hypreal_le_add_order
  4843 
  4844 * Hyperreal: Separate theorems having to do with type-specific
  4845 versions of constants have been merged into theorems that apply to the
  4846 new polymorphic constants (INCOMPATIBILITY):
  4847 
  4848   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  4849   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  4850   STAR_Un <-- {STAR,NatStar,STARC}_Un
  4851   STAR_Int <-- {STAR,NatStar,STARC}_Int
  4852   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  4853   STAR_subset <-- {STAR,NatStar,STARC}_subset
  4854   STAR_mem <-- {STAR,NatStar,STARC}_mem
  4855   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  4856   STAR_diff <-- {STAR,STARC}_diff
  4857   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  4858     STARC_hcomplex_of_complex}_image_subset
  4859   starset_n_Un <-- starset{Nat,C}_n_Un
  4860   starset_n_Int <-- starset{Nat,C}_n_Int
  4861   starset_n_Compl <-- starset{Nat,C}_n_Compl
  4862   starset_n_diff <-- starset{Nat,C}_n_diff
  4863   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  4864   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  4865   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  4866   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  4867   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  4868   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  4869   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  4870   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  4871   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  4872   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  4873   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  4874   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  4875   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  4876   starfun_diff <-- starfun{C,RC,CR}_diff
  4877   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  4878   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  4879   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  4880   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  4881   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  4882   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  4883   starfun_Id <-- starfunC_Id
  4884   starfun_approx <-- starfun{Nat,CR}_approx
  4885   starfun_capprox <-- starfun{C,RC}_capprox
  4886   starfun_abs <-- starfunNat_rabs
  4887   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  4888   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  4889   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  4890   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  4891   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  4892   starfun_add_approx <-- starfunCR_add_approx
  4893   starfun_inverse_inverse <-- starfunC_inverse_inverse
  4894   starfun_divide <-- starfun{C,CR,RC}_divide
  4895   starfun_n <-- starfun{Nat,C}_n
  4896   starfun_n_mult <-- starfun{Nat,C}_n_mult
  4897   starfun_n_add <-- starfun{Nat,C}_n_add
  4898   starfun_n_add_minus <-- starfunNat_n_add_minus
  4899   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  4900   starfun_n_minus <-- starfun{Nat,C}_n_minus
  4901   starfun_n_eq <-- starfun{Nat,C}_n_eq
  4902 
  4903   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  4904   star_n_minus <-- {hypreal,hcomplex}_minus
  4905   star_n_diff <-- {hypreal,hcomplex}_diff
  4906   star_n_mult <-- {hypreal,hcomplex}_mult
  4907   star_n_inverse <-- {hypreal,hcomplex}_inverse
  4908   star_n_le <-- {hypreal,hypnat}_le
  4909   star_n_less <-- {hypreal,hypnat}_less
  4910   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  4911   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  4912   star_n_abs <-- hypreal_hrabs
  4913   star_n_divide <-- hcomplex_divide
  4914 
  4915   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  4916   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  4917   star_of_diff <-- hypreal_of_real_diff
  4918   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  4919   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  4920   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  4921   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  4922   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  4923   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  4924   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  4925   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  4926   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  4927   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  4928   star_of_number_of <-- {hypreal,hcomplex}_number_of
  4929   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  4930   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  4931   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  4932   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  4933   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  4934   star_of_power <-- hypreal_of_real_power
  4935   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  4936 
  4937 * Hyperreal: new method "transfer" that implements the transfer
  4938 principle of nonstandard analysis. With a subgoal that mentions
  4939 nonstandard types like "'a star", the command "apply transfer"
  4940 replaces it with an equivalent one that mentions only standard types.
  4941 To be successful, all free variables must have standard types; non-
  4942 standard variables must have explicit universal quantifiers.
  4943 
  4944 * Hyperreal: A theory of Taylor series.
  4945 
  4946 
  4947 *** HOLCF ***
  4948 
  4949 * Discontinued special version of 'constdefs' (which used to support
  4950 continuous functions) in favor of the general Pure one with full
  4951 type-inference.
  4952 
  4953 * New simplification procedure for solving continuity conditions; it
  4954 is much faster on terms with many nested lambda abstractions (cubic
  4955 instead of exponential time).
  4956 
  4957 * New syntax for domain package: selector names are now optional.
  4958 Parentheses should be omitted unless argument is lazy, for example:
  4959 
  4960   domain 'a stream = cons "'a" (lazy "'a stream")
  4961 
  4962 * New command 'fixrec' for defining recursive functions with pattern
  4963 matching; defining multiple functions with mutual recursion is also
  4964 supported.  Patterns may include the constants cpair, spair, up, sinl,
  4965 sinr, or any data constructor defined by the domain package. The given
  4966 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  4967 syntax and examples.
  4968 
  4969 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  4970 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  4971 but the proof obligation additionally includes an admissibility
  4972 requirement. The packages generate instances of class cpo or pcpo,
  4973 with continuity and strictness theorems for Rep and Abs.
  4974 
  4975 * HOLCF: Many theorems have been renamed according to a more standard naming
  4976 scheme (INCOMPATIBILITY):
  4977 
  4978   foo_inject:  "foo$x = foo$y ==> x = y"
  4979   foo_eq:      "(foo$x = foo$y) = (x = y)"
  4980   foo_less:    "(foo$x << foo$y) = (x << y)"
  4981   foo_strict:  "foo$UU = UU"
  4982   foo_defined: "... ==> foo$x ~= UU"
  4983   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  4984 
  4985 
  4986 *** ZF ***
  4987 
  4988 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  4989 including the First Isomorphism Theorem (on quotienting by the kernel
  4990 of a homomorphism).
  4991 
  4992 * ZF/Simplifier: install second copy of type solver that actually
  4993 makes use of TC rules declared to Isar proof contexts (or locales);
  4994 the old version is still required for ML proof scripts.
  4995 
  4996 
  4997 *** Cube ***
  4998 
  4999 * Converted to Isar theory format; use locales instead of axiomatic
  5000 theories.
  5001 
  5002 
  5003 *** ML ***
  5004 
  5005 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5006 for ||>, ||>>, |>>,
  5007 
  5008 * Pure/library.ML no longer defines its own option datatype, but uses
  5009 that of the SML basis, which has constructors NONE and SOME instead of
  5010 None and Some, as well as exception Option.Option instead of OPTION.
  5011 The functions the, if_none, is_some, is_none have been adapted
  5012 accordingly, while Option.map replaces apsome.
  5013 
  5014 * Pure/library.ML: the exception LIST has been given up in favour of
  5015 the standard exceptions Empty and Subscript, as well as
  5016 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5017 superceded by the standard hd and tl functions etc.
  5018 
  5019 A number of basic list functions are no longer exported to the ML
  5020 toplevel, as they are variants of predefined functions.  The following
  5021 suggests how one can translate existing code:
  5022 
  5023     rev_append xs ys = List.revAppend (xs, ys)
  5024     nth_elem (i, xs) = List.nth (xs, i)
  5025     last_elem xs = List.last xs
  5026     flat xss = List.concat xss
  5027     seq fs = List.app fs
  5028     partition P xs = List.partition P xs
  5029     mapfilter f xs = List.mapPartial f xs
  5030 
  5031 * Pure/library.ML: several combinators for linear functional
  5032 transformations, notably reverse application and composition:
  5033 
  5034   x |> f                f #> g
  5035   (x, y) |-> f          f #-> g
  5036 
  5037 * Pure/library.ML: introduced/changed precedence of infix operators:
  5038 
  5039   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5040   infix 2 ?;
  5041   infix 3 o oo ooo oooo;
  5042   infix 4 ~~ upto downto;
  5043 
  5044 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5045 infix operators.
  5046 
  5047 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5048 fold_map support linear functional transformations and nesting.  For
  5049 example:
  5050 
  5051   fold f [x1, ..., xN] y =
  5052     y |> f x1 |> ... |> f xN
  5053 
  5054   (fold o fold) f [xs1, ..., xsN] y =
  5055     y |> fold f xs1 |> ... |> fold f xsN
  5056 
  5057   fold f [x1, ..., xN] =
  5058     f x1 #> ... #> f xN
  5059 
  5060   (fold o fold) f [xs1, ..., xsN] =
  5061     fold f xs1 #> ... #> fold f xsN
  5062 
  5063 * Pure/library.ML: the following selectors on type 'a option are
  5064 available:
  5065 
  5066   the:               'a option -> 'a  (*partial*)
  5067   these:             'a option -> 'a  where 'a = 'b list
  5068   the_default: 'a -> 'a option -> 'a
  5069   the_list:          'a option -> 'a list
  5070 
  5071 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5072 basic operations for association lists, following natural argument
  5073 order; moreover the explicit equality predicate passed here avoids
  5074 potentially expensive polymorphic runtime equality checks.
  5075 The old functions may be expressed as follows:
  5076 
  5077   assoc = uncurry (AList.lookup (op =))
  5078   assocs = these oo AList.lookup (op =)
  5079   overwrite = uncurry (AList.update (op =)) o swap
  5080 
  5081 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5082 
  5083   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5084   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5085 
  5086 replacing make_keylist and keyfilter (occassionally used)
  5087 Naive rewrites:
  5088 
  5089   make_keylist = AList.make
  5090   keyfilter = AList.find (op =)
  5091 
  5092 * eq_fst and eq_snd now take explicit equality parameter, thus
  5093   avoiding eqtypes. Naive rewrites:
  5094 
  5095     eq_fst = eq_fst (op =)
  5096     eq_snd = eq_snd (op =)
  5097 
  5098 * Removed deprecated apl and apr (rarely used).
  5099   Naive rewrites:
  5100 
  5101     apl (n, op) =>>= curry op n
  5102     apr (op, m) =>>= fn n => op (n, m)
  5103 
  5104 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5105 provides a reasonably efficient light-weight implementation of sets as
  5106 lists.
  5107 
  5108 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5109 few new operations; existing lookup and update are now curried to
  5110 follow natural argument order (for use with fold etc.);
  5111 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5112 
  5113 * Pure/General: output via the Isabelle channels of
  5114 writeln/warning/error etc. is now passed through Output.output, with a
  5115 hook for arbitrary transformations depending on the print_mode
  5116 (cf. Output.add_mode -- the first active mode that provides a output
  5117 function wins).  Already formatted output may be embedded into further
  5118 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5119 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5120 accommodate easy composition of diagnostic messages etc.  Programmers
  5121 rarely need to care about Output.output or Output.raw at all, with
  5122 some notable exceptions: Output.output is required when bypassing the
  5123 standard channels (writeln etc.), or in token translations to produce
  5124 properly formatted results; Output.raw is required when capturing
  5125 already output material that will eventually be presented to the user
  5126 a second time.  For the default print mode, both Output.output and
  5127 Output.raw have no effect.
  5128 
  5129 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5130 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5131 cumulative results are displayed at the end of a batch session.
  5132 
  5133 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5134 replaced by File.platform_path and File.shell_path (with appropriate
  5135 hooks).  This provides a clean interface for unusual systems where the
  5136 internal and external process view of file names are different.
  5137 
  5138 * Pure: more efficient orders for basic syntactic entities: added
  5139 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5140 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5141 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5142 orders now -- potential INCOMPATIBILITY for code that depends on a
  5143 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5144 Library.sort_strings on result).
  5145 
  5146 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5147 fold_types traverse types/terms from left to right, observing natural
  5148 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5149 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5150 
  5151 * Pure: name spaces have been refined, with significant changes of the
  5152 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5153 to extern(_table).  The plain name entry path is superceded by a
  5154 general 'naming' context, which also includes the 'policy' to produce
  5155 a fully qualified name and external accesses of a fully qualified
  5156 name; NameSpace.extend is superceded by context dependent
  5157 Sign.declare_name.  Several theory and proof context operations modify
  5158 the naming context.  Especially note Theory.restore_naming and
  5159 ProofContext.restore_naming to get back to a sane state; note that
  5160 Theory.add_path is no longer sufficient to recover from
  5161 Theory.absolute_path in particular.
  5162 
  5163 * Pure: new flags short_names (default false) and unique_names
  5164 (default true) for controlling output of qualified names.  If
  5165 short_names is set, names are printed unqualified.  If unique_names is
  5166 reset, the name prefix is reduced to the minimum required to achieve
  5167 the original result when interning again, even if there is an overlap
  5168 with earlier declarations.
  5169 
  5170 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5171 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5172 (useful for printing error messages).  INCOMPATIBILITY.
  5173 
  5174 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5175 Theory.theory are now identified, referring to the universal
  5176 Context.theory (see Pure/context.ML).  Actual signature and theory
  5177 content is managed as theory data.  The old code and interfaces were
  5178 spread over many files and structures; the new arrangement introduces
  5179 considerable INCOMPATIBILITY to gain more clarity:
  5180 
  5181   Context -- theory management operations (name, identity, inclusion,
  5182     parents, ancestors, merge, etc.), plus generic theory data;
  5183 
  5184   Sign -- logical signature and syntax operations (declaring consts,
  5185     types, etc.), plus certify/read for common entities;
  5186 
  5187   Theory -- logical theory operations (stating axioms, definitions,
  5188     oracles), plus a copy of logical signature operations (consts,
  5189     types, etc.); also a few basic management operations (Theory.copy,
  5190     Theory.merge, etc.)
  5191 
  5192 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5193 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5194 for convenience -- they merely return the theory.
  5195 
  5196 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5197 
  5198 * Pure: the Isar proof context type is already defined early in Pure
  5199 as Context.proof (note that ProofContext.context and Proof.context are
  5200 aliases, where the latter is the preferred name).  This enables other
  5201 Isabelle components to refer to that type even before Isar is present.
  5202 
  5203 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5204 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5205 any of these kinds.  For example, Sign.intern typeK is now
  5206 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5207 Theory.hide_types.  Also note that former
  5208 Theory.hide_classes/types/consts are now
  5209 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5210 internalize their arguments!  INCOMPATIBILITY.
  5211 
  5212 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5213 datatype thmref (with constructors Name and NameSelection) instead of
  5214 plain string -- INCOMPATIBILITY;
  5215 
  5216 * Pure: cases produced by proof methods specify options, where NONE
  5217 means to remove case bindings -- INCOMPATIBILITY in
  5218 (RAW_)METHOD_CASES.
  5219 
  5220 * Pure: the following operations retrieve axioms or theorems from a
  5221 theory node or theory hierarchy, respectively:
  5222 
  5223   Theory.axioms_of: theory -> (string * term) list
  5224   Theory.all_axioms_of: theory -> (string * term) list
  5225   PureThy.thms_of: theory -> (string * thm) list
  5226   PureThy.all_thms_of: theory -> (string * thm) list
  5227 
  5228 * Pure: print_tac now outputs the goal through the trace channel.
  5229 
  5230 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5231 Reference Toplevel.debug (default false) controls detailed printing
  5232 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5233 controls execution profiling -- set to 1 for time and 2 for space
  5234 (both increase the runtime).
  5235 
  5236 * Isar session: The initial use of ROOT.ML is now always timed,
  5237 i.e. the log will show the actual process times, in contrast to the
  5238 elapsed wall-clock time that the outer shell wrapper produces.
  5239 
  5240 * Simplifier: improved handling of bound variables (nameless
  5241 representation, avoid allocating new strings).  Simprocs that invoke
  5242 the Simplifier recursively should use Simplifier.inherit_bounds to
  5243 avoid local name clashes.  Failure to do so produces warnings
  5244 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5245 for further details.
  5246 
  5247 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5248 bindings for all theorems stored within a given theory; this may help
  5249 in porting non-Isar theories to Isar ones, while keeping ML proof
  5250 scripts for the time being.
  5251 
  5252 * ML operator HTML.with_charset specifies the charset begin used for
  5253 generated HTML files.  For example:
  5254 
  5255   HTML.with_charset "utf-8" use_thy "Hebrew";
  5256   HTML.with_charset "utf-8" use_thy "Chinese";
  5257 
  5258 
  5259 *** System ***
  5260 
  5261 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5262 isabelle, isatool etc.).
  5263 
  5264 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5265 isatool doc, isatool mkdir, display_drafts etc.).
  5266 
  5267 * isatool usedir: option -f allows specification of the ML file to be
  5268 used by Isabelle; default is ROOT.ML.
  5269 
  5270 * New isatool version outputs the version identifier of the Isabelle
  5271 distribution being used.
  5272 
  5273 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5274 (containing Boolean satisfiability problems) into Isabelle/HOL
  5275 theories.
  5276 
  5277 
  5278 
  5279 New in Isabelle2004 (April 2004)
  5280 --------------------------------
  5281 
  5282 *** General ***
  5283 
  5284 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5285   Replaces linorder.ML.
  5286 
  5287 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5288   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5289   (\<a>...\<z>), are now considered normal letters, and can therefore
  5290   be used anywhere where an ASCII letter (a...zA...Z) has until
  5291   now. COMPATIBILITY: This obviously changes the parsing of some
  5292   terms, especially where a symbol has been used as a binder, say
  5293   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5294   as an identifier.  Fix it by inserting a space around former
  5295   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5296   existing theory and ML files.
  5297 
  5298 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5299 
  5300 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5301   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5302   a normal (but invisible) letter. For multiple letter subscripts repeat
  5303   \<^isub> like this: x\<^isub>1\<^isub>2.
  5304 
  5305 * Pure: There are now sub-/superscripts that can span more than one
  5306   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5307   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5308   superscript. The new control characters are not identifier parts.
  5309 
  5310 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5311   content of "..." to the latex file instead of \isacntrl... . The "..."
  5312   may consist of any printable characters excluding the end bracket >.
  5313 
  5314 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5315   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5316   declare constants "final", which prevents their being given a definition
  5317   later.  It is useful for constants whose behaviour is fixed axiomatically
  5318   rather than definitionally, such as the meta-logic connectives.
  5319 
  5320 * Pure: 'instance' now handles general arities with general sorts
  5321   (i.e. intersections of classes),
  5322 
  5323 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5324   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5325   It can be changed to alter the colors/layout of generated pages.
  5326 
  5327 
  5328 *** Isar ***
  5329 
  5330 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5331   cut_tac, subgoal_tac and thin_tac:
  5332   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5333     locales are no longer forced to write Isar proof scripts.
  5334     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5335     emulations.
  5336   - INCOMPATIBILITY: names of variables to be instantiated may no
  5337     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5338     This is consistent with the instantiation attribute "where".
  5339 
  5340 * Attributes "where" and "of":
  5341   - Now take type variables of instantiated theorem into account when reading
  5342     the instantiation string.  This fixes a bug that caused instantiated
  5343     theorems to have too special types in some circumstances.
  5344   - "where" permits explicit instantiations of type variables.
  5345 
  5346 * Calculation commands "moreover" and "also" no longer interfere with
  5347   current facts ("this"), admitting arbitrary combinations with "then"
  5348   and derived forms.
  5349 
  5350 * Locales:
  5351   - Goal statements involving the context element "includes" no longer
  5352     generate theorems with internal delta predicates (those ending on
  5353     "_axioms") in the premise.
  5354     Resolve particular premise with <locale>.intro to obtain old form.
  5355   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5356     specification and "includes" elements in goal statement.
  5357   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5358     [intro?] and [elim?] (respectively) by default.
  5359   - Experimental command for instantiation of locales in proof contexts:
  5360         instantiate <label>[<attrs>]: <loc>
  5361     Instantiates locale <loc> and adds all its theorems to the current context
  5362     taking into account their attributes.  Label and attrs are optional
  5363     modifiers, like in theorem declarations.  If present, names of
  5364     instantiated theorems are qualified with <label>, and the attributes
  5365     <attrs> are applied after any attributes these theorems might have already.
  5366       If the locale has assumptions, a chained fact of the form
  5367     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5368     are derived.  The command does not support old-style locales declared
  5369     with "locale (open)".
  5370       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5371 
  5372 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5373   (Isar) contexts.
  5374 
  5375 
  5376 *** HOL ***
  5377 
  5378 * Proof import: new image HOL4 contains the imported library from
  5379   the HOL4 system with about 2500 theorems. It is imported by
  5380   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5381   can be used like any other Isabelle image.  See
  5382   HOL/Import/HOL/README for more information.
  5383 
  5384 * Simplifier:
  5385   - Much improved handling of linear and partial orders.
  5386     Reasoners for linear and partial orders are set up for type classes
  5387     "linorder" and "order" respectively, and are added to the default simpset
  5388     as solvers.  This means that the simplifier can build transitivity chains
  5389     to solve goals from the assumptions.
  5390   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5391     of blast or auto after simplification become unnecessary because the goal
  5392     is solved by simplification already.
  5393 
  5394 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5395     all proved in axiomatic type classes for semirings, rings and fields.
  5396 
  5397 * Numerics:
  5398   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5399     now formalized using the Ring_and_Field theory mentioned above.
  5400   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5401     than before, because now they are set up once in a generic manner.
  5402   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5403     Look for the general versions in Ring_and_Field (and Power if they concern
  5404     exponentiation).
  5405 
  5406 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5407 
  5408 * Records:
  5409   - Record types are now by default printed with their type abbreviation
  5410     instead of the list of all field types. This can be configured via
  5411     the reference "print_record_type_abbr".
  5412   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5413     (not enabled by default).
  5414   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5415     EX x. x = sel r to True (not enabled by default).
  5416   - Tactic "record_split_simp_tac" to split and simplify records added.
  5417 
  5418 * 'specification' command added, allowing for definition by
  5419   specification.  There is also an 'ax_specification' command that
  5420   introduces the new constants axiomatically.
  5421 
  5422 * arith(_tac) is now able to generate counterexamples for reals as well.
  5423 
  5424 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5425 
  5426 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5427   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5428 
  5429 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5430   matrix theory to linear programming.
  5431 
  5432 * Unions and Intersections:
  5433   The latex output syntax of UN and INT has been changed
  5434   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5435   i.e. the index formulae has become a subscript.
  5436   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5437 
  5438 * Unions and Intersections over Intervals:
  5439   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5440   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5441   like in normal math, and corresponding versions for < and for intersection.
  5442 
  5443 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5444   lexicographic dictonary ordering has been added as "lexord".
  5445 
  5446 * ML: the legacy theory structures Int and List have been removed. They had
  5447   conflicted with ML Basis Library structures having the same names.
  5448 
  5449 * 'refute' command added to search for (finite) countermodels.  Only works
  5450   for a fragment of HOL.  The installation of an external SAT solver is
  5451   highly recommended.  See "HOL/Refute.thy" for details.
  5452 
  5453 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5454   formulae under an assignment of free variables to random values.
  5455   In contrast to 'refute', it can deal with inductive datatypes,
  5456   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5457   for examples.
  5458 
  5459 
  5460 *** HOLCF ***
  5461 
  5462 * Streams now come with concatenation and are part of the HOLCF image
  5463 
  5464 
  5465 
  5466 New in Isabelle2003 (May 2003)
  5467 ------------------------------
  5468 
  5469 *** General ***
  5470 
  5471 * Provers/simplifier:
  5472 
  5473   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5474     Assumptions are now subject to complete mutual simplification,
  5475     not just from left to right. The simplifier now preserves
  5476     the order of assumptions.
  5477 
  5478     Potential INCOMPATIBILITY:
  5479 
  5480     -- simp sometimes diverges where the old version did
  5481        not, e.g. invoking simp on the goal
  5482 
  5483         [| P (f x); y = x; f x = f y |] ==> Q
  5484 
  5485        now gives rise to the infinite reduction sequence
  5486 
  5487         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5488 
  5489        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5490        kind of problem.
  5491 
  5492     -- Tactics combining classical reasoner and simplification (such as auto)
  5493        are also affected by this change, because many of them rely on
  5494        simp. They may sometimes diverge as well or yield a different numbers
  5495        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5496        in case of problems. Sometimes subsequent calls to the classical
  5497        reasoner will fail because a preceeding call to the simplifier too
  5498        eagerly simplified the goal, e.g. deleted redundant premises.
  5499 
  5500   - The simplifier trace now shows the names of the applied rewrite rules
  5501 
  5502   - You can limit the number of recursive invocations of the simplifier
  5503     during conditional rewriting (where the simplifie tries to solve the
  5504     conditions before applying the rewrite rule):
  5505     ML "simp_depth_limit := n"
  5506     where n is an integer. Thus you can force termination where previously
  5507     the simplifier would diverge.
  5508 
  5509   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5510 
  5511   - No longer aborts on failed congruence proof.  Instead, the
  5512     congruence is ignored.
  5513 
  5514 * Pure: New generic framework for extracting programs from constructive
  5515   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5516   as HOL/Extraction for some case studies.
  5517 
  5518 * Pure: The main goal of the proof state is no longer shown by default, only
  5519 the subgoals. This behaviour is controlled by a new flag.
  5520    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5521 (ML: Proof.show_main_goal).
  5522 
  5523 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5524 rules whose conclusion matches subgoal 1:
  5525       PG menu: Isabelle/Isar -> Show me -> matching rules
  5526 The rules are ordered by how closely they match the subgoal.
  5527 In particular, rules that solve a subgoal outright are displayed first
  5528 (or rather last, the way they are printed).
  5529 (ML: ProofGeneral.print_intros())
  5530 
  5531 * Pure: New flag trace_unify_fail causes unification to print
  5532 diagnostic information (PG: in trace buffer) when it fails. This is
  5533 useful for figuring out why single step proofs like rule, erule or
  5534 assumption failed.
  5535 
  5536 * Pure: Locale specifications now produce predicate definitions
  5537 according to the body of text (covering assumptions modulo local
  5538 definitions); predicate "loc_axioms" covers newly introduced text,
  5539 while "loc" is cumulative wrt. all included locale expressions; the
  5540 latter view is presented only on export into the global theory
  5541 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5542 on the old view without predicates;
  5543 
  5544 * Pure: predefined locales "var" and "struct" are useful for sharing
  5545 parameters (as in CASL, for example); just specify something like
  5546 ``var x + var y + struct M'' as import;
  5547 
  5548 * Pure: improved thms_containing: proper indexing of facts instead of
  5549 raw theorems; check validity of results wrt. current name space;
  5550 include local facts of proof configuration (also covers active
  5551 locales), cover fixed variables in index; may use "_" in term
  5552 specification; an optional limit for the number of printed facts may
  5553 be given (the default is 40);
  5554 
  5555 * Pure: disallow duplicate fact bindings within new-style theory files
  5556 (batch-mode only);
  5557 
  5558 * Provers: improved induct method: assumptions introduced by case
  5559 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5560 the goal statement); "foo" still refers to all facts collectively;
  5561 
  5562 * Provers: the function blast.overloaded has been removed: all constants
  5563 are regarded as potentially overloaded, which improves robustness in exchange
  5564 for slight decrease in efficiency;
  5565 
  5566 * Provers/linorder: New generic prover for transitivity reasoning over
  5567 linear orders.  Note: this prover is not efficient!
  5568 
  5569 * Isar: preview of problems to finish 'show' now produce an error
  5570 rather than just a warning (in interactive mode);
  5571 
  5572 
  5573 *** HOL ***
  5574 
  5575 * arith(_tac)
  5576 
  5577  - Produces a counter example if it cannot prove a goal.
  5578    Note that the counter example may be spurious if the goal is not a formula
  5579    of quantifier-free linear arithmetic.
  5580    In ProofGeneral the counter example appears in the trace buffer.
  5581 
  5582  - Knows about div k and mod k where k is a numeral of type nat or int.
  5583 
  5584  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5585    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5586    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5587 
  5588 * simp's arithmetic capabilities have been enhanced a bit: it now
  5589 takes ~= in premises into account (by performing a case split);
  5590 
  5591 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5592 are distributed over a sum of terms;
  5593 
  5594 * New tactic "trans_tac" and method "trans" instantiate
  5595 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5596 "<=", "<" and "=").
  5597 
  5598 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5599 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5600 
  5601 * 'typedef' command has new option "open" to suppress the set
  5602 definition;
  5603 
  5604 * functions Min and Max on finite sets have been introduced (theory
  5605 Finite_Set);
  5606 
  5607 * attribute [symmetric] now works for relations as well; it turns
  5608 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5609 
  5610 * induct over a !!-quantified statement (say !!x1..xn):
  5611   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5612 
  5613 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5614 %x. None. Warning: empty_def now refers to the previously hidden definition
  5615 of the empty set.
  5616 
  5617 * Algebra: formalization of classical algebra.  Intended as base for
  5618 any algebraic development in Isabelle.  Currently covers group theory
  5619 (up to Sylow's theorem) and ring theory (Universal Property of
  5620 Univariate Polynomials).  Contributions welcome;
  5621 
  5622 * GroupTheory: deleted, since its material has been moved to Algebra;
  5623 
  5624 * Complex: new directory of the complex numbers with numeric constants,
  5625 nonstandard complex numbers, and some complex analysis, standard and
  5626 nonstandard (Jacques Fleuriot);
  5627 
  5628 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5629 
  5630 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5631 Fleuriot);
  5632 
  5633 * Real/HahnBanach: updated and adapted to locales;
  5634 
  5635 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5636 Gray and Kramer);
  5637 
  5638 * UNITY: added the Meier-Sanders theory of progress sets;
  5639 
  5640 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5641 as abstract algorithms, instantiated to the JVM;
  5642 
  5643 * Bali: Java source language formalization. Type system, operational
  5644 semantics, axiomatic semantics. Supported language features:
  5645 classes, interfaces, objects,virtual methods, static methods,
  5646 static/instance fields, arrays, access modifiers, definite
  5647 assignment, exceptions.
  5648 
  5649 
  5650 *** ZF ***
  5651 
  5652 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5653 universe, etc.);
  5654 
  5655 * Main ZF: virtually all theories converted to new-style format;
  5656 
  5657 
  5658 *** ML ***
  5659 
  5660 * Pure: Tactic.prove provides sane interface for internal proofs;
  5661 omits the infamous "standard" operation, so this is more appropriate
  5662 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5663 
  5664 * Pure: improved error reporting of simprocs;
  5665 
  5666 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5667 up simprocs;
  5668 
  5669 
  5670 *** Document preparation ***
  5671 
  5672 * uses \par instead of \\ for line breaks in theory text. This may
  5673 shift some page breaks in large documents. To get the old behaviour
  5674 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5675 
  5676 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5677 other packages
  5678 
  5679 * \<euro> now needs package babel/greek instead of marvosym (which
  5680 broke \Rightarrow)
  5681 
  5682 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5683 textcomp package)
  5684 
  5685 
  5686 
  5687 New in Isabelle2002 (March 2002)
  5688 --------------------------------
  5689 
  5690 *** Document preparation ***
  5691 
  5692 * greatly simplified document preparation setup, including more
  5693 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5694 instructive isatool mkdir; users should basically be able to get
  5695 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5696 users may run a separate document processing stage manually like this:
  5697 "isatool usedir -D output HOL Test && isatool document Test/output";
  5698 
  5699 * theory dependency graph may now be incorporated into documents;
  5700 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5701 with \includegraphics of LaTeX;
  5702 
  5703 * proper spacing of consecutive markup elements, especially text
  5704 blocks after section headings;
  5705 
  5706 * support bold style (for single symbols only), input syntax is like
  5707 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5708 
  5709 * \<bullet> is now output as bold \cdot by default, which looks much
  5710 better in printed text;
  5711 
  5712 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5713 note that these symbols are currently unavailable in Proof General /
  5714 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5715 
  5716 * isatool latex no longer depends on changed TEXINPUTS, instead
  5717 isatool document copies the Isabelle style files to the target
  5718 location;
  5719 
  5720 
  5721 *** Isar ***
  5722 
  5723 * Pure/Provers: improved proof by cases and induction;
  5724   - 'case' command admits impromptu naming of parameters (such as
  5725     "case (Suc n)");
  5726   - 'induct' method divinates rule instantiation from the inductive
  5727     claim; no longer requires excessive ?P bindings for proper
  5728     instantiation of cases;
  5729   - 'induct' method properly enumerates all possibilities of set/type
  5730     rules; as a consequence facts may be also passed through *type*
  5731     rules without further ado;
  5732   - 'induct' method now derives symbolic cases from the *rulified*
  5733     rule (before it used to rulify cases stemming from the internal
  5734     atomized version); this means that the context of a non-atomic
  5735     statement becomes is included in the hypothesis, avoiding the
  5736     slightly cumbersome show "PROP ?case" form;
  5737   - 'induct' may now use elim-style induction rules without chaining
  5738     facts, using ``missing'' premises from the goal state; this allows
  5739     rules stemming from inductive sets to be applied in unstructured
  5740     scripts, while still benefitting from proper handling of non-atomic
  5741     statements; NB: major inductive premises need to be put first, all
  5742     the rest of the goal is passed through the induction;
  5743   - 'induct' proper support for mutual induction involving non-atomic
  5744     rule statements (uses the new concept of simultaneous goals, see
  5745     below);
  5746   - append all possible rule selections, but only use the first
  5747     success (no backtracking);
  5748   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5749   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5750   - added 'print_induct_rules' (covered by help item in recent Proof
  5751     General versions);
  5752   - moved induct/cases attributes to Pure, methods to Provers;
  5753   - generic method setup instantiated for FOL and HOL;
  5754 
  5755 * Pure: support multiple simultaneous goal statements, for example
  5756 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5757 meta-level mechanism, this acts as if several individual goals had
  5758 been stated separately; in particular common proof methods need to be
  5759 repeated in order to cover all claims; note that a single elimination
  5760 step is *not* sufficient to establish the two conjunctions, so this
  5761 fails:
  5762 
  5763   assume "A & B" then have A and B ..   (*".." fails*)
  5764 
  5765 better use "obtain" in situations as above; alternative refer to
  5766 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5767 
  5768 * Pure: proper integration with ``locales''; unlike the original
  5769 version by Florian Kammller, Isar locales package high-level proof
  5770 contexts rather than raw logical ones (e.g. we admit to include
  5771 attributes everywhere); operations on locales include merge and
  5772 rename; support for implicit arguments (``structures''); simultaneous
  5773 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5774 some examples;
  5775 
  5776 * Pure: the following commands have been ``localized'', supporting a
  5777 target locale specification "(in name)": 'lemma', 'theorem',
  5778 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5779 stored both within the locale and at the theory level (exported and
  5780 qualified by the locale name);
  5781 
  5782 * Pure: theory goals may now be specified in ``long'' form, with
  5783 ad-hoc contexts consisting of arbitrary locale elements. for example
  5784 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5785 definitions may be given, too); the result is a meta-level rule with
  5786 the context elements being discharged in the obvious way;
  5787 
  5788 * Pure: new proof command 'using' allows to augment currently used
  5789 facts after a goal statement ('using' is syntactically analogous to
  5790 'apply', but acts on the goal's facts only); this allows chained facts
  5791 to be separated into parts given before and after a claim, as in
  5792 ``from a and b have C using d and e <proof>'';
  5793 
  5794 * Pure: renamed "antecedent" case to "rule_context";
  5795 
  5796 * Pure: new 'judgment' command records explicit information about the
  5797 object-logic embedding (used by several tools internally); no longer
  5798 use hard-wired "Trueprop";
  5799 
  5800 * Pure: added 'corollary' command;
  5801 
  5802 * Pure: fixed 'token_translation' command;
  5803 
  5804 * Pure: removed obsolete 'exported' attribute;
  5805 
  5806 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  5807 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  5808 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  5809 
  5810 * Pure: method 'atomize' presents local goal premises as object-level
  5811 statements (atomic meta-level propositions); setup controlled via
  5812 rewrite rules declarations of 'atomize' attribute; example
  5813 application: 'induct' method with proper rule statements in improper
  5814 proof *scripts*;
  5815 
  5816 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  5817 now consider the syntactic context of assumptions, giving a better
  5818 chance to get type-inference of the arguments right (this is
  5819 especially important for locales);
  5820 
  5821 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  5822 mode;
  5823 
  5824 * Pure/obtain: the formal conclusion "thesis", being marked as
  5825 ``internal'', may no longer be reference directly in the text;
  5826 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  5827 situations;
  5828 
  5829 * Pure: generic 'sym' attribute which declares a rule both as pure
  5830 'elim?' and for the 'symmetric' operation;
  5831 
  5832 * Pure: marginal comments ``--'' may now occur just anywhere in the
  5833 text; the fixed correlation with particular command syntax has been
  5834 discontinued;
  5835 
  5836 * Pure: new method 'rules' is particularly well-suited for proof
  5837 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  5838 but often produces more compact proof terms with less detours;
  5839 
  5840 * Pure/Provers/classical: simplified integration with pure rule
  5841 attributes and methods; the classical "intro?/elim?/dest?"
  5842 declarations coincide with the pure ones; the "rule" method no longer
  5843 includes classically swapped intros; "intro" and "elim" methods no
  5844 longer pick rules from the context; also got rid of ML declarations
  5845 AddXIs/AddXEs/AddXDs; all of this has some potential for
  5846 INCOMPATIBILITY;
  5847 
  5848 * Provers/classical: attribute 'swapped' produces classical inversions
  5849 of introduction rules;
  5850 
  5851 * Provers/simplifier: 'simplified' attribute may refer to explicit
  5852 rules instead of full simplifier context; 'iff' attribute handles
  5853 conditional rules;
  5854 
  5855 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  5856 
  5857 * HOL: 'recdef' now fails on unfinished automated proofs, use
  5858 "(permissive)" option to recover old behavior;
  5859 
  5860 * HOL: 'inductive' no longer features separate (collective) attributes
  5861 for 'intros' (was found too confusing);
  5862 
  5863 * HOL: properly declared induction rules less_induct and
  5864 wf_induct_rule;
  5865 
  5866 
  5867 *** HOL ***
  5868 
  5869 * HOL: moved over to sane numeral syntax; the new policy is as
  5870 follows:
  5871 
  5872   - 0 and 1 are polymorphic constants, which are defined on any
  5873   numeric type (nat, int, real etc.);
  5874 
  5875   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  5876   binary representation internally;
  5877 
  5878   - type nat has special constructor Suc, and generally prefers Suc 0
  5879   over 1::nat and Suc (Suc 0) over 2::nat;
  5880 
  5881 This change may cause significant problems of INCOMPATIBILITY; here
  5882 are some hints on converting existing sources:
  5883 
  5884   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  5885   entities, so expressions involving "-" (unary or binary minus) need
  5886   to be spaced properly;
  5887 
  5888   - existing occurrences of "1" may need to be constraint "1::nat" or
  5889   even replaced by Suc 0; similar for old "2";
  5890 
  5891   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  5892 
  5893   - remove all special provisions on numerals in proofs;
  5894 
  5895 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  5896 representation (depends on bin_arith_simps in the default context);
  5897 
  5898 * HOL: symbolic syntax for x^2 (numeral 2);
  5899 
  5900 * HOL: the class of all HOL types is now called "type" rather than
  5901 "term"; INCOMPATIBILITY, need to adapt references to this type class
  5902 in axclass/classes, instance/arities, and (usually rare) occurrences
  5903 in typings (of consts etc.); internally the class is called
  5904 "HOL.type", ML programs should refer to HOLogic.typeS;
  5905 
  5906 * HOL/record package improvements:
  5907   - new derived operations "fields" to build a partial record section,
  5908     "extend" to promote a fixed record to a record scheme, and
  5909     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  5910     declared as simp by default;
  5911   - shared operations ("more", "fields", etc.) now need to be always
  5912     qualified) --- potential INCOMPATIBILITY;
  5913   - removed "make_scheme" operations (use "make" with "extend") --
  5914     INCOMPATIBILITY;
  5915   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  5916   - provides cases/induct rules for use with corresponding Isar
  5917     methods (for concrete records, record schemes, concrete more
  5918     parts, and schematic more parts -- in that order);
  5919   - internal definitions directly based on a light-weight abstract
  5920     theory of product types over typedef rather than datatype;
  5921 
  5922 * HOL: generic code generator for generating executable ML code from
  5923 specifications; specific support for HOL constructs such as inductive
  5924 datatypes and sets, as well as recursive functions; can be invoked
  5925 via 'generate_code' theory section;
  5926 
  5927 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  5928 
  5929 * HOL: consolidated and renamed several theories.  In particular:
  5930         Ord.thy has been absorbed into HOL.thy
  5931         String.thy has been absorbed into List.thy
  5932 
  5933 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  5934 (beware of argument permutation!);
  5935 
  5936 * HOL: linorder_less_split superseded by linorder_cases;
  5937 
  5938 * HOL/List: "nodups" renamed to "distinct";
  5939 
  5940 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  5941 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  5942   - Ex_def has changed, now need to use some_eq_ex
  5943 
  5944 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  5945 in this (rare) case use:
  5946 
  5947   delSWrapper "split_all_tac"
  5948   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  5949 
  5950 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  5951 MAY FAIL;
  5952 
  5953 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  5954 Isabelle's type classes, ^ on functions and relations has too general
  5955 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  5956 necessary to attach explicit type constraints;
  5957 
  5958 * HOL/Relation: the prefix name of the infix "O" has been changed from
  5959 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  5960 renamed accordingly (eg "compI" -> "rel_compI").
  5961 
  5962 * HOL: syntax translations now work properly with numerals and records
  5963 expressions;
  5964 
  5965 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  5966 of "lam" -- INCOMPATIBILITY;
  5967 
  5968 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  5969 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  5970 renamed "Product_Type.unit";
  5971 
  5972 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  5973 
  5974 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  5975 the "cases" method);
  5976 
  5977 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  5978 Florian Kammller);
  5979 
  5980 * HOL/IMP: updated and converted to new-style theory format; several
  5981 parts turned into readable document, with proper Isar proof texts and
  5982 some explanations (by Gerwin Klein);
  5983 
  5984 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  5985 
  5986 * HOL-Hyperreal is now a logic image;
  5987 
  5988 
  5989 *** HOLCF ***
  5990 
  5991 * Isar: consts/constdefs supports mixfix syntax for continuous
  5992 operations;
  5993 
  5994 * Isar: domain package adapted to new-style theory format, e.g. see
  5995 HOLCF/ex/Dnat.thy;
  5996 
  5997 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  5998 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  5999 lift.induct_tac, always use UU instead of Undef;
  6000 
  6001 * HOLCF/IMP: updated and converted to new-style theory;
  6002 
  6003 
  6004 *** ZF ***
  6005 
  6006 * Isar: proper integration of logic-specific tools and packages,
  6007 including theory commands '(co)inductive', '(co)datatype',
  6008 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6009 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6010 
  6011 * theory Main no longer includes AC; for the Axiom of Choice, base
  6012 your theory on Main_ZFC;
  6013 
  6014 * the integer library now covers quotients and remainders, with many
  6015 laws relating division to addition, multiplication, etc.;
  6016 
  6017 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6018 typeless version of the formalism;
  6019 
  6020 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6021 format;
  6022 
  6023 * ZF/Induct: new directory for examples of inductive definitions,
  6024 including theory Multiset for multiset orderings; converted to
  6025 new-style theory format;
  6026 
  6027 * ZF: many new theorems about lists, ordinals, etc.;
  6028 
  6029 
  6030 *** General ***
  6031 
  6032 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6033 variable proof controls level of detail: 0 = no proofs (only oracle
  6034 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6035 also ref manual for further ML interfaces;
  6036 
  6037 * Pure/axclass: removed obsolete ML interface
  6038 goal_subclass/goal_arity;
  6039 
  6040 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6041 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6042 separate tokens, so expressions involving minus need to be spaced
  6043 properly;
  6044 
  6045 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6046 rather than "infixl" or "infixr";
  6047 
  6048 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6049 sort constraint specifications in type inference; e.g. "x::_::foo"
  6050 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6051 type variable);
  6052 
  6053 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6054 control output of nested => (types); the default behavior is
  6055 "type_brackets";
  6056 
  6057 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6058 tokens into AST constants;
  6059 
  6060 * Pure/syntax: prefer later declarations of translations and print
  6061 translation functions; potential INCOMPATIBILITY: need to reverse
  6062 multiple declarations for same syntax element constant;
  6063 
  6064 * Pure/show_hyps reset by default (in accordance to existing Isar
  6065 practice);
  6066 
  6067 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6068 addSafter;
  6069 
  6070 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6071 as well;
  6072 
  6073 * system: tested support for MacOS X; should be able to get Isabelle +
  6074 Proof General to work in a plain Terminal after installing Poly/ML
  6075 (e.g. from the Isabelle distribution area) and GNU bash alone
  6076 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6077 support requires further installations, e.g. from
  6078 http://fink.sourceforge.net/);
  6079 
  6080 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6081 
  6082 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6083 of 40 MB), cf. ML_OPTIONS;
  6084 
  6085 * system: Proof General keywords specification is now part of the
  6086 Isabelle distribution (see etc/isar-keywords.el);
  6087 
  6088 * system: support for persistent Proof General sessions (refrain from
  6089 outdating all loaded theories on startup); user may create writable
  6090 logic images like this: ``isabelle -q HOL Test'';
  6091 
  6092 * system: smart selection of Isabelle process versus Isabelle
  6093 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6094 run both "isabelle" and "Isabelle" even if file names are badly
  6095 damaged (executable inspects the case of the first letter of its own
  6096 name); added separate "isabelle-process" and "isabelle-interface";
  6097 
  6098 * system: refrain from any attempt at filtering input streams; no
  6099 longer support ``8bit'' encoding of old isabelle font, instead proper
  6100 iso-latin characters may now be used; the related isatools
  6101 "symbolinput" and "nonascii" have disappeared as well;
  6102 
  6103 * system: removed old "xterm" interface (the print modes "xterm" and
  6104 "xterm_color" are still available for direct use in a suitable
  6105 terminal);
  6106 
  6107 
  6108 
  6109 New in Isabelle99-2 (February 2001)
  6110 -----------------------------------
  6111 
  6112 *** Overview of INCOMPATIBILITIES ***
  6113 
  6114 * HOL: please note that theories in the Library and elsewhere often use the
  6115 new-style (Isar) format; to refer to their theorems in an ML script you must
  6116 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6117 
  6118 * HOL: inductive package no longer splits induction rule aggressively,
  6119 but only as far as specified by the introductions given; the old
  6120 format may be recovered via ML function complete_split_rule or attribute
  6121 'split_rule (complete)';
  6122 
  6123 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6124 gfp_Tarski to gfp_unfold;
  6125 
  6126 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6127 
  6128 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6129 relation); infix "^^" has been renamed "``"; infix "``" has been
  6130 renamed "`"; "univalent" has been renamed "single_valued";
  6131 
  6132 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6133 operation;
  6134 
  6135 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6136 
  6137 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6138 
  6139 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6140 consequence, it is no longer monotonic wrt. the local goal context
  6141 (which is now passed through the inductive cases);
  6142 
  6143 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6144 \<gg> to \<ggreater>;
  6145 
  6146 
  6147 *** Document preparation ***
  6148 
  6149 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6150 available: are "it" for near math-mode best-style output, "sl" for
  6151 slanted text style, and "tt" for plain type-writer; if no
  6152 \isabellestyle command is given, output is according to slanted
  6153 type-writer);
  6154 
  6155 * support sub/super scripts (for single symbols only), input syntax is
  6156 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6157 
  6158 * some more standard symbols; see Appendix A of the system manual for
  6159 the complete list of symbols defined in isabellesym.sty;
  6160 
  6161 * improved isabelle style files; more abstract symbol implementation
  6162 (should now use \isamath{...} and \isatext{...} in custom symbol
  6163 definitions);
  6164 
  6165 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6166 state; Note that presentation of goal states does not conform to
  6167 actual human-readable proof documents.  Please do not include goal
  6168 states into document output unless you really know what you are doing!
  6169 
  6170 * proper indentation of antiquoted output with proportional LaTeX
  6171 fonts;
  6172 
  6173 * no_document ML operator temporarily disables LaTeX document
  6174 generation;
  6175 
  6176 * isatool unsymbolize tunes sources for plain ASCII communication;
  6177 
  6178 
  6179 *** Isar ***
  6180 
  6181 * Pure: Isar now suffers initial goal statements to contain unbound
  6182 schematic variables (this does not conform to actual readable proof
  6183 documents, due to unpredictable outcome and non-compositional proof
  6184 checking); users who know what they are doing may use schematic goals
  6185 for Prolog-style synthesis of proven results;
  6186 
  6187 * Pure: assumption method (an implicit finishing) now handles actual
  6188 rules as well;
  6189 
  6190 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6191 initial goal, declare "that" only as Pure intro (only for single
  6192 steps); the "that" rule assumption may now be involved in implicit
  6193 finishing, thus ".." becomes a feasible for trivial obtains;
  6194 
  6195 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6196 instance proofs may be performed by "..";
  6197 
  6198 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6199 statements as well;
  6200 
  6201 * Pure: more robust selection of calculational rules;
  6202 
  6203 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6204 rule (as well as the assumption rule);
  6205 
  6206 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6207 lemmas, using the graph browser tool;
  6208 
  6209 * Pure: predict failure of "show" in interactive mode;
  6210 
  6211 * Pure: 'thms_containing' now takes actual terms as arguments;
  6212 
  6213 * HOL: improved method 'induct' --- now handles non-atomic goals
  6214 (potential INCOMPATIBILITY); tuned error handling;
  6215 
  6216 * HOL: cases and induct rules now provide explicit hints about the
  6217 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6218 any remaining facts are inserted into the goal verbatim;
  6219 
  6220 * HOL: local contexts (aka cases) may now contain term bindings as
  6221 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6222 the result to be shown in each case;
  6223 
  6224 * HOL: added 'recdef_tc' command;
  6225 
  6226 * isatool convert assists in eliminating legacy ML scripts;
  6227 
  6228 
  6229 *** HOL ***
  6230 
  6231 * HOL/Library: a collection of generic theories to be used together
  6232 with main HOL; the theory loader path already includes this directory
  6233 by default; the following existing theories have been moved here:
  6234 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While