NEWS
author bulwahn
Wed, 30 Mar 2011 09:44:17 +0200
changeset 43031 43cba90b080f
parent 43020 7e6f4ca198bb
child 43051 a6c141925a8a
permissions -rw-r--r--
NEWS
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) is has been
    26 discontinued.  INCOMPATIBILITY.
    27 
    28 * Various optional external tools are referenced more robustly and
    29 uniformly by explicit Isabelle settings as follows:
    30 
    31   ISABELLE_CSDP   (formerly CSDP_EXE)
    32   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    33   ISABELLE_OCAML  (formerly EXEC_OCAML)
    34   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    35   ISABELLE_YAP    (formerly EXEC_YAP)
    36 
    37 Note that automated detection from the file-system or search path has
    38 been discontinued.  INCOMPATIBILITY.
    39 
    40 
    41 *** HOL ***
    42 
    43 * Nitpick:
    44   - Added "need" and "total_consts" options.
    45   - Reintroduced "show_skolems" option by popular demand.
    46   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    47     INCOMPATIBILITY.
    48 
    49 * Sledgehammer:
    50   - sledgehammer available_provers ~> sledgehammer supported_provers
    51     INCOMPATIBILITY.
    52 
    53 * "try":
    54   - Added "simp:", "intro:", and "elim:" options.
    55 
    56 * Quickcheck:
    57   - Added "eval" option to evaluate terms for the found counterexample
    58     (currently only supported by the default (exhaustive) tester)
    59   - Added post-processing of terms to obtain readable counterexamples
    60     (currently only supported by the default (exhaustive) tester)
    61 
    62 * Function package: discontinued option "tailrec".
    63 INCOMPATIBILITY. Use partial_function instead.
    64 
    65 * HOL-Probability:
    66   - Caratheodory's extension lemma is now proved for ring_of_sets.
    67   - Infinite products of probability measures are now available.
    68   - Use extended reals instead of positive extended reals.
    69     INCOMPATIBILITY.
    70 
    71 *** Document preparation ***
    72 
    73 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    74 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    75 
    76 
    77 *** ML ***
    78 
    79 * Structure Timing provides various operations for timing; supersedes
    80 former start_timing/end_timing etc.
    81 
    82 * Path.print is the official way to show file-system paths to users
    83 (including quotes etc.).
    84 
    85 * Inner syntax: identifiers in parse trees of generic categories
    86 "logic", "aprop", "idt" etc. carry position information (disguised as
    87 type constraints).  Occasional INCOMPATIBILITY with non-compliant
    88 translations that choke on unexpected type constraints.  Positions can
    89 be stripped in ML translations via Syntax.strip_positions /
    90 Syntax.strip_positions_ast, or via the syntax constant
    91 "_strip_positions" within parse trees.  As last resort, positions can
    92 be disabled via the configuration option Syntax.positions, which is
    93 called "syntax_positions" in Isar attribute syntax.
    94 
    95 
    96 
    97 New in Isabelle2011 (January 2011)
    98 ----------------------------------
    99 
   100 *** General ***
   101 
   102 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   103 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   104 useful tooltips and hyperlinks produced from its static analysis.  The
   105 bundled component provides an executable Isabelle tool that can be run
   106 like this:
   107 
   108   Isabelle2011/bin/isabelle jedit
   109 
   110 * Significantly improved Isabelle/Isar implementation manual.
   111 
   112 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   113 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   114 while the default heap location within that directory lacks that extra
   115 suffix.  This isolates multiple Isabelle installations from each
   116 other, avoiding problems with old settings in new versions.
   117 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   118 
   119 * Source files are always encoded as UTF-8, instead of old-fashioned
   120 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   121 the following package declarations:
   122 
   123   \usepackage[utf8]{inputenc}
   124   \usepackage{textcomp}
   125 
   126 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   127 a Unicode character is treated as a single symbol, not a sequence of
   128 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   129 contain symbols without further backslash escapes, Unicode can now be
   130 used here as well.  Recall that Symbol.explode in ML provides a
   131 consistent view on symbols, while raw explode (or String.explode)
   132 merely give a byte-oriented representation.
   133 
   134 * Theory loader: source files are primarily located via the master
   135 directory of each theory node (where the .thy file itself resides).
   136 The global load path is still partially available as legacy feature.
   137 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   138 explicit paths, relatively to the theory.
   139 
   140 * Special treatment of ML file names has been discontinued.
   141 Historically, optional extensions .ML or .sml were added on demand --
   142 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   143 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   144 
   145 * Various options that affect pretty printing etc. are now properly
   146 handled within the context via configuration options, instead of
   147 unsynchronized references or print modes.  There are both ML Config.T
   148 entities and Isar declaration attributes to access these.
   149 
   150   ML (Config.T)                 Isar (attribute)
   151 
   152   eta_contract                  eta_contract
   153   show_brackets                 show_brackets
   154   show_sorts                    show_sorts
   155   show_types                    show_types
   156   show_question_marks           show_question_marks
   157   show_consts                   show_consts
   158   show_abbrevs                  show_abbrevs
   159 
   160   Syntax.ast_trace              syntax_ast_trace
   161   Syntax.ast_stat               syntax_ast_stat
   162   Syntax.ambiguity_level        syntax_ambiguity_level
   163 
   164   Goal_Display.goals_limit      goals_limit
   165   Goal_Display.show_main_goal   show_main_goal
   166 
   167   Method.rule_trace             rule_trace
   168 
   169   Thy_Output.display            thy_output_display
   170   Thy_Output.quotes             thy_output_quotes
   171   Thy_Output.indent             thy_output_indent
   172   Thy_Output.source             thy_output_source
   173   Thy_Output.break              thy_output_break
   174 
   175 Note that corresponding "..._default" references in ML may only be
   176 changed globally at the ROOT session setup, but *not* within a theory.
   177 The option "show_abbrevs" supersedes the former print mode
   178 "no_abbrevs" with inverted meaning.
   179 
   180 * More systematic naming of some configuration options.
   181 INCOMPATIBILITY.
   182 
   183   trace_simp  ~>  simp_trace
   184   debug_simp  ~>  simp_debug
   185 
   186 * Support for real valued configuration options, using simplistic
   187 floating-point notation that coincides with the inner syntax for
   188 float_token.
   189 
   190 * Support for real valued preferences (with approximative PGIP type):
   191 front-ends need to accept "pgint" values in float notation.
   192 INCOMPATIBILITY.
   193 
   194 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   195 DejaVu Sans.
   196 
   197 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   198 
   199 
   200 *** Pure ***
   201 
   202 * Command 'type_synonym' (with single argument) replaces somewhat
   203 outdated 'types', which is still available as legacy feature for some
   204 time.
   205 
   206 * Command 'nonterminal' (with 'and' separated list of arguments)
   207 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   208 
   209 * Command 'notepad' replaces former 'example_proof' for
   210 experimentation in Isar without any result.  INCOMPATIBILITY.
   211 
   212 * Locale interpretation commands 'interpret' and 'sublocale' accept
   213 lists of equations to map definitions in a locale to appropriate
   214 entities in the context of the interpretation.  The 'interpretation'
   215 command already provided this functionality.
   216 
   217 * Diagnostic command 'print_dependencies' prints the locale instances
   218 that would be activated if the specified expression was interpreted in
   219 the current context.  Variant "print_dependencies!" assumes a context
   220 without interpretations.
   221 
   222 * Diagnostic command 'print_interps' prints interpretations in proofs
   223 in addition to interpretations in theories.
   224 
   225 * Discontinued obsolete 'global' and 'local' commands to manipulate
   226 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   227 Sign.root_path and Sign.local_path may be applied directly where this
   228 feature is still required for historical reasons.
   229 
   230 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   231 'definition' instead.
   232 
   233 * The "prems" fact, which refers to the accidental collection of
   234 foundational premises in the context, is now explicitly marked as
   235 legacy feature and will be discontinued soon.  Consider using "assms"
   236 of the head statement or reference facts by explicit names.
   237 
   238 * Document antiquotations @{class} and @{type} print classes and type
   239 constructors.
   240 
   241 * Document antiquotation @{file} checks file/directory entries within
   242 the local file system.
   243 
   244 
   245 *** HOL ***
   246 
   247 * Coercive subtyping: functions can be declared as coercions and type
   248 inference will add them as necessary upon input of a term.  Theory
   249 Complex_Main declares real :: nat => real and real :: int => real as
   250 coercions. A coercion function f is declared like this:
   251 
   252   declare [[coercion f]]
   253 
   254 To lift coercions through type constructors (e.g. from nat => real to
   255 nat list => real list), map functions can be declared, e.g.
   256 
   257   declare [[coercion_map map]]
   258 
   259 Currently coercion inference is activated only in theories including
   260 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   261 the configuration option "coercion_enabled", e.g. it can be enabled in
   262 other theories like this:
   263 
   264   declare [[coercion_enabled]]
   265 
   266 * Command 'partial_function' provides basic support for recursive
   267 function definitions over complete partial orders.  Concrete instances
   268 are provided for i) the option type, ii) tail recursion on arbitrary
   269 types, and iii) the heap monad of Imperative_HOL.  See
   270 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   271 for examples.
   272 
   273 * Function package: f.psimps rules are no longer implicitly declared
   274 as [simp].  INCOMPATIBILITY.
   275 
   276 * Datatype package: theorems generated for executable equality (class
   277 "eq") carry proper names and are treated as default code equations.
   278 
   279 * Inductive package: now offers command 'inductive_simps' to
   280 automatically derive instantiated and simplified equations for
   281 inductive predicates, similar to 'inductive_cases'.
   282 
   283 * Command 'enriched_type' allows to register properties of the
   284 functorial structure of types.
   285 
   286 * Improved infrastructure for term evaluation using code generator
   287 techniques, in particular static evaluation conversions.
   288 
   289 * Code generator: Scala (2.8 or higher) has been added to the target
   290 languages.
   291 
   292 * Code generator: globbing constant expressions "*" and "Theory.*"
   293 have been replaced by the more idiomatic "_" and "Theory._".
   294 INCOMPATIBILITY.
   295 
   296 * Code generator: export_code without explicit file declaration prints
   297 to standard output.  INCOMPATIBILITY.
   298 
   299 * Code generator: do not print function definitions for case
   300 combinators any longer.
   301 
   302 * Code generator: simplification with rules determined with
   303 src/Tools/Code/code_simp.ML and method "code_simp".
   304 
   305 * Code generator for records: more idiomatic representation of record
   306 types.  Warning: records are not covered by ancient SML code
   307 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   308 rep_datatype declaration helps to succeed then:
   309 
   310   record 'a foo = ...
   311   ...
   312   rep_datatype foo_ext ...
   313 
   314 * Records: logical foundation type for records does not carry a
   315 '_type' suffix any longer (obsolete due to authentic syntax).
   316 INCOMPATIBILITY.
   317 
   318 * Quickcheck now by default uses exhaustive testing instead of random
   319 testing.  Random testing can be invoked by "quickcheck [random]",
   320 exhaustive testing by "quickcheck [exhaustive]".
   321 
   322 * Quickcheck instantiates polymorphic types with small finite
   323 datatypes by default. This enables a simple execution mechanism to
   324 handle quantifiers and function equality over the finite datatypes.
   325 
   326 * Quickcheck random generator has been renamed from "code" to
   327 "random".  INCOMPATIBILITY.
   328 
   329 * Quickcheck now has a configurable time limit which is set to 30
   330 seconds by default. This can be changed by adding [timeout = n] to the
   331 quickcheck command. The time limit for Auto Quickcheck is still set
   332 independently.
   333 
   334 * Quickcheck in locales considers interpretations of that locale for
   335 counter example search.
   336 
   337 * Sledgehammer:
   338   - Added "smt" and "remote_smt" provers based on the "smt" proof
   339     method. See the Sledgehammer manual for details ("isabelle doc
   340     sledgehammer").
   341   - Renamed commands:
   342     sledgehammer atp_info ~> sledgehammer running_provers
   343     sledgehammer atp_kill ~> sledgehammer kill_provers
   344     sledgehammer available_atps ~> sledgehammer available_provers
   345     INCOMPATIBILITY.
   346   - Renamed options:
   347     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   348     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   349     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   350     (and "ms" and "min" are no longer supported)
   351     INCOMPATIBILITY.
   352 
   353 * Nitpick:
   354   - Renamed options:
   355     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   356     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   357     INCOMPATIBILITY.
   358   - Added support for partial quotient types.
   359   - Added local versions of the "Nitpick.register_xxx" functions.
   360   - Added "whack" option.
   361   - Allow registration of quotient types as codatatypes.
   362   - Improved "merge_type_vars" option to merge more types.
   363   - Removed unsound "fast_descrs" option.
   364   - Added custom symmetry breaking for datatypes, making it possible to reach
   365     higher cardinalities.
   366   - Prevent the expansion of too large definitions.
   367 
   368 * Proof methods "metis" and "meson" now have configuration options
   369 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   370 to diagnose these tools. E.g.
   371 
   372     using [[metis_trace = true]]
   373 
   374 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   375 manually as command 'solve_direct'.
   376 
   377 * The default SMT solver Z3 must be enabled explicitly (due to
   378 licensing issues) by setting the environment variable
   379 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   380 commercial applications, the SMT solver CVC3 is provided as fall-back;
   381 changing the SMT solver is done via the configuration option
   382 "smt_solver".
   383 
   384 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   385 i.e. "remote_cvc3" and "remote_z3".
   386 
   387 * Added basic SMT support for datatypes, records, and typedefs using
   388 the oracle mode (no proofs).  Direct support of pairs has been dropped
   389 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   390 support for a similar behavior).  Minor INCOMPATIBILITY.
   391 
   392 * Changed SMT configuration options:
   393   - Renamed:
   394     z3_proofs ~> smt_oracle (with inverted meaning)
   395     z3_trace_assms ~> smt_trace_used_facts
   396     INCOMPATIBILITY.
   397   - Added:
   398     smt_verbose
   399     smt_random_seed
   400     smt_datatypes
   401     smt_infer_triggers
   402     smt_monomorph_limit
   403     cvc3_options
   404     remote_cvc3_options
   405     remote_z3_options
   406     yices_options
   407 
   408 * Boogie output files (.b2i files) need to be declared in the theory
   409 header.
   410 
   411 * Simplification procedure "list_to_set_comprehension" rewrites list
   412 comprehensions applied to List.set to set comprehensions.  Occasional
   413 INCOMPATIBILITY, may be deactivated like this:
   414 
   415   declare [[simproc del: list_to_set_comprehension]]
   416 
   417 * Removed old version of primrec package.  INCOMPATIBILITY.
   418 
   419 * Removed simplifier congruence rule of "prod_case", as has for long
   420 been the case with "split".  INCOMPATIBILITY.
   421 
   422 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   423 
   424 * Removed [split_format ... and ... and ...] version of
   425 [split_format].  Potential INCOMPATIBILITY.
   426 
   427 * Predicate "sorted" now defined inductively, with nice induction
   428 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   429 
   430 * Constant "contents" renamed to "the_elem", to free the generic name
   431 contents for other uses.  INCOMPATIBILITY.
   432 
   433 * Renamed class eq and constant eq (for code generation) to class
   434 equal and constant equal, plus renaming of related facts and various
   435 tuning.  INCOMPATIBILITY.
   436 
   437 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   438 
   439 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   440 INCOMPATIBILITY.
   441 
   442 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   443 avoid confusion with finite sets.  INCOMPATIBILITY.
   444 
   445 * Abandoned locales equiv, congruent and congruent2 for equivalence
   446 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   447 for congruent(2)).
   448 
   449 * Some previously unqualified names have been qualified:
   450 
   451   types
   452     bool ~> HOL.bool
   453     nat ~> Nat.nat
   454 
   455   constants
   456     Trueprop ~> HOL.Trueprop
   457     True ~> HOL.True
   458     False ~> HOL.False
   459     op & ~> HOL.conj
   460     op | ~> HOL.disj
   461     op --> ~> HOL.implies
   462     op = ~> HOL.eq
   463     Not ~> HOL.Not
   464     The ~> HOL.The
   465     All ~> HOL.All
   466     Ex ~> HOL.Ex
   467     Ex1 ~> HOL.Ex1
   468     Let ~> HOL.Let
   469     If ~> HOL.If
   470     Ball ~> Set.Ball
   471     Bex ~> Set.Bex
   472     Suc ~> Nat.Suc
   473     Pair ~> Product_Type.Pair
   474     fst ~> Product_Type.fst
   475     snd ~> Product_Type.snd
   476     curry ~> Product_Type.curry
   477     op : ~> Set.member
   478     Collect ~> Set.Collect
   479 
   480 INCOMPATIBILITY.
   481 
   482 * More canonical naming convention for some fundamental definitions:
   483 
   484     bot_bool_eq ~> bot_bool_def
   485     top_bool_eq ~> top_bool_def
   486     inf_bool_eq ~> inf_bool_def
   487     sup_bool_eq ~> sup_bool_def
   488     bot_fun_eq  ~> bot_fun_def
   489     top_fun_eq  ~> top_fun_def
   490     inf_fun_eq  ~> inf_fun_def
   491     sup_fun_eq  ~> sup_fun_def
   492 
   493 INCOMPATIBILITY.
   494 
   495 * More stylized fact names:
   496 
   497   expand_fun_eq ~> fun_eq_iff
   498   expand_set_eq ~> set_eq_iff
   499   set_ext       ~> set_eqI
   500   nat_number    ~> eval_nat_numeral
   501 
   502 INCOMPATIBILITY.
   503 
   504 * Refactoring of code-generation specific operations in theory List:
   505 
   506   constants
   507     null ~> List.null
   508 
   509   facts
   510     mem_iff ~> member_def
   511     null_empty ~> null_def
   512 
   513 INCOMPATIBILITY.  Note that these were not supposed to be used
   514 regularly unless for striking reasons; their main purpose was code
   515 generation.
   516 
   517 Various operations from the Haskell prelude are used for generating
   518 Haskell code.
   519 
   520 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   521 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   522 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   523 
   524 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   525 "*" and "+" respectively.  INCOMPATIBILITY.
   526 
   527 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   528 "Sum_Type.Plus" instead.
   529 
   530 * Constant "split" has been merged with constant "prod_case"; names of
   531 ML functions, facts etc. involving split have been retained so far,
   532 though.  INCOMPATIBILITY.
   533 
   534 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   535 instead.  INCOMPATIBILITY.
   536 
   537 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   538 INCOMPATIBILITY.
   539 
   540 * Former theory Library/Enum is now part of the HOL-Main image.
   541 INCOMPATIBILITY: all constants of the Enum theory now have to be
   542 referred to by its qualified name.
   543 
   544   enum    ~>  Enum.enum
   545   nlists  ~>  Enum.nlists
   546   product ~>  Enum.product
   547 
   548 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   549 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   550 INCOMPATIBILITY.
   551 
   552 * Theory Library/SetsAndFunctions has been split into
   553 Library/Function_Algebras and Library/Set_Algebras; canonical names
   554 for instance definitions for functions; various improvements.
   555 INCOMPATIBILITY.
   556 
   557 * Theory Library/Multiset provides stable quicksort implementation of
   558 sort_key.
   559 
   560 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   561 INCOMPATIBILITY.
   562 
   563 * Session Multivariate_Analysis: introduced a type class for euclidean
   564 space.  Most theorems are now stated in terms of euclidean spaces
   565 instead of finite cartesian products.
   566 
   567   types
   568     real ^ 'n ~>  'a::real_vector
   569               ~>  'a::euclidean_space
   570               ~>  'a::ordered_euclidean_space
   571         (depends on your needs)
   572 
   573   constants
   574      _ $ _        ~> _ $$ _
   575      \<chi> x. _  ~> \<chi>\<chi> x. _
   576      CARD('n)     ~> DIM('a)
   577 
   578 Also note that the indices are now natural numbers and not from some
   579 finite type. Finite cartesian products of euclidean spaces, products
   580 of euclidean spaces the real and complex numbers are instantiated to
   581 be euclidean_spaces.  INCOMPATIBILITY.
   582 
   583 * Session Probability: introduced pextreal as positive extended real
   584 numbers.  Use pextreal as value for measures.  Introduce the
   585 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   586 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   587 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   588 
   589 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   590 INCOMPATIBILITY.
   591 
   592 * Session SPARK (with image HOL-SPARK) provides commands to load and
   593 prove verification conditions generated by the SPARK Ada program
   594 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   595 
   596 
   597 *** HOL-Algebra ***
   598 
   599 * Theorems for additive ring operations (locale abelian_monoid and
   600 descendants) are generated by interpretation from their multiplicative
   601 counterparts.  Names (in particular theorem names) have the mandatory
   602 qualifier 'add'.  Previous theorem names are redeclared for
   603 compatibility.
   604 
   605 * Structure "int_ring" is now an abbreviation (previously a
   606 definition).  This fits more natural with advanced interpretations.
   607 
   608 
   609 *** HOLCF ***
   610 
   611 * The domain package now runs in definitional mode by default: The
   612 former command 'new_domain' is now called 'domain'.  To use the domain
   613 package in its original axiomatic mode, use 'domain (unsafe)'.
   614 INCOMPATIBILITY.
   615 
   616 * The new class "domain" is now the default sort.  Class "predomain"
   617 is an unpointed version of "domain". Theories can be updated by
   618 replacing sort annotations as shown below.  INCOMPATIBILITY.
   619 
   620   'a::type ~> 'a::countable
   621   'a::cpo  ~> 'a::predomain
   622   'a::pcpo ~> 'a::domain
   623 
   624 * The old type class "rep" has been superseded by class "domain".
   625 Accordingly, users of the definitional package must remove any
   626 "default_sort rep" declarations.  INCOMPATIBILITY.
   627 
   628 * The domain package (definitional mode) now supports unpointed
   629 predomain argument types, as long as they are marked 'lazy'. (Strict
   630 arguments must be in class "domain".) For example, the following
   631 domain definition now works:
   632 
   633   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   634 
   635 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   636 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   637 'a option, and 'a list.  Additionally, it configures fixrec and the
   638 domain package to work with these types.  For example:
   639 
   640   fixrec isInl :: "('a + 'b) u -> tr"
   641     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   642 
   643   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   644 
   645 * The "(permissive)" option of fixrec has been replaced with a
   646 per-equation "(unchecked)" option. See
   647 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   648 
   649 * The "bifinite" class no longer fixes a constant "approx"; the class
   650 now just asserts that such a function exists.  INCOMPATIBILITY.
   651 
   652 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   653 defines an embedding of type 'a defl into udom by default; instances
   654 of "bifinite" and "domain" classes are available in
   655 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   656 
   657 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   658 
   659 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   660 
   661 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   662 
   663 * The function "cprod_map" has been renamed to "prod_map".
   664 INCOMPATIBILITY.
   665 
   666 * The monadic bind operator on each powerdomain has new binder syntax
   667 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   668 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   669 
   670 * The infix syntax for binary union on each powerdomain has changed
   671 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   672 syntax.  INCOMPATIBILITY.
   673 
   674 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   675 still supported as an input translation.
   676 
   677 * Renamed some theorems (the original names are also still available).
   678 
   679   expand_fun_below   ~> fun_below_iff
   680   below_fun_ext      ~> fun_belowI
   681   expand_cfun_eq     ~> cfun_eq_iff
   682   ext_cfun           ~> cfun_eqI
   683   expand_cfun_below  ~> cfun_below_iff
   684   below_cfun_ext     ~> cfun_belowI
   685   cont2cont_Rep_CFun ~> cont2cont_APP
   686 
   687 * The Abs and Rep functions for various types have changed names.
   688 Related theorem names have also changed to match. INCOMPATIBILITY.
   689 
   690   Rep_CFun  ~> Rep_cfun
   691   Abs_CFun  ~> Abs_cfun
   692   Rep_Sprod ~> Rep_sprod
   693   Abs_Sprod ~> Abs_sprod
   694   Rep_Ssum  ~> Rep_ssum
   695   Abs_Ssum  ~> Abs_ssum
   696 
   697 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   698 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   699 
   700 * Various changes to bisimulation/coinduction with domain package:
   701 
   702   - Definitions of "bisim" constants no longer mention definedness.
   703   - With mutual recursion, "bisim" predicate is now curried.
   704   - With mutual recursion, each type gets a separate coind theorem.
   705   - Variable names in bisim_def and coinduct rules have changed.
   706 
   707 INCOMPATIBILITY.
   708 
   709 * Case combinators generated by the domain package for type "foo" are
   710 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   711 
   712 * Several theorems have been renamed to more accurately reflect the
   713 names of constants and types involved.  INCOMPATIBILITY.
   714 
   715   thelub_const    ~> lub_const
   716   lub_const       ~> is_lub_const
   717   thelubI         ~> lub_eqI
   718   is_lub_lub      ~> is_lubD2
   719   lubI            ~> is_lub_lub
   720   unique_lub      ~> is_lub_unique
   721   is_ub_lub       ~> is_lub_rangeD1
   722   lub_bin_chain   ~> is_lub_bin_chain
   723   lub_fun         ~> is_lub_fun
   724   thelub_fun      ~> lub_fun
   725   thelub_cfun     ~> lub_cfun
   726   thelub_Pair     ~> lub_Pair
   727   lub_cprod       ~> is_lub_prod
   728   thelub_cprod    ~> lub_prod
   729   minimal_cprod   ~> minimal_prod
   730   inst_cprod_pcpo ~> inst_prod_pcpo
   731   UU_I            ~> bottomI
   732   compact_UU      ~> compact_bottom
   733   deflation_UU    ~> deflation_bottom
   734   finite_deflation_UU ~> finite_deflation_bottom
   735 
   736 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   737 
   738   sq_ord_less_eq_trans ~> below_eq_trans
   739   sq_ord_eq_less_trans ~> eq_below_trans
   740   refl_less            ~> below_refl
   741   trans_less           ~> below_trans
   742   antisym_less         ~> below_antisym
   743   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   744   box_less             ~> box_below
   745   rev_trans_less       ~> rev_below_trans
   746   not_less2not_eq      ~> not_below2not_eq
   747   less_UU_iff          ~> below_UU_iff
   748   flat_less_iff        ~> flat_below_iff
   749   adm_less             ~> adm_below
   750   adm_not_less         ~> adm_not_below
   751   adm_compact_not_less ~> adm_compact_not_below
   752   less_fun_def         ~> below_fun_def
   753   expand_fun_less      ~> fun_below_iff
   754   less_fun_ext         ~> fun_belowI
   755   less_discr_def       ~> below_discr_def
   756   discr_less_eq        ~> discr_below_eq
   757   less_unit_def        ~> below_unit_def
   758   less_cprod_def       ~> below_prod_def
   759   prod_lessI           ~> prod_belowI
   760   Pair_less_iff        ~> Pair_below_iff
   761   fst_less_iff         ~> fst_below_iff
   762   snd_less_iff         ~> snd_below_iff
   763   expand_cfun_less     ~> cfun_below_iff
   764   less_cfun_ext        ~> cfun_belowI
   765   injection_less       ~> injection_below
   766   less_up_def          ~> below_up_def
   767   not_Iup_less         ~> not_Iup_below
   768   Iup_less             ~> Iup_below
   769   up_less              ~> up_below
   770   Def_inject_less_eq   ~> Def_below_Def
   771   Def_less_is_eq       ~> Def_below_iff
   772   spair_less_iff       ~> spair_below_iff
   773   less_sprod           ~> below_sprod
   774   spair_less           ~> spair_below
   775   sfst_less_iff        ~> sfst_below_iff
   776   ssnd_less_iff        ~> ssnd_below_iff
   777   fix_least_less       ~> fix_least_below
   778   dist_less_one        ~> dist_below_one
   779   less_ONE             ~> below_ONE
   780   ONE_less_iff         ~> ONE_below_iff
   781   less_sinlD           ~> below_sinlD
   782   less_sinrD           ~> below_sinrD
   783 
   784 
   785 *** FOL and ZF ***
   786 
   787 * All constant names are now qualified internally and use proper
   788 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   789 
   790 
   791 *** ML ***
   792 
   793 * Antiquotation @{assert} inlines a function bool -> unit that raises
   794 Fail if the argument is false.  Due to inlining the source position of
   795 failed assertions is included in the error output.
   796 
   797 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   798 text is in practice always evaluated with a stable theory checkpoint.
   799 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   800 
   801 * Antiquotation @{theory A} refers to theory A from the ancestry of
   802 the current context, not any accidental theory loader state as before.
   803 Potential INCOMPATIBILITY, subtle change in semantics.
   804 
   805 * Syntax.pretty_priority (default 0) configures the required priority
   806 of pretty-printed output and thus affects insertion of parentheses.
   807 
   808 * Syntax.default_root (default "any") configures the inner syntax
   809 category (nonterminal symbol) for parsing of terms.
   810 
   811 * Former exception Library.UnequalLengths now coincides with
   812 ListPair.UnequalLengths.
   813 
   814 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   815 main functionality is provided by structure Simplifier.
   816 
   817 * Renamed raw "explode" function to "raw_explode" to emphasize its
   818 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   819 almost all situations.
   820 
   821 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   822 See implementation manual for further details on exceptions in
   823 Isabelle/ML.
   824 
   825 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   826 meaning.
   827 
   828 * Renamed structure PureThy to Pure_Thy and moved most of its
   829 operations to structure Global_Theory, to emphasize that this is
   830 rarely-used global-only stuff.
   831 
   832 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   833 instead (or tracing for high-volume output).
   834 
   835 * Configuration option show_question_marks only affects regular pretty
   836 printing of types and terms, not raw Term.string_of_vname.
   837 
   838 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   839 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   840 @{thms} for most purposes.
   841 
   842 * ML structure Unsynchronized is never opened, not even in Isar
   843 interaction mode as before.  Old Unsynchronized.set etc. have been
   844 discontinued -- use plain := instead.  This should be *rare* anyway,
   845 since modern tools always work via official context data, notably
   846 configuration options.
   847 
   848 * Parallel and asynchronous execution requires special care concerning
   849 interrupts.  Structure Exn provides some convenience functions that
   850 avoid working directly with raw Interrupt.  User code must not absorb
   851 interrupts -- intermediate handling (for cleanup etc.) needs to be
   852 followed by re-raising of the original exception.  Another common
   853 source of mistakes are "handle _" patterns, which make the meaning of
   854 the program subject to physical effects of the environment.
   855 
   856 
   857 
   858 New in Isabelle2009-2 (June 2010)
   859 ---------------------------------
   860 
   861 *** General ***
   862 
   863 * Authentic syntax for *all* logical entities (type classes, type
   864 constructors, term constants): provides simple and robust
   865 correspondence between formal entities and concrete syntax.  Within
   866 the parse tree / AST representations, "constants" are decorated by
   867 their category (class, type, const) and spelled out explicitly with
   868 their full internal name.
   869 
   870 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   871 and translations (translation rules and translation functions in ML).
   872 Some hints on upgrading:
   873 
   874   - Many existing uses of 'syntax' and 'translations' can be replaced
   875     by more modern 'type_notation', 'notation' and 'abbreviation',
   876     which are independent of this issue.
   877 
   878   - 'translations' require markup within the AST; the term syntax
   879     provides the following special forms:
   880 
   881       CONST c   -- produces syntax version of constant c from context
   882       XCONST c  -- literally c, checked as constant from context
   883       c         -- literally c, if declared by 'syntax'
   884 
   885     Plain identifiers are treated as AST variables -- occasionally the
   886     system indicates accidental variables via the error "rhs contains
   887     extra variables".
   888 
   889     Type classes and type constructors are marked according to their
   890     concrete syntax.  Some old translations rules need to be written
   891     for the "type" category, using type constructor application
   892     instead of pseudo-term application of the default category
   893     "logic".
   894 
   895   - 'parse_translation' etc. in ML may use the following
   896     antiquotations:
   897 
   898       @{class_syntax c}   -- type class c within parse tree / AST
   899       @{term_syntax c}    -- type constructor c within parse tree / AST
   900       @{const_syntax c}   -- ML version of "CONST c" above
   901       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   902 
   903   - Literal types within 'typed_print_translations', i.e. those *not*
   904     represented as pseudo-terms are represented verbatim.  Use @{class
   905     c} or @{type_name c} here instead of the above syntax
   906     antiquotations.
   907 
   908 Note that old non-authentic syntax was based on unqualified base
   909 names, so all of the above "constant" names would coincide.  Recall
   910 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   911 diagnose syntax problems.
   912 
   913 * Type constructors admit general mixfix syntax, not just infix.
   914 
   915 * Concrete syntax may be attached to local entities without a proof
   916 body, too.  This works via regular mixfix annotations for 'fix',
   917 'def', 'obtain' etc. or via the explicit 'write' command, which is
   918 similar to the 'notation' command in theory specifications.
   919 
   920 * Discontinued unnamed infix syntax (legacy feature for many years) --
   921 need to specify constant name and syntax separately.  Internal ML
   922 datatype constructors have been renamed from InfixName to Infix etc.
   923 Minor INCOMPATIBILITY.
   924 
   925 * Schematic theorem statements need to be explicitly markup as such,
   926 via commands 'schematic_lemma', 'schematic_theorem',
   927 'schematic_corollary'.  Thus the relevance of the proof is made
   928 syntactically clear, which impacts performance in a parallel or
   929 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   930 
   931 * Use of cumulative prems via "!" in some proof methods has been
   932 discontinued (old legacy feature).
   933 
   934 * References 'trace_simp' and 'debug_simp' have been replaced by
   935 configuration options stored in the context. Enabling tracing (the
   936 case of debugging is similar) in proofs works via
   937 
   938   using [[trace_simp = true]]
   939 
   940 Tracing is then active for all invocations of the simplifier in
   941 subsequent goal refinement steps. Tracing may also still be enabled or
   942 disabled via the ProofGeneral settings menu.
   943 
   944 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   945 'hide_fact' replace the former 'hide' KIND command.  Minor
   946 INCOMPATIBILITY.
   947 
   948 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   949 more efficient than combinations with -q1 or -q2.
   950 
   951 
   952 *** Pure ***
   953 
   954 * Proofterms record type-class reasoning explicitly, using the
   955 "unconstrain" operation internally.  This eliminates all sort
   956 constraints from a theorem and proof, introducing explicit
   957 OFCLASS-premises.  On the proof term level, this operation is
   958 automatically applied at theorem boundaries, such that closed proofs
   959 are always free of sort constraints.  INCOMPATIBILITY for tools that
   960 inspect proof terms.
   961 
   962 * Local theory specifications may depend on extra type variables that
   963 are not present in the result type -- arguments TYPE('a) :: 'a itself
   964 are added internally.  For example:
   965 
   966   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   967 
   968 * Predicates of locales introduced by classes carry a mandatory
   969 "class" prefix.  INCOMPATIBILITY.
   970 
   971 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   972 
   973 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   974 'class' instead.
   975 
   976 * Command 'code_reflect' allows to incorporate generated ML code into
   977 runtime environment; replaces immature code_datatype antiquotation.
   978 INCOMPATIBILITY.
   979 
   980 * Code generator: simple concept for abstract datatypes obeying
   981 invariants.
   982 
   983 * Code generator: details of internal data cache have no impact on the
   984 user space functionality any longer.
   985 
   986 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   987 subgoals.  This is more appropriate for interpretations with 'where'.
   988 INCOMPATIBILITY.
   989 
   990 * Command 'example_proof' opens an empty proof body.  This allows to
   991 experiment with Isar, without producing any persistent result.
   992 
   993 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   994 within a local theory context, with explicit checking of the
   995 constructors involved (in contrast to the raw 'syntax' versions).
   996 
   997 * Commands 'types' and 'typedecl' now work within a local theory
   998 context -- without introducing dependencies on parameters or
   999 assumptions, which is not possible in Isabelle/Pure.
  1000 
  1001 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1002 within a local theory context.  Minor INCOMPATIBILITY.
  1003 
  1004 
  1005 *** HOL ***
  1006 
  1007 * Command 'typedef' now works within a local theory context -- without
  1008 introducing dependencies on parameters or assumptions, which is not
  1009 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1010 contain multiple interpretations of local typedefs (with different
  1011 non-emptiness proofs), even in a global theory context.
  1012 
  1013 * New package for quotient types.  Commands 'quotient_type' and
  1014 'quotient_definition' may be used for defining types and constants by
  1015 quotient constructions.  An example is the type of integers created by
  1016 quotienting pairs of natural numbers:
  1017 
  1018   fun
  1019     intrel :: "(nat * nat) => (nat * nat) => bool"
  1020   where
  1021     "intrel (x, y) (u, v) = (x + v = u + y)"
  1022 
  1023   quotient_type int = "nat * nat" / intrel
  1024     by (auto simp add: equivp_def expand_fun_eq)
  1025 
  1026   quotient_definition
  1027     "0::int" is "(0::nat, 0::nat)"
  1028 
  1029 The method "lifting" can be used to lift of theorems from the
  1030 underlying "raw" type to the quotient type.  The example
  1031 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1032 construction and provides a reasoning infrastructure for finite sets.
  1033 
  1034 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1035 clash with new theory Quotient in Main HOL.
  1036 
  1037 * Moved the SMT binding into the main HOL session, eliminating
  1038 separate HOL-SMT session.
  1039 
  1040 * List membership infix mem operation is only an input abbreviation.
  1041 INCOMPATIBILITY.
  1042 
  1043 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1044 for future developements; former Library/Word.thy is still present in
  1045 the AFP entry RSAPPS.
  1046 
  1047 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1048 longer shadowed.  INCOMPATIBILITY.
  1049 
  1050 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1051 INCOMPATIBILITY.
  1052 
  1053 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1054 INCOMPATIBILITY.
  1055 
  1056 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1057 instead.  INCOMPATIBILITY.
  1058 
  1059 * Dropped several real-specific versions of lemmas about floor and
  1060 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1061 instead.  INCOMPATIBILITY.
  1062 
  1063   floor_number_of_eq         ~> floor_number_of
  1064   le_floor_eq_number_of      ~> number_of_le_floor
  1065   le_floor_eq_zero           ~> zero_le_floor
  1066   le_floor_eq_one            ~> one_le_floor
  1067   floor_less_eq_number_of    ~> floor_less_number_of
  1068   floor_less_eq_zero         ~> floor_less_zero
  1069   floor_less_eq_one          ~> floor_less_one
  1070   less_floor_eq_number_of    ~> number_of_less_floor
  1071   less_floor_eq_zero         ~> zero_less_floor
  1072   less_floor_eq_one          ~> one_less_floor
  1073   floor_le_eq_number_of      ~> floor_le_number_of
  1074   floor_le_eq_zero           ~> floor_le_zero
  1075   floor_le_eq_one            ~> floor_le_one
  1076   floor_subtract_number_of   ~> floor_diff_number_of
  1077   floor_subtract_one         ~> floor_diff_one
  1078   ceiling_number_of_eq       ~> ceiling_number_of
  1079   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1080   ceiling_le_zero_eq         ~> ceiling_le_zero
  1081   ceiling_le_eq_one          ~> ceiling_le_one
  1082   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1083   less_ceiling_eq_zero       ~> zero_less_ceiling
  1084   less_ceiling_eq_one        ~> one_less_ceiling
  1085   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1086   ceiling_less_eq_zero       ~> ceiling_less_zero
  1087   ceiling_less_eq_one        ~> ceiling_less_one
  1088   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1089   le_ceiling_eq_zero         ~> zero_le_ceiling
  1090   le_ceiling_eq_one          ~> one_le_ceiling
  1091   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1092   ceiling_subtract_one       ~> ceiling_diff_one
  1093 
  1094 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1095 application of the various fold combinators on finite sets.
  1096 
  1097 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1098 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1099 implementation.  INCOMPATIBILTY.
  1100 
  1101 * Theory Library/Coinductive_List has been removed -- superseded by
  1102 AFP/thys/Coinductive.
  1103 
  1104 * Theory PReal, including the type "preal" and related operations, has
  1105 been removed.  INCOMPATIBILITY.
  1106 
  1107 * Real: new development using Cauchy Sequences.
  1108 
  1109 * Split off theory "Big_Operators" containing setsum, setprod,
  1110 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1111 
  1112 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1113 "Int" etc.  INCOMPATIBILITY.
  1114 
  1115 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1116 
  1117 * New set of rules "ac_simps" provides combined assoc / commute
  1118 rewrites for all interpretations of the appropriate generic locales.
  1119 
  1120 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1121 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1122 appropriate and more consistent names suitable for name prefixes
  1123 within the HOL theories.  INCOMPATIBILITY.
  1124 
  1125 * Some generic constants have been put to appropriate theories:
  1126   - less_eq, less: Orderings
  1127   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1128   - inverse, divide: Rings
  1129 INCOMPATIBILITY.
  1130 
  1131 * More consistent naming of type classes involving orderings (and
  1132 lattices):
  1133 
  1134     lower_semilattice                   ~> semilattice_inf
  1135     upper_semilattice                   ~> semilattice_sup
  1136 
  1137     dense_linear_order                  ~> dense_linorder
  1138 
  1139     pordered_ab_group_add               ~> ordered_ab_group_add
  1140     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1141     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1142     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1143     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1144     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1145     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1146     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1147     pordered_comm_ring                  ~> ordered_comm_ring
  1148     pordered_comm_semiring              ~> ordered_comm_semiring
  1149     pordered_ring                       ~> ordered_ring
  1150     pordered_ring_abs                   ~> ordered_ring_abs
  1151     pordered_semiring                   ~> ordered_semiring
  1152 
  1153     ordered_ab_group_add                ~> linordered_ab_group_add
  1154     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1155     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1156     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1157     ordered_field                       ~> linordered_field
  1158     ordered_field_no_lb                 ~> linordered_field_no_lb
  1159     ordered_field_no_ub                 ~> linordered_field_no_ub
  1160     ordered_field_dense_linear_order    ~> dense_linordered_field
  1161     ordered_idom                        ~> linordered_idom
  1162     ordered_ring                        ~> linordered_ring
  1163     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1164     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1165     ordered_ring_strict                 ~> linordered_ring_strict
  1166     ordered_semidom                     ~> linordered_semidom
  1167     ordered_semiring                    ~> linordered_semiring
  1168     ordered_semiring_1                  ~> linordered_semiring_1
  1169     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1170     ordered_semiring_strict             ~> linordered_semiring_strict
  1171 
  1172   The following slightly odd type classes have been moved to a
  1173   separate theory Library/Lattice_Algebras:
  1174 
  1175     lordered_ab_group_add               ~> lattice_ab_group_add
  1176     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1177     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1178     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1179     lordered_ring                       ~> lattice_ring
  1180 
  1181 INCOMPATIBILITY.
  1182 
  1183 * Refined field classes:
  1184   - classes division_ring_inverse_zero, field_inverse_zero,
  1185     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1186     subsumes former division_by_zero class;
  1187   - numerous lemmas have been ported from field to division_ring.
  1188 INCOMPATIBILITY.
  1189 
  1190 * Refined algebra theorem collections:
  1191   - dropped theorem group group_simps, use algebra_simps instead;
  1192   - dropped theorem group ring_simps, use field_simps instead;
  1193   - proper theorem collection field_simps subsumes former theorem
  1194     groups field_eq_simps and field_simps;
  1195   - dropped lemma eq_minus_self_iff which is a duplicate for
  1196     equal_neg_zero.
  1197 INCOMPATIBILITY.
  1198 
  1199 * Theory Finite_Set and List: some lemmas have been generalized from
  1200 sets to lattices:
  1201 
  1202   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1203   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1204   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1205   union_Union_fold_union        ~> sup_Sup_fold_sup
  1206   Inter_fold_inter              ~> Inf_fold_inf
  1207   Union_fold_union              ~> Sup_fold_sup
  1208   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1209   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1210   INTER_fold_inter              ~> INFI_fold_inf
  1211   UNION_fold_union              ~> SUPR_fold_sup
  1212 
  1213 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1214 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1215 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1216 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1217 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1218 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1219 
  1220 * Reorganized theory Multiset: swapped notation of pointwise and
  1221 multiset order:
  1222 
  1223   - pointwise ordering is instance of class order with standard syntax
  1224     <= and <;
  1225   - multiset ordering has syntax <=# and <#; partial order properties
  1226     are provided by means of interpretation with prefix
  1227     multiset_order;
  1228   - less duplication, less historical organization of sections,
  1229     conversion from associations lists to multisets, rudimentary code
  1230     generation;
  1231   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1232     if needed.
  1233 
  1234 Renamed:
  1235 
  1236   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1237   multi_count_ext  ~>  multiset_ext
  1238   diff_union_inverse2  ~>  diff_union_cancelR
  1239 
  1240 INCOMPATIBILITY.
  1241 
  1242 * Theory Permutation: replaced local "remove" by List.remove1.
  1243 
  1244 * Code generation: ML and OCaml code is decorated with signatures.
  1245 
  1246 * Theory List: added transpose.
  1247 
  1248 * Library/Nat_Bijection.thy is a collection of bijective functions
  1249 between nat and other types, which supersedes the older libraries
  1250 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1251 
  1252   Constants:
  1253   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1254   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1255   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1256   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1257   Countable.pair_encode           ~> prod_encode
  1258   NatIso.prod2nat                 ~> prod_encode
  1259   NatIso.nat2prod                 ~> prod_decode
  1260   NatIso.sum2nat                  ~> sum_encode
  1261   NatIso.nat2sum                  ~> sum_decode
  1262   NatIso.list2nat                 ~> list_encode
  1263   NatIso.nat2list                 ~> list_decode
  1264   NatIso.set2nat                  ~> set_encode
  1265   NatIso.nat2set                  ~> set_decode
  1266 
  1267   Lemmas:
  1268   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1269   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1270   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1271   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1272   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1273   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1274   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1275   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1276   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1277   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1278   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1279   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1280   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1281 
  1282 * Sledgehammer:
  1283   - Renamed ATP commands:
  1284     atp_info     ~> sledgehammer running_atps
  1285     atp_kill     ~> sledgehammer kill_atps
  1286     atp_messages ~> sledgehammer messages
  1287     atp_minimize ~> sledgehammer minimize
  1288     print_atps   ~> sledgehammer available_atps
  1289     INCOMPATIBILITY.
  1290   - Added user's manual ("isabelle doc sledgehammer").
  1291   - Added option syntax and "sledgehammer_params" to customize
  1292     Sledgehammer's behavior.  See the manual for details.
  1293   - Modified the Isar proof reconstruction code so that it produces
  1294     direct proofs rather than proofs by contradiction.  (This feature
  1295     is still experimental.)
  1296   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1297     full-typed mode.
  1298   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1299 
  1300 * Nitpick:
  1301   - Added and implemented "binary_ints" and "bits" options.
  1302   - Added "std" option and implemented support for nonstandard models.
  1303   - Added and implemented "finitize" option to improve the precision
  1304     of infinite datatypes based on a monotonicity analysis.
  1305   - Added support for quotient types.
  1306   - Added support for "specification" and "ax_specification"
  1307     constructs.
  1308   - Added support for local definitions (for "function" and
  1309     "termination" proofs).
  1310   - Added support for term postprocessors.
  1311   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1312   - Improved efficiency of "destroy_constrs" optimization.
  1313   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1314     record getters.
  1315   - Fixed soundness bug related to higher-order constructors.
  1316   - Fixed soundness bug when "full_descrs" is enabled.
  1317   - Improved precision of set constructs.
  1318   - Added "atoms" option.
  1319   - Added cache to speed up repeated Kodkod invocations on the same
  1320     problems.
  1321   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1322     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1323     "SAT4J_Light".  INCOMPATIBILITY.
  1324   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1325     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1326   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1327 
  1328 * Method "induct" now takes instantiations of the form t, where t is not
  1329   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1330   If this is not intended, t has to be enclosed in parentheses.
  1331   By default, the equalities generated by definitional instantiations
  1332   are pre-simplified, which may cause parameters of inductive cases
  1333   to disappear, or may even delete some of the inductive cases.
  1334   Use "induct (no_simp)" instead of "induct" to restore the old
  1335   behaviour. The (no_simp) option is also understood by the "cases"
  1336   and "nominal_induct" methods, which now perform pre-simplification, too.
  1337   INCOMPATIBILITY.
  1338 
  1339 
  1340 *** HOLCF ***
  1341 
  1342 * Variable names in lemmas generated by the domain package have
  1343 changed; the naming scheme is now consistent with the HOL datatype
  1344 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1345 
  1346 * The domain package no longer defines the function "foo_copy" for
  1347 recursive domain "foo".  The reach lemma is now stated directly in
  1348 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1349 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1350 
  1351 * Most definedness lemmas generated by the domain package (previously
  1352 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1353 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1354 Proofs that used definedness lemmas as intro rules may break,
  1355 potential INCOMPATIBILITY.
  1356 
  1357 * Induction and casedist rules generated by the domain package now
  1358 declare proper case_names (one called "bottom", and one named for each
  1359 constructor).  INCOMPATIBILITY.
  1360 
  1361 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1362 rules are generated for each domain, INCOMPATIBILITY.
  1363 
  1364   foo_bar.reach       ~> foo.reach  bar.reach
  1365   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1366 
  1367 * Some lemmas generated by the domain package have been renamed for
  1368 consistency with the datatype package, INCOMPATIBILITY.
  1369 
  1370   foo.ind        ~> foo.induct
  1371   foo.finite_ind ~> foo.finite_induct
  1372   foo.coind      ~> foo.coinduct
  1373   foo.casedist   ~> foo.exhaust
  1374   foo.exhaust    ~> foo.nchotomy
  1375 
  1376 * For consistency with other definition packages, the fixrec package
  1377 now generates qualified theorem names, INCOMPATIBILITY.
  1378 
  1379   foo_simps  ~> foo.simps
  1380   foo_unfold ~> foo.unfold
  1381   foo_induct ~> foo.induct
  1382 
  1383 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1384 method and internal fixrec proofs now use the default simpset instead.
  1385 INCOMPATIBILITY.
  1386 
  1387 * The "contlub" predicate has been removed.  Proof scripts should use
  1388 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1389 
  1390 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1391 
  1392 * The constants cpair, cfst, and csnd have been removed in favor of
  1393 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1394 
  1395 
  1396 *** ML ***
  1397 
  1398 * Antiquotations for basic formal entities:
  1399 
  1400     @{class NAME}         -- type class
  1401     @{class_syntax NAME}  -- syntax representation of the above
  1402 
  1403     @{type_name NAME}     -- logical type
  1404     @{type_abbrev NAME}   -- type abbreviation
  1405     @{nonterminal NAME}   -- type of concrete syntactic category
  1406     @{type_syntax NAME}   -- syntax representation of any of the above
  1407 
  1408     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1409     @{const_abbrev NAME}  -- abbreviated constant
  1410     @{const_syntax NAME}  -- syntax representation of any of the above
  1411 
  1412 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1413 syntax constant (cf. 'syntax' command).
  1414 
  1415 * Antiquotation @{make_string} inlines a function to print arbitrary
  1416 values similar to the ML toplevel.  The result is compiler dependent
  1417 and may fall back on "?" in certain situations.
  1418 
  1419 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1420 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1421 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1422 not work with the asynchronous Isar document model.
  1423 
  1424 * Configuration options now admit dynamic default values, depending on
  1425 the context or even global references.
  1426 
  1427 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1428 uses an efficient external library if available (for Poly/ML).
  1429 
  1430 * Renamed some important ML structures, while keeping the old names
  1431 for some time as aliases within the structure Legacy:
  1432 
  1433   OuterKeyword  ~>  Keyword
  1434   OuterLex      ~>  Token
  1435   OuterParse    ~>  Parse
  1436   OuterSyntax   ~>  Outer_Syntax
  1437   PrintMode     ~>  Print_Mode
  1438   SpecParse     ~>  Parse_Spec
  1439   ThyInfo       ~>  Thy_Info
  1440   ThyLoad       ~>  Thy_Load
  1441   ThyOutput     ~>  Thy_Output
  1442   TypeInfer     ~>  Type_Infer
  1443 
  1444 Note that "open Legacy" simplifies porting of sources, but forgetting
  1445 to remove it again will complicate porting again in the future.
  1446 
  1447 * Most operations that refer to a global context are named
  1448 accordingly, e.g. Simplifier.global_context or
  1449 ProofContext.init_global.  There are some situations where a global
  1450 context actually works, but under normal circumstances one needs to
  1451 pass the proper local context through the code!
  1452 
  1453 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1454 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1455 Pretty.pp argument to merge, which is absent in the standard
  1456 Theory_Data version.
  1457 
  1458 * Sorts.certify_sort and derived "cert" operations for types and terms
  1459 no longer minimize sorts.  Thus certification at the boundary of the
  1460 inference kernel becomes invariant under addition of class relations,
  1461 which is an important monotonicity principle.  Sorts are now minimized
  1462 in the syntax layer only, at the boundary between the end-user and the
  1463 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1464 explicitly in rare situations.
  1465 
  1466 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1467 emphasize that this is in no way a standard operation.
  1468 INCOMPATIBILITY.
  1469 
  1470 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1471 usual for resolution.  Rare INCOMPATIBILITY.
  1472 
  1473 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1474 to emphasize that these only work in a global situation (which is
  1475 quite rare).
  1476 
  1477 * Curried take and drop in library.ML; negative length is interpreted
  1478 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1479 
  1480 * Proof terms: type substitutions on proof constants now use canonical
  1481 order of type variables.  INCOMPATIBILITY for tools working with proof
  1482 terms.
  1483 
  1484 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1485 may no longer carry premises.  User-level specifications are
  1486 transformed accordingly by Thm.add_axiom/add_def.
  1487 
  1488 
  1489 *** System ***
  1490 
  1491 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1492 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1493 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1494 
  1495 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1496 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1497 respectively.
  1498 
  1499 * Old lib/scripts/polyml-platform is superseded by the
  1500 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1501 variant, even on a 64 bit machine.  The following example setting
  1502 prefers 64 bit if available:
  1503 
  1504   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1505 
  1506 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1507 Isabelle/Scala layer for advanced prover interaction and integration.
  1508 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1509 component.
  1510 
  1511 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1512 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1513 similar to the default assignment of the document preparation system
  1514 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1515 provides some operations for direct access to the font without asking
  1516 the user for manual installation.
  1517 
  1518 
  1519 
  1520 New in Isabelle2009-1 (December 2009)
  1521 -------------------------------------
  1522 
  1523 *** General ***
  1524 
  1525 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1526 one backslash should be used, even in ML sources.
  1527 
  1528 
  1529 *** Pure ***
  1530 
  1531 * Locale interpretation propagates mixins along the locale hierarchy.
  1532 The currently only available mixins are the equations used to map
  1533 local definitions to terms of the target domain of an interpretation.
  1534 
  1535 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1536 loc" to print all interpretations of locale "loc" in the theory.
  1537 Interpretations in proofs are not shown.
  1538 
  1539 * Thoroughly revised locales tutorial.  New section on conditional
  1540 interpretation.
  1541 
  1542 * On instantiation of classes, remaining undefined class parameters
  1543 are formally declared.  INCOMPATIBILITY.
  1544 
  1545 
  1546 *** Document preparation ***
  1547 
  1548 * New generalized style concept for printing terms: @{foo (style) ...}
  1549 instead of @{foo_style style ...}  (old form is still retained for
  1550 backward compatibility).  Styles can be also applied for
  1551 antiquotations prop, term_type and typeof.
  1552 
  1553 
  1554 *** HOL ***
  1555 
  1556 * New proof method "smt" for a combination of first-order logic with
  1557 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1558 fixed-size bitvectors; there is also basic support for higher-order
  1559 features (esp. lambda abstractions).  It is an incomplete decision
  1560 procedure based on external SMT solvers using the oracle mechanism;
  1561 for the SMT solver Z3, this method is proof-producing.  Certificates
  1562 are provided to avoid calling the external solvers solely for
  1563 re-checking proofs.  Due to a remote SMT service there is no need for
  1564 installing SMT solvers locally.  See src/HOL/SMT.
  1565 
  1566 * New commands to load and prove verification conditions generated by
  1567 the Boogie program verifier or derived systems (e.g. the Verifying C
  1568 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1569 
  1570 * New counterexample generator tool 'nitpick' based on the Kodkod
  1571 relational model finder.  See src/HOL/Tools/Nitpick and
  1572 src/HOL/Nitpick_Examples.
  1573 
  1574 * New commands 'code_pred' and 'values' to invoke the predicate
  1575 compiler and to enumerate values of inductive predicates.
  1576 
  1577 * A tabled implementation of the reflexive transitive closure.
  1578 
  1579 * New implementation of quickcheck uses generic code generator;
  1580 default generators are provided for all suitable HOL types, records
  1581 and datatypes.  Old quickcheck can be re-activated importing theory
  1582 Library/SML_Quickcheck.
  1583 
  1584 * New testing tool Mirabelle for automated proof tools.  Applies
  1585 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1586 every proof step in a theory.  To be used in batch mode via the
  1587 "mirabelle" utility.
  1588 
  1589 * New proof method "sos" (sum of squares) for nonlinear real
  1590 arithmetic (originally due to John Harison). It requires theory
  1591 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1592 works well in practice on quantifier-free real arithmetic with +, -,
  1593 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1594 inequalities between polynomials.  It makes use of external
  1595 semidefinite programming solvers.  Method "sos" generates a
  1596 certificate that can be pasted into the proof thus avoiding the need
  1597 to call an external tool every time the proof is checked.  See
  1598 src/HOL/Library/Sum_Of_Squares.
  1599 
  1600 * New method "linarith" invokes existing linear arithmetic decision
  1601 procedure only.
  1602 
  1603 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1604 
  1605 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1606 Causes full type information to be output to the ATPs.  This slows
  1607 ATPs down considerably but eliminates a source of unsound "proofs"
  1608 that fail later.
  1609 
  1610 * New method "metisFT": A version of metis that uses full type
  1611 information in order to avoid failures of proof reconstruction.
  1612 
  1613 * New evaluator "approximate" approximates an real valued term using
  1614 the same method as the approximation method.
  1615 
  1616 * Method "approximate" now supports arithmetic expressions as
  1617 boundaries of intervals and implements interval splitting and Taylor
  1618 series expansion.
  1619 
  1620 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1621 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1622 
  1623 * New theory SupInf of the supremum and infimum operators for sets of
  1624 reals.
  1625 
  1626 * New theory Probability, which contains a development of measure
  1627 theory, eventually leading to Lebesgue integration and probability.
  1628 
  1629 * Extended Multivariate Analysis to include derivation and Brouwer's
  1630 fixpoint theorem.
  1631 
  1632 * Reorganization of number theory, INCOMPATIBILITY:
  1633   - new number theory development for nat and int, in theories Divides
  1634     and GCD as well as in new session Number_Theory
  1635   - some constants and facts now suffixed with _nat and _int
  1636     accordingly
  1637   - former session NumberTheory now named Old_Number_Theory, including
  1638     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1639   - moved theory Pocklington from src/HOL/Library to
  1640     src/HOL/Old_Number_Theory
  1641 
  1642 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1643 lcm of finite and infinite sets. It is shown that they form a complete
  1644 lattice.
  1645 
  1646 * Class semiring_div requires superclass no_zero_divisors and proof of
  1647 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1648 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1649 generalized to class semiring_div, subsuming former theorems
  1650 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1651 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1652 INCOMPATIBILITY.
  1653 
  1654 * Refinements to lattice classes and sets:
  1655   - less default intro/elim rules in locale variant, more default
  1656     intro/elim rules in class variant: more uniformity
  1657   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1658     le_inf_iff
  1659   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1660     sup_aci)
  1661   - renamed ACI to inf_sup_aci
  1662   - new class "boolean_algebra"
  1663   - class "complete_lattice" moved to separate theory
  1664     "Complete_Lattice"; corresponding constants (and abbreviations)
  1665     renamed and with authentic syntax:
  1666     Set.Inf ~>    Complete_Lattice.Inf
  1667     Set.Sup ~>    Complete_Lattice.Sup
  1668     Set.INFI ~>   Complete_Lattice.INFI
  1669     Set.SUPR ~>   Complete_Lattice.SUPR
  1670     Set.Inter ~>  Complete_Lattice.Inter
  1671     Set.Union ~>  Complete_Lattice.Union
  1672     Set.INTER ~>  Complete_Lattice.INTER
  1673     Set.UNION ~>  Complete_Lattice.UNION
  1674   - authentic syntax for
  1675     Set.Pow
  1676     Set.image
  1677   - mere abbreviations:
  1678     Set.empty               (for bot)
  1679     Set.UNIV                (for top)
  1680     Set.inter               (for inf, formerly Set.Int)
  1681     Set.union               (for sup, formerly Set.Un)
  1682     Complete_Lattice.Inter  (for Inf)
  1683     Complete_Lattice.Union  (for Sup)
  1684     Complete_Lattice.INTER  (for INFI)
  1685     Complete_Lattice.UNION  (for SUPR)
  1686   - object-logic definitions as far as appropriate
  1687 
  1688 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1689 Un_subset_iff are explicitly deleted as default simp rules; then also
  1690 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1691 deleted to achieve the desired effect.
  1692 
  1693 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1694 rules by default any longer; the same applies to min_max.inf_absorb1
  1695 etc.  INCOMPATIBILITY.
  1696 
  1697 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1698 pred_set_conv by default.  INCOMPATIBILITY.
  1699 
  1700 * Power operations on relations and functions are now one dedicated
  1701 constant "compow" with infix syntax "^^".  Power operation on
  1702 multiplicative monoids retains syntax "^" and is now defined generic
  1703 in class power.  INCOMPATIBILITY.
  1704 
  1705 * Relation composition "R O S" now has a more standard argument order:
  1706 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1707 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1708 break, since the O_assoc rule was not rewritten like this.  Fix using
  1709 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1710 
  1711 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1712 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1713 INCOMPATIBILITY.
  1714 
  1715 * Most rules produced by inductive and datatype package have mandatory
  1716 prefixes.  INCOMPATIBILITY.
  1717 
  1718 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1719 the attribute of the same name.  Each of the theorems in the list
  1720 DERIV_intros assumes composition with an additional function and
  1721 matches a variable to the derivative, which has to be solved by the
  1722 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1723 of most elementary terms.  Former Maclauren.DERIV_tac and
  1724 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1725 INCOMPATIBILITY.
  1726 
  1727 * Code generator attributes follow the usual underscore convention:
  1728     code_unfold     replaces    code unfold
  1729     code_post       replaces    code post
  1730     etc.
  1731   INCOMPATIBILITY.
  1732 
  1733 * Renamed methods:
  1734     sizechange -> size_change
  1735     induct_scheme -> induction_schema
  1736   INCOMPATIBILITY.
  1737 
  1738 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1739 INCOMPATIBILITY, use "undefined" directly.
  1740 
  1741 * Renamed theorems:
  1742     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1743     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1744     Suc_plus1 -> Suc_eq_plus1
  1745     *anti_sym -> *antisym*
  1746     vector_less_eq_def -> vector_le_def
  1747   INCOMPATIBILITY.
  1748 
  1749 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1750 INCOMPATIBILITY.
  1751 
  1752 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1753 INCOMPATIBILITY.
  1754 
  1755 
  1756 *** HOLCF ***
  1757 
  1758 * Theory Representable defines a class "rep" of domains that are
  1759 representable (via an ep-pair) in the universal domain type "udom".
  1760 Instances are provided for all type constructors defined in HOLCF.
  1761 
  1762 * The 'new_domain' command is a purely definitional version of the
  1763 domain package, for representable domains.  Syntax is identical to the
  1764 old domain package.  The 'new_domain' package also supports indirect
  1765 recursion using previously-defined type constructors.  See
  1766 src/HOLCF/ex/New_Domain.thy for examples.
  1767 
  1768 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1769 on the left-hand side of an equation, and then performs
  1770 simplification.  Rewriting is done using rules declared with the
  1771 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1772 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1773 
  1774 * The pattern-match compiler in 'fixrec' can now handle constructors
  1775 with HOL function types.  Pattern-match combinators for the Pair
  1776 constructor are pre-configured.
  1777 
  1778 * The 'fixrec' package now produces better fixed-point induction rules
  1779 for mutually-recursive definitions:  Induction rules have conclusions
  1780 of the form "P foo bar" instead of "P <foo, bar>".
  1781 
  1782 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1783 been renamed to "below".  The name "below" now replaces "less" in many
  1784 theorem names.  (Legacy theorem names using "less" are still supported
  1785 as well.)
  1786 
  1787 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1788 patterns can be used to generate strictness rules, or to make
  1789 functions more strict (much like the bang-patterns supported by the
  1790 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1791 examples.
  1792 
  1793 
  1794 *** ML ***
  1795 
  1796 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1797 errors and run-time exceptions, including detailed source positions.
  1798 
  1799 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1800 identified entries, with some additional information such as source
  1801 position, logical grouping etc.
  1802 
  1803 * Theory and context data is now introduced by the simplified and
  1804 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1805 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1806 copy operation) is still available for some time.
  1807 
  1808 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1809 provides a high-level programming interface to synchronized state
  1810 variables with atomic update.  This works via pure function
  1811 application within a critical section -- its runtime should be as
  1812 short as possible; beware of deadlocks if critical code is nested,
  1813 either directly or indirectly via other synchronized variables!
  1814 
  1815 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1816 wraps raw ML references, explicitly indicating their non-thread-safe
  1817 behaviour.  The Isar toplevel keeps this structure open, to
  1818 accommodate Proof General as well as quick and dirty interactive
  1819 experiments with references.
  1820 
  1821 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1822 parallel tactical reasoning.
  1823 
  1824 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1825 are similar to SUBPROOF, but are slightly more flexible: only the
  1826 specified parts of the subgoal are imported into the context, and the
  1827 body tactic may introduce new subgoals and schematic variables.
  1828 
  1829 * Old tactical METAHYPS, which does not observe the proof context, has
  1830 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1831 or Subgoal.FOCUS etc.
  1832 
  1833 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1834 functors have their own ML name space there is no point to mark them
  1835 separately.)  Minor INCOMPATIBILITY.
  1836 
  1837 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1838 
  1839 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1840 INCOMPATIBILITY.
  1841 
  1842 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1843 mode, which avoids critical setmp.
  1844 
  1845 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1846 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1847 Attrib/Method.setup introduced in Isabelle2009.
  1848 
  1849 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1850 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1851 last resort.  INCOMPATIBILITY.
  1852 
  1853 * Display.pretty_thm now requires a proper context (cf. former
  1854 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1855 or even Display.pretty_thm_without_context as last resort.
  1856 INCOMPATIBILITY.
  1857 
  1858 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1859 Syntax.pretty_typ/term directly, preferably with proper context
  1860 instead of global theory.
  1861 
  1862 
  1863 *** System ***
  1864 
  1865 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1866 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1867 usedir option -q.
  1868 
  1869 * Support for additional "Isabelle components" via etc/components, see
  1870 also the system manual.
  1871 
  1872 * The isabelle makeall tool now operates on all components with
  1873 IsaMakefile, not just hardwired "logics".
  1874 
  1875 * Removed "compress" option from isabelle-process and isabelle usedir;
  1876 this is always enabled.
  1877 
  1878 * Discontinued support for Poly/ML 4.x versions.
  1879 
  1880 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1881 on a given logic image.  This requires the lighttpd webserver and is
  1882 currently supported on Linux only.
  1883 
  1884 
  1885 
  1886 New in Isabelle2009 (April 2009)
  1887 --------------------------------
  1888 
  1889 *** General ***
  1890 
  1891 * Simplified main Isabelle executables, with less surprises on
  1892 case-insensitive file-systems (such as Mac OS).
  1893 
  1894   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1895     "isatool."
  1896 
  1897   - The former "isabelle" alias for "isabelle-process" has been
  1898     removed (should rarely occur to regular users).
  1899 
  1900   - The former "isabelle-interface" and its alias "Isabelle" have been
  1901     removed (interfaces are now regular Isabelle tools).
  1902 
  1903 Within scripts and make files, the Isabelle environment variables
  1904 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1905 respectively.  (The latter are still available as legacy feature.)
  1906 
  1907 The old isabelle-interface wrapper could react in confusing ways if
  1908 the interface was uninstalled or changed otherwise.  Individual
  1909 interface tool configuration is now more explicit, see also the
  1910 Isabelle system manual.  In particular, Proof General is now available
  1911 via "isabelle emacs".
  1912 
  1913 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1914 purge installed copies of Isabelle executables and re-run "isabelle
  1915 install -p ...", or use symlinks.
  1916 
  1917 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1918 old ~/isabelle, which was slightly non-standard and apt to cause
  1919 surprises on case-insensitive file-systems (such as Mac OS).
  1920 
  1921 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1922 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1923 care is required when using older releases of Isabelle.  Note that
  1924 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1925 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1926 
  1927 * Proofs of fully specified statements are run in parallel on
  1928 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1929 a regular 4-core machine, if the initial heap space is made reasonably
  1930 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1931 
  1932 * The main reference manuals ("isar-ref", "implementation", and
  1933 "system") have been updated and extended.  Formally checked references
  1934 as hyperlinks are now available uniformly.
  1935 
  1936 
  1937 *** Pure ***
  1938 
  1939 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1940 respects.  The most important changes are listed below.  See the
  1941 Tutorial on Locales ("locales" manual) for details.
  1942 
  1943 - In locale expressions, instantiation replaces renaming.  Parameters
  1944 must be declared in a for clause.  To aid compatibility with previous
  1945 parameter inheritance, in locale declarations, parameters that are not
  1946 'touched' (instantiation position "_" or omitted) are implicitly added
  1947 with their syntax at the beginning of the for clause.
  1948 
  1949 - Syntax from abbreviations and definitions in locales is available in
  1950 locale expressions and context elements.  The latter is particularly
  1951 useful in locale declarations.
  1952 
  1953 - More flexible mechanisms to qualify names generated by locale
  1954 expressions.  Qualifiers (prefixes) may be specified in locale
  1955 expressions, and can be marked as mandatory (syntax: "name!:") or
  1956 optional (syntax "name?:").  The default depends for plain "name:"
  1957 depends on the situation where a locale expression is used: in
  1958 commands 'locale' and 'sublocale' prefixes are optional, in
  1959 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1960 implicit qualifiers derived from the parameter names of a locale are
  1961 no longer generated.
  1962 
  1963 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1964 instantiation clause in "interpretation" and "interpret" (square
  1965 brackets) is no longer available.  Use locale expressions.
  1966 
  1967 - When converting proof scripts, mandatory qualifiers in
  1968 'interpretation' and 'interpret' should be retained by default, even
  1969 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1970 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1971 in locale expressions range over a single locale instance only.
  1972 
  1973 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1974 In existing theorem specifications replace the includes element by the
  1975 respective context elements of the included locale, omitting those
  1976 that are already present in the theorem specification.  Multiple
  1977 assume elements of a locale should be replaced by a single one
  1978 involving the locale predicate.  In the proof body, declarations (most
  1979 notably theorems) may be regained by interpreting the respective
  1980 locales in the proof context as required (command "interpret").
  1981 
  1982 If using "includes" in replacement of a target solely because the
  1983 parameter types in the theorem are not as general as in the target,
  1984 consider declaring a new locale with additional type constraints on
  1985 the parameters (context element "constrains").
  1986 
  1987 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1988 
  1989 - Locale interpretation commands no longer attempt to simplify goal.
  1990 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1991 methods intro_locales and unfold_locales to clarify.
  1992 
  1993 - Locale interpretation commands no longer accept interpretation
  1994 attributes.  INCOMPATIBILITY.
  1995 
  1996 * Class declaration: so-called "base sort" must not be given in import
  1997 list any longer, but is inferred from the specification.  Particularly
  1998 in HOL, write
  1999 
  2000     class foo = ...
  2001 
  2002 instead of
  2003 
  2004     class foo = type + ...
  2005 
  2006 * Class target: global versions of theorems stemming do not carry a
  2007 parameter prefix any longer.  INCOMPATIBILITY.
  2008 
  2009 * Class 'instance' command no longer accepts attached definitions.
  2010 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2011 
  2012 * Recovered hiding of consts, which was accidentally broken in
  2013 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2014 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2015 
  2016 * Slightly more coherent Pure syntax, with updated documentation in
  2017 isar-ref manual.  Removed locales meta_term_syntax and
  2018 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2019 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2020 directly in regular applications.
  2021 
  2022 * There is a new syntactic category "float_const" for signed decimal
  2023 fractions (e.g. 123.45 or -123.45).
  2024 
  2025 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2026 interface with 'setup' command instead.
  2027 
  2028 * Command 'local_setup' is similar to 'setup', but operates on a local
  2029 theory context.
  2030 
  2031 * The 'axiomatization' command now only works within a global theory
  2032 context.  INCOMPATIBILITY.
  2033 
  2034 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2035 hypotheses.  Sorts required in the course of reasoning need to be
  2036 covered by the constraints in the initial statement, completed by the
  2037 type instance information of the background theory.  Non-trivial sort
  2038 hypotheses, which rarely occur in practice, may be specified via
  2039 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2040 
  2041   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2042 
  2043 The result contains an implicit sort hypotheses as before --
  2044 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2045 normalization.
  2046 
  2047 * Generalized Isar history, with support for linear undo, direct state
  2048 addressing etc.
  2049 
  2050 * Changed defaults for unify configuration options:
  2051 
  2052   unify_trace_bound = 50 (formerly 25)
  2053   unify_search_bound = 60 (formerly 30)
  2054 
  2055 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2056 
  2057   a) On theory merge, the last set of code equations for a particular
  2058      constant is taken (in accordance with the policy applied by other
  2059      parts of the code generator framework).
  2060 
  2061   b) Code equations stemming from explicit declarations (e.g. code
  2062      attribute) gain priority over default code equations stemming
  2063      from definition, primrec, fun etc.
  2064 
  2065 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2066 
  2067 * Unified theorem tables for both code generators.  Thus [code
  2068 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2069 
  2070 * Command 'find_consts' searches for constants based on type and name
  2071 patterns, e.g.
  2072 
  2073     find_consts "_ => bool"
  2074 
  2075 By default, matching is against subtypes, but it may be restricted to
  2076 the whole type.  Searching by name is possible.  Multiple queries are
  2077 conjunctive and queries may be negated by prefixing them with a
  2078 hyphen:
  2079 
  2080     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2081 
  2082 * New 'find_theorems' criterion "solves" matches theorems that
  2083 directly solve the current goal (modulo higher-order unification).
  2084 
  2085 * Auto solve feature for main theorem statements: whenever a new goal
  2086 is stated, "find_theorems solves" is called; any theorems that could
  2087 solve the lemma directly are listed as part of the goal state.
  2088 Cf. associated options in Proof General Isabelle settings menu,
  2089 enabled by default, with reasonable timeout for pathological cases of
  2090 higher-order unification.
  2091 
  2092 
  2093 *** Document preparation ***
  2094 
  2095 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2096 demanding keyword 'by' and supporting the full method expression
  2097 syntax just like the Isar command 'by'.
  2098 
  2099 
  2100 *** HOL ***
  2101 
  2102 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2103 points Main and Complex_Main remain as before.
  2104 
  2105 * Logic image HOL-Plain provides a minimal HOL with the most important
  2106 tools available (inductive, datatype, primrec, ...).  This facilitates
  2107 experimentation and tool development.  Note that user applications
  2108 (and library theories) should never refer to anything below theory
  2109 Main, as before.
  2110 
  2111 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2112 experimentation due to shorter build times.
  2113 
  2114 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2115 were previously part of former HOL-Complex.  Entry point Hyperreal
  2116 remains valid, but theories formerly using Complex_Main should now use
  2117 new entry point Hypercomplex.
  2118 
  2119 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2120 Posix processes.  Avoids potentially expensive forking of the ML
  2121 process.  New thread-based implementation also works on non-Unix
  2122 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2123 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2124 commands are covered in the isar-ref manual.
  2125 
  2126 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2127 sledgehammer without local ATP installation (Vampire etc.). Other
  2128 provers may be included via suitable ML wrappers, see also
  2129 src/HOL/ATP_Linkup.thy.
  2130 
  2131 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2132 menu.
  2133 
  2134 * The metis method no longer fails because the theorem is too trivial
  2135 (contains the empty clause).
  2136 
  2137 * The metis method now fails in the usual manner, rather than raising
  2138 an exception, if it determines that it cannot prove the theorem.
  2139 
  2140 * Method "coherent" implements a prover for coherent logic (see also
  2141 src/Tools/coherent.ML).
  2142 
  2143 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2144 "undefined" is the right choice to replace "arbitrary", though
  2145 logically there is no difference.  INCOMPATIBILITY.
  2146 
  2147 * Command "value" now integrates different evaluation mechanisms.  The
  2148 result of the first successful evaluation mechanism is printed.  In
  2149 square brackets a particular named evaluation mechanisms may be
  2150 specified (currently, [SML], [code] or [nbe]).  See further
  2151 src/HOL/ex/Eval_Examples.thy.
  2152 
  2153 * Normalization by evaluation now allows non-leftlinear equations.
  2154 Declare with attribute [code nbe].
  2155 
  2156 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2157 as the structured Isar versions "cases" and "induct", cf. the
  2158 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2159 are now presented as a list of individual projections
  2160 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2161 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2162 rare situations a different rule is selected --- notably nested tuple
  2163 elimination instead of former prod.exhaust: use explicit (case_tac t
  2164 rule: prod.exhaust) here.
  2165 
  2166 * Attributes "cases", "induct", "coinduct" support "del" option.
  2167 
  2168 * Removed fact "case_split_thm", which duplicates "case_split".
  2169 
  2170 * The option datatype has been moved to a new theory Option.  Renamed
  2171 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2172 
  2173 * New predicate "strict_mono" classifies strict functions on partial
  2174 orders.  With strict functions on linear orders, reasoning about
  2175 (in)equalities is facilitated by theorems "strict_mono_eq",
  2176 "strict_mono_less_eq" and "strict_mono_less".
  2177 
  2178 * Some set operations are now proper qualified constants with
  2179 authentic syntax.  INCOMPATIBILITY:
  2180 
  2181     op Int ~>   Set.Int
  2182     op Un ~>    Set.Un
  2183     INTER ~>    Set.INTER
  2184     UNION ~>    Set.UNION
  2185     Inter ~>    Set.Inter
  2186     Union ~>    Set.Union
  2187     {} ~>       Set.empty
  2188     UNIV ~>     Set.UNIV
  2189 
  2190 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2191 theory Set.
  2192 
  2193 * Auxiliary class "itself" has disappeared -- classes without any
  2194 parameter are treated as expected by the 'class' command.
  2195 
  2196 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2197 
  2198 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2199 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2200 
  2201 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2202 method "approximation".  It proves formulas on real values by using
  2203 interval arithmetic.  In the formulas are also the transcendental
  2204 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2205 allowed. For examples see
  2206 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2207 
  2208 * Theory "Reflection" now resides in HOL/Library.
  2209 
  2210 * Entry point to Word library now simply named "Word".
  2211 INCOMPATIBILITY.
  2212 
  2213 * Made source layout more coherent with logical distribution
  2214 structure:
  2215 
  2216     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2217     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2218     src/HOL/Library/GCD.thy ~> src/HOL/
  2219     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2220     src/HOL/Library/Parity.thy ~> src/HOL/
  2221     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2222     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2223     src/HOL/Real/Lubs.thy ~> src/HOL/
  2224     src/HOL/Real/PReal.thy ~> src/HOL/
  2225     src/HOL/Real/Rational.thy ~> src/HOL/
  2226     src/HOL/Real/RComplete.thy ~> src/HOL/
  2227     src/HOL/Real/RealDef.thy ~> src/HOL/
  2228     src/HOL/Real/RealPow.thy ~> src/HOL/
  2229     src/HOL/Real/Real.thy ~> src/HOL/
  2230     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2231     src/HOL/Complex/Complex.thy ~> src/HOL/
  2232     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2233     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2234     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2235     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2236     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2237     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2238     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2239     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2240     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2241     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2242     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2243     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2244     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2245     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2246     src/HOL/Real/Float ~> src/HOL/Library/
  2247     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2248     src/HOL/Real/RealVector.thy ~> src/HOL/
  2249 
  2250     src/HOL/arith_data.ML ~> src/HOL/Tools
  2251     src/HOL/hologic.ML ~> src/HOL/Tools
  2252     src/HOL/simpdata.ML ~> src/HOL/Tools
  2253     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2254     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2255     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2256     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2257     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2258     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2259     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2260 
  2261     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2262     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2263     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2264     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2265     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2266     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2267 
  2268 * If methods "eval" and "evaluation" encounter a structured proof
  2269 state with !!/==>, only the conclusion is evaluated to True (if
  2270 possible), avoiding strange error messages.
  2271 
  2272 * Method "sizechange" automates termination proofs using (a
  2273 modification of) the size-change principle.  Requires SAT solver.  See
  2274 src/HOL/ex/Termination.thy for examples.
  2275 
  2276 * Simplifier: simproc for let expressions now unfolds if bound
  2277 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2278 
  2279 * Method "arith": Linear arithmetic now ignores all inequalities when
  2280 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2281 
  2282 * New attribute "arith" for facts that should always be used
  2283 automatically by arithmetic. It is intended to be used locally in
  2284 proofs, e.g.
  2285 
  2286   assumes [arith]: "x > 0"
  2287 
  2288 Global usage is discouraged because of possible performance impact.
  2289 
  2290 * New classes "top" and "bot" with corresponding operations "top" and
  2291 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2292 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2293 
  2294 * Changed definition lemma "less_fun_def" in order to provide an
  2295 instance for preorders on functions; use lemma "less_le" instead.
  2296 INCOMPATIBILITY.
  2297 
  2298 * Theory Orderings: class "wellorder" moved here, with explicit
  2299 induction rule "less_induct" as assumption.  For instantiation of
  2300 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2301 INCOMPATIBILITY.
  2302 
  2303 * Theory Orderings: added class "preorder" as superclass of "order".
  2304 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2305 etc. slightly changed.  Some theorems named order_class.* now named
  2306 preorder_class.*.
  2307 
  2308 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2309 "diag" to "Id_on".
  2310 
  2311 * Theory Finite_Set: added a new fold combinator of type
  2312 
  2313   ('a => 'b => 'b) => 'b => 'a set => 'b
  2314 
  2315 Occasionally this is more convenient than the old fold combinator
  2316 which is now defined in terms of the new one and renamed to
  2317 fold_image.
  2318 
  2319 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2320 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2321 extended with further lemmas!).  At the moment both still exist but
  2322 the former will disappear at some point.
  2323 
  2324 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2325 class recpower.  Type-specific simp rules for various recpower types
  2326 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2327 
  2328 rat_power_0    -> power_0
  2329 rat_power_Suc  -> power_Suc
  2330 realpow_0      -> power_0
  2331 realpow_Suc    -> power_Suc
  2332 complexpow_0   -> power_0
  2333 complexpow_Suc -> power_Suc
  2334 power_poly_0   -> power_0
  2335 power_poly_Suc -> power_Suc
  2336 
  2337 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2338 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2339 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2340 of lemmas from Divides has been generalized from nat to class
  2341 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2342 renames resulting from duplicate elimination:
  2343 
  2344     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2345     zero_dvd_iff ~>         dvd_0_left_iff
  2346     dvd_0 ~>                dvd_0_right
  2347     DIVISION_BY_ZERO_DIV ~> div_by_0
  2348     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2349     mult_div ~>             div_mult_self2_is_id
  2350     mult_mod ~>             mod_mult_self2_is_0
  2351 
  2352 * Theory IntDiv: removed many lemmas that are instances of class-based
  2353 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2354 rename old lemmas as follows:
  2355 
  2356 dvd_diff               -> nat_dvd_diff
  2357 dvd_zminus_iff         -> dvd_minus_iff
  2358 mod_add1_eq            -> mod_add_eq
  2359 mod_mult1_eq           -> mod_mult_right_eq
  2360 mod_mult1_eq'          -> mod_mult_left_eq
  2361 mod_mult_distrib_mod   -> mod_mult_eq
  2362 nat_mod_add_left_eq    -> mod_add_left_eq
  2363 nat_mod_add_right_eq   -> mod_add_right_eq
  2364 nat_mod_div_trivial    -> mod_div_trivial
  2365 nat_mod_mod_trivial    -> mod_mod_trivial
  2366 zdiv_zadd_self1        -> div_add_self1
  2367 zdiv_zadd_self2        -> div_add_self2
  2368 zdiv_zmult_self1       -> div_mult_self2_is_id
  2369 zdiv_zmult_self2       -> div_mult_self1_is_id
  2370 zdvd_triv_left         -> dvd_triv_left
  2371 zdvd_triv_right        -> dvd_triv_right
  2372 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2373 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2374 zmod_zadd_left_eq      -> mod_add_left_eq
  2375 zmod_zadd_right_eq     -> mod_add_right_eq
  2376 zmod_zadd_self1        -> mod_add_self1
  2377 zmod_zadd_self2        -> mod_add_self2
  2378 zmod_zadd1_eq          -> mod_add_eq
  2379 zmod_zdiff1_eq         -> mod_diff_eq
  2380 zmod_zdvd_zmod         -> mod_mod_cancel
  2381 zmod_zmod_cancel       -> mod_mod_cancel
  2382 zmod_zmult_self1       -> mod_mult_self2_is_0
  2383 zmod_zmult_self2       -> mod_mult_self1_is_0
  2384 zmod_1                 -> mod_by_1
  2385 zdiv_1                 -> div_by_1
  2386 zdvd_abs1              -> abs_dvd_iff
  2387 zdvd_abs2              -> dvd_abs_iff
  2388 zdvd_refl              -> dvd_refl
  2389 zdvd_trans             -> dvd_trans
  2390 zdvd_zadd              -> dvd_add
  2391 zdvd_zdiff             -> dvd_diff
  2392 zdvd_zminus_iff        -> dvd_minus_iff
  2393 zdvd_zminus2_iff       -> minus_dvd_iff
  2394 zdvd_zmultD            -> dvd_mult_right
  2395 zdvd_zmultD2           -> dvd_mult_left
  2396 zdvd_zmult_mono        -> mult_dvd_mono
  2397 zdvd_0_right           -> dvd_0_right
  2398 zdvd_0_left            -> dvd_0_left_iff
  2399 zdvd_1_left            -> one_dvd
  2400 zminus_dvd_iff         -> minus_dvd_iff
  2401 
  2402 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2403 
  2404 * The real numbers offer decimal input syntax: 12.34 is translated
  2405 into 1234/10^2. This translation is not reversed upon output.
  2406 
  2407 * Theory Library/Polynomial defines an abstract type 'a poly of
  2408 univariate polynomials with coefficients of type 'a.  In addition to
  2409 the standard ring operations, it also supports div and mod.  Code
  2410 generation is also supported, using list-style constructors.
  2411 
  2412 * Theory Library/Inner_Product defines a class of real_inner for real
  2413 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2414 => real.  Class real_inner is a subclass of real_normed_vector from
  2415 theory RealVector.
  2416 
  2417 * Theory Library/Product_Vector provides instances for the product
  2418 type 'a * 'b of several classes from RealVector and Inner_Product.
  2419 Definitions of addition, subtraction, scalar multiplication, norms,
  2420 and inner products are included.
  2421 
  2422 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2423 addition to the field operations, numerals and case syntax are also
  2424 supported.
  2425 
  2426 * Theory Library/Diagonalize provides constructive version of Cantor's
  2427 first diagonalization argument.
  2428 
  2429 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2430 zlcm (for int); carried together from various gcd/lcm developements in
  2431 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2432 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2433 may recover tupled syntax as follows:
  2434 
  2435     hide (open) const gcd
  2436     abbreviation gcd where
  2437       "gcd == (%(a, b). GCD.gcd a b)"
  2438     notation (output)
  2439       GCD.gcd ("gcd '(_, _')")
  2440 
  2441 The same works for lcm, zgcd, zlcm.
  2442 
  2443 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2444 instantiations for algebraic structures.  Removed some duplicate
  2445 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2446 
  2447 * ML antiquotation @{code} takes a constant as argument and generates
  2448 corresponding code in background and inserts name of the corresponding
  2449 resulting ML value/function/datatype constructor binding in place.
  2450 All occurrences of @{code} with a single ML block are generated
  2451 simultaneously.  Provides a generic and safe interface for
  2452 instrumentalizing code generation.  See
  2453 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2454 In future you ought to refrain from ad-hoc compiling generated SML
  2455 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2456 cannot refer to constants for which user-defined serializations are
  2457 set.  Refer to the corresponding ML counterpart directly in that
  2458 cases.
  2459 
  2460 * Command 'rep_datatype': instead of theorem names the command now
  2461 takes a list of terms denoting the constructors of the type to be
  2462 represented as datatype.  The characteristic theorems have to be
  2463 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2464 have disappeared in favour of existing ones:
  2465 
  2466     unit_induct                 ~> unit.induct
  2467     prod_induct                 ~> prod.induct
  2468     sum_induct                  ~> sum.induct
  2469     Suc_Suc_eq                  ~> nat.inject
  2470     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2471 
  2472 
  2473 *** HOL-Algebra ***
  2474 
  2475 * New locales for orders and lattices where the equivalence relation
  2476 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2477 locales use a record structure with field eq for the equivalence.
  2478 
  2479 * New theory of factorial domains.
  2480 
  2481 * Units_l_inv and Units_r_inv are now simp rules by default.
  2482 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2483 and/or r_inv will now also require deletion of these lemmas.
  2484 
  2485 * Renamed the following theorems, INCOMPATIBILITY:
  2486 
  2487 UpperD ~> Upper_memD
  2488 LowerD ~> Lower_memD
  2489 least_carrier ~> least_closed
  2490 greatest_carrier ~> greatest_closed
  2491 greatest_Lower_above ~> greatest_Lower_below
  2492 one_zero ~> carrier_one_zero
  2493 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2494 
  2495 
  2496 *** HOL-Nominal ***
  2497 
  2498 * Nominal datatypes can now contain type-variables.
  2499 
  2500 * Commands 'nominal_inductive' and 'equivariance' work with local
  2501 theory targets.
  2502 
  2503 * Nominal primrec can now works with local theory targets and its
  2504 specification syntax now conforms to the general format as seen in
  2505 'inductive' etc.
  2506 
  2507 * Method "perm_simp" honours the standard simplifier attributes
  2508 (no_asm), (no_asm_use) etc.
  2509 
  2510 * The new predicate #* is defined like freshness, except that on the
  2511 left hand side can be a set or list of atoms.
  2512 
  2513 * Experimental command 'nominal_inductive2' derives strong induction
  2514 principles for inductive definitions.  In contrast to
  2515 'nominal_inductive', which can only deal with a fixed number of
  2516 binders, it can deal with arbitrary expressions standing for sets of
  2517 atoms to be avoided.  The only inductive definition we have at the
  2518 moment that needs this generalisation is the typing rule for Lets in
  2519 the algorithm W:
  2520 
  2521  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2522  -----------------------------------------------------------------
  2523          Gamma |- Let x be t1 in t2 : T2
  2524 
  2525 In this rule one wants to avoid all the binders that are introduced by
  2526 "close Gamma T1".  We are looking for other examples where this
  2527 feature might be useful.  Please let us know.
  2528 
  2529 
  2530 *** HOLCF ***
  2531 
  2532 * Reimplemented the simplification procedure for proving continuity
  2533 subgoals.  The new simproc is extensible; users can declare additional
  2534 continuity introduction rules with the attribute [cont2cont].
  2535 
  2536 * The continuity simproc now uses a different introduction rule for
  2537 solving continuity subgoals on terms with lambda abstractions.  In
  2538 some rare cases the new simproc may fail to solve subgoals that the
  2539 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2540 Potential INCOMPATIBILITY.
  2541 
  2542 * Command 'fixrec': specification syntax now conforms to the general
  2543 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2544 examples.  INCOMPATIBILITY.
  2545 
  2546 
  2547 *** ZF ***
  2548 
  2549 * Proof of Zorn's Lemma for partial orders.
  2550 
  2551 
  2552 *** ML ***
  2553 
  2554 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2555 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2556 depends on multithreading, so timouts will not work before Poly/ML
  2557 5.2.1!
  2558 
  2559 * High-level support for concurrent ML programming, see
  2560 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2561 particularly convenient to organize independent functional
  2562 computations.  The concept of "synchronized variables" provides a
  2563 higher-order interface for components with shared state, avoiding the
  2564 delicate details of mutexes and condition variables.  (Requires
  2565 Poly/ML 5.2.1 or later.)
  2566 
  2567 * ML bindings produced via Isar commands are stored within the Isar
  2568 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2569 become thread-safe and work with undo as expected (concerning
  2570 top-level bindings, not side-effects on global references).
  2571 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2572 compiler at runtime; really global bindings need to be given outside a
  2573 theory.  (Requires Poly/ML 5.2 or later.)
  2574 
  2575 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2576 context.  Top-level ML bindings are stored within the proof context in
  2577 a purely sequential fashion, disregarding the nested proof structure.
  2578 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2579 proof.  (Requires Poly/ML 5.2 or later.)
  2580 
  2581 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2582 and Method.setup, as well as Isar commands 'attribute_setup' and
  2583 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2584 existing code accordingly, or use plain 'setup' together with old
  2585 Method.add_method.
  2586 
  2587 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2588 to 'a -> thm, while results are always tagged with an authentic oracle
  2589 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2590 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2591 accordingly.  Note that extra performance may be gained by producing
  2592 the cterm carefully, avoiding slow Thm.cterm_of.
  2593 
  2594 * Simplified interface for defining document antiquotations via
  2595 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2596 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2597 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2598 examples.
  2599 
  2600 * More systematic treatment of long names, abstract name bindings, and
  2601 name space operations.  Basic operations on qualified names have been
  2602 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2603 Long_Name.append.  Old type bstring has been mostly replaced by
  2604 abstract type binding (see structure Binding), which supports precise
  2605 qualification by packages and local theory targets, as well as proper
  2606 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2607 bstring values into Binding.name, or better pass through abstract
  2608 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2609 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2610 
  2611 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2612 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2613 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2614 
  2615 * Disposed old type and term read functions (Sign.read_def_typ,
  2616 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2617 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2618 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2619 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2620 resort for legacy applications.
  2621 
  2622 * Disposed old declarations, tactics, tactic combinators that refer to
  2623 the simpset or claset of an implicit theory (such as Addsimps,
  2624 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2625 embedded ML text, or local_simpset_of with a proper context passed as
  2626 explicit runtime argument.
  2627 
  2628 * Rules and tactics that read instantiations (read_instantiate,
  2629 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2630 context, which is required for parsing and type-checking.  Moreover,
  2631 the variables are specified as plain indexnames, not string encodings
  2632 thereof.  INCOMPATIBILITY.
  2633 
  2634 * Generic Toplevel.add_hook interface allows to analyze the result of
  2635 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2636 for theorem dependency output of transactions resulting in a new
  2637 theory state.
  2638 
  2639 * ML antiquotations: block-structured compilation context indicated by
  2640 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2641 
  2642   @{binding name}                         - basic name binding
  2643   @{let ?pat = term}                      - term abbreviation (HO matching)
  2644   @{note name = fact}                     - fact abbreviation
  2645   @{thm fact}                             - singleton fact (with attributes)
  2646   @{thms fact}                            - general fact (with attributes)
  2647   @{lemma prop by method}                 - singleton goal
  2648   @{lemma prop by meth1 meth2}            - singleton goal
  2649   @{lemma prop1 ... propN by method}      - general goal
  2650   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2651   @{lemma (open) ...}                     - open derivation
  2652 
  2653 
  2654 *** System ***
  2655 
  2656 * The Isabelle "emacs" tool provides a specific interface to invoke
  2657 Proof General / Emacs, with more explicit failure if that is not
  2658 installed (the old isabelle-interface script silently falls back on
  2659 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2660 installation location of the Proof General distribution.
  2661 
  2662 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2663 the Isabelle process into a JVM/Scala application.  See
  2664 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2665 process wrapper has been discontinued.)
  2666 
  2667 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2668 
  2669 * Various status messages (with exact source position information) are
  2670 emitted, if proper markup print mode is enabled.  This allows
  2671 user-interface components to provide detailed feedback on internal
  2672 prover operations.
  2673 
  2674 
  2675 
  2676 New in Isabelle2008 (June 2008)
  2677 -------------------------------
  2678 
  2679 *** General ***
  2680 
  2681 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2682 and updated, with formally checked references as hyperlinks.
  2683 
  2684 * Theory loader: use_thy (and similar operations) no longer set the
  2685 implicit ML context, which was occasionally hard to predict and in
  2686 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2687 provides a proper context already.
  2688 
  2689 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2690 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2691 'use' within a theory file will do the job.
  2692 
  2693 * Name space merge now observes canonical order, i.e. the second space
  2694 is inserted into the first one, while existing entries in the first
  2695 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2696 swap theory imports.
  2697 
  2698 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2699 INCOMPATIBILITY in identifier syntax etc.
  2700 
  2701 * Outer syntax: string tokens no longer admit escaped white space,
  2702 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2703 white space without escapes.
  2704 
  2705 * Outer syntax: string tokens may contain arbitrary character codes
  2706 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2707 "foo_bar".
  2708 
  2709 
  2710 *** Pure ***
  2711 
  2712 * Context-dependent token translations.  Default setup reverts locally
  2713 fixed variables, and adds hilite markup for undeclared frees.
  2714 
  2715 * Unused theorems can be found using the new command 'unused_thms'.
  2716 There are three ways of invoking it:
  2717 
  2718 (1) unused_thms
  2719      Only finds unused theorems in the current theory.
  2720 
  2721 (2) unused_thms thy_1 ... thy_n -
  2722      Finds unused theorems in the current theory and all of its ancestors,
  2723      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2724 
  2725 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2726      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2727      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2728      their ancestors.
  2729 
  2730 In order to increase the readability of the list produced by
  2731 unused_thms, theorems that have been created by a particular instance
  2732 of a theory command such as 'inductive' or 'function' are considered
  2733 to belong to the same "group", meaning that if at least one theorem in
  2734 this group is used, the other theorems in the same group are no longer
  2735 reported as unused.  Moreover, if all theorems in the group are
  2736 unused, only one theorem in the group is displayed.
  2737 
  2738 Note that proof objects have to be switched on in order for
  2739 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2740 usually the case when using Proof General with the default settings).
  2741 
  2742 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2743 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2744 duplicate fact bindings, or even accidental fact duplications.  Note
  2745 that tools may maintain dynamically scoped facts systematically, using
  2746 PureThy.add_thms_dynamic.
  2747 
  2748 * Command 'hide' now allows to hide from "fact" name space as well.
  2749 
  2750 * Eliminated destructive theorem database, simpset, claset, and
  2751 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2752 update of theories within ML code.
  2753 
  2754 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2755 INCOMPATIBILITY, object-logics depending on former Pure require
  2756 additional setup PureThy.old_appl_syntax_setup; object-logics
  2757 depending on former CPure need to refer to Pure.
  2758 
  2759 * Commands 'use' and 'ML' are now purely functional, operating on
  2760 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2761 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2762 INCOMPATIBILITY.
  2763 
  2764 * Command 'setup': discontinued implicit version with ML reference.
  2765 
  2766 * Instantiation target allows for simultaneous specification of class
  2767 instance operations together with an instantiation proof.
  2768 Type-checking phase allows to refer to class operations uniformly.
  2769 See src/HOL/Complex/Complex.thy for an Isar example and
  2770 src/HOL/Library/Eval.thy for an ML example.
  2771 
  2772 * Indexing of literal facts: be more serious about including only
  2773 facts from the visible specification/proof context, but not the
  2774 background context (locale etc.).  Affects `prop` notation and method
  2775 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2776 situations.
  2777 
  2778 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2779 "(open)" option, which used to expose internal bound variables to the
  2780 proof text.
  2781 
  2782 * Isar statements: removed obsolete case "rule_context".
  2783 INCOMPATIBILITY, better use explicit fixes/assumes.
  2784 
  2785 * Locale proofs: default proof step now includes 'unfold_locales';
  2786 hence 'proof' without argument may be used to unfold locale
  2787 predicates.
  2788 
  2789 
  2790 *** Document preparation ***
  2791 
  2792 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2793 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2794 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2795 spot); renamed link color from "darkblue" to "linkcolor" (default
  2796 value unchanged, can be redefined via \definecolor); no longer sets
  2797 "a4paper" option (unnecessary or even intrusive).
  2798 
  2799 * Antiquotation @{lemma A method} proves proposition A by the given
  2800 method (either a method name or a method name plus (optional) method
  2801 arguments in parentheses) and prints A just like @{prop A}.
  2802 
  2803 
  2804 *** HOL ***
  2805 
  2806 * New primrec package.  Specification syntax conforms in style to
  2807 definition/function/....  No separate induction rule is provided.  The
  2808 "primrec" command distinguishes old-style and new-style specifications
  2809 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2810 When adjusting theories, beware: constants stemming from new-style
  2811 primrec specifications have authentic syntax.
  2812 
  2813 * Metis prover is now an order of magnitude faster, and also works
  2814 with multithreading.
  2815 
  2816 * Metis: the maximum number of clauses that can be produced from a
  2817 theorem is now given by the attribute max_clauses.  Theorems that
  2818 exceed this number are ignored, with a warning printed.
  2819 
  2820 * Sledgehammer no longer produces structured proofs by default. To
  2821 enable, declare [[sledgehammer_full = true]].  Attributes
  2822 reconstruction_modulus, reconstruction_sorts renamed
  2823 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2824 
  2825 * Method "induct_scheme" derives user-specified induction rules
  2826 from well-founded induction and completeness of patterns. This factors
  2827 out some operations that are done internally by the function package
  2828 and makes them available separately.  See
  2829 src/HOL/ex/Induction_Scheme.thy for examples.
  2830 
  2831 * More flexible generation of measure functions for termination
  2832 proofs: Measure functions can be declared by proving a rule of the
  2833 form "is_measure f" and giving it the [measure_function] attribute.
  2834 The "is_measure" predicate is logically meaningless (always true), and
  2835 just guides the heuristic.  To find suitable measure functions, the
  2836 termination prover sets up the goal "is_measure ?f" of the appropriate
  2837 type and generates all solutions by prolog-style backwards proof using
  2838 the declared rules.
  2839 
  2840 This setup also deals with rules like 
  2841 
  2842   "is_measure f ==> is_measure (list_size f)"
  2843 
  2844 which accommodates nested datatypes that recurse through lists.
  2845 Similar rules are predeclared for products and option types.
  2846 
  2847 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2848 
  2849   INCOMPATIBILITIES:
  2850 
  2851   - Definitions of overloaded constants on sets have to be replaced by
  2852     definitions on => and bool.
  2853 
  2854   - Some definitions of overloaded operators on sets can now be proved
  2855     using the definitions of the operators on => and bool.  Therefore,
  2856     the following theorems have been renamed:
  2857 
  2858       subset_def   -> subset_eq
  2859       psubset_def  -> psubset_eq
  2860       set_diff_def -> set_diff_eq
  2861       Compl_def    -> Compl_eq
  2862       Sup_set_def  -> Sup_set_eq
  2863       Inf_set_def  -> Inf_set_eq
  2864       sup_set_def  -> sup_set_eq
  2865       inf_set_def  -> inf_set_eq
  2866 
  2867   - Due to the incompleteness of the HO unification algorithm, some
  2868     rules such as subst may require manual instantiation, if some of
  2869     the unknowns in the rule is a set.
  2870 
  2871   - Higher order unification and forward proofs:
  2872     The proof pattern
  2873 
  2874       have "P (S::'a set)" <...>
  2875       then have "EX S. P S" ..
  2876 
  2877     no longer works (due to the incompleteness of the HO unification
  2878     algorithm) and must be replaced by the pattern
  2879 
  2880       have "EX S. P S"
  2881       proof
  2882         show "P S" <...>
  2883       qed
  2884 
  2885   - Calculational reasoning with subst (or similar rules):
  2886     The proof pattern
  2887 
  2888       have "P (S::'a set)" <...>
  2889       also have "S = T" <...>
  2890       finally have "P T" .
  2891 
  2892     no longer works (for similar reasons as the previous example) and
  2893     must be replaced by something like
  2894 
  2895       have "P (S::'a set)" <...>
  2896       moreover have "S = T" <...>
  2897       ultimately have "P T" by simp
  2898 
  2899   - Tactics or packages written in ML code:
  2900     Code performing pattern matching on types via
  2901 
  2902       Type ("set", [T]) => ...
  2903 
  2904     must be rewritten. Moreover, functions like strip_type or
  2905     binder_types no longer return the right value when applied to a
  2906     type of the form
  2907 
  2908       T1 => ... => Tn => U => bool
  2909 
  2910     rather than
  2911 
  2912       T1 => ... => Tn => U set
  2913 
  2914 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2915 Wellfounded_Relations to theory Wellfounded.
  2916 
  2917 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2918 
  2919 * Class finite no longer treats UNIV as class parameter.  Use class
  2920 enum from theory Library/Enum instead to achieve a similar effect.
  2921 INCOMPATIBILITY.
  2922 
  2923 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2924 and "Cons".  INCOMPATIBILITY.
  2925 
  2926 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2927 Potential INCOMPATIBILITY.
  2928 
  2929 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2930 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2931 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2932 
  2933 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2934 the same name in theory Orderings:
  2935 
  2936   less_trans
  2937   less_linear
  2938   le_imp_less_or_eq
  2939   le_less_trans
  2940   less_le_trans
  2941   less_not_sym
  2942   less_asym
  2943 
  2944 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2945 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2946 and different variable names.
  2947 
  2948 * Library/Option_ord.thy: Canonical order on option type.
  2949 
  2950 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2951 finite maps.
  2952 
  2953 * Library/Countable.thy: Type class for countable types.
  2954 
  2955 * Theory Int: The representation of numerals has changed.  The infix
  2956 operator BIT and the bit datatype with constructors B0 and B1 have
  2957 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2958 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2959 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2960 accordingly.
  2961 
  2962 * Theory Nat: definition of <= and < on natural numbers no longer
  2963 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2964 le_def and less_def have disappeared.  Consider lemmas not_less
  2965 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2966 
  2967 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2968 (whose purpose mainly is for various fold_set functionals) have been
  2969 abandoned in favor of the existing algebraic classes
  2970 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2971 lower_semilattice (resp. upper_semilattice) and linorder.
  2972 INCOMPATIBILITY.
  2973 
  2974 * Theory Transitive_Closure: induct and cases rules now declare proper
  2975 case_names ("base" and "step").  INCOMPATIBILITY.
  2976 
  2977 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2978 lattices.  The form set-specific version is available as
  2979 Inductive.lfp_ordinal_induct_set.
  2980 
  2981 * Renamed theorems "power.simps" to "power_int.simps".
  2982 INCOMPATIBILITY.
  2983 
  2984 * Class semiring_div provides basic abstract properties of semirings
  2985 with division and modulo operations.  Subsumes former class dvd_mod.
  2986 
  2987 * Merged theories IntDef, Numeral and IntArith into unified theory
  2988 Int.  INCOMPATIBILITY.
  2989 
  2990 * Theory Library/Code_Index: type "index" now represents natural
  2991 numbers rather than integers.  INCOMPATIBILITY.
  2992 
  2993 * New class "uminus" with operation "uminus" (split of from class
  2994 "minus" which now only has operation "minus", binary).
  2995 INCOMPATIBILITY.
  2996 
  2997 * Constants "card", "internal_split", "option_map" now with authentic
  2998 syntax.  INCOMPATIBILITY.
  2999 
  3000 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3001 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3002 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3003 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3004 Sup_set_def, le_def, less_def, option_map_def now with object
  3005 equality.  INCOMPATIBILITY.
  3006 
  3007 * Records. Removed K_record, and replaced it by pure lambda term
  3008 %x. c. The simplifier setup is now more robust against eta expansion.
  3009 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3010 
  3011 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3012 
  3013 * Library/ListVector: new theory of arithmetic vector operations.
  3014 
  3015 * Library/Order_Relation: new theory of various orderings as sets of
  3016 pairs.  Defines preorders, partial orders, linear orders and
  3017 well-orders on sets and on types.
  3018 
  3019 
  3020 *** ZF ***
  3021 
  3022 * Renamed some theories to allow to loading both ZF and HOL in the
  3023 same session:
  3024 
  3025   Datatype  -> Datatype_ZF
  3026   Inductive -> Inductive_ZF
  3027   Int       -> Int_ZF
  3028   IntDiv    -> IntDiv_ZF
  3029   Nat       -> Nat_ZF
  3030   List      -> List_ZF
  3031   Main      -> Main_ZF
  3032 
  3033 INCOMPATIBILITY: ZF theories that import individual theories below
  3034 Main might need to be adapted.  Regular theory Main is still
  3035 available, as trivial extension of Main_ZF.
  3036 
  3037 
  3038 *** ML ***
  3039 
  3040 * ML within Isar: antiquotation @{const name} or @{const
  3041 name(typargs)} produces statically-checked Const term.
  3042 
  3043 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3044 (of the same name).  Removed obsolete print command.
  3045 
  3046 * Removed obsolete "use_legacy_bindings" function.
  3047 
  3048 * The ``print mode'' is now a thread-local value derived from a global
  3049 template (the former print_mode reference), thus access becomes
  3050 non-critical.  The global print_mode reference is for session
  3051 management only; user-code should use print_mode_value,
  3052 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3053 
  3054 * Functions system/system_out provide a robust way to invoke external
  3055 shell commands, with propagation of interrupts (requires Poly/ML
  3056 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3057 
  3058 
  3059 *** System ***
  3060 
  3061 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3062 in accordance with Proof General 3.7, which prefers GNU emacs.
  3063 
  3064 * isatool tty runs Isabelle process with plain tty interaction;
  3065 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3066 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3067 
  3068 * isatool browser now works with Cygwin as well, using general
  3069 "javapath" function defined in Isabelle process environment.
  3070 
  3071 * YXML notation provides a simple and efficient alternative to
  3072 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3073 isatool yxml as described in the Isabelle system manual.
  3074 
  3075 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3076 provides general wrapper for managing an Isabelle process in a robust
  3077 fashion, with ``cooked'' output from stdin/stderr.
  3078 
  3079 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3080 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3081 
  3082 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3083 way of changing the user's settings is via
  3084 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3085 script.
  3086 
  3087 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3088 cores of the underlying machine, which is a good starting point for
  3089 optimal performance tuning.  The corresponding usedir option -M allows
  3090 "max" as an alias for "0".  WARNING: does not work on certain versions
  3091 of Mac OS (with Poly/ML 5.1).
  3092 
  3093 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3094 adverse effect of Isabelle flooding interactive front-ends (notably
  3095 ProofGeneral / XEmacs).
  3096 
  3097 
  3098 
  3099 New in Isabelle2007 (November 2007)
  3100 -----------------------------------
  3101 
  3102 *** General ***
  3103 
  3104 * More uniform information about legacy features, notably a
  3105 warning/error of "Legacy feature: ...", depending on the state of the
  3106 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3107 legacy features will disappear eventually.
  3108 
  3109 * Theory syntax: the header format ``theory A = B + C:'' has been
  3110 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3111 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3112 
  3113 * Theory syntax: the old non-Isar theory file format has been
  3114 discontinued altogether.  Note that ML proof scripts may still be used
  3115 with Isar theories; migration is usually quite simple with the ML
  3116 function use_legacy_bindings.  INCOMPATIBILITY.
  3117 
  3118 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3119 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3120 quotes.
  3121 
  3122 * Theory loader: be more serious about observing the static theory
  3123 header specifications (including optional directories), but not the
  3124 accidental file locations of previously successful loads.  The strict
  3125 update policy of former update_thy is now already performed by
  3126 use_thy, so the former has been removed; use_thys updates several
  3127 theories simultaneously, just as 'imports' within a theory header
  3128 specification, but without merging the results.  Potential
  3129 INCOMPATIBILITY: may need to refine theory headers and commands
  3130 ROOT.ML which depend on load order.
  3131 
  3132 * Theory loader: optional support for content-based file
  3133 identification, instead of the traditional scheme of full physical
  3134 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3135 (cf. the system manual).  The new scheme allows to work with
  3136 non-finished theories in persistent session images, such that source
  3137 files may be moved later on without requiring reloads.
  3138 
  3139 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3140 file (with the same base name as the theory) are considered a legacy
  3141 feature, which will disappear eventually. Even now, the theory loader
  3142 no longer maintains dependencies on such files.
  3143 
  3144 * Syntax: the scope for resolving ambiguities via type-inference is
  3145 now limited to individual terms, instead of whole simultaneous
  3146 specifications as before. This greatly reduces the complexity of the
  3147 syntax module and improves flexibility by separating parsing and
  3148 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3149 'fixes' etc.) are required in rare situations.
  3150 
  3151 * Syntax: constants introduced by new-style packages ('definition',
  3152 'abbreviation' etc.) are passed through the syntax module in
  3153 ``authentic mode''. This means that associated mixfix annotations
  3154 really stick to such constants, independently of potential name space
  3155 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3156 trees are represented slightly differently, may need to adapt syntax
  3157 translations accordingly. Use CONST marker in 'translations' and
  3158 @{const_syntax} antiquotation in 'parse_translation' etc.
  3159 
  3160 * Legacy goal package: reduced interface to the bare minimum required
  3161 to keep existing proof scripts running.  Most other user-level
  3162 functions are now part of the OldGoals structure, which is *not* open
  3163 by default (consider isatool expandshort before open OldGoals).
  3164 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3165 these tend to cause confusion about the actual goal (!) context being
  3166 used here, which is not necessarily the same as the_context().
  3167 
  3168 * Command 'find_theorems': supports "*" wild-card in "name:"
  3169 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3170 support a specific search form (see ProofGeneral/CHANGES).
  3171 
  3172 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3173 by default, which means that "prems" (and also "fixed variables") are
  3174 suppressed from proof state output.  Note that the ProofGeneral
  3175 settings mechanism allows to change and save options persistently, but
  3176 older versions of Isabelle will fail to start up if a negative prems
  3177 limit is imposed.
  3178 
  3179 * Local theory targets may be specified by non-nested blocks of
  3180 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3181 contain definitions, theorems etc., including any derived mechanism
  3182 that has been implemented on top of these primitives.  This concept
  3183 generalizes the existing ``theorem (in ...)'' towards more versatility
  3184 and scalability.
  3185 
  3186 * Proof General interface: proper undo of final 'end' command;
  3187 discontinued Isabelle/classic mode (ML proof scripts).
  3188 
  3189 
  3190 *** Document preparation ***
  3191 
  3192 * Added antiquotation @{theory name} which prints the given name,
  3193 after checking that it refers to a valid ancestor theory in the
  3194 current context.
  3195 
  3196 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3197 check the given source text as ML type/structure, printing verbatim.
  3198 
  3199 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3200 "c args == rhs" given in the current context.  (Any number of
  3201 arguments may be given on the LHS.)
  3202 
  3203 
  3204 *** Pure ***
  3205 
  3206 * The 'class' package offers a combination of axclass and locale to
  3207 achieve Haskell-like type classes in Isabelle.  Definitions and
  3208 theorems within a class context produce both relative results (with
  3209 implicit parameters according to the locale context), and polymorphic
  3210 constants with qualified polymorphism (according to the class
  3211 context).  Within the body context of a 'class' target, a separate
  3212 syntax layer ("user space type system") takes care of converting
  3213 between global polymorphic consts and internal locale representation.
  3214 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3215 "isatool doc classes" provides a tutorial.
  3216 
  3217 * Generic code generator framework allows to generate executable
  3218 code for ML and Haskell (including Isabelle classes).  A short usage
  3219 sketch:
  3220 
  3221     internal compilation:
  3222         export_code <list of constants (term syntax)> in SML
  3223     writing SML code to a file:
  3224         export_code <list of constants (term syntax)> in SML <filename>
  3225     writing OCaml code to a file:
  3226         export_code <list of constants (term syntax)> in OCaml <filename>
  3227     writing Haskell code to a bunch of files:
  3228         export_code <list of constants (term syntax)> in Haskell <filename>
  3229 
  3230     evaluating closed propositions to True/False using code generation:
  3231         method ``eval''
  3232 
  3233 Reasonable default setup of framework in HOL.
  3234 
  3235 Theorem attributs for selecting and transforming function equations theorems:
  3236 
  3237     [code fun]:        select a theorem as function equation for a specific constant
  3238     [code fun del]:    deselect a theorem as function equation for a specific constant
  3239     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3240     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3241 
  3242 User-defined serializations (target in {SML, OCaml, Haskell}):
  3243 
  3244     code_const <and-list of constants (term syntax)>
  3245       {(target) <and-list of const target syntax>}+
  3246 
  3247     code_type <and-list of type constructors>
  3248       {(target) <and-list of type target syntax>}+
  3249 
  3250     code_instance <and-list of instances>
  3251       {(target)}+
  3252         where instance ::= <type constructor> :: <class>
  3253 
  3254     code_class <and_list of classes>
  3255       {(target) <and-list of class target syntax>}+
  3256         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3257 
  3258 code_instance and code_class only are effective to target Haskell.
  3259 
  3260 For example usage see src/HOL/ex/Codegenerator.thy and
  3261 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3262 generation from Isabelle/HOL theories is available via "isatool doc
  3263 codegen".
  3264 
  3265 * Code generator: consts in 'consts_code' Isar commands are now
  3266 referred to by usual term syntax (including optional type
  3267 annotations).
  3268 
  3269 * Command 'no_translations' removes translation rules from theory
  3270 syntax.
  3271 
  3272 * Overloaded definitions are now actually checked for acyclic
  3273 dependencies.  The overloading scheme is slightly more general than
  3274 that of Haskell98, although Isabelle does not demand an exact
  3275 correspondence to type class and instance declarations.
  3276 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3277 exotic versions of overloading -- at the discretion of the user!
  3278 
  3279 Polymorphic constants are represented via type arguments, i.e. the
  3280 instantiation that matches an instance against the most general
  3281 declaration given in the signature.  For example, with the declaration
  3282 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3283 as c(nat).  Overloading is essentially simultaneous structural
  3284 recursion over such type arguments.  Incomplete specification patterns
  3285 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3286 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3287 Command 'print_theory' outputs the normalized system of recursive
  3288 equations, see section "definitions".
  3289 
  3290 * Configuration options are maintained within the theory or proof
  3291 context (with name and type bool/int/string), providing a very simple
  3292 interface to a poor-man's version of general context data.  Tools may
  3293 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3294 these values using Config.get etc.  Users may change options via an
  3295 associated attribute of the same name.  This form of context
  3296 declaration works particularly well with commands 'declare' or
  3297 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3298 very easy to avoid global references, which would not observe Isar
  3299 toplevel undo/redo and fail to work with multithreading.
  3300 
  3301 Various global ML references of Pure and HOL have been turned into
  3302 configuration options:
  3303 
  3304   Unify.search_bound		unify_search_bound
  3305   Unify.trace_bound		unify_trace_bound
  3306   Unify.trace_simp		unify_trace_simp
  3307   Unify.trace_types		unify_trace_types
  3308   Simplifier.simp_depth_limit	simp_depth_limit
  3309   Blast.depth_limit		blast_depth_limit
  3310   DatatypeProp.dtK		datatype_distinctness_limit
  3311   fast_arith_neq_limit  	fast_arith_neq_limit
  3312   fast_arith_split_limit	fast_arith_split_limit
  3313 
  3314 * Named collections of theorems may be easily installed as context
  3315 data using the functor NamedThmsFun (see also
  3316 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3317 attributes; there is also a toplevel print command.  This facility is
  3318 just a common case of general context data, which is the preferred way
  3319 for anything more complex than just a list of facts in canonical
  3320 order.
  3321 
  3322 * Isar: command 'declaration' augments a local theory by generic
  3323 declaration functions written in ML.  This enables arbitrary content
  3324 being added to the context, depending on a morphism that tells the
  3325 difference of the original declaration context wrt. the application
  3326 context encountered later on.
  3327 
  3328 * Isar: proper interfaces for simplification procedures.  Command
  3329 'simproc_setup' declares named simprocs (with match patterns, and body
  3330 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3331 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3332 
  3333 * Isar: an extra pair of brackets around attribute declarations
  3334 abbreviates a theorem reference involving an internal dummy fact,
  3335 which will be ignored later --- only the effect of the attribute on
  3336 the background context will persist.  This form of in-place
  3337 declarations is particularly useful with commands like 'declare' and
  3338 'using', for example ``have A using [[simproc a]] by simp''.
  3339 
  3340 * Isar: method "assumption" (and implicit closing of subproofs) now
  3341 takes simple non-atomic goal assumptions into account: after applying
  3342 an assumption as a rule the resulting subgoals are solved by atomic
  3343 assumption steps.  This is particularly useful to finish 'obtain'
  3344 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3345 without referring to the original premise "!!x. P x ==> thesis" in the
  3346 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3347 more permissive.
  3348 
  3349 * Isar: implicit use of prems from the Isar proof context is
  3350 considered a legacy feature.  Common applications like ``have A .''
  3351 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3352 referencing facts explicitly here improves readability and
  3353 maintainability of proof texts.
  3354 
  3355 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3356 the obtained context from the course of reasoning!  For example:
  3357 
  3358   assume "EX x y. A x & B y"   -- "any previous fact"
  3359   then guess x and y by clarify
  3360 
  3361 This technique is potentially adventurous, depending on the facts and
  3362 proof tools being involved here.
  3363 
  3364 * Isar: known facts from the proof context may be specified as literal
  3365 propositions, using ASCII back-quote syntax.  This works wherever
  3366 named facts used to be allowed so far, in proof commands, proof
  3367 methods, attributes etc.  Literal facts are retrieved from the context
  3368 according to unification of type and term parameters.  For example,
  3369 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3370 theorems in the current context, then these are valid literal facts:
  3371 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3372 
  3373 There is also a proof method "fact" which does the same composition
  3374 for explicit goal states, e.g. the following proof texts coincide with
  3375 certain special cases of literal facts:
  3376 
  3377   have "A" by fact                 ==  note `A`
  3378   have "A ==> B" by fact           ==  note `A ==> B`
  3379   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3380   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3381 
  3382 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3383 outer syntax.  Thus symbolic identifiers may be used without
  3384 additional white space in declarations like this: ``assume *: A''.
  3385 
  3386 * Isar: 'print_facts' prints all local facts of the current context,
  3387 both named and unnamed ones.
  3388 
  3389 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3390 
  3391   def x == "t" and y == "u"
  3392 
  3393 * Isar: added command 'unfolding', which is structurally similar to
  3394 'using', but affects both the goal state and facts by unfolding given
  3395 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3396 'unfolded' attribute may be replaced by first-class proof text.
  3397 
  3398 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3399 and command 'unfolding' now all support object-level equalities
  3400 (potentially conditional).  The underlying notion of rewrite rule is
  3401 analogous to the 'rule_format' attribute, but *not* that of the
  3402 Simplifier (which is usually more generous).
  3403 
  3404 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3405 premises of a theorem by n. Useful in conjunction with drule.
  3406 
  3407 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3408 method expression within a sandbox consisting of the first N
  3409 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3410 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3411 simplifies all new goals that emerge from applying rule foo to the
  3412 originally first one.
  3413 
  3414 * Isar: schematic goals are no longer restricted to higher-order
  3415 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3416 expected.
  3417 
  3418 * Isar: the conclusion of a long theorem statement is now either
  3419 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3420 (essentially a disjunction of cases with local parameters and
  3421 assumptions).  The latter allows to express general elimination rules
  3422 adequately; in this notation common elimination rules look like this:
  3423 
  3424   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3425     assumes "EX x. P x"
  3426     obtains x where "P x"
  3427 
  3428   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3429     assumes "A & B"
  3430     obtains A and B
  3431 
  3432   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3433     assumes "A | B"
  3434     obtains
  3435       A
  3436     | B
  3437 
  3438 The subsequent classical rules even refer to the formal "thesis"
  3439 explicitly:
  3440 
  3441   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3442     obtains "~ thesis"
  3443 
  3444   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3445     obtains "thesis ==> something"
  3446 
  3447 The actual proof of an 'obtains' statement is analogous to that of the
  3448 Isar proof element 'obtain', only that there may be several cases.
  3449 Optional case names may be specified in parentheses; these will be
  3450 available both in the present proof and as annotations in the
  3451 resulting rule, for later use with the 'cases' method (cf. attribute
  3452 case_names).
  3453 
  3454 * Isar: the assumptions of a long theorem statement are available as
  3455 "assms" fact in the proof context.  This is more appropriate than the
  3456 (historical) "prems", which refers to all assumptions of the current
  3457 context, including those from the target locale, proof body etc.
  3458 
  3459 * Isar: 'print_statement' prints theorems from the current theory or
  3460 proof context in long statement form, according to the syntax of a
  3461 top-level lemma.
  3462 
  3463 * Isar: 'obtain' takes an optional case name for the local context
  3464 introduction rule (default "that").
  3465 
  3466 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3467 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3468 to occur.
  3469 
  3470 * Pure: syntax "CONST name" produces a fully internalized constant
  3471 according to the current context.  This is particularly useful for
  3472 syntax translations that should refer to internal constant
  3473 representations independently of name spaces.
  3474 
  3475 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3476 instead of "FOO ". This allows multiple binder declarations to coexist
  3477 in the same context.  INCOMPATIBILITY.
  3478 
  3479 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3480 primitive that also works in a locale context (both for constants and
  3481 fixed variables). Type declaration and internal syntactic representation
  3482 of given constants retrieved from the context. Likewise, the
  3483 'no_notation' command allows to remove given syntax annotations from the
  3484 current context.
  3485 
  3486 * Isar/locales: new derived specification elements 'axiomatization',
  3487 'definition', 'abbreviation', which support type-inference, admit
  3488 object-level specifications (equality, equivalence).  See also the
  3489 isar-ref manual.  Examples:
  3490 
  3491   axiomatization
  3492     eq  (infix "===" 50) where
  3493     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3494 
  3495   definition "f x y = x + y + 1"
  3496   definition g where "g x = f x x"
  3497 
  3498   abbreviation
  3499     neq  (infix "=!=" 50) where
  3500     "x =!= y == ~ (x === y)"
  3501 
  3502 These specifications may be also used in a locale context.  Then the
  3503 constants being introduced depend on certain fixed parameters, and the
  3504 constant name is qualified by the locale base name.  An internal
  3505 abbreviation takes care for convenient input and output, making the
  3506 parameters implicit and using the original short name.  See also
  3507 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3508 entities from a monomorphic theory.
  3509 
  3510 Presently, abbreviations are only available 'in' a target locale, but
  3511 not inherited by general import expressions.  Also note that
  3512 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3513 'translations' in common applications.  The "no_abbrevs" print mode
  3514 prevents folding of abbreviations in term output.
  3515 
  3516 Concrete syntax is attached to specified constants in internal form,
  3517 independently of name spaces.  The parse tree representation is
  3518 slightly different -- use 'notation' instead of raw 'syntax', and
  3519 'translations' with explicit "CONST" markup to accommodate this.
  3520 
  3521 * Pure/Isar: unified syntax for new-style specification mechanisms
  3522 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3523 full type inference and dummy patterns ("_").  For example:
  3524 
  3525   definition "K x _ = x"
  3526 
  3527   inductive conj for A B
  3528   where "A ==> B ==> conj A B"
  3529 
  3530 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3531 the current context.  Print mode "no_abbrevs" prevents inversion of
  3532 abbreviations on output.
  3533 
  3534 * Isar/locales: improved parameter handling: use of locales "var" and
  3535 "struct" no longer necessary; - parameter renamings are no longer
  3536 required to be injective.  For example, this allows to define
  3537 endomorphisms as locale endom = homom mult mult h.
  3538 
  3539 * Isar/locales: changed the way locales with predicates are defined.
  3540 Instead of accumulating the specification, the imported expression is
  3541 now an interpretation.  INCOMPATIBILITY: different normal form of
  3542 locale expressions.  In particular, in interpretations of locales with
  3543 predicates, goals repesenting already interpreted fragments are not
  3544 removed automatically.  Use methods `intro_locales' and
  3545 `unfold_locales'; see below.
  3546 
  3547 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3548 provide backward reasoning on locales predicates.  The methods are
  3549 aware of interpretations and discharge corresponding goals.
  3550 `intro_locales' is less aggressive then `unfold_locales' and does not
  3551 unfold predicates to assumptions.
  3552 
  3553 * Isar/locales: the order in which locale fragments are accumulated
  3554 has changed.  This enables to override declarations from fragments due
  3555 to interpretations -- for example, unwanted simp rules.
  3556 
  3557 * Isar/locales: interpretation in theories and proof contexts has been
  3558 extended.  One may now specify (and prove) equations, which are
  3559 unfolded in interpreted theorems.  This is useful for replacing
  3560 defined concepts (constants depending on locale parameters) by
  3561 concepts already existing in the target context.  Example:
  3562 
  3563   interpretation partial_order ["op <= :: [int, int] => bool"]
  3564     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3565 
  3566 Typically, the constant `partial_order.less' is created by a
  3567 definition specification element in the context of locale
  3568 partial_order.
  3569 
  3570 * Method "induct": improved internal context management to support
  3571 local fixes and defines on-the-fly. Thus explicit meta-level
  3572 connectives !!  and ==> are rarely required anymore in inductive goals
  3573 (using object-logic connectives for this purpose has been long
  3574 obsolete anyway). Common proof patterns are explained in
  3575 src/HOL/Induct/Common_Patterns.thy, see also
  3576 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3577 examples.
  3578 
  3579 * Method "induct": improved handling of simultaneous goals. Instead of
  3580 introducing object-level conjunction, the statement is now split into
  3581 several conclusions, while the corresponding symbolic cases are nested
  3582 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3583 see src/HOL/Induct/Common_Patterns.thy, for example.
  3584 
  3585 * Method "induct": mutual induction rules are now specified as a list
  3586 of rule sharing the same induction cases. HOL packages usually provide
  3587 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3588 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3589 mutual induction rules differently, i.e. like this:
  3590 
  3591   (induct rule: foo_bar.inducts)
  3592   (induct set: foo bar)
  3593   (induct pred: foo bar)
  3594   (induct type: foo bar)
  3595 
  3596 The ML function ProjectRule.projections turns old-style rules into the
  3597 new format.
  3598 
  3599 * Method "coinduct": dual of induction, see
  3600 src/HOL/Library/Coinductive_List.thy for various examples.
  3601 
  3602 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3603 considered a legacy feature.
  3604 
  3605 * Attribute "symmetric" produces result with standardized schematic
  3606 variables (index 0).  Potential INCOMPATIBILITY.
  3607 
  3608 * Simplifier: by default the simplifier trace only shows top level
  3609 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3610 default. Thus there is less danger of being flooded by the trace. The
  3611 trace indicates where parts have been suppressed.
  3612   
  3613 * Provers/classical: removed obsolete classical version of elim_format
  3614 attribute; classical elim/dest rules are now treated uniformly when
  3615 manipulating the claset.
  3616 
  3617 * Provers/classical: stricter checks to ensure that supplied intro,
  3618 dest and elim rules are well-formed; dest and elim rules must have at
  3619 least one premise.
  3620 
  3621 * Provers/classical: attributes dest/elim/intro take an optional
  3622 weight argument for the rule (just as the Pure versions).  Weights are
  3623 ignored by automated tools, but determine the search order of single
  3624 rule steps.
  3625 
  3626 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3627 where the body does not mention the bound variable.  Note that dummy
  3628 patterns implicitly depend on their context of bounds, which makes
  3629 "{_. _}" match any set comprehension as expected.  Potential
  3630 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3631 constant "_idtdummy" in the binding position.
  3632 
  3633 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3634 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3635 for example "A -> B" => "Pi A (%_. B)".
  3636 
  3637 * Pure: 'class_deps' command visualizes the subclass relation, using
  3638 the graph browser tool.
  3639 
  3640 * Pure: 'print_theory' now suppresses certain internal declarations by
  3641 default; use '!' option for full details.
  3642 
  3643 
  3644 *** HOL ***
  3645 
  3646 * Method "metis" proves goals by applying the Metis general-purpose
  3647 resolution prover (see also http://gilith.com/software/metis/).
  3648 Examples are in the directory MetisExamples.  WARNING: the
  3649 Isabelle/HOL-Metis integration does not yet work properly with
  3650 multi-threading.
  3651   
  3652 * Command 'sledgehammer' invokes external automatic theorem provers as
  3653 background processes.  It generates calls to the "metis" method if
  3654 successful. These can be pasted into the proof.  Users do not have to
  3655 wait for the automatic provers to return.  WARNING: does not really
  3656 work with multi-threading.
  3657 
  3658 * New "auto_quickcheck" feature tests outermost goal statements for
  3659 potential counter-examples.  Controlled by ML references
  3660 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3661 5000 milliseconds).  Fails silently if statements is outside of
  3662 executable fragment, or any other codgenerator problem occurs.
  3663 
  3664 * New constant "undefined" with axiom "undefined x = undefined".
  3665 
  3666 * Added class "HOL.eq", allowing for code generation with polymorphic
  3667 equality.
  3668 
  3669 * Some renaming of class constants due to canonical name prefixing in
  3670 the new 'class' package:
  3671 
  3672     HOL.abs ~> HOL.abs_class.abs
  3673     HOL.divide ~> HOL.divide_class.divide
  3674     0 ~> HOL.zero_class.zero
  3675     1 ~> HOL.one_class.one
  3676     op + ~> HOL.plus_class.plus
  3677     op - ~> HOL.minus_class.minus
  3678     uminus ~> HOL.minus_class.uminus
  3679     op * ~> HOL.times_class.times
  3680     op < ~> HOL.ord_class.less
  3681     op <= > HOL.ord_class.less_eq
  3682     Nat.power ~> Power.power_class.power
  3683     Nat.size ~> Nat.size_class.size
  3684     Numeral.number_of ~> Numeral.number_class.number_of
  3685     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3686     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3687     Orderings.min ~> Orderings.ord_class.min
  3688     Orderings.max ~> Orderings.ord_class.max
  3689     Divides.op div ~> Divides.div_class.div
  3690     Divides.op mod ~> Divides.div_class.mod
  3691     Divides.op dvd ~> Divides.div_class.dvd
  3692 
  3693 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3694 
  3695 a) User-defined constants using any of the names "plus", "minus",
  3696 "times", "less" or "less_eq". The standard syntax translations for
  3697 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3698 names.
  3699 
  3700 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3701 INCOMPATIBILITY: use more specific names.
  3702 
  3703 c) Permutative equations (e.g. "a + b = b + a")
  3704 Since the change of names also changes the order of terms, permutative
  3705 rewrite rules may get applied in a different order. Experience shows
  3706 that this is rarely the case (only two adaptions in the whole Isabelle
  3707 distribution).  INCOMPATIBILITY: rewrite proofs
  3708 
  3709 d) ML code directly refering to constant names
  3710 This in general only affects hand-written proof tactics, simprocs and
  3711 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3712 Consider using @{const_name} antiquotation.
  3713 
  3714 * New class "default" with associated constant "default".
  3715 
  3716 * Function "sgn" is now overloaded and available on int, real, complex
  3717 (and other numeric types), using class "sgn".  Two possible defs of
  3718 sgn are given as equational assumptions in the classes sgn_if and
  3719 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3720 INCOMPATIBILITY.
  3721 
  3722 * Locale "partial_order" now unified with class "order" (cf. theory
  3723 Orderings), added parameter "less".  INCOMPATIBILITY.
  3724 
  3725 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3726 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3727 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3728 
  3729 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3730 changed order of proof goals in instance proofs.
  3731 
  3732 * The transitivity reasoner for partial and linear orders is set up
  3733 for classes "order" and "linorder".  Instances of the reasoner are available
  3734 in all contexts importing or interpreting the corresponding locales.
  3735 Method "order" invokes the reasoner separately; the reasoner
  3736 is also integrated with the Simplifier as a solver.  Diagnostic
  3737 command 'print_orders' shows the available instances of the reasoner
  3738 in the current context.
  3739 
  3740 * Localized monotonicity predicate in theory "Orderings"; integrated
  3741 lemmas max_of_mono and min_of_mono with this predicate.
  3742 INCOMPATIBILITY.
  3743 
  3744 * Formulation of theorem "dense" changed slightly due to integration
  3745 with new class dense_linear_order.
  3746 
  3747 * Uniform lattice theory development in HOL.
  3748 
  3749     constants "meet" and "join" now named "inf" and "sup"
  3750     constant "Meet" now named "Inf"
  3751 
  3752     classes "meet_semilorder" and "join_semilorder" now named
  3753       "lower_semilattice" and "upper_semilattice"
  3754     class "lorder" now named "lattice"
  3755     class "comp_lat" now named "complete_lattice"
  3756 
  3757     Instantiation of lattice classes allows explicit definitions
  3758     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3759 
  3760   INCOMPATIBILITY.  Theorem renames:
  3761 
  3762     meet_left_le            ~> inf_le1
  3763     meet_right_le           ~> inf_le2
  3764     join_left_le            ~> sup_ge1
  3765     join_right_le           ~> sup_ge2
  3766     meet_join_le            ~> inf_sup_ord
  3767     le_meetI                ~> le_infI
  3768     join_leI                ~> le_supI
  3769     le_meet                 ~> le_inf_iff
  3770     le_join                 ~> ge_sup_conv
  3771     meet_idempotent         ~> inf_idem
  3772     join_idempotent         ~> sup_idem
  3773     meet_comm               ~> inf_commute
  3774     join_comm               ~> sup_commute
  3775     meet_leI1               ~> le_infI1
  3776     meet_leI2               ~> le_infI2
  3777     le_joinI1               ~> le_supI1
  3778     le_joinI2               ~> le_supI2
  3779     meet_assoc              ~> inf_assoc
  3780     join_assoc              ~> sup_assoc
  3781     meet_left_comm          ~> inf_left_commute
  3782     meet_left_idempotent    ~> inf_left_idem
  3783     join_left_comm          ~> sup_left_commute
  3784     join_left_idempotent    ~> sup_left_idem
  3785     meet_aci                ~> inf_aci
  3786     join_aci                ~> sup_aci
  3787     le_def_meet             ~> le_iff_inf
  3788     le_def_join             ~> le_iff_sup
  3789     join_absorp2            ~> sup_absorb2
  3790     join_absorp1            ~> sup_absorb1
  3791     meet_absorp1            ~> inf_absorb1
  3792     meet_absorp2            ~> inf_absorb2
  3793     meet_join_absorp        ~> inf_sup_absorb
  3794     join_meet_absorp        ~> sup_inf_absorb
  3795     distrib_join_le         ~> distrib_sup_le
  3796     distrib_meet_le         ~> distrib_inf_le
  3797 
  3798     add_meet_distrib_left   ~> add_inf_distrib_left
  3799     add_join_distrib_left   ~> add_sup_distrib_left
  3800     is_join_neg_meet        ~> is_join_neg_inf
  3801     is_meet_neg_join        ~> is_meet_neg_sup
  3802     add_meet_distrib_right  ~> add_inf_distrib_right
  3803     add_join_distrib_right  ~> add_sup_distrib_right
  3804     add_meet_join_distribs  ~> add_sup_inf_distribs
  3805     join_eq_neg_meet        ~> sup_eq_neg_inf
  3806     meet_eq_neg_join        ~> inf_eq_neg_sup
  3807     add_eq_meet_join        ~> add_eq_inf_sup
  3808     meet_0_imp_0            ~> inf_0_imp_0
  3809     join_0_imp_0            ~> sup_0_imp_0
  3810     meet_0_eq_0             ~> inf_0_eq_0
  3811     join_0_eq_0             ~> sup_0_eq_0
  3812     neg_meet_eq_join        ~> neg_inf_eq_sup
  3813     neg_join_eq_meet        ~> neg_sup_eq_inf
  3814     join_eq_if              ~> sup_eq_if
  3815 
  3816     mono_meet               ~> mono_inf
  3817     mono_join               ~> mono_sup
  3818     meet_bool_eq            ~> inf_bool_eq
  3819     join_bool_eq            ~> sup_bool_eq
  3820     meet_fun_eq             ~> inf_fun_eq
  3821     join_fun_eq             ~> sup_fun_eq
  3822     meet_set_eq             ~> inf_set_eq
  3823     join_set_eq             ~> sup_set_eq
  3824     meet1_iff               ~> inf1_iff
  3825     meet2_iff               ~> inf2_iff
  3826     meet1I                  ~> inf1I
  3827     meet2I                  ~> inf2I
  3828     meet1D1                 ~> inf1D1
  3829     meet2D1                 ~> inf2D1
  3830     meet1D2                 ~> inf1D2
  3831     meet2D2                 ~> inf2D2
  3832     meet1E                  ~> inf1E
  3833     meet2E                  ~> inf2E
  3834     join1_iff               ~> sup1_iff
  3835     join2_iff               ~> sup2_iff
  3836     join1I1                 ~> sup1I1
  3837     join2I1                 ~> sup2I1
  3838     join1I1                 ~> sup1I1
  3839     join2I2                 ~> sup1I2
  3840     join1CI                 ~> sup1CI
  3841     join2CI                 ~> sup2CI
  3842     join1E                  ~> sup1E
  3843     join2E                  ~> sup2E
  3844 
  3845     is_meet_Meet            ~> is_meet_Inf
  3846     Meet_bool_def           ~> Inf_bool_def
  3847     Meet_fun_def            ~> Inf_fun_def
  3848     Meet_greatest           ~> Inf_greatest
  3849     Meet_lower              ~> Inf_lower
  3850     Meet_set_def            ~> Inf_set_def
  3851 
  3852     Sup_def                 ~> Sup_Inf
  3853     Sup_bool_eq             ~> Sup_bool_def
  3854     Sup_fun_eq              ~> Sup_fun_def
  3855     Sup_set_eq              ~> Sup_set_def
  3856 
  3857     listsp_meetI            ~> listsp_infI
  3858     listsp_meet_eq          ~> listsp_inf_eq
  3859 
  3860     meet_min                ~> inf_min
  3861     join_max                ~> sup_max
  3862 
  3863 * Added syntactic class "size"; overloaded constant "size" now has
  3864 type "'a::size ==> bool"
  3865 
  3866 * Internal reorganisation of `size' of datatypes: size theorems
  3867 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3868 simplification rules by default!); theorems "prod.size" now named
  3869 "*.size".
  3870 
  3871 * Class "div" now inherits from class "times" rather than "type".
  3872 INCOMPATIBILITY.
  3873 
  3874 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3875 Linorder etc.  have disappeared; operations defined in terms of
  3876 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3877 
  3878 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3879 
  3880 * HOL-Word: New extensive library and type for generic, fixed size
  3881 machine words, with arithemtic, bit-wise, shifting and rotating
  3882 operations, reflection into int, nat, and bool lists, automation for
  3883 linear arithmetic (by automatic reflection into nat or int), including
  3884 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3885 arithmetic type classes, supporting automatic simplification of
  3886 numerals on all operations.
  3887 
  3888 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3889 
  3890 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3891 
  3892 * Code generator library theories:
  3893   - Code_Integer represents HOL integers by big integer literals in target
  3894     languages.
  3895   - Code_Char represents HOL characters by character literals in target
  3896     languages.
  3897   - Code_Char_chr like Code_Char, but also offers treatment of character
  3898     codes; includes Code_Integer.
  3899   - Executable_Set allows to generate code for finite sets using lists.
  3900   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3901     denominator).
  3902   - Executable_Real implements a subset of real numbers, namly those
  3903     representable by rational numbers.
  3904   - Efficient_Nat implements natural numbers by integers, which in general will
  3905     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3906     includes Code_Integer.
  3907   - Code_Index provides an additional datatype index which is mapped to
  3908     target-language built-in integers.
  3909   - Code_Message provides an additional datatype message_string which is isomorphic to
  3910     strings; messages are mapped to target-language strings.
  3911 
  3912 * New package for inductive predicates
  3913 
  3914   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3915 
  3916     inductive
  3917       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3918       for z_1 :: U_1 and ... and z_n :: U_m
  3919     where
  3920       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3921     | ...
  3922 
  3923   with full support for type-inference, rather than
  3924 
  3925     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3926 
  3927     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3928     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3929 
  3930     inductive "s z_1 ... z_m"
  3931     intros
  3932       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3933       ...
  3934 
  3935   For backward compatibility, there is a wrapper allowing inductive
  3936   sets to be defined with the new package via
  3937 
  3938     inductive_set
  3939       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3940       for z_1 :: U_1 and ... and z_n :: U_m
  3941     where
  3942       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3943     | ...
  3944 
  3945   or
  3946 
  3947     inductive_set
  3948       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3949       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3950       for z_1 :: U_1 and ... and z_n :: U_m
  3951     where
  3952       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3953     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3954     | ...
  3955 
  3956   if the additional syntax "p ..." is required.
  3957 
  3958   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3959   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3960 
  3961   INCOMPATIBILITIES:
  3962 
  3963   - Since declaration and definition of inductive sets or predicates
  3964     is no longer separated, abbreviations involving the newly
  3965     introduced sets or predicates must be specified together with the
  3966     introduction rules after the 'where' keyword (see above), rather
  3967     than before the actual inductive definition.
  3968 
  3969   - The variables in induction and elimination rules are now
  3970     quantified in the order of their occurrence in the introduction
  3971     rules, rather than in alphabetical order. Since this may break
  3972     some proofs, these proofs either have to be repaired, e.g. by
  3973     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3974     statements of the form
  3975 
  3976       case (rule_i a_i_1 ... a_i_{k_i})
  3977 
  3978     or the old order of quantification has to be restored by explicitly adding
  3979     meta-level quantifiers in the introduction rules, i.e.
  3980 
  3981       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3982 
  3983   - The format of the elimination rules is now
  3984 
  3985       p z_1 ... z_m x_1 ... x_n ==>
  3986         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3987         ==> ... ==> P
  3988 
  3989     for predicates and
  3990 
  3991       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3992         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3993         ==> ... ==> P
  3994 
  3995     for sets rather than
  3996 
  3997       x : s z_1 ... z_m ==>
  3998         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3999         ==> ... ==> P
  4000 
  4001     This may require terms in goals to be expanded to n-tuples
  4002     (e.g. using case_tac or simplification with the split_paired_all
  4003     rule) before the above elimination rule is applicable.
  4004 
  4005   - The elimination or case analysis rules for (mutually) inductive
  4006     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4007     list of rules "p_1_..._p_k.elims" is no longer available.
  4008 
  4009 * New package "function"/"fun" for general recursive functions,
  4010 supporting mutual and nested recursion, definitions in local contexts,
  4011 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4012 for small examples, and the separate tutorial on the function
  4013 package. The old recdef "package" is still available as before, but
  4014 users are encouraged to use the new package.
  4015 
  4016 * Method "lexicographic_order" automatically synthesizes termination
  4017 relations as lexicographic combinations of size measures. 
  4018 
  4019 * Case-expressions allow arbitrary constructor-patterns (including
  4020 "_") and take their order into account, like in functional
  4021 programming.  Internally, this is translated into nested
  4022 case-expressions; missing cases are added and mapped to the predefined
  4023 constant "undefined". In complicated cases printing may no longer show
  4024 the original input but the internal form. Lambda-abstractions allow
  4025 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4026 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4027 variable.
  4028 
  4029 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4030 is an abbreviation for "of_nat :: nat => int". The simplification
  4031 rules for "of_nat" have been changed to work like "int" did
  4032 previously.  Potential INCOMPATIBILITY:
  4033   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4034   - of_nat_diff and of_nat_mult are no longer default simp rules
  4035 
  4036 * Method "algebra" solves polynomial equations over (semi)rings using
  4037 Groebner bases. The (semi)ring structure is defined by locales and the
  4038 tool setup depends on that generic context. Installing the method for
  4039 a specific type involves instantiating the locale and possibly adding
  4040 declarations for computation on the coefficients.  The method is
  4041 already instantiated for natural numbers and for the axiomatic class
  4042 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4043 CALCULEMUS 2007 for the general principles underlying this
  4044 architecture of context-aware proof-tools.
  4045 
  4046 * Method "ferrack" implements quantifier elimination over
  4047 special-purpose dense linear orders using locales (analogous to
  4048 "algebra"). The method is already installed for class
  4049 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4050 rat, etc.
  4051 
  4052 * Former constant "List.op @" now named "List.append".  Use ML
  4053 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4054 circumvent possible incompatibilities when working on ML level.
  4055 
  4056 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4057 
  4058 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4059 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4060 
  4061 * New syntax for Haskell-like list comprehension (input only), eg.
  4062 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4063 
  4064 * The special syntax for function "filter" has changed from [x :
  4065 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4066 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4067 
  4068 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4069 defined on nat only, as an abbreviation for [a..<Suc b]
  4070 INCOMPATIBILITY.
  4071 
  4072 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4073 
  4074 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4075 
  4076 * New lemma collection field_simps (an extension of ring_simps) for
  4077 manipulating (in)equations involving division. Multiplies with all
  4078 denominators that can be proved to be non-zero (in equations) or
  4079 positive/negative (in inequations).
  4080 
  4081 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4082 have been improved and renamed to ring_simps, group_simps and
  4083 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4084 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4085 
  4086 * Theory Library/Commutative_Ring: switched from recdef to function
  4087 package; constants add, mul, pow now curried.  Infix syntax for
  4088 algebraic operations.
  4089 
  4090 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4091 INCOMPATIBILITY.
  4092 
  4093 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4094 INCOMPATIBILITY.
  4095 
  4096 * HOL/records: generalised field-update to take a function on the
  4097 field rather than the new value: r(|A := x|) is translated to A_update
  4098 (K x) r The K-combinator that is internally used is called K_record.
  4099 INCOMPATIBILITY: Usage of the plain update functions has to be
  4100 adapted.
  4101  
  4102 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4103 * x = 0, which are required for a semiring.  Richer structures do not
  4104 inherit from semiring_0 anymore, because this property is a theorem
  4105 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4106 there is more to prove, but this is mostly trivial.
  4107 
  4108 * Class "recpower" is generalized to arbitrary monoids, not just
  4109 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4110 commutativity or semiring properties additionally.
  4111 
  4112 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4113 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4114 better use 'abbreviation'.
  4115 
  4116 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4117 
  4118 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4119 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4120 significant changes for setting up numeral syntax for types:
  4121   - New constants Numeral.pred and Numeral.succ instead
  4122       of former Numeral.bin_pred and Numeral.bin_succ.
  4123   - Use integer operations instead of bin_add, bin_mult and so on.
  4124   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4125   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4126 
  4127 See src/HOL/Integ/IntArith.thy for an example setup.
  4128 
  4129 * Command 'normal_form' computes the normal form of a term that may
  4130 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4131 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4132 heavy-duty computations because the functions are compiled to ML
  4133 first.  Correspondingly, a method "normalization" is provided.  See
  4134 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4135 
  4136 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4137 25 like -->); output depends on the "iff" print_mode, the default is
  4138 "A = B" (with priority 50).
  4139 
  4140 * Relations less (<) and less_eq (<=) are also available on type bool.
  4141 Modified syntax to disallow nesting without explicit parentheses,
  4142 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4143 INCOMPATIBILITY.
  4144 
  4145 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4146 
  4147 * Relation composition operator "op O" now has precedence 75 and binds
  4148 stronger than union and intersection. INCOMPATIBILITY.
  4149 
  4150 * The old set interval syntax "{m..n(}" (and relatives) has been
  4151 removed.  Use "{m..<n}" (and relatives) instead.
  4152 
  4153 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4154 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4155 ``declare [[simproc del: neq]]''.
  4156 
  4157 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4158 True/False.
  4159 
  4160 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4161 
  4162 * Theorem setsum_mult renamed to setsum_right_distrib.
  4163 
  4164 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4165 ``rule'' method.
  4166 
  4167 * Reimplemented methods "sat" and "satx", with several improvements:
  4168 goals no longer need to be stated as "<prems> ==> False", equivalences
  4169 (i.e. "=" on type bool) are handled, variable names of the form
  4170 "lit_<n>" are no longer reserved, significant speedup.
  4171 
  4172 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4173 zChaff is still supported as well.
  4174 
  4175 * 'inductive' and 'datatype': provide projections of mutual rules,
  4176 bundled as foo_bar.inducts;
  4177 
  4178 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4179 Library.
  4180 
  4181 * Library: moved theory Accessible_Part to main HOL.
  4182 
  4183 * Library: added theory Coinductive_List of potentially infinite lists
  4184 as greatest fixed-point.
  4185 
  4186 * Library: added theory AssocList which implements (finite) maps as
  4187 association lists.
  4188 
  4189 * Method "evaluation" solves goals (i.e. a boolean expression)
  4190 efficiently by compiling it to ML.  The goal is "proved" (via an
  4191 oracle) if it evaluates to True.
  4192 
  4193 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4194 also when invoked by the simplifier.  This results in the Simplifier
  4195 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4196 Configuration option fast_arith_split_limit=0 recovers the old
  4197 behavior.
  4198 
  4199 * Support for hex (0x20) and binary (0b1001) numerals.
  4200 
  4201 * New method: reify eqs (t), where eqs are equations for an
  4202 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4203 parameter, computes a term s::'b and a list xs::'a list and proves the
  4204 theorem I xs s = t. This is also known as reification or quoting. The
  4205 resulting theorem is applied to the subgoal to substitute t with I xs
  4206 s.  If t is omitted, the subgoal itself is reified.
  4207 
  4208 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4209 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4210 where f is supposed to be a computable function (in the sense of code
  4211 generattion). The method uses reify to compute s and xs as above then
  4212 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4213 r and finally gets the theorem t = r, which is again applied to the
  4214 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4215 
  4216 * Reflection: Automatic reification now handels binding, an example is
  4217 available in src/HOL/ex/ReflectionEx.thy
  4218 
  4219 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4220 command 'statespace' that is similar to 'record', but introduces an
  4221 abstract specification based on the locale infrastructure instead of
  4222 HOL types.  This leads to extra flexibility in composing state spaces,
  4223 in particular multiple inheritance and renaming of components.
  4224 
  4225 
  4226 *** HOL-Complex ***
  4227 
  4228 * Hyperreal: Functions root and sqrt are now defined on negative real
  4229 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4230 Nonnegativity side conditions have been removed from many lemmas, so
  4231 that more subgoals may now be solved by simplification; potential
  4232 INCOMPATIBILITY.
  4233 
  4234 * Real: new type classes formalize real normed vector spaces and
  4235 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4236 and norm :: 'a => real.
  4237 
  4238 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4239 reals into other types. The overloaded constant Reals :: 'a set is now
  4240 defined as range of_real; potential INCOMPATIBILITY.
  4241 
  4242 * Real: proper support for ML code generation, including 'quickcheck'.
  4243 Reals are implemented as arbitrary precision rationals.
  4244 
  4245 * Hyperreal: Several constants that previously worked only for the
  4246 reals have been generalized, so they now work over arbitrary vector
  4247 spaces. Type annotations may need to be added in some cases; potential
  4248 INCOMPATIBILITY.
  4249 
  4250   Infinitesimal  :: ('a::real_normed_vector) star set
  4251   HFinite        :: ('a::real_normed_vector) star set
  4252   HInfinite      :: ('a::real_normed_vector) star set
  4253   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4254   monad          :: ('a::real_normed_vector) star => 'a star set
  4255   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4256   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4257   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4258   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4259   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4260   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4261   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4262   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4263   sgn            :: 'a::real_normed_vector => 'a
  4264   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4265 
  4266 * Complex: Some complex-specific constants are now abbreviations for
  4267 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4268 hnorm.  Other constants have been entirely removed in favor of the
  4269 polymorphic versions (INCOMPATIBILITY):
  4270 
  4271   approx        <-- capprox
  4272   HFinite       <-- CFinite
  4273   HInfinite     <-- CInfinite
  4274   Infinitesimal <-- CInfinitesimal
  4275   monad         <-- cmonad
  4276   galaxy        <-- cgalaxy
  4277   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4278   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4279   (ns)deriv     <-- (ns)cderiv
  4280 
  4281 
  4282 *** HOL-Algebra ***
  4283 
  4284 * Formalisation of ideals and the quotient construction over rings.
  4285 
  4286 * Order and lattice theory no longer based on records.
  4287 INCOMPATIBILITY.
  4288 
  4289 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4290 greatest_closed.  INCOMPATIBILITY.
  4291 
  4292 * Method algebra is now set up via an attribute.  For examples see
  4293 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4294 of algebraic structures.
  4295 
  4296 * Renamed theory CRing to Ring.
  4297 
  4298 
  4299 *** HOL-Nominal ***
  4300 
  4301 * Substantial, yet incomplete support for nominal datatypes (binding
  4302 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4303 src/HOL/Nominal/Examples.  Prospective users should consult
  4304 http://isabelle.in.tum.de/nominal/
  4305 
  4306 
  4307 *** ML ***
  4308 
  4309 * ML basics: just one true type int, which coincides with IntInf.int
  4310 (even on SML/NJ).
  4311 
  4312 * ML within Isar: antiquotations allow to embed statically-checked
  4313 formal entities in the source, referring to the context available at
  4314 compile-time.  For example:
  4315 
  4316 ML {* @{sort "{zero,one}"} *}
  4317 ML {* @{typ "'a => 'b"} *}
  4318 ML {* @{term "%x. x"} *}
  4319 ML {* @{prop "x == y"} *}
  4320 ML {* @{ctyp "'a => 'b"} *}
  4321 ML {* @{cterm "%x. x"} *}
  4322 ML {* @{cprop "x == y"} *}
  4323 ML {* @{thm asm_rl} *}
  4324 ML {* @{thms asm_rl} *}
  4325 ML {* @{type_name c} *}
  4326 ML {* @{type_syntax c} *}
  4327 ML {* @{const_name c} *}
  4328 ML {* @{const_syntax c} *}
  4329 ML {* @{context} *}
  4330 ML {* @{theory} *}
  4331 ML {* @{theory Pure} *}
  4332 ML {* @{theory_ref} *}
  4333 ML {* @{theory_ref Pure} *}
  4334 ML {* @{simpset} *}
  4335 ML {* @{claset} *}
  4336 ML {* @{clasimpset} *}
  4337 
  4338 The same works for sources being ``used'' within an Isar context.
  4339 
  4340 * ML in Isar: improved error reporting; extra verbosity with
  4341 ML_Context.trace enabled.
  4342 
  4343 * Pure/General/table.ML: the join operations now works via exceptions
  4344 DUP/SAME instead of type option. This is simpler in simple cases, and
  4345 admits slightly more efficient complex applications.
  4346 
  4347 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4348 use Context.generic instead of just theory.
  4349 
  4350 * Pure: datatype Context.generic joins theory/Proof.context and
  4351 provides some facilities for code that works in either kind of
  4352 context, notably GenericDataFun for uniform theory and proof data.
  4353 
  4354 * Pure: simplified internal attribute type, which is now always
  4355 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4356 local (Proof.context) attributes have been discontinued, while
  4357 minimizing code duplication. Thm.rule_attribute and
  4358 Thm.declaration_attribute build canonical attributes; see also structure
  4359 Context for further operations on Context.generic, notably
  4360 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4361 declarations and definitions.
  4362 
  4363 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4364 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4365 init only required for impure data. INCOMPATIBILITY: empty really need
  4366 to be empty (no dependencies on theory content!)
  4367 
  4368 * Pure/kernel: consts certification ignores sort constraints given in
  4369 signature declarations. (This information is not relevant to the
  4370 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4371 potential INCOMPATIBILITY.
  4372 
  4373 * Pure: axiomatic type classes are now purely definitional, with
  4374 explicit proofs of class axioms and super class relations performed
  4375 internally. See Pure/axclass.ML for the main internal interfaces --
  4376 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4377 AxClass.axiomatize_class/classrel/arity supersede
  4378 Sign.add_classes/classrel/arities.
  4379 
  4380 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4381 global/local versions on theory vs. Proof.context have been
  4382 discontinued; Attrib.syntax and Method.syntax have been adapted
  4383 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4384 attributes, methods, etc.
  4385 
  4386 * Pure: several functions of signature "... -> theory -> theory * ..."
  4387 have been reoriented to "... -> theory -> ... * theory" in order to
  4388 allow natural usage in combination with the ||>, ||>>, |-> and
  4389 fold_map combinators.
  4390 
  4391 * Pure: official theorem names (closed derivations) and additional
  4392 comments (tags) are now strictly separate.  Name hints -- which are
  4393 maintained as tags -- may be attached any time without affecting the
  4394 derivation.
  4395 
  4396 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4397 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4398 achieve the old behaviour.
  4399 
  4400 * Pure: the "Goal" constant is now called "prop", supporting a
  4401 slightly more general idea of ``protecting'' meta-level rule
  4402 statements.
  4403 
  4404 * Pure: Logic.(un)varify only works in a global context, which is now
  4405 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4406 Logic.legacy_(un)varify as temporary workaround.
  4407 
  4408 * Pure: structure Name provides scalable operations for generating
  4409 internal variable names, notably Name.variants etc.  This replaces
  4410 some popular functions from term.ML:
  4411 
  4412   Term.variant		->  Name.variant
  4413   Term.variantlist	->  Name.variant_list
  4414   Term.invent_names	->  Name.invent_list
  4415 
  4416 Note that low-level renaming rarely occurs in new code -- operations
  4417 from structure Variable are used instead (see below).
  4418 
  4419 * Pure: structure Variable provides fundamental operations for proper
  4420 treatment of fixed/schematic variables in a context.  For example,
  4421 Variable.import introduces fixes for schematics of given facts and
  4422 Variable.export reverses the effect (up to renaming) -- this replaces
  4423 various freeze_thaw operations.
  4424 
  4425 * Pure: structure Goal provides simple interfaces for
  4426 init/conclude/finish and tactical prove operations (replacing former
  4427 Tactic.prove).  Goal.prove is the canonical way to prove results
  4428 within a given context; Goal.prove_global is a degraded version for
  4429 theory level goals, including a global Drule.standard.  Note that
  4430 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4431 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4432 in a locale context).
  4433 
  4434 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4435 and type checking (Syntax.check_term etc.), with common combinations
  4436 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4437 which are considered legacy and await removal.
  4438 
  4439 * Pure/Syntax: generic interfaces for type unchecking
  4440 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4441 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4442 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4443 available for convenience, but refer to the very same operations using
  4444 a mere theory instead of a full context.
  4445 
  4446 * Isar: simplified treatment of user-level errors, using exception
  4447 ERROR of string uniformly.  Function error now merely raises ERROR,
  4448 without any side effect on output channels.  The Isar toplevel takes
  4449 care of proper display of ERROR exceptions.  ML code may use plain
  4450 handle/can/try; cat_error may be used to concatenate errors like this:
  4451 
  4452   ... handle ERROR msg => cat_error msg "..."
  4453 
  4454 Toplevel ML code (run directly or through the Isar toplevel) may be
  4455 embedded into the Isar toplevel with exception display/debug like
  4456 this:
  4457 
  4458   Isar.toplevel (fn () => ...)
  4459 
  4460 INCOMPATIBILITY, removed special transform_error facilities, removed
  4461 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4462 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4463 -- use plain ERROR instead.
  4464 
  4465 * Isar: theory setup now has type (theory -> theory), instead of a
  4466 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4467 
  4468 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4469 ProofContext.debug/verbose flags.
  4470 
  4471 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4472 theory before entering a proof state.  Transactions now always see a
  4473 quasi-functional intermediate checkpoint, both in interactive and
  4474 batch mode.
  4475 
  4476 * Isar: simplified interfaces for outer syntax.  Renamed
  4477 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4478 OuterSyntax.add_parsers -- this functionality is now included in
  4479 OuterSyntax.command etc.  INCOMPATIBILITY.
  4480 
  4481 * Simplifier: the simpset of a running simplification process now
  4482 contains a proof context (cf. Simplifier.the_context), which is the
  4483 very context that the initial simpset has been retrieved from (by
  4484 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4485 (solver, looper etc.) may depend on arbitrary proof data.
  4486 
  4487 * Simplifier.inherit_context inherits the proof context (plus the
  4488 local bounds) of the current simplification process; any simproc
  4489 etc. that calls the Simplifier recursively should do this!  Removed
  4490 former Simplifier.inherit_bounds, which is already included here --
  4491 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4492 specify an explicit context using Simplifier.context/theory_context.
  4493 
  4494 * Simplifier/Classical Reasoner: more abstract interfaces
  4495 change_simpset/claset for modifying the simpset/claset reference of a
  4496 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4497 INCOMPATIBILITY.
  4498 
  4499 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4500 "Trueprop" etc.
  4501 
  4502 
  4503 *** System ***
  4504 
  4505 * settings: the default heap location within ISABELLE_HOME_USER now
  4506 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4507 Isabelle installations.
  4508 
  4509 * isabelle-process: option -S (secure mode) disables some critical
  4510 operations, notably runtime compilation and evaluation of ML source
  4511 code.
  4512 
  4513 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4514 
  4515 * Support for parallel execution, using native multicore support of
  4516 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4517 independent theories, according to the given theory header
  4518 specifications. The maximum number of worker threads is specified via
  4519 usedir option -M or the "max-threads" setting in Proof General. A
  4520 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4521 to 6 on a 8-core machine.  User-code needs to observe certain
  4522 guidelines for thread-safe programming, see appendix A in the Isar
  4523 Implementation manual.
  4524 
  4525 
  4526 
  4527 New in Isabelle2005 (October 2005)
  4528 ----------------------------------
  4529 
  4530 *** General ***
  4531 
  4532 * Theory headers: the new header syntax for Isar theories is
  4533 
  4534   theory <name>
  4535   imports <theory1> ... <theoryN>
  4536   uses <file1> ... <fileM>
  4537   begin
  4538 
  4539 where the 'uses' part is optional.  The previous syntax
  4540 
  4541   theory <name> = <theory1> + ... + <theoryN>:
  4542 
  4543 will disappear in the next release.  Use isatool fixheaders to convert
  4544 existing theory files.  Note that there is no change in ancient
  4545 non-Isar theories now, but these will disappear soon.
  4546 
  4547 * Theory loader: parent theories can now also be referred to via
  4548 relative and absolute paths.
  4549 
  4550 * Command 'find_theorems' searches for a list of criteria instead of a
  4551 list of constants. Known criteria are: intro, elim, dest, name:string,
  4552 simp:term, and any term. Criteria can be preceded by '-' to select
  4553 theorems that do not match. Intro, elim, dest select theorems that
  4554 match the current goal, name:s selects theorems whose fully qualified
  4555 name contain s, and simp:term selects all simplification rules whose
  4556 lhs match term.  Any other term is interpreted as pattern and selects
  4557 all theorems matching the pattern. Available in ProofGeneral under
  4558 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4559 
  4560   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4561 
  4562 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4563 matching the current goal as introduction rule and not having "HOL."
  4564 in their name (i.e. not being defined in theory HOL).
  4565 
  4566 * Command 'thms_containing' has been discontinued in favour of
  4567 'find_theorems'; INCOMPATIBILITY.
  4568 
  4569 * Communication with Proof General is now 8bit clean, which means that
  4570 Unicode text in UTF-8 encoding may be used within theory texts (both
  4571 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4572 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4573 
  4574   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4575   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4576 
  4577 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4578 Classical Reasoner.  Typical big applications run around 2 times
  4579 faster.
  4580 
  4581 
  4582 *** Document preparation ***
  4583 
  4584 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4585 of raw sources.  Only those symbols that do not require additional
  4586 LaTeX packages (depending on comments in isabellesym.sty) are
  4587 displayed properly, everything else is left verbatim.  isatool display
  4588 and isatool print are used as front ends (these are subject to the
  4589 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4590 
  4591 * Command tags control specific markup of certain regions of text,
  4592 notably folding and hiding.  Predefined tags include "theory" (for
  4593 theory begin and end), "proof" for proof commands, and "ML" for
  4594 commands involving ML code; the additional tags "visible" and
  4595 "invisible" are unused by default.  Users may give explicit tag
  4596 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4597 interpretation of tags is determined by the LaTeX job during document
  4598 preparation: see option -V of isatool usedir, or options -n and -t of
  4599 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4600 \isadroptag.
  4601 
  4602 Several document versions may be produced at the same time via isatool
  4603 usedir (the generated index.html will link all of them).  Typical
  4604 specifications include ''-V document=theory,proof,ML'' to present
  4605 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4606 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4607 these parts without any formal replacement text.  The Isabelle site
  4608 default settings produce ''document'' and ''outline'' versions as
  4609 specified above.
  4610 
  4611 * Several new antiquotations:
  4612 
  4613   @{term_type term} prints a term with its type annotated;
  4614 
  4615   @{typeof term} prints the type of a term;
  4616 
  4617   @{const const} is the same as @{term const}, but checks that the
  4618   argument is a known logical constant;
  4619 
  4620   @{term_style style term} and @{thm_style style thm} print a term or
  4621   theorem applying a "style" to it
  4622 
  4623   @{ML text}
  4624 
  4625 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4626 definitions, equations, inequations etc., 'concl' printing only the
  4627 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4628 to print the specified premise.  TermStyle.add_style provides an ML
  4629 interface for introducing further styles.  See also the "LaTeX Sugar"
  4630 document practical applications.  The ML antiquotation prints
  4631 type-checked ML expressions verbatim.
  4632 
  4633 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4634 and 'text' support optional locale specification '(in loc)', which
  4635 specifies the default context for interpreting antiquotations.  For
  4636 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4637 
  4638 * Option 'locale=NAME' of antiquotations specifies an alternative
  4639 context interpreting the subsequent argument.  For example: @{thm
  4640 [locale=lattice] inf_assoc}.
  4641 
  4642 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4643 a proof context.
  4644 
  4645 * Proper output of antiquotations for theory commands involving a
  4646 proof context (such as 'locale' or 'theorem (in loc) ...').
  4647 
  4648 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4649 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4650 
  4651 * isatool usedir: new option -C (default true) controls whether option
  4652 -D should include a copy of the original document directory; -C false
  4653 prevents unwanted effects such as copying of administrative CVS data.
  4654 
  4655 
  4656 *** Pure ***
  4657 
  4658 * Considerably improved version of 'constdefs' command.  Now performs
  4659 automatic type-inference of declared constants; additional support for
  4660 local structure declarations (cf. locales and HOL records), see also
  4661 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4662 sequential dependencies of definitions within a single 'constdefs'
  4663 section; moreover, the declared name needs to be an identifier.  If
  4664 all fails, consider to fall back on 'consts' and 'defs' separately.
  4665 
  4666 * Improved indexed syntax and implicit structures.  First of all,
  4667 indexed syntax provides a notational device for subscripted
  4668 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4669 expressions.  Secondly, in a local context with structure
  4670 declarations, number indexes \<^sub>n or the empty index (default
  4671 number 1) refer to a certain fixed variable implicitly; option
  4672 show_structs controls printing of implicit structures.  Typical
  4673 applications of these concepts involve record types and locales.
  4674 
  4675 * New command 'no_syntax' removes grammar declarations (and
  4676 translations) resulting from the given syntax specification, which is
  4677 interpreted in the same manner as for the 'syntax' command.
  4678 
  4679 * 'Advanced' translation functions (parse_translation etc.) may depend
  4680 on the signature of the theory context being presently used for
  4681 parsing/printing, see also isar-ref manual.
  4682 
  4683 * Improved 'oracle' command provides a type-safe interface to turn an
  4684 ML expression of type theory -> T -> term into a primitive rule of
  4685 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4686 is already included here); see also FOL/ex/IffExample.thy;
  4687 INCOMPATIBILITY.
  4688 
  4689 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4690 before); "cI" is no longer bound, use "c.intro" instead.
  4691 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4692 axclasses vs. locales.
  4693 
  4694 * Improved internal renaming of symbolic identifiers -- attach primes
  4695 instead of base 26 numbers.
  4696 
  4697 * New flag show_question_marks controls printing of leading question
  4698 marks in schematic variable names.
  4699 
  4700 * In schematic variable names, *any* symbol following \<^isub> or
  4701 \<^isup> is now treated as part of the base name.  For example, the
  4702 following works without printing of awkward ".0" indexes:
  4703 
  4704   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4705     by simp
  4706 
  4707 * Inner syntax includes (*(*nested*) comments*).
  4708 
  4709 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4710 annotations as "(00...)".
  4711 
  4712 * Clear separation of logical types and nonterminals, where the latter
  4713 may only occur in 'syntax' specifications or type abbreviations.
  4714 Before that distinction was only partially implemented via type class
  4715 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4716 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4717 exotic syntax specifications may require further adaption
  4718 (e.g. Cube/Cube.thy).
  4719 
  4720 * Removed obsolete type class "logic", use the top sort {} instead.
  4721 Note that non-logical types should be declared as 'nonterminals'
  4722 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4723 specifications.
  4724 
  4725 * Attributes 'induct' and 'cases': type or set names may now be
  4726 locally fixed variables as well.
  4727 
  4728 * Simplifier: can now control the depth to which conditional rewriting
  4729 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4730 Limit.
  4731 
  4732 * Simplifier: simplification procedures may now take the current
  4733 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4734 interface), which is very useful for calling the Simplifier
  4735 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4736 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4737 low-level mk_simproc no longer applies Logic.varify internally, to
  4738 allow for use in a context of fixed variables.
  4739 
  4740 * thin_tac now works even if the assumption being deleted contains !!
  4741 or ==>.  More generally, erule now works even if the major premise of
  4742 the elimination rule contains !! or ==>.
  4743 
  4744 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4745 
  4746 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4747 from Pure, which contains all common declarations already.  Both
  4748 theories are defined via plain Isabelle/Isar .thy files.
  4749 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4750 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4751 use isatool fixcpure to adapt your theory and ML sources.
  4752 
  4753 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4754 selections of theorems in named facts via index ranges.
  4755 
  4756 * 'print_theorems': in theory mode, really print the difference
  4757 wrt. the last state (works for interactive theory development only),
  4758 in proof mode print all local facts (cf. 'print_facts');
  4759 
  4760 * 'hide': option '(open)' hides only base names.
  4761 
  4762 * More efficient treatment of intermediate checkpoints in interactive
  4763 theory development.
  4764 
  4765 * Code generator is now invoked via code_module (incremental code
  4766 generation) and code_library (modular code generation, ML structures
  4767 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4768 must be quoted when used as identifiers.
  4769 
  4770 * New 'value' command for reading, evaluating and printing terms using
  4771 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4772 quoted when used as identifier.
  4773 
  4774 
  4775 *** Locales ***
  4776 
  4777 * New commands for the interpretation of locale expressions in
  4778 theories (1), locales (2) and proof contexts (3).  These generate
  4779 proof obligations from the expression specification.  After the
  4780 obligations have been discharged, theorems of the expression are added
  4781 to the theory, target locale or proof context.  The synopsis of the
  4782 commands is a follows:
  4783 
  4784   (1) interpretation expr inst
  4785   (2) interpretation target < expr
  4786   (3) interpret expr inst
  4787 
  4788 Interpretation in theories and proof contexts require a parameter
  4789 instantiation of terms from the current context.  This is applied to
  4790 specifications and theorems of the interpreted expression.
  4791 Interpretation in locales only permits parameter renaming through the
  4792 locale expression.  Interpretation is smart in that interpretations
  4793 that are active already do not occur in proof obligations, neither are
  4794 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4795 inspect active interpretations of a particular locale.  For details,
  4796 see the Isar Reference manual.  Examples can be found in
  4797 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4798 
  4799 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4800 'interpret' instead.
  4801 
  4802 * New context element 'constrains' for adding type constraints to
  4803 parameters.
  4804 
  4805 * Context expressions: renaming of parameters with syntax
  4806 redeclaration.
  4807 
  4808 * Locale declaration: 'includes' disallowed.
  4809 
  4810 * Proper static binding of attribute syntax -- i.e. types / terms /
  4811 facts mentioned as arguments are always those of the locale definition
  4812 context, independently of the context of later invocations.  Moreover,
  4813 locale operations (renaming and type / term instantiation) are applied
  4814 to attribute arguments as expected.
  4815 
  4816 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4817 actual attributes; rare situations may require Attrib.attribute to
  4818 embed those attributes into Attrib.src that lack concrete syntax.
  4819 Attribute implementations need to cooperate properly with the static
  4820 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4821 Attrib.XXX_thm etc. already do the right thing without further
  4822 intervention.  Only unusual applications -- such as "where" or "of"
  4823 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4824 on the context and the facts involved -- may have to assign parsed
  4825 values to argument tokens explicitly.
  4826 
  4827 * Changed parameter management in theorem generation for long goal
  4828 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4829 theorem statement in rare situations.
  4830 
  4831 * Locale inspection command 'print_locale' omits notes elements.  Use
  4832 'print_locale!' to have them included in the output.
  4833 
  4834 
  4835 *** Provers ***
  4836 
  4837 * Provers/hypsubst.ML: improved version of the subst method, for
  4838 single-step rewriting: it now works in bound variable contexts. New is
  4839 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4840 rewrite a different subterm than the original subst method, which is
  4841 still available as 'simplesubst'.
  4842 
  4843 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4844 and quasi orders.
  4845 
  4846 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4847 reflexive-transitive closure of relations.
  4848 
  4849 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4850 limit (previously hard-coded with a value of 20) user-definable.
  4851 
  4852 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4853 is peformed already.  Object-logics merely need to finish their
  4854 initial simpset configuration as before.  INCOMPATIBILITY.
  4855 
  4856 
  4857 *** HOL ***
  4858 
  4859 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4860 
  4861   syntax (epsilon)
  4862     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4863 
  4864 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4865 and x-symbol; use option '-m epsilon' to get it actually printed.
  4866 Moreover, the mathematically important symbolic identifier \<epsilon>
  4867 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4868 
  4869 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4870 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4871 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4872 support corresponding Isar calculations.
  4873 
  4874 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4875 instead of ":".
  4876 
  4877 * theory SetInterval: changed the syntax for open intervals:
  4878 
  4879   Old       New
  4880   {..n(}    {..<n}
  4881   {)n..}    {n<..}
  4882   {m..n(}   {m..<n}
  4883   {)m..n}   {m<..n}
  4884   {)m..n(}  {m<..<n}
  4885 
  4886 The old syntax is still supported but will disappear in the next
  4887 release.  For conversion use the following Emacs search and replace
  4888 patterns (these are not perfect but work quite well):
  4889 
  4890   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4891   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4892 
  4893 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4894 equalities in commutative rings; method 'algebra' provides a generic
  4895 interface.
  4896 
  4897 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4898 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4899 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4900 be a tuple pattern.
  4901 
  4902 Some new syntax forms are available:
  4903 
  4904   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4905   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4906   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4907   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4908 
  4909 The latter form "\<Sum>x < k. e" used to be based on a separate
  4910 function "Summation", which has been discontinued.
  4911 
  4912 * theory Finite_Set: in structured induction proofs, the insert case
  4913 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4914 (insert F x)'.
  4915 
  4916 * The 'refute' command has been extended to support a much larger
  4917 fragment of HOL, including axiomatic type classes, constdefs and
  4918 typedefs, inductive datatypes and recursion.
  4919 
  4920 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4921 Requires zChaff with proof generation to be installed.  See
  4922 HOL/ex/SAT_Examples.thy for examples.
  4923 
  4924 * Datatype induction via method 'induct' now preserves the name of the
  4925 induction variable. For example, when proving P(xs::'a list) by
  4926 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4927 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4928 in unstructured proof scripts.
  4929 
  4930 * Reworked implementation of records.  Improved scalability for
  4931 records with many fields, avoiding performance problems for type
  4932 inference. Records are no longer composed of nested field types, but
  4933 of nested extension types. Therefore the record type only grows linear
  4934 in the number of extensions and not in the number of fields.  The
  4935 top-level (users) view on records is preserved.  Potential
  4936 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4937 old record representation. The type generated for a record is called
  4938 <record_name>_ext_type.
  4939 
  4940 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4941 proofs triggered by a record definition or a simproc (if
  4942 quick_and_dirty is enabled).  Definitions of large records can take
  4943 quite long.
  4944 
  4945 New simproc record_upd_simproc for simplification of multiple record
  4946 updates enabled by default.  Moreover, trivial updates are also
  4947 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4948 occasionally, since simplification is more powerful by default.
  4949 
  4950 * typedef: proper support for polymorphic sets, which contain extra
  4951 type-variables in the term.
  4952 
  4953 * Simplifier: automatically reasons about transitivity chains
  4954 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4955 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4956 old proofs break occasionally as simplification may now solve more
  4957 goals than previously.
  4958 
  4959 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4960 present.  Works for all partial orders (class "order"), in particular
  4961 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4962 just like y <= x.
  4963 
  4964 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4965 bound variable or a constant then the let is unfolded.  Otherwise
  4966 first a is simplified to b, and then f b is simplified to g. If
  4967 possible we abstract b from g arriving at "let x = b in h x",
  4968 otherwise we unfold the let and arrive at g.  The simproc can be
  4969 enabled/disabled by the reference use_let_simproc.  Potential
  4970 INCOMPATIBILITY since simplification is more powerful by default.
  4971 
  4972 * Classical reasoning: the meson method now accepts theorems as arguments.
  4973 
  4974 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4975 jobs to provide advice on the provability of subgoals.
  4976 
  4977 * Theory OrderedGroup and Ring_and_Field: various additions and
  4978 improvements to faciliate calculations involving equalities and
  4979 inequalities.
  4980 
  4981 The following theorems have been eliminated or modified
  4982 (INCOMPATIBILITY):
  4983 
  4984   abs_eq             now named abs_of_nonneg
  4985   abs_of_ge_0        now named abs_of_nonneg
  4986   abs_minus_eq       now named abs_of_nonpos
  4987   imp_abs_id         now named abs_of_nonneg
  4988   imp_abs_neg_id     now named abs_of_nonpos
  4989   mult_pos           now named mult_pos_pos
  4990   mult_pos_le        now named mult_nonneg_nonneg
  4991   mult_pos_neg_le    now named mult_nonneg_nonpos
  4992   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4993   mult_neg           now named mult_neg_neg
  4994   mult_neg_le        now named mult_nonpos_nonpos
  4995 
  4996 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4997      
  4998      zero_le_square
  4999      not_square_less_zero 
  5000 
  5001   The following lemmas have been deleted from Real/RealPow:
  5002   
  5003      realpow_zero_zero
  5004      realpow_two
  5005      realpow_less
  5006      zero_le_power
  5007      realpow_two_le
  5008      abs_realpow_two
  5009      realpow_two_abs     
  5010 
  5011 * Theory Parity: added rules for simplifying exponents.
  5012 
  5013 * Theory List:
  5014 
  5015 The following theorems have been eliminated or modified
  5016 (INCOMPATIBILITY):
  5017 
  5018   list_all_Nil       now named list_all.simps(1)
  5019   list_all_Cons      now named list_all.simps(2)
  5020   list_all_conv      now named list_all_iff
  5021   set_mem_eq         now named mem_iff
  5022 
  5023 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5024 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5025 
  5026 
  5027 *** HOL-Complex ***
  5028 
  5029 * Theory RealDef: better support for embedding natural numbers and
  5030 integers in the reals.
  5031 
  5032 The following theorems have been eliminated or modified
  5033 (INCOMPATIBILITY):
  5034 
  5035   exp_ge_add_one_self  now requires no hypotheses
  5036   real_of_int_add      reversed direction of equality (use [symmetric])
  5037   real_of_int_minus    reversed direction of equality (use [symmetric])
  5038   real_of_int_diff     reversed direction of equality (use [symmetric])
  5039   real_of_int_mult     reversed direction of equality (use [symmetric])
  5040 
  5041 * Theory RComplete: expanded support for floor and ceiling functions.
  5042 
  5043 * Theory Ln is new, with properties of the natural logarithm
  5044 
  5045 * Hyperreal: There is a new type constructor "star" for making
  5046 nonstandard types.  The old type names are now type synonyms:
  5047 
  5048   hypreal = real star
  5049   hypnat = nat star
  5050   hcomplex = complex star
  5051 
  5052 * Hyperreal: Many groups of similarly-defined constants have been
  5053 replaced by polymorphic versions (INCOMPATIBILITY):
  5054 
  5055   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5056 
  5057   starset      <-- starsetNat, starsetC
  5058   *s*          <-- *sNat*, *sc*
  5059   starset_n    <-- starsetNat_n, starsetC_n
  5060   *sn*         <-- *sNatn*, *scn*
  5061   InternalSets <-- InternalNatSets, InternalCSets
  5062 
  5063   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5064   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5065   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5066   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5067   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5068 
  5069 * Hyperreal: Many type-specific theorems have been removed in favor of
  5070 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5071 
  5072   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5073   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5074   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5075   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5076   right_minus <-- hypreal_add_minus
  5077   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5078   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5079   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5080   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5081   mult_1_right <-- hcomplex_mult_one_right
  5082   mult_zero_left <-- hcomplex_mult_zero_left
  5083   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5084   right_distrib <-- hypnat_add_mult_distrib2
  5085   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5086   right_inverse <-- hypreal_mult_inverse
  5087   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5088   order_refl <-- {hypreal,hypnat}_le_refl
  5089   order_trans <-- {hypreal,hypnat}_le_trans
  5090   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5091   order_less_le <-- {hypreal,hypnat}_less_le
  5092   linorder_linear <-- {hypreal,hypnat}_le_linear
  5093   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5094   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5095   add_nonneg_nonneg <-- hypreal_le_add_order
  5096 
  5097 * Hyperreal: Separate theorems having to do with type-specific
  5098 versions of constants have been merged into theorems that apply to the
  5099 new polymorphic constants (INCOMPATIBILITY):
  5100 
  5101   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5102   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5103   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5104   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5105   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5106   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5107   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5108   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5109   STAR_diff <-- {STAR,STARC}_diff
  5110   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5111     STARC_hcomplex_of_complex}_image_subset
  5112   starset_n_Un <-- starset{Nat,C}_n_Un
  5113   starset_n_Int <-- starset{Nat,C}_n_Int
  5114   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5115   starset_n_diff <-- starset{Nat,C}_n_diff
  5116   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5117   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5118   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5119   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5120   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5121   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5122   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5123   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5124   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5125   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5126   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5127   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5128   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5129   starfun_diff <-- starfun{C,RC,CR}_diff
  5130   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5131   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5132   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5133   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5134   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5135   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5136   starfun_Id <-- starfunC_Id
  5137   starfun_approx <-- starfun{Nat,CR}_approx
  5138   starfun_capprox <-- starfun{C,RC}_capprox
  5139   starfun_abs <-- starfunNat_rabs
  5140   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5141   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5142   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5143   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5144   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5145   starfun_add_approx <-- starfunCR_add_approx
  5146   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5147   starfun_divide <-- starfun{C,CR,RC}_divide
  5148   starfun_n <-- starfun{Nat,C}_n
  5149   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5150   starfun_n_add <-- starfun{Nat,C}_n_add
  5151   starfun_n_add_minus <-- starfunNat_n_add_minus
  5152   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5153   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5154   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5155 
  5156   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5157   star_n_minus <-- {hypreal,hcomplex}_minus
  5158   star_n_diff <-- {hypreal,hcomplex}_diff
  5159   star_n_mult <-- {hypreal,hcomplex}_mult
  5160   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5161   star_n_le <-- {hypreal,hypnat}_le
  5162   star_n_less <-- {hypreal,hypnat}_less
  5163   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5164   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5165   star_n_abs <-- hypreal_hrabs
  5166   star_n_divide <-- hcomplex_divide
  5167 
  5168   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5169   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5170   star_of_diff <-- hypreal_of_real_diff
  5171   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5172   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5173   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5174   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5175   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5176   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5177   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5178   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5179   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5180   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5181   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5182   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5183   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5184   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5185   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5186   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5187   star_of_power <-- hypreal_of_real_power
  5188   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5189 
  5190 * Hyperreal: new method "transfer" that implements the transfer
  5191 principle of nonstandard analysis. With a subgoal that mentions
  5192 nonstandard types like "'a star", the command "apply transfer"
  5193 replaces it with an equivalent one that mentions only standard types.
  5194 To be successful, all free variables must have standard types; non-
  5195 standard variables must have explicit universal quantifiers.
  5196 
  5197 * Hyperreal: A theory of Taylor series.
  5198 
  5199 
  5200 *** HOLCF ***
  5201 
  5202 * Discontinued special version of 'constdefs' (which used to support
  5203 continuous functions) in favor of the general Pure one with full
  5204 type-inference.
  5205 
  5206 * New simplification procedure for solving continuity conditions; it
  5207 is much faster on terms with many nested lambda abstractions (cubic
  5208 instead of exponential time).
  5209 
  5210 * New syntax for domain package: selector names are now optional.
  5211 Parentheses should be omitted unless argument is lazy, for example:
  5212 
  5213   domain 'a stream = cons "'a" (lazy "'a stream")
  5214 
  5215 * New command 'fixrec' for defining recursive functions with pattern
  5216 matching; defining multiple functions with mutual recursion is also
  5217 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5218 sinr, or any data constructor defined by the domain package. The given
  5219 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5220 syntax and examples.
  5221 
  5222 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5223 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5224 but the proof obligation additionally includes an admissibility
  5225 requirement. The packages generate instances of class cpo or pcpo,
  5226 with continuity and strictness theorems for Rep and Abs.
  5227 
  5228 * HOLCF: Many theorems have been renamed according to a more standard naming
  5229 scheme (INCOMPATIBILITY):
  5230 
  5231   foo_inject:  "foo$x = foo$y ==> x = y"
  5232   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5233   foo_less:    "(foo$x << foo$y) = (x << y)"
  5234   foo_strict:  "foo$UU = UU"
  5235   foo_defined: "... ==> foo$x ~= UU"
  5236   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5237 
  5238 
  5239 *** ZF ***
  5240 
  5241 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5242 including the First Isomorphism Theorem (on quotienting by the kernel
  5243 of a homomorphism).
  5244 
  5245 * ZF/Simplifier: install second copy of type solver that actually
  5246 makes use of TC rules declared to Isar proof contexts (or locales);
  5247 the old version is still required for ML proof scripts.
  5248 
  5249 
  5250 *** Cube ***
  5251 
  5252 * Converted to Isar theory format; use locales instead of axiomatic
  5253 theories.
  5254 
  5255 
  5256 *** ML ***
  5257 
  5258 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5259 for ||>, ||>>, |>>,
  5260 
  5261 * Pure/library.ML no longer defines its own option datatype, but uses
  5262 that of the SML basis, which has constructors NONE and SOME instead of
  5263 None and Some, as well as exception Option.Option instead of OPTION.
  5264 The functions the, if_none, is_some, is_none have been adapted
  5265 accordingly, while Option.map replaces apsome.
  5266 
  5267 * Pure/library.ML: the exception LIST has been given up in favour of
  5268 the standard exceptions Empty and Subscript, as well as
  5269 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5270 superceded by the standard hd and tl functions etc.
  5271 
  5272 A number of basic list functions are no longer exported to the ML
  5273 toplevel, as they are variants of predefined functions.  The following
  5274 suggests how one can translate existing code:
  5275 
  5276     rev_append xs ys = List.revAppend (xs, ys)
  5277     nth_elem (i, xs) = List.nth (xs, i)
  5278     last_elem xs = List.last xs
  5279     flat xss = List.concat xss
  5280     seq fs = List.app fs
  5281     partition P xs = List.partition P xs
  5282     mapfilter f xs = List.mapPartial f xs
  5283 
  5284 * Pure/library.ML: several combinators for linear functional
  5285 transformations, notably reverse application and composition:
  5286 
  5287   x |> f                f #> g
  5288   (x, y) |-> f          f #-> g
  5289 
  5290 * Pure/library.ML: introduced/changed precedence of infix operators:
  5291 
  5292   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5293   infix 2 ?;
  5294   infix 3 o oo ooo oooo;
  5295   infix 4 ~~ upto downto;
  5296 
  5297 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5298 infix operators.
  5299 
  5300 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5301 fold_map support linear functional transformations and nesting.  For
  5302 example:
  5303 
  5304   fold f [x1, ..., xN] y =
  5305     y |> f x1 |> ... |> f xN
  5306 
  5307   (fold o fold) f [xs1, ..., xsN] y =
  5308     y |> fold f xs1 |> ... |> fold f xsN
  5309 
  5310   fold f [x1, ..., xN] =
  5311     f x1 #> ... #> f xN
  5312 
  5313   (fold o fold) f [xs1, ..., xsN] =
  5314     fold f xs1 #> ... #> fold f xsN
  5315 
  5316 * Pure/library.ML: the following selectors on type 'a option are
  5317 available:
  5318 
  5319   the:               'a option -> 'a  (*partial*)
  5320   these:             'a option -> 'a  where 'a = 'b list
  5321   the_default: 'a -> 'a option -> 'a
  5322   the_list:          'a option -> 'a list
  5323 
  5324 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5325 basic operations for association lists, following natural argument
  5326 order; moreover the explicit equality predicate passed here avoids
  5327 potentially expensive polymorphic runtime equality checks.
  5328 The old functions may be expressed as follows:
  5329 
  5330   assoc = uncurry (AList.lookup (op =))
  5331   assocs = these oo AList.lookup (op =)
  5332   overwrite = uncurry (AList.update (op =)) o swap
  5333 
  5334 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5335 
  5336   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5337   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5338 
  5339 replacing make_keylist and keyfilter (occassionally used)
  5340 Naive rewrites:
  5341 
  5342   make_keylist = AList.make
  5343   keyfilter = AList.find (op =)
  5344 
  5345 * eq_fst and eq_snd now take explicit equality parameter, thus
  5346   avoiding eqtypes. Naive rewrites:
  5347 
  5348     eq_fst = eq_fst (op =)
  5349     eq_snd = eq_snd (op =)
  5350 
  5351 * Removed deprecated apl and apr (rarely used).
  5352   Naive rewrites:
  5353 
  5354     apl (n, op) =>>= curry op n
  5355     apr (op, m) =>>= fn n => op (n, m)
  5356 
  5357 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5358 provides a reasonably efficient light-weight implementation of sets as
  5359 lists.
  5360 
  5361 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5362 few new operations; existing lookup and update are now curried to
  5363 follow natural argument order (for use with fold etc.);
  5364 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5365 
  5366 * Pure/General: output via the Isabelle channels of
  5367 writeln/warning/error etc. is now passed through Output.output, with a
  5368 hook for arbitrary transformations depending on the print_mode
  5369 (cf. Output.add_mode -- the first active mode that provides a output
  5370 function wins).  Already formatted output may be embedded into further
  5371 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5372 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5373 accommodate easy composition of diagnostic messages etc.  Programmers
  5374 rarely need to care about Output.output or Output.raw at all, with
  5375 some notable exceptions: Output.output is required when bypassing the
  5376 standard channels (writeln etc.), or in token translations to produce
  5377 properly formatted results; Output.raw is required when capturing
  5378 already output material that will eventually be presented to the user
  5379 a second time.  For the default print mode, both Output.output and
  5380 Output.raw have no effect.
  5381 
  5382 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5383 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5384 cumulative results are displayed at the end of a batch session.
  5385 
  5386 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5387 replaced by File.platform_path and File.shell_path (with appropriate
  5388 hooks).  This provides a clean interface for unusual systems where the
  5389 internal and external process view of file names are different.
  5390 
  5391 * Pure: more efficient orders for basic syntactic entities: added
  5392 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5393 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5394 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5395 orders now -- potential INCOMPATIBILITY for code that depends on a
  5396 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5397 Library.sort_strings on result).
  5398 
  5399 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5400 fold_types traverse types/terms from left to right, observing natural
  5401 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5402 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5403 
  5404 * Pure: name spaces have been refined, with significant changes of the
  5405 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5406 to extern(_table).  The plain name entry path is superceded by a
  5407 general 'naming' context, which also includes the 'policy' to produce
  5408 a fully qualified name and external accesses of a fully qualified
  5409 name; NameSpace.extend is superceded by context dependent
  5410 Sign.declare_name.  Several theory and proof context operations modify
  5411 the naming context.  Especially note Theory.restore_naming and
  5412 ProofContext.restore_naming to get back to a sane state; note that
  5413 Theory.add_path is no longer sufficient to recover from
  5414 Theory.absolute_path in particular.
  5415 
  5416 * Pure: new flags short_names (default false) and unique_names
  5417 (default true) for controlling output of qualified names.  If
  5418 short_names is set, names are printed unqualified.  If unique_names is
  5419 reset, the name prefix is reduced to the minimum required to achieve
  5420 the original result when interning again, even if there is an overlap
  5421 with earlier declarations.
  5422 
  5423 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5424 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5425 (useful for printing error messages).  INCOMPATIBILITY.
  5426 
  5427 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5428 Theory.theory are now identified, referring to the universal
  5429 Context.theory (see Pure/context.ML).  Actual signature and theory
  5430 content is managed as theory data.  The old code and interfaces were
  5431 spread over many files and structures; the new arrangement introduces
  5432 considerable INCOMPATIBILITY to gain more clarity:
  5433 
  5434   Context -- theory management operations (name, identity, inclusion,
  5435     parents, ancestors, merge, etc.), plus generic theory data;
  5436 
  5437   Sign -- logical signature and syntax operations (declaring consts,
  5438     types, etc.), plus certify/read for common entities;
  5439 
  5440   Theory -- logical theory operations (stating axioms, definitions,
  5441     oracles), plus a copy of logical signature operations (consts,
  5442     types, etc.); also a few basic management operations (Theory.copy,
  5443     Theory.merge, etc.)
  5444 
  5445 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5446 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5447 for convenience -- they merely return the theory.
  5448 
  5449 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5450 
  5451 * Pure: the Isar proof context type is already defined early in Pure
  5452 as Context.proof (note that ProofContext.context and Proof.context are
  5453 aliases, where the latter is the preferred name).  This enables other
  5454 Isabelle components to refer to that type even before Isar is present.
  5455 
  5456 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5457 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5458 any of these kinds.  For example, Sign.intern typeK is now
  5459 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5460 Theory.hide_types.  Also note that former
  5461 Theory.hide_classes/types/consts are now
  5462 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5463 internalize their arguments!  INCOMPATIBILITY.
  5464 
  5465 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5466 datatype thmref (with constructors Name and NameSelection) instead of
  5467 plain string -- INCOMPATIBILITY;
  5468 
  5469 * Pure: cases produced by proof methods specify options, where NONE
  5470 means to remove case bindings -- INCOMPATIBILITY in
  5471 (RAW_)METHOD_CASES.
  5472 
  5473 * Pure: the following operations retrieve axioms or theorems from a
  5474 theory node or theory hierarchy, respectively:
  5475 
  5476   Theory.axioms_of: theory -> (string * term) list
  5477   Theory.all_axioms_of: theory -> (string * term) list
  5478   PureThy.thms_of: theory -> (string * thm) list
  5479   PureThy.all_thms_of: theory -> (string * thm) list
  5480 
  5481 * Pure: print_tac now outputs the goal through the trace channel.
  5482 
  5483 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5484 Reference Toplevel.debug (default false) controls detailed printing
  5485 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5486 controls execution profiling -- set to 1 for time and 2 for space
  5487 (both increase the runtime).
  5488 
  5489 * Isar session: The initial use of ROOT.ML is now always timed,
  5490 i.e. the log will show the actual process times, in contrast to the
  5491 elapsed wall-clock time that the outer shell wrapper produces.
  5492 
  5493 * Simplifier: improved handling of bound variables (nameless
  5494 representation, avoid allocating new strings).  Simprocs that invoke
  5495 the Simplifier recursively should use Simplifier.inherit_bounds to
  5496 avoid local name clashes.  Failure to do so produces warnings
  5497 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5498 for further details.
  5499 
  5500 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5501 bindings for all theorems stored within a given theory; this may help
  5502 in porting non-Isar theories to Isar ones, while keeping ML proof
  5503 scripts for the time being.
  5504 
  5505 * ML operator HTML.with_charset specifies the charset begin used for
  5506 generated HTML files.  For example:
  5507 
  5508   HTML.with_charset "utf-8" use_thy "Hebrew";
  5509   HTML.with_charset "utf-8" use_thy "Chinese";
  5510 
  5511 
  5512 *** System ***
  5513 
  5514 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5515 isabelle, isatool etc.).
  5516 
  5517 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5518 isatool doc, isatool mkdir, display_drafts etc.).
  5519 
  5520 * isatool usedir: option -f allows specification of the ML file to be
  5521 used by Isabelle; default is ROOT.ML.
  5522 
  5523 * New isatool version outputs the version identifier of the Isabelle
  5524 distribution being used.
  5525 
  5526 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5527 (containing Boolean satisfiability problems) into Isabelle/HOL
  5528 theories.
  5529 
  5530 
  5531 
  5532 New in Isabelle2004 (April 2004)
  5533 --------------------------------
  5534 
  5535 *** General ***
  5536 
  5537 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5538   Replaces linorder.ML.
  5539 
  5540 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5541   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5542   (\<a>...\<z>), are now considered normal letters, and can therefore
  5543   be used anywhere where an ASCII letter (a...zA...Z) has until
  5544   now. COMPATIBILITY: This obviously changes the parsing of some
  5545   terms, especially where a symbol has been used as a binder, say
  5546   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5547   as an identifier.  Fix it by inserting a space around former
  5548   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5549   existing theory and ML files.
  5550 
  5551 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5552 
  5553 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5554   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5555   a normal (but invisible) letter. For multiple letter subscripts repeat
  5556   \<^isub> like this: x\<^isub>1\<^isub>2.
  5557 
  5558 * Pure: There are now sub-/superscripts that can span more than one
  5559   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5560   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5561   superscript. The new control characters are not identifier parts.
  5562 
  5563 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5564   content of "..." to the latex file instead of \isacntrl... . The "..."
  5565   may consist of any printable characters excluding the end bracket >.
  5566 
  5567 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5568   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5569   declare constants "final", which prevents their being given a definition
  5570   later.  It is useful for constants whose behaviour is fixed axiomatically
  5571   rather than definitionally, such as the meta-logic connectives.
  5572 
  5573 * Pure: 'instance' now handles general arities with general sorts
  5574   (i.e. intersections of classes),
  5575 
  5576 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5577   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5578   It can be changed to alter the colors/layout of generated pages.
  5579 
  5580 
  5581 *** Isar ***
  5582 
  5583 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5584   cut_tac, subgoal_tac and thin_tac:
  5585   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5586     locales are no longer forced to write Isar proof scripts.
  5587     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5588     emulations.
  5589   - INCOMPATIBILITY: names of variables to be instantiated may no
  5590     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5591     This is consistent with the instantiation attribute "where".
  5592 
  5593 * Attributes "where" and "of":
  5594   - Now take type variables of instantiated theorem into account when reading
  5595     the instantiation string.  This fixes a bug that caused instantiated
  5596     theorems to have too special types in some circumstances.
  5597   - "where" permits explicit instantiations of type variables.
  5598 
  5599 * Calculation commands "moreover" and "also" no longer interfere with
  5600   current facts ("this"), admitting arbitrary combinations with "then"
  5601   and derived forms.
  5602 
  5603 * Locales:
  5604   - Goal statements involving the context element "includes" no longer
  5605     generate theorems with internal delta predicates (those ending on
  5606     "_axioms") in the premise.
  5607     Resolve particular premise with <locale>.intro to obtain old form.
  5608   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5609     specification and "includes" elements in goal statement.
  5610   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5611     [intro?] and [elim?] (respectively) by default.
  5612   - Experimental command for instantiation of locales in proof contexts:
  5613         instantiate <label>[<attrs>]: <loc>
  5614     Instantiates locale <loc> and adds all its theorems to the current context
  5615     taking into account their attributes.  Label and attrs are optional
  5616     modifiers, like in theorem declarations.  If present, names of
  5617     instantiated theorems are qualified with <label>, and the attributes
  5618     <attrs> are applied after any attributes these theorems might have already.
  5619       If the locale has assumptions, a chained fact of the form
  5620     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5621     are derived.  The command does not support old-style locales declared
  5622     with "locale (open)".
  5623       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5624 
  5625 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5626   (Isar) contexts.
  5627 
  5628 
  5629 *** HOL ***
  5630 
  5631 * Proof import: new image HOL4 contains the imported library from
  5632   the HOL4 system with about 2500 theorems. It is imported by
  5633   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5634   can be used like any other Isabelle image.  See
  5635   HOL/Import/HOL/README for more information.
  5636 
  5637 * Simplifier:
  5638   - Much improved handling of linear and partial orders.
  5639     Reasoners for linear and partial orders are set up for type classes
  5640     "linorder" and "order" respectively, and are added to the default simpset
  5641     as solvers.  This means that the simplifier can build transitivity chains
  5642     to solve goals from the assumptions.
  5643   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5644     of blast or auto after simplification become unnecessary because the goal
  5645     is solved by simplification already.
  5646 
  5647 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5648     all proved in axiomatic type classes for semirings, rings and fields.
  5649 
  5650 * Numerics:
  5651   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5652     now formalized using the Ring_and_Field theory mentioned above.
  5653   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5654     than before, because now they are set up once in a generic manner.
  5655   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5656     Look for the general versions in Ring_and_Field (and Power if they concern
  5657     exponentiation).
  5658 
  5659 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5660 
  5661 * Records:
  5662   - Record types are now by default printed with their type abbreviation
  5663     instead of the list of all field types. This can be configured via
  5664     the reference "print_record_type_abbr".
  5665   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5666     (not enabled by default).
  5667   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5668     EX x. x = sel r to True (not enabled by default).
  5669   - Tactic "record_split_simp_tac" to split and simplify records added.
  5670 
  5671 * 'specification' command added, allowing for definition by
  5672   specification.  There is also an 'ax_specification' command that
  5673   introduces the new constants axiomatically.
  5674 
  5675 * arith(_tac) is now able to generate counterexamples for reals as well.
  5676 
  5677 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5678 
  5679 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5680   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5681 
  5682 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5683   matrix theory to linear programming.
  5684 
  5685 * Unions and Intersections:
  5686   The latex output syntax of UN and INT has been changed
  5687   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5688   i.e. the index formulae has become a subscript.
  5689   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5690 
  5691 * Unions and Intersections over Intervals:
  5692   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5693   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5694   like in normal math, and corresponding versions for < and for intersection.
  5695 
  5696 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5697   lexicographic dictonary ordering has been added as "lexord".
  5698 
  5699 * ML: the legacy theory structures Int and List have been removed. They had
  5700   conflicted with ML Basis Library structures having the same names.
  5701 
  5702 * 'refute' command added to search for (finite) countermodels.  Only works
  5703   for a fragment of HOL.  The installation of an external SAT solver is
  5704   highly recommended.  See "HOL/Refute.thy" for details.
  5705 
  5706 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5707   formulae under an assignment of free variables to random values.
  5708   In contrast to 'refute', it can deal with inductive datatypes,
  5709   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5710   for examples.
  5711 
  5712 
  5713 *** HOLCF ***
  5714 
  5715 * Streams now come with concatenation and are part of the HOLCF image
  5716 
  5717 
  5718 
  5719 New in Isabelle2003 (May 2003)
  5720 ------------------------------
  5721 
  5722 *** General ***
  5723 
  5724 * Provers/simplifier:
  5725 
  5726   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5727     Assumptions are now subject to complete mutual simplification,
  5728     not just from left to right. The simplifier now preserves
  5729     the order of assumptions.
  5730 
  5731     Potential INCOMPATIBILITY:
  5732 
  5733     -- simp sometimes diverges where the old version did
  5734        not, e.g. invoking simp on the goal
  5735 
  5736         [| P (f x); y = x; f x = f y |] ==> Q
  5737 
  5738        now gives rise to the infinite reduction sequence
  5739 
  5740         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5741 
  5742        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5743        kind of problem.
  5744 
  5745     -- Tactics combining classical reasoner and simplification (such as auto)
  5746        are also affected by this change, because many of them rely on
  5747        simp. They may sometimes diverge as well or yield a different numbers
  5748        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5749        in case of problems. Sometimes subsequent calls to the classical
  5750        reasoner will fail because a preceeding call to the simplifier too
  5751        eagerly simplified the goal, e.g. deleted redundant premises.
  5752 
  5753   - The simplifier trace now shows the names of the applied rewrite rules
  5754 
  5755   - You can limit the number of recursive invocations of the simplifier
  5756     during conditional rewriting (where the simplifie tries to solve the
  5757     conditions before applying the rewrite rule):
  5758     ML "simp_depth_limit := n"
  5759     where n is an integer. Thus you can force termination where previously
  5760     the simplifier would diverge.
  5761 
  5762   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5763 
  5764   - No longer aborts on failed congruence proof.  Instead, the
  5765     congruence is ignored.
  5766 
  5767 * Pure: New generic framework for extracting programs from constructive
  5768   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5769   as HOL/Extraction for some case studies.
  5770 
  5771 * Pure: The main goal of the proof state is no longer shown by default, only
  5772 the subgoals. This behaviour is controlled by a new flag.
  5773    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5774 (ML: Proof.show_main_goal).
  5775 
  5776 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5777 rules whose conclusion matches subgoal 1:
  5778       PG menu: Isabelle/Isar -> Show me -> matching rules
  5779 The rules are ordered by how closely they match the subgoal.
  5780 In particular, rules that solve a subgoal outright are displayed first
  5781 (or rather last, the way they are printed).
  5782 (ML: ProofGeneral.print_intros())
  5783 
  5784 * Pure: New flag trace_unify_fail causes unification to print
  5785 diagnostic information (PG: in trace buffer) when it fails. This is
  5786 useful for figuring out why single step proofs like rule, erule or
  5787 assumption failed.
  5788 
  5789 * Pure: Locale specifications now produce predicate definitions
  5790 according to the body of text (covering assumptions modulo local
  5791 definitions); predicate "loc_axioms" covers newly introduced text,
  5792 while "loc" is cumulative wrt. all included locale expressions; the
  5793 latter view is presented only on export into the global theory
  5794 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5795 on the old view without predicates;
  5796 
  5797 * Pure: predefined locales "var" and "struct" are useful for sharing
  5798 parameters (as in CASL, for example); just specify something like
  5799 ``var x + var y + struct M'' as import;
  5800 
  5801 * Pure: improved thms_containing: proper indexing of facts instead of
  5802 raw theorems; check validity of results wrt. current name space;
  5803 include local facts of proof configuration (also covers active
  5804 locales), cover fixed variables in index; may use "_" in term
  5805 specification; an optional limit for the number of printed facts may
  5806 be given (the default is 40);
  5807 
  5808 * Pure: disallow duplicate fact bindings within new-style theory files
  5809 (batch-mode only);
  5810 
  5811 * Provers: improved induct method: assumptions introduced by case
  5812 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5813 the goal statement); "foo" still refers to all facts collectively;
  5814 
  5815 * Provers: the function blast.overloaded has been removed: all constants
  5816 are regarded as potentially overloaded, which improves robustness in exchange
  5817 for slight decrease in efficiency;
  5818 
  5819 * Provers/linorder: New generic prover for transitivity reasoning over
  5820 linear orders.  Note: this prover is not efficient!
  5821 
  5822 * Isar: preview of problems to finish 'show' now produce an error
  5823 rather than just a warning (in interactive mode);
  5824 
  5825 
  5826 *** HOL ***
  5827 
  5828 * arith(_tac)
  5829 
  5830  - Produces a counter example if it cannot prove a goal.
  5831    Note that the counter example may be spurious if the goal is not a formula
  5832    of quantifier-free linear arithmetic.
  5833    In ProofGeneral the counter example appears in the trace buffer.
  5834 
  5835  - Knows about div k and mod k where k is a numeral of type nat or int.
  5836 
  5837  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5838    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5839    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5840 
  5841 * simp's arithmetic capabilities have been enhanced a bit: it now
  5842 takes ~= in premises into account (by performing a case split);
  5843 
  5844 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5845 are distributed over a sum of terms;
  5846 
  5847 * New tactic "trans_tac" and method "trans" instantiate
  5848 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5849 "<=", "<" and "=").
  5850 
  5851 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5852 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5853 
  5854 * 'typedef' command has new option "open" to suppress the set
  5855 definition;
  5856 
  5857 * functions Min and Max on finite sets have been introduced (theory
  5858 Finite_Set);
  5859 
  5860 * attribute [symmetric] now works for relations as well; it turns
  5861 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5862 
  5863 * induct over a !!-quantified statement (say !!x1..xn):
  5864   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5865 
  5866 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5867 %x. None. Warning: empty_def now refers to the previously hidden definition
  5868 of the empty set.
  5869 
  5870 * Algebra: formalization of classical algebra.  Intended as base for
  5871 any algebraic development in Isabelle.  Currently covers group theory
  5872 (up to Sylow's theorem) and ring theory (Universal Property of
  5873 Univariate Polynomials).  Contributions welcome;
  5874 
  5875 * GroupTheory: deleted, since its material has been moved to Algebra;
  5876 
  5877 * Complex: new directory of the complex numbers with numeric constants,
  5878 nonstandard complex numbers, and some complex analysis, standard and
  5879 nonstandard (Jacques Fleuriot);
  5880 
  5881 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5882 
  5883 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5884 Fleuriot);
  5885 
  5886 * Real/HahnBanach: updated and adapted to locales;
  5887 
  5888 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5889 Gray and Kramer);
  5890 
  5891 * UNITY: added the Meier-Sanders theory of progress sets;
  5892 
  5893 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5894 as abstract algorithms, instantiated to the JVM;
  5895 
  5896 * Bali: Java source language formalization. Type system, operational
  5897 semantics, axiomatic semantics. Supported language features:
  5898 classes, interfaces, objects,virtual methods, static methods,
  5899 static/instance fields, arrays, access modifiers, definite
  5900 assignment, exceptions.
  5901 
  5902 
  5903 *** ZF ***
  5904 
  5905 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5906 universe, etc.);
  5907 
  5908 * Main ZF: virtually all theories converted to new-style format;
  5909 
  5910 
  5911 *** ML ***
  5912 
  5913 * Pure: Tactic.prove provides sane interface for internal proofs;
  5914 omits the infamous "standard" operation, so this is more appropriate
  5915 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5916 
  5917 * Pure: improved error reporting of simprocs;
  5918 
  5919 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5920 up simprocs;
  5921 
  5922 
  5923 *** Document preparation ***
  5924 
  5925 * uses \par instead of \\ for line breaks in theory text. This may
  5926 shift some page breaks in large documents. To get the old behaviour
  5927 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5928 
  5929 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5930 other packages
  5931 
  5932 * \<euro> now needs package babel/greek instead of marvosym (which
  5933 broke \Rightarrow)
  5934 
  5935 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5936 textcomp package)
  5937 
  5938 
  5939 
  5940 New in Isabelle2002 (March 2002)
  5941 --------------------------------
  5942 
  5943 *** Document preparation ***
  5944 
  5945 * greatly simplified document preparation setup, including more
  5946 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5947 instructive isatool mkdir; users should basically be able to get
  5948 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5949 users may run a separate document processing stage manually like this:
  5950 "isatool usedir -D output HOL Test && isatool document Test/output";
  5951 
  5952 * theory dependency graph may now be incorporated into documents;
  5953 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5954 with \includegraphics of LaTeX;
  5955 
  5956 * proper spacing of consecutive markup elements, especially text
  5957 blocks after section headings;
  5958 
  5959 * support bold style (for single symbols only), input syntax is like
  5960 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5961 
  5962 * \<bullet> is now output as bold \cdot by default, which looks much
  5963 better in printed text;
  5964 
  5965 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5966 note that these symbols are currently unavailable in Proof General /
  5967 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5968 
  5969 * isatool latex no longer depends on changed TEXINPUTS, instead
  5970 isatool document copies the Isabelle style files to the target
  5971 location;
  5972 
  5973 
  5974 *** Isar ***
  5975 
  5976 * Pure/Provers: improved proof by cases and induction;
  5977   - 'case' command admits impromptu naming of parameters (such as
  5978     "case (Suc n)");
  5979   - 'induct' method divinates rule instantiation from the inductive
  5980     claim; no longer requires excessive ?P bindings for proper
  5981     instantiation of cases;
  5982   - 'induct' method properly enumerates all possibilities of set/type
  5983     rules; as a consequence facts may be also passed through *type*
  5984     rules without further ado;
  5985   - 'induct' method now derives symbolic cases from the *rulified*
  5986     rule (before it used to rulify cases stemming from the internal
  5987     atomized version); this means that the context of a non-atomic
  5988     statement becomes is included in the hypothesis, avoiding the
  5989     slightly cumbersome show "PROP ?case" form;
  5990   - 'induct' may now use elim-style induction rules without chaining
  5991     facts, using ``missing'' premises from the goal state; this allows
  5992     rules stemming from inductive sets to be applied in unstructured
  5993     scripts, while still benefitting from proper handling of non-atomic
  5994     statements; NB: major inductive premises need to be put first, all
  5995     the rest of the goal is passed through the induction;
  5996   - 'induct' proper support for mutual induction involving non-atomic
  5997     rule statements (uses the new concept of simultaneous goals, see
  5998     below);
  5999   - append all possible rule selections, but only use the first
  6000     success (no backtracking);
  6001   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6002   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6003   - added 'print_induct_rules' (covered by help item in recent Proof
  6004     General versions);
  6005   - moved induct/cases attributes to Pure, methods to Provers;
  6006   - generic method setup instantiated for FOL and HOL;
  6007 
  6008 * Pure: support multiple simultaneous goal statements, for example
  6009 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6010 meta-level mechanism, this acts as if several individual goals had
  6011 been stated separately; in particular common proof methods need to be
  6012 repeated in order to cover all claims; note that a single elimination
  6013 step is *not* sufficient to establish the two conjunctions, so this
  6014 fails:
  6015 
  6016   assume "A & B" then have A and B ..   (*".." fails*)
  6017 
  6018 better use "obtain" in situations as above; alternative refer to
  6019 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6020 
  6021 * Pure: proper integration with ``locales''; unlike the original
  6022 version by Florian Kammller, Isar locales package high-level proof
  6023 contexts rather than raw logical ones (e.g. we admit to include
  6024 attributes everywhere); operations on locales include merge and
  6025 rename; support for implicit arguments (``structures''); simultaneous
  6026 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6027 some examples;
  6028 
  6029 * Pure: the following commands have been ``localized'', supporting a
  6030 target locale specification "(in name)": 'lemma', 'theorem',
  6031 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6032 stored both within the locale and at the theory level (exported and
  6033 qualified by the locale name);
  6034 
  6035 * Pure: theory goals may now be specified in ``long'' form, with
  6036 ad-hoc contexts consisting of arbitrary locale elements. for example
  6037 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6038 definitions may be given, too); the result is a meta-level rule with
  6039 the context elements being discharged in the obvious way;
  6040 
  6041 * Pure: new proof command 'using' allows to augment currently used
  6042 facts after a goal statement ('using' is syntactically analogous to
  6043 'apply', but acts on the goal's facts only); this allows chained facts
  6044 to be separated into parts given before and after a claim, as in
  6045 ``from a and b have C using d and e <proof>'';
  6046 
  6047 * Pure: renamed "antecedent" case to "rule_context";
  6048 
  6049 * Pure: new 'judgment' command records explicit information about the
  6050 object-logic embedding (used by several tools internally); no longer
  6051 use hard-wired "Trueprop";
  6052 
  6053 * Pure: added 'corollary' command;
  6054 
  6055 * Pure: fixed 'token_translation' command;
  6056 
  6057 * Pure: removed obsolete 'exported' attribute;
  6058 
  6059 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6060 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6061 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6062 
  6063 * Pure: method 'atomize' presents local goal premises as object-level
  6064 statements (atomic meta-level propositions); setup controlled via
  6065 rewrite rules declarations of 'atomize' attribute; example
  6066 application: 'induct' method with proper rule statements in improper
  6067 proof *scripts*;
  6068 
  6069 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6070 now consider the syntactic context of assumptions, giving a better
  6071 chance to get type-inference of the arguments right (this is
  6072 especially important for locales);
  6073 
  6074 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6075 mode;
  6076 
  6077 * Pure/obtain: the formal conclusion "thesis", being marked as
  6078 ``internal'', may no longer be reference directly in the text;
  6079 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6080 situations;
  6081 
  6082 * Pure: generic 'sym' attribute which declares a rule both as pure
  6083 'elim?' and for the 'symmetric' operation;
  6084 
  6085 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6086 text; the fixed correlation with particular command syntax has been
  6087 discontinued;
  6088 
  6089 * Pure: new method 'rules' is particularly well-suited for proof
  6090 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6091 but often produces more compact proof terms with less detours;
  6092 
  6093 * Pure/Provers/classical: simplified integration with pure rule
  6094 attributes and methods; the classical "intro?/elim?/dest?"
  6095 declarations coincide with the pure ones; the "rule" method no longer
  6096 includes classically swapped intros; "intro" and "elim" methods no
  6097 longer pick rules from the context; also got rid of ML declarations
  6098 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6099 INCOMPATIBILITY;
  6100 
  6101 * Provers/classical: attribute 'swapped' produces classical inversions
  6102 of introduction rules;
  6103 
  6104 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6105 rules instead of full simplifier context; 'iff' attribute handles
  6106 conditional rules;
  6107 
  6108 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6109 
  6110 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6111 "(permissive)" option to recover old behavior;
  6112 
  6113 * HOL: 'inductive' no longer features separate (collective) attributes
  6114 for 'intros' (was found too confusing);
  6115 
  6116 * HOL: properly declared induction rules less_induct and
  6117 wf_induct_rule;
  6118 
  6119 
  6120 *** HOL ***
  6121 
  6122 * HOL: moved over to sane numeral syntax; the new policy is as
  6123 follows:
  6124 
  6125   - 0 and 1 are polymorphic constants, which are defined on any
  6126   numeric type (nat, int, real etc.);
  6127 
  6128   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6129   binary representation internally;
  6130 
  6131   - type nat has special constructor Suc, and generally prefers Suc 0
  6132   over 1::nat and Suc (Suc 0) over 2::nat;
  6133 
  6134 This change may cause significant problems of INCOMPATIBILITY; here
  6135 are some hints on converting existing sources:
  6136 
  6137   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6138   entities, so expressions involving "-" (unary or binary minus) need
  6139   to be spaced properly;
  6140 
  6141   - existing occurrences of "1" may need to be constraint "1::nat" or
  6142   even replaced by Suc 0; similar for old "2";
  6143 
  6144   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6145 
  6146   - remove all special provisions on numerals in proofs;
  6147 
  6148 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6149 representation (depends on bin_arith_simps in the default context);
  6150 
  6151 * HOL: symbolic syntax for x^2 (numeral 2);
  6152 
  6153 * HOL: the class of all HOL types is now called "type" rather than
  6154 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6155 in axclass/classes, instance/arities, and (usually rare) occurrences
  6156 in typings (of consts etc.); internally the class is called
  6157 "HOL.type", ML programs should refer to HOLogic.typeS;
  6158 
  6159 * HOL/record package improvements:
  6160   - new derived operations "fields" to build a partial record section,
  6161     "extend" to promote a fixed record to a record scheme, and
  6162     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6163     declared as simp by default;
  6164   - shared operations ("more", "fields", etc.) now need to be always
  6165     qualified) --- potential INCOMPATIBILITY;
  6166   - removed "make_scheme" operations (use "make" with "extend") --
  6167     INCOMPATIBILITY;
  6168   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6169   - provides cases/induct rules for use with corresponding Isar
  6170     methods (for concrete records, record schemes, concrete more
  6171     parts, and schematic more parts -- in that order);
  6172   - internal definitions directly based on a light-weight abstract
  6173     theory of product types over typedef rather than datatype;
  6174 
  6175 * HOL: generic code generator for generating executable ML code from
  6176 specifications; specific support for HOL constructs such as inductive
  6177 datatypes and sets, as well as recursive functions; can be invoked
  6178 via 'generate_code' theory section;
  6179 
  6180 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6181 
  6182 * HOL: consolidated and renamed several theories.  In particular:
  6183         Ord.thy has been absorbed into HOL.thy
  6184         String.thy has been absorbed into List.thy
  6185 
  6186 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6187 (beware of argument permutation!);
  6188 
  6189 * HOL: linorder_less_split superseded by linorder_cases;
  6190 
  6191 * HOL/List: "nodups" renamed to "distinct";
  6192 
  6193 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6194 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6195   - Ex_def has changed, now need to use some_eq_ex
  6196 
  6197 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6198 in this (rare) case use:
  6199 
  6200   delSWrapper "split_all_tac"
  6201   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6202 
  6203 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6204 MAY FAIL;
  6205 
  6206 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6207 Isabelle's type classes, ^ on functions and relations has too general
  6208 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6209 necessary to attach explicit type constraints;
  6210 
  6211 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6212 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6213 renamed accordingly (eg "compI" -> "rel_compI").
  6214 
  6215 * HOL: syntax translations now work properly with numerals and records
  6216 expressions;
  6217 
  6218 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6219 of "lam" -- INCOMPATIBILITY;
  6220 
  6221 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6222 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6223 renamed "Product_Type.unit";
  6224 
  6225 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6226 
  6227 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6228 the "cases" method);
  6229 
  6230 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6231 Florian Kammller);
  6232 
  6233 * HOL/IMP: updated and converted to new-style theory format; several
  6234 parts turned into readable document, with proper Isar proof texts and
  6235 some explanations (by Gerwin Klein);
  6236 
  6237 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6238 
  6239 * HOL-Hyperreal is now a logic image;
  6240 
  6241 
  6242 *** HOLCF ***
  6243 
  6244 * Isar: consts/constdefs supports mixfix syntax for continuous
  6245 operations;
  6246 
  6247 * Isar: domain package adapted to new-style theory format, e.g. see
  6248 HOLCF/ex/Dnat.thy;
  6249 
  6250 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6251 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6252 lift.induct_tac, always use UU instead of Undef;
  6253 
  6254 * HOLCF/IMP: updated and converted to new-style theory;
  6255 
  6256 
  6257 *** ZF ***
  6258 
  6259 * Isar: proper integration of logic-specific tools and packages,
  6260 including theory commands '(co)inductive', '(co)datatype',
  6261 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6262 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6263 
  6264 * theory Main no longer includes AC; for the Axiom of Choice, base
  6265 your theory on Main_ZFC;
  6266 
  6267 * the integer library now covers quotients and remainders, with many
  6268 laws relating division to addition, multiplication, etc.;
  6269 
  6270 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6271 typeless version of the formalism;
  6272 
  6273 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6274 format;
  6275 
  6276 * ZF/Induct: new directory for examples of inductive definitions,
  6277 including theory Multiset for multiset orderings; converted to
  6278 new-style theory format;
  6279 
  6280 * ZF: many new theorems about lists, ordinals, etc.;
  6281 
  6282 
  6283 *** General ***
  6284 
  6285 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6286 variable proof controls level of detail: 0 = no proofs (only oracle
  6287 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6288 also ref manual for further ML interfaces;
  6289 
  6290 * Pure/axclass: removed obsolete ML interface
  6291 goal_subclass/goal_arity;
  6292 
  6293 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6294 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6295 separate tokens, so expressions involving minus need to be spaced
  6296 properly;
  6297 
  6298 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6299 rather than "infixl" or "infixr";
  6300 
  6301 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6302 sort constraint specifications in type inference; e.g. "x::_::foo"
  6303 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6304 type variable);
  6305 
  6306 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6307 control output of nested => (types); the default behavior is
  6308 "type_brackets";
  6309 
  6310 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6311 tokens into AST constants;
  6312 
  6313 * Pure/syntax: prefer later declarations of translations and print
  6314 translation functions; potential INCOMPATIBILITY: need to reverse
  6315 multiple declarations for same syntax element constant;
  6316 
  6317 * Pure/show_hyps reset by default (in accordance to existing Isar
  6318 practice);
  6319 
  6320 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6321 addSafter;
  6322 
  6323 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6324 as well;
  6325 
  6326 * system: tested support for MacOS X; should be able to get Isabelle +
  6327 Proof General to work in a plain Terminal after installing Poly/ML
  6328 (e.g. from the Isabelle distribution area) and GNU bash alone
  6329 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6330 support requires further installations, e.g. from
  6331 http://fink.sourceforge.net/);
  6332 
  6333 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6334 
  6335 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6336 of 40 MB), cf. ML_OPTIONS;
  6337 
  6338 * system: Proof General keywords specification is now part of the
  6339 Isabelle distribution (see etc/isar-keywords.el);
  6340 
  6341 * system: support for persistent Proof General sessions (refrain from
  6342 outdating all loaded theories on startup); user may create writable
  6343 logic images like this: ``isabelle -q HOL Test'';
  6344 
  6345 * system: smart selection of Isabelle process versus Isabelle
  6346 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6347 run both "isabelle" and "Isabelle" even if file names are badly
  6348 damaged (executable inspects the case of the first letter of its own
  6349 name); added separate "isabelle-process" and "isabelle-interface";
  6350 
  6351 * system: refrain from any attempt at filtering input streams; no
  6352 longer support ``8bit'' encoding of old isabelle font, instead proper
  6353 iso-latin characters may now be used; the related isatools
  6354 "symbolinput" and "nonascii" have disappeared as well;
  6355 
  6356 * system: removed old "xterm" interface (the print modes "xterm" and
  6357 "xterm_color" are still available for direct use in a suitable
  6358 terminal);
  6359 
  6360 
  6361 
  6362 New in Isabelle99-2 (February 2001)
  6363 -----------------------------------
  6364 
  6365 *** Overview of INCOMPATIBILITIES ***
  6366 
  6367 * HOL: please note that theories in the Library and elsewhere often use the
  6368 new-style (Isar) format; to refer to their theorems in an ML script you must
  6369 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6370 
  6371 * HOL: inductive package no longer splits induction rule aggressively,
  6372 but only as far as specified by the introductions given; the old
  6373 format may be recovered via ML function complete_split_rule or attribute
  6374 'split_rule (complete)';
  6375 
  6376 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6377 gfp_Tarski to gfp_unfold;
  6378 
  6379 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6380 
  6381 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6382 relation); infix "^^" has been renamed "``"; infix "``" has been
  6383 renamed "`"; "univalent" has been renamed "single_valued";
  6384 
  6385 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6386 operation;
  6387 
  6388 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6389 
  6390 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6391 
  6392 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6393 consequence, it is no longer monotonic wrt. the local goal context
  6394 (which is now passed through the inductive cases);
  6395 
  6396 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6397 \<gg> to \<ggreater>;
  6398 
  6399 
  6400 *** Document preparation ***
  6401 
  6402 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6403 available: are "it" for near math-mode best-style output, "sl" for
  6404 slanted text style, and "tt" for plain type-writer; if no
  6405 \isabellestyle command is given, output is according to slanted
  6406 type-writer);
  6407 
  6408 * support sub/super scripts (for single symbols only), input syntax is
  6409 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6410 
  6411 * some more standard symbols; see Appendix A of the system manual for
  6412 the complete list of symbols defined in isabellesym.sty;
  6413 
  6414 * improved isabelle style files; more abstract symbol implementation
  6415 (should now use \isamath{...} and \isatext{...} in custom symbol
  6416 definitions);
  6417 
  6418 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6419 state; Note that presentation of goal states does not conform to
  6420 actual human-readable proof documents.  Please do not include goal
  6421 states into document output unless you really know what you are doing!
  6422 
  6423 * proper indentation of antiquoted output with proportional LaTeX
  6424 fonts;
  6425 
  6426 * no_document ML operator temporarily disables LaTeX document
  6427 generation;
  6428 
  6429 * isatool unsymbolize tunes sources for plain ASCII communication;
  6430 
  6431 
  6432 *** Isar ***
  6433 
  6434 * Pure: Isar now suffers initial goal statements to contain unbound
  6435 schematic variables (this does not conform to actual readable proof
  6436 documents, due to unpredictable outcome and non-compositional proof
  6437 checking); users who know what they are doing may use schematic goals
  6438 for Prolog-style synthesis of proven results;
  6439 
  6440 * Pure: assumption method (an implicit finishing) now handles actual
  6441 rules as well;
  6442 
  6443 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6444 initial goal, declare "that" only as Pure intro (only for single
  6445 steps); the "that" rule assumption may now be involved in implicit
  6446 finishing, thus ".." becomes a feasible for trivial obtains;
  6447 
  6448 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6449 instance proofs may be performed by "..";
  6450 
  6451 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6452 statements as well;
  6453 
  6454 * Pure: more robust selection of calculational rules;
  6455 
  6456 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6457 rule (as well as the assumption rule);
  6458 
  6459 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6460 lemmas, using the graph browser tool;
  6461 
  6462 * Pure: predict failure of "show" in interactive mode;
  6463 
  6464 * Pure: 'thms_containing' now takes actual terms as arguments;
  6465 
  6466 * HOL: improved method 'induct' --- now handles non-atomic goals
  6467 (potential INCOMPATIBILITY); tuned error handling;
  6468 
  6469 * HOL: cases and induct rules now provide explicit hints about the
  6470 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6471 any remaining facts are inserted into the goal verbatim;
  6472 
  6473 * HOL: local contexts (aka cases) may now contain term bindings as
  6474 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6475 the result to be shown in each case;
  6476 
  6477 * HOL: added 'recdef_tc' command;
  6478 
  6479 * isatool convert assists in eliminating legacy ML scripts;
  6480 
  6481 
  6482 *** HOL ***
  6483 
  6484 * HOL/Library: a collection of generic theories to be used together
  6485 with main HOL; the theory loader path already includes this directory
  6486 by default; the following existing theories have been moved here:
  6487 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6488 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6489 
  6490 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6491 modelling and verification task performed in Isabelle/HOL +
  6492 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6493 
  6494 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6495 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6496 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6497 'domain', this makes the theory consistent with mathematical
  6498 literature;
  6499 
  6500 * HOL basics: added overloaded operations "inverse" and "divide"
  6501 (infix "/"), syntax for generic "abs" operation, generic summation
  6502 operator \<Sum>;
  6503 
  6504 * HOL/typedef: simplified package, provide more useful rules (see also
  6505 HOL/subset.thy);
  6506 
  6507 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6508 now expressed as a proper nested rule (old-style tactic scripts may
  6509 require atomize_strip_tac to cope with non-atomic premises);
  6510 
  6511 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6512 to "split_conv" (old name still available for compatibility);
  6513 
  6514 * HOL: improved concrete syntax for strings (e.g. allows translation
  6515 rules with string literals);
  6516 
  6517 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6518  and Fleuriot's mechanization of analysis, including the transcendental
  6519  functions for the reals;
  6520 
  6521 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6522 
  6523 
  6524 *** CTT ***
  6525 
  6526 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6527 "lam" is displayed as TWO lambda-symbols
  6528 
  6529 * CTT: theory Main now available, containing everything (that is, Bool
  6530 and Arith);
  6531 
  6532 
  6533 *** General ***
  6534 
  6535 * Pure: the Simplifier has been implemented properly as a derived rule
  6536 outside of the actual kernel (at last!); the overall performance
  6537 penalty in practical applications is about 50%, while reliability of
  6538 the Isabelle inference kernel has been greatly improved;
  6539 
  6540 * print modes "brackets" and "no_brackets" control output of nested =>
  6541 (types) and ==> (props); the default behaviour is "brackets";
  6542 
  6543 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6544 as assumptions as well;
  6545 
  6546 * system: support Poly/ML 4.0;
  6547 
  6548 * system: isatool install handles KDE version 1 or 2;
  6549 
  6550 
  6551 
  6552 New in Isabelle99-1 (October 2000)
  6553 ----------------------------------
  6554 
  6555 *** Overview of INCOMPATIBILITIES ***
  6556 
  6557 * HOL: simplification of natural numbers is much changed; to partly
  6558 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6559 issue the following ML commands:
  6560 
  6561   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6562   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6563 
  6564 * HOL: simplification no longer dives into case-expressions; this is
  6565 controlled by "t.weak_case_cong" for each datatype t;
  6566 
  6567 * HOL: nat_less_induct renamed to less_induct;
  6568 
  6569 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6570 fixsome to patch .thy and .ML sources automatically;
  6571 
  6572   select_equality  -> some_equality
  6573   select_eq_Ex     -> some_eq_ex
  6574   selectI2EX       -> someI2_ex
  6575   selectI2         -> someI2
  6576   selectI          -> someI
  6577   select1_equality -> some1_equality
  6578   Eps_sym_eq       -> some_sym_eq_trivial
  6579   Eps_eq           -> some_eq_trivial
  6580 
  6581 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6582 
  6583 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6584 instead);
  6585 
  6586 * HOL: the recursion equations generated by 'recdef' are now called
  6587 f.simps instead of f.rules;
  6588 
  6589 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6590 
  6591 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6592 sometimes be needed;
  6593 
  6594 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6595 
  6596 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6597 
  6598 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6599 product is now "<*>" instead of "Times"; the lexicographic product is
  6600 now "<*lex*>" instead of "**";
  6601 
  6602 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6603 of main HOL, but was unused); better use HOL's datatype package;
  6604 
  6605 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6606 the old syntax may be recovered as follows:
  6607 
  6608   syntax (symbols)
  6609     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6610       (infixl "\\<oplus>" 100)
  6611 
  6612 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6613 
  6614 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6615 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6616 internally;
  6617 
  6618 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6619 changed from A/r to A//r;
  6620 
  6621 * ZF: new treatment of arithmetic (nat & int) may break some old
  6622 proofs;
  6623 
  6624 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6625 rulify -> rule_format, elimify -> elim_format, ...);
  6626 
  6627 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6628 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6629 should have to change intro!! to intro? only); replaced "delrule" by
  6630 "rule del";
  6631 
  6632 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6633 
  6634 * Provers: strengthened force_tac by using new first_best_tac;
  6635 
  6636 * LaTeX document preparation: several changes of isabelle.sty (see
  6637 lib/texinputs);
  6638 
  6639 
  6640 *** Document preparation ***
  6641 
  6642 * formal comments (text blocks etc.) in new-style theories may now
  6643 contain antiquotations of thm/prop/term/typ/text to be presented
  6644 according to latex print mode; concrete syntax is like this:
  6645 @{term[show_types] "f(x) = a + x"};
  6646 
  6647 * isatool mkdir provides easy setup of Isabelle session directories,
  6648 including proper document sources;
  6649 
  6650 * generated LaTeX sources are now deleted after successful run
  6651 (isatool document -c); may retain a copy somewhere else via -D option
  6652 of isatool usedir;
  6653 
  6654 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6655 style files, achieving self-contained LaTeX sources and simplifying
  6656 LaTeX debugging;
  6657 
  6658 * old-style theories now produce (crude) LaTeX output as well;
  6659 
  6660 * browser info session directories are now self-contained (may be put
  6661 on WWW server seperately); improved graphs of nested sessions; removed
  6662 graph for 'all sessions';
  6663 
  6664 * several improvements in isabelle style files; \isabellestyle{it}
  6665 produces fake math mode output; \isamarkupheader is now \section by
  6666 default; see lib/texinputs/isabelle.sty etc.;
  6667 
  6668 
  6669 *** Isar ***
  6670 
  6671 * Isar/Pure: local results and corresponding term bindings are now
  6672 subject to Hindley-Milner polymorphism (similar to ML); this
  6673 accommodates incremental type-inference very nicely;
  6674 
  6675 * Isar/Pure: new derived language element 'obtain' supports
  6676 generalized existence reasoning;
  6677 
  6678 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6679 support accumulation of results, without applying any rules yet;
  6680 useful to collect intermediate results without explicit name
  6681 references, and for use with transitivity rules with more than 2
  6682 premises;
  6683 
  6684 * Isar/Pure: scalable support for case-analysis type proofs: new
  6685 'case' language element refers to local contexts symbolically, as
  6686 produced by certain proof methods; internally, case names are attached
  6687 to theorems as "tags";
  6688 
  6689 * Isar/Pure: theory command 'hide' removes declarations from
  6690 class/type/const name spaces;
  6691 
  6692 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6693 indicate potential overloading;
  6694 
  6695 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6696 
  6697 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6698 "{a,b,c}" instead of {a,b,c};
  6699 
  6700 * Isar/Pure now provides its own version of intro/elim/dest
  6701 attributes; useful for building new logics, but beware of confusion
  6702 with the version in Provers/classical;
  6703 
  6704 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6705 case name 'antecedent';
  6706 
  6707 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6708 to the current context is now done automatically);
  6709 
  6710 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6711 for definining proof methods in ML;
  6712 
  6713 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6714 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6715 most cases, one should have to change intro!! to intro? only);
  6716 replaced "delrule" by "rule del";
  6717 
  6718 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6719 'symmetric' attribute (the latter supercedes [RS sym]);
  6720 
  6721 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6722 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6723 well (including splits);
  6724 
  6725 * Isar/Provers: Simplifier and Classical methods now support all kind
  6726 of modifiers used in the past, including 'cong', 'iff', etc.
  6727 
  6728 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6729 of Simplifier and Classical reasoner);
  6730 
  6731 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6732 now support named cases; major packages (inductive, datatype, primrec,
  6733 recdef) support case names and properly name parameters;
  6734 
  6735 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6736 monotonicity conditions are extracted to be proven at end of
  6737 calculations;
  6738 
  6739 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6740 method anyway;
  6741 
  6742 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6743 split_if split_if_asm; datatype package provides theorems foo.splits =
  6744 foo.split foo.split_asm for each datatype;
  6745 
  6746 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6747 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6748 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6749 use "(cases (simplified))" method in proper proof texts);
  6750 
  6751 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6752 
  6753 * Isar: names of theorems etc. may be natural numbers as well;
  6754 
  6755 * Isar: 'pr' command: optional arguments for goals_limit and
  6756 ProofContext.prems_limit; no longer prints theory contexts, but only
  6757 proof states;
  6758 
  6759 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6760 additional print modes to be specified; e.g. "pr(latex)" will print
  6761 proof state according to the Isabelle LaTeX style;
  6762 
  6763 * Isar: improved support for emulating tactic scripts, including proof
  6764 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6765 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6766 (for HOL datatypes);
  6767 
  6768 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6769 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6770 'proof method scripts' have to be in depth-first order;
  6771 
  6772 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6773 
  6774 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6775 should instead use individual commands for printing items
  6776 (print_commands, print_methods etc.);
  6777 
  6778 * Isar: added 'nothing' --- the empty list of theorems;
  6779 
  6780 
  6781 *** HOL ***
  6782 
  6783 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6784 corresponding virtual machine and a specification of its bytecode
  6785 verifier and a lightweight bytecode verifier, including proofs of
  6786 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6787 Cornelia Pusch (see also the homepage of project Bali at
  6788 http://isabelle.in.tum.de/Bali/);
  6789 
  6790 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6791 Clemens Ballarin;
  6792 
  6793 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6794 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6795 Rasmussen;
  6796 
  6797 * HOL/Lattice: fundamental concepts of lattice theory and order
  6798 structures, including duals, properties of bounds versus algebraic
  6799 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6800 Theorem for complete lattices etc.; may also serve as a demonstration
  6801 for abstract algebraic reasoning using axiomatic type classes, and
  6802 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6803 
  6804 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6805 von Oheimb;
  6806 
  6807 * HOL/IMPP: extension of IMP with local variables and mutually
  6808 recursive procedures, by David von Oheimb;
  6809 
  6810 * HOL/Lambda: converted into new-style theory and document;
  6811 
  6812 * HOL/ex/Multiquote: example of multiple nested quotations and
  6813 anti-quotations -- basically a generalized version of de-Bruijn
  6814 representation; very useful in avoiding lifting of operations;
  6815 
  6816 * HOL/record: added general record equality rule to simpset; fixed
  6817 select-update simplification procedure to handle extended records as
  6818 well; admit "r" as field name;
  6819 
  6820 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6821 other numeric types and also as the identity of groups, rings, etc.;
  6822 
  6823 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6824 Types nat and int belong to this axclass;
  6825 
  6826 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6827    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6828    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6829   two terms #m*u and #n*u are replaced by #(m+n)*u
  6830     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6831   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6832     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6833 
  6834 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6835 powerful prover for predicate logic but knows nothing of clasets; see
  6836 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6837 
  6838 * HOL: new version of "case_tac" subsumes both boolean case split and
  6839 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6840 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6841 
  6842 * HOL: simplification no longer dives into case-expressions: only the
  6843 selector expression is simplified, but not the remaining arms; to
  6844 enable full simplification of case-expressions for datatype t, you may
  6845 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6846 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6847 
  6848 * HOL/recdef: the recursion equations generated by 'recdef' for
  6849 function 'f' are now called f.simps instead of f.rules; if all
  6850 termination conditions are proved automatically, these simplification
  6851 rules are added to the simpset, as in primrec; rules may be named
  6852 individually as well, resulting in a separate list of theorems for
  6853 each equation;
  6854 
  6855 * HOL/While is a new theory that provides a while-combinator. It
  6856 permits the definition of tail-recursive functions without the
  6857 provision of a termination measure. The latter is necessary once the
  6858 invariant proof rule for while is applied.
  6859 
  6860 * HOL: new (overloaded) notation for the set of elements below/above
  6861 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6862 
  6863 * HOL: theorems impI, allI, ballI bound as "strip";
  6864 
  6865 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6866 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6867 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6868 
  6869 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6870 
  6871 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6872 main HOL, but was unused);
  6873 
  6874 * HOL: fewer consts declared as global (e.g. have to refer to
  6875 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6876 
  6877 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6878 in case of overlap with user translations (e.g. judgements over
  6879 tuples); (note that the underlying logical represenation is still
  6880 bogus);
  6881 
  6882 
  6883 *** ZF ***
  6884 
  6885 * ZF: simplification automatically cancels common terms in arithmetic
  6886 expressions over nat and int;
  6887 
  6888 * ZF: new treatment of nat to minimize type-checking: all operators
  6889 coerce their operands to a natural number using the function natify,
  6890 making the algebraic laws unconditional;
  6891 
  6892 * ZF: as above, for int: operators coerce their operands to an integer
  6893 using the function intify;
  6894 
  6895 * ZF: the integer library now contains many of the usual laws for the
  6896 orderings, including $<=, and monotonicity laws for $+ and $*;
  6897 
  6898 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6899 simplification;
  6900 
  6901 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6902 to the simplifier and classical reasoner simultaneously;
  6903 
  6904 
  6905 *** General ***
  6906 
  6907 * Provers: blast_tac now handles actual object-logic rules as
  6908 assumptions; note that auto_tac uses blast_tac internally as well;
  6909 
  6910 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6911 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6912 
  6913 * Provers: delrules now handles destruct rules as well (no longer need
  6914 explicit make_elim);
  6915 
  6916 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6917   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6918 use instead the strong form,
  6919   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6920 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6921 from destruct-rules;
  6922 
  6923 * Provers: Simplifier.easy_setup provides a fast path to basic
  6924 Simplifier setup for new object-logics;
  6925 
  6926 * Pure: AST translation rules no longer require constant head on LHS;
  6927 
  6928 * Pure: improved name spaces: ambiguous output is qualified; support
  6929 for hiding of names;
  6930 
  6931 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6932 XSYMBOL_HOME; no longer need to do manual configuration in most
  6933 situations;
  6934 
  6935 * system: compression of ML heaps images may now be controlled via -c
  6936 option of isabelle and isatool usedir (currently only observed by
  6937 Poly/ML);
  6938 
  6939 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6940 useful for remote X11);
  6941 
  6942 * system: provide TAGS file for Isabelle sources;
  6943 
  6944 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6945 order;
  6946 
  6947 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6948 timing flag supersedes proof_timing and Toplevel.trace;
  6949 
  6950 * ML: new combinators |>> and |>>> for incremental transformations
  6951 with secondary results (e.g. certain theory extensions):
  6952 
  6953 * ML: PureThy.add_defs gets additional argument to indicate potential
  6954 overloading (usually false);
  6955 
  6956 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6957 results;
  6958 
  6959 
  6960 
  6961 New in Isabelle99 (October 1999)
  6962 --------------------------------
  6963 
  6964 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6965 
  6966 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6967 are no longer simplified.  (This allows the simplifier to unfold recursive
  6968 functional programs.)  To restore the old behaviour, declare
  6969 
  6970     Delcongs [if_weak_cong];
  6971 
  6972 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6973 complement;
  6974 
  6975 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6976 
  6977 * HOL/datatype: mutual_induct_tac no longer exists --
  6978   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6979 
  6980 * HOL/typedef: fixed type inference for representing set; type
  6981 arguments now have to occur explicitly on the rhs as type constraints;
  6982 
  6983 * ZF: The con_defs part of an inductive definition may no longer refer
  6984 to constants declared in the same theory;
  6985 
  6986 * HOL, ZF: the function mk_cases, generated by the inductive
  6987 definition package, has lost an argument.  To simplify its result, it
  6988 uses the default simpset instead of a supplied list of theorems.
  6989 
  6990 * HOL/List: the constructors of type list are now Nil and Cons;
  6991 
  6992 * Simplifier: the type of the infix ML functions
  6993         setSSolver addSSolver setSolver addSolver
  6994 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6995 for packaging solvers. A solver is created via
  6996         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6997 where the string argument is only a comment.
  6998 
  6999 
  7000 *** Proof tools ***
  7001 
  7002 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7003 decision procedure for linear arithmetic. Currently it is used for
  7004 types `nat', `int', and `real' in HOL (see below); it can, should and
  7005 will be instantiated for other types and logics as well.
  7006 
  7007 * The simplifier now accepts rewrite rules with flexible heads, eg
  7008      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7009   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7010   matching.
  7011 
  7012 
  7013 *** General ***
  7014 
  7015 * New Isabelle/Isar subsystem provides an alternative to traditional
  7016 tactical theorem proving; together with the ProofGeneral/isar user
  7017 interface it offers an interactive environment for developing human
  7018 readable proof documents (Isar == Intelligible semi-automated
  7019 reasoning); for further information see isatool doc isar-ref,
  7020 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7021 
  7022 * improved and simplified presentation of theories: better HTML markup
  7023 (including colors), graph views in several sizes; isatool usedir now
  7024 provides a proper interface for user theories (via -P option); actual
  7025 document preparation based on (PDF)LaTeX is available as well (for
  7026 new-style theories only); see isatool doc system for more information;
  7027 
  7028 * native support for Proof General, both for classic Isabelle and
  7029 Isabelle/Isar;
  7030 
  7031 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7032 using the graph browser tool;
  7033 
  7034 * Isabelle manuals now also available as PDF;
  7035 
  7036 * theory loader rewritten from scratch (may not be fully
  7037 bug-compatible); old loadpath variable has been replaced by show_path,
  7038 add_path, del_path, reset_path functions; new operations such as
  7039 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7040 isatool doc ref);
  7041 
  7042 * improved isatool install: option -k creates KDE application icon,
  7043 option -p DIR installs standalone binaries;
  7044 
  7045 * added ML_PLATFORM setting (useful for cross-platform installations);
  7046 more robust handling of platform specific ML images for SML/NJ;
  7047 
  7048 * the settings environment is now statically scoped, i.e. it is never
  7049 created again in sub-processes invoked from isabelle, isatool, or
  7050 Isabelle;
  7051 
  7052 * path element specification '~~' refers to '$ISABELLE_HOME';
  7053 
  7054 * in locales, the "assumes" and "defines" parts may be omitted if
  7055 empty;
  7056 
  7057 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7058 long arrows);
  7059 
  7060 * new print_mode "HTML";
  7061 
  7062 * new flag show_tags controls display of tags of theorems (which are
  7063 basically just comments that may be attached by some tools);
  7064 
  7065 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7066 mode and goal output format:
  7067 
  7068 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7069 244c244
  7070 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7071 ---
  7072 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7073 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7074 181c181
  7075 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7076 ---
  7077 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7078 
  7079 * function bind_thms stores lists of theorems (cf. bind_thm);
  7080 
  7081 * new shorthand tactics ftac, eatac, datac, fatac;
  7082 
  7083 * qed (and friends) now accept "" as result name; in that case the
  7084 theorem is not stored, but proper checks and presentation of the
  7085 result still apply;
  7086 
  7087 * theorem database now also indexes constants "Trueprop", "all",
  7088 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7089 
  7090 
  7091 *** HOL ***
  7092 
  7093 ** HOL arithmetic **
  7094 
  7095 * There are now decision procedures for linear arithmetic over nat and
  7096 int:
  7097 
  7098 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7099 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7100 are treated as atomic; subformulae not involving type `nat' or `int'
  7101 are ignored; quantified subformulae are ignored unless they are
  7102 positive universal or negative existential. The tactic has to be
  7103 invoked by hand and can be a little bit slow. In particular, the
  7104 running time is exponential in the number of occurrences of `min' and
  7105 `max', and `-' on `nat'.
  7106 
  7107 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7108 (negated) (in)equalities among the premises and the conclusion into
  7109 account (i.e. no compound formulae) and does not know about `min' and
  7110 `max', and `-' on `nat'. It is fast and is used automatically by the
  7111 simplifier.
  7112 
  7113 NB: At the moment, these decision procedures do not cope with mixed
  7114 nat/int formulae where the two parts interact, such as `m < n ==>
  7115 int(m) < int(n)'.
  7116 
  7117 * HOL/Numeral provides a generic theory of numerals (encoded
  7118 efficiently as bit strings); setup for types nat/int/real is in place;
  7119 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7120 int, existing theories and proof scripts may require a few additional
  7121 type constraints;
  7122 
  7123 * integer division and remainder can now be performed on constant
  7124 arguments;
  7125 
  7126 * many properties of integer multiplication, division and remainder
  7127 are now available;
  7128 
  7129 * An interface to the Stanford Validity Checker (SVC) is available through the
  7130 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7131 are proved automatically.  SVC must be installed separately, and its results
  7132 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7133 invocation of the underlying oracle).  For SVC see
  7134   http://verify.stanford.edu/SVC
  7135 
  7136 * IsaMakefile: the HOL-Real target now builds an actual image;
  7137 
  7138 
  7139 ** HOL misc **
  7140 
  7141 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7142 (in Isabelle/Isar) -- by Gertrud Bauer;
  7143 
  7144 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7145 analysis for assembly languages with subtypes;
  7146 
  7147 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7148 -- avoids syntactic ambiguities and treats state, transition, and
  7149 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7150 changed syntax and (many) tactics;
  7151 
  7152 * HOL/inductive: Now also handles more general introduction rules such
  7153   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7154   theorems are now maintained within the theory (maintained via the
  7155   "mono" attribute);
  7156 
  7157 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7158   (using function types) such as
  7159 
  7160   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7161 
  7162 * HOL/record: record_simproc (part of the default simpset) takes care
  7163 of selectors applied to updated records; record_split_tac is no longer
  7164 part of the default claset; update_defs may now be removed from the
  7165 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7166 
  7167   claset_ref () := claset() addSWrapper record_split_wrapper;
  7168   Delsimprocs [record_simproc]
  7169 
  7170 * HOL/typedef: fixed type inference for representing set; type
  7171 arguments now have to occur explicitly on the rhs as type constraints;
  7172 
  7173 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7174 names rather than an ML expression;
  7175 
  7176 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7177 supplied later.  Program schemes can be defined, such as
  7178     "While B C s = (if B s then While B C (C s) else s)"
  7179 where the well-founded relation can be chosen after B and C have been given.
  7180 
  7181 * HOL/List: the constructors of type list are now Nil and Cons;
  7182 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7183 course, ML tools referring to List.list.op # etc. have to be adapted;
  7184 
  7185 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7186 disabled by default; run isabelle with option -m HOL to get back to
  7187 the original Gordon/HOL-style output;
  7188 
  7189 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7190 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7191 
  7192 * HOL basic syntax simplified (more orthogonal): all variants of
  7193 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7194 Eps operator is provided as well: "SOME x. P[x]";
  7195 
  7196 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7197 
  7198 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7199 thus available for user theories;
  7200 
  7201 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7202 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7203 time;
  7204 
  7205 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7206 several times and then mp;
  7207 
  7208 
  7209 *** LK ***
  7210 
  7211 * the notation <<...>> is now available as a notation for sequences of
  7212 formulas;
  7213 
  7214 * the simplifier is now installed
  7215 
  7216 * the axiom system has been generalized (thanks to Soren Heilmann)
  7217 
  7218 * the classical reasoner now has a default rule database
  7219 
  7220 
  7221 *** ZF ***
  7222 
  7223 * new primrec section allows primitive recursive functions to be given
  7224 directly (as in HOL) over datatypes and the natural numbers;
  7225 
  7226 * new tactics induct_tac and exhaust_tac for induction (or case
  7227 analysis) over datatypes and the natural numbers;
  7228 
  7229 * the datatype declaration of type T now defines the recursor T_rec;
  7230 
  7231 * simplification automatically does freeness reasoning for datatype
  7232 constructors;
  7233 
  7234 * automatic type-inference, with AddTCs command to insert new
  7235 type-checking rules;
  7236 
  7237 * datatype introduction rules are now added as Safe Introduction rules
  7238 to the claset;
  7239 
  7240 * the syntax "if P then x else y" is now available in addition to
  7241 if(P,x,y);
  7242 
  7243 
  7244 *** Internal programming interfaces ***
  7245 
  7246 * tuned simplifier trace output; new flag debug_simp;
  7247 
  7248 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7249 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7250 
  7251 * AxClass.axclass_tac lost the theory argument;
  7252 
  7253 * tuned current_goals_markers semantics: begin / end goal avoids
  7254 printing empty lines;
  7255 
  7256 * removed prs and prs_fn hook, which was broken because it did not
  7257 include \n in its semantics, forcing writeln to add one
  7258 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7259 string -> unit if you really want to output text without newline;
  7260 
  7261 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7262 plain output, interface builders may have to enable 'isabelle_font'
  7263 mode to get Isabelle font glyphs as before;
  7264 
  7265 * refined token_translation interface; INCOMPATIBILITY: output length
  7266 now of type real instead of int;
  7267 
  7268 * theory loader actions may be traced via new ThyInfo.add_hook
  7269 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7270 your own database of information attached to *whole* theories -- as
  7271 opposed to intra-theory data slots offered via TheoryDataFun;
  7272 
  7273 * proper handling of dangling sort hypotheses (at last!);
  7274 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7275 extra sort hypotheses that can be witnessed from the type signature;
  7276 the force_strip_shyps flag is gone, any remaining shyps are simply
  7277 left in the theorem (with a warning issued by strip_shyps_warning);
  7278 
  7279 
  7280 
  7281 New in Isabelle98-1 (October 1998)
  7282 ----------------------------------
  7283 
  7284 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7285 
  7286 * several changes of automated proof tools;
  7287 
  7288 * HOL: major changes to the inductive and datatype packages, including
  7289 some minor incompatibilities of theory syntax;
  7290 
  7291 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7292 called `inj_on';
  7293 
  7294 * HOL: removed duplicate thms in Arith:
  7295   less_imp_add_less  should be replaced by  trans_less_add1
  7296   le_imp_add_le      should be replaced by  trans_le_add1
  7297 
  7298 * HOL: unary minus is now overloaded (new type constraints may be
  7299 required);
  7300 
  7301 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7302 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7303 now taken as an integer constant.
  7304 
  7305 * Pure: ML function 'theory_of' renamed to 'theory';
  7306 
  7307 
  7308 *** Proof tools ***
  7309 
  7310 * Simplifier:
  7311   1. Asm_full_simp_tac is now more aggressive.
  7312      1. It will sometimes reorient premises if that increases their power to
  7313         simplify.
  7314      2. It does no longer proceed strictly from left to right but may also
  7315         rotate premises to achieve further simplification.
  7316      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7317      old Asm_full_simp_tac in that it does not rotate premises.
  7318   2. The simplifier now knows a little bit about nat-arithmetic.
  7319 
  7320 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7321 allows for selected deletion of wrappers, by introduction of names for
  7322 wrapper functionals.  This implies that addbefore, addSbefore,
  7323 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7324 and that adding two tactics with the same name overwrites the first
  7325 one (emitting a warning).
  7326   type wrapper = (int -> tactic) -> (int -> tactic)
  7327   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7328   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7329   delWrapper, delSWrapper: claset *  string            -> claset
  7330   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7331 
  7332 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7333 semantics; addbefore now affects only the unsafe part of step_tac
  7334 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7335 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7336 by Force_tac;
  7337 
  7338 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7339 compWrapper; added safe wrapper (and access functions for it);
  7340 
  7341 * HOL/split_all_tac is now much faster and fails if there is nothing
  7342 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7343 and the names of the automatically generated variables have changed.
  7344 split_all_tac has moved within claset() from unsafe wrappers to safe
  7345 wrappers, which means that !!-bound variables are split much more
  7346 aggressively, and safe_tac and clarify_tac now split such variables.
  7347 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7348 Note: the same holds for record_split_tac, which does the job of
  7349 split_all_tac for record fields.
  7350 
  7351 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7352 permanently to the default simpset using Addsplits just like
  7353 Addsimps. They can be removed via Delsplits just like
  7354 Delsimps. Lower-case versions are also available.
  7355 
  7356 * HOL/Simplifier: The rule split_if is now part of the default
  7357 simpset. This means that the simplifier will eliminate all occurrences
  7358 of if-then-else in the conclusion of a goal. To prevent this, you can
  7359 either remove split_if completely from the default simpset by
  7360 `Delsplits [split_if]' or remove it in a specific call of the
  7361 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7362 other case splitting rules to/from the default simpset: every datatype
  7363 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7364 t is the name of the datatype).
  7365 
  7366 * Classical reasoner / Simplifier combination: new force_tac (and
  7367 derivatives Force_tac, force) combines rewriting and classical
  7368 reasoning (and whatever other tools) similarly to auto_tac, but is
  7369 aimed to solve the given subgoal completely.
  7370 
  7371 
  7372 *** General ***
  7373 
  7374 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7375 and `goalw': the theory is no longer needed as an explicit argument -
  7376 the current theory context is used; assumptions are no longer returned
  7377 at the ML-level unless one of them starts with ==> or !!; it is
  7378 recommended to convert to these new commands using isatool fixgoal
  7379 (backup your sources first!);
  7380 
  7381 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7382 the current theory context, and 'theory' to lookup stored theories;
  7383 
  7384 * new theory section 'locale' for declaring constants, assumptions and
  7385 definitions that have local scope;
  7386 
  7387 * new theory section 'nonterminals' for purely syntactic types;
  7388 
  7389 * new theory section 'setup' for generic ML setup functions
  7390 (e.g. package initialization);
  7391 
  7392 * the distribution now includes Isabelle icons: see
  7393 lib/logo/isabelle-{small,tiny}.xpm;
  7394 
  7395 * isatool install - install binaries with absolute references to
  7396 ISABELLE_HOME/bin;
  7397 
  7398 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7399 
  7400 * print mode 'emacs' reserved for Isamode;
  7401 
  7402 * support multiple print (ast) translations per constant name;
  7403 
  7404 * theorems involving oracles are now printed with a suffixed [!];
  7405 
  7406 
  7407 *** HOL ***
  7408 
  7409 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7410 
  7411 * HOL/inductive package reorganized and improved: now supports mutual
  7412 definitions such as
  7413 
  7414   inductive EVEN ODD
  7415     intrs
  7416       null "0 : EVEN"
  7417       oddI "n : EVEN ==> Suc n : ODD"
  7418       evenI "n : ODD ==> Suc n : EVEN"
  7419 
  7420 new theorem list "elims" contains an elimination rule for each of the
  7421 recursive sets; inductive definitions now handle disjunctive premises
  7422 correctly (also ZF);
  7423 
  7424 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7425 "mutual_induct" no longer exists - the induction rule is always
  7426 contained in "induct";
  7427 
  7428 
  7429 * HOL/datatype package re-implemented and greatly improved: now
  7430 supports mutually recursive datatypes such as
  7431 
  7432   datatype
  7433     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7434             | SUM ('a aexp) ('a aexp)
  7435             | DIFF ('a aexp) ('a aexp)
  7436             | NUM 'a
  7437   and
  7438     'a bexp = LESS ('a aexp) ('a aexp)
  7439             | AND ('a bexp) ('a bexp)
  7440             | OR ('a bexp) ('a bexp)
  7441 
  7442 as well as indirectly recursive datatypes such as
  7443 
  7444   datatype
  7445     ('a, 'b) term = Var 'a
  7446                   | App 'b ((('a, 'b) term) list)
  7447 
  7448 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7449 induction on mutually / indirectly recursive datatypes.
  7450 
  7451 Primrec equations are now stored in theory and can be accessed via
  7452 <function_name>.simps.
  7453 
  7454 INCOMPATIBILITIES:
  7455 
  7456   - Theories using datatypes must now have theory Datatype as an
  7457     ancestor.
  7458   - The specific <typename>.induct_tac no longer exists - use the
  7459     generic induct_tac instead.
  7460   - natE has been renamed to nat.exhaust - use exhaust_tac
  7461     instead of res_inst_tac ... natE. Note that the variable
  7462     names in nat.exhaust differ from the names in natE, this
  7463     may cause some "fragile" proofs to fail.
  7464   - The theorems split_<typename>_case and split_<typename>_case_asm
  7465     have been renamed to <typename>.split and <typename>.split_asm.
  7466   - Since default sorts of type variables are now handled correctly,
  7467     some datatype definitions may have to be annotated with explicit
  7468     sort constraints.
  7469   - Primrec definitions no longer require function name and type
  7470     of recursive argument.
  7471 
  7472 Consider using isatool fixdatatype to adapt your theories and proof
  7473 scripts to the new package (backup your sources first!).
  7474 
  7475 
  7476 * HOL/record package: considerably improved implementation; now
  7477 includes concrete syntax for record types, terms, updates; theorems
  7478 for surjective pairing and splitting !!-bound record variables; proof
  7479 support is as follows:
  7480 
  7481   1) standard conversions (selectors or updates applied to record
  7482 constructor terms) are part of the standard simpset;
  7483 
  7484   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7485 made part of standard simpset and claset via addIffs;
  7486 
  7487   3) a tactic for record field splitting (record_split_tac) is part of
  7488 the standard claset (addSWrapper);
  7489 
  7490 To get a better idea about these rules you may retrieve them via
  7491 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7492 the name of your record type.
  7493 
  7494 The split tactic 3) conceptually simplifies by the following rule:
  7495 
  7496   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7497 
  7498 Thus any record variable that is bound by meta-all will automatically
  7499 blow up into some record constructor term, consequently the
  7500 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7501 solve record problems automatically.
  7502 
  7503 
  7504 * reorganized the main HOL image: HOL/Integ and String loaded by
  7505 default; theory Main includes everything;
  7506 
  7507 * automatic simplification of integer sums and comparisons, using cancellation;
  7508 
  7509 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7510 
  7511 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7512 
  7513 * many new identities for unions, intersections, set difference, etc.;
  7514 
  7515 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7516 called split_if, split_split, split_sum_case and split_nat_case (to go
  7517 with add/delsplits);
  7518 
  7519 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7520 (?x::unit) = (); this is made part of the default simpset, which COULD
  7521 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7522 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7523 unit_abs_eta_conv is added in order to counter the effect of
  7524 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7525 %u.f();
  7526 
  7527 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7528 makes more sense);
  7529 
  7530 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7531   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7532   disjointness reasoning but breaking a few old proofs.
  7533 
  7534 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7535 to 'converse' from 'inverse' (for compatibility with ZF and some
  7536 literature);
  7537 
  7538 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7539 the well-founded relation;
  7540 
  7541 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7542     Compl A.  The "Compl" syntax remains available as input syntax for this
  7543     release ONLY.
  7544 
  7545 * HOL/Update: new theory of function updates:
  7546     f(a:=b) == %x. if x=a then b else f x
  7547 may also be iterated as in f(a:=b,c:=d,...);
  7548 
  7549 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7550 
  7551 * HOL/List:
  7552   - new function list_update written xs[i:=v] that updates the i-th
  7553     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7554   - new function `upt' written [i..j(] which generates the list
  7555     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7556     bound write [i..j], which is a shorthand for [i..j+1(].
  7557   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7558 
  7559 * HOL/Arith:
  7560   - removed 'pred' (predecessor) function;
  7561   - generalized some theorems about n-1;
  7562   - many new laws about "div" and "mod";
  7563   - new laws about greatest common divisors (see theory ex/Primes);
  7564 
  7565 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7566 instead of "inverse";
  7567 
  7568 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7569   of the multiset ordering;
  7570 
  7571 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7572   (not included by default);
  7573 
  7574 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7575 
  7576 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7577   programs, i.e. different program variables may have different types.
  7578 
  7579 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7580   [previously, this check worked only if the rewrite rule was unconditional]
  7581   Now rew can involve either definitions or equalities (either == or =).
  7582 
  7583 
  7584 *** ZF ***
  7585 
  7586 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7587   only the theorems proved on ZF.ML;
  7588 
  7589 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7590   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7591   disjointness reasoning but breaking a few old proofs.
  7592 
  7593 * ZF/Update: new theory of function updates
  7594     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7595   may also be iterated as in f(a:=b,c:=d,...);
  7596 
  7597 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7598 
  7599 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7600   [previously, this check worked only if the rewrite rule was unconditional]
  7601   Now rew can involve either definitions or equalities (either == or =).
  7602 
  7603 * case_tac provided for compatibility with HOL
  7604     (like the old excluded_middle_tac, but with subgoals swapped)
  7605 
  7606 
  7607 *** Internal programming interfaces ***
  7608 
  7609 * Pure: several new basic modules made available for general use, see
  7610 also src/Pure/README;
  7611 
  7612 * improved the theory data mechanism to support encapsulation (data
  7613 kind name replaced by private Object.kind, acting as authorization
  7614 key); new type-safe user interface via functor TheoryDataFun; generic
  7615 print_data function becomes basically useless;
  7616 
  7617 * removed global_names compatibility flag -- all theory declarations
  7618 are qualified by default;
  7619 
  7620 * module Pure/Syntax now offers quote / antiquote translation
  7621 functions (useful for Hoare logic etc. with implicit dependencies);
  7622 see HOL/ex/Antiquote for an example use;
  7623 
  7624 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7625 cterm -> thm;
  7626 
  7627 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7628 subgoal;
  7629 
  7630 * Display.print_goals function moved to Locale.print_goals;
  7631 
  7632 * standard print function for goals supports current_goals_markers
  7633 variable for marking begin of proof, end of proof, start of goal; the
  7634 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7635 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7636 for example;
  7637 
  7638 
  7639 
  7640 New in Isabelle98 (January 1998)
  7641 --------------------------------
  7642 
  7643 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7644 
  7645 * changed lexical syntax of terms / types: dots made part of long
  7646 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7647 
  7648 * simpset (and claset) reference variable replaced by functions
  7649 simpset / simpset_ref;
  7650 
  7651 * no longer supports theory aliases (via merge) and non-trivial
  7652 implicit merge of thms' signatures;
  7653 
  7654 * most internal names of constants changed due to qualified names;
  7655 
  7656 * changed Pure/Sequence interface (see Pure/seq.ML);
  7657 
  7658 
  7659 *** General Changes ***
  7660 
  7661 * hierachically structured name spaces (for consts, types, axms, thms
  7662 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7663 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7664 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7665 long_names for fully qualified output names; NOTE: ML programs
  7666 (special tactics, packages etc.) referring to internal names may have
  7667 to be adapted to cope with fully qualified names; in case of severe
  7668 backward campatibility problems try setting 'global_names' at compile
  7669 time to have enrything declared within a flat name space; one may also
  7670 fine tune name declarations in theories via the 'global' and 'local'
  7671 section;
  7672 
  7673 * reimplemented the implicit simpset and claset using the new anytype
  7674 data filed in signatures; references simpset:simpset ref etc. are
  7675 replaced by functions simpset:unit->simpset and
  7676 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7677 to patch your ML files accordingly;
  7678 
  7679 * HTML output now includes theory graph data for display with Java
  7680 applet or isatool browser; data generated automatically via isatool
  7681 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7682 
  7683 * defs may now be conditional; improved rewrite_goals_tac to handle
  7684 conditional equations;
  7685 
  7686 * defs now admits additional type arguments, using TYPE('a) syntax;
  7687 
  7688 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7689 creates a new theory node; implicit merge of thms' signatures is
  7690 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7691 transfer:theory->thm->thm in (rare) cases;
  7692 
  7693 * improved handling of draft signatures / theories; draft thms (and
  7694 ctyps, cterms) are automatically promoted to real ones;
  7695 
  7696 * slightly changed interfaces for oracles: admit many per theory, named
  7697 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7698 
  7699 * print_goals: optional output of const types (set show_consts and
  7700 show_types);
  7701 
  7702 * improved output of warnings (###) and errors (***);
  7703 
  7704 * subgoal_tac displays a warning if the new subgoal has type variables;
  7705 
  7706 * removed old README and Makefiles;
  7707 
  7708 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7709 
  7710 * removed obsolete init_pps and init_database;
  7711 
  7712 * deleted the obsolete tactical STATE, which was declared by
  7713     fun STATE tacfun st = tacfun st st;
  7714 
  7715 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7716 (which abbreviates $HOME);
  7717 
  7718 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7719 use isatool fixseq to adapt your ML programs (this works for fully
  7720 qualified references to the Sequence structure only!);
  7721 
  7722 * use_thy no longer requires writable current directory; it always
  7723 reloads .ML *and* .thy file, if either one is out of date;
  7724 
  7725 
  7726 *** Classical Reasoner ***
  7727 
  7728 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7729 tactics that use classical reasoning to simplify a subgoal without
  7730 splitting it into several subgoals;
  7731 
  7732 * Safe_tac: like safe_tac but uses the default claset;
  7733 
  7734 
  7735 *** Simplifier ***
  7736 
  7737 * added simplification meta rules:
  7738     (asm_)(full_)simplify: simpset -> thm -> thm;
  7739 
  7740 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7741 logics (again);
  7742 
  7743 * added prems argument to simplification procedures;
  7744 
  7745 * HOL, FOL, ZF: added infix function `addsplits':
  7746   instead of `<simpset> setloop (split_tac <thms>)'
  7747   you can simply write `<simpset> addsplits <thms>'
  7748 
  7749 
  7750 *** Syntax ***
  7751 
  7752 * TYPE('a) syntax for type reflection terms;
  7753 
  7754 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7755 
  7756 * pretty printer: changed order of mixfix annotation preference (again!);
  7757 
  7758 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7759 
  7760 
  7761 *** HOL ***
  7762 
  7763 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7764   with `addloop' of the simplifier to faciliate case splitting in premises.
  7765 
  7766 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7767 
  7768 * HOL/Auth: new protocol proofs including some for the Internet
  7769   protocol TLS;
  7770 
  7771 * HOL/Map: new theory of `maps' a la VDM;
  7772 
  7773 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7774 cancelling out common nat summands from =, <, <= (in)equalities, or
  7775 differences; simplification procedures nat_cancel_factor for
  7776 cancelling common factor from =, <, <= (in)equalities over natural
  7777 sums; nat_cancel contains both kinds of procedures, it is installed by
  7778 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7779 
  7780 * HOL/simplifier: terms of the form
  7781   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7782   are rewritten to
  7783   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7784   and those of the form
  7785   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7786   are rewritten to
  7787   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7788 
  7789 * HOL/datatype
  7790   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7791 
  7792   P(t_case f1 ... fn x) =
  7793      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7794         ...
  7795        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7796      )
  7797 
  7798   and a theorem `split_t_case_asm' of the form
  7799 
  7800   P(t_case f1 ... fn x) =
  7801     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7802         ...
  7803        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7804      )
  7805   which can be added to a simpset via `addsplits'. The existing theorems
  7806   expand_list_case and expand_option_case have been renamed to
  7807   split_list_case and split_option_case.
  7808 
  7809 * HOL/Arithmetic:
  7810   - `pred n' is automatically converted to `n-1'.
  7811     Users are strongly encouraged not to use `pred' any longer,
  7812     because it will disappear altogether at some point.
  7813   - Users are strongly encouraged to write "0 < n" rather than
  7814     "n ~= 0". Theorems and proof tools have been modified towards this
  7815     `standard'.
  7816 
  7817 * HOL/Lists:
  7818   the function "set_of_list" has been renamed "set" (and its theorems too);
  7819   the function "nth" now takes its arguments in the reverse order and
  7820   has acquired the infix notation "!" as in "xs!n".
  7821 
  7822 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7823 
  7824 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7825   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7826 
  7827 * HOL/record: extensible records with schematic structural subtyping
  7828 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7829 still lacks various theorems and concrete record syntax;
  7830 
  7831 
  7832 *** HOLCF ***
  7833 
  7834 * removed "axioms" and "generated by" sections;
  7835 
  7836 * replaced "ops" section by extended "consts" section, which is capable of
  7837   handling the continuous function space "->" directly;
  7838 
  7839 * domain package:
  7840   . proves theorems immediately and stores them in the theory,
  7841   . creates hierachical name space,
  7842   . now uses normal mixfix annotations (instead of cinfix...),
  7843   . minor changes to some names and values (for consistency),
  7844   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7845   . separator between mutual domain defs: changed "," to "and",
  7846   . improved handling of sort constraints;  now they have to
  7847     appear on the left-hand side of the equations only;
  7848 
  7849 * fixed LAM <x,y,zs>.b syntax;
  7850 
  7851 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7852 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7853 
  7854 
  7855 *** FOL and ZF ***
  7856 
  7857 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7858   with `addloop' of the simplifier to faciliate case splitting in premises.
  7859 
  7860 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7861 in HOL, they strip ALL and --> from proved theorems;
  7862 
  7863 
  7864 
  7865 New in Isabelle94-8 (May 1997)
  7866 ------------------------------
  7867 
  7868 *** General Changes ***
  7869 
  7870 * new utilities to build / run / maintain Isabelle etc. (in parts
  7871 still somewhat experimental); old Makefiles etc. still functional;
  7872 
  7873 * new 'Isabelle System Manual';
  7874 
  7875 * INSTALL text, together with ./configure and ./build scripts;
  7876 
  7877 * reimplemented type inference for greater efficiency, better error
  7878 messages and clean internal interface;
  7879 
  7880 * prlim command for dealing with lots of subgoals (an easier way of
  7881 setting goals_limit);
  7882 
  7883 
  7884 *** Syntax ***
  7885 
  7886 * supports alternative (named) syntax tables (parser and pretty
  7887 printer); internal interface is provided by add_modesyntax(_i);
  7888 
  7889 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7890 be used in conjunction with the Isabelle symbol font; uses the
  7891 "symbols" syntax table;
  7892 
  7893 * added token_translation interface (may translate name tokens in
  7894 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7895 the current print_mode); IMPORTANT: user print translation functions
  7896 are responsible for marking newly introduced bounds
  7897 (Syntax.mark_boundT);
  7898 
  7899 * token translations for modes "xterm" and "xterm_color" that display
  7900 names in bold, underline etc. or colors (which requires a color
  7901 version of xterm);
  7902 
  7903 * infixes may now be declared with names independent of their syntax;
  7904 
  7905 * added typed_print_translation (like print_translation, but may
  7906 access type of constant);
  7907 
  7908 
  7909 *** Classical Reasoner ***
  7910 
  7911 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7912 some limitations.  Blast_tac...
  7913   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7914   + ignores elimination rules that don't have the correct format
  7915         (the conclusion MUST be a formula variable)
  7916   + ignores types, which can make HOL proofs fail
  7917   + rules must not require higher-order unification, e.g. apply_type in ZF
  7918     [message "Function Var's argument not a bound variable" relates to this]
  7919   + its proof strategy is more general but can actually be slower
  7920 
  7921 * substitution with equality assumptions no longer permutes other
  7922 assumptions;
  7923 
  7924 * minor changes in semantics of addafter (now called addaltern); renamed
  7925 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7926 (and access functions for it);
  7927 
  7928 * improved combination of classical reasoner and simplifier:
  7929   + functions for handling clasimpsets
  7930   + improvement of addss: now the simplifier is called _after_ the
  7931     safe steps.
  7932   + safe variant of addss called addSss: uses safe simplifications
  7933     _during_ the safe steps. It is more complete as it allows multiple
  7934     instantiations of unknowns (e.g. with slow_tac).
  7935 
  7936 *** Simplifier ***
  7937 
  7938 * added interface for simplification procedures (functions that
  7939 produce *proven* rewrite rules on the fly, depending on current
  7940 redex);
  7941 
  7942 * ordering on terms as parameter (used for ordered rewriting);
  7943 
  7944 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7945 
  7946 * the solver is now split into a safe and an unsafe part.
  7947 This should be invisible for the normal user, except that the
  7948 functions setsolver and addsolver have been renamed to setSolver and
  7949 addSolver; added safe_asm_full_simp_tac;
  7950 
  7951 
  7952 *** HOL ***
  7953 
  7954 * a generic induction tactic `induct_tac' which works for all datatypes and
  7955 also for type `nat';
  7956 
  7957 * a generic case distinction tactic `exhaust_tac' which works for all
  7958 datatypes and also for type `nat';
  7959 
  7960 * each datatype comes with a function `size';
  7961 
  7962 * patterns in case expressions allow tuple patterns as arguments to
  7963 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7964 
  7965 * primrec now also works with type nat;
  7966 
  7967 * recdef: a new declaration form, allows general recursive functions to be
  7968 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7969 
  7970 * the constant for negation has been renamed from "not" to "Not" to
  7971 harmonize with FOL, ZF, LK, etc.;
  7972 
  7973 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7974 infinite lists;
  7975 
  7976 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7977 
  7978 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7979 problems in commutative rings, using axiomatic type classes for + and *;
  7980 
  7981 * more examples in HOL/MiniML and HOL/Auth;
  7982 
  7983 * more default rewrite rules for quantifiers, union/intersection;
  7984 
  7985 * a new constant `arbitrary == @x.False';
  7986 
  7987 * HOLCF/IOA replaces old HOL/IOA;
  7988 
  7989 * HOLCF changes: derived all rules and arities
  7990   + axiomatic type classes instead of classes
  7991   + typedef instead of faking type definitions
  7992   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7993   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7994   + eliminated the types void, one, tr
  7995   + use unit lift and bool lift (with translations) instead of one and tr
  7996   + eliminated blift from Lift3.thy (use Def instead of blift)
  7997   all eliminated rules are derived as theorems --> no visible changes ;
  7998 
  7999 
  8000 *** ZF ***
  8001 
  8002 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8003 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8004 as ZF_cs addSIs [equalityI];
  8005 
  8006 
  8007 
  8008 New in Isabelle94-7 (November 96)
  8009 ---------------------------------
  8010 
  8011 * allowing negative levels (as offsets) in prlev and choplev;
  8012 
  8013 * super-linear speedup for large simplifications;
  8014 
  8015 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8016 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8017 FAIL); can suppress it using the command Delsimps (ex_simps @
  8018 all_simps); De Morgan laws are also now included, by default;
  8019 
  8020 * improved printing of ==>  :  ~:
  8021 
  8022 * new object-logic "Sequents" adds linear logic, while replacing LK
  8023 and Modal (thanks to Sara Kalvala);
  8024 
  8025 * HOL/Auth: correctness proofs for authentication protocols;
  8026 
  8027 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8028 examples on HOL/Auth);
  8029 
  8030 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8031 the rewriter and classical reasoner simultaneously;
  8032 
  8033 * function uresult no longer returns theorems in "standard" format;
  8034 regain previous version by: val uresult = standard o uresult;
  8035 
  8036 
  8037 
  8038 New in Isabelle94-6
  8039 -------------------
  8040 
  8041 * oracles -- these establish an interface between Isabelle and trusted
  8042 external reasoners, which may deliver results as theorems;
  8043 
  8044 * proof objects (in particular record all uses of oracles);
  8045 
  8046 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8047 
  8048 * "constdefs" section in theory files;
  8049 
  8050 * "primrec" section (HOL) no longer requires names;
  8051 
  8052 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8053 
  8054 
  8055 
  8056 New in Isabelle94-5
  8057 -------------------
  8058 
  8059 * reduced space requirements;
  8060 
  8061 * automatic HTML generation from theories;
  8062 
  8063 * theory files no longer require "..." (quotes) around most types;
  8064 
  8065 * new examples, including two proofs of the Church-Rosser theorem;
  8066 
  8067 * non-curried (1994) version of HOL is no longer distributed;
  8068 
  8069 
  8070 
  8071 New in Isabelle94-4
  8072 -------------------
  8073 
  8074 * greatly reduced space requirements;
  8075 
  8076 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8077 
  8078 * searchable theorem database (see the section "Retrieving theorems" on
  8079 page 8 of the Reference Manual);
  8080 
  8081 * new examples, including Grabczewski's monumental case study of the
  8082 Axiom of Choice;
  8083 
  8084 * The previous version of HOL renamed to Old_HOL;
  8085 
  8086 * The new version of HOL (previously called CHOL) uses a curried syntax
  8087 for functions.  Application looks like f a b instead of f(a,b);
  8088 
  8089 * Mutually recursive inductive definitions finally work in HOL;
  8090 
  8091 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8092 translates to the operator "split";
  8093 
  8094 
  8095 
  8096 New in Isabelle94-3
  8097 -------------------
  8098 
  8099 * new infix operator, addss, allowing the classical reasoner to
  8100 perform simplification at each step of its search.  Example:
  8101         fast_tac (cs addss ss)
  8102 
  8103 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8104 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8105 look like (a,b) instead of <a,b>;
  8106 
  8107 * PLEASE NOTE: CHOL will eventually replace HOL!
  8108 
  8109 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8110 It translates to the operator "split".  A new theory of integers is available;
  8111 
  8112 * In ZF, integer numerals now denote two's-complement binary integers.
  8113 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8114 
  8115 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8116 of the Axiom of Choice;
  8117 
  8118 
  8119 
  8120 New in Isabelle94-2
  8121 -------------------
  8122 
  8123 * Significantly faster resolution;
  8124 
  8125 * the different sections in a .thy file can now be mixed and repeated
  8126 freely;
  8127 
  8128 * Database of theorems for FOL, HOL and ZF.  New
  8129 commands including qed, qed_goal and bind_thm store theorems in the database.
  8130 
  8131 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8132 a given theory (thms_of), or find out what theory a theorem was proved in
  8133 (theory_of_thm);
  8134 
  8135 * Bugs fixed in the inductive definition and datatype packages;
  8136 
  8137 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8138 and HOL_dup_cs obsolete;
  8139 
  8140 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8141 have been removed;
  8142 
  8143 * Simpler definition of function space in ZF;
  8144 
  8145 * new results about cardinal and ordinal arithmetic in ZF;
  8146 
  8147 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8148 types;
  8149 
  8150 :mode=text:wrap=hard:maxLineLen=72: