NEWS
author wenzelm
Tue, 22 Mar 2011 18:03:28 +0100
changeset 42937 160a630b2c7e
parent 42886 7b6e72a1b7dd
child 42938 3eba96ff3d3e
permissions -rw-r--r--
enable inner syntax source positions by default (controlled via configuration option);
disable source positions for HOLCF, due to special pattern translations;
     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 * Function package: discontinued option "tailrec".
    57 INCOMPATIBILITY. Use partial_function instead.
    58 
    59 
    60 *** Document preparation ***
    61 
    62 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    63 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    64 
    65 
    66 *** ML ***
    67 
    68 * Structure Timing provides various operations for timing; supersedes
    69 former start_timing/end_timing etc.
    70 
    71 * Path.print is the official way to show file-system paths to users
    72 (including quotes etc.).
    73 
    74 * Inner syntax: identifiers in parse trees of generic categories
    75 "logic", "aprop", "idt" etc. carry position information (disguised as
    76 type constraints).  Occasional INCOMPATIBILITY with non-compliant
    77 translations that choke on unexpected type constraints: use
    78 Syntax.strip_positions or Syntax.strip_positions_ast.  As last resort,
    79 reset the configuration option Syntax.positions, which is called
    80 "syntax_positions" in Isar attribute source.
    81 
    82 
    83 
    84 New in Isabelle2011 (January 2011)
    85 ----------------------------------
    86 
    87 *** General ***
    88 
    89 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
    90 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
    91 useful tooltips and hyperlinks produced from its static analysis.  The
    92 bundled component provides an executable Isabelle tool that can be run
    93 like this:
    94 
    95   Isabelle2011/bin/isabelle jedit
    96 
    97 * Significantly improved Isabelle/Isar implementation manual.
    98 
    99 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   100 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   101 while the default heap location within that directory lacks that extra
   102 suffix.  This isolates multiple Isabelle installations from each
   103 other, avoiding problems with old settings in new versions.
   104 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   105 
   106 * Source files are always encoded as UTF-8, instead of old-fashioned
   107 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   108 the following package declarations:
   109 
   110   \usepackage[utf8]{inputenc}
   111   \usepackage{textcomp}
   112 
   113 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   114 a Unicode character is treated as a single symbol, not a sequence of
   115 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   116 contain symbols without further backslash escapes, Unicode can now be
   117 used here as well.  Recall that Symbol.explode in ML provides a
   118 consistent view on symbols, while raw explode (or String.explode)
   119 merely give a byte-oriented representation.
   120 
   121 * Theory loader: source files are primarily located via the master
   122 directory of each theory node (where the .thy file itself resides).
   123 The global load path is still partially available as legacy feature.
   124 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   125 explicit paths, relatively to the theory.
   126 
   127 * Special treatment of ML file names has been discontinued.
   128 Historically, optional extensions .ML or .sml were added on demand --
   129 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   130 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   131 
   132 * Various options that affect pretty printing etc. are now properly
   133 handled within the context via configuration options, instead of
   134 unsynchronized references or print modes.  There are both ML Config.T
   135 entities and Isar declaration attributes to access these.
   136 
   137   ML (Config.T)                 Isar (attribute)
   138 
   139   eta_contract                  eta_contract
   140   show_brackets                 show_brackets
   141   show_sorts                    show_sorts
   142   show_types                    show_types
   143   show_question_marks           show_question_marks
   144   show_consts                   show_consts
   145   show_abbrevs                  show_abbrevs
   146 
   147   Syntax.ast_trace              syntax_ast_trace
   148   Syntax.ast_stat               syntax_ast_stat
   149   Syntax.ambiguity_level        syntax_ambiguity_level
   150 
   151   Goal_Display.goals_limit      goals_limit
   152   Goal_Display.show_main_goal   show_main_goal
   153 
   154   Method.rule_trace             rule_trace
   155 
   156   Thy_Output.display            thy_output_display
   157   Thy_Output.quotes             thy_output_quotes
   158   Thy_Output.indent             thy_output_indent
   159   Thy_Output.source             thy_output_source
   160   Thy_Output.break              thy_output_break
   161 
   162 Note that corresponding "..._default" references in ML may only be
   163 changed globally at the ROOT session setup, but *not* within a theory.
   164 The option "show_abbrevs" supersedes the former print mode
   165 "no_abbrevs" with inverted meaning.
   166 
   167 * More systematic naming of some configuration options.
   168 INCOMPATIBILITY.
   169 
   170   trace_simp  ~>  simp_trace
   171   debug_simp  ~>  simp_debug
   172 
   173 * Support for real valued configuration options, using simplistic
   174 floating-point notation that coincides with the inner syntax for
   175 float_token.
   176 
   177 * Support for real valued preferences (with approximative PGIP type):
   178 front-ends need to accept "pgint" values in float notation.
   179 INCOMPATIBILITY.
   180 
   181 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   182 DejaVu Sans.
   183 
   184 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   185 
   186 
   187 *** Pure ***
   188 
   189 * Command 'type_synonym' (with single argument) replaces somewhat
   190 outdated 'types', which is still available as legacy feature for some
   191 time.
   192 
   193 * Command 'nonterminal' (with 'and' separated list of arguments)
   194 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   195 
   196 * Command 'notepad' replaces former 'example_proof' for
   197 experimentation in Isar without any result.  INCOMPATIBILITY.
   198 
   199 * Locale interpretation commands 'interpret' and 'sublocale' accept
   200 lists of equations to map definitions in a locale to appropriate
   201 entities in the context of the interpretation.  The 'interpretation'
   202 command already provided this functionality.
   203 
   204 * Diagnostic command 'print_dependencies' prints the locale instances
   205 that would be activated if the specified expression was interpreted in
   206 the current context.  Variant "print_dependencies!" assumes a context
   207 without interpretations.
   208 
   209 * Diagnostic command 'print_interps' prints interpretations in proofs
   210 in addition to interpretations in theories.
   211 
   212 * Discontinued obsolete 'global' and 'local' commands to manipulate
   213 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   214 Sign.root_path and Sign.local_path may be applied directly where this
   215 feature is still required for historical reasons.
   216 
   217 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   218 'definition' instead.
   219 
   220 * The "prems" fact, which refers to the accidental collection of
   221 foundational premises in the context, is now explicitly marked as
   222 legacy feature and will be discontinued soon.  Consider using "assms"
   223 of the head statement or reference facts by explicit names.
   224 
   225 * Document antiquotations @{class} and @{type} print classes and type
   226 constructors.
   227 
   228 * Document antiquotation @{file} checks file/directory entries within
   229 the local file system.
   230 
   231 
   232 *** HOL ***
   233 
   234 * Coercive subtyping: functions can be declared as coercions and type
   235 inference will add them as necessary upon input of a term.  Theory
   236 Complex_Main declares real :: nat => real and real :: int => real as
   237 coercions. A coercion function f is declared like this:
   238 
   239   declare [[coercion f]]
   240 
   241 To lift coercions through type constructors (e.g. from nat => real to
   242 nat list => real list), map functions can be declared, e.g.
   243 
   244   declare [[coercion_map map]]
   245 
   246 Currently coercion inference is activated only in theories including
   247 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   248 the configuration option "coercion_enabled", e.g. it can be enabled in
   249 other theories like this:
   250 
   251   declare [[coercion_enabled]]
   252 
   253 * Command 'partial_function' provides basic support for recursive
   254 function definitions over complete partial orders.  Concrete instances
   255 are provided for i) the option type, ii) tail recursion on arbitrary
   256 types, and iii) the heap monad of Imperative_HOL.  See
   257 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   258 for examples.
   259 
   260 * Function package: f.psimps rules are no longer implicitly declared
   261 as [simp].  INCOMPATIBILITY.
   262 
   263 * Datatype package: theorems generated for executable equality (class
   264 "eq") carry proper names and are treated as default code equations.
   265 
   266 * Inductive package: now offers command 'inductive_simps' to
   267 automatically derive instantiated and simplified equations for
   268 inductive predicates, similar to 'inductive_cases'.
   269 
   270 * Command 'enriched_type' allows to register properties of the
   271 functorial structure of types.
   272 
   273 * Improved infrastructure for term evaluation using code generator
   274 techniques, in particular static evaluation conversions.
   275 
   276 * Code generator: Scala (2.8 or higher) has been added to the target
   277 languages.
   278 
   279 * Code generator: globbing constant expressions "*" and "Theory.*"
   280 have been replaced by the more idiomatic "_" and "Theory._".
   281 INCOMPATIBILITY.
   282 
   283 * Code generator: export_code without explicit file declaration prints
   284 to standard output.  INCOMPATIBILITY.
   285 
   286 * Code generator: do not print function definitions for case
   287 combinators any longer.
   288 
   289 * Code generator: simplification with rules determined with
   290 src/Tools/Code/code_simp.ML and method "code_simp".
   291 
   292 * Code generator for records: more idiomatic representation of record
   293 types.  Warning: records are not covered by ancient SML code
   294 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   295 rep_datatype declaration helps to succeed then:
   296 
   297   record 'a foo = ...
   298   ...
   299   rep_datatype foo_ext ...
   300 
   301 * Records: logical foundation type for records does not carry a
   302 '_type' suffix any longer (obsolete due to authentic syntax).
   303 INCOMPATIBILITY.
   304 
   305 * Quickcheck now by default uses exhaustive testing instead of random
   306 testing.  Random testing can be invoked by "quickcheck [random]",
   307 exhaustive testing by "quickcheck [exhaustive]".
   308 
   309 * Quickcheck instantiates polymorphic types with small finite
   310 datatypes by default. This enables a simple execution mechanism to
   311 handle quantifiers and function equality over the finite datatypes.
   312 
   313 * Quickcheck random generator has been renamed from "code" to
   314 "random".  INCOMPATIBILITY.
   315 
   316 * Quickcheck now has a configurable time limit which is set to 30
   317 seconds by default. This can be changed by adding [timeout = n] to the
   318 quickcheck command. The time limit for Auto Quickcheck is still set
   319 independently.
   320 
   321 * Quickcheck in locales considers interpretations of that locale for
   322 counter example search.
   323 
   324 * Sledgehammer:
   325   - Added "smt" and "remote_smt" provers based on the "smt" proof
   326     method. See the Sledgehammer manual for details ("isabelle doc
   327     sledgehammer").
   328   - Renamed commands:
   329     sledgehammer atp_info ~> sledgehammer running_provers
   330     sledgehammer atp_kill ~> sledgehammer kill_provers
   331     sledgehammer available_atps ~> sledgehammer available_provers
   332     INCOMPATIBILITY.
   333   - Renamed options:
   334     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   335     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   336     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   337     (and "ms" and "min" are no longer supported)
   338     INCOMPATIBILITY.
   339 
   340 * Nitpick:
   341   - Renamed options:
   342     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   343     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   344     INCOMPATIBILITY.
   345   - Added support for partial quotient types.
   346   - Added local versions of the "Nitpick.register_xxx" functions.
   347   - Added "whack" option.
   348   - Allow registration of quotient types as codatatypes.
   349   - Improved "merge_type_vars" option to merge more types.
   350   - Removed unsound "fast_descrs" option.
   351   - Added custom symmetry breaking for datatypes, making it possible to reach
   352     higher cardinalities.
   353   - Prevent the expansion of too large definitions.
   354 
   355 * Proof methods "metis" and "meson" now have configuration options
   356 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   357 to diagnose these tools. E.g.
   358 
   359     using [[metis_trace = true]]
   360 
   361 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   362 manually as command 'solve_direct'.
   363 
   364 * The default SMT solver Z3 must be enabled explicitly (due to
   365 licensing issues) by setting the environment variable
   366 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   367 commercial applications, the SMT solver CVC3 is provided as fall-back;
   368 changing the SMT solver is done via the configuration option
   369 "smt_solver".
   370 
   371 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   372 i.e. "remote_cvc3" and "remote_z3".
   373 
   374 * Added basic SMT support for datatypes, records, and typedefs using
   375 the oracle mode (no proofs).  Direct support of pairs has been dropped
   376 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   377 support for a similar behavior).  Minor INCOMPATIBILITY.
   378 
   379 * Changed SMT configuration options:
   380   - Renamed:
   381     z3_proofs ~> smt_oracle (with inverted meaning)
   382     z3_trace_assms ~> smt_trace_used_facts
   383     INCOMPATIBILITY.
   384   - Added:
   385     smt_verbose
   386     smt_random_seed
   387     smt_datatypes
   388     smt_infer_triggers
   389     smt_monomorph_limit
   390     cvc3_options
   391     remote_cvc3_options
   392     remote_z3_options
   393     yices_options
   394 
   395 * Boogie output files (.b2i files) need to be declared in the theory
   396 header.
   397 
   398 * Simplification procedure "list_to_set_comprehension" rewrites list
   399 comprehensions applied to List.set to set comprehensions.  Occasional
   400 INCOMPATIBILITY, may be deactivated like this:
   401 
   402   declare [[simproc del: list_to_set_comprehension]]
   403 
   404 * Removed old version of primrec package.  INCOMPATIBILITY.
   405 
   406 * Removed simplifier congruence rule of "prod_case", as has for long
   407 been the case with "split".  INCOMPATIBILITY.
   408 
   409 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   410 
   411 * Removed [split_format ... and ... and ...] version of
   412 [split_format].  Potential INCOMPATIBILITY.
   413 
   414 * Predicate "sorted" now defined inductively, with nice induction
   415 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   416 
   417 * Constant "contents" renamed to "the_elem", to free the generic name
   418 contents for other uses.  INCOMPATIBILITY.
   419 
   420 * Renamed class eq and constant eq (for code generation) to class
   421 equal and constant equal, plus renaming of related facts and various
   422 tuning.  INCOMPATIBILITY.
   423 
   424 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   425 
   426 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   427 INCOMPATIBILITY.
   428 
   429 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   430 avoid confusion with finite sets.  INCOMPATIBILITY.
   431 
   432 * Abandoned locales equiv, congruent and congruent2 for equivalence
   433 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   434 for congruent(2)).
   435 
   436 * Some previously unqualified names have been qualified:
   437 
   438   types
   439     bool ~> HOL.bool
   440     nat ~> Nat.nat
   441 
   442   constants
   443     Trueprop ~> HOL.Trueprop
   444     True ~> HOL.True
   445     False ~> HOL.False
   446     op & ~> HOL.conj
   447     op | ~> HOL.disj
   448     op --> ~> HOL.implies
   449     op = ~> HOL.eq
   450     Not ~> HOL.Not
   451     The ~> HOL.The
   452     All ~> HOL.All
   453     Ex ~> HOL.Ex
   454     Ex1 ~> HOL.Ex1
   455     Let ~> HOL.Let
   456     If ~> HOL.If
   457     Ball ~> Set.Ball
   458     Bex ~> Set.Bex
   459     Suc ~> Nat.Suc
   460     Pair ~> Product_Type.Pair
   461     fst ~> Product_Type.fst
   462     snd ~> Product_Type.snd
   463     curry ~> Product_Type.curry
   464     op : ~> Set.member
   465     Collect ~> Set.Collect
   466 
   467 INCOMPATIBILITY.
   468 
   469 * More canonical naming convention for some fundamental definitions:
   470 
   471     bot_bool_eq ~> bot_bool_def
   472     top_bool_eq ~> top_bool_def
   473     inf_bool_eq ~> inf_bool_def
   474     sup_bool_eq ~> sup_bool_def
   475     bot_fun_eq  ~> bot_fun_def
   476     top_fun_eq  ~> top_fun_def
   477     inf_fun_eq  ~> inf_fun_def
   478     sup_fun_eq  ~> sup_fun_def
   479 
   480 INCOMPATIBILITY.
   481 
   482 * More stylized fact names:
   483 
   484   expand_fun_eq ~> fun_eq_iff
   485   expand_set_eq ~> set_eq_iff
   486   set_ext       ~> set_eqI
   487   nat_number    ~> eval_nat_numeral
   488 
   489 INCOMPATIBILITY.
   490 
   491 * Refactoring of code-generation specific operations in theory List:
   492 
   493   constants
   494     null ~> List.null
   495 
   496   facts
   497     mem_iff ~> member_def
   498     null_empty ~> null_def
   499 
   500 INCOMPATIBILITY.  Note that these were not supposed to be used
   501 regularly unless for striking reasons; their main purpose was code
   502 generation.
   503 
   504 Various operations from the Haskell prelude are used for generating
   505 Haskell code.
   506 
   507 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   508 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   509 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   510 
   511 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   512 "*" and "+" respectively.  INCOMPATIBILITY.
   513 
   514 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   515 "Sum_Type.Plus" instead.
   516 
   517 * Constant "split" has been merged with constant "prod_case"; names of
   518 ML functions, facts etc. involving split have been retained so far,
   519 though.  INCOMPATIBILITY.
   520 
   521 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   522 instead.  INCOMPATIBILITY.
   523 
   524 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   525 INCOMPATIBILITY.
   526 
   527 * Former theory Library/Enum is now part of the HOL-Main image.
   528 INCOMPATIBILITY: all constants of the Enum theory now have to be
   529 referred to by its qualified name.
   530 
   531   enum    ~>  Enum.enum
   532   nlists  ~>  Enum.nlists
   533   product ~>  Enum.product
   534 
   535 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   536 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   537 INCOMPATIBILITY.
   538 
   539 * Theory Library/SetsAndFunctions has been split into
   540 Library/Function_Algebras and Library/Set_Algebras; canonical names
   541 for instance definitions for functions; various improvements.
   542 INCOMPATIBILITY.
   543 
   544 * Theory Library/Multiset provides stable quicksort implementation of
   545 sort_key.
   546 
   547 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   548 INCOMPATIBILITY.
   549 
   550 * Session Multivariate_Analysis: introduced a type class for euclidean
   551 space.  Most theorems are now stated in terms of euclidean spaces
   552 instead of finite cartesian products.
   553 
   554   types
   555     real ^ 'n ~>  'a::real_vector
   556               ~>  'a::euclidean_space
   557               ~>  'a::ordered_euclidean_space
   558         (depends on your needs)
   559 
   560   constants
   561      _ $ _        ~> _ $$ _
   562      \<chi> x. _  ~> \<chi>\<chi> x. _
   563      CARD('n)     ~> DIM('a)
   564 
   565 Also note that the indices are now natural numbers and not from some
   566 finite type. Finite cartesian products of euclidean spaces, products
   567 of euclidean spaces the real and complex numbers are instantiated to
   568 be euclidean_spaces.  INCOMPATIBILITY.
   569 
   570 * Session Probability: introduced pextreal as positive extended real
   571 numbers.  Use pextreal as value for measures.  Introduce the
   572 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   573 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   574 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   575 
   576 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   577 INCOMPATIBILITY.
   578 
   579 * Session SPARK (with image HOL-SPARK) provides commands to load and
   580 prove verification conditions generated by the SPARK Ada program
   581 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   582 
   583 
   584 *** HOL-Algebra ***
   585 
   586 * Theorems for additive ring operations (locale abelian_monoid and
   587 descendants) are generated by interpretation from their multiplicative
   588 counterparts.  Names (in particular theorem names) have the mandatory
   589 qualifier 'add'.  Previous theorem names are redeclared for
   590 compatibility.
   591 
   592 * Structure "int_ring" is now an abbreviation (previously a
   593 definition).  This fits more natural with advanced interpretations.
   594 
   595 
   596 *** HOLCF ***
   597 
   598 * The domain package now runs in definitional mode by default: The
   599 former command 'new_domain' is now called 'domain'.  To use the domain
   600 package in its original axiomatic mode, use 'domain (unsafe)'.
   601 INCOMPATIBILITY.
   602 
   603 * The new class "domain" is now the default sort.  Class "predomain"
   604 is an unpointed version of "domain". Theories can be updated by
   605 replacing sort annotations as shown below.  INCOMPATIBILITY.
   606 
   607   'a::type ~> 'a::countable
   608   'a::cpo  ~> 'a::predomain
   609   'a::pcpo ~> 'a::domain
   610 
   611 * The old type class "rep" has been superseded by class "domain".
   612 Accordingly, users of the definitional package must remove any
   613 "default_sort rep" declarations.  INCOMPATIBILITY.
   614 
   615 * The domain package (definitional mode) now supports unpointed
   616 predomain argument types, as long as they are marked 'lazy'. (Strict
   617 arguments must be in class "domain".) For example, the following
   618 domain definition now works:
   619 
   620   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   621 
   622 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   623 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   624 'a option, and 'a list.  Additionally, it configures fixrec and the
   625 domain package to work with these types.  For example:
   626 
   627   fixrec isInl :: "('a + 'b) u -> tr"
   628     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   629 
   630   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   631 
   632 * The "(permissive)" option of fixrec has been replaced with a
   633 per-equation "(unchecked)" option. See
   634 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   635 
   636 * The "bifinite" class no longer fixes a constant "approx"; the class
   637 now just asserts that such a function exists.  INCOMPATIBILITY.
   638 
   639 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   640 defines an embedding of type 'a defl into udom by default; instances
   641 of "bifinite" and "domain" classes are available in
   642 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   643 
   644 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   645 
   646 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   647 
   648 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   649 
   650 * The function "cprod_map" has been renamed to "prod_map".
   651 INCOMPATIBILITY.
   652 
   653 * The monadic bind operator on each powerdomain has new binder syntax
   654 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   655 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   656 
   657 * The infix syntax for binary union on each powerdomain has changed
   658 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   659 syntax.  INCOMPATIBILITY.
   660 
   661 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   662 still supported as an input translation.
   663 
   664 * Renamed some theorems (the original names are also still available).
   665 
   666   expand_fun_below   ~> fun_below_iff
   667   below_fun_ext      ~> fun_belowI
   668   expand_cfun_eq     ~> cfun_eq_iff
   669   ext_cfun           ~> cfun_eqI
   670   expand_cfun_below  ~> cfun_below_iff
   671   below_cfun_ext     ~> cfun_belowI
   672   cont2cont_Rep_CFun ~> cont2cont_APP
   673 
   674 * The Abs and Rep functions for various types have changed names.
   675 Related theorem names have also changed to match. INCOMPATIBILITY.
   676 
   677   Rep_CFun  ~> Rep_cfun
   678   Abs_CFun  ~> Abs_cfun
   679   Rep_Sprod ~> Rep_sprod
   680   Abs_Sprod ~> Abs_sprod
   681   Rep_Ssum  ~> Rep_ssum
   682   Abs_Ssum  ~> Abs_ssum
   683 
   684 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   685 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   686 
   687 * Various changes to bisimulation/coinduction with domain package:
   688 
   689   - Definitions of "bisim" constants no longer mention definedness.
   690   - With mutual recursion, "bisim" predicate is now curried.
   691   - With mutual recursion, each type gets a separate coind theorem.
   692   - Variable names in bisim_def and coinduct rules have changed.
   693 
   694 INCOMPATIBILITY.
   695 
   696 * Case combinators generated by the domain package for type "foo" are
   697 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   698 
   699 * Several theorems have been renamed to more accurately reflect the
   700 names of constants and types involved.  INCOMPATIBILITY.
   701 
   702   thelub_const    ~> lub_const
   703   lub_const       ~> is_lub_const
   704   thelubI         ~> lub_eqI
   705   is_lub_lub      ~> is_lubD2
   706   lubI            ~> is_lub_lub
   707   unique_lub      ~> is_lub_unique
   708   is_ub_lub       ~> is_lub_rangeD1
   709   lub_bin_chain   ~> is_lub_bin_chain
   710   lub_fun         ~> is_lub_fun
   711   thelub_fun      ~> lub_fun
   712   thelub_cfun     ~> lub_cfun
   713   thelub_Pair     ~> lub_Pair
   714   lub_cprod       ~> is_lub_prod
   715   thelub_cprod    ~> lub_prod
   716   minimal_cprod   ~> minimal_prod
   717   inst_cprod_pcpo ~> inst_prod_pcpo
   718   UU_I            ~> bottomI
   719   compact_UU      ~> compact_bottom
   720   deflation_UU    ~> deflation_bottom
   721   finite_deflation_UU ~> finite_deflation_bottom
   722 
   723 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   724 
   725   sq_ord_less_eq_trans ~> below_eq_trans
   726   sq_ord_eq_less_trans ~> eq_below_trans
   727   refl_less            ~> below_refl
   728   trans_less           ~> below_trans
   729   antisym_less         ~> below_antisym
   730   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   731   box_less             ~> box_below
   732   rev_trans_less       ~> rev_below_trans
   733   not_less2not_eq      ~> not_below2not_eq
   734   less_UU_iff          ~> below_UU_iff
   735   flat_less_iff        ~> flat_below_iff
   736   adm_less             ~> adm_below
   737   adm_not_less         ~> adm_not_below
   738   adm_compact_not_less ~> adm_compact_not_below
   739   less_fun_def         ~> below_fun_def
   740   expand_fun_less      ~> fun_below_iff
   741   less_fun_ext         ~> fun_belowI
   742   less_discr_def       ~> below_discr_def
   743   discr_less_eq        ~> discr_below_eq
   744   less_unit_def        ~> below_unit_def
   745   less_cprod_def       ~> below_prod_def
   746   prod_lessI           ~> prod_belowI
   747   Pair_less_iff        ~> Pair_below_iff
   748   fst_less_iff         ~> fst_below_iff
   749   snd_less_iff         ~> snd_below_iff
   750   expand_cfun_less     ~> cfun_below_iff
   751   less_cfun_ext        ~> cfun_belowI
   752   injection_less       ~> injection_below
   753   less_up_def          ~> below_up_def
   754   not_Iup_less         ~> not_Iup_below
   755   Iup_less             ~> Iup_below
   756   up_less              ~> up_below
   757   Def_inject_less_eq   ~> Def_below_Def
   758   Def_less_is_eq       ~> Def_below_iff
   759   spair_less_iff       ~> spair_below_iff
   760   less_sprod           ~> below_sprod
   761   spair_less           ~> spair_below
   762   sfst_less_iff        ~> sfst_below_iff
   763   ssnd_less_iff        ~> ssnd_below_iff
   764   fix_least_less       ~> fix_least_below
   765   dist_less_one        ~> dist_below_one
   766   less_ONE             ~> below_ONE
   767   ONE_less_iff         ~> ONE_below_iff
   768   less_sinlD           ~> below_sinlD
   769   less_sinrD           ~> below_sinrD
   770 
   771 
   772 *** FOL and ZF ***
   773 
   774 * All constant names are now qualified internally and use proper
   775 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   776 
   777 
   778 *** ML ***
   779 
   780 * Antiquotation @{assert} inlines a function bool -> unit that raises
   781 Fail if the argument is false.  Due to inlining the source position of
   782 failed assertions is included in the error output.
   783 
   784 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   785 text is in practice always evaluated with a stable theory checkpoint.
   786 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   787 
   788 * Antiquotation @{theory A} refers to theory A from the ancestry of
   789 the current context, not any accidental theory loader state as before.
   790 Potential INCOMPATIBILITY, subtle change in semantics.
   791 
   792 * Syntax.pretty_priority (default 0) configures the required priority
   793 of pretty-printed output and thus affects insertion of parentheses.
   794 
   795 * Syntax.default_root (default "any") configures the inner syntax
   796 category (nonterminal symbol) for parsing of terms.
   797 
   798 * Former exception Library.UnequalLengths now coincides with
   799 ListPair.UnequalLengths.
   800 
   801 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   802 main functionality is provided by structure Simplifier.
   803 
   804 * Renamed raw "explode" function to "raw_explode" to emphasize its
   805 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   806 almost all situations.
   807 
   808 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   809 See implementation manual for further details on exceptions in
   810 Isabelle/ML.
   811 
   812 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   813 meaning.
   814 
   815 * Renamed structure PureThy to Pure_Thy and moved most of its
   816 operations to structure Global_Theory, to emphasize that this is
   817 rarely-used global-only stuff.
   818 
   819 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   820 instead (or tracing for high-volume output).
   821 
   822 * Configuration option show_question_marks only affects regular pretty
   823 printing of types and terms, not raw Term.string_of_vname.
   824 
   825 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   826 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   827 @{thms} for most purposes.
   828 
   829 * ML structure Unsynchronized is never opened, not even in Isar
   830 interaction mode as before.  Old Unsynchronized.set etc. have been
   831 discontinued -- use plain := instead.  This should be *rare* anyway,
   832 since modern tools always work via official context data, notably
   833 configuration options.
   834 
   835 * Parallel and asynchronous execution requires special care concerning
   836 interrupts.  Structure Exn provides some convenience functions that
   837 avoid working directly with raw Interrupt.  User code must not absorb
   838 interrupts -- intermediate handling (for cleanup etc.) needs to be
   839 followed by re-raising of the original exception.  Another common
   840 source of mistakes are "handle _" patterns, which make the meaning of
   841 the program subject to physical effects of the environment.
   842 
   843 
   844 
   845 New in Isabelle2009-2 (June 2010)
   846 ---------------------------------
   847 
   848 *** General ***
   849 
   850 * Authentic syntax for *all* logical entities (type classes, type
   851 constructors, term constants): provides simple and robust
   852 correspondence between formal entities and concrete syntax.  Within
   853 the parse tree / AST representations, "constants" are decorated by
   854 their category (class, type, const) and spelled out explicitly with
   855 their full internal name.
   856 
   857 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   858 and translations (translation rules and translation functions in ML).
   859 Some hints on upgrading:
   860 
   861   - Many existing uses of 'syntax' and 'translations' can be replaced
   862     by more modern 'type_notation', 'notation' and 'abbreviation',
   863     which are independent of this issue.
   864 
   865   - 'translations' require markup within the AST; the term syntax
   866     provides the following special forms:
   867 
   868       CONST c   -- produces syntax version of constant c from context
   869       XCONST c  -- literally c, checked as constant from context
   870       c         -- literally c, if declared by 'syntax'
   871 
   872     Plain identifiers are treated as AST variables -- occasionally the
   873     system indicates accidental variables via the error "rhs contains
   874     extra variables".
   875 
   876     Type classes and type constructors are marked according to their
   877     concrete syntax.  Some old translations rules need to be written
   878     for the "type" category, using type constructor application
   879     instead of pseudo-term application of the default category
   880     "logic".
   881 
   882   - 'parse_translation' etc. in ML may use the following
   883     antiquotations:
   884 
   885       @{class_syntax c}   -- type class c within parse tree / AST
   886       @{term_syntax c}    -- type constructor c within parse tree / AST
   887       @{const_syntax c}   -- ML version of "CONST c" above
   888       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   889 
   890   - Literal types within 'typed_print_translations', i.e. those *not*
   891     represented as pseudo-terms are represented verbatim.  Use @{class
   892     c} or @{type_name c} here instead of the above syntax
   893     antiquotations.
   894 
   895 Note that old non-authentic syntax was based on unqualified base
   896 names, so all of the above "constant" names would coincide.  Recall
   897 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   898 diagnose syntax problems.
   899 
   900 * Type constructors admit general mixfix syntax, not just infix.
   901 
   902 * Concrete syntax may be attached to local entities without a proof
   903 body, too.  This works via regular mixfix annotations for 'fix',
   904 'def', 'obtain' etc. or via the explicit 'write' command, which is
   905 similar to the 'notation' command in theory specifications.
   906 
   907 * Discontinued unnamed infix syntax (legacy feature for many years) --
   908 need to specify constant name and syntax separately.  Internal ML
   909 datatype constructors have been renamed from InfixName to Infix etc.
   910 Minor INCOMPATIBILITY.
   911 
   912 * Schematic theorem statements need to be explicitly markup as such,
   913 via commands 'schematic_lemma', 'schematic_theorem',
   914 'schematic_corollary'.  Thus the relevance of the proof is made
   915 syntactically clear, which impacts performance in a parallel or
   916 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   917 
   918 * Use of cumulative prems via "!" in some proof methods has been
   919 discontinued (old legacy feature).
   920 
   921 * References 'trace_simp' and 'debug_simp' have been replaced by
   922 configuration options stored in the context. Enabling tracing (the
   923 case of debugging is similar) in proofs works via
   924 
   925   using [[trace_simp = true]]
   926 
   927 Tracing is then active for all invocations of the simplifier in
   928 subsequent goal refinement steps. Tracing may also still be enabled or
   929 disabled via the ProofGeneral settings menu.
   930 
   931 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   932 'hide_fact' replace the former 'hide' KIND command.  Minor
   933 INCOMPATIBILITY.
   934 
   935 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   936 more efficient than combinations with -q1 or -q2.
   937 
   938 
   939 *** Pure ***
   940 
   941 * Proofterms record type-class reasoning explicitly, using the
   942 "unconstrain" operation internally.  This eliminates all sort
   943 constraints from a theorem and proof, introducing explicit
   944 OFCLASS-premises.  On the proof term level, this operation is
   945 automatically applied at theorem boundaries, such that closed proofs
   946 are always free of sort constraints.  INCOMPATIBILITY for tools that
   947 inspect proof terms.
   948 
   949 * Local theory specifications may depend on extra type variables that
   950 are not present in the result type -- arguments TYPE('a) :: 'a itself
   951 are added internally.  For example:
   952 
   953   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   954 
   955 * Predicates of locales introduced by classes carry a mandatory
   956 "class" prefix.  INCOMPATIBILITY.
   957 
   958 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   959 
   960 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   961 'class' instead.
   962 
   963 * Command 'code_reflect' allows to incorporate generated ML code into
   964 runtime environment; replaces immature code_datatype antiquotation.
   965 INCOMPATIBILITY.
   966 
   967 * Code generator: simple concept for abstract datatypes obeying
   968 invariants.
   969 
   970 * Code generator: details of internal data cache have no impact on the
   971 user space functionality any longer.
   972 
   973 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   974 subgoals.  This is more appropriate for interpretations with 'where'.
   975 INCOMPATIBILITY.
   976 
   977 * Command 'example_proof' opens an empty proof body.  This allows to
   978 experiment with Isar, without producing any persistent result.
   979 
   980 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   981 within a local theory context, with explicit checking of the
   982 constructors involved (in contrast to the raw 'syntax' versions).
   983 
   984 * Commands 'types' and 'typedecl' now work within a local theory
   985 context -- without introducing dependencies on parameters or
   986 assumptions, which is not possible in Isabelle/Pure.
   987 
   988 * Command 'defaultsort' has been renamed to 'default_sort', it works
   989 within a local theory context.  Minor INCOMPATIBILITY.
   990 
   991 
   992 *** HOL ***
   993 
   994 * Command 'typedef' now works within a local theory context -- without
   995 introducing dependencies on parameters or assumptions, which is not
   996 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   997 contain multiple interpretations of local typedefs (with different
   998 non-emptiness proofs), even in a global theory context.
   999 
  1000 * New package for quotient types.  Commands 'quotient_type' and
  1001 'quotient_definition' may be used for defining types and constants by
  1002 quotient constructions.  An example is the type of integers created by
  1003 quotienting pairs of natural numbers:
  1004 
  1005   fun
  1006     intrel :: "(nat * nat) => (nat * nat) => bool"
  1007   where
  1008     "intrel (x, y) (u, v) = (x + v = u + y)"
  1009 
  1010   quotient_type int = "nat * nat" / intrel
  1011     by (auto simp add: equivp_def expand_fun_eq)
  1012 
  1013   quotient_definition
  1014     "0::int" is "(0::nat, 0::nat)"
  1015 
  1016 The method "lifting" can be used to lift of theorems from the
  1017 underlying "raw" type to the quotient type.  The example
  1018 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1019 construction and provides a reasoning infrastructure for finite sets.
  1020 
  1021 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1022 clash with new theory Quotient in Main HOL.
  1023 
  1024 * Moved the SMT binding into the main HOL session, eliminating
  1025 separate HOL-SMT session.
  1026 
  1027 * List membership infix mem operation is only an input abbreviation.
  1028 INCOMPATIBILITY.
  1029 
  1030 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1031 for future developements; former Library/Word.thy is still present in
  1032 the AFP entry RSAPPS.
  1033 
  1034 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1035 longer shadowed.  INCOMPATIBILITY.
  1036 
  1037 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1038 INCOMPATIBILITY.
  1039 
  1040 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1041 INCOMPATIBILITY.
  1042 
  1043 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1044 instead.  INCOMPATIBILITY.
  1045 
  1046 * Dropped several real-specific versions of lemmas about floor and
  1047 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1048 instead.  INCOMPATIBILITY.
  1049 
  1050   floor_number_of_eq         ~> floor_number_of
  1051   le_floor_eq_number_of      ~> number_of_le_floor
  1052   le_floor_eq_zero           ~> zero_le_floor
  1053   le_floor_eq_one            ~> one_le_floor
  1054   floor_less_eq_number_of    ~> floor_less_number_of
  1055   floor_less_eq_zero         ~> floor_less_zero
  1056   floor_less_eq_one          ~> floor_less_one
  1057   less_floor_eq_number_of    ~> number_of_less_floor
  1058   less_floor_eq_zero         ~> zero_less_floor
  1059   less_floor_eq_one          ~> one_less_floor
  1060   floor_le_eq_number_of      ~> floor_le_number_of
  1061   floor_le_eq_zero           ~> floor_le_zero
  1062   floor_le_eq_one            ~> floor_le_one
  1063   floor_subtract_number_of   ~> floor_diff_number_of
  1064   floor_subtract_one         ~> floor_diff_one
  1065   ceiling_number_of_eq       ~> ceiling_number_of
  1066   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1067   ceiling_le_zero_eq         ~> ceiling_le_zero
  1068   ceiling_le_eq_one          ~> ceiling_le_one
  1069   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1070   less_ceiling_eq_zero       ~> zero_less_ceiling
  1071   less_ceiling_eq_one        ~> one_less_ceiling
  1072   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1073   ceiling_less_eq_zero       ~> ceiling_less_zero
  1074   ceiling_less_eq_one        ~> ceiling_less_one
  1075   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1076   le_ceiling_eq_zero         ~> zero_le_ceiling
  1077   le_ceiling_eq_one          ~> one_le_ceiling
  1078   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1079   ceiling_subtract_one       ~> ceiling_diff_one
  1080 
  1081 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1082 application of the various fold combinators on finite sets.
  1083 
  1084 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1085 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1086 implementation.  INCOMPATIBILTY.
  1087 
  1088 * Theory Library/Coinductive_List has been removed -- superseded by
  1089 AFP/thys/Coinductive.
  1090 
  1091 * Theory PReal, including the type "preal" and related operations, has
  1092 been removed.  INCOMPATIBILITY.
  1093 
  1094 * Real: new development using Cauchy Sequences.
  1095 
  1096 * Split off theory "Big_Operators" containing setsum, setprod,
  1097 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1098 
  1099 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1100 "Int" etc.  INCOMPATIBILITY.
  1101 
  1102 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1103 
  1104 * New set of rules "ac_simps" provides combined assoc / commute
  1105 rewrites for all interpretations of the appropriate generic locales.
  1106 
  1107 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1108 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1109 appropriate and more consistent names suitable for name prefixes
  1110 within the HOL theories.  INCOMPATIBILITY.
  1111 
  1112 * Some generic constants have been put to appropriate theories:
  1113   - less_eq, less: Orderings
  1114   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1115   - inverse, divide: Rings
  1116 INCOMPATIBILITY.
  1117 
  1118 * More consistent naming of type classes involving orderings (and
  1119 lattices):
  1120 
  1121     lower_semilattice                   ~> semilattice_inf
  1122     upper_semilattice                   ~> semilattice_sup
  1123 
  1124     dense_linear_order                  ~> dense_linorder
  1125 
  1126     pordered_ab_group_add               ~> ordered_ab_group_add
  1127     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1128     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1129     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1130     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1131     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1132     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1133     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1134     pordered_comm_ring                  ~> ordered_comm_ring
  1135     pordered_comm_semiring              ~> ordered_comm_semiring
  1136     pordered_ring                       ~> ordered_ring
  1137     pordered_ring_abs                   ~> ordered_ring_abs
  1138     pordered_semiring                   ~> ordered_semiring
  1139 
  1140     ordered_ab_group_add                ~> linordered_ab_group_add
  1141     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1142     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1143     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1144     ordered_field                       ~> linordered_field
  1145     ordered_field_no_lb                 ~> linordered_field_no_lb
  1146     ordered_field_no_ub                 ~> linordered_field_no_ub
  1147     ordered_field_dense_linear_order    ~> dense_linordered_field
  1148     ordered_idom                        ~> linordered_idom
  1149     ordered_ring                        ~> linordered_ring
  1150     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1151     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1152     ordered_ring_strict                 ~> linordered_ring_strict
  1153     ordered_semidom                     ~> linordered_semidom
  1154     ordered_semiring                    ~> linordered_semiring
  1155     ordered_semiring_1                  ~> linordered_semiring_1
  1156     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1157     ordered_semiring_strict             ~> linordered_semiring_strict
  1158 
  1159   The following slightly odd type classes have been moved to a
  1160   separate theory Library/Lattice_Algebras:
  1161 
  1162     lordered_ab_group_add               ~> lattice_ab_group_add
  1163     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1164     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1165     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1166     lordered_ring                       ~> lattice_ring
  1167 
  1168 INCOMPATIBILITY.
  1169 
  1170 * Refined field classes:
  1171   - classes division_ring_inverse_zero, field_inverse_zero,
  1172     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1173     subsumes former division_by_zero class;
  1174   - numerous lemmas have been ported from field to division_ring.
  1175 INCOMPATIBILITY.
  1176 
  1177 * Refined algebra theorem collections:
  1178   - dropped theorem group group_simps, use algebra_simps instead;
  1179   - dropped theorem group ring_simps, use field_simps instead;
  1180   - proper theorem collection field_simps subsumes former theorem
  1181     groups field_eq_simps and field_simps;
  1182   - dropped lemma eq_minus_self_iff which is a duplicate for
  1183     equal_neg_zero.
  1184 INCOMPATIBILITY.
  1185 
  1186 * Theory Finite_Set and List: some lemmas have been generalized from
  1187 sets to lattices:
  1188 
  1189   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1190   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1191   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1192   union_Union_fold_union        ~> sup_Sup_fold_sup
  1193   Inter_fold_inter              ~> Inf_fold_inf
  1194   Union_fold_union              ~> Sup_fold_sup
  1195   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1196   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1197   INTER_fold_inter              ~> INFI_fold_inf
  1198   UNION_fold_union              ~> SUPR_fold_sup
  1199 
  1200 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1201 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1202 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1203 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1204 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1205 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1206 
  1207 * Reorganized theory Multiset: swapped notation of pointwise and
  1208 multiset order:
  1209 
  1210   - pointwise ordering is instance of class order with standard syntax
  1211     <= and <;
  1212   - multiset ordering has syntax <=# and <#; partial order properties
  1213     are provided by means of interpretation with prefix
  1214     multiset_order;
  1215   - less duplication, less historical organization of sections,
  1216     conversion from associations lists to multisets, rudimentary code
  1217     generation;
  1218   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1219     if needed.
  1220 
  1221 Renamed:
  1222 
  1223   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1224   multi_count_ext  ~>  multiset_ext
  1225   diff_union_inverse2  ~>  diff_union_cancelR
  1226 
  1227 INCOMPATIBILITY.
  1228 
  1229 * Theory Permutation: replaced local "remove" by List.remove1.
  1230 
  1231 * Code generation: ML and OCaml code is decorated with signatures.
  1232 
  1233 * Theory List: added transpose.
  1234 
  1235 * Library/Nat_Bijection.thy is a collection of bijective functions
  1236 between nat and other types, which supersedes the older libraries
  1237 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1238 
  1239   Constants:
  1240   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1241   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1242   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1243   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1244   Countable.pair_encode           ~> prod_encode
  1245   NatIso.prod2nat                 ~> prod_encode
  1246   NatIso.nat2prod                 ~> prod_decode
  1247   NatIso.sum2nat                  ~> sum_encode
  1248   NatIso.nat2sum                  ~> sum_decode
  1249   NatIso.list2nat                 ~> list_encode
  1250   NatIso.nat2list                 ~> list_decode
  1251   NatIso.set2nat                  ~> set_encode
  1252   NatIso.nat2set                  ~> set_decode
  1253 
  1254   Lemmas:
  1255   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1256   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1257   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1258   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1259   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1260   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1261   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1262   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1263   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1264   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1265   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1266   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1267   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1268 
  1269 * Sledgehammer:
  1270   - Renamed ATP commands:
  1271     atp_info     ~> sledgehammer running_atps
  1272     atp_kill     ~> sledgehammer kill_atps
  1273     atp_messages ~> sledgehammer messages
  1274     atp_minimize ~> sledgehammer minimize
  1275     print_atps   ~> sledgehammer available_atps
  1276     INCOMPATIBILITY.
  1277   - Added user's manual ("isabelle doc sledgehammer").
  1278   - Added option syntax and "sledgehammer_params" to customize
  1279     Sledgehammer's behavior.  See the manual for details.
  1280   - Modified the Isar proof reconstruction code so that it produces
  1281     direct proofs rather than proofs by contradiction.  (This feature
  1282     is still experimental.)
  1283   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1284     full-typed mode.
  1285   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1286 
  1287 * Nitpick:
  1288   - Added and implemented "binary_ints" and "bits" options.
  1289   - Added "std" option and implemented support for nonstandard models.
  1290   - Added and implemented "finitize" option to improve the precision
  1291     of infinite datatypes based on a monotonicity analysis.
  1292   - Added support for quotient types.
  1293   - Added support for "specification" and "ax_specification"
  1294     constructs.
  1295   - Added support for local definitions (for "function" and
  1296     "termination" proofs).
  1297   - Added support for term postprocessors.
  1298   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1299   - Improved efficiency of "destroy_constrs" optimization.
  1300   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1301     record getters.
  1302   - Fixed soundness bug related to higher-order constructors.
  1303   - Fixed soundness bug when "full_descrs" is enabled.
  1304   - Improved precision of set constructs.
  1305   - Added "atoms" option.
  1306   - Added cache to speed up repeated Kodkod invocations on the same
  1307     problems.
  1308   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1309     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1310     "SAT4J_Light".  INCOMPATIBILITY.
  1311   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1312     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1313   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1314 
  1315 * Method "induct" now takes instantiations of the form t, where t is not
  1316   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1317   If this is not intended, t has to be enclosed in parentheses.
  1318   By default, the equalities generated by definitional instantiations
  1319   are pre-simplified, which may cause parameters of inductive cases
  1320   to disappear, or may even delete some of the inductive cases.
  1321   Use "induct (no_simp)" instead of "induct" to restore the old
  1322   behaviour. The (no_simp) option is also understood by the "cases"
  1323   and "nominal_induct" methods, which now perform pre-simplification, too.
  1324   INCOMPATIBILITY.
  1325 
  1326 
  1327 *** HOLCF ***
  1328 
  1329 * Variable names in lemmas generated by the domain package have
  1330 changed; the naming scheme is now consistent with the HOL datatype
  1331 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1332 
  1333 * The domain package no longer defines the function "foo_copy" for
  1334 recursive domain "foo".  The reach lemma is now stated directly in
  1335 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1336 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1337 
  1338 * Most definedness lemmas generated by the domain package (previously
  1339 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1340 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1341 Proofs that used definedness lemmas as intro rules may break,
  1342 potential INCOMPATIBILITY.
  1343 
  1344 * Induction and casedist rules generated by the domain package now
  1345 declare proper case_names (one called "bottom", and one named for each
  1346 constructor).  INCOMPATIBILITY.
  1347 
  1348 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1349 rules are generated for each domain, INCOMPATIBILITY.
  1350 
  1351   foo_bar.reach       ~> foo.reach  bar.reach
  1352   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1353 
  1354 * Some lemmas generated by the domain package have been renamed for
  1355 consistency with the datatype package, INCOMPATIBILITY.
  1356 
  1357   foo.ind        ~> foo.induct
  1358   foo.finite_ind ~> foo.finite_induct
  1359   foo.coind      ~> foo.coinduct
  1360   foo.casedist   ~> foo.exhaust
  1361   foo.exhaust    ~> foo.nchotomy
  1362 
  1363 * For consistency with other definition packages, the fixrec package
  1364 now generates qualified theorem names, INCOMPATIBILITY.
  1365 
  1366   foo_simps  ~> foo.simps
  1367   foo_unfold ~> foo.unfold
  1368   foo_induct ~> foo.induct
  1369 
  1370 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1371 method and internal fixrec proofs now use the default simpset instead.
  1372 INCOMPATIBILITY.
  1373 
  1374 * The "contlub" predicate has been removed.  Proof scripts should use
  1375 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1376 
  1377 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1378 
  1379 * The constants cpair, cfst, and csnd have been removed in favor of
  1380 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1381 
  1382 
  1383 *** ML ***
  1384 
  1385 * Antiquotations for basic formal entities:
  1386 
  1387     @{class NAME}         -- type class
  1388     @{class_syntax NAME}  -- syntax representation of the above
  1389 
  1390     @{type_name NAME}     -- logical type
  1391     @{type_abbrev NAME}   -- type abbreviation
  1392     @{nonterminal NAME}   -- type of concrete syntactic category
  1393     @{type_syntax NAME}   -- syntax representation of any of the above
  1394 
  1395     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1396     @{const_abbrev NAME}  -- abbreviated constant
  1397     @{const_syntax NAME}  -- syntax representation of any of the above
  1398 
  1399 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1400 syntax constant (cf. 'syntax' command).
  1401 
  1402 * Antiquotation @{make_string} inlines a function to print arbitrary
  1403 values similar to the ML toplevel.  The result is compiler dependent
  1404 and may fall back on "?" in certain situations.
  1405 
  1406 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1407 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1408 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1409 not work with the asynchronous Isar document model.
  1410 
  1411 * Configuration options now admit dynamic default values, depending on
  1412 the context or even global references.
  1413 
  1414 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1415 uses an efficient external library if available (for Poly/ML).
  1416 
  1417 * Renamed some important ML structures, while keeping the old names
  1418 for some time as aliases within the structure Legacy:
  1419 
  1420   OuterKeyword  ~>  Keyword
  1421   OuterLex      ~>  Token
  1422   OuterParse    ~>  Parse
  1423   OuterSyntax   ~>  Outer_Syntax
  1424   PrintMode     ~>  Print_Mode
  1425   SpecParse     ~>  Parse_Spec
  1426   ThyInfo       ~>  Thy_Info
  1427   ThyLoad       ~>  Thy_Load
  1428   ThyOutput     ~>  Thy_Output
  1429   TypeInfer     ~>  Type_Infer
  1430 
  1431 Note that "open Legacy" simplifies porting of sources, but forgetting
  1432 to remove it again will complicate porting again in the future.
  1433 
  1434 * Most operations that refer to a global context are named
  1435 accordingly, e.g. Simplifier.global_context or
  1436 ProofContext.init_global.  There are some situations where a global
  1437 context actually works, but under normal circumstances one needs to
  1438 pass the proper local context through the code!
  1439 
  1440 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1441 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1442 Pretty.pp argument to merge, which is absent in the standard
  1443 Theory_Data version.
  1444 
  1445 * Sorts.certify_sort and derived "cert" operations for types and terms
  1446 no longer minimize sorts.  Thus certification at the boundary of the
  1447 inference kernel becomes invariant under addition of class relations,
  1448 which is an important monotonicity principle.  Sorts are now minimized
  1449 in the syntax layer only, at the boundary between the end-user and the
  1450 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1451 explicitly in rare situations.
  1452 
  1453 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1454 emphasize that this is in no way a standard operation.
  1455 INCOMPATIBILITY.
  1456 
  1457 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1458 usual for resolution.  Rare INCOMPATIBILITY.
  1459 
  1460 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1461 to emphasize that these only work in a global situation (which is
  1462 quite rare).
  1463 
  1464 * Curried take and drop in library.ML; negative length is interpreted
  1465 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1466 
  1467 * Proof terms: type substitutions on proof constants now use canonical
  1468 order of type variables.  INCOMPATIBILITY for tools working with proof
  1469 terms.
  1470 
  1471 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1472 may no longer carry premises.  User-level specifications are
  1473 transformed accordingly by Thm.add_axiom/add_def.
  1474 
  1475 
  1476 *** System ***
  1477 
  1478 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1479 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1480 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1481 
  1482 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1483 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1484 respectively.
  1485 
  1486 * Old lib/scripts/polyml-platform is superseded by the
  1487 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1488 variant, even on a 64 bit machine.  The following example setting
  1489 prefers 64 bit if available:
  1490 
  1491   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1492 
  1493 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1494 Isabelle/Scala layer for advanced prover interaction and integration.
  1495 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1496 component.
  1497 
  1498 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1499 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1500 similar to the default assignment of the document preparation system
  1501 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1502 provides some operations for direct access to the font without asking
  1503 the user for manual installation.
  1504 
  1505 
  1506 
  1507 New in Isabelle2009-1 (December 2009)
  1508 -------------------------------------
  1509 
  1510 *** General ***
  1511 
  1512 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1513 one backslash should be used, even in ML sources.
  1514 
  1515 
  1516 *** Pure ***
  1517 
  1518 * Locale interpretation propagates mixins along the locale hierarchy.
  1519 The currently only available mixins are the equations used to map
  1520 local definitions to terms of the target domain of an interpretation.
  1521 
  1522 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1523 loc" to print all interpretations of locale "loc" in the theory.
  1524 Interpretations in proofs are not shown.
  1525 
  1526 * Thoroughly revised locales tutorial.  New section on conditional
  1527 interpretation.
  1528 
  1529 * On instantiation of classes, remaining undefined class parameters
  1530 are formally declared.  INCOMPATIBILITY.
  1531 
  1532 
  1533 *** Document preparation ***
  1534 
  1535 * New generalized style concept for printing terms: @{foo (style) ...}
  1536 instead of @{foo_style style ...}  (old form is still retained for
  1537 backward compatibility).  Styles can be also applied for
  1538 antiquotations prop, term_type and typeof.
  1539 
  1540 
  1541 *** HOL ***
  1542 
  1543 * New proof method "smt" for a combination of first-order logic with
  1544 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1545 fixed-size bitvectors; there is also basic support for higher-order
  1546 features (esp. lambda abstractions).  It is an incomplete decision
  1547 procedure based on external SMT solvers using the oracle mechanism;
  1548 for the SMT solver Z3, this method is proof-producing.  Certificates
  1549 are provided to avoid calling the external solvers solely for
  1550 re-checking proofs.  Due to a remote SMT service there is no need for
  1551 installing SMT solvers locally.  See src/HOL/SMT.
  1552 
  1553 * New commands to load and prove verification conditions generated by
  1554 the Boogie program verifier or derived systems (e.g. the Verifying C
  1555 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1556 
  1557 * New counterexample generator tool 'nitpick' based on the Kodkod
  1558 relational model finder.  See src/HOL/Tools/Nitpick and
  1559 src/HOL/Nitpick_Examples.
  1560 
  1561 * New commands 'code_pred' and 'values' to invoke the predicate
  1562 compiler and to enumerate values of inductive predicates.
  1563 
  1564 * A tabled implementation of the reflexive transitive closure.
  1565 
  1566 * New implementation of quickcheck uses generic code generator;
  1567 default generators are provided for all suitable HOL types, records
  1568 and datatypes.  Old quickcheck can be re-activated importing theory
  1569 Library/SML_Quickcheck.
  1570 
  1571 * New testing tool Mirabelle for automated proof tools.  Applies
  1572 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1573 every proof step in a theory.  To be used in batch mode via the
  1574 "mirabelle" utility.
  1575 
  1576 * New proof method "sos" (sum of squares) for nonlinear real
  1577 arithmetic (originally due to John Harison). It requires theory
  1578 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1579 works well in practice on quantifier-free real arithmetic with +, -,
  1580 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1581 inequalities between polynomials.  It makes use of external
  1582 semidefinite programming solvers.  Method "sos" generates a
  1583 certificate that can be pasted into the proof thus avoiding the need
  1584 to call an external tool every time the proof is checked.  See
  1585 src/HOL/Library/Sum_Of_Squares.
  1586 
  1587 * New method "linarith" invokes existing linear arithmetic decision
  1588 procedure only.
  1589 
  1590 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1591 
  1592 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1593 Causes full type information to be output to the ATPs.  This slows
  1594 ATPs down considerably but eliminates a source of unsound "proofs"
  1595 that fail later.
  1596 
  1597 * New method "metisFT": A version of metis that uses full type
  1598 information in order to avoid failures of proof reconstruction.
  1599 
  1600 * New evaluator "approximate" approximates an real valued term using
  1601 the same method as the approximation method.
  1602 
  1603 * Method "approximate" now supports arithmetic expressions as
  1604 boundaries of intervals and implements interval splitting and Taylor
  1605 series expansion.
  1606 
  1607 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1608 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1609 
  1610 * New theory SupInf of the supremum and infimum operators for sets of
  1611 reals.
  1612 
  1613 * New theory Probability, which contains a development of measure
  1614 theory, eventually leading to Lebesgue integration and probability.
  1615 
  1616 * Extended Multivariate Analysis to include derivation and Brouwer's
  1617 fixpoint theorem.
  1618 
  1619 * Reorganization of number theory, INCOMPATIBILITY:
  1620   - new number theory development for nat and int, in theories Divides
  1621     and GCD as well as in new session Number_Theory
  1622   - some constants and facts now suffixed with _nat and _int
  1623     accordingly
  1624   - former session NumberTheory now named Old_Number_Theory, including
  1625     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1626   - moved theory Pocklington from src/HOL/Library to
  1627     src/HOL/Old_Number_Theory
  1628 
  1629 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1630 lcm of finite and infinite sets. It is shown that they form a complete
  1631 lattice.
  1632 
  1633 * Class semiring_div requires superclass no_zero_divisors and proof of
  1634 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1635 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1636 generalized to class semiring_div, subsuming former theorems
  1637 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1638 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1639 INCOMPATIBILITY.
  1640 
  1641 * Refinements to lattice classes and sets:
  1642   - less default intro/elim rules in locale variant, more default
  1643     intro/elim rules in class variant: more uniformity
  1644   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1645     le_inf_iff
  1646   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1647     sup_aci)
  1648   - renamed ACI to inf_sup_aci
  1649   - new class "boolean_algebra"
  1650   - class "complete_lattice" moved to separate theory
  1651     "Complete_Lattice"; corresponding constants (and abbreviations)
  1652     renamed and with authentic syntax:
  1653     Set.Inf ~>    Complete_Lattice.Inf
  1654     Set.Sup ~>    Complete_Lattice.Sup
  1655     Set.INFI ~>   Complete_Lattice.INFI
  1656     Set.SUPR ~>   Complete_Lattice.SUPR
  1657     Set.Inter ~>  Complete_Lattice.Inter
  1658     Set.Union ~>  Complete_Lattice.Union
  1659     Set.INTER ~>  Complete_Lattice.INTER
  1660     Set.UNION ~>  Complete_Lattice.UNION
  1661   - authentic syntax for
  1662     Set.Pow
  1663     Set.image
  1664   - mere abbreviations:
  1665     Set.empty               (for bot)
  1666     Set.UNIV                (for top)
  1667     Set.inter               (for inf, formerly Set.Int)
  1668     Set.union               (for sup, formerly Set.Un)
  1669     Complete_Lattice.Inter  (for Inf)
  1670     Complete_Lattice.Union  (for Sup)
  1671     Complete_Lattice.INTER  (for INFI)
  1672     Complete_Lattice.UNION  (for SUPR)
  1673   - object-logic definitions as far as appropriate
  1674 
  1675 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1676 Un_subset_iff are explicitly deleted as default simp rules; then also
  1677 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1678 deleted to achieve the desired effect.
  1679 
  1680 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1681 rules by default any longer; the same applies to min_max.inf_absorb1
  1682 etc.  INCOMPATIBILITY.
  1683 
  1684 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1685 pred_set_conv by default.  INCOMPATIBILITY.
  1686 
  1687 * Power operations on relations and functions are now one dedicated
  1688 constant "compow" with infix syntax "^^".  Power operation on
  1689 multiplicative monoids retains syntax "^" and is now defined generic
  1690 in class power.  INCOMPATIBILITY.
  1691 
  1692 * Relation composition "R O S" now has a more standard argument order:
  1693 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1694 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1695 break, since the O_assoc rule was not rewritten like this.  Fix using
  1696 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1697 
  1698 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1699 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1700 INCOMPATIBILITY.
  1701 
  1702 * Most rules produced by inductive and datatype package have mandatory
  1703 prefixes.  INCOMPATIBILITY.
  1704 
  1705 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1706 the attribute of the same name.  Each of the theorems in the list
  1707 DERIV_intros assumes composition with an additional function and
  1708 matches a variable to the derivative, which has to be solved by the
  1709 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1710 of most elementary terms.  Former Maclauren.DERIV_tac and
  1711 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1712 INCOMPATIBILITY.
  1713 
  1714 * Code generator attributes follow the usual underscore convention:
  1715     code_unfold     replaces    code unfold
  1716     code_post       replaces    code post
  1717     etc.
  1718   INCOMPATIBILITY.
  1719 
  1720 * Renamed methods:
  1721     sizechange -> size_change
  1722     induct_scheme -> induction_schema
  1723   INCOMPATIBILITY.
  1724 
  1725 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1726 INCOMPATIBILITY, use "undefined" directly.
  1727 
  1728 * Renamed theorems:
  1729     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1730     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1731     Suc_plus1 -> Suc_eq_plus1
  1732     *anti_sym -> *antisym*
  1733     vector_less_eq_def -> vector_le_def
  1734   INCOMPATIBILITY.
  1735 
  1736 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1737 INCOMPATIBILITY.
  1738 
  1739 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1740 INCOMPATIBILITY.
  1741 
  1742 
  1743 *** HOLCF ***
  1744 
  1745 * Theory Representable defines a class "rep" of domains that are
  1746 representable (via an ep-pair) in the universal domain type "udom".
  1747 Instances are provided for all type constructors defined in HOLCF.
  1748 
  1749 * The 'new_domain' command is a purely definitional version of the
  1750 domain package, for representable domains.  Syntax is identical to the
  1751 old domain package.  The 'new_domain' package also supports indirect
  1752 recursion using previously-defined type constructors.  See
  1753 src/HOLCF/ex/New_Domain.thy for examples.
  1754 
  1755 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1756 on the left-hand side of an equation, and then performs
  1757 simplification.  Rewriting is done using rules declared with the
  1758 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1759 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1760 
  1761 * The pattern-match compiler in 'fixrec' can now handle constructors
  1762 with HOL function types.  Pattern-match combinators for the Pair
  1763 constructor are pre-configured.
  1764 
  1765 * The 'fixrec' package now produces better fixed-point induction rules
  1766 for mutually-recursive definitions:  Induction rules have conclusions
  1767 of the form "P foo bar" instead of "P <foo, bar>".
  1768 
  1769 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1770 been renamed to "below".  The name "below" now replaces "less" in many
  1771 theorem names.  (Legacy theorem names using "less" are still supported
  1772 as well.)
  1773 
  1774 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1775 patterns can be used to generate strictness rules, or to make
  1776 functions more strict (much like the bang-patterns supported by the
  1777 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1778 examples.
  1779 
  1780 
  1781 *** ML ***
  1782 
  1783 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1784 errors and run-time exceptions, including detailed source positions.
  1785 
  1786 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1787 identified entries, with some additional information such as source
  1788 position, logical grouping etc.
  1789 
  1790 * Theory and context data is now introduced by the simplified and
  1791 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1792 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1793 copy operation) is still available for some time.
  1794 
  1795 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1796 provides a high-level programming interface to synchronized state
  1797 variables with atomic update.  This works via pure function
  1798 application within a critical section -- its runtime should be as
  1799 short as possible; beware of deadlocks if critical code is nested,
  1800 either directly or indirectly via other synchronized variables!
  1801 
  1802 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1803 wraps raw ML references, explicitly indicating their non-thread-safe
  1804 behaviour.  The Isar toplevel keeps this structure open, to
  1805 accommodate Proof General as well as quick and dirty interactive
  1806 experiments with references.
  1807 
  1808 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1809 parallel tactical reasoning.
  1810 
  1811 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1812 are similar to SUBPROOF, but are slightly more flexible: only the
  1813 specified parts of the subgoal are imported into the context, and the
  1814 body tactic may introduce new subgoals and schematic variables.
  1815 
  1816 * Old tactical METAHYPS, which does not observe the proof context, has
  1817 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1818 or Subgoal.FOCUS etc.
  1819 
  1820 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1821 functors have their own ML name space there is no point to mark them
  1822 separately.)  Minor INCOMPATIBILITY.
  1823 
  1824 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1825 
  1826 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1827 INCOMPATIBILITY.
  1828 
  1829 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1830 mode, which avoids critical setmp.
  1831 
  1832 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1833 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1834 Attrib/Method.setup introduced in Isabelle2009.
  1835 
  1836 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1837 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1838 last resort.  INCOMPATIBILITY.
  1839 
  1840 * Display.pretty_thm now requires a proper context (cf. former
  1841 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1842 or even Display.pretty_thm_without_context as last resort.
  1843 INCOMPATIBILITY.
  1844 
  1845 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1846 Syntax.pretty_typ/term directly, preferably with proper context
  1847 instead of global theory.
  1848 
  1849 
  1850 *** System ***
  1851 
  1852 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1853 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1854 usedir option -q.
  1855 
  1856 * Support for additional "Isabelle components" via etc/components, see
  1857 also the system manual.
  1858 
  1859 * The isabelle makeall tool now operates on all components with
  1860 IsaMakefile, not just hardwired "logics".
  1861 
  1862 * Removed "compress" option from isabelle-process and isabelle usedir;
  1863 this is always enabled.
  1864 
  1865 * Discontinued support for Poly/ML 4.x versions.
  1866 
  1867 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1868 on a given logic image.  This requires the lighttpd webserver and is
  1869 currently supported on Linux only.
  1870 
  1871 
  1872 
  1873 New in Isabelle2009 (April 2009)
  1874 --------------------------------
  1875 
  1876 *** General ***
  1877 
  1878 * Simplified main Isabelle executables, with less surprises on
  1879 case-insensitive file-systems (such as Mac OS).
  1880 
  1881   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1882     "isatool."
  1883 
  1884   - The former "isabelle" alias for "isabelle-process" has been
  1885     removed (should rarely occur to regular users).
  1886 
  1887   - The former "isabelle-interface" and its alias "Isabelle" have been
  1888     removed (interfaces are now regular Isabelle tools).
  1889 
  1890 Within scripts and make files, the Isabelle environment variables
  1891 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1892 respectively.  (The latter are still available as legacy feature.)
  1893 
  1894 The old isabelle-interface wrapper could react in confusing ways if
  1895 the interface was uninstalled or changed otherwise.  Individual
  1896 interface tool configuration is now more explicit, see also the
  1897 Isabelle system manual.  In particular, Proof General is now available
  1898 via "isabelle emacs".
  1899 
  1900 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1901 purge installed copies of Isabelle executables and re-run "isabelle
  1902 install -p ...", or use symlinks.
  1903 
  1904 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1905 old ~/isabelle, which was slightly non-standard and apt to cause
  1906 surprises on case-insensitive file-systems (such as Mac OS).
  1907 
  1908 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1909 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1910 care is required when using older releases of Isabelle.  Note that
  1911 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1912 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1913 
  1914 * Proofs of fully specified statements are run in parallel on
  1915 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1916 a regular 4-core machine, if the initial heap space is made reasonably
  1917 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1918 
  1919 * The main reference manuals ("isar-ref", "implementation", and
  1920 "system") have been updated and extended.  Formally checked references
  1921 as hyperlinks are now available uniformly.
  1922 
  1923 
  1924 *** Pure ***
  1925 
  1926 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1927 respects.  The most important changes are listed below.  See the
  1928 Tutorial on Locales ("locales" manual) for details.
  1929 
  1930 - In locale expressions, instantiation replaces renaming.  Parameters
  1931 must be declared in a for clause.  To aid compatibility with previous
  1932 parameter inheritance, in locale declarations, parameters that are not
  1933 'touched' (instantiation position "_" or omitted) are implicitly added
  1934 with their syntax at the beginning of the for clause.
  1935 
  1936 - Syntax from abbreviations and definitions in locales is available in
  1937 locale expressions and context elements.  The latter is particularly
  1938 useful in locale declarations.
  1939 
  1940 - More flexible mechanisms to qualify names generated by locale
  1941 expressions.  Qualifiers (prefixes) may be specified in locale
  1942 expressions, and can be marked as mandatory (syntax: "name!:") or
  1943 optional (syntax "name?:").  The default depends for plain "name:"
  1944 depends on the situation where a locale expression is used: in
  1945 commands 'locale' and 'sublocale' prefixes are optional, in
  1946 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1947 implicit qualifiers derived from the parameter names of a locale are
  1948 no longer generated.
  1949 
  1950 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1951 instantiation clause in "interpretation" and "interpret" (square
  1952 brackets) is no longer available.  Use locale expressions.
  1953 
  1954 - When converting proof scripts, mandatory qualifiers in
  1955 'interpretation' and 'interpret' should be retained by default, even
  1956 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1957 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1958 in locale expressions range over a single locale instance only.
  1959 
  1960 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1961 In existing theorem specifications replace the includes element by the
  1962 respective context elements of the included locale, omitting those
  1963 that are already present in the theorem specification.  Multiple
  1964 assume elements of a locale should be replaced by a single one
  1965 involving the locale predicate.  In the proof body, declarations (most
  1966 notably theorems) may be regained by interpreting the respective
  1967 locales in the proof context as required (command "interpret").
  1968 
  1969 If using "includes" in replacement of a target solely because the
  1970 parameter types in the theorem are not as general as in the target,
  1971 consider declaring a new locale with additional type constraints on
  1972 the parameters (context element "constrains").
  1973 
  1974 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1975 
  1976 - Locale interpretation commands no longer attempt to simplify goal.
  1977 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1978 methods intro_locales and unfold_locales to clarify.
  1979 
  1980 - Locale interpretation commands no longer accept interpretation
  1981 attributes.  INCOMPATIBILITY.
  1982 
  1983 * Class declaration: so-called "base sort" must not be given in import
  1984 list any longer, but is inferred from the specification.  Particularly
  1985 in HOL, write
  1986 
  1987     class foo = ...
  1988 
  1989 instead of
  1990 
  1991     class foo = type + ...
  1992 
  1993 * Class target: global versions of theorems stemming do not carry a
  1994 parameter prefix any longer.  INCOMPATIBILITY.
  1995 
  1996 * Class 'instance' command no longer accepts attached definitions.
  1997 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1998 
  1999 * Recovered hiding of consts, which was accidentally broken in
  2000 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2001 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2002 
  2003 * Slightly more coherent Pure syntax, with updated documentation in
  2004 isar-ref manual.  Removed locales meta_term_syntax and
  2005 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2006 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2007 directly in regular applications.
  2008 
  2009 * There is a new syntactic category "float_const" for signed decimal
  2010 fractions (e.g. 123.45 or -123.45).
  2011 
  2012 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2013 interface with 'setup' command instead.
  2014 
  2015 * Command 'local_setup' is similar to 'setup', but operates on a local
  2016 theory context.
  2017 
  2018 * The 'axiomatization' command now only works within a global theory
  2019 context.  INCOMPATIBILITY.
  2020 
  2021 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2022 hypotheses.  Sorts required in the course of reasoning need to be
  2023 covered by the constraints in the initial statement, completed by the
  2024 type instance information of the background theory.  Non-trivial sort
  2025 hypotheses, which rarely occur in practice, may be specified via
  2026 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2027 
  2028   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2029 
  2030 The result contains an implicit sort hypotheses as before --
  2031 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2032 normalization.
  2033 
  2034 * Generalized Isar history, with support for linear undo, direct state
  2035 addressing etc.
  2036 
  2037 * Changed defaults for unify configuration options:
  2038 
  2039   unify_trace_bound = 50 (formerly 25)
  2040   unify_search_bound = 60 (formerly 30)
  2041 
  2042 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2043 
  2044   a) On theory merge, the last set of code equations for a particular
  2045      constant is taken (in accordance with the policy applied by other
  2046      parts of the code generator framework).
  2047 
  2048   b) Code equations stemming from explicit declarations (e.g. code
  2049      attribute) gain priority over default code equations stemming
  2050      from definition, primrec, fun etc.
  2051 
  2052 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2053 
  2054 * Unified theorem tables for both code generators.  Thus [code
  2055 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2056 
  2057 * Command 'find_consts' searches for constants based on type and name
  2058 patterns, e.g.
  2059 
  2060     find_consts "_ => bool"
  2061 
  2062 By default, matching is against subtypes, but it may be restricted to
  2063 the whole type.  Searching by name is possible.  Multiple queries are
  2064 conjunctive and queries may be negated by prefixing them with a
  2065 hyphen:
  2066 
  2067     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2068 
  2069 * New 'find_theorems' criterion "solves" matches theorems that
  2070 directly solve the current goal (modulo higher-order unification).
  2071 
  2072 * Auto solve feature for main theorem statements: whenever a new goal
  2073 is stated, "find_theorems solves" is called; any theorems that could
  2074 solve the lemma directly are listed as part of the goal state.
  2075 Cf. associated options in Proof General Isabelle settings menu,
  2076 enabled by default, with reasonable timeout for pathological cases of
  2077 higher-order unification.
  2078 
  2079 
  2080 *** Document preparation ***
  2081 
  2082 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2083 demanding keyword 'by' and supporting the full method expression
  2084 syntax just like the Isar command 'by'.
  2085 
  2086 
  2087 *** HOL ***
  2088 
  2089 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2090 points Main and Complex_Main remain as before.
  2091 
  2092 * Logic image HOL-Plain provides a minimal HOL with the most important
  2093 tools available (inductive, datatype, primrec, ...).  This facilitates
  2094 experimentation and tool development.  Note that user applications
  2095 (and library theories) should never refer to anything below theory
  2096 Main, as before.
  2097 
  2098 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2099 experimentation due to shorter build times.
  2100 
  2101 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2102 were previously part of former HOL-Complex.  Entry point Hyperreal
  2103 remains valid, but theories formerly using Complex_Main should now use
  2104 new entry point Hypercomplex.
  2105 
  2106 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2107 Posix processes.  Avoids potentially expensive forking of the ML
  2108 process.  New thread-based implementation also works on non-Unix
  2109 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2110 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2111 commands are covered in the isar-ref manual.
  2112 
  2113 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2114 sledgehammer without local ATP installation (Vampire etc.). Other
  2115 provers may be included via suitable ML wrappers, see also
  2116 src/HOL/ATP_Linkup.thy.
  2117 
  2118 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2119 menu.
  2120 
  2121 * The metis method no longer fails because the theorem is too trivial
  2122 (contains the empty clause).
  2123 
  2124 * The metis method now fails in the usual manner, rather than raising
  2125 an exception, if it determines that it cannot prove the theorem.
  2126 
  2127 * Method "coherent" implements a prover for coherent logic (see also
  2128 src/Tools/coherent.ML).
  2129 
  2130 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2131 "undefined" is the right choice to replace "arbitrary", though
  2132 logically there is no difference.  INCOMPATIBILITY.
  2133 
  2134 * Command "value" now integrates different evaluation mechanisms.  The
  2135 result of the first successful evaluation mechanism is printed.  In
  2136 square brackets a particular named evaluation mechanisms may be
  2137 specified (currently, [SML], [code] or [nbe]).  See further
  2138 src/HOL/ex/Eval_Examples.thy.
  2139 
  2140 * Normalization by evaluation now allows non-leftlinear equations.
  2141 Declare with attribute [code nbe].
  2142 
  2143 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2144 as the structured Isar versions "cases" and "induct", cf. the
  2145 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2146 are now presented as a list of individual projections
  2147 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2148 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2149 rare situations a different rule is selected --- notably nested tuple
  2150 elimination instead of former prod.exhaust: use explicit (case_tac t
  2151 rule: prod.exhaust) here.
  2152 
  2153 * Attributes "cases", "induct", "coinduct" support "del" option.
  2154 
  2155 * Removed fact "case_split_thm", which duplicates "case_split".
  2156 
  2157 * The option datatype has been moved to a new theory Option.  Renamed
  2158 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2159 
  2160 * New predicate "strict_mono" classifies strict functions on partial
  2161 orders.  With strict functions on linear orders, reasoning about
  2162 (in)equalities is facilitated by theorems "strict_mono_eq",
  2163 "strict_mono_less_eq" and "strict_mono_less".
  2164 
  2165 * Some set operations are now proper qualified constants with
  2166 authentic syntax.  INCOMPATIBILITY:
  2167 
  2168     op Int ~>   Set.Int
  2169     op Un ~>    Set.Un
  2170     INTER ~>    Set.INTER
  2171     UNION ~>    Set.UNION
  2172     Inter ~>    Set.Inter
  2173     Union ~>    Set.Union
  2174     {} ~>       Set.empty
  2175     UNIV ~>     Set.UNIV
  2176 
  2177 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2178 theory Set.
  2179 
  2180 * Auxiliary class "itself" has disappeared -- classes without any
  2181 parameter are treated as expected by the 'class' command.
  2182 
  2183 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2184 
  2185 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2186 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2187 
  2188 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2189 method "approximation".  It proves formulas on real values by using
  2190 interval arithmetic.  In the formulas are also the transcendental
  2191 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2192 allowed. For examples see
  2193 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2194 
  2195 * Theory "Reflection" now resides in HOL/Library.
  2196 
  2197 * Entry point to Word library now simply named "Word".
  2198 INCOMPATIBILITY.
  2199 
  2200 * Made source layout more coherent with logical distribution
  2201 structure:
  2202 
  2203     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2204     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2205     src/HOL/Library/GCD.thy ~> src/HOL/
  2206     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2207     src/HOL/Library/Parity.thy ~> src/HOL/
  2208     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2209     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2210     src/HOL/Real/Lubs.thy ~> src/HOL/
  2211     src/HOL/Real/PReal.thy ~> src/HOL/
  2212     src/HOL/Real/Rational.thy ~> src/HOL/
  2213     src/HOL/Real/RComplete.thy ~> src/HOL/
  2214     src/HOL/Real/RealDef.thy ~> src/HOL/
  2215     src/HOL/Real/RealPow.thy ~> src/HOL/
  2216     src/HOL/Real/Real.thy ~> src/HOL/
  2217     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2218     src/HOL/Complex/Complex.thy ~> src/HOL/
  2219     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2220     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2221     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2222     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2223     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2224     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2225     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2226     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2227     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2228     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2229     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2230     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2231     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2232     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2233     src/HOL/Real/Float ~> src/HOL/Library/
  2234     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2235     src/HOL/Real/RealVector.thy ~> src/HOL/
  2236 
  2237     src/HOL/arith_data.ML ~> src/HOL/Tools
  2238     src/HOL/hologic.ML ~> src/HOL/Tools
  2239     src/HOL/simpdata.ML ~> src/HOL/Tools
  2240     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2241     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2242     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2243     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2244     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2245     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2246     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2247 
  2248     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2249     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2250     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2251     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2252     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2253     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2254 
  2255 * If methods "eval" and "evaluation" encounter a structured proof
  2256 state with !!/==>, only the conclusion is evaluated to True (if
  2257 possible), avoiding strange error messages.
  2258 
  2259 * Method "sizechange" automates termination proofs using (a
  2260 modification of) the size-change principle.  Requires SAT solver.  See
  2261 src/HOL/ex/Termination.thy for examples.
  2262 
  2263 * Simplifier: simproc for let expressions now unfolds if bound
  2264 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2265 
  2266 * Method "arith": Linear arithmetic now ignores all inequalities when
  2267 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2268 
  2269 * New attribute "arith" for facts that should always be used
  2270 automatically by arithmetic. It is intended to be used locally in
  2271 proofs, e.g.
  2272 
  2273   assumes [arith]: "x > 0"
  2274 
  2275 Global usage is discouraged because of possible performance impact.
  2276 
  2277 * New classes "top" and "bot" with corresponding operations "top" and
  2278 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2279 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2280 
  2281 * Changed definition lemma "less_fun_def" in order to provide an
  2282 instance for preorders on functions; use lemma "less_le" instead.
  2283 INCOMPATIBILITY.
  2284 
  2285 * Theory Orderings: class "wellorder" moved here, with explicit
  2286 induction rule "less_induct" as assumption.  For instantiation of
  2287 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2288 INCOMPATIBILITY.
  2289 
  2290 * Theory Orderings: added class "preorder" as superclass of "order".
  2291 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2292 etc. slightly changed.  Some theorems named order_class.* now named
  2293 preorder_class.*.
  2294 
  2295 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2296 "diag" to "Id_on".
  2297 
  2298 * Theory Finite_Set: added a new fold combinator of type
  2299 
  2300   ('a => 'b => 'b) => 'b => 'a set => 'b
  2301 
  2302 Occasionally this is more convenient than the old fold combinator
  2303 which is now defined in terms of the new one and renamed to
  2304 fold_image.
  2305 
  2306 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2307 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2308 extended with further lemmas!).  At the moment both still exist but
  2309 the former will disappear at some point.
  2310 
  2311 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2312 class recpower.  Type-specific simp rules for various recpower types
  2313 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2314 
  2315 rat_power_0    -> power_0
  2316 rat_power_Suc  -> power_Suc
  2317 realpow_0      -> power_0
  2318 realpow_Suc    -> power_Suc
  2319 complexpow_0   -> power_0
  2320 complexpow_Suc -> power_Suc
  2321 power_poly_0   -> power_0
  2322 power_poly_Suc -> power_Suc
  2323 
  2324 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2325 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2326 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2327 of lemmas from Divides has been generalized from nat to class
  2328 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2329 renames resulting from duplicate elimination:
  2330 
  2331     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2332     zero_dvd_iff ~>         dvd_0_left_iff
  2333     dvd_0 ~>                dvd_0_right
  2334     DIVISION_BY_ZERO_DIV ~> div_by_0
  2335     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2336     mult_div ~>             div_mult_self2_is_id
  2337     mult_mod ~>             mod_mult_self2_is_0
  2338 
  2339 * Theory IntDiv: removed many lemmas that are instances of class-based
  2340 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2341 rename old lemmas as follows:
  2342 
  2343 dvd_diff               -> nat_dvd_diff
  2344 dvd_zminus_iff         -> dvd_minus_iff
  2345 mod_add1_eq            -> mod_add_eq
  2346 mod_mult1_eq           -> mod_mult_right_eq
  2347 mod_mult1_eq'          -> mod_mult_left_eq
  2348 mod_mult_distrib_mod   -> mod_mult_eq
  2349 nat_mod_add_left_eq    -> mod_add_left_eq
  2350 nat_mod_add_right_eq   -> mod_add_right_eq
  2351 nat_mod_div_trivial    -> mod_div_trivial
  2352 nat_mod_mod_trivial    -> mod_mod_trivial
  2353 zdiv_zadd_self1        -> div_add_self1
  2354 zdiv_zadd_self2        -> div_add_self2
  2355 zdiv_zmult_self1       -> div_mult_self2_is_id
  2356 zdiv_zmult_self2       -> div_mult_self1_is_id
  2357 zdvd_triv_left         -> dvd_triv_left
  2358 zdvd_triv_right        -> dvd_triv_right
  2359 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2360 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2361 zmod_zadd_left_eq      -> mod_add_left_eq
  2362 zmod_zadd_right_eq     -> mod_add_right_eq
  2363 zmod_zadd_self1        -> mod_add_self1
  2364 zmod_zadd_self2        -> mod_add_self2
  2365 zmod_zadd1_eq          -> mod_add_eq
  2366 zmod_zdiff1_eq         -> mod_diff_eq
  2367 zmod_zdvd_zmod         -> mod_mod_cancel
  2368 zmod_zmod_cancel       -> mod_mod_cancel
  2369 zmod_zmult_self1       -> mod_mult_self2_is_0
  2370 zmod_zmult_self2       -> mod_mult_self1_is_0
  2371 zmod_1                 -> mod_by_1
  2372 zdiv_1                 -> div_by_1
  2373 zdvd_abs1              -> abs_dvd_iff
  2374 zdvd_abs2              -> dvd_abs_iff
  2375 zdvd_refl              -> dvd_refl
  2376 zdvd_trans             -> dvd_trans
  2377 zdvd_zadd              -> dvd_add
  2378 zdvd_zdiff             -> dvd_diff
  2379 zdvd_zminus_iff        -> dvd_minus_iff
  2380 zdvd_zminus2_iff       -> minus_dvd_iff
  2381 zdvd_zmultD            -> dvd_mult_right
  2382 zdvd_zmultD2           -> dvd_mult_left
  2383 zdvd_zmult_mono        -> mult_dvd_mono
  2384 zdvd_0_right           -> dvd_0_right
  2385 zdvd_0_left            -> dvd_0_left_iff
  2386 zdvd_1_left            -> one_dvd
  2387 zminus_dvd_iff         -> minus_dvd_iff
  2388 
  2389 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2390 
  2391 * The real numbers offer decimal input syntax: 12.34 is translated
  2392 into 1234/10^2. This translation is not reversed upon output.
  2393 
  2394 * Theory Library/Polynomial defines an abstract type 'a poly of
  2395 univariate polynomials with coefficients of type 'a.  In addition to
  2396 the standard ring operations, it also supports div and mod.  Code
  2397 generation is also supported, using list-style constructors.
  2398 
  2399 * Theory Library/Inner_Product defines a class of real_inner for real
  2400 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2401 => real.  Class real_inner is a subclass of real_normed_vector from
  2402 theory RealVector.
  2403 
  2404 * Theory Library/Product_Vector provides instances for the product
  2405 type 'a * 'b of several classes from RealVector and Inner_Product.
  2406 Definitions of addition, subtraction, scalar multiplication, norms,
  2407 and inner products are included.
  2408 
  2409 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2410 addition to the field operations, numerals and case syntax are also
  2411 supported.
  2412 
  2413 * Theory Library/Diagonalize provides constructive version of Cantor's
  2414 first diagonalization argument.
  2415 
  2416 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2417 zlcm (for int); carried together from various gcd/lcm developements in
  2418 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2419 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2420 may recover tupled syntax as follows:
  2421 
  2422     hide (open) const gcd
  2423     abbreviation gcd where
  2424       "gcd == (%(a, b). GCD.gcd a b)"
  2425     notation (output)
  2426       GCD.gcd ("gcd '(_, _')")
  2427 
  2428 The same works for lcm, zgcd, zlcm.
  2429 
  2430 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2431 instantiations for algebraic structures.  Removed some duplicate
  2432 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2433 
  2434 * ML antiquotation @{code} takes a constant as argument and generates
  2435 corresponding code in background and inserts name of the corresponding
  2436 resulting ML value/function/datatype constructor binding in place.
  2437 All occurrences of @{code} with a single ML block are generated
  2438 simultaneously.  Provides a generic and safe interface for
  2439 instrumentalizing code generation.  See
  2440 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2441 In future you ought to refrain from ad-hoc compiling generated SML
  2442 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2443 cannot refer to constants for which user-defined serializations are
  2444 set.  Refer to the corresponding ML counterpart directly in that
  2445 cases.
  2446 
  2447 * Command 'rep_datatype': instead of theorem names the command now
  2448 takes a list of terms denoting the constructors of the type to be
  2449 represented as datatype.  The characteristic theorems have to be
  2450 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2451 have disappeared in favour of existing ones:
  2452 
  2453     unit_induct                 ~> unit.induct
  2454     prod_induct                 ~> prod.induct
  2455     sum_induct                  ~> sum.induct
  2456     Suc_Suc_eq                  ~> nat.inject
  2457     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2458 
  2459 
  2460 *** HOL-Algebra ***
  2461 
  2462 * New locales for orders and lattices where the equivalence relation
  2463 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2464 locales use a record structure with field eq for the equivalence.
  2465 
  2466 * New theory of factorial domains.
  2467 
  2468 * Units_l_inv and Units_r_inv are now simp rules by default.
  2469 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2470 and/or r_inv will now also require deletion of these lemmas.
  2471 
  2472 * Renamed the following theorems, INCOMPATIBILITY:
  2473 
  2474 UpperD ~> Upper_memD
  2475 LowerD ~> Lower_memD
  2476 least_carrier ~> least_closed
  2477 greatest_carrier ~> greatest_closed
  2478 greatest_Lower_above ~> greatest_Lower_below
  2479 one_zero ~> carrier_one_zero
  2480 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2481 
  2482 
  2483 *** HOL-Nominal ***
  2484 
  2485 * Nominal datatypes can now contain type-variables.
  2486 
  2487 * Commands 'nominal_inductive' and 'equivariance' work with local
  2488 theory targets.
  2489 
  2490 * Nominal primrec can now works with local theory targets and its
  2491 specification syntax now conforms to the general format as seen in
  2492 'inductive' etc.
  2493 
  2494 * Method "perm_simp" honours the standard simplifier attributes
  2495 (no_asm), (no_asm_use) etc.
  2496 
  2497 * The new predicate #* is defined like freshness, except that on the
  2498 left hand side can be a set or list of atoms.
  2499 
  2500 * Experimental command 'nominal_inductive2' derives strong induction
  2501 principles for inductive definitions.  In contrast to
  2502 'nominal_inductive', which can only deal with a fixed number of
  2503 binders, it can deal with arbitrary expressions standing for sets of
  2504 atoms to be avoided.  The only inductive definition we have at the
  2505 moment that needs this generalisation is the typing rule for Lets in
  2506 the algorithm W:
  2507 
  2508  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2509  -----------------------------------------------------------------
  2510          Gamma |- Let x be t1 in t2 : T2
  2511 
  2512 In this rule one wants to avoid all the binders that are introduced by
  2513 "close Gamma T1".  We are looking for other examples where this
  2514 feature might be useful.  Please let us know.
  2515 
  2516 
  2517 *** HOLCF ***
  2518 
  2519 * Reimplemented the simplification procedure for proving continuity
  2520 subgoals.  The new simproc is extensible; users can declare additional
  2521 continuity introduction rules with the attribute [cont2cont].
  2522 
  2523 * The continuity simproc now uses a different introduction rule for
  2524 solving continuity subgoals on terms with lambda abstractions.  In
  2525 some rare cases the new simproc may fail to solve subgoals that the
  2526 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2527 Potential INCOMPATIBILITY.
  2528 
  2529 * Command 'fixrec': specification syntax now conforms to the general
  2530 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2531 examples.  INCOMPATIBILITY.
  2532 
  2533 
  2534 *** ZF ***
  2535 
  2536 * Proof of Zorn's Lemma for partial orders.
  2537 
  2538 
  2539 *** ML ***
  2540 
  2541 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2542 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2543 depends on multithreading, so timouts will not work before Poly/ML
  2544 5.2.1!
  2545 
  2546 * High-level support for concurrent ML programming, see
  2547 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2548 particularly convenient to organize independent functional
  2549 computations.  The concept of "synchronized variables" provides a
  2550 higher-order interface for components with shared state, avoiding the
  2551 delicate details of mutexes and condition variables.  (Requires
  2552 Poly/ML 5.2.1 or later.)
  2553 
  2554 * ML bindings produced via Isar commands are stored within the Isar
  2555 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2556 become thread-safe and work with undo as expected (concerning
  2557 top-level bindings, not side-effects on global references).
  2558 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2559 compiler at runtime; really global bindings need to be given outside a
  2560 theory.  (Requires Poly/ML 5.2 or later.)
  2561 
  2562 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2563 context.  Top-level ML bindings are stored within the proof context in
  2564 a purely sequential fashion, disregarding the nested proof structure.
  2565 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2566 proof.  (Requires Poly/ML 5.2 or later.)
  2567 
  2568 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2569 and Method.setup, as well as Isar commands 'attribute_setup' and
  2570 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2571 existing code accordingly, or use plain 'setup' together with old
  2572 Method.add_method.
  2573 
  2574 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2575 to 'a -> thm, while results are always tagged with an authentic oracle
  2576 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2577 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2578 accordingly.  Note that extra performance may be gained by producing
  2579 the cterm carefully, avoiding slow Thm.cterm_of.
  2580 
  2581 * Simplified interface for defining document antiquotations via
  2582 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2583 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2584 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2585 examples.
  2586 
  2587 * More systematic treatment of long names, abstract name bindings, and
  2588 name space operations.  Basic operations on qualified names have been
  2589 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2590 Long_Name.append.  Old type bstring has been mostly replaced by
  2591 abstract type binding (see structure Binding), which supports precise
  2592 qualification by packages and local theory targets, as well as proper
  2593 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2594 bstring values into Binding.name, or better pass through abstract
  2595 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2596 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2597 
  2598 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2599 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2600 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2601 
  2602 * Disposed old type and term read functions (Sign.read_def_typ,
  2603 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2604 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2605 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2606 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2607 resort for legacy applications.
  2608 
  2609 * Disposed old declarations, tactics, tactic combinators that refer to
  2610 the simpset or claset of an implicit theory (such as Addsimps,
  2611 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2612 embedded ML text, or local_simpset_of with a proper context passed as
  2613 explicit runtime argument.
  2614 
  2615 * Rules and tactics that read instantiations (read_instantiate,
  2616 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2617 context, which is required for parsing and type-checking.  Moreover,
  2618 the variables are specified as plain indexnames, not string encodings
  2619 thereof.  INCOMPATIBILITY.
  2620 
  2621 * Generic Toplevel.add_hook interface allows to analyze the result of
  2622 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2623 for theorem dependency output of transactions resulting in a new
  2624 theory state.
  2625 
  2626 * ML antiquotations: block-structured compilation context indicated by
  2627 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2628 
  2629   @{binding name}                         - basic name binding
  2630   @{let ?pat = term}                      - term abbreviation (HO matching)
  2631   @{note name = fact}                     - fact abbreviation
  2632   @{thm fact}                             - singleton fact (with attributes)
  2633   @{thms fact}                            - general fact (with attributes)
  2634   @{lemma prop by method}                 - singleton goal
  2635   @{lemma prop by meth1 meth2}            - singleton goal
  2636   @{lemma prop1 ... propN by method}      - general goal
  2637   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2638   @{lemma (open) ...}                     - open derivation
  2639 
  2640 
  2641 *** System ***
  2642 
  2643 * The Isabelle "emacs" tool provides a specific interface to invoke
  2644 Proof General / Emacs, with more explicit failure if that is not
  2645 installed (the old isabelle-interface script silently falls back on
  2646 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2647 installation location of the Proof General distribution.
  2648 
  2649 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2650 the Isabelle process into a JVM/Scala application.  See
  2651 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2652 process wrapper has been discontinued.)
  2653 
  2654 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2655 
  2656 * Various status messages (with exact source position information) are
  2657 emitted, if proper markup print mode is enabled.  This allows
  2658 user-interface components to provide detailed feedback on internal
  2659 prover operations.
  2660 
  2661 
  2662 
  2663 New in Isabelle2008 (June 2008)
  2664 -------------------------------
  2665 
  2666 *** General ***
  2667 
  2668 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2669 and updated, with formally checked references as hyperlinks.
  2670 
  2671 * Theory loader: use_thy (and similar operations) no longer set the
  2672 implicit ML context, which was occasionally hard to predict and in
  2673 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2674 provides a proper context already.
  2675 
  2676 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2677 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2678 'use' within a theory file will do the job.
  2679 
  2680 * Name space merge now observes canonical order, i.e. the second space
  2681 is inserted into the first one, while existing entries in the first
  2682 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2683 swap theory imports.
  2684 
  2685 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2686 INCOMPATIBILITY in identifier syntax etc.
  2687 
  2688 * Outer syntax: string tokens no longer admit escaped white space,
  2689 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2690 white space without escapes.
  2691 
  2692 * Outer syntax: string tokens may contain arbitrary character codes
  2693 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2694 "foo_bar".
  2695 
  2696 
  2697 *** Pure ***
  2698 
  2699 * Context-dependent token translations.  Default setup reverts locally
  2700 fixed variables, and adds hilite markup for undeclared frees.
  2701 
  2702 * Unused theorems can be found using the new command 'unused_thms'.
  2703 There are three ways of invoking it:
  2704 
  2705 (1) unused_thms
  2706      Only finds unused theorems in the current theory.
  2707 
  2708 (2) unused_thms thy_1 ... thy_n -
  2709      Finds unused theorems in the current theory and all of its ancestors,
  2710      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2711 
  2712 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2713      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2714      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2715      their ancestors.
  2716 
  2717 In order to increase the readability of the list produced by
  2718 unused_thms, theorems that have been created by a particular instance
  2719 of a theory command such as 'inductive' or 'function' are considered
  2720 to belong to the same "group", meaning that if at least one theorem in
  2721 this group is used, the other theorems in the same group are no longer
  2722 reported as unused.  Moreover, if all theorems in the group are
  2723 unused, only one theorem in the group is displayed.
  2724 
  2725 Note that proof objects have to be switched on in order for
  2726 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2727 usually the case when using Proof General with the default settings).
  2728 
  2729 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2730 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2731 duplicate fact bindings, or even accidental fact duplications.  Note
  2732 that tools may maintain dynamically scoped facts systematically, using
  2733 PureThy.add_thms_dynamic.
  2734 
  2735 * Command 'hide' now allows to hide from "fact" name space as well.
  2736 
  2737 * Eliminated destructive theorem database, simpset, claset, and
  2738 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2739 update of theories within ML code.
  2740 
  2741 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2742 INCOMPATIBILITY, object-logics depending on former Pure require
  2743 additional setup PureThy.old_appl_syntax_setup; object-logics
  2744 depending on former CPure need to refer to Pure.
  2745 
  2746 * Commands 'use' and 'ML' are now purely functional, operating on
  2747 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2748 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2749 INCOMPATIBILITY.
  2750 
  2751 * Command 'setup': discontinued implicit version with ML reference.
  2752 
  2753 * Instantiation target allows for simultaneous specification of class
  2754 instance operations together with an instantiation proof.
  2755 Type-checking phase allows to refer to class operations uniformly.
  2756 See src/HOL/Complex/Complex.thy for an Isar example and
  2757 src/HOL/Library/Eval.thy for an ML example.
  2758 
  2759 * Indexing of literal facts: be more serious about including only
  2760 facts from the visible specification/proof context, but not the
  2761 background context (locale etc.).  Affects `prop` notation and method
  2762 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2763 situations.
  2764 
  2765 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2766 "(open)" option, which used to expose internal bound variables to the
  2767 proof text.
  2768 
  2769 * Isar statements: removed obsolete case "rule_context".
  2770 INCOMPATIBILITY, better use explicit fixes/assumes.
  2771 
  2772 * Locale proofs: default proof step now includes 'unfold_locales';
  2773 hence 'proof' without argument may be used to unfold locale
  2774 predicates.
  2775 
  2776 
  2777 *** Document preparation ***
  2778 
  2779 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2780 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2781 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2782 spot); renamed link color from "darkblue" to "linkcolor" (default
  2783 value unchanged, can be redefined via \definecolor); no longer sets
  2784 "a4paper" option (unnecessary or even intrusive).
  2785 
  2786 * Antiquotation @{lemma A method} proves proposition A by the given
  2787 method (either a method name or a method name plus (optional) method
  2788 arguments in parentheses) and prints A just like @{prop A}.
  2789 
  2790 
  2791 *** HOL ***
  2792 
  2793 * New primrec package.  Specification syntax conforms in style to
  2794 definition/function/....  No separate induction rule is provided.  The
  2795 "primrec" command distinguishes old-style and new-style specifications
  2796 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2797 When adjusting theories, beware: constants stemming from new-style
  2798 primrec specifications have authentic syntax.
  2799 
  2800 * Metis prover is now an order of magnitude faster, and also works
  2801 with multithreading.
  2802 
  2803 * Metis: the maximum number of clauses that can be produced from a
  2804 theorem is now given by the attribute max_clauses.  Theorems that
  2805 exceed this number are ignored, with a warning printed.
  2806 
  2807 * Sledgehammer no longer produces structured proofs by default. To
  2808 enable, declare [[sledgehammer_full = true]].  Attributes
  2809 reconstruction_modulus, reconstruction_sorts renamed
  2810 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2811 
  2812 * Method "induct_scheme" derives user-specified induction rules
  2813 from well-founded induction and completeness of patterns. This factors
  2814 out some operations that are done internally by the function package
  2815 and makes them available separately.  See
  2816 src/HOL/ex/Induction_Scheme.thy for examples.
  2817 
  2818 * More flexible generation of measure functions for termination
  2819 proofs: Measure functions can be declared by proving a rule of the
  2820 form "is_measure f" and giving it the [measure_function] attribute.
  2821 The "is_measure" predicate is logically meaningless (always true), and
  2822 just guides the heuristic.  To find suitable measure functions, the
  2823 termination prover sets up the goal "is_measure ?f" of the appropriate
  2824 type and generates all solutions by prolog-style backwards proof using
  2825 the declared rules.
  2826 
  2827 This setup also deals with rules like 
  2828 
  2829   "is_measure f ==> is_measure (list_size f)"
  2830 
  2831 which accommodates nested datatypes that recurse through lists.
  2832 Similar rules are predeclared for products and option types.
  2833 
  2834 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2835 
  2836   INCOMPATIBILITIES:
  2837 
  2838   - Definitions of overloaded constants on sets have to be replaced by
  2839     definitions on => and bool.
  2840 
  2841   - Some definitions of overloaded operators on sets can now be proved
  2842     using the definitions of the operators on => and bool.  Therefore,
  2843     the following theorems have been renamed:
  2844 
  2845       subset_def   -> subset_eq
  2846       psubset_def  -> psubset_eq
  2847       set_diff_def -> set_diff_eq
  2848       Compl_def    -> Compl_eq
  2849       Sup_set_def  -> Sup_set_eq
  2850       Inf_set_def  -> Inf_set_eq
  2851       sup_set_def  -> sup_set_eq
  2852       inf_set_def  -> inf_set_eq
  2853 
  2854   - Due to the incompleteness of the HO unification algorithm, some
  2855     rules such as subst may require manual instantiation, if some of
  2856     the unknowns in the rule is a set.
  2857 
  2858   - Higher order unification and forward proofs:
  2859     The proof pattern
  2860 
  2861       have "P (S::'a set)" <...>
  2862       then have "EX S. P S" ..
  2863 
  2864     no longer works (due to the incompleteness of the HO unification
  2865     algorithm) and must be replaced by the pattern
  2866 
  2867       have "EX S. P S"
  2868       proof
  2869         show "P S" <...>
  2870       qed
  2871 
  2872   - Calculational reasoning with subst (or similar rules):
  2873     The proof pattern
  2874 
  2875       have "P (S::'a set)" <...>
  2876       also have "S = T" <...>
  2877       finally have "P T" .
  2878 
  2879     no longer works (for similar reasons as the previous example) and
  2880     must be replaced by something like
  2881 
  2882       have "P (S::'a set)" <...>
  2883       moreover have "S = T" <...>
  2884       ultimately have "P T" by simp
  2885 
  2886   - Tactics or packages written in ML code:
  2887     Code performing pattern matching on types via
  2888 
  2889       Type ("set", [T]) => ...
  2890 
  2891     must be rewritten. Moreover, functions like strip_type or
  2892     binder_types no longer return the right value when applied to a
  2893     type of the form
  2894 
  2895       T1 => ... => Tn => U => bool
  2896 
  2897     rather than
  2898 
  2899       T1 => ... => Tn => U set
  2900 
  2901 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2902 Wellfounded_Relations to theory Wellfounded.
  2903 
  2904 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2905 
  2906 * Class finite no longer treats UNIV as class parameter.  Use class
  2907 enum from theory Library/Enum instead to achieve a similar effect.
  2908 INCOMPATIBILITY.
  2909 
  2910 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2911 and "Cons".  INCOMPATIBILITY.
  2912 
  2913 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2914 Potential INCOMPATIBILITY.
  2915 
  2916 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2917 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2918 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2919 
  2920 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2921 the same name in theory Orderings:
  2922 
  2923   less_trans
  2924   less_linear
  2925   le_imp_less_or_eq
  2926   le_less_trans
  2927   less_le_trans
  2928   less_not_sym
  2929   less_asym
  2930 
  2931 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2932 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2933 and different variable names.
  2934 
  2935 * Library/Option_ord.thy: Canonical order on option type.
  2936 
  2937 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2938 finite maps.
  2939 
  2940 * Library/Countable.thy: Type class for countable types.
  2941 
  2942 * Theory Int: The representation of numerals has changed.  The infix
  2943 operator BIT and the bit datatype with constructors B0 and B1 have
  2944 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2945 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2946 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2947 accordingly.
  2948 
  2949 * Theory Nat: definition of <= and < on natural numbers no longer
  2950 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2951 le_def and less_def have disappeared.  Consider lemmas not_less
  2952 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2953 
  2954 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2955 (whose purpose mainly is for various fold_set functionals) have been
  2956 abandoned in favor of the existing algebraic classes
  2957 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2958 lower_semilattice (resp. upper_semilattice) and linorder.
  2959 INCOMPATIBILITY.
  2960 
  2961 * Theory Transitive_Closure: induct and cases rules now declare proper
  2962 case_names ("base" and "step").  INCOMPATIBILITY.
  2963 
  2964 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2965 lattices.  The form set-specific version is available as
  2966 Inductive.lfp_ordinal_induct_set.
  2967 
  2968 * Renamed theorems "power.simps" to "power_int.simps".
  2969 INCOMPATIBILITY.
  2970 
  2971 * Class semiring_div provides basic abstract properties of semirings
  2972 with division and modulo operations.  Subsumes former class dvd_mod.
  2973 
  2974 * Merged theories IntDef, Numeral and IntArith into unified theory
  2975 Int.  INCOMPATIBILITY.
  2976 
  2977 * Theory Library/Code_Index: type "index" now represents natural
  2978 numbers rather than integers.  INCOMPATIBILITY.
  2979 
  2980 * New class "uminus" with operation "uminus" (split of from class
  2981 "minus" which now only has operation "minus", binary).
  2982 INCOMPATIBILITY.
  2983 
  2984 * Constants "card", "internal_split", "option_map" now with authentic
  2985 syntax.  INCOMPATIBILITY.
  2986 
  2987 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2988 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2989 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2990 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2991 Sup_set_def, le_def, less_def, option_map_def now with object
  2992 equality.  INCOMPATIBILITY.
  2993 
  2994 * Records. Removed K_record, and replaced it by pure lambda term
  2995 %x. c. The simplifier setup is now more robust against eta expansion.
  2996 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2997 
  2998 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2999 
  3000 * Library/ListVector: new theory of arithmetic vector operations.
  3001 
  3002 * Library/Order_Relation: new theory of various orderings as sets of
  3003 pairs.  Defines preorders, partial orders, linear orders and
  3004 well-orders on sets and on types.
  3005 
  3006 
  3007 *** ZF ***
  3008 
  3009 * Renamed some theories to allow to loading both ZF and HOL in the
  3010 same session:
  3011 
  3012   Datatype  -> Datatype_ZF
  3013   Inductive -> Inductive_ZF
  3014   Int       -> Int_ZF
  3015   IntDiv    -> IntDiv_ZF
  3016   Nat       -> Nat_ZF
  3017   List      -> List_ZF
  3018   Main      -> Main_ZF
  3019 
  3020 INCOMPATIBILITY: ZF theories that import individual theories below
  3021 Main might need to be adapted.  Regular theory Main is still
  3022 available, as trivial extension of Main_ZF.
  3023 
  3024 
  3025 *** ML ***
  3026 
  3027 * ML within Isar: antiquotation @{const name} or @{const
  3028 name(typargs)} produces statically-checked Const term.
  3029 
  3030 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3031 (of the same name).  Removed obsolete print command.
  3032 
  3033 * Removed obsolete "use_legacy_bindings" function.
  3034 
  3035 * The ``print mode'' is now a thread-local value derived from a global
  3036 template (the former print_mode reference), thus access becomes
  3037 non-critical.  The global print_mode reference is for session
  3038 management only; user-code should use print_mode_value,
  3039 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3040 
  3041 * Functions system/system_out provide a robust way to invoke external
  3042 shell commands, with propagation of interrupts (requires Poly/ML
  3043 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3044 
  3045 
  3046 *** System ***
  3047 
  3048 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3049 in accordance with Proof General 3.7, which prefers GNU emacs.
  3050 
  3051 * isatool tty runs Isabelle process with plain tty interaction;
  3052 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3053 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3054 
  3055 * isatool browser now works with Cygwin as well, using general
  3056 "javapath" function defined in Isabelle process environment.
  3057 
  3058 * YXML notation provides a simple and efficient alternative to
  3059 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3060 isatool yxml as described in the Isabelle system manual.
  3061 
  3062 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3063 provides general wrapper for managing an Isabelle process in a robust
  3064 fashion, with ``cooked'' output from stdin/stderr.
  3065 
  3066 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3067 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3068 
  3069 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3070 way of changing the user's settings is via
  3071 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3072 script.
  3073 
  3074 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3075 cores of the underlying machine, which is a good starting point for
  3076 optimal performance tuning.  The corresponding usedir option -M allows
  3077 "max" as an alias for "0".  WARNING: does not work on certain versions
  3078 of Mac OS (with Poly/ML 5.1).
  3079 
  3080 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3081 adverse effect of Isabelle flooding interactive front-ends (notably
  3082 ProofGeneral / XEmacs).
  3083 
  3084 
  3085 
  3086 New in Isabelle2007 (November 2007)
  3087 -----------------------------------
  3088 
  3089 *** General ***
  3090 
  3091 * More uniform information about legacy features, notably a
  3092 warning/error of "Legacy feature: ...", depending on the state of the
  3093 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3094 legacy features will disappear eventually.
  3095 
  3096 * Theory syntax: the header format ``theory A = B + C:'' has been
  3097 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3098 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3099 
  3100 * Theory syntax: the old non-Isar theory file format has been
  3101 discontinued altogether.  Note that ML proof scripts may still be used
  3102 with Isar theories; migration is usually quite simple with the ML
  3103 function use_legacy_bindings.  INCOMPATIBILITY.
  3104 
  3105 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3106 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3107 quotes.
  3108 
  3109 * Theory loader: be more serious about observing the static theory
  3110 header specifications (including optional directories), but not the
  3111 accidental file locations of previously successful loads.  The strict
  3112 update policy of former update_thy is now already performed by
  3113 use_thy, so the former has been removed; use_thys updates several
  3114 theories simultaneously, just as 'imports' within a theory header
  3115 specification, but without merging the results.  Potential
  3116 INCOMPATIBILITY: may need to refine theory headers and commands
  3117 ROOT.ML which depend on load order.
  3118 
  3119 * Theory loader: optional support for content-based file
  3120 identification, instead of the traditional scheme of full physical
  3121 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3122 (cf. the system manual).  The new scheme allows to work with
  3123 non-finished theories in persistent session images, such that source
  3124 files may be moved later on without requiring reloads.
  3125 
  3126 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3127 file (with the same base name as the theory) are considered a legacy
  3128 feature, which will disappear eventually. Even now, the theory loader
  3129 no longer maintains dependencies on such files.
  3130 
  3131 * Syntax: the scope for resolving ambiguities via type-inference is
  3132 now limited to individual terms, instead of whole simultaneous
  3133 specifications as before. This greatly reduces the complexity of the
  3134 syntax module and improves flexibility by separating parsing and
  3135 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3136 'fixes' etc.) are required in rare situations.
  3137 
  3138 * Syntax: constants introduced by new-style packages ('definition',
  3139 'abbreviation' etc.) are passed through the syntax module in
  3140 ``authentic mode''. This means that associated mixfix annotations
  3141 really stick to such constants, independently of potential name space
  3142 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3143 trees are represented slightly differently, may need to adapt syntax
  3144 translations accordingly. Use CONST marker in 'translations' and
  3145 @{const_syntax} antiquotation in 'parse_translation' etc.
  3146 
  3147 * Legacy goal package: reduced interface to the bare minimum required
  3148 to keep existing proof scripts running.  Most other user-level
  3149 functions are now part of the OldGoals structure, which is *not* open
  3150 by default (consider isatool expandshort before open OldGoals).
  3151 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3152 these tend to cause confusion about the actual goal (!) context being
  3153 used here, which is not necessarily the same as the_context().
  3154 
  3155 * Command 'find_theorems': supports "*" wild-card in "name:"
  3156 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3157 support a specific search form (see ProofGeneral/CHANGES).
  3158 
  3159 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3160 by default, which means that "prems" (and also "fixed variables") are
  3161 suppressed from proof state output.  Note that the ProofGeneral
  3162 settings mechanism allows to change and save options persistently, but
  3163 older versions of Isabelle will fail to start up if a negative prems
  3164 limit is imposed.
  3165 
  3166 * Local theory targets may be specified by non-nested blocks of
  3167 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3168 contain definitions, theorems etc., including any derived mechanism
  3169 that has been implemented on top of these primitives.  This concept
  3170 generalizes the existing ``theorem (in ...)'' towards more versatility
  3171 and scalability.
  3172 
  3173 * Proof General interface: proper undo of final 'end' command;
  3174 discontinued Isabelle/classic mode (ML proof scripts).
  3175 
  3176 
  3177 *** Document preparation ***
  3178 
  3179 * Added antiquotation @{theory name} which prints the given name,
  3180 after checking that it refers to a valid ancestor theory in the
  3181 current context.
  3182 
  3183 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3184 check the given source text as ML type/structure, printing verbatim.
  3185 
  3186 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3187 "c args == rhs" given in the current context.  (Any number of
  3188 arguments may be given on the LHS.)
  3189 
  3190 
  3191 *** Pure ***
  3192 
  3193 * The 'class' package offers a combination of axclass and locale to
  3194 achieve Haskell-like type classes in Isabelle.  Definitions and
  3195 theorems within a class context produce both relative results (with
  3196 implicit parameters according to the locale context), and polymorphic
  3197 constants with qualified polymorphism (according to the class
  3198 context).  Within the body context of a 'class' target, a separate
  3199 syntax layer ("user space type system") takes care of converting
  3200 between global polymorphic consts and internal locale representation.
  3201 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3202 "isatool doc classes" provides a tutorial.
  3203 
  3204 * Generic code generator framework allows to generate executable
  3205 code for ML and Haskell (including Isabelle classes).  A short usage
  3206 sketch:
  3207 
  3208     internal compilation:
  3209         export_code <list of constants (term syntax)> in SML
  3210     writing SML code to a file:
  3211         export_code <list of constants (term syntax)> in SML <filename>
  3212     writing OCaml code to a file:
  3213         export_code <list of constants (term syntax)> in OCaml <filename>
  3214     writing Haskell code to a bunch of files:
  3215         export_code <list of constants (term syntax)> in Haskell <filename>
  3216 
  3217     evaluating closed propositions to True/False using code generation:
  3218         method ``eval''
  3219 
  3220 Reasonable default setup of framework in HOL.
  3221 
  3222 Theorem attributs for selecting and transforming function equations theorems:
  3223 
  3224     [code fun]:        select a theorem as function equation for a specific constant
  3225     [code fun del]:    deselect a theorem as function equation for a specific constant
  3226     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3227     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3228 
  3229 User-defined serializations (target in {SML, OCaml, Haskell}):
  3230 
  3231     code_const <and-list of constants (term syntax)>
  3232       {(target) <and-list of const target syntax>}+
  3233 
  3234     code_type <and-list of type constructors>
  3235       {(target) <and-list of type target syntax>}+
  3236 
  3237     code_instance <and-list of instances>
  3238       {(target)}+
  3239         where instance ::= <type constructor> :: <class>
  3240 
  3241     code_class <and_list of classes>
  3242       {(target) <and-list of class target syntax>}+
  3243         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3244 
  3245 code_instance and code_class only are effective to target Haskell.
  3246 
  3247 For example usage see src/HOL/ex/Codegenerator.thy and
  3248 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3249 generation from Isabelle/HOL theories is available via "isatool doc
  3250 codegen".
  3251 
  3252 * Code generator: consts in 'consts_code' Isar commands are now
  3253 referred to by usual term syntax (including optional type
  3254 annotations).
  3255 
  3256 * Command 'no_translations' removes translation rules from theory
  3257 syntax.
  3258 
  3259 * Overloaded definitions are now actually checked for acyclic
  3260 dependencies.  The overloading scheme is slightly more general than
  3261 that of Haskell98, although Isabelle does not demand an exact
  3262 correspondence to type class and instance declarations.
  3263 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3264 exotic versions of overloading -- at the discretion of the user!
  3265 
  3266 Polymorphic constants are represented via type arguments, i.e. the
  3267 instantiation that matches an instance against the most general
  3268 declaration given in the signature.  For example, with the declaration
  3269 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3270 as c(nat).  Overloading is essentially simultaneous structural
  3271 recursion over such type arguments.  Incomplete specification patterns
  3272 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3273 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3274 Command 'print_theory' outputs the normalized system of recursive
  3275 equations, see section "definitions".
  3276 
  3277 * Configuration options are maintained within the theory or proof
  3278 context (with name and type bool/int/string), providing a very simple
  3279 interface to a poor-man's version of general context data.  Tools may
  3280 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3281 these values using Config.get etc.  Users may change options via an
  3282 associated attribute of the same name.  This form of context
  3283 declaration works particularly well with commands 'declare' or
  3284 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3285 very easy to avoid global references, which would not observe Isar
  3286 toplevel undo/redo and fail to work with multithreading.
  3287 
  3288 Various global ML references of Pure and HOL have been turned into
  3289 configuration options:
  3290 
  3291   Unify.search_bound		unify_search_bound
  3292   Unify.trace_bound		unify_trace_bound
  3293   Unify.trace_simp		unify_trace_simp
  3294   Unify.trace_types		unify_trace_types
  3295   Simplifier.simp_depth_limit	simp_depth_limit
  3296   Blast.depth_limit		blast_depth_limit
  3297   DatatypeProp.dtK		datatype_distinctness_limit
  3298   fast_arith_neq_limit  	fast_arith_neq_limit
  3299   fast_arith_split_limit	fast_arith_split_limit
  3300 
  3301 * Named collections of theorems may be easily installed as context
  3302 data using the functor NamedThmsFun (see also
  3303 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3304 attributes; there is also a toplevel print command.  This facility is
  3305 just a common case of general context data, which is the preferred way
  3306 for anything more complex than just a list of facts in canonical
  3307 order.
  3308 
  3309 * Isar: command 'declaration' augments a local theory by generic
  3310 declaration functions written in ML.  This enables arbitrary content
  3311 being added to the context, depending on a morphism that tells the
  3312 difference of the original declaration context wrt. the application
  3313 context encountered later on.
  3314 
  3315 * Isar: proper interfaces for simplification procedures.  Command
  3316 'simproc_setup' declares named simprocs (with match patterns, and body
  3317 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3318 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3319 
  3320 * Isar: an extra pair of brackets around attribute declarations
  3321 abbreviates a theorem reference involving an internal dummy fact,
  3322 which will be ignored later --- only the effect of the attribute on
  3323 the background context will persist.  This form of in-place
  3324 declarations is particularly useful with commands like 'declare' and
  3325 'using', for example ``have A using [[simproc a]] by simp''.
  3326 
  3327 * Isar: method "assumption" (and implicit closing of subproofs) now
  3328 takes simple non-atomic goal assumptions into account: after applying
  3329 an assumption as a rule the resulting subgoals are solved by atomic
  3330 assumption steps.  This is particularly useful to finish 'obtain'
  3331 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3332 without referring to the original premise "!!x. P x ==> thesis" in the
  3333 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3334 more permissive.
  3335 
  3336 * Isar: implicit use of prems from the Isar proof context is
  3337 considered a legacy feature.  Common applications like ``have A .''
  3338 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3339 referencing facts explicitly here improves readability and
  3340 maintainability of proof texts.
  3341 
  3342 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3343 the obtained context from the course of reasoning!  For example:
  3344 
  3345   assume "EX x y. A x & B y"   -- "any previous fact"
  3346   then guess x and y by clarify
  3347 
  3348 This technique is potentially adventurous, depending on the facts and
  3349 proof tools being involved here.
  3350 
  3351 * Isar: known facts from the proof context may be specified as literal
  3352 propositions, using ASCII back-quote syntax.  This works wherever
  3353 named facts used to be allowed so far, in proof commands, proof
  3354 methods, attributes etc.  Literal facts are retrieved from the context
  3355 according to unification of type and term parameters.  For example,
  3356 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3357 theorems in the current context, then these are valid literal facts:
  3358 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3359 
  3360 There is also a proof method "fact" which does the same composition
  3361 for explicit goal states, e.g. the following proof texts coincide with
  3362 certain special cases of literal facts:
  3363 
  3364   have "A" by fact                 ==  note `A`
  3365   have "A ==> B" by fact           ==  note `A ==> B`
  3366   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3367   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3368 
  3369 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3370 outer syntax.  Thus symbolic identifiers may be used without
  3371 additional white space in declarations like this: ``assume *: A''.
  3372 
  3373 * Isar: 'print_facts' prints all local facts of the current context,
  3374 both named and unnamed ones.
  3375 
  3376 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3377 
  3378   def x == "t" and y == "u"
  3379 
  3380 * Isar: added command 'unfolding', which is structurally similar to
  3381 'using', but affects both the goal state and facts by unfolding given
  3382 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3383 'unfolded' attribute may be replaced by first-class proof text.
  3384 
  3385 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3386 and command 'unfolding' now all support object-level equalities
  3387 (potentially conditional).  The underlying notion of rewrite rule is
  3388 analogous to the 'rule_format' attribute, but *not* that of the
  3389 Simplifier (which is usually more generous).
  3390 
  3391 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3392 premises of a theorem by n. Useful in conjunction with drule.
  3393 
  3394 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3395 method expression within a sandbox consisting of the first N
  3396 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3397 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3398 simplifies all new goals that emerge from applying rule foo to the
  3399 originally first one.
  3400 
  3401 * Isar: schematic goals are no longer restricted to higher-order
  3402 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3403 expected.
  3404 
  3405 * Isar: the conclusion of a long theorem statement is now either
  3406 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3407 (essentially a disjunction of cases with local parameters and
  3408 assumptions).  The latter allows to express general elimination rules
  3409 adequately; in this notation common elimination rules look like this:
  3410 
  3411   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3412     assumes "EX x. P x"
  3413     obtains x where "P x"
  3414 
  3415   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3416     assumes "A & B"
  3417     obtains A and B
  3418 
  3419   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3420     assumes "A | B"
  3421     obtains
  3422       A
  3423     | B
  3424 
  3425 The subsequent classical rules even refer to the formal "thesis"
  3426 explicitly:
  3427 
  3428   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3429     obtains "~ thesis"
  3430 
  3431   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3432     obtains "thesis ==> something"
  3433 
  3434 The actual proof of an 'obtains' statement is analogous to that of the
  3435 Isar proof element 'obtain', only that there may be several cases.
  3436 Optional case names may be specified in parentheses; these will be
  3437 available both in the present proof and as annotations in the
  3438 resulting rule, for later use with the 'cases' method (cf. attribute
  3439 case_names).
  3440 
  3441 * Isar: the assumptions of a long theorem statement are available as
  3442 "assms" fact in the proof context.  This is more appropriate than the
  3443 (historical) "prems", which refers to all assumptions of the current
  3444 context, including those from the target locale, proof body etc.
  3445 
  3446 * Isar: 'print_statement' prints theorems from the current theory or
  3447 proof context in long statement form, according to the syntax of a
  3448 top-level lemma.
  3449 
  3450 * Isar: 'obtain' takes an optional case name for the local context
  3451 introduction rule (default "that").
  3452 
  3453 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3454 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3455 to occur.
  3456 
  3457 * Pure: syntax "CONST name" produces a fully internalized constant
  3458 according to the current context.  This is particularly useful for
  3459 syntax translations that should refer to internal constant
  3460 representations independently of name spaces.
  3461 
  3462 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3463 instead of "FOO ". This allows multiple binder declarations to coexist
  3464 in the same context.  INCOMPATIBILITY.
  3465 
  3466 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3467 primitive that also works in a locale context (both for constants and
  3468 fixed variables). Type declaration and internal syntactic representation
  3469 of given constants retrieved from the context. Likewise, the
  3470 'no_notation' command allows to remove given syntax annotations from the
  3471 current context.
  3472 
  3473 * Isar/locales: new derived specification elements 'axiomatization',
  3474 'definition', 'abbreviation', which support type-inference, admit
  3475 object-level specifications (equality, equivalence).  See also the
  3476 isar-ref manual.  Examples:
  3477 
  3478   axiomatization
  3479     eq  (infix "===" 50) where
  3480     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3481 
  3482   definition "f x y = x + y + 1"
  3483   definition g where "g x = f x x"
  3484 
  3485   abbreviation
  3486     neq  (infix "=!=" 50) where
  3487     "x =!= y == ~ (x === y)"
  3488 
  3489 These specifications may be also used in a locale context.  Then the
  3490 constants being introduced depend on certain fixed parameters, and the
  3491 constant name is qualified by the locale base name.  An internal
  3492 abbreviation takes care for convenient input and output, making the
  3493 parameters implicit and using the original short name.  See also
  3494 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3495 entities from a monomorphic theory.
  3496 
  3497 Presently, abbreviations are only available 'in' a target locale, but
  3498 not inherited by general import expressions.  Also note that
  3499 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3500 'translations' in common applications.  The "no_abbrevs" print mode
  3501 prevents folding of abbreviations in term output.
  3502 
  3503 Concrete syntax is attached to specified constants in internal form,
  3504 independently of name spaces.  The parse tree representation is
  3505 slightly different -- use 'notation' instead of raw 'syntax', and
  3506 'translations' with explicit "CONST" markup to accommodate this.
  3507 
  3508 * Pure/Isar: unified syntax for new-style specification mechanisms
  3509 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3510 full type inference and dummy patterns ("_").  For example:
  3511 
  3512   definition "K x _ = x"
  3513 
  3514   inductive conj for A B
  3515   where "A ==> B ==> conj A B"
  3516 
  3517 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3518 the current context.  Print mode "no_abbrevs" prevents inversion of
  3519 abbreviations on output.
  3520 
  3521 * Isar/locales: improved parameter handling: use of locales "var" and
  3522 "struct" no longer necessary; - parameter renamings are no longer
  3523 required to be injective.  For example, this allows to define
  3524 endomorphisms as locale endom = homom mult mult h.
  3525 
  3526 * Isar/locales: changed the way locales with predicates are defined.
  3527 Instead of accumulating the specification, the imported expression is
  3528 now an interpretation.  INCOMPATIBILITY: different normal form of
  3529 locale expressions.  In particular, in interpretations of locales with
  3530 predicates, goals repesenting already interpreted fragments are not
  3531 removed automatically.  Use methods `intro_locales' and
  3532 `unfold_locales'; see below.
  3533 
  3534 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3535 provide backward reasoning on locales predicates.  The methods are
  3536 aware of interpretations and discharge corresponding goals.
  3537 `intro_locales' is less aggressive then `unfold_locales' and does not
  3538 unfold predicates to assumptions.
  3539 
  3540 * Isar/locales: the order in which locale fragments are accumulated
  3541 has changed.  This enables to override declarations from fragments due
  3542 to interpretations -- for example, unwanted simp rules.
  3543 
  3544 * Isar/locales: interpretation in theories and proof contexts has been
  3545 extended.  One may now specify (and prove) equations, which are
  3546 unfolded in interpreted theorems.  This is useful for replacing
  3547 defined concepts (constants depending on locale parameters) by
  3548 concepts already existing in the target context.  Example:
  3549 
  3550   interpretation partial_order ["op <= :: [int, int] => bool"]
  3551     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3552 
  3553 Typically, the constant `partial_order.less' is created by a
  3554 definition specification element in the context of locale
  3555 partial_order.
  3556 
  3557 * Method "induct": improved internal context management to support
  3558 local fixes and defines on-the-fly. Thus explicit meta-level
  3559 connectives !!  and ==> are rarely required anymore in inductive goals
  3560 (using object-logic connectives for this purpose has been long
  3561 obsolete anyway). Common proof patterns are explained in
  3562 src/HOL/Induct/Common_Patterns.thy, see also
  3563 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3564 examples.
  3565 
  3566 * Method "induct": improved handling of simultaneous goals. Instead of
  3567 introducing object-level conjunction, the statement is now split into
  3568 several conclusions, while the corresponding symbolic cases are nested
  3569 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3570 see src/HOL/Induct/Common_Patterns.thy, for example.
  3571 
  3572 * Method "induct": mutual induction rules are now specified as a list
  3573 of rule sharing the same induction cases. HOL packages usually provide
  3574 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3575 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3576 mutual induction rules differently, i.e. like this:
  3577 
  3578   (induct rule: foo_bar.inducts)
  3579   (induct set: foo bar)
  3580   (induct pred: foo bar)
  3581   (induct type: foo bar)
  3582 
  3583 The ML function ProjectRule.projections turns old-style rules into the
  3584 new format.
  3585 
  3586 * Method "coinduct": dual of induction, see
  3587 src/HOL/Library/Coinductive_List.thy for various examples.
  3588 
  3589 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3590 considered a legacy feature.
  3591 
  3592 * Attribute "symmetric" produces result with standardized schematic
  3593 variables (index 0).  Potential INCOMPATIBILITY.
  3594 
  3595 * Simplifier: by default the simplifier trace only shows top level
  3596 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3597 default. Thus there is less danger of being flooded by the trace. The
  3598 trace indicates where parts have been suppressed.
  3599   
  3600 * Provers/classical: removed obsolete classical version of elim_format
  3601 attribute; classical elim/dest rules are now treated uniformly when
  3602 manipulating the claset.
  3603 
  3604 * Provers/classical: stricter checks to ensure that supplied intro,
  3605 dest and elim rules are well-formed; dest and elim rules must have at
  3606 least one premise.
  3607 
  3608 * Provers/classical: attributes dest/elim/intro take an optional
  3609 weight argument for the rule (just as the Pure versions).  Weights are
  3610 ignored by automated tools, but determine the search order of single
  3611 rule steps.
  3612 
  3613 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3614 where the body does not mention the bound variable.  Note that dummy
  3615 patterns implicitly depend on their context of bounds, which makes
  3616 "{_. _}" match any set comprehension as expected.  Potential
  3617 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3618 constant "_idtdummy" in the binding position.
  3619 
  3620 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3621 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3622 for example "A -> B" => "Pi A (%_. B)".
  3623 
  3624 * Pure: 'class_deps' command visualizes the subclass relation, using
  3625 the graph browser tool.
  3626 
  3627 * Pure: 'print_theory' now suppresses certain internal declarations by
  3628 default; use '!' option for full details.
  3629 
  3630 
  3631 *** HOL ***
  3632 
  3633 * Method "metis" proves goals by applying the Metis general-purpose
  3634 resolution prover (see also http://gilith.com/software/metis/).
  3635 Examples are in the directory MetisExamples.  WARNING: the
  3636 Isabelle/HOL-Metis integration does not yet work properly with
  3637 multi-threading.
  3638   
  3639 * Command 'sledgehammer' invokes external automatic theorem provers as
  3640 background processes.  It generates calls to the "metis" method if
  3641 successful. These can be pasted into the proof.  Users do not have to
  3642 wait for the automatic provers to return.  WARNING: does not really
  3643 work with multi-threading.
  3644 
  3645 * New "auto_quickcheck" feature tests outermost goal statements for
  3646 potential counter-examples.  Controlled by ML references
  3647 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3648 5000 milliseconds).  Fails silently if statements is outside of
  3649 executable fragment, or any other codgenerator problem occurs.
  3650 
  3651 * New constant "undefined" with axiom "undefined x = undefined".
  3652 
  3653 * Added class "HOL.eq", allowing for code generation with polymorphic
  3654 equality.
  3655 
  3656 * Some renaming of class constants due to canonical name prefixing in
  3657 the new 'class' package:
  3658 
  3659     HOL.abs ~> HOL.abs_class.abs
  3660     HOL.divide ~> HOL.divide_class.divide
  3661     0 ~> HOL.zero_class.zero
  3662     1 ~> HOL.one_class.one
  3663     op + ~> HOL.plus_class.plus
  3664     op - ~> HOL.minus_class.minus
  3665     uminus ~> HOL.minus_class.uminus
  3666     op * ~> HOL.times_class.times
  3667     op < ~> HOL.ord_class.less
  3668     op <= > HOL.ord_class.less_eq
  3669     Nat.power ~> Power.power_class.power
  3670     Nat.size ~> Nat.size_class.size
  3671     Numeral.number_of ~> Numeral.number_class.number_of
  3672     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3673     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3674     Orderings.min ~> Orderings.ord_class.min
  3675     Orderings.max ~> Orderings.ord_class.max
  3676     Divides.op div ~> Divides.div_class.div
  3677     Divides.op mod ~> Divides.div_class.mod
  3678     Divides.op dvd ~> Divides.div_class.dvd
  3679 
  3680 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3681 
  3682 a) User-defined constants using any of the names "plus", "minus",
  3683 "times", "less" or "less_eq". The standard syntax translations for
  3684 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3685 names.
  3686 
  3687 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3688 INCOMPATIBILITY: use more specific names.
  3689 
  3690 c) Permutative equations (e.g. "a + b = b + a")
  3691 Since the change of names also changes the order of terms, permutative
  3692 rewrite rules may get applied in a different order. Experience shows
  3693 that this is rarely the case (only two adaptions in the whole Isabelle
  3694 distribution).  INCOMPATIBILITY: rewrite proofs
  3695 
  3696 d) ML code directly refering to constant names
  3697 This in general only affects hand-written proof tactics, simprocs and
  3698 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3699 Consider using @{const_name} antiquotation.
  3700 
  3701 * New class "default" with associated constant "default".
  3702 
  3703 * Function "sgn" is now overloaded and available on int, real, complex
  3704 (and other numeric types), using class "sgn".  Two possible defs of
  3705 sgn are given as equational assumptions in the classes sgn_if and
  3706 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3707 INCOMPATIBILITY.
  3708 
  3709 * Locale "partial_order" now unified with class "order" (cf. theory
  3710 Orderings), added parameter "less".  INCOMPATIBILITY.
  3711 
  3712 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3713 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3714 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3715 
  3716 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3717 changed order of proof goals in instance proofs.
  3718 
  3719 * The transitivity reasoner for partial and linear orders is set up
  3720 for classes "order" and "linorder".  Instances of the reasoner are available
  3721 in all contexts importing or interpreting the corresponding locales.
  3722 Method "order" invokes the reasoner separately; the reasoner
  3723 is also integrated with the Simplifier as a solver.  Diagnostic
  3724 command 'print_orders' shows the available instances of the reasoner
  3725 in the current context.
  3726 
  3727 * Localized monotonicity predicate in theory "Orderings"; integrated
  3728 lemmas max_of_mono and min_of_mono with this predicate.
  3729 INCOMPATIBILITY.
  3730 
  3731 * Formulation of theorem "dense" changed slightly due to integration
  3732 with new class dense_linear_order.
  3733 
  3734 * Uniform lattice theory development in HOL.
  3735 
  3736     constants "meet" and "join" now named "inf" and "sup"
  3737     constant "Meet" now named "Inf"
  3738 
  3739     classes "meet_semilorder" and "join_semilorder" now named
  3740       "lower_semilattice" and "upper_semilattice"
  3741     class "lorder" now named "lattice"
  3742     class "comp_lat" now named "complete_lattice"
  3743 
  3744     Instantiation of lattice classes allows explicit definitions
  3745     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3746 
  3747   INCOMPATIBILITY.  Theorem renames:
  3748 
  3749     meet_left_le            ~> inf_le1
  3750     meet_right_le           ~> inf_le2
  3751     join_left_le            ~> sup_ge1
  3752     join_right_le           ~> sup_ge2
  3753     meet_join_le            ~> inf_sup_ord
  3754     le_meetI                ~> le_infI
  3755     join_leI                ~> le_supI
  3756     le_meet                 ~> le_inf_iff
  3757     le_join                 ~> ge_sup_conv
  3758     meet_idempotent         ~> inf_idem
  3759     join_idempotent         ~> sup_idem
  3760     meet_comm               ~> inf_commute
  3761     join_comm               ~> sup_commute
  3762     meet_leI1               ~> le_infI1
  3763     meet_leI2               ~> le_infI2
  3764     le_joinI1               ~> le_supI1
  3765     le_joinI2               ~> le_supI2
  3766     meet_assoc              ~> inf_assoc
  3767     join_assoc              ~> sup_assoc
  3768     meet_left_comm          ~> inf_left_commute
  3769     meet_left_idempotent    ~> inf_left_idem
  3770     join_left_comm          ~> sup_left_commute
  3771     join_left_idempotent    ~> sup_left_idem
  3772     meet_aci                ~> inf_aci
  3773     join_aci                ~> sup_aci
  3774     le_def_meet             ~> le_iff_inf
  3775     le_def_join             ~> le_iff_sup
  3776     join_absorp2            ~> sup_absorb2
  3777     join_absorp1            ~> sup_absorb1
  3778     meet_absorp1            ~> inf_absorb1
  3779     meet_absorp2            ~> inf_absorb2
  3780     meet_join_absorp        ~> inf_sup_absorb
  3781     join_meet_absorp        ~> sup_inf_absorb
  3782     distrib_join_le         ~> distrib_sup_le
  3783     distrib_meet_le         ~> distrib_inf_le
  3784 
  3785     add_meet_distrib_left   ~> add_inf_distrib_left
  3786     add_join_distrib_left   ~> add_sup_distrib_left
  3787     is_join_neg_meet        ~> is_join_neg_inf
  3788     is_meet_neg_join        ~> is_meet_neg_sup
  3789     add_meet_distrib_right  ~> add_inf_distrib_right
  3790     add_join_distrib_right  ~> add_sup_distrib_right
  3791     add_meet_join_distribs  ~> add_sup_inf_distribs
  3792     join_eq_neg_meet        ~> sup_eq_neg_inf
  3793     meet_eq_neg_join        ~> inf_eq_neg_sup
  3794     add_eq_meet_join        ~> add_eq_inf_sup
  3795     meet_0_imp_0            ~> inf_0_imp_0
  3796     join_0_imp_0            ~> sup_0_imp_0
  3797     meet_0_eq_0             ~> inf_0_eq_0
  3798     join_0_eq_0             ~> sup_0_eq_0
  3799     neg_meet_eq_join        ~> neg_inf_eq_sup
  3800     neg_join_eq_meet        ~> neg_sup_eq_inf
  3801     join_eq_if              ~> sup_eq_if
  3802 
  3803     mono_meet               ~> mono_inf
  3804     mono_join               ~> mono_sup
  3805     meet_bool_eq            ~> inf_bool_eq
  3806     join_bool_eq            ~> sup_bool_eq
  3807     meet_fun_eq             ~> inf_fun_eq
  3808     join_fun_eq             ~> sup_fun_eq
  3809     meet_set_eq             ~> inf_set_eq
  3810     join_set_eq             ~> sup_set_eq
  3811     meet1_iff               ~> inf1_iff
  3812     meet2_iff               ~> inf2_iff
  3813     meet1I                  ~> inf1I
  3814     meet2I                  ~> inf2I
  3815     meet1D1                 ~> inf1D1
  3816     meet2D1                 ~> inf2D1
  3817     meet1D2                 ~> inf1D2
  3818     meet2D2                 ~> inf2D2
  3819     meet1E                  ~> inf1E
  3820     meet2E                  ~> inf2E
  3821     join1_iff               ~> sup1_iff
  3822     join2_iff               ~> sup2_iff
  3823     join1I1                 ~> sup1I1
  3824     join2I1                 ~> sup2I1
  3825     join1I1                 ~> sup1I1
  3826     join2I2                 ~> sup1I2
  3827     join1CI                 ~> sup1CI
  3828     join2CI                 ~> sup2CI
  3829     join1E                  ~> sup1E
  3830     join2E                  ~> sup2E
  3831 
  3832     is_meet_Meet            ~> is_meet_Inf
  3833     Meet_bool_def           ~> Inf_bool_def
  3834     Meet_fun_def            ~> Inf_fun_def
  3835     Meet_greatest           ~> Inf_greatest
  3836     Meet_lower              ~> Inf_lower
  3837     Meet_set_def            ~> Inf_set_def
  3838 
  3839     Sup_def                 ~> Sup_Inf
  3840     Sup_bool_eq             ~> Sup_bool_def
  3841     Sup_fun_eq              ~> Sup_fun_def
  3842     Sup_set_eq              ~> Sup_set_def
  3843 
  3844     listsp_meetI            ~> listsp_infI
  3845     listsp_meet_eq          ~> listsp_inf_eq
  3846 
  3847     meet_min                ~> inf_min
  3848     join_max                ~> sup_max
  3849 
  3850 * Added syntactic class "size"; overloaded constant "size" now has
  3851 type "'a::size ==> bool"
  3852 
  3853 * Internal reorganisation of `size' of datatypes: size theorems
  3854 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3855 simplification rules by default!); theorems "prod.size" now named
  3856 "*.size".
  3857 
  3858 * Class "div" now inherits from class "times" rather than "type".
  3859 INCOMPATIBILITY.
  3860 
  3861 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3862 Linorder etc.  have disappeared; operations defined in terms of
  3863 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3864 
  3865 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3866 
  3867 * HOL-Word: New extensive library and type for generic, fixed size
  3868 machine words, with arithemtic, bit-wise, shifting and rotating
  3869 operations, reflection into int, nat, and bool lists, automation for
  3870 linear arithmetic (by automatic reflection into nat or int), including
  3871 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3872 arithmetic type classes, supporting automatic simplification of
  3873 numerals on all operations.
  3874 
  3875 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3876 
  3877 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3878 
  3879 * Code generator library theories:
  3880   - Code_Integer represents HOL integers by big integer literals in target
  3881     languages.
  3882   - Code_Char represents HOL characters by character literals in target
  3883     languages.
  3884   - Code_Char_chr like Code_Char, but also offers treatment of character
  3885     codes; includes Code_Integer.
  3886   - Executable_Set allows to generate code for finite sets using lists.
  3887   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3888     denominator).
  3889   - Executable_Real implements a subset of real numbers, namly those
  3890     representable by rational numbers.
  3891   - Efficient_Nat implements natural numbers by integers, which in general will
  3892     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3893     includes Code_Integer.
  3894   - Code_Index provides an additional datatype index which is mapped to
  3895     target-language built-in integers.
  3896   - Code_Message provides an additional datatype message_string which is isomorphic to
  3897     strings; messages are mapped to target-language strings.
  3898 
  3899 * New package for inductive predicates
  3900 
  3901   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3902 
  3903     inductive
  3904       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3905       for z_1 :: U_1 and ... and z_n :: U_m
  3906     where
  3907       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3908     | ...
  3909 
  3910   with full support for type-inference, rather than
  3911 
  3912     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3913 
  3914     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3915     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3916 
  3917     inductive "s z_1 ... z_m"
  3918     intros
  3919       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3920       ...
  3921 
  3922   For backward compatibility, there is a wrapper allowing inductive
  3923   sets to be defined with the new package via
  3924 
  3925     inductive_set
  3926       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3927       for z_1 :: U_1 and ... and z_n :: U_m
  3928     where
  3929       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3930     | ...
  3931 
  3932   or
  3933 
  3934     inductive_set
  3935       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3936       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3937       for z_1 :: U_1 and ... and z_n :: U_m
  3938     where
  3939       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3940     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3941     | ...
  3942 
  3943   if the additional syntax "p ..." is required.
  3944 
  3945   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3946   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3947 
  3948   INCOMPATIBILITIES:
  3949 
  3950   - Since declaration and definition of inductive sets or predicates
  3951     is no longer separated, abbreviations involving the newly
  3952     introduced sets or predicates must be specified together with the
  3953     introduction rules after the 'where' keyword (see above), rather
  3954     than before the actual inductive definition.
  3955 
  3956   - The variables in induction and elimination rules are now
  3957     quantified in the order of their occurrence in the introduction
  3958     rules, rather than in alphabetical order. Since this may break
  3959     some proofs, these proofs either have to be repaired, e.g. by
  3960     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3961     statements of the form
  3962 
  3963       case (rule_i a_i_1 ... a_i_{k_i})
  3964 
  3965     or the old order of quantification has to be restored by explicitly adding
  3966     meta-level quantifiers in the introduction rules, i.e.
  3967 
  3968       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3969 
  3970   - The format of the elimination rules is now
  3971 
  3972       p z_1 ... z_m x_1 ... x_n ==>
  3973         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3974         ==> ... ==> P
  3975 
  3976     for predicates and
  3977 
  3978       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3979         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3980         ==> ... ==> P
  3981 
  3982     for sets rather than
  3983 
  3984       x : s z_1 ... z_m ==>
  3985         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3986         ==> ... ==> P
  3987 
  3988     This may require terms in goals to be expanded to n-tuples
  3989     (e.g. using case_tac or simplification with the split_paired_all
  3990     rule) before the above elimination rule is applicable.
  3991 
  3992   - The elimination or case analysis rules for (mutually) inductive
  3993     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3994     list of rules "p_1_..._p_k.elims" is no longer available.
  3995 
  3996 * New package "function"/"fun" for general recursive functions,
  3997 supporting mutual and nested recursion, definitions in local contexts,
  3998 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3999 for small examples, and the separate tutorial on the function
  4000 package. The old recdef "package" is still available as before, but
  4001 users are encouraged to use the new package.
  4002 
  4003 * Method "lexicographic_order" automatically synthesizes termination
  4004 relations as lexicographic combinations of size measures. 
  4005 
  4006 * Case-expressions allow arbitrary constructor-patterns (including
  4007 "_") and take their order into account, like in functional
  4008 programming.  Internally, this is translated into nested
  4009 case-expressions; missing cases are added and mapped to the predefined
  4010 constant "undefined". In complicated cases printing may no longer show
  4011 the original input but the internal form. Lambda-abstractions allow
  4012 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4013 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4014 variable.
  4015 
  4016 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4017 is an abbreviation for "of_nat :: nat => int". The simplification
  4018 rules for "of_nat" have been changed to work like "int" did
  4019 previously.  Potential INCOMPATIBILITY:
  4020   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4021   - of_nat_diff and of_nat_mult are no longer default simp rules
  4022 
  4023 * Method "algebra" solves polynomial equations over (semi)rings using
  4024 Groebner bases. The (semi)ring structure is defined by locales and the
  4025 tool setup depends on that generic context. Installing the method for
  4026 a specific type involves instantiating the locale and possibly adding
  4027 declarations for computation on the coefficients.  The method is
  4028 already instantiated for natural numbers and for the axiomatic class
  4029 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4030 CALCULEMUS 2007 for the general principles underlying this
  4031 architecture of context-aware proof-tools.
  4032 
  4033 * Method "ferrack" implements quantifier elimination over
  4034 special-purpose dense linear orders using locales (analogous to
  4035 "algebra"). The method is already installed for class
  4036 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4037 rat, etc.
  4038 
  4039 * Former constant "List.op @" now named "List.append".  Use ML
  4040 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4041 circumvent possible incompatibilities when working on ML level.
  4042 
  4043 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4044 
  4045 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4046 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4047 
  4048 * New syntax for Haskell-like list comprehension (input only), eg.
  4049 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4050 
  4051 * The special syntax for function "filter" has changed from [x :
  4052 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4053 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4054 
  4055 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4056 defined on nat only, as an abbreviation for [a..<Suc b]
  4057 INCOMPATIBILITY.
  4058 
  4059 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4060 
  4061 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4062 
  4063 * New lemma collection field_simps (an extension of ring_simps) for
  4064 manipulating (in)equations involving division. Multiplies with all
  4065 denominators that can be proved to be non-zero (in equations) or
  4066 positive/negative (in inequations).
  4067 
  4068 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4069 have been improved and renamed to ring_simps, group_simps and
  4070 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4071 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4072 
  4073 * Theory Library/Commutative_Ring: switched from recdef to function
  4074 package; constants add, mul, pow now curried.  Infix syntax for
  4075 algebraic operations.
  4076 
  4077 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4078 INCOMPATIBILITY.
  4079 
  4080 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4081 INCOMPATIBILITY.
  4082 
  4083 * HOL/records: generalised field-update to take a function on the
  4084 field rather than the new value: r(|A := x|) is translated to A_update
  4085 (K x) r The K-combinator that is internally used is called K_record.
  4086 INCOMPATIBILITY: Usage of the plain update functions has to be
  4087 adapted.
  4088  
  4089 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4090 * x = 0, which are required for a semiring.  Richer structures do not
  4091 inherit from semiring_0 anymore, because this property is a theorem
  4092 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4093 there is more to prove, but this is mostly trivial.
  4094 
  4095 * Class "recpower" is generalized to arbitrary monoids, not just
  4096 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4097 commutativity or semiring properties additionally.
  4098 
  4099 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4100 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4101 better use 'abbreviation'.
  4102 
  4103 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4104 
  4105 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4106 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4107 significant changes for setting up numeral syntax for types:
  4108   - New constants Numeral.pred and Numeral.succ instead
  4109       of former Numeral.bin_pred and Numeral.bin_succ.
  4110   - Use integer operations instead of bin_add, bin_mult and so on.
  4111   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4112   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4113 
  4114 See src/HOL/Integ/IntArith.thy for an example setup.
  4115 
  4116 * Command 'normal_form' computes the normal form of a term that may
  4117 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4118 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4119 heavy-duty computations because the functions are compiled to ML
  4120 first.  Correspondingly, a method "normalization" is provided.  See
  4121 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4122 
  4123 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4124 25 like -->); output depends on the "iff" print_mode, the default is
  4125 "A = B" (with priority 50).
  4126 
  4127 * Relations less (<) and less_eq (<=) are also available on type bool.
  4128 Modified syntax to disallow nesting without explicit parentheses,
  4129 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4130 INCOMPATIBILITY.
  4131 
  4132 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4133 
  4134 * Relation composition operator "op O" now has precedence 75 and binds
  4135 stronger than union and intersection. INCOMPATIBILITY.
  4136 
  4137 * The old set interval syntax "{m..n(}" (and relatives) has been
  4138 removed.  Use "{m..<n}" (and relatives) instead.
  4139 
  4140 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4141 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4142 ``declare [[simproc del: neq]]''.
  4143 
  4144 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4145 True/False.
  4146 
  4147 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4148 
  4149 * Theorem setsum_mult renamed to setsum_right_distrib.
  4150 
  4151 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4152 ``rule'' method.
  4153 
  4154 * Reimplemented methods "sat" and "satx", with several improvements:
  4155 goals no longer need to be stated as "<prems> ==> False", equivalences
  4156 (i.e. "=" on type bool) are handled, variable names of the form
  4157 "lit_<n>" are no longer reserved, significant speedup.
  4158 
  4159 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4160 zChaff is still supported as well.
  4161 
  4162 * 'inductive' and 'datatype': provide projections of mutual rules,
  4163 bundled as foo_bar.inducts;
  4164 
  4165 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4166 Library.
  4167 
  4168 * Library: moved theory Accessible_Part to main HOL.
  4169 
  4170 * Library: added theory Coinductive_List of potentially infinite lists
  4171 as greatest fixed-point.
  4172 
  4173 * Library: added theory AssocList which implements (finite) maps as
  4174 association lists.
  4175 
  4176 * Method "evaluation" solves goals (i.e. a boolean expression)
  4177 efficiently by compiling it to ML.  The goal is "proved" (via an
  4178 oracle) if it evaluates to True.
  4179 
  4180 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4181 also when invoked by the simplifier.  This results in the Simplifier
  4182 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4183 Configuration option fast_arith_split_limit=0 recovers the old
  4184 behavior.
  4185 
  4186 * Support for hex (0x20) and binary (0b1001) numerals.
  4187 
  4188 * New method: reify eqs (t), where eqs are equations for an
  4189 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4190 parameter, computes a term s::'b and a list xs::'a list and proves the
  4191 theorem I xs s = t. This is also known as reification or quoting. The
  4192 resulting theorem is applied to the subgoal to substitute t with I xs
  4193 s.  If t is omitted, the subgoal itself is reified.
  4194 
  4195 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4196 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4197 where f is supposed to be a computable function (in the sense of code
  4198 generattion). The method uses reify to compute s and xs as above then
  4199 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4200 r and finally gets the theorem t = r, which is again applied to the
  4201 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4202 
  4203 * Reflection: Automatic reification now handels binding, an example is
  4204 available in src/HOL/ex/ReflectionEx.thy
  4205 
  4206 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4207 command 'statespace' that is similar to 'record', but introduces an
  4208 abstract specification based on the locale infrastructure instead of
  4209 HOL types.  This leads to extra flexibility in composing state spaces,
  4210 in particular multiple inheritance and renaming of components.
  4211 
  4212 
  4213 *** HOL-Complex ***
  4214 
  4215 * Hyperreal: Functions root and sqrt are now defined on negative real
  4216 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4217 Nonnegativity side conditions have been removed from many lemmas, so
  4218 that more subgoals may now be solved by simplification; potential
  4219 INCOMPATIBILITY.
  4220 
  4221 * Real: new type classes formalize real normed vector spaces and
  4222 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4223 and norm :: 'a => real.
  4224 
  4225 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4226 reals into other types. The overloaded constant Reals :: 'a set is now
  4227 defined as range of_real; potential INCOMPATIBILITY.
  4228 
  4229 * Real: proper support for ML code generation, including 'quickcheck'.
  4230 Reals are implemented as arbitrary precision rationals.
  4231 
  4232 * Hyperreal: Several constants that previously worked only for the
  4233 reals have been generalized, so they now work over arbitrary vector
  4234 spaces. Type annotations may need to be added in some cases; potential
  4235 INCOMPATIBILITY.
  4236 
  4237   Infinitesimal  :: ('a::real_normed_vector) star set
  4238   HFinite        :: ('a::real_normed_vector) star set
  4239   HInfinite      :: ('a::real_normed_vector) star set
  4240   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4241   monad          :: ('a::real_normed_vector) star => 'a star set
  4242   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4243   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4244   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4245   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4246   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4247   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4248   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4249   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4250   sgn            :: 'a::real_normed_vector => 'a
  4251   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4252 
  4253 * Complex: Some complex-specific constants are now abbreviations for
  4254 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4255 hnorm.  Other constants have been entirely removed in favor of the
  4256 polymorphic versions (INCOMPATIBILITY):
  4257 
  4258   approx        <-- capprox
  4259   HFinite       <-- CFinite
  4260   HInfinite     <-- CInfinite
  4261   Infinitesimal <-- CInfinitesimal
  4262   monad         <-- cmonad
  4263   galaxy        <-- cgalaxy
  4264   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4265   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4266   (ns)deriv     <-- (ns)cderiv
  4267 
  4268 
  4269 *** HOL-Algebra ***
  4270 
  4271 * Formalisation of ideals and the quotient construction over rings.
  4272 
  4273 * Order and lattice theory no longer based on records.
  4274 INCOMPATIBILITY.
  4275 
  4276 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4277 greatest_closed.  INCOMPATIBILITY.
  4278 
  4279 * Method algebra is now set up via an attribute.  For examples see
  4280 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4281 of algebraic structures.
  4282 
  4283 * Renamed theory CRing to Ring.
  4284 
  4285 
  4286 *** HOL-Nominal ***
  4287 
  4288 * Substantial, yet incomplete support for nominal datatypes (binding
  4289 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4290 src/HOL/Nominal/Examples.  Prospective users should consult
  4291 http://isabelle.in.tum.de/nominal/
  4292 
  4293 
  4294 *** ML ***
  4295 
  4296 * ML basics: just one true type int, which coincides with IntInf.int
  4297 (even on SML/NJ).
  4298 
  4299 * ML within Isar: antiquotations allow to embed statically-checked
  4300 formal entities in the source, referring to the context available at
  4301 compile-time.  For example:
  4302 
  4303 ML {* @{sort "{zero,one}"} *}
  4304 ML {* @{typ "'a => 'b"} *}
  4305 ML {* @{term "%x. x"} *}
  4306 ML {* @{prop "x == y"} *}
  4307 ML {* @{ctyp "'a => 'b"} *}
  4308 ML {* @{cterm "%x. x"} *}
  4309 ML {* @{cprop "x == y"} *}
  4310 ML {* @{thm asm_rl} *}
  4311 ML {* @{thms asm_rl} *}
  4312 ML {* @{type_name c} *}
  4313 ML {* @{type_syntax c} *}
  4314 ML {* @{const_name c} *}
  4315 ML {* @{const_syntax c} *}
  4316 ML {* @{context} *}
  4317 ML {* @{theory} *}
  4318 ML {* @{theory Pure} *}
  4319 ML {* @{theory_ref} *}
  4320 ML {* @{theory_ref Pure} *}
  4321 ML {* @{simpset} *}
  4322 ML {* @{claset} *}
  4323 ML {* @{clasimpset} *}
  4324 
  4325 The same works for sources being ``used'' within an Isar context.
  4326 
  4327 * ML in Isar: improved error reporting; extra verbosity with
  4328 ML_Context.trace enabled.
  4329 
  4330 * Pure/General/table.ML: the join operations now works via exceptions
  4331 DUP/SAME instead of type option. This is simpler in simple cases, and
  4332 admits slightly more efficient complex applications.
  4333 
  4334 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4335 use Context.generic instead of just theory.
  4336 
  4337 * Pure: datatype Context.generic joins theory/Proof.context and
  4338 provides some facilities for code that works in either kind of
  4339 context, notably GenericDataFun for uniform theory and proof data.
  4340 
  4341 * Pure: simplified internal attribute type, which is now always
  4342 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4343 local (Proof.context) attributes have been discontinued, while
  4344 minimizing code duplication. Thm.rule_attribute and
  4345 Thm.declaration_attribute build canonical attributes; see also structure
  4346 Context for further operations on Context.generic, notably
  4347 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4348 declarations and definitions.
  4349 
  4350 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4351 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4352 init only required for impure data. INCOMPATIBILITY: empty really need
  4353 to be empty (no dependencies on theory content!)
  4354 
  4355 * Pure/kernel: consts certification ignores sort constraints given in
  4356 signature declarations. (This information is not relevant to the
  4357 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4358 potential INCOMPATIBILITY.
  4359 
  4360 * Pure: axiomatic type classes are now purely definitional, with
  4361 explicit proofs of class axioms and super class relations performed
  4362 internally. See Pure/axclass.ML for the main internal interfaces --
  4363 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4364 AxClass.axiomatize_class/classrel/arity supersede
  4365 Sign.add_classes/classrel/arities.
  4366 
  4367 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4368 global/local versions on theory vs. Proof.context have been
  4369 discontinued; Attrib.syntax and Method.syntax have been adapted
  4370 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4371 attributes, methods, etc.
  4372 
  4373 * Pure: several functions of signature "... -> theory -> theory * ..."
  4374 have been reoriented to "... -> theory -> ... * theory" in order to
  4375 allow natural usage in combination with the ||>, ||>>, |-> and
  4376 fold_map combinators.
  4377 
  4378 * Pure: official theorem names (closed derivations) and additional
  4379 comments (tags) are now strictly separate.  Name hints -- which are
  4380 maintained as tags -- may be attached any time without affecting the
  4381 derivation.
  4382 
  4383 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4384 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4385 achieve the old behaviour.
  4386 
  4387 * Pure: the "Goal" constant is now called "prop", supporting a
  4388 slightly more general idea of ``protecting'' meta-level rule
  4389 statements.
  4390 
  4391 * Pure: Logic.(un)varify only works in a global context, which is now
  4392 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4393 Logic.legacy_(un)varify as temporary workaround.
  4394 
  4395 * Pure: structure Name provides scalable operations for generating
  4396 internal variable names, notably Name.variants etc.  This replaces
  4397 some popular functions from term.ML:
  4398 
  4399   Term.variant		->  Name.variant
  4400   Term.variantlist	->  Name.variant_list
  4401   Term.invent_names	->  Name.invent_list
  4402 
  4403 Note that low-level renaming rarely occurs in new code -- operations
  4404 from structure Variable are used instead (see below).
  4405 
  4406 * Pure: structure Variable provides fundamental operations for proper
  4407 treatment of fixed/schematic variables in a context.  For example,
  4408 Variable.import introduces fixes for schematics of given facts and
  4409 Variable.export reverses the effect (up to renaming) -- this replaces
  4410 various freeze_thaw operations.
  4411 
  4412 * Pure: structure Goal provides simple interfaces for
  4413 init/conclude/finish and tactical prove operations (replacing former
  4414 Tactic.prove).  Goal.prove is the canonical way to prove results
  4415 within a given context; Goal.prove_global is a degraded version for
  4416 theory level goals, including a global Drule.standard.  Note that
  4417 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4418 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4419 in a locale context).
  4420 
  4421 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4422 and type checking (Syntax.check_term etc.), with common combinations
  4423 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4424 which are considered legacy and await removal.
  4425 
  4426 * Pure/Syntax: generic interfaces for type unchecking
  4427 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4428 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4429 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4430 available for convenience, but refer to the very same operations using
  4431 a mere theory instead of a full context.
  4432 
  4433 * Isar: simplified treatment of user-level errors, using exception
  4434 ERROR of string uniformly.  Function error now merely raises ERROR,
  4435 without any side effect on output channels.  The Isar toplevel takes
  4436 care of proper display of ERROR exceptions.  ML code may use plain
  4437 handle/can/try; cat_error may be used to concatenate errors like this:
  4438 
  4439   ... handle ERROR msg => cat_error msg "..."
  4440 
  4441 Toplevel ML code (run directly or through the Isar toplevel) may be
  4442 embedded into the Isar toplevel with exception display/debug like
  4443 this:
  4444 
  4445   Isar.toplevel (fn () => ...)
  4446 
  4447 INCOMPATIBILITY, removed special transform_error facilities, removed
  4448 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4449 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4450 -- use plain ERROR instead.
  4451 
  4452 * Isar: theory setup now has type (theory -> theory), instead of a
  4453 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4454 
  4455 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4456 ProofContext.debug/verbose flags.
  4457 
  4458 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4459 theory before entering a proof state.  Transactions now always see a
  4460 quasi-functional intermediate checkpoint, both in interactive and
  4461 batch mode.
  4462 
  4463 * Isar: simplified interfaces for outer syntax.  Renamed
  4464 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4465 OuterSyntax.add_parsers -- this functionality is now included in
  4466 OuterSyntax.command etc.  INCOMPATIBILITY.
  4467 
  4468 * Simplifier: the simpset of a running simplification process now
  4469 contains a proof context (cf. Simplifier.the_context), which is the
  4470 very context that the initial simpset has been retrieved from (by
  4471 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4472 (solver, looper etc.) may depend on arbitrary proof data.
  4473 
  4474 * Simplifier.inherit_context inherits the proof context (plus the
  4475 local bounds) of the current simplification process; any simproc
  4476 etc. that calls the Simplifier recursively should do this!  Removed
  4477 former Simplifier.inherit_bounds, which is already included here --
  4478 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4479 specify an explicit context using Simplifier.context/theory_context.
  4480 
  4481 * Simplifier/Classical Reasoner: more abstract interfaces
  4482 change_simpset/claset for modifying the simpset/claset reference of a
  4483 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4484 INCOMPATIBILITY.
  4485 
  4486 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4487 "Trueprop" etc.
  4488 
  4489 
  4490 *** System ***
  4491 
  4492 * settings: the default heap location within ISABELLE_HOME_USER now
  4493 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4494 Isabelle installations.
  4495 
  4496 * isabelle-process: option -S (secure mode) disables some critical
  4497 operations, notably runtime compilation and evaluation of ML source
  4498 code.
  4499 
  4500 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4501 
  4502 * Support for parallel execution, using native multicore support of
  4503 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4504 independent theories, according to the given theory header
  4505 specifications. The maximum number of worker threads is specified via
  4506 usedir option -M or the "max-threads" setting in Proof General. A
  4507 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4508 to 6 on a 8-core machine.  User-code needs to observe certain
  4509 guidelines for thread-safe programming, see appendix A in the Isar
  4510 Implementation manual.
  4511 
  4512 
  4513 
  4514 New in Isabelle2005 (October 2005)
  4515 ----------------------------------
  4516 
  4517 *** General ***
  4518 
  4519 * Theory headers: the new header syntax for Isar theories is
  4520 
  4521   theory <name>
  4522   imports <theory1> ... <theoryN>
  4523   uses <file1> ... <fileM>
  4524   begin
  4525 
  4526 where the 'uses' part is optional.  The previous syntax
  4527 
  4528   theory <name> = <theory1> + ... + <theoryN>:
  4529 
  4530 will disappear in the next release.  Use isatool fixheaders to convert
  4531 existing theory files.  Note that there is no change in ancient
  4532 non-Isar theories now, but these will disappear soon.
  4533 
  4534 * Theory loader: parent theories can now also be referred to via
  4535 relative and absolute paths.
  4536 
  4537 * Command 'find_theorems' searches for a list of criteria instead of a
  4538 list of constants. Known criteria are: intro, elim, dest, name:string,
  4539 simp:term, and any term. Criteria can be preceded by '-' to select
  4540 theorems that do not match. Intro, elim, dest select theorems that
  4541 match the current goal, name:s selects theorems whose fully qualified
  4542 name contain s, and simp:term selects all simplification rules whose
  4543 lhs match term.  Any other term is interpreted as pattern and selects
  4544 all theorems matching the pattern. Available in ProofGeneral under
  4545 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4546 
  4547   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4548 
  4549 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4550 matching the current goal as introduction rule and not having "HOL."
  4551 in their name (i.e. not being defined in theory HOL).
  4552 
  4553 * Command 'thms_containing' has been discontinued in favour of
  4554 'find_theorems'; INCOMPATIBILITY.
  4555 
  4556 * Communication with Proof General is now 8bit clean, which means that
  4557 Unicode text in UTF-8 encoding may be used within theory texts (both
  4558 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4559 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4560 
  4561   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4562   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4563 
  4564 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4565 Classical Reasoner.  Typical big applications run around 2 times
  4566 faster.
  4567 
  4568 
  4569 *** Document preparation ***
  4570 
  4571 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4572 of raw sources.  Only those symbols that do not require additional
  4573 LaTeX packages (depending on comments in isabellesym.sty) are
  4574 displayed properly, everything else is left verbatim.  isatool display
  4575 and isatool print are used as front ends (these are subject to the
  4576 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4577 
  4578 * Command tags control specific markup of certain regions of text,
  4579 notably folding and hiding.  Predefined tags include "theory" (for
  4580 theory begin and end), "proof" for proof commands, and "ML" for
  4581 commands involving ML code; the additional tags "visible" and
  4582 "invisible" are unused by default.  Users may give explicit tag
  4583 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4584 interpretation of tags is determined by the LaTeX job during document
  4585 preparation: see option -V of isatool usedir, or options -n and -t of
  4586 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4587 \isadroptag.
  4588 
  4589 Several document versions may be produced at the same time via isatool
  4590 usedir (the generated index.html will link all of them).  Typical
  4591 specifications include ''-V document=theory,proof,ML'' to present
  4592 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4593 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4594 these parts without any formal replacement text.  The Isabelle site
  4595 default settings produce ''document'' and ''outline'' versions as
  4596 specified above.
  4597 
  4598 * Several new antiquotations:
  4599 
  4600   @{term_type term} prints a term with its type annotated;
  4601 
  4602   @{typeof term} prints the type of a term;
  4603 
  4604   @{const const} is the same as @{term const}, but checks that the
  4605   argument is a known logical constant;
  4606 
  4607   @{term_style style term} and @{thm_style style thm} print a term or
  4608   theorem applying a "style" to it
  4609 
  4610   @{ML text}
  4611 
  4612 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4613 definitions, equations, inequations etc., 'concl' printing only the
  4614 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4615 to print the specified premise.  TermStyle.add_style provides an ML
  4616 interface for introducing further styles.  See also the "LaTeX Sugar"
  4617 document practical applications.  The ML antiquotation prints
  4618 type-checked ML expressions verbatim.
  4619 
  4620 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4621 and 'text' support optional locale specification '(in loc)', which
  4622 specifies the default context for interpreting antiquotations.  For
  4623 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4624 
  4625 * Option 'locale=NAME' of antiquotations specifies an alternative
  4626 context interpreting the subsequent argument.  For example: @{thm
  4627 [locale=lattice] inf_assoc}.
  4628 
  4629 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4630 a proof context.
  4631 
  4632 * Proper output of antiquotations for theory commands involving a
  4633 proof context (such as 'locale' or 'theorem (in loc) ...').
  4634 
  4635 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4636 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4637 
  4638 * isatool usedir: new option -C (default true) controls whether option
  4639 -D should include a copy of the original document directory; -C false
  4640 prevents unwanted effects such as copying of administrative CVS data.
  4641 
  4642 
  4643 *** Pure ***
  4644 
  4645 * Considerably improved version of 'constdefs' command.  Now performs
  4646 automatic type-inference of declared constants; additional support for
  4647 local structure declarations (cf. locales and HOL records), see also
  4648 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4649 sequential dependencies of definitions within a single 'constdefs'
  4650 section; moreover, the declared name needs to be an identifier.  If
  4651 all fails, consider to fall back on 'consts' and 'defs' separately.
  4652 
  4653 * Improved indexed syntax and implicit structures.  First of all,
  4654 indexed syntax provides a notational device for subscripted
  4655 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4656 expressions.  Secondly, in a local context with structure
  4657 declarations, number indexes \<^sub>n or the empty index (default
  4658 number 1) refer to a certain fixed variable implicitly; option
  4659 show_structs controls printing of implicit structures.  Typical
  4660 applications of these concepts involve record types and locales.
  4661 
  4662 * New command 'no_syntax' removes grammar declarations (and
  4663 translations) resulting from the given syntax specification, which is
  4664 interpreted in the same manner as for the 'syntax' command.
  4665 
  4666 * 'Advanced' translation functions (parse_translation etc.) may depend
  4667 on the signature of the theory context being presently used for
  4668 parsing/printing, see also isar-ref manual.
  4669 
  4670 * Improved 'oracle' command provides a type-safe interface to turn an
  4671 ML expression of type theory -> T -> term into a primitive rule of
  4672 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4673 is already included here); see also FOL/ex/IffExample.thy;
  4674 INCOMPATIBILITY.
  4675 
  4676 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4677 before); "cI" is no longer bound, use "c.intro" instead.
  4678 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4679 axclasses vs. locales.
  4680 
  4681 * Improved internal renaming of symbolic identifiers -- attach primes
  4682 instead of base 26 numbers.
  4683 
  4684 * New flag show_question_marks controls printing of leading question
  4685 marks in schematic variable names.
  4686 
  4687 * In schematic variable names, *any* symbol following \<^isub> or
  4688 \<^isup> is now treated as part of the base name.  For example, the
  4689 following works without printing of awkward ".0" indexes:
  4690 
  4691   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4692     by simp
  4693 
  4694 * Inner syntax includes (*(*nested*) comments*).
  4695 
  4696 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4697 annotations as "(00...)".
  4698 
  4699 * Clear separation of logical types and nonterminals, where the latter
  4700 may only occur in 'syntax' specifications or type abbreviations.
  4701 Before that distinction was only partially implemented via type class
  4702 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4703 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4704 exotic syntax specifications may require further adaption
  4705 (e.g. Cube/Cube.thy).
  4706 
  4707 * Removed obsolete type class "logic", use the top sort {} instead.
  4708 Note that non-logical types should be declared as 'nonterminals'
  4709 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4710 specifications.
  4711 
  4712 * Attributes 'induct' and 'cases': type or set names may now be
  4713 locally fixed variables as well.
  4714 
  4715 * Simplifier: can now control the depth to which conditional rewriting
  4716 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4717 Limit.
  4718 
  4719 * Simplifier: simplification procedures may now take the current
  4720 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4721 interface), which is very useful for calling the Simplifier
  4722 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4723 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4724 low-level mk_simproc no longer applies Logic.varify internally, to
  4725 allow for use in a context of fixed variables.
  4726 
  4727 * thin_tac now works even if the assumption being deleted contains !!
  4728 or ==>.  More generally, erule now works even if the major premise of
  4729 the elimination rule contains !! or ==>.
  4730 
  4731 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4732 
  4733 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4734 from Pure, which contains all common declarations already.  Both
  4735 theories are defined via plain Isabelle/Isar .thy files.
  4736 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4737 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4738 use isatool fixcpure to adapt your theory and ML sources.
  4739 
  4740 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4741 selections of theorems in named facts via index ranges.
  4742 
  4743 * 'print_theorems': in theory mode, really print the difference
  4744 wrt. the last state (works for interactive theory development only),
  4745 in proof mode print all local facts (cf. 'print_facts');
  4746 
  4747 * 'hide': option '(open)' hides only base names.
  4748 
  4749 * More efficient treatment of intermediate checkpoints in interactive
  4750 theory development.
  4751 
  4752 * Code generator is now invoked via code_module (incremental code
  4753 generation) and code_library (modular code generation, ML structures
  4754 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4755 must be quoted when used as identifiers.
  4756 
  4757 * New 'value' command for reading, evaluating and printing terms using
  4758 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4759 quoted when used as identifier.
  4760 
  4761 
  4762 *** Locales ***
  4763 
  4764 * New commands for the interpretation of locale expressions in
  4765 theories (1), locales (2) and proof contexts (3).  These generate
  4766 proof obligations from the expression specification.  After the
  4767 obligations have been discharged, theorems of the expression are added
  4768 to the theory, target locale or proof context.  The synopsis of the
  4769 commands is a follows:
  4770 
  4771   (1) interpretation expr inst
  4772   (2) interpretation target < expr
  4773   (3) interpret expr inst
  4774 
  4775 Interpretation in theories and proof contexts require a parameter
  4776 instantiation of terms from the current context.  This is applied to
  4777 specifications and theorems of the interpreted expression.
  4778 Interpretation in locales only permits parameter renaming through the
  4779 locale expression.  Interpretation is smart in that interpretations
  4780 that are active already do not occur in proof obligations, neither are
  4781 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4782 inspect active interpretations of a particular locale.  For details,
  4783 see the Isar Reference manual.  Examples can be found in
  4784 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4785 
  4786 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4787 'interpret' instead.
  4788 
  4789 * New context element 'constrains' for adding type constraints to
  4790 parameters.
  4791 
  4792 * Context expressions: renaming of parameters with syntax
  4793 redeclaration.
  4794 
  4795 * Locale declaration: 'includes' disallowed.
  4796 
  4797 * Proper static binding of attribute syntax -- i.e. types / terms /
  4798 facts mentioned as arguments are always those of the locale definition
  4799 context, independently of the context of later invocations.  Moreover,
  4800 locale operations (renaming and type / term instantiation) are applied
  4801 to attribute arguments as expected.
  4802 
  4803 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4804 actual attributes; rare situations may require Attrib.attribute to
  4805 embed those attributes into Attrib.src that lack concrete syntax.
  4806 Attribute implementations need to cooperate properly with the static
  4807 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4808 Attrib.XXX_thm etc. already do the right thing without further
  4809 intervention.  Only unusual applications -- such as "where" or "of"
  4810 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4811 on the context and the facts involved -- may have to assign parsed
  4812 values to argument tokens explicitly.
  4813 
  4814 * Changed parameter management in theorem generation for long goal
  4815 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4816 theorem statement in rare situations.
  4817 
  4818 * Locale inspection command 'print_locale' omits notes elements.  Use
  4819 'print_locale!' to have them included in the output.
  4820 
  4821 
  4822 *** Provers ***
  4823 
  4824 * Provers/hypsubst.ML: improved version of the subst method, for
  4825 single-step rewriting: it now works in bound variable contexts. New is
  4826 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4827 rewrite a different subterm than the original subst method, which is
  4828 still available as 'simplesubst'.
  4829 
  4830 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4831 and quasi orders.
  4832 
  4833 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4834 reflexive-transitive closure of relations.
  4835 
  4836 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4837 limit (previously hard-coded with a value of 20) user-definable.
  4838 
  4839 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4840 is peformed already.  Object-logics merely need to finish their
  4841 initial simpset configuration as before.  INCOMPATIBILITY.
  4842 
  4843 
  4844 *** HOL ***
  4845 
  4846 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4847 
  4848   syntax (epsilon)
  4849     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4850 
  4851 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4852 and x-symbol; use option '-m epsilon' to get it actually printed.
  4853 Moreover, the mathematically important symbolic identifier \<epsilon>
  4854 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4855 
  4856 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4857 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4858 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4859 support corresponding Isar calculations.
  4860 
  4861 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4862 instead of ":".
  4863 
  4864 * theory SetInterval: changed the syntax for open intervals:
  4865 
  4866   Old       New
  4867   {..n(}    {..<n}
  4868   {)n..}    {n<..}
  4869   {m..n(}   {m..<n}
  4870   {)m..n}   {m<..n}
  4871   {)m..n(}  {m<..<n}
  4872 
  4873 The old syntax is still supported but will disappear in the next
  4874 release.  For conversion use the following Emacs search and replace
  4875 patterns (these are not perfect but work quite well):
  4876 
  4877   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4878   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4879 
  4880 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4881 equalities in commutative rings; method 'algebra' provides a generic
  4882 interface.
  4883 
  4884 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4885 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4886 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4887 be a tuple pattern.
  4888 
  4889 Some new syntax forms are available:
  4890 
  4891   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4892   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4893   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4894   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4895 
  4896 The latter form "\<Sum>x < k. e" used to be based on a separate
  4897 function "Summation", which has been discontinued.
  4898 
  4899 * theory Finite_Set: in structured induction proofs, the insert case
  4900 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4901 (insert F x)'.
  4902 
  4903 * The 'refute' command has been extended to support a much larger
  4904 fragment of HOL, including axiomatic type classes, constdefs and
  4905 typedefs, inductive datatypes and recursion.
  4906 
  4907 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4908 Requires zChaff with proof generation to be installed.  See
  4909 HOL/ex/SAT_Examples.thy for examples.
  4910 
  4911 * Datatype induction via method 'induct' now preserves the name of the
  4912 induction variable. For example, when proving P(xs::'a list) by
  4913 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4914 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4915 in unstructured proof scripts.
  4916 
  4917 * Reworked implementation of records.  Improved scalability for
  4918 records with many fields, avoiding performance problems for type
  4919 inference. Records are no longer composed of nested field types, but
  4920 of nested extension types. Therefore the record type only grows linear
  4921 in the number of extensions and not in the number of fields.  The
  4922 top-level (users) view on records is preserved.  Potential
  4923 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4924 old record representation. The type generated for a record is called
  4925 <record_name>_ext_type.
  4926 
  4927 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4928 proofs triggered by a record definition or a simproc (if
  4929 quick_and_dirty is enabled).  Definitions of large records can take
  4930 quite long.
  4931 
  4932 New simproc record_upd_simproc for simplification of multiple record
  4933 updates enabled by default.  Moreover, trivial updates are also
  4934 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4935 occasionally, since simplification is more powerful by default.
  4936 
  4937 * typedef: proper support for polymorphic sets, which contain extra
  4938 type-variables in the term.
  4939 
  4940 * Simplifier: automatically reasons about transitivity chains
  4941 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4942 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4943 old proofs break occasionally as simplification may now solve more
  4944 goals than previously.
  4945 
  4946 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4947 present.  Works for all partial orders (class "order"), in particular
  4948 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4949 just like y <= x.
  4950 
  4951 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4952 bound variable or a constant then the let is unfolded.  Otherwise
  4953 first a is simplified to b, and then f b is simplified to g. If
  4954 possible we abstract b from g arriving at "let x = b in h x",
  4955 otherwise we unfold the let and arrive at g.  The simproc can be
  4956 enabled/disabled by the reference use_let_simproc.  Potential
  4957 INCOMPATIBILITY since simplification is more powerful by default.
  4958 
  4959 * Classical reasoning: the meson method now accepts theorems as arguments.
  4960 
  4961 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4962 jobs to provide advice on the provability of subgoals.
  4963 
  4964 * Theory OrderedGroup and Ring_and_Field: various additions and
  4965 improvements to faciliate calculations involving equalities and
  4966 inequalities.
  4967 
  4968 The following theorems have been eliminated or modified
  4969 (INCOMPATIBILITY):
  4970 
  4971   abs_eq             now named abs_of_nonneg
  4972   abs_of_ge_0        now named abs_of_nonneg
  4973   abs_minus_eq       now named abs_of_nonpos
  4974   imp_abs_id         now named abs_of_nonneg
  4975   imp_abs_neg_id     now named abs_of_nonpos
  4976   mult_pos           now named mult_pos_pos
  4977   mult_pos_le        now named mult_nonneg_nonneg
  4978   mult_pos_neg_le    now named mult_nonneg_nonpos
  4979   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4980   mult_neg           now named mult_neg_neg
  4981   mult_neg_le        now named mult_nonpos_nonpos
  4982 
  4983 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4984      
  4985      zero_le_square
  4986      not_square_less_zero 
  4987 
  4988   The following lemmas have been deleted from Real/RealPow:
  4989   
  4990      realpow_zero_zero
  4991      realpow_two
  4992      realpow_less
  4993      zero_le_power
  4994      realpow_two_le
  4995      abs_realpow_two
  4996      realpow_two_abs     
  4997 
  4998 * Theory Parity: added rules for simplifying exponents.
  4999 
  5000 * Theory List:
  5001 
  5002 The following theorems have been eliminated or modified
  5003 (INCOMPATIBILITY):
  5004 
  5005   list_all_Nil       now named list_all.simps(1)
  5006   list_all_Cons      now named list_all.simps(2)
  5007   list_all_conv      now named list_all_iff
  5008   set_mem_eq         now named mem_iff
  5009 
  5010 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5011 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5012 
  5013 
  5014 *** HOL-Complex ***
  5015 
  5016 * Theory RealDef: better support for embedding natural numbers and
  5017 integers in the reals.
  5018 
  5019 The following theorems have been eliminated or modified
  5020 (INCOMPATIBILITY):
  5021 
  5022   exp_ge_add_one_self  now requires no hypotheses
  5023   real_of_int_add      reversed direction of equality (use [symmetric])
  5024   real_of_int_minus    reversed direction of equality (use [symmetric])
  5025   real_of_int_diff     reversed direction of equality (use [symmetric])
  5026   real_of_int_mult     reversed direction of equality (use [symmetric])
  5027 
  5028 * Theory RComplete: expanded support for floor and ceiling functions.
  5029 
  5030 * Theory Ln is new, with properties of the natural logarithm
  5031 
  5032 * Hyperreal: There is a new type constructor "star" for making
  5033 nonstandard types.  The old type names are now type synonyms:
  5034 
  5035   hypreal = real star
  5036   hypnat = nat star
  5037   hcomplex = complex star
  5038 
  5039 * Hyperreal: Many groups of similarly-defined constants have been
  5040 replaced by polymorphic versions (INCOMPATIBILITY):
  5041 
  5042   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5043 
  5044   starset      <-- starsetNat, starsetC
  5045   *s*          <-- *sNat*, *sc*
  5046   starset_n    <-- starsetNat_n, starsetC_n
  5047   *sn*         <-- *sNatn*, *scn*
  5048   InternalSets <-- InternalNatSets, InternalCSets
  5049 
  5050   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5051   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5052   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5053   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5054   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5055 
  5056 * Hyperreal: Many type-specific theorems have been removed in favor of
  5057 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5058 
  5059   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5060   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5061   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5062   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5063   right_minus <-- hypreal_add_minus
  5064   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5065   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5066   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5067   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5068   mult_1_right <-- hcomplex_mult_one_right
  5069   mult_zero_left <-- hcomplex_mult_zero_left
  5070   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5071   right_distrib <-- hypnat_add_mult_distrib2
  5072   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5073   right_inverse <-- hypreal_mult_inverse
  5074   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5075   order_refl <-- {hypreal,hypnat}_le_refl
  5076   order_trans <-- {hypreal,hypnat}_le_trans
  5077   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5078   order_less_le <-- {hypreal,hypnat}_less_le
  5079   linorder_linear <-- {hypreal,hypnat}_le_linear
  5080   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5081   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5082   add_nonneg_nonneg <-- hypreal_le_add_order
  5083 
  5084 * Hyperreal: Separate theorems having to do with type-specific
  5085 versions of constants have been merged into theorems that apply to the
  5086 new polymorphic constants (INCOMPATIBILITY):
  5087 
  5088   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5089   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5090   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5091   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5092   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5093   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5094   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5095   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5096   STAR_diff <-- {STAR,STARC}_diff
  5097   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5098     STARC_hcomplex_of_complex}_image_subset
  5099   starset_n_Un <-- starset{Nat,C}_n_Un
  5100   starset_n_Int <-- starset{Nat,C}_n_Int
  5101   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5102   starset_n_diff <-- starset{Nat,C}_n_diff
  5103   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5104   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5105   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5106   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5107   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5108   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5109   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5110   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5111   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5112   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5113   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5114   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5115   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5116   starfun_diff <-- starfun{C,RC,CR}_diff
  5117   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5118   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5119   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5120   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5121   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5122   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5123   starfun_Id <-- starfunC_Id
  5124   starfun_approx <-- starfun{Nat,CR}_approx
  5125   starfun_capprox <-- starfun{C,RC}_capprox
  5126   starfun_abs <-- starfunNat_rabs
  5127   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5128   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5129   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5130   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5131   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5132   starfun_add_approx <-- starfunCR_add_approx
  5133   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5134   starfun_divide <-- starfun{C,CR,RC}_divide
  5135   starfun_n <-- starfun{Nat,C}_n
  5136   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5137   starfun_n_add <-- starfun{Nat,C}_n_add
  5138   starfun_n_add_minus <-- starfunNat_n_add_minus
  5139   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5140   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5141   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5142 
  5143   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5144   star_n_minus <-- {hypreal,hcomplex}_minus
  5145   star_n_diff <-- {hypreal,hcomplex}_diff
  5146   star_n_mult <-- {hypreal,hcomplex}_mult
  5147   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5148   star_n_le <-- {hypreal,hypnat}_le
  5149   star_n_less <-- {hypreal,hypnat}_less
  5150   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5151   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5152   star_n_abs <-- hypreal_hrabs
  5153   star_n_divide <-- hcomplex_divide
  5154 
  5155   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5156   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5157   star_of_diff <-- hypreal_of_real_diff
  5158   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5159   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5160   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5161   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5162   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5163   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5164   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5165   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5166   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5167   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5168   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5169   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5170   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5171   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5172   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5173   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5174   star_of_power <-- hypreal_of_real_power
  5175   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5176 
  5177 * Hyperreal: new method "transfer" that implements the transfer
  5178 principle of nonstandard analysis. With a subgoal that mentions
  5179 nonstandard types like "'a star", the command "apply transfer"
  5180 replaces it with an equivalent one that mentions only standard types.
  5181 To be successful, all free variables must have standard types; non-
  5182 standard variables must have explicit universal quantifiers.
  5183 
  5184 * Hyperreal: A theory of Taylor series.
  5185 
  5186 
  5187 *** HOLCF ***
  5188 
  5189 * Discontinued special version of 'constdefs' (which used to support
  5190 continuous functions) in favor of the general Pure one with full
  5191 type-inference.
  5192 
  5193 * New simplification procedure for solving continuity conditions; it
  5194 is much faster on terms with many nested lambda abstractions (cubic
  5195 instead of exponential time).
  5196 
  5197 * New syntax for domain package: selector names are now optional.
  5198 Parentheses should be omitted unless argument is lazy, for example:
  5199 
  5200   domain 'a stream = cons "'a" (lazy "'a stream")
  5201 
  5202 * New command 'fixrec' for defining recursive functions with pattern
  5203 matching; defining multiple functions with mutual recursion is also
  5204 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5205 sinr, or any data constructor defined by the domain package. The given
  5206 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5207 syntax and examples.
  5208 
  5209 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5210 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5211 but the proof obligation additionally includes an admissibility
  5212 requirement. The packages generate instances of class cpo or pcpo,
  5213 with continuity and strictness theorems for Rep and Abs.
  5214 
  5215 * HOLCF: Many theorems have been renamed according to a more standard naming
  5216 scheme (INCOMPATIBILITY):
  5217 
  5218   foo_inject:  "foo$x = foo$y ==> x = y"
  5219   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5220   foo_less:    "(foo$x << foo$y) = (x << y)"
  5221   foo_strict:  "foo$UU = UU"
  5222   foo_defined: "... ==> foo$x ~= UU"
  5223   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5224 
  5225 
  5226 *** ZF ***
  5227 
  5228 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5229 including the First Isomorphism Theorem (on quotienting by the kernel
  5230 of a homomorphism).
  5231 
  5232 * ZF/Simplifier: install second copy of type solver that actually
  5233 makes use of TC rules declared to Isar proof contexts (or locales);
  5234 the old version is still required for ML proof scripts.
  5235 
  5236 
  5237 *** Cube ***
  5238 
  5239 * Converted to Isar theory format; use locales instead of axiomatic
  5240 theories.
  5241 
  5242 
  5243 *** ML ***
  5244 
  5245 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5246 for ||>, ||>>, |>>,
  5247 
  5248 * Pure/library.ML no longer defines its own option datatype, but uses
  5249 that of the SML basis, which has constructors NONE and SOME instead of
  5250 None and Some, as well as exception Option.Option instead of OPTION.
  5251 The functions the, if_none, is_some, is_none have been adapted
  5252 accordingly, while Option.map replaces apsome.
  5253 
  5254 * Pure/library.ML: the exception LIST has been given up in favour of
  5255 the standard exceptions Empty and Subscript, as well as
  5256 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5257 superceded by the standard hd and tl functions etc.
  5258 
  5259 A number of basic list functions are no longer exported to the ML
  5260 toplevel, as they are variants of predefined functions.  The following
  5261 suggests how one can translate existing code:
  5262 
  5263     rev_append xs ys = List.revAppend (xs, ys)
  5264     nth_elem (i, xs) = List.nth (xs, i)
  5265     last_elem xs = List.last xs
  5266     flat xss = List.concat xss
  5267     seq fs = List.app fs
  5268     partition P xs = List.partition P xs
  5269     mapfilter f xs = List.mapPartial f xs
  5270 
  5271 * Pure/library.ML: several combinators for linear functional
  5272 transformations, notably reverse application and composition:
  5273 
  5274   x |> f                f #> g
  5275   (x, y) |-> f          f #-> g
  5276 
  5277 * Pure/library.ML: introduced/changed precedence of infix operators:
  5278 
  5279   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5280   infix 2 ?;
  5281   infix 3 o oo ooo oooo;
  5282   infix 4 ~~ upto downto;
  5283 
  5284 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5285 infix operators.
  5286 
  5287 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5288 fold_map support linear functional transformations and nesting.  For
  5289 example:
  5290 
  5291   fold f [x1, ..., xN] y =
  5292     y |> f x1 |> ... |> f xN
  5293 
  5294   (fold o fold) f [xs1, ..., xsN] y =
  5295     y |> fold f xs1 |> ... |> fold f xsN
  5296 
  5297   fold f [x1, ..., xN] =
  5298     f x1 #> ... #> f xN
  5299 
  5300   (fold o fold) f [xs1, ..., xsN] =
  5301     fold f xs1 #> ... #> fold f xsN
  5302 
  5303 * Pure/library.ML: the following selectors on type 'a option are
  5304 available:
  5305 
  5306   the:               'a option -> 'a  (*partial*)
  5307   these:             'a option -> 'a  where 'a = 'b list
  5308   the_default: 'a -> 'a option -> 'a
  5309   the_list:          'a option -> 'a list
  5310 
  5311 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5312 basic operations for association lists, following natural argument
  5313 order; moreover the explicit equality predicate passed here avoids
  5314 potentially expensive polymorphic runtime equality checks.
  5315 The old functions may be expressed as follows:
  5316 
  5317   assoc = uncurry (AList.lookup (op =))
  5318   assocs = these oo AList.lookup (op =)
  5319   overwrite = uncurry (AList.update (op =)) o swap
  5320 
  5321 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5322 
  5323   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5324   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5325 
  5326 replacing make_keylist and keyfilter (occassionally used)
  5327 Naive rewrites:
  5328 
  5329   make_keylist = AList.make
  5330   keyfilter = AList.find (op =)
  5331 
  5332 * eq_fst and eq_snd now take explicit equality parameter, thus
  5333   avoiding eqtypes. Naive rewrites:
  5334 
  5335     eq_fst = eq_fst (op =)
  5336     eq_snd = eq_snd (op =)
  5337 
  5338 * Removed deprecated apl and apr (rarely used).
  5339   Naive rewrites:
  5340 
  5341     apl (n, op) =>>= curry op n
  5342     apr (op, m) =>>= fn n => op (n, m)
  5343 
  5344 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5345 provides a reasonably efficient light-weight implementation of sets as
  5346 lists.
  5347 
  5348 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5349 few new operations; existing lookup and update are now curried to
  5350 follow natural argument order (for use with fold etc.);
  5351 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5352 
  5353 * Pure/General: output via the Isabelle channels of
  5354 writeln/warning/error etc. is now passed through Output.output, with a
  5355 hook for arbitrary transformations depending on the print_mode
  5356 (cf. Output.add_mode -- the first active mode that provides a output
  5357 function wins).  Already formatted output may be embedded into further
  5358 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5359 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5360 accommodate easy composition of diagnostic messages etc.  Programmers
  5361 rarely need to care about Output.output or Output.raw at all, with
  5362 some notable exceptions: Output.output is required when bypassing the
  5363 standard channels (writeln etc.), or in token translations to produce
  5364 properly formatted results; Output.raw is required when capturing
  5365 already output material that will eventually be presented to the user
  5366 a second time.  For the default print mode, both Output.output and
  5367 Output.raw have no effect.
  5368 
  5369 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5370 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5371 cumulative results are displayed at the end of a batch session.
  5372 
  5373 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5374 replaced by File.platform_path and File.shell_path (with appropriate
  5375 hooks).  This provides a clean interface for unusual systems where the
  5376 internal and external process view of file names are different.
  5377 
  5378 * Pure: more efficient orders for basic syntactic entities: added
  5379 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5380 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5381 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5382 orders now -- potential INCOMPATIBILITY for code that depends on a
  5383 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5384 Library.sort_strings on result).
  5385 
  5386 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5387 fold_types traverse types/terms from left to right, observing natural
  5388 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5389 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5390 
  5391 * Pure: name spaces have been refined, with significant changes of the
  5392 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5393 to extern(_table).  The plain name entry path is superceded by a
  5394 general 'naming' context, which also includes the 'policy' to produce
  5395 a fully qualified name and external accesses of a fully qualified
  5396 name; NameSpace.extend is superceded by context dependent
  5397 Sign.declare_name.  Several theory and proof context operations modify
  5398 the naming context.  Especially note Theory.restore_naming and
  5399 ProofContext.restore_naming to get back to a sane state; note that
  5400 Theory.add_path is no longer sufficient to recover from
  5401 Theory.absolute_path in particular.
  5402 
  5403 * Pure: new flags short_names (default false) and unique_names
  5404 (default true) for controlling output of qualified names.  If
  5405 short_names is set, names are printed unqualified.  If unique_names is
  5406 reset, the name prefix is reduced to the minimum required to achieve
  5407 the original result when interning again, even if there is an overlap
  5408 with earlier declarations.
  5409 
  5410 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5411 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5412 (useful for printing error messages).  INCOMPATIBILITY.
  5413 
  5414 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5415 Theory.theory are now identified, referring to the universal
  5416 Context.theory (see Pure/context.ML).  Actual signature and theory
  5417 content is managed as theory data.  The old code and interfaces were
  5418 spread over many files and structures; the new arrangement introduces
  5419 considerable INCOMPATIBILITY to gain more clarity:
  5420 
  5421   Context -- theory management operations (name, identity, inclusion,
  5422     parents, ancestors, merge, etc.), plus generic theory data;
  5423 
  5424   Sign -- logical signature and syntax operations (declaring consts,
  5425     types, etc.), plus certify/read for common entities;
  5426 
  5427   Theory -- logical theory operations (stating axioms, definitions,
  5428     oracles), plus a copy of logical signature operations (consts,
  5429     types, etc.); also a few basic management operations (Theory.copy,
  5430     Theory.merge, etc.)
  5431 
  5432 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5433 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5434 for convenience -- they merely return the theory.
  5435 
  5436 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5437 
  5438 * Pure: the Isar proof context type is already defined early in Pure
  5439 as Context.proof (note that ProofContext.context and Proof.context are
  5440 aliases, where the latter is the preferred name).  This enables other
  5441 Isabelle components to refer to that type even before Isar is present.
  5442 
  5443 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5444 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5445 any of these kinds.  For example, Sign.intern typeK is now
  5446 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5447 Theory.hide_types.  Also note that former
  5448 Theory.hide_classes/types/consts are now
  5449 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5450 internalize their arguments!  INCOMPATIBILITY.
  5451 
  5452 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5453 datatype thmref (with constructors Name and NameSelection) instead of
  5454 plain string -- INCOMPATIBILITY;
  5455 
  5456 * Pure: cases produced by proof methods specify options, where NONE
  5457 means to remove case bindings -- INCOMPATIBILITY in
  5458 (RAW_)METHOD_CASES.
  5459 
  5460 * Pure: the following operations retrieve axioms or theorems from a
  5461 theory node or theory hierarchy, respectively:
  5462 
  5463   Theory.axioms_of: theory -> (string * term) list
  5464   Theory.all_axioms_of: theory -> (string * term) list
  5465   PureThy.thms_of: theory -> (string * thm) list
  5466   PureThy.all_thms_of: theory -> (string * thm) list
  5467 
  5468 * Pure: print_tac now outputs the goal through the trace channel.
  5469 
  5470 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5471 Reference Toplevel.debug (default false) controls detailed printing
  5472 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5473 controls execution profiling -- set to 1 for time and 2 for space
  5474 (both increase the runtime).
  5475 
  5476 * Isar session: The initial use of ROOT.ML is now always timed,
  5477 i.e. the log will show the actual process times, in contrast to the
  5478 elapsed wall-clock time that the outer shell wrapper produces.
  5479 
  5480 * Simplifier: improved handling of bound variables (nameless
  5481 representation, avoid allocating new strings).  Simprocs that invoke
  5482 the Simplifier recursively should use Simplifier.inherit_bounds to
  5483 avoid local name clashes.  Failure to do so produces warnings
  5484 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5485 for further details.
  5486 
  5487 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5488 bindings for all theorems stored within a given theory; this may help
  5489 in porting non-Isar theories to Isar ones, while keeping ML proof
  5490 scripts for the time being.
  5491 
  5492 * ML operator HTML.with_charset specifies the charset begin used for
  5493 generated HTML files.  For example:
  5494 
  5495   HTML.with_charset "utf-8" use_thy "Hebrew";
  5496   HTML.with_charset "utf-8" use_thy "Chinese";
  5497 
  5498 
  5499 *** System ***
  5500 
  5501 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5502 isabelle, isatool etc.).
  5503 
  5504 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5505 isatool doc, isatool mkdir, display_drafts etc.).
  5506 
  5507 * isatool usedir: option -f allows specification of the ML file to be
  5508 used by Isabelle; default is ROOT.ML.
  5509 
  5510 * New isatool version outputs the version identifier of the Isabelle
  5511 distribution being used.
  5512 
  5513 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5514 (containing Boolean satisfiability problems) into Isabelle/HOL
  5515 theories.
  5516 
  5517 
  5518 
  5519 New in Isabelle2004 (April 2004)
  5520 --------------------------------
  5521 
  5522 *** General ***
  5523 
  5524 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5525   Replaces linorder.ML.
  5526 
  5527 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5528   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5529   (\<a>...\<z>), are now considered normal letters, and can therefore
  5530   be used anywhere where an ASCII letter (a...zA...Z) has until
  5531   now. COMPATIBILITY: This obviously changes the parsing of some
  5532   terms, especially where a symbol has been used as a binder, say
  5533   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5534   as an identifier.  Fix it by inserting a space around former
  5535   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5536   existing theory and ML files.
  5537 
  5538 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5539 
  5540 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5541   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5542   a normal (but invisible) letter. For multiple letter subscripts repeat
  5543   \<^isub> like this: x\<^isub>1\<^isub>2.
  5544 
  5545 * Pure: There are now sub-/superscripts that can span more than one
  5546   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5547   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5548   superscript. The new control characters are not identifier parts.
  5549 
  5550 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5551   content of "..." to the latex file instead of \isacntrl... . The "..."
  5552   may consist of any printable characters excluding the end bracket >.
  5553 
  5554 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5555   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5556   declare constants "final", which prevents their being given a definition
  5557   later.  It is useful for constants whose behaviour is fixed axiomatically
  5558   rather than definitionally, such as the meta-logic connectives.
  5559 
  5560 * Pure: 'instance' now handles general arities with general sorts
  5561   (i.e. intersections of classes),
  5562 
  5563 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5564   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5565   It can be changed to alter the colors/layout of generated pages.
  5566 
  5567 
  5568 *** Isar ***
  5569 
  5570 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5571   cut_tac, subgoal_tac and thin_tac:
  5572   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5573     locales are no longer forced to write Isar proof scripts.
  5574     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5575     emulations.
  5576   - INCOMPATIBILITY: names of variables to be instantiated may no
  5577     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5578     This is consistent with the instantiation attribute "where".
  5579 
  5580 * Attributes "where" and "of":
  5581   - Now take type variables of instantiated theorem into account when reading
  5582     the instantiation string.  This fixes a bug that caused instantiated
  5583     theorems to have too special types in some circumstances.
  5584   - "where" permits explicit instantiations of type variables.
  5585 
  5586 * Calculation commands "moreover" and "also" no longer interfere with
  5587   current facts ("this"), admitting arbitrary combinations with "then"
  5588   and derived forms.
  5589 
  5590 * Locales:
  5591   - Goal statements involving the context element "includes" no longer
  5592     generate theorems with internal delta predicates (those ending on
  5593     "_axioms") in the premise.
  5594     Resolve particular premise with <locale>.intro to obtain old form.
  5595   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5596     specification and "includes" elements in goal statement.
  5597   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5598     [intro?] and [elim?] (respectively) by default.
  5599   - Experimental command for instantiation of locales in proof contexts:
  5600         instantiate <label>[<attrs>]: <loc>
  5601     Instantiates locale <loc> and adds all its theorems to the current context
  5602     taking into account their attributes.  Label and attrs are optional
  5603     modifiers, like in theorem declarations.  If present, names of
  5604     instantiated theorems are qualified with <label>, and the attributes
  5605     <attrs> are applied after any attributes these theorems might have already.
  5606       If the locale has assumptions, a chained fact of the form
  5607     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5608     are derived.  The command does not support old-style locales declared
  5609     with "locale (open)".
  5610       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5611 
  5612 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5613   (Isar) contexts.
  5614 
  5615 
  5616 *** HOL ***
  5617 
  5618 * Proof import: new image HOL4 contains the imported library from
  5619   the HOL4 system with about 2500 theorems. It is imported by
  5620   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5621   can be used like any other Isabelle image.  See
  5622   HOL/Import/HOL/README for more information.
  5623 
  5624 * Simplifier:
  5625   - Much improved handling of linear and partial orders.
  5626     Reasoners for linear and partial orders are set up for type classes
  5627     "linorder" and "order" respectively, and are added to the default simpset
  5628     as solvers.  This means that the simplifier can build transitivity chains
  5629     to solve goals from the assumptions.
  5630   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5631     of blast or auto after simplification become unnecessary because the goal
  5632     is solved by simplification already.
  5633 
  5634 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5635     all proved in axiomatic type classes for semirings, rings and fields.
  5636 
  5637 * Numerics:
  5638   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5639     now formalized using the Ring_and_Field theory mentioned above.
  5640   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5641     than before, because now they are set up once in a generic manner.
  5642   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5643     Look for the general versions in Ring_and_Field (and Power if they concern
  5644     exponentiation).
  5645 
  5646 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5647 
  5648 * Records:
  5649   - Record types are now by default printed with their type abbreviation
  5650     instead of the list of all field types. This can be configured via
  5651     the reference "print_record_type_abbr".
  5652   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5653     (not enabled by default).
  5654   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5655     EX x. x = sel r to True (not enabled by default).
  5656   - Tactic "record_split_simp_tac" to split and simplify records added.
  5657 
  5658 * 'specification' command added, allowing for definition by
  5659   specification.  There is also an 'ax_specification' command that
  5660   introduces the new constants axiomatically.
  5661 
  5662 * arith(_tac) is now able to generate counterexamples for reals as well.
  5663 
  5664 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5665 
  5666 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5667   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5668 
  5669 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5670   matrix theory to linear programming.
  5671 
  5672 * Unions and Intersections:
  5673   The latex output syntax of UN and INT has been changed
  5674   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5675   i.e. the index formulae has become a subscript.
  5676   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5677 
  5678 * Unions and Intersections over Intervals:
  5679   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5680   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5681   like in normal math, and corresponding versions for < and for intersection.
  5682 
  5683 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5684   lexicographic dictonary ordering has been added as "lexord".
  5685 
  5686 * ML: the legacy theory structures Int and List have been removed. They had
  5687   conflicted with ML Basis Library structures having the same names.
  5688 
  5689 * 'refute' command added to search for (finite) countermodels.  Only works
  5690   for a fragment of HOL.  The installation of an external SAT solver is
  5691   highly recommended.  See "HOL/Refute.thy" for details.
  5692 
  5693 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5694   formulae under an assignment of free variables to random values.
  5695   In contrast to 'refute', it can deal with inductive datatypes,
  5696   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5697   for examples.
  5698 
  5699 
  5700 *** HOLCF ***
  5701 
  5702 * Streams now come with concatenation and are part of the HOLCF image
  5703 
  5704 
  5705 
  5706 New in Isabelle2003 (May 2003)
  5707 ------------------------------
  5708 
  5709 *** General ***
  5710 
  5711 * Provers/simplifier:
  5712 
  5713   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5714     Assumptions are now subject to complete mutual simplification,
  5715     not just from left to right. The simplifier now preserves
  5716     the order of assumptions.
  5717 
  5718     Potential INCOMPATIBILITY:
  5719 
  5720     -- simp sometimes diverges where the old version did
  5721        not, e.g. invoking simp on the goal
  5722 
  5723         [| P (f x); y = x; f x = f y |] ==> Q
  5724 
  5725        now gives rise to the infinite reduction sequence
  5726 
  5727         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5728 
  5729        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5730        kind of problem.
  5731 
  5732     -- Tactics combining classical reasoner and simplification (such as auto)
  5733        are also affected by this change, because many of them rely on
  5734        simp. They may sometimes diverge as well or yield a different numbers
  5735        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5736        in case of problems. Sometimes subsequent calls to the classical
  5737        reasoner will fail because a preceeding call to the simplifier too
  5738        eagerly simplified the goal, e.g. deleted redundant premises.
  5739 
  5740   - The simplifier trace now shows the names of the applied rewrite rules
  5741 
  5742   - You can limit the number of recursive invocations of the simplifier
  5743     during conditional rewriting (where the simplifie tries to solve the
  5744     conditions before applying the rewrite rule):
  5745     ML "simp_depth_limit := n"
  5746     where n is an integer. Thus you can force termination where previously
  5747     the simplifier would diverge.
  5748 
  5749   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5750 
  5751   - No longer aborts on failed congruence proof.  Instead, the
  5752     congruence is ignored.
  5753 
  5754 * Pure: New generic framework for extracting programs from constructive
  5755   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5756   as HOL/Extraction for some case studies.
  5757 
  5758 * Pure: The main goal of the proof state is no longer shown by default, only
  5759 the subgoals. This behaviour is controlled by a new flag.
  5760    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5761 (ML: Proof.show_main_goal).
  5762 
  5763 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5764 rules whose conclusion matches subgoal 1:
  5765       PG menu: Isabelle/Isar -> Show me -> matching rules
  5766 The rules are ordered by how closely they match the subgoal.
  5767 In particular, rules that solve a subgoal outright are displayed first
  5768 (or rather last, the way they are printed).
  5769 (ML: ProofGeneral.print_intros())
  5770 
  5771 * Pure: New flag trace_unify_fail causes unification to print
  5772 diagnostic information (PG: in trace buffer) when it fails. This is
  5773 useful for figuring out why single step proofs like rule, erule or
  5774 assumption failed.
  5775 
  5776 * Pure: Locale specifications now produce predicate definitions
  5777 according to the body of text (covering assumptions modulo local
  5778 definitions); predicate "loc_axioms" covers newly introduced text,
  5779 while "loc" is cumulative wrt. all included locale expressions; the
  5780 latter view is presented only on export into the global theory
  5781 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5782 on the old view without predicates;
  5783 
  5784 * Pure: predefined locales "var" and "struct" are useful for sharing
  5785 parameters (as in CASL, for example); just specify something like
  5786 ``var x + var y + struct M'' as import;
  5787 
  5788 * Pure: improved thms_containing: proper indexing of facts instead of
  5789 raw theorems; check validity of results wrt. current name space;
  5790 include local facts of proof configuration (also covers active
  5791 locales), cover fixed variables in index; may use "_" in term
  5792 specification; an optional limit for the number of printed facts may
  5793 be given (the default is 40);
  5794 
  5795 * Pure: disallow duplicate fact bindings within new-style theory files
  5796 (batch-mode only);
  5797 
  5798 * Provers: improved induct method: assumptions introduced by case
  5799 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5800 the goal statement); "foo" still refers to all facts collectively;
  5801 
  5802 * Provers: the function blast.overloaded has been removed: all constants
  5803 are regarded as potentially overloaded, which improves robustness in exchange
  5804 for slight decrease in efficiency;
  5805 
  5806 * Provers/linorder: New generic prover for transitivity reasoning over
  5807 linear orders.  Note: this prover is not efficient!
  5808 
  5809 * Isar: preview of problems to finish 'show' now produce an error
  5810 rather than just a warning (in interactive mode);
  5811 
  5812 
  5813 *** HOL ***
  5814 
  5815 * arith(_tac)
  5816 
  5817  - Produces a counter example if it cannot prove a goal.
  5818    Note that the counter example may be spurious if the goal is not a formula
  5819    of quantifier-free linear arithmetic.
  5820    In ProofGeneral the counter example appears in the trace buffer.
  5821 
  5822  - Knows about div k and mod k where k is a numeral of type nat or int.
  5823 
  5824  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5825    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5826    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5827 
  5828 * simp's arithmetic capabilities have been enhanced a bit: it now
  5829 takes ~= in premises into account (by performing a case split);
  5830 
  5831 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5832 are distributed over a sum of terms;
  5833 
  5834 * New tactic "trans_tac" and method "trans" instantiate
  5835 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5836 "<=", "<" and "=").
  5837 
  5838 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5839 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5840 
  5841 * 'typedef' command has new option "open" to suppress the set
  5842 definition;
  5843 
  5844 * functions Min and Max on finite sets have been introduced (theory
  5845 Finite_Set);
  5846 
  5847 * attribute [symmetric] now works for relations as well; it turns
  5848 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5849 
  5850 * induct over a !!-quantified statement (say !!x1..xn):
  5851   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5852 
  5853 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5854 %x. None. Warning: empty_def now refers to the previously hidden definition
  5855 of the empty set.
  5856 
  5857 * Algebra: formalization of classical algebra.  Intended as base for
  5858 any algebraic development in Isabelle.  Currently covers group theory
  5859 (up to Sylow's theorem) and ring theory (Universal Property of
  5860 Univariate Polynomials).  Contributions welcome;
  5861 
  5862 * GroupTheory: deleted, since its material has been moved to Algebra;
  5863 
  5864 * Complex: new directory of the complex numbers with numeric constants,
  5865 nonstandard complex numbers, and some complex analysis, standard and
  5866 nonstandard (Jacques Fleuriot);
  5867 
  5868 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5869 
  5870 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5871 Fleuriot);
  5872 
  5873 * Real/HahnBanach: updated and adapted to locales;
  5874 
  5875 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5876 Gray and Kramer);
  5877 
  5878 * UNITY: added the Meier-Sanders theory of progress sets;
  5879 
  5880 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5881 as abstract algorithms, instantiated to the JVM;
  5882 
  5883 * Bali: Java source language formalization. Type system, operational
  5884 semantics, axiomatic semantics. Supported language features:
  5885 classes, interfaces, objects,virtual methods, static methods,
  5886 static/instance fields, arrays, access modifiers, definite
  5887 assignment, exceptions.
  5888 
  5889 
  5890 *** ZF ***
  5891 
  5892 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5893 universe, etc.);
  5894 
  5895 * Main ZF: virtually all theories converted to new-style format;
  5896 
  5897 
  5898 *** ML ***
  5899 
  5900 * Pure: Tactic.prove provides sane interface for internal proofs;
  5901 omits the infamous "standard" operation, so this is more appropriate
  5902 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5903 
  5904 * Pure: improved error reporting of simprocs;
  5905 
  5906 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5907 up simprocs;
  5908 
  5909 
  5910 *** Document preparation ***
  5911 
  5912 * uses \par instead of \\ for line breaks in theory text. This may
  5913 shift some page breaks in large documents. To get the old behaviour
  5914 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5915 
  5916 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5917 other packages
  5918 
  5919 * \<euro> now needs package babel/greek instead of marvosym (which
  5920 broke \Rightarrow)
  5921 
  5922 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5923 textcomp package)
  5924 
  5925 
  5926 
  5927 New in Isabelle2002 (March 2002)
  5928 --------------------------------
  5929 
  5930 *** Document preparation ***
  5931 
  5932 * greatly simplified document preparation setup, including more
  5933 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5934 instructive isatool mkdir; users should basically be able to get
  5935 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5936 users may run a separate document processing stage manually like this:
  5937 "isatool usedir -D output HOL Test && isatool document Test/output";
  5938 
  5939 * theory dependency graph may now be incorporated into documents;
  5940 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5941 with \includegraphics of LaTeX;
  5942 
  5943 * proper spacing of consecutive markup elements, especially text
  5944 blocks after section headings;
  5945 
  5946 * support bold style (for single symbols only), input syntax is like
  5947 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5948 
  5949 * \<bullet> is now output as bold \cdot by default, which looks much
  5950 better in printed text;
  5951 
  5952 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5953 note that these symbols are currently unavailable in Proof General /
  5954 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5955 
  5956 * isatool latex no longer depends on changed TEXINPUTS, instead
  5957 isatool document copies the Isabelle style files to the target
  5958 location;
  5959 
  5960 
  5961 *** Isar ***
  5962 
  5963 * Pure/Provers: improved proof by cases and induction;
  5964   - 'case' command admits impromptu naming of parameters (such as
  5965     "case (Suc n)");
  5966   - 'induct' method divinates rule instantiation from the inductive
  5967     claim; no longer requires excessive ?P bindings for proper
  5968     instantiation of cases;
  5969   - 'induct' method properly enumerates all possibilities of set/type
  5970     rules; as a consequence facts may be also passed through *type*
  5971     rules without further ado;
  5972   - 'induct' method now derives symbolic cases from the *rulified*
  5973     rule (before it used to rulify cases stemming from the internal
  5974     atomized version); this means that the context of a non-atomic
  5975     statement becomes is included in the hypothesis, avoiding the
  5976     slightly cumbersome show "PROP ?case" form;
  5977   - 'induct' may now use elim-style induction rules without chaining
  5978     facts, using ``missing'' premises from the goal state; this allows
  5979     rules stemming from inductive sets to be applied in unstructured
  5980     scripts, while still benefitting from proper handling of non-atomic
  5981     statements; NB: major inductive premises need to be put first, all
  5982     the rest of the goal is passed through the induction;
  5983   - 'induct' proper support for mutual induction involving non-atomic
  5984     rule statements (uses the new concept of simultaneous goals, see
  5985     below);
  5986   - append all possible rule selections, but only use the first
  5987     success (no backtracking);
  5988   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5989   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5990   - added 'print_induct_rules' (covered by help item in recent Proof
  5991     General versions);
  5992   - moved induct/cases attributes to Pure, methods to Provers;
  5993   - generic method setup instantiated for FOL and HOL;
  5994 
  5995 * Pure: support multiple simultaneous goal statements, for example
  5996 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5997 meta-level mechanism, this acts as if several individual goals had
  5998 been stated separately; in particular common proof methods need to be
  5999 repeated in order to cover all claims; note that a single elimination
  6000 step is *not* sufficient to establish the two conjunctions, so this
  6001 fails:
  6002 
  6003   assume "A & B" then have A and B ..   (*".." fails*)
  6004 
  6005 better use "obtain" in situations as above; alternative refer to
  6006 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6007 
  6008 * Pure: proper integration with ``locales''; unlike the original
  6009 version by Florian Kammller, Isar locales package high-level proof
  6010 contexts rather than raw logical ones (e.g. we admit to include
  6011 attributes everywhere); operations on locales include merge and
  6012 rename; support for implicit arguments (``structures''); simultaneous
  6013 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6014 some examples;
  6015 
  6016 * Pure: the following commands have been ``localized'', supporting a
  6017 target locale specification "(in name)": 'lemma', 'theorem',
  6018 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6019 stored both within the locale and at the theory level (exported and
  6020 qualified by the locale name);
  6021 
  6022 * Pure: theory goals may now be specified in ``long'' form, with
  6023 ad-hoc contexts consisting of arbitrary locale elements. for example
  6024 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6025 definitions may be given, too); the result is a meta-level rule with
  6026 the context elements being discharged in the obvious way;
  6027 
  6028 * Pure: new proof command 'using' allows to augment currently used
  6029 facts after a goal statement ('using' is syntactically analogous to
  6030 'apply', but acts on the goal's facts only); this allows chained facts
  6031 to be separated into parts given before and after a claim, as in
  6032 ``from a and b have C using d and e <proof>'';
  6033 
  6034 * Pure: renamed "antecedent" case to "rule_context";
  6035 
  6036 * Pure: new 'judgment' command records explicit information about the
  6037 object-logic embedding (used by several tools internally); no longer
  6038 use hard-wired "Trueprop";
  6039 
  6040 * Pure: added 'corollary' command;
  6041 
  6042 * Pure: fixed 'token_translation' command;
  6043 
  6044 * Pure: removed obsolete 'exported' attribute;
  6045 
  6046 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6047 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6048 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6049 
  6050 * Pure: method 'atomize' presents local goal premises as object-level
  6051 statements (atomic meta-level propositions); setup controlled via
  6052 rewrite rules declarations of 'atomize' attribute; example
  6053 application: 'induct' method with proper rule statements in improper
  6054 proof *scripts*;
  6055 
  6056 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6057 now consider the syntactic context of assumptions, giving a better
  6058 chance to get type-inference of the arguments right (this is
  6059 especially important for locales);
  6060 
  6061 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6062 mode;
  6063 
  6064 * Pure/obtain: the formal conclusion "thesis", being marked as
  6065 ``internal'', may no longer be reference directly in the text;
  6066 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6067 situations;
  6068 
  6069 * Pure: generic 'sym' attribute which declares a rule both as pure
  6070 'elim?' and for the 'symmetric' operation;
  6071 
  6072 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6073 text; the fixed correlation with particular command syntax has been
  6074 discontinued;
  6075 
  6076 * Pure: new method 'rules' is particularly well-suited for proof
  6077 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6078 but often produces more compact proof terms with less detours;
  6079 
  6080 * Pure/Provers/classical: simplified integration with pure rule
  6081 attributes and methods; the classical "intro?/elim?/dest?"
  6082 declarations coincide with the pure ones; the "rule" method no longer
  6083 includes classically swapped intros; "intro" and "elim" methods no
  6084 longer pick rules from the context; also got rid of ML declarations
  6085 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6086 INCOMPATIBILITY;
  6087 
  6088 * Provers/classical: attribute 'swapped' produces classical inversions
  6089 of introduction rules;
  6090 
  6091 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6092 rules instead of full simplifier context; 'iff' attribute handles
  6093 conditional rules;
  6094 
  6095 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6096 
  6097 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6098 "(permissive)" option to recover old behavior;
  6099 
  6100 * HOL: 'inductive' no longer features separate (collective) attributes
  6101 for 'intros' (was found too confusing);
  6102 
  6103 * HOL: properly declared induction rules less_induct and
  6104 wf_induct_rule;
  6105 
  6106 
  6107 *** HOL ***
  6108 
  6109 * HOL: moved over to sane numeral syntax; the new policy is as
  6110 follows:
  6111 
  6112   - 0 and 1 are polymorphic constants, which are defined on any
  6113   numeric type (nat, int, real etc.);
  6114 
  6115   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6116   binary representation internally;
  6117 
  6118   - type nat has special constructor Suc, and generally prefers Suc 0
  6119   over 1::nat and Suc (Suc 0) over 2::nat;
  6120 
  6121 This change may cause significant problems of INCOMPATIBILITY; here
  6122 are some hints on converting existing sources:
  6123 
  6124   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6125   entities, so expressions involving "-" (unary or binary minus) need
  6126   to be spaced properly;
  6127 
  6128   - existing occurrences of "1" may need to be constraint "1::nat" or
  6129   even replaced by Suc 0; similar for old "2";
  6130 
  6131   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6132 
  6133   - remove all special provisions on numerals in proofs;
  6134 
  6135 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6136 representation (depends on bin_arith_simps in the default context);
  6137 
  6138 * HOL: symbolic syntax for x^2 (numeral 2);
  6139 
  6140 * HOL: the class of all HOL types is now called "type" rather than
  6141 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6142 in axclass/classes, instance/arities, and (usually rare) occurrences
  6143 in typings (of consts etc.); internally the class is called
  6144 "HOL.type", ML programs should refer to HOLogic.typeS;
  6145 
  6146 * HOL/record package improvements:
  6147   - new derived operations "fields" to build a partial record section,
  6148     "extend" to promote a fixed record to a record scheme, and
  6149     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6150     declared as simp by default;
  6151   - shared operations ("more", "fields", etc.) now need to be always
  6152     qualified) --- potential INCOMPATIBILITY;
  6153   - removed "make_scheme" operations (use "make" with "extend") --
  6154     INCOMPATIBILITY;
  6155   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6156   - provides cases/induct rules for use with corresponding Isar
  6157     methods (for concrete records, record schemes, concrete more
  6158     parts, and schematic more parts -- in that order);
  6159   - internal definitions directly based on a light-weight abstract
  6160     theory of product types over typedef rather than datatype;
  6161 
  6162 * HOL: generic code generator for generating executable ML code from
  6163 specifications; specific support for HOL constructs such as inductive
  6164 datatypes and sets, as well as recursive functions; can be invoked
  6165 via 'generate_code' theory section;
  6166 
  6167 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6168 
  6169 * HOL: consolidated and renamed several theories.  In particular:
  6170         Ord.thy has been absorbed into HOL.thy
  6171         String.thy has been absorbed into List.thy
  6172 
  6173 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6174 (beware of argument permutation!);
  6175 
  6176 * HOL: linorder_less_split superseded by linorder_cases;
  6177 
  6178 * HOL/List: "nodups" renamed to "distinct";
  6179 
  6180 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6181 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6182   - Ex_def has changed, now need to use some_eq_ex
  6183 
  6184 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6185 in this (rare) case use:
  6186 
  6187   delSWrapper "split_all_tac"
  6188   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6189 
  6190 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6191 MAY FAIL;
  6192 
  6193 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6194 Isabelle's type classes, ^ on functions and relations has too general
  6195 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6196 necessary to attach explicit type constraints;
  6197 
  6198 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6199 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6200 renamed accordingly (eg "compI" -> "rel_compI").
  6201 
  6202 * HOL: syntax translations now work properly with numerals and records
  6203 expressions;
  6204 
  6205 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6206 of "lam" -- INCOMPATIBILITY;
  6207 
  6208 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6209 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6210 renamed "Product_Type.unit";
  6211 
  6212 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6213 
  6214 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6215 the "cases" method);
  6216 
  6217 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6218 Florian Kammller);
  6219 
  6220 * HOL/IMP: updated and converted to new-style theory format; several
  6221 parts turned into readable document, with proper Isar proof texts and
  6222 some explanations (by Gerwin Klein);
  6223 
  6224 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6225 
  6226 * HOL-Hyperreal is now a logic image;
  6227 
  6228 
  6229 *** HOLCF ***
  6230 
  6231 * Isar: consts/constdefs supports mixfix syntax for continuous
  6232 operations;
  6233 
  6234 * Isar: domain package adapted to new-style theory format, e.g. see
  6235 HOLCF/ex/Dnat.thy;
  6236 
  6237 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6238 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6239 lift.induct_tac, always use UU instead of Undef;
  6240 
  6241 * HOLCF/IMP: updated and converted to new-style theory;
  6242 
  6243 
  6244 *** ZF ***
  6245 
  6246 * Isar: proper integration of logic-specific tools and packages,
  6247 including theory commands '(co)inductive', '(co)datatype',
  6248 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6249 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6250 
  6251 * theory Main no longer includes AC; for the Axiom of Choice, base
  6252 your theory on Main_ZFC;
  6253 
  6254 * the integer library now covers quotients and remainders, with many
  6255 laws relating division to addition, multiplication, etc.;
  6256 
  6257 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6258 typeless version of the formalism;
  6259 
  6260 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6261 format;
  6262 
  6263 * ZF/Induct: new directory for examples of inductive definitions,
  6264 including theory Multiset for multiset orderings; converted to
  6265 new-style theory format;
  6266 
  6267 * ZF: many new theorems about lists, ordinals, etc.;
  6268 
  6269 
  6270 *** General ***
  6271 
  6272 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6273 variable proof controls level of detail: 0 = no proofs (only oracle
  6274 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6275 also ref manual for further ML interfaces;
  6276 
  6277 * Pure/axclass: removed obsolete ML interface
  6278 goal_subclass/goal_arity;
  6279 
  6280 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6281 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6282 separate tokens, so expressions involving minus need to be spaced
  6283 properly;
  6284 
  6285 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6286 rather than "infixl" or "infixr";
  6287 
  6288 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6289 sort constraint specifications in type inference; e.g. "x::_::foo"
  6290 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6291 type variable);
  6292 
  6293 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6294 control output of nested => (types); the default behavior is
  6295 "type_brackets";
  6296 
  6297 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6298 tokens into AST constants;
  6299 
  6300 * Pure/syntax: prefer later declarations of translations and print
  6301 translation functions; potential INCOMPATIBILITY: need to reverse
  6302 multiple declarations for same syntax element constant;
  6303 
  6304 * Pure/show_hyps reset by default (in accordance to existing Isar
  6305 practice);
  6306 
  6307 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6308 addSafter;
  6309 
  6310 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6311 as well;
  6312 
  6313 * system: tested support for MacOS X; should be able to get Isabelle +
  6314 Proof General to work in a plain Terminal after installing Poly/ML
  6315 (e.g. from the Isabelle distribution area) and GNU bash alone
  6316 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6317 support requires further installations, e.g. from
  6318 http://fink.sourceforge.net/);
  6319 
  6320 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6321 
  6322 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6323 of 40 MB), cf. ML_OPTIONS;
  6324 
  6325 * system: Proof General keywords specification is now part of the
  6326 Isabelle distribution (see etc/isar-keywords.el);
  6327 
  6328 * system: support for persistent Proof General sessions (refrain from
  6329 outdating all loaded theories on startup); user may create writable
  6330 logic images like this: ``isabelle -q HOL Test'';
  6331 
  6332 * system: smart selection of Isabelle process versus Isabelle
  6333 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6334 run both "isabelle" and "Isabelle" even if file names are badly
  6335 damaged (executable inspects the case of the first letter of its own
  6336 name); added separate "isabelle-process" and "isabelle-interface";
  6337 
  6338 * system: refrain from any attempt at filtering input streams; no
  6339 longer support ``8bit'' encoding of old isabelle font, instead proper
  6340 iso-latin characters may now be used; the related isatools
  6341 "symbolinput" and "nonascii" have disappeared as well;
  6342 
  6343 * system: removed old "xterm" interface (the print modes "xterm" and
  6344 "xterm_color" are still available for direct use in a suitable
  6345 terminal);
  6346 
  6347 
  6348 
  6349 New in Isabelle99-2 (February 2001)
  6350 -----------------------------------
  6351 
  6352 *** Overview of INCOMPATIBILITIES ***
  6353 
  6354 * HOL: please note that theories in the Library and elsewhere often use the
  6355 new-style (Isar) format; to refer to their theorems in an ML script you must
  6356 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6357 
  6358 * HOL: inductive package no longer splits induction rule aggressively,
  6359 but only as far as specified by the introductions given; the old
  6360 format may be recovered via ML function complete_split_rule or attribute
  6361 'split_rule (complete)';
  6362 
  6363 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6364 gfp_Tarski to gfp_unfold;
  6365 
  6366 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6367 
  6368 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6369 relation); infix "^^" has been renamed "``"; infix "``" has been
  6370 renamed "`"; "univalent" has been renamed "single_valued";
  6371 
  6372 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6373 operation;
  6374 
  6375 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6376 
  6377 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6378 
  6379 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6380 consequence, it is no longer monotonic wrt. the local goal context
  6381 (which is now passed through the inductive cases);
  6382 
  6383 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6384 \<gg> to \<ggreater>;
  6385 
  6386 
  6387 *** Document preparation ***
  6388 
  6389 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6390 available: are "it" for near math-mode best-style output, "sl" for
  6391 slanted text style, and "tt" for plain type-writer; if no
  6392 \isabellestyle command is given, output is according to slanted
  6393 type-writer);
  6394 
  6395 * support sub/super scripts (for single symbols only), input syntax is
  6396 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6397 
  6398 * some more standard symbols; see Appendix A of the system manual for
  6399 the complete list of symbols defined in isabellesym.sty;
  6400 
  6401 * improved isabelle style files; more abstract symbol implementation
  6402 (should now use \isamath{...} and \isatext{...} in custom symbol
  6403 definitions);
  6404 
  6405 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6406 state; Note that presentation of goal states does not conform to
  6407 actual human-readable proof documents.  Please do not include goal
  6408 states into document output unless you really know what you are doing!
  6409 
  6410 * proper indentation of antiquoted output with proportional LaTeX
  6411 fonts;
  6412 
  6413 * no_document ML operator temporarily disables LaTeX document
  6414 generation;
  6415 
  6416 * isatool unsymbolize tunes sources for plain ASCII communication;
  6417 
  6418 
  6419 *** Isar ***
  6420 
  6421 * Pure: Isar now suffers initial goal statements to contain unbound
  6422 schematic variables (this does not conform to actual readable proof
  6423 documents, due to unpredictable outcome and non-compositional proof
  6424 checking); users who know what they are doing may use schematic goals
  6425 for Prolog-style synthesis of proven results;
  6426 
  6427 * Pure: assumption method (an implicit finishing) now handles actual
  6428 rules as well;
  6429 
  6430 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6431 initial goal, declare "that" only as Pure intro (only for single
  6432 steps); the "that" rule assumption may now be involved in implicit
  6433 finishing, thus ".." becomes a feasible for trivial obtains;
  6434 
  6435 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6436 instance proofs may be performed by "..";
  6437 
  6438 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6439 statements as well;
  6440 
  6441 * Pure: more robust selection of calculational rules;
  6442 
  6443 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6444 rule (as well as the assumption rule);
  6445 
  6446 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6447 lemmas, using the graph browser tool;
  6448 
  6449 * Pure: predict failure of "show" in interactive mode;
  6450 
  6451 * Pure: 'thms_containing' now takes actual terms as arguments;
  6452 
  6453 * HOL: improved method 'induct' --- now handles non-atomic goals
  6454 (potential INCOMPATIBILITY); tuned error handling;
  6455 
  6456 * HOL: cases and induct rules now provide explicit hints about the
  6457 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6458 any remaining facts are inserted into the goal verbatim;
  6459 
  6460 * HOL: local contexts (aka cases) may now contain term bindings as
  6461 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6462 the result to be shown in each case;
  6463 
  6464 * HOL: added 'recdef_tc' command;
  6465 
  6466 * isatool convert assists in eliminating legacy ML scripts;
  6467 
  6468 
  6469 *** HOL ***
  6470 
  6471 * HOL/Library: a collection of generic theories to be used together
  6472 with main HOL; the theory loader path already includes this directory
  6473 by default; the following existing theories have been moved here:
  6474 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6475 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6476 
  6477 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6478 modelling and verification task performed in Isabelle/HOL +
  6479 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6480 
  6481 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6482 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6483 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6484 'domain', this makes the theory consistent with mathematical
  6485 literature;
  6486 
  6487 * HOL basics: added overloaded operations "inverse" and "divide"
  6488 (infix "/"), syntax for generic "abs" operation, generic summation
  6489 operator \<Sum>;
  6490 
  6491 * HOL/typedef: simplified package, provide more useful rules (see also
  6492 HOL/subset.thy);
  6493 
  6494 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6495 now expressed as a proper nested rule (old-style tactic scripts may
  6496 require atomize_strip_tac to cope with non-atomic premises);
  6497 
  6498 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6499 to "split_conv" (old name still available for compatibility);
  6500 
  6501 * HOL: improved concrete syntax for strings (e.g. allows translation
  6502 rules with string literals);
  6503 
  6504 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6505  and Fleuriot's mechanization of analysis, including the transcendental
  6506  functions for the reals;
  6507 
  6508 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6509 
  6510 
  6511 *** CTT ***
  6512 
  6513 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6514 "lam" is displayed as TWO lambda-symbols
  6515 
  6516 * CTT: theory Main now available, containing everything (that is, Bool
  6517 and Arith);
  6518 
  6519 
  6520 *** General ***
  6521 
  6522 * Pure: the Simplifier has been implemented properly as a derived rule
  6523 outside of the actual kernel (at last!); the overall performance
  6524 penalty in practical applications is about 50%, while reliability of
  6525 the Isabelle inference kernel has been greatly improved;
  6526 
  6527 * print modes "brackets" and "no_brackets" control output of nested =>
  6528 (types) and ==> (props); the default behaviour is "brackets";
  6529 
  6530 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6531 as assumptions as well;
  6532 
  6533 * system: support Poly/ML 4.0;
  6534 
  6535 * system: isatool install handles KDE version 1 or 2;
  6536 
  6537 
  6538 
  6539 New in Isabelle99-1 (October 2000)
  6540 ----------------------------------
  6541 
  6542 *** Overview of INCOMPATIBILITIES ***
  6543 
  6544 * HOL: simplification of natural numbers is much changed; to partly
  6545 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6546 issue the following ML commands:
  6547 
  6548   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6549   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6550 
  6551 * HOL: simplification no longer dives into case-expressions; this is
  6552 controlled by "t.weak_case_cong" for each datatype t;
  6553 
  6554 * HOL: nat_less_induct renamed to less_induct;
  6555 
  6556 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6557 fixsome to patch .thy and .ML sources automatically;
  6558 
  6559   select_equality  -> some_equality
  6560   select_eq_Ex     -> some_eq_ex
  6561   selectI2EX       -> someI2_ex
  6562   selectI2         -> someI2
  6563   selectI          -> someI
  6564   select1_equality -> some1_equality
  6565   Eps_sym_eq       -> some_sym_eq_trivial
  6566   Eps_eq           -> some_eq_trivial
  6567 
  6568 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6569 
  6570 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6571 instead);
  6572 
  6573 * HOL: the recursion equations generated by 'recdef' are now called
  6574 f.simps instead of f.rules;
  6575 
  6576 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6577 
  6578 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6579 sometimes be needed;
  6580 
  6581 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6582 
  6583 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6584 
  6585 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6586 product is now "<*>" instead of "Times"; the lexicographic product is
  6587 now "<*lex*>" instead of "**";
  6588 
  6589 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6590 of main HOL, but was unused); better use HOL's datatype package;
  6591 
  6592 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6593 the old syntax may be recovered as follows:
  6594 
  6595   syntax (symbols)
  6596     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6597       (infixl "\\<oplus>" 100)
  6598 
  6599 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6600 
  6601 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6602 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6603 internally;
  6604 
  6605 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6606 changed from A/r to A//r;
  6607 
  6608 * ZF: new treatment of arithmetic (nat & int) may break some old
  6609 proofs;
  6610 
  6611 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6612 rulify -> rule_format, elimify -> elim_format, ...);
  6613 
  6614 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6615 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6616 should have to change intro!! to intro? only); replaced "delrule" by
  6617 "rule del";
  6618 
  6619 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6620 
  6621 * Provers: strengthened force_tac by using new first_best_tac;
  6622 
  6623 * LaTeX document preparation: several changes of isabelle.sty (see
  6624 lib/texinputs);
  6625 
  6626 
  6627 *** Document preparation ***
  6628 
  6629 * formal comments (text blocks etc.) in new-style theories may now
  6630 contain antiquotations of thm/prop/term/typ/text to be presented
  6631 according to latex print mode; concrete syntax is like this:
  6632 @{term[show_types] "f(x) = a + x"};
  6633 
  6634 * isatool mkdir provides easy setup of Isabelle session directories,
  6635 including proper document sources;
  6636 
  6637 * generated LaTeX sources are now deleted after successful run
  6638 (isatool document -c); may retain a copy somewhere else via -D option
  6639 of isatool usedir;
  6640 
  6641 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6642 style files, achieving self-contained LaTeX sources and simplifying
  6643 LaTeX debugging;
  6644 
  6645 * old-style theories now produce (crude) LaTeX output as well;
  6646 
  6647 * browser info session directories are now self-contained (may be put
  6648 on WWW server seperately); improved graphs of nested sessions; removed
  6649 graph for 'all sessions';
  6650 
  6651 * several improvements in isabelle style files; \isabellestyle{it}
  6652 produces fake math mode output; \isamarkupheader is now \section by
  6653 default; see lib/texinputs/isabelle.sty etc.;
  6654 
  6655 
  6656 *** Isar ***
  6657 
  6658 * Isar/Pure: local results and corresponding term bindings are now
  6659 subject to Hindley-Milner polymorphism (similar to ML); this
  6660 accommodates incremental type-inference very nicely;
  6661 
  6662 * Isar/Pure: new derived language element 'obtain' supports
  6663 generalized existence reasoning;
  6664 
  6665 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6666 support accumulation of results, without applying any rules yet;
  6667 useful to collect intermediate results without explicit name
  6668 references, and for use with transitivity rules with more than 2
  6669 premises;
  6670 
  6671 * Isar/Pure: scalable support for case-analysis type proofs: new
  6672 'case' language element refers to local contexts symbolically, as
  6673 produced by certain proof methods; internally, case names are attached
  6674 to theorems as "tags";
  6675 
  6676 * Isar/Pure: theory command 'hide' removes declarations from
  6677 class/type/const name spaces;
  6678 
  6679 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6680 indicate potential overloading;
  6681 
  6682 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6683 
  6684 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6685 "{a,b,c}" instead of {a,b,c};
  6686 
  6687 * Isar/Pure now provides its own version of intro/elim/dest
  6688 attributes; useful for building new logics, but beware of confusion
  6689 with the version in Provers/classical;
  6690 
  6691 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6692 case name 'antecedent';
  6693 
  6694 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6695 to the current context is now done automatically);
  6696 
  6697 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6698 for definining proof methods in ML;
  6699 
  6700 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6701 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6702 most cases, one should have to change intro!! to intro? only);
  6703 replaced "delrule" by "rule del";
  6704 
  6705 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6706 'symmetric' attribute (the latter supercedes [RS sym]);
  6707 
  6708 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6709 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6710 well (including splits);
  6711 
  6712 * Isar/Provers: Simplifier and Classical methods now support all kind
  6713 of modifiers used in the past, including 'cong', 'iff', etc.
  6714 
  6715 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6716 of Simplifier and Classical reasoner);
  6717 
  6718 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6719 now support named cases; major packages (inductive, datatype, primrec,
  6720 recdef) support case names and properly name parameters;
  6721 
  6722 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6723 monotonicity conditions are extracted to be proven at end of
  6724 calculations;
  6725 
  6726 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6727 method anyway;
  6728 
  6729 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6730 split_if split_if_asm; datatype package provides theorems foo.splits =
  6731 foo.split foo.split_asm for each datatype;
  6732 
  6733 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6734 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6735 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6736 use "(cases (simplified))" method in proper proof texts);
  6737 
  6738 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6739 
  6740 * Isar: names of theorems etc. may be natural numbers as well;
  6741 
  6742 * Isar: 'pr' command: optional arguments for goals_limit and
  6743 ProofContext.prems_limit; no longer prints theory contexts, but only
  6744 proof states;
  6745 
  6746 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6747 additional print modes to be specified; e.g. "pr(latex)" will print
  6748 proof state according to the Isabelle LaTeX style;
  6749 
  6750 * Isar: improved support for emulating tactic scripts, including proof
  6751 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6752 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6753 (for HOL datatypes);
  6754 
  6755 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6756 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6757 'proof method scripts' have to be in depth-first order;
  6758 
  6759 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6760 
  6761 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6762 should instead use individual commands for printing items
  6763 (print_commands, print_methods etc.);
  6764 
  6765 * Isar: added 'nothing' --- the empty list of theorems;
  6766 
  6767 
  6768 *** HOL ***
  6769 
  6770 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6771 corresponding virtual machine and a specification of its bytecode
  6772 verifier and a lightweight bytecode verifier, including proofs of
  6773 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6774 Cornelia Pusch (see also the homepage of project Bali at
  6775 http://isabelle.in.tum.de/Bali/);
  6776 
  6777 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6778 Clemens Ballarin;
  6779 
  6780 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6781 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6782 Rasmussen;
  6783 
  6784 * HOL/Lattice: fundamental concepts of lattice theory and order
  6785 structures, including duals, properties of bounds versus algebraic
  6786 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6787 Theorem for complete lattices etc.; may also serve as a demonstration
  6788 for abstract algebraic reasoning using axiomatic type classes, and
  6789 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6790 
  6791 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6792 von Oheimb;
  6793 
  6794 * HOL/IMPP: extension of IMP with local variables and mutually
  6795 recursive procedures, by David von Oheimb;
  6796 
  6797 * HOL/Lambda: converted into new-style theory and document;
  6798 
  6799 * HOL/ex/Multiquote: example of multiple nested quotations and
  6800 anti-quotations -- basically a generalized version of de-Bruijn
  6801 representation; very useful in avoiding lifting of operations;
  6802 
  6803 * HOL/record: added general record equality rule to simpset; fixed
  6804 select-update simplification procedure to handle extended records as
  6805 well; admit "r" as field name;
  6806 
  6807 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6808 other numeric types and also as the identity of groups, rings, etc.;
  6809 
  6810 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6811 Types nat and int belong to this axclass;
  6812 
  6813 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6814    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6815    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6816   two terms #m*u and #n*u are replaced by #(m+n)*u
  6817     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6818   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6819     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6820 
  6821 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6822 powerful prover for predicate logic but knows nothing of clasets; see
  6823 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6824 
  6825 * HOL: new version of "case_tac" subsumes both boolean case split and
  6826 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6827 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6828 
  6829 * HOL: simplification no longer dives into case-expressions: only the
  6830 selector expression is simplified, but not the remaining arms; to
  6831 enable full simplification of case-expressions for datatype t, you may
  6832 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6833 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6834 
  6835 * HOL/recdef: the recursion equations generated by 'recdef' for
  6836 function 'f' are now called f.simps instead of f.rules; if all
  6837 termination conditions are proved automatically, these simplification
  6838 rules are added to the simpset, as in primrec; rules may be named
  6839 individually as well, resulting in a separate list of theorems for
  6840 each equation;
  6841 
  6842 * HOL/While is a new theory that provides a while-combinator. It
  6843 permits the definition of tail-recursive functions without the
  6844 provision of a termination measure. The latter is necessary once the
  6845 invariant proof rule for while is applied.
  6846 
  6847 * HOL: new (overloaded) notation for the set of elements below/above
  6848 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6849 
  6850 * HOL: theorems impI, allI, ballI bound as "strip";
  6851 
  6852 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6853 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6854 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6855 
  6856 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6857 
  6858 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6859 main HOL, but was unused);
  6860 
  6861 * HOL: fewer consts declared as global (e.g. have to refer to
  6862 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6863 
  6864 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6865 in case of overlap with user translations (e.g. judgements over
  6866 tuples); (note that the underlying logical represenation is still
  6867 bogus);
  6868 
  6869 
  6870 *** ZF ***
  6871 
  6872 * ZF: simplification automatically cancels common terms in arithmetic
  6873 expressions over nat and int;
  6874 
  6875 * ZF: new treatment of nat to minimize type-checking: all operators
  6876 coerce their operands to a natural number using the function natify,
  6877 making the algebraic laws unconditional;
  6878 
  6879 * ZF: as above, for int: operators coerce their operands to an integer
  6880 using the function intify;
  6881 
  6882 * ZF: the integer library now contains many of the usual laws for the
  6883 orderings, including $<=, and monotonicity laws for $+ and $*;
  6884 
  6885 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6886 simplification;
  6887 
  6888 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6889 to the simplifier and classical reasoner simultaneously;
  6890 
  6891 
  6892 *** General ***
  6893 
  6894 * Provers: blast_tac now handles actual object-logic rules as
  6895 assumptions; note that auto_tac uses blast_tac internally as well;
  6896 
  6897 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6898 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6899 
  6900 * Provers: delrules now handles destruct rules as well (no longer need
  6901 explicit make_elim);
  6902 
  6903 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6904   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6905 use instead the strong form,
  6906   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6907 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6908 from destruct-rules;
  6909 
  6910 * Provers: Simplifier.easy_setup provides a fast path to basic
  6911 Simplifier setup for new object-logics;
  6912 
  6913 * Pure: AST translation rules no longer require constant head on LHS;
  6914 
  6915 * Pure: improved name spaces: ambiguous output is qualified; support
  6916 for hiding of names;
  6917 
  6918 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6919 XSYMBOL_HOME; no longer need to do manual configuration in most
  6920 situations;
  6921 
  6922 * system: compression of ML heaps images may now be controlled via -c
  6923 option of isabelle and isatool usedir (currently only observed by
  6924 Poly/ML);
  6925 
  6926 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6927 useful for remote X11);
  6928 
  6929 * system: provide TAGS file for Isabelle sources;
  6930 
  6931 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6932 order;
  6933 
  6934 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6935 timing flag supersedes proof_timing and Toplevel.trace;
  6936 
  6937 * ML: new combinators |>> and |>>> for incremental transformations
  6938 with secondary results (e.g. certain theory extensions):
  6939 
  6940 * ML: PureThy.add_defs gets additional argument to indicate potential
  6941 overloading (usually false);
  6942 
  6943 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6944 results;
  6945 
  6946 
  6947 
  6948 New in Isabelle99 (October 1999)
  6949 --------------------------------
  6950 
  6951 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6952 
  6953 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6954 are no longer simplified.  (This allows the simplifier to unfold recursive
  6955 functional programs.)  To restore the old behaviour, declare
  6956 
  6957     Delcongs [if_weak_cong];
  6958 
  6959 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6960 complement;
  6961 
  6962 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6963 
  6964 * HOL/datatype: mutual_induct_tac no longer exists --
  6965   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6966 
  6967 * HOL/typedef: fixed type inference for representing set; type
  6968 arguments now have to occur explicitly on the rhs as type constraints;
  6969 
  6970 * ZF: The con_defs part of an inductive definition may no longer refer
  6971 to constants declared in the same theory;
  6972 
  6973 * HOL, ZF: the function mk_cases, generated by the inductive
  6974 definition package, has lost an argument.  To simplify its result, it
  6975 uses the default simpset instead of a supplied list of theorems.
  6976 
  6977 * HOL/List: the constructors of type list are now Nil and Cons;
  6978 
  6979 * Simplifier: the type of the infix ML functions
  6980         setSSolver addSSolver setSolver addSolver
  6981 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6982 for packaging solvers. A solver is created via
  6983         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6984 where the string argument is only a comment.
  6985 
  6986 
  6987 *** Proof tools ***
  6988 
  6989 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6990 decision procedure for linear arithmetic. Currently it is used for
  6991 types `nat', `int', and `real' in HOL (see below); it can, should and
  6992 will be instantiated for other types and logics as well.
  6993 
  6994 * The simplifier now accepts rewrite rules with flexible heads, eg
  6995      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6996   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6997   matching.
  6998 
  6999 
  7000 *** General ***
  7001 
  7002 * New Isabelle/Isar subsystem provides an alternative to traditional
  7003 tactical theorem proving; together with the ProofGeneral/isar user
  7004 interface it offers an interactive environment for developing human
  7005 readable proof documents (Isar == Intelligible semi-automated
  7006 reasoning); for further information see isatool doc isar-ref,
  7007 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7008 
  7009 * improved and simplified presentation of theories: better HTML markup
  7010 (including colors), graph views in several sizes; isatool usedir now
  7011 provides a proper interface for user theories (via -P option); actual
  7012 document preparation based on (PDF)LaTeX is available as well (for
  7013 new-style theories only); see isatool doc system for more information;
  7014 
  7015 * native support for Proof General, both for classic Isabelle and
  7016 Isabelle/Isar;
  7017 
  7018 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7019 using the graph browser tool;
  7020 
  7021 * Isabelle manuals now also available as PDF;
  7022 
  7023 * theory loader rewritten from scratch (may not be fully
  7024 bug-compatible); old loadpath variable has been replaced by show_path,
  7025 add_path, del_path, reset_path functions; new operations such as
  7026 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7027 isatool doc ref);
  7028 
  7029 * improved isatool install: option -k creates KDE application icon,
  7030 option -p DIR installs standalone binaries;
  7031 
  7032 * added ML_PLATFORM setting (useful for cross-platform installations);
  7033 more robust handling of platform specific ML images for SML/NJ;
  7034 
  7035 * the settings environment is now statically scoped, i.e. it is never
  7036 created again in sub-processes invoked from isabelle, isatool, or
  7037 Isabelle;
  7038 
  7039 * path element specification '~~' refers to '$ISABELLE_HOME';
  7040 
  7041 * in locales, the "assumes" and "defines" parts may be omitted if
  7042 empty;
  7043 
  7044 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7045 long arrows);
  7046 
  7047 * new print_mode "HTML";
  7048 
  7049 * new flag show_tags controls display of tags of theorems (which are
  7050 basically just comments that may be attached by some tools);
  7051 
  7052 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7053 mode and goal output format:
  7054 
  7055 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7056 244c244
  7057 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7058 ---
  7059 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7060 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7061 181c181
  7062 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7063 ---
  7064 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7065 
  7066 * function bind_thms stores lists of theorems (cf. bind_thm);
  7067 
  7068 * new shorthand tactics ftac, eatac, datac, fatac;
  7069 
  7070 * qed (and friends) now accept "" as result name; in that case the
  7071 theorem is not stored, but proper checks and presentation of the
  7072 result still apply;
  7073 
  7074 * theorem database now also indexes constants "Trueprop", "all",
  7075 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7076 
  7077 
  7078 *** HOL ***
  7079 
  7080 ** HOL arithmetic **
  7081 
  7082 * There are now decision procedures for linear arithmetic over nat and
  7083 int:
  7084 
  7085 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7086 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7087 are treated as atomic; subformulae not involving type `nat' or `int'
  7088 are ignored; quantified subformulae are ignored unless they are
  7089 positive universal or negative existential. The tactic has to be
  7090 invoked by hand and can be a little bit slow. In particular, the
  7091 running time is exponential in the number of occurrences of `min' and
  7092 `max', and `-' on `nat'.
  7093 
  7094 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7095 (negated) (in)equalities among the premises and the conclusion into
  7096 account (i.e. no compound formulae) and does not know about `min' and
  7097 `max', and `-' on `nat'. It is fast and is used automatically by the
  7098 simplifier.
  7099 
  7100 NB: At the moment, these decision procedures do not cope with mixed
  7101 nat/int formulae where the two parts interact, such as `m < n ==>
  7102 int(m) < int(n)'.
  7103 
  7104 * HOL/Numeral provides a generic theory of numerals (encoded
  7105 efficiently as bit strings); setup for types nat/int/real is in place;
  7106 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7107 int, existing theories and proof scripts may require a few additional
  7108 type constraints;
  7109 
  7110 * integer division and remainder can now be performed on constant
  7111 arguments;
  7112 
  7113 * many properties of integer multiplication, division and remainder
  7114 are now available;
  7115 
  7116 * An interface to the Stanford Validity Checker (SVC) is available through the
  7117 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7118 are proved automatically.  SVC must be installed separately, and its results
  7119 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7120 invocation of the underlying oracle).  For SVC see
  7121   http://verify.stanford.edu/SVC
  7122 
  7123 * IsaMakefile: the HOL-Real target now builds an actual image;
  7124 
  7125 
  7126 ** HOL misc **
  7127 
  7128 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7129 (in Isabelle/Isar) -- by Gertrud Bauer;
  7130 
  7131 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7132 analysis for assembly languages with subtypes;
  7133 
  7134 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7135 -- avoids syntactic ambiguities and treats state, transition, and
  7136 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7137 changed syntax and (many) tactics;
  7138 
  7139 * HOL/inductive: Now also handles more general introduction rules such
  7140   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7141   theorems are now maintained within the theory (maintained via the
  7142   "mono" attribute);
  7143 
  7144 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7145   (using function types) such as
  7146 
  7147   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7148 
  7149 * HOL/record: record_simproc (part of the default simpset) takes care
  7150 of selectors applied to updated records; record_split_tac is no longer
  7151 part of the default claset; update_defs may now be removed from the
  7152 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7153 
  7154   claset_ref () := claset() addSWrapper record_split_wrapper;
  7155   Delsimprocs [record_simproc]
  7156 
  7157 * HOL/typedef: fixed type inference for representing set; type
  7158 arguments now have to occur explicitly on the rhs as type constraints;
  7159 
  7160 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7161 names rather than an ML expression;
  7162 
  7163 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7164 supplied later.  Program schemes can be defined, such as
  7165     "While B C s = (if B s then While B C (C s) else s)"
  7166 where the well-founded relation can be chosen after B and C have been given.
  7167 
  7168 * HOL/List: the constructors of type list are now Nil and Cons;
  7169 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7170 course, ML tools referring to List.list.op # etc. have to be adapted;
  7171 
  7172 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7173 disabled by default; run isabelle with option -m HOL to get back to
  7174 the original Gordon/HOL-style output;
  7175 
  7176 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7177 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7178 
  7179 * HOL basic syntax simplified (more orthogonal): all variants of
  7180 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7181 Eps operator is provided as well: "SOME x. P[x]";
  7182 
  7183 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7184 
  7185 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7186 thus available for user theories;
  7187 
  7188 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7189 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7190 time;
  7191 
  7192 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7193 several times and then mp;
  7194 
  7195 
  7196 *** LK ***
  7197 
  7198 * the notation <<...>> is now available as a notation for sequences of
  7199 formulas;
  7200 
  7201 * the simplifier is now installed
  7202 
  7203 * the axiom system has been generalized (thanks to Soren Heilmann)
  7204 
  7205 * the classical reasoner now has a default rule database
  7206 
  7207 
  7208 *** ZF ***
  7209 
  7210 * new primrec section allows primitive recursive functions to be given
  7211 directly (as in HOL) over datatypes and the natural numbers;
  7212 
  7213 * new tactics induct_tac and exhaust_tac for induction (or case
  7214 analysis) over datatypes and the natural numbers;
  7215 
  7216 * the datatype declaration of type T now defines the recursor T_rec;
  7217 
  7218 * simplification automatically does freeness reasoning for datatype
  7219 constructors;
  7220 
  7221 * automatic type-inference, with AddTCs command to insert new
  7222 type-checking rules;
  7223 
  7224 * datatype introduction rules are now added as Safe Introduction rules
  7225 to the claset;
  7226 
  7227 * the syntax "if P then x else y" is now available in addition to
  7228 if(P,x,y);
  7229 
  7230 
  7231 *** Internal programming interfaces ***
  7232 
  7233 * tuned simplifier trace output; new flag debug_simp;
  7234 
  7235 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7236 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7237 
  7238 * AxClass.axclass_tac lost the theory argument;
  7239 
  7240 * tuned current_goals_markers semantics: begin / end goal avoids
  7241 printing empty lines;
  7242 
  7243 * removed prs and prs_fn hook, which was broken because it did not
  7244 include \n in its semantics, forcing writeln to add one
  7245 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7246 string -> unit if you really want to output text without newline;
  7247 
  7248 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7249 plain output, interface builders may have to enable 'isabelle_font'
  7250 mode to get Isabelle font glyphs as before;
  7251 
  7252 * refined token_translation interface; INCOMPATIBILITY: output length
  7253 now of type real instead of int;
  7254 
  7255 * theory loader actions may be traced via new ThyInfo.add_hook
  7256 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7257 your own database of information attached to *whole* theories -- as
  7258 opposed to intra-theory data slots offered via TheoryDataFun;
  7259 
  7260 * proper handling of dangling sort hypotheses (at last!);
  7261 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7262 extra sort hypotheses that can be witnessed from the type signature;
  7263 the force_strip_shyps flag is gone, any remaining shyps are simply
  7264 left in the theorem (with a warning issued by strip_shyps_warning);
  7265 
  7266 
  7267 
  7268 New in Isabelle98-1 (October 1998)
  7269 ----------------------------------
  7270 
  7271 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7272 
  7273 * several changes of automated proof tools;
  7274 
  7275 * HOL: major changes to the inductive and datatype packages, including
  7276 some minor incompatibilities of theory syntax;
  7277 
  7278 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7279 called `inj_on';
  7280 
  7281 * HOL: removed duplicate thms in Arith:
  7282   less_imp_add_less  should be replaced by  trans_less_add1
  7283   le_imp_add_le      should be replaced by  trans_le_add1
  7284 
  7285 * HOL: unary minus is now overloaded (new type constraints may be
  7286 required);
  7287 
  7288 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7289 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7290 now taken as an integer constant.
  7291 
  7292 * Pure: ML function 'theory_of' renamed to 'theory';
  7293 
  7294 
  7295 *** Proof tools ***
  7296 
  7297 * Simplifier:
  7298   1. Asm_full_simp_tac is now more aggressive.
  7299      1. It will sometimes reorient premises if that increases their power to
  7300         simplify.
  7301      2. It does no longer proceed strictly from left to right but may also
  7302         rotate premises to achieve further simplification.
  7303      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7304      old Asm_full_simp_tac in that it does not rotate premises.
  7305   2. The simplifier now knows a little bit about nat-arithmetic.
  7306 
  7307 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7308 allows for selected deletion of wrappers, by introduction of names for
  7309 wrapper functionals.  This implies that addbefore, addSbefore,
  7310 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7311 and that adding two tactics with the same name overwrites the first
  7312 one (emitting a warning).
  7313   type wrapper = (int -> tactic) -> (int -> tactic)
  7314   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7315   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7316   delWrapper, delSWrapper: claset *  string            -> claset
  7317   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7318 
  7319 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7320 semantics; addbefore now affects only the unsafe part of step_tac
  7321 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7322 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7323 by Force_tac;
  7324 
  7325 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7326 compWrapper; added safe wrapper (and access functions for it);
  7327 
  7328 * HOL/split_all_tac is now much faster and fails if there is nothing
  7329 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7330 and the names of the automatically generated variables have changed.
  7331 split_all_tac has moved within claset() from unsafe wrappers to safe
  7332 wrappers, which means that !!-bound variables are split much more
  7333 aggressively, and safe_tac and clarify_tac now split such variables.
  7334 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7335 Note: the same holds for record_split_tac, which does the job of
  7336 split_all_tac for record fields.
  7337 
  7338 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7339 permanently to the default simpset using Addsplits just like
  7340 Addsimps. They can be removed via Delsplits just like
  7341 Delsimps. Lower-case versions are also available.
  7342 
  7343 * HOL/Simplifier: The rule split_if is now part of the default
  7344 simpset. This means that the simplifier will eliminate all occurrences
  7345 of if-then-else in the conclusion of a goal. To prevent this, you can
  7346 either remove split_if completely from the default simpset by
  7347 `Delsplits [split_if]' or remove it in a specific call of the
  7348 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7349 other case splitting rules to/from the default simpset: every datatype
  7350 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7351 t is the name of the datatype).
  7352 
  7353 * Classical reasoner / Simplifier combination: new force_tac (and
  7354 derivatives Force_tac, force) combines rewriting and classical
  7355 reasoning (and whatever other tools) similarly to auto_tac, but is
  7356 aimed to solve the given subgoal completely.
  7357 
  7358 
  7359 *** General ***
  7360 
  7361 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7362 and `goalw': the theory is no longer needed as an explicit argument -
  7363 the current theory context is used; assumptions are no longer returned
  7364 at the ML-level unless one of them starts with ==> or !!; it is
  7365 recommended to convert to these new commands using isatool fixgoal
  7366 (backup your sources first!);
  7367 
  7368 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7369 the current theory context, and 'theory' to lookup stored theories;
  7370 
  7371 * new theory section 'locale' for declaring constants, assumptions and
  7372 definitions that have local scope;
  7373 
  7374 * new theory section 'nonterminals' for purely syntactic types;
  7375 
  7376 * new theory section 'setup' for generic ML setup functions
  7377 (e.g. package initialization);
  7378 
  7379 * the distribution now includes Isabelle icons: see
  7380 lib/logo/isabelle-{small,tiny}.xpm;
  7381 
  7382 * isatool install - install binaries with absolute references to
  7383 ISABELLE_HOME/bin;
  7384 
  7385 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7386 
  7387 * print mode 'emacs' reserved for Isamode;
  7388 
  7389 * support multiple print (ast) translations per constant name;
  7390 
  7391 * theorems involving oracles are now printed with a suffixed [!];
  7392 
  7393 
  7394 *** HOL ***
  7395 
  7396 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7397 
  7398 * HOL/inductive package reorganized and improved: now supports mutual
  7399 definitions such as
  7400 
  7401   inductive EVEN ODD
  7402     intrs
  7403       null "0 : EVEN"
  7404       oddI "n : EVEN ==> Suc n : ODD"
  7405       evenI "n : ODD ==> Suc n : EVEN"
  7406 
  7407 new theorem list "elims" contains an elimination rule for each of the
  7408 recursive sets; inductive definitions now handle disjunctive premises
  7409 correctly (also ZF);
  7410 
  7411 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7412 "mutual_induct" no longer exists - the induction rule is always
  7413 contained in "induct";
  7414 
  7415 
  7416 * HOL/datatype package re-implemented and greatly improved: now
  7417 supports mutually recursive datatypes such as
  7418 
  7419   datatype
  7420     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7421             | SUM ('a aexp) ('a aexp)
  7422             | DIFF ('a aexp) ('a aexp)
  7423             | NUM 'a
  7424   and
  7425     'a bexp = LESS ('a aexp) ('a aexp)
  7426             | AND ('a bexp) ('a bexp)
  7427             | OR ('a bexp) ('a bexp)
  7428 
  7429 as well as indirectly recursive datatypes such as
  7430 
  7431   datatype
  7432     ('a, 'b) term = Var 'a
  7433                   | App 'b ((('a, 'b) term) list)
  7434 
  7435 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7436 induction on mutually / indirectly recursive datatypes.
  7437 
  7438 Primrec equations are now stored in theory and can be accessed via
  7439 <function_name>.simps.
  7440 
  7441 INCOMPATIBILITIES:
  7442 
  7443   - Theories using datatypes must now have theory Datatype as an
  7444     ancestor.
  7445   - The specific <typename>.induct_tac no longer exists - use the
  7446     generic induct_tac instead.
  7447   - natE has been renamed to nat.exhaust - use exhaust_tac
  7448     instead of res_inst_tac ... natE. Note that the variable
  7449     names in nat.exhaust differ from the names in natE, this
  7450     may cause some "fragile" proofs to fail.
  7451   - The theorems split_<typename>_case and split_<typename>_case_asm
  7452     have been renamed to <typename>.split and <typename>.split_asm.
  7453   - Since default sorts of type variables are now handled correctly,
  7454     some datatype definitions may have to be annotated with explicit
  7455     sort constraints.
  7456   - Primrec definitions no longer require function name and type
  7457     of recursive argument.
  7458 
  7459 Consider using isatool fixdatatype to adapt your theories and proof
  7460 scripts to the new package (backup your sources first!).
  7461 
  7462 
  7463 * HOL/record package: considerably improved implementation; now
  7464 includes concrete syntax for record types, terms, updates; theorems
  7465 for surjective pairing and splitting !!-bound record variables; proof
  7466 support is as follows:
  7467 
  7468   1) standard conversions (selectors or updates applied to record
  7469 constructor terms) are part of the standard simpset;
  7470 
  7471   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7472 made part of standard simpset and claset via addIffs;
  7473 
  7474   3) a tactic for record field splitting (record_split_tac) is part of
  7475 the standard claset (addSWrapper);
  7476 
  7477 To get a better idea about these rules you may retrieve them via
  7478 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7479 the name of your record type.
  7480 
  7481 The split tactic 3) conceptually simplifies by the following rule:
  7482 
  7483   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7484 
  7485 Thus any record variable that is bound by meta-all will automatically
  7486 blow up into some record constructor term, consequently the
  7487 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7488 solve record problems automatically.
  7489 
  7490 
  7491 * reorganized the main HOL image: HOL/Integ and String loaded by
  7492 default; theory Main includes everything;
  7493 
  7494 * automatic simplification of integer sums and comparisons, using cancellation;
  7495 
  7496 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7497 
  7498 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7499 
  7500 * many new identities for unions, intersections, set difference, etc.;
  7501 
  7502 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7503 called split_if, split_split, split_sum_case and split_nat_case (to go
  7504 with add/delsplits);
  7505 
  7506 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7507 (?x::unit) = (); this is made part of the default simpset, which COULD
  7508 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7509 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7510 unit_abs_eta_conv is added in order to counter the effect of
  7511 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7512 %u.f();
  7513 
  7514 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7515 makes more sense);
  7516 
  7517 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7518   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7519   disjointness reasoning but breaking a few old proofs.
  7520 
  7521 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7522 to 'converse' from 'inverse' (for compatibility with ZF and some
  7523 literature);
  7524 
  7525 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7526 the well-founded relation;
  7527 
  7528 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7529     Compl A.  The "Compl" syntax remains available as input syntax for this
  7530     release ONLY.
  7531 
  7532 * HOL/Update: new theory of function updates:
  7533     f(a:=b) == %x. if x=a then b else f x
  7534 may also be iterated as in f(a:=b,c:=d,...);
  7535 
  7536 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7537 
  7538 * HOL/List:
  7539   - new function list_update written xs[i:=v] that updates the i-th
  7540     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7541   - new function `upt' written [i..j(] which generates the list
  7542     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7543     bound write [i..j], which is a shorthand for [i..j+1(].
  7544   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7545 
  7546 * HOL/Arith:
  7547   - removed 'pred' (predecessor) function;
  7548   - generalized some theorems about n-1;
  7549   - many new laws about "div" and "mod";
  7550   - new laws about greatest common divisors (see theory ex/Primes);
  7551 
  7552 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7553 instead of "inverse";
  7554 
  7555 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7556   of the multiset ordering;
  7557 
  7558 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7559   (not included by default);
  7560 
  7561 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7562 
  7563 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7564   programs, i.e. different program variables may have different types.
  7565 
  7566 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7567   [previously, this check worked only if the rewrite rule was unconditional]
  7568   Now rew can involve either definitions or equalities (either == or =).
  7569 
  7570 
  7571 *** ZF ***
  7572 
  7573 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7574   only the theorems proved on ZF.ML;
  7575 
  7576 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7577   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7578   disjointness reasoning but breaking a few old proofs.
  7579 
  7580 * ZF/Update: new theory of function updates
  7581     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7582   may also be iterated as in f(a:=b,c:=d,...);
  7583 
  7584 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7585 
  7586 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7587   [previously, this check worked only if the rewrite rule was unconditional]
  7588   Now rew can involve either definitions or equalities (either == or =).
  7589 
  7590 * case_tac provided for compatibility with HOL
  7591     (like the old excluded_middle_tac, but with subgoals swapped)
  7592 
  7593 
  7594 *** Internal programming interfaces ***
  7595 
  7596 * Pure: several new basic modules made available for general use, see
  7597 also src/Pure/README;
  7598 
  7599 * improved the theory data mechanism to support encapsulation (data
  7600 kind name replaced by private Object.kind, acting as authorization
  7601 key); new type-safe user interface via functor TheoryDataFun; generic
  7602 print_data function becomes basically useless;
  7603 
  7604 * removed global_names compatibility flag -- all theory declarations
  7605 are qualified by default;
  7606 
  7607 * module Pure/Syntax now offers quote / antiquote translation
  7608 functions (useful for Hoare logic etc. with implicit dependencies);
  7609 see HOL/ex/Antiquote for an example use;
  7610 
  7611 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7612 cterm -> thm;
  7613 
  7614 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7615 subgoal;
  7616 
  7617 * Display.print_goals function moved to Locale.print_goals;
  7618 
  7619 * standard print function for goals supports current_goals_markers
  7620 variable for marking begin of proof, end of proof, start of goal; the
  7621 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7622 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7623 for example;
  7624 
  7625 
  7626 
  7627 New in Isabelle98 (January 1998)
  7628 --------------------------------
  7629 
  7630 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7631 
  7632 * changed lexical syntax of terms / types: dots made part of long
  7633 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7634 
  7635 * simpset (and claset) reference variable replaced by functions
  7636 simpset / simpset_ref;
  7637 
  7638 * no longer supports theory aliases (via merge) and non-trivial
  7639 implicit merge of thms' signatures;
  7640 
  7641 * most internal names of constants changed due to qualified names;
  7642 
  7643 * changed Pure/Sequence interface (see Pure/seq.ML);
  7644 
  7645 
  7646 *** General Changes ***
  7647 
  7648 * hierachically structured name spaces (for consts, types, axms, thms
  7649 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7650 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7651 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7652 long_names for fully qualified output names; NOTE: ML programs
  7653 (special tactics, packages etc.) referring to internal names may have
  7654 to be adapted to cope with fully qualified names; in case of severe
  7655 backward campatibility problems try setting 'global_names' at compile
  7656 time to have enrything declared within a flat name space; one may also
  7657 fine tune name declarations in theories via the 'global' and 'local'
  7658 section;
  7659 
  7660 * reimplemented the implicit simpset and claset using the new anytype
  7661 data filed in signatures; references simpset:simpset ref etc. are
  7662 replaced by functions simpset:unit->simpset and
  7663 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7664 to patch your ML files accordingly;
  7665 
  7666 * HTML output now includes theory graph data for display with Java
  7667 applet or isatool browser; data generated automatically via isatool
  7668 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7669 
  7670 * defs may now be conditional; improved rewrite_goals_tac to handle
  7671 conditional equations;
  7672 
  7673 * defs now admits additional type arguments, using TYPE('a) syntax;
  7674 
  7675 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7676 creates a new theory node; implicit merge of thms' signatures is
  7677 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7678 transfer:theory->thm->thm in (rare) cases;
  7679 
  7680 * improved handling of draft signatures / theories; draft thms (and
  7681 ctyps, cterms) are automatically promoted to real ones;
  7682 
  7683 * slightly changed interfaces for oracles: admit many per theory, named
  7684 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7685 
  7686 * print_goals: optional output of const types (set show_consts and
  7687 show_types);
  7688 
  7689 * improved output of warnings (###) and errors (***);
  7690 
  7691 * subgoal_tac displays a warning if the new subgoal has type variables;
  7692 
  7693 * removed old README and Makefiles;
  7694 
  7695 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7696 
  7697 * removed obsolete init_pps and init_database;
  7698 
  7699 * deleted the obsolete tactical STATE, which was declared by
  7700     fun STATE tacfun st = tacfun st st;
  7701 
  7702 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7703 (which abbreviates $HOME);
  7704 
  7705 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7706 use isatool fixseq to adapt your ML programs (this works for fully
  7707 qualified references to the Sequence structure only!);
  7708 
  7709 * use_thy no longer requires writable current directory; it always
  7710 reloads .ML *and* .thy file, if either one is out of date;
  7711 
  7712 
  7713 *** Classical Reasoner ***
  7714 
  7715 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7716 tactics that use classical reasoning to simplify a subgoal without
  7717 splitting it into several subgoals;
  7718 
  7719 * Safe_tac: like safe_tac but uses the default claset;
  7720 
  7721 
  7722 *** Simplifier ***
  7723 
  7724 * added simplification meta rules:
  7725     (asm_)(full_)simplify: simpset -> thm -> thm;
  7726 
  7727 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7728 logics (again);
  7729 
  7730 * added prems argument to simplification procedures;
  7731 
  7732 * HOL, FOL, ZF: added infix function `addsplits':
  7733   instead of `<simpset> setloop (split_tac <thms>)'
  7734   you can simply write `<simpset> addsplits <thms>'
  7735 
  7736 
  7737 *** Syntax ***
  7738 
  7739 * TYPE('a) syntax for type reflection terms;
  7740 
  7741 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7742 
  7743 * pretty printer: changed order of mixfix annotation preference (again!);
  7744 
  7745 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7746 
  7747 
  7748 *** HOL ***
  7749 
  7750 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7751   with `addloop' of the simplifier to faciliate case splitting in premises.
  7752 
  7753 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7754 
  7755 * HOL/Auth: new protocol proofs including some for the Internet
  7756   protocol TLS;
  7757 
  7758 * HOL/Map: new theory of `maps' a la VDM;
  7759 
  7760 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7761 cancelling out common nat summands from =, <, <= (in)equalities, or
  7762 differences; simplification procedures nat_cancel_factor for
  7763 cancelling common factor from =, <, <= (in)equalities over natural
  7764 sums; nat_cancel contains both kinds of procedures, it is installed by
  7765 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7766 
  7767 * HOL/simplifier: terms of the form
  7768   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7769   are rewritten to
  7770   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7771   and those of the form
  7772   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7773   are rewritten to
  7774   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7775 
  7776 * HOL/datatype
  7777   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7778 
  7779   P(t_case f1 ... fn x) =
  7780      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7781         ...
  7782        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7783      )
  7784 
  7785   and a theorem `split_t_case_asm' of the form
  7786 
  7787   P(t_case f1 ... fn x) =
  7788     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7789         ...
  7790        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7791      )
  7792   which can be added to a simpset via `addsplits'. The existing theorems
  7793   expand_list_case and expand_option_case have been renamed to
  7794   split_list_case and split_option_case.
  7795 
  7796 * HOL/Arithmetic:
  7797   - `pred n' is automatically converted to `n-1'.
  7798     Users are strongly encouraged not to use `pred' any longer,
  7799     because it will disappear altogether at some point.
  7800   - Users are strongly encouraged to write "0 < n" rather than
  7801     "n ~= 0". Theorems and proof tools have been modified towards this
  7802     `standard'.
  7803 
  7804 * HOL/Lists:
  7805   the function "set_of_list" has been renamed "set" (and its theorems too);
  7806   the function "nth" now takes its arguments in the reverse order and
  7807   has acquired the infix notation "!" as in "xs!n".
  7808 
  7809 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7810 
  7811 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7812   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7813 
  7814 * HOL/record: extensible records with schematic structural subtyping
  7815 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7816 still lacks various theorems and concrete record syntax;
  7817 
  7818 
  7819 *** HOLCF ***
  7820 
  7821 * removed "axioms" and "generated by" sections;
  7822 
  7823 * replaced "ops" section by extended "consts" section, which is capable of
  7824   handling the continuous function space "->" directly;
  7825 
  7826 * domain package:
  7827   . proves theorems immediately and stores them in the theory,
  7828   . creates hierachical name space,
  7829   . now uses normal mixfix annotations (instead of cinfix...),
  7830   . minor changes to some names and values (for consistency),
  7831   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7832   . separator between mutual domain defs: changed "," to "and",
  7833   . improved handling of sort constraints;  now they have to
  7834     appear on the left-hand side of the equations only;
  7835 
  7836 * fixed LAM <x,y,zs>.b syntax;
  7837 
  7838 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7839 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7840 
  7841 
  7842 *** FOL and ZF ***
  7843 
  7844 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7845   with `addloop' of the simplifier to faciliate case splitting in premises.
  7846 
  7847 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7848 in HOL, they strip ALL and --> from proved theorems;
  7849 
  7850 
  7851 
  7852 New in Isabelle94-8 (May 1997)
  7853 ------------------------------
  7854 
  7855 *** General Changes ***
  7856 
  7857 * new utilities to build / run / maintain Isabelle etc. (in parts
  7858 still somewhat experimental); old Makefiles etc. still functional;
  7859 
  7860 * new 'Isabelle System Manual';
  7861 
  7862 * INSTALL text, together with ./configure and ./build scripts;
  7863 
  7864 * reimplemented type inference for greater efficiency, better error
  7865 messages and clean internal interface;
  7866 
  7867 * prlim command for dealing with lots of subgoals (an easier way of
  7868 setting goals_limit);
  7869 
  7870 
  7871 *** Syntax ***
  7872 
  7873 * supports alternative (named) syntax tables (parser and pretty
  7874 printer); internal interface is provided by add_modesyntax(_i);
  7875 
  7876 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7877 be used in conjunction with the Isabelle symbol font; uses the
  7878 "symbols" syntax table;
  7879 
  7880 * added token_translation interface (may translate name tokens in
  7881 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7882 the current print_mode); IMPORTANT: user print translation functions
  7883 are responsible for marking newly introduced bounds
  7884 (Syntax.mark_boundT);
  7885 
  7886 * token translations for modes "xterm" and "xterm_color" that display
  7887 names in bold, underline etc. or colors (which requires a color
  7888 version of xterm);
  7889 
  7890 * infixes may now be declared with names independent of their syntax;
  7891 
  7892 * added typed_print_translation (like print_translation, but may
  7893 access type of constant);
  7894 
  7895 
  7896 *** Classical Reasoner ***
  7897 
  7898 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7899 some limitations.  Blast_tac...
  7900   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7901   + ignores elimination rules that don't have the correct format
  7902         (the conclusion MUST be a formula variable)
  7903   + ignores types, which can make HOL proofs fail
  7904   + rules must not require higher-order unification, e.g. apply_type in ZF
  7905     [message "Function Var's argument not a bound variable" relates to this]
  7906   + its proof strategy is more general but can actually be slower
  7907 
  7908 * substitution with equality assumptions no longer permutes other
  7909 assumptions;
  7910 
  7911 * minor changes in semantics of addafter (now called addaltern); renamed
  7912 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7913 (and access functions for it);
  7914 
  7915 * improved combination of classical reasoner and simplifier:
  7916   + functions for handling clasimpsets
  7917   + improvement of addss: now the simplifier is called _after_ the
  7918     safe steps.
  7919   + safe variant of addss called addSss: uses safe simplifications
  7920     _during_ the safe steps. It is more complete as it allows multiple
  7921     instantiations of unknowns (e.g. with slow_tac).
  7922 
  7923 *** Simplifier ***
  7924 
  7925 * added interface for simplification procedures (functions that
  7926 produce *proven* rewrite rules on the fly, depending on current
  7927 redex);
  7928 
  7929 * ordering on terms as parameter (used for ordered rewriting);
  7930 
  7931 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7932 
  7933 * the solver is now split into a safe and an unsafe part.
  7934 This should be invisible for the normal user, except that the
  7935 functions setsolver and addsolver have been renamed to setSolver and
  7936 addSolver; added safe_asm_full_simp_tac;
  7937 
  7938 
  7939 *** HOL ***
  7940 
  7941 * a generic induction tactic `induct_tac' which works for all datatypes and
  7942 also for type `nat';
  7943 
  7944 * a generic case distinction tactic `exhaust_tac' which works for all
  7945 datatypes and also for type `nat';
  7946 
  7947 * each datatype comes with a function `size';
  7948 
  7949 * patterns in case expressions allow tuple patterns as arguments to
  7950 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7951 
  7952 * primrec now also works with type nat;
  7953 
  7954 * recdef: a new declaration form, allows general recursive functions to be
  7955 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7956 
  7957 * the constant for negation has been renamed from "not" to "Not" to
  7958 harmonize with FOL, ZF, LK, etc.;
  7959 
  7960 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7961 infinite lists;
  7962 
  7963 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7964 
  7965 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7966 problems in commutative rings, using axiomatic type classes for + and *;
  7967 
  7968 * more examples in HOL/MiniML and HOL/Auth;
  7969 
  7970 * more default rewrite rules for quantifiers, union/intersection;
  7971 
  7972 * a new constant `arbitrary == @x.False';
  7973 
  7974 * HOLCF/IOA replaces old HOL/IOA;
  7975 
  7976 * HOLCF changes: derived all rules and arities
  7977   + axiomatic type classes instead of classes
  7978   + typedef instead of faking type definitions
  7979   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7980   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7981   + eliminated the types void, one, tr
  7982   + use unit lift and bool lift (with translations) instead of one and tr
  7983   + eliminated blift from Lift3.thy (use Def instead of blift)
  7984   all eliminated rules are derived as theorems --> no visible changes ;
  7985 
  7986 
  7987 *** ZF ***
  7988 
  7989 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  7990 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  7991 as ZF_cs addSIs [equalityI];
  7992 
  7993 
  7994 
  7995 New in Isabelle94-7 (November 96)
  7996 ---------------------------------
  7997 
  7998 * allowing negative levels (as offsets) in prlev and choplev;
  7999 
  8000 * super-linear speedup for large simplifications;
  8001 
  8002 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8003 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8004 FAIL); can suppress it using the command Delsimps (ex_simps @
  8005 all_simps); De Morgan laws are also now included, by default;
  8006 
  8007 * improved printing of ==>  :  ~:
  8008 
  8009 * new object-logic "Sequents" adds linear logic, while replacing LK
  8010 and Modal (thanks to Sara Kalvala);
  8011 
  8012 * HOL/Auth: correctness proofs for authentication protocols;
  8013 
  8014 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8015 examples on HOL/Auth);
  8016 
  8017 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8018 the rewriter and classical reasoner simultaneously;
  8019 
  8020 * function uresult no longer returns theorems in "standard" format;
  8021 regain previous version by: val uresult = standard o uresult;
  8022 
  8023 
  8024 
  8025 New in Isabelle94-6
  8026 -------------------
  8027 
  8028 * oracles -- these establish an interface between Isabelle and trusted
  8029 external reasoners, which may deliver results as theorems;
  8030 
  8031 * proof objects (in particular record all uses of oracles);
  8032 
  8033 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8034 
  8035 * "constdefs" section in theory files;
  8036 
  8037 * "primrec" section (HOL) no longer requires names;
  8038 
  8039 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8040 
  8041 
  8042 
  8043 New in Isabelle94-5
  8044 -------------------
  8045 
  8046 * reduced space requirements;
  8047 
  8048 * automatic HTML generation from theories;
  8049 
  8050 * theory files no longer require "..." (quotes) around most types;
  8051 
  8052 * new examples, including two proofs of the Church-Rosser theorem;
  8053 
  8054 * non-curried (1994) version of HOL is no longer distributed;
  8055 
  8056 
  8057 
  8058 New in Isabelle94-4
  8059 -------------------
  8060 
  8061 * greatly reduced space requirements;
  8062 
  8063 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8064 
  8065 * searchable theorem database (see the section "Retrieving theorems" on
  8066 page 8 of the Reference Manual);
  8067 
  8068 * new examples, including Grabczewski's monumental case study of the
  8069 Axiom of Choice;
  8070 
  8071 * The previous version of HOL renamed to Old_HOL;
  8072 
  8073 * The new version of HOL (previously called CHOL) uses a curried syntax
  8074 for functions.  Application looks like f a b instead of f(a,b);
  8075 
  8076 * Mutually recursive inductive definitions finally work in HOL;
  8077 
  8078 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8079 translates to the operator "split";
  8080 
  8081 
  8082 
  8083 New in Isabelle94-3
  8084 -------------------
  8085 
  8086 * new infix operator, addss, allowing the classical reasoner to
  8087 perform simplification at each step of its search.  Example:
  8088         fast_tac (cs addss ss)
  8089 
  8090 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8091 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8092 look like (a,b) instead of <a,b>;
  8093 
  8094 * PLEASE NOTE: CHOL will eventually replace HOL!
  8095 
  8096 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8097 It translates to the operator "split".  A new theory of integers is available;
  8098 
  8099 * In ZF, integer numerals now denote two's-complement binary integers.
  8100 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8101 
  8102 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8103 of the Axiom of Choice;
  8104 
  8105 
  8106 
  8107 New in Isabelle94-2
  8108 -------------------
  8109 
  8110 * Significantly faster resolution;
  8111 
  8112 * the different sections in a .thy file can now be mixed and repeated
  8113 freely;
  8114 
  8115 * Database of theorems for FOL, HOL and ZF.  New
  8116 commands including qed, qed_goal and bind_thm store theorems in the database.
  8117 
  8118 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8119 a given theory (thms_of), or find out what theory a theorem was proved in
  8120 (theory_of_thm);
  8121 
  8122 * Bugs fixed in the inductive definition and datatype packages;
  8123 
  8124 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8125 and HOL_dup_cs obsolete;
  8126 
  8127 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8128 have been removed;
  8129 
  8130 * Simpler definition of function space in ZF;
  8131 
  8132 * new results about cardinal and ordinal arithmetic in ZF;
  8133 
  8134 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8135 types;
  8136 
  8137 :mode=text:wrap=hard:maxLineLen=72: